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PV Audio
10-26-2005, 02:13 PM
this thread was inspired by another member stating that it would be good to have a general guide to loudspeakers, so here's all i know. every member is welcome to add or change anything i say to correct terms. this is to clear up the misconceptions and confusions in loudspeaker design.

Let's start on speaker drivers themselves, and with that, a little on sound.

General sound

The audible range of sound is roughly 20hz-20khz. This means that anything below 20hz is subsonic (infrasonic) and i am not aware of the term for above 20khz. This means, speakers that try to sell you on frequency responses up to 25khz are not worth the extra money unless you are a dog. Now, this does not hold the same for infrasonic waves. These waves while inaudible, are rather felt. Because of the wavelength of the sound, they fluctuate less and thus travel through barriers. An easy way to think of this is by taking a sword. Drive that sword (soundwave) into the ground. It goes into the ground. Crumple the sword, and try it again. It just bounces off (this is similar to high frequencies).

Within the audible range of sound, there are different regions. We shall start from the bottom and go up. We start with infrasonic bass (1hz-19hz). Now, from 20hz to around 60-80 hz is called subbass. The drivers used for this are subwoofers. More on the word later. From around 80-500 can be considered the bass to midbass region. The drivers used for these are woofers. Now from there up to around 2khz is the bandpass or midrange region. These drivers are obviously midrange cones. These most often are paper coned speakers anywhere from 3"-6.5" in diameter and are generally in typical cone shapes, domes or planar. From about 2.5khz to 20khz are the high frequencies. These drivers are tweeters and most generally range from 3" to 1/2". Planar or ribbon tweeters are very popular for this sound range.

Most subbass drivers are very large, because to make large sound, you must move large air. This concept also makes sense if you think about Jurassic Park. Who wants to listen to dinosaur steps that sound like you are tapping a dixie cup? These diameters are generally 18" up to multiples of 5"-8" drivers. Most commonly, 12" subwoofers are used, and most HTIB setups are either a few 6.5" speakers in bandpass boxes.

When selecting a speaker to use in a cabinet, it is most often useful to know the specs of the speaker. More importantly, it is useful to know what those specs mean :)

I'll give you a run down on some basic terms, and suggestions on clarification and correction are very welcome.

A - Attenuation, loss of db
B - Magnetic flux density in gap
Bl - Electro-magnetic force factor
BL - Driver motor strength
Cab - Acoustic compliance of air in the enclosure
Cas - Acoustical equivalent of Cms
Cmes - The electrical capacitive equivalent of Mms
Cms - The driver's mechanical compliance (reciprocal of stiffness)
D - Effective diameter of driver
F3 - -3 dB cutoff frequency
Fb - Enclosure resonance (usually for reflex systems)
Fc - System resonance (usually for sealed box systems)
Fs - Driver free air resonance. This is the point at which driver impedance is maximum
Lces - The electrical inductive equivalent of Cms
Le - Driver inductance (voice coil, mainly)
Levc - Driver voice coil inductance
Mas - Acoustical equivalent of Mms
Mms - The driver's effective mechanical mass (including air load)
n0 - The reference efficiency of the system
p - Density of air at STP 1.18 kg/m^3 (rho)
Pa - Acoustical power)
Pe - Electrical power)

Vd - Venerial disease :D No, but for real. It is the volume of air displaced by the speaker. A word on this: DO NOT TAKE THIS NUMBER AS DEFINITE. Many people assume that more Vd = louder sound. Most cones are rather the same size (same diameter cones i'm talking about) and those with a similar xmax will have a similar Vd. But why are some of these tailored to SPL and some to SQ? If you don't believe me, here is an example. My dayton 15" has 21mm of xmax. My DD 9515 has 13mm of xmax. THe dd walks on the dayton in spl, even though technically they have a similar Vd. Reason Vd doesn't account for pure, all out SPL is because Vd takes distortion and linear output into account. For musical listening, we only want our subwoofers to function in a linear, relatively low-distortion manor. For SPL, distortion and linear output goes out the window. All we care about is moving as much air as possible, so they can push the subwoofer well beyond it's linear limitations and out to it's mechanical limitations (Xmech) Vd is calculated by multiplying the xmax by the Sd.

Ras - Acoustical equivalent of Rms
Re - Driver DC resistance (voice coil, mainly)
Revc - DC resistance of the voice coil only
Rg - Amplifier source resistance (includes leads, crossover, etc.)
Sd - Effective piston radiating (surface) area of driver
Vab - The volume of air having the same acoustic compliance as the enclosures
Vas - The volume of air having the same acoustic compliance as the driver suspension: Cms
Vb - Net internal volume of enclosure
Xmax - Maximum peak linear excursion of driver
Z - Total driver impedance

Q (es) (ts) (ms) (tc) - Q stands for "Quality Factor", which describes the ratio of energy stored to the energy dissipated. These are very useful tools when designing a cabinet. For the sake of time and people not liking to read, Qts is generally the only useful tool in PRELIMINARY cabinet construction (Qtc, someone else can explain that because i'm not too sure). Qts it the total Q of a speaker, thus Qes and Qms. A lower Qts driver is generally suited for a ported enclosure (.3>), higher values (.7<) are suited for sealed enclosures. The median values can either be used for other enclosure types. Qtc describes the total "Q" of the "system" (driver in the enclosure). Qts is used to indicate the low frequency behavior of the subwoofer. Qtc is used to indicate the low frequency behavior of the system; ringing/overshoot/decay, frequency response, low frequency extension, group delay, etc. How does this tie into the stored/dissipated energy ratio? Well, the higher the Q(tc), the higher the ratio of energy storage compared enery dissipated....resulting in "ringing" and slow decay, and an underdamped response. The lower the Q(tc), the opposite, less ringing and faster decay, and an overdamped response. A Qtc of .707 is said to have maximally flat requency response and lowest F3, with a transient response (ringing, overshoot, etc) that is "not too bad". Good graphical representation here: http://www.carstereo.com/help/Articles.cfm?id=29 I SHOULD ALSO MENTION THAT THIS IS THE TIP OF THE TIP OF THE ICEBERG ON PARAMETERS
Enclosure types

Let me see, where to start.

Vented (ported) are very common enclosures at they most usually are used in subwoofers, which people seem to take the most notice to. The port on these enclosures is used to enhance or bring out a sound around a certain frequency that the enclosure is tuned to. Using damping materials in these enclosures can also smooth out the sound much like in sealed boxes.

Sealed are very common because they are simple. 6 pieces of wood, some glue and maybe a bit of alcohol and u have yourself a sealed box. While these may seem to be easy and not very difficult to design, this is not the case. These have the tendency to be "peaky" in higher frequency ranges. They also have a tendency to require smoothing in certain response ranges. This is where the use of damping materials comes into play. Eggcrate foam, fiberglass, Dacron, pillow stuffing or Polyfill is very popular to use to dampen these waves.

Bandpass enclosures are also common because they are easy to **** up and be loud :D no, but really these are probably THE most commonly used speaker designs in the commericial budget subwoofer market. Nearly, actually i'd venture to say that EVERY HTIB has a bandpass subwoofer. All bose subwoofers are actually bandpass as well. They are very tedious to design and generally do not perform well on paper or in the physical. I have heard one good bandpass, and that is unfortunately a bose. The enclosure consists of a variation of one half of the driver firing into a sealed enclosure, and the other half firing into a ported enclosure. These are VERY hard, mine you VERY VERY hard to get correct, but they are the best for sheer output when other options are either impractical or undesirable.


Horns: Here is a brief overview of how horns work via Dan Wiggins: Horns operate on the principle of a lever and dispersion control. A high pressure, low velocity end (the throat) is connected via an air-load to a low pressure, high velocity end (the flare end). SPL is the integral of velocity, meaning that if we can double the velocity at the end of the horn, we can increase the effective SPL by a corresponding amount. Longer, slower flare rates tend to amplify the effect, and is why high SPL horns are quite long with slow flare rates. Radiation angle is also affected by the flare shape, meaning that dispersion is reduced, so the output from the off-axis angles is reduced, and that energy is redirected into the on-axis (in the flare angle) of the horn, further increasing output. This is why you can find horns that will have outputs beyond 112 dB SPL in their beam angle - a theoretically "impossible" number, since 100% efficiency is 112 dB SPL! Of course, that is for a full-space radiation pattern; cutting down the radiation angle means one can reach levels higher than 112 dB SPL over a narrowed dispersion range.

There are alot of other types that are less popular such as transmission line, DBR (double bass reflex) and passive radiator, infinite baffle and isobaric.

That is all for now, i'll probably update it later with more stuff when i get home, probably a general overview on filters.

- Dave :)

Single spaced parameters courtesy of Michael Lalena

ballstothewall
10-26-2005, 04:34 PM
Sticky??? I believe this thread will be sticky worth when we get some more input from a few other members.

Wow, I learned something today, and it sure wasen't from the classes I'm paying out the *** for.

noob with an RS
10-26-2005, 04:57 PM
hmm.. interesting. so i have my car system crossed over at 52 hz. my idmax plays up 2 52 hz.. and my infinity perfect components are playing from 52 hz and up.. do u guys think i should raise my crossover point? the reason im asking is because above, it says 80 hz and up are played by woofers.

squeak9798
10-26-2005, 05:03 PM
Too lazy to do a full write-up, so a few quick thoughts:

Reason Vd doesn't account for pure, all out SPL is because Vd takes distortion and linear output into account. For musical listening, we only want our subwoofers to function in a linear, relatively low-distortion manor. For SPL, distortion and linear output goes out the window. All we care about is moving as much air as possible, so they can push the subwoofer well beyond it's linear limitations and out to it's mechanical limitations (Xmech)


Q stands for "Quality Factor", which describes the ratio of energy stored to the energy dissipated. This ties in to Qtc...


Qtc describes the total "Q" of the "system" (driver in the enclosure). Qts is used to indicate the low frequency behavior of the subwoofer. Qtc is used to indicate the low frequency behavior of the system; ringing/overshoot/decay, frequency response, low frequency extension, group delay, etc. How does this tie into the stored/dissipated energy ratio? Well, the higher the Q(tc), the higher the ratio of energy storage compared enery dissipated....resulting in "ringing" and slow decay, and an underdamped response. The lower the Q(tc), the opposite, less ringing and faster decay, and an overdamped response. A Qtc of .707 is said to have maximally flat requency response and lowest F3, with a transient response (ringing, overshoot, etc) that is "not too bad". Good graphical representation here: http://www.carstereo.com/help/Articles.cfm?id=29


Here is a brief overview of how horns work via Dan Wiggins: Horns operate on the principle of a lever and dispersion control. A high pressure, low velocity end (the throat) is connected via an air-load to a low pressure, high velocity end (the flare end). SPL is the integral of velocity, meaning that if we can double the velocity at the end of the horn, we can increase the effective SPL by a corresponding amount. Longer, slower flare rates tend to amplify the effect, and is why high SPL horns are quite long with slow flare rates. Radiation angle is also affected by the flare shape, meaning that dispersion is reduced, so the output from the off-axis angles is reduced, and that energy is redirected into the on-axis (in the flare angle) of the horn, further increasing output. This is why you can find horns that will have outputs beyond 112 dB SPL in their beam angle - a theoretically "impossible" number, since 100% efficiency is 112 dB SPL! Of course, that is for a full-space radiation pattern; cutting down the radiation angle means one can reach levels higher than 112 dB SPL over a narrowed dispersion range.

thylantyr
10-26-2005, 05:15 PM
http://electronics.howstuffworks.com/speaker.htm :woot:

flakko
10-26-2005, 05:19 PM
whhere is BL?

PV Audio
10-26-2005, 06:16 PM
thanks everyone, i put in the new information :)

PV Audio
10-26-2005, 06:17 PM
thylantr, care to do a write up on line arrays? i take u as the resident expert :)

perhaps on the use of phase plugs as well?

PV Audio
10-26-2005, 06:21 PM
oh and if y'all want something added, send me or post the info and i'll edit it into it. y'all better, cause i spent my lunch period writing this stuff :)

thylantyr
10-26-2005, 08:20 PM
thylantr, care to do a write up on line arrays? i take u as the resident expert :)

perhaps on the use of phase plugs as well?

The hard work has already been done on line array babble.
http://www.audiodiycentral.com/resource/pdf/nflawp.pdf

if this isn't enough, in that document there is 11 references too :cool:

Re: phase plugs
<McCoy aka Bones - Star Trek>"Jim... I'm a doctor not a scientist" :hilariou:

Here is one resource on that topic but it's a different phase plug
http://www.eaw.com/technology/proprietary/phaseplug.html

You see them installed on high frequency cone drivers to 'help' high frequency response
because the dust cap 'svcks'. .. and if you are clever and make a solid metal one with
thermal joint compound it helps as a heatsink to cool the speaker, a bonus. But some
phase plugs are of the phoney variety were the cone is just glued on the cone, so there
is no heatsinking.

PV Audio
10-26-2005, 08:24 PM
no see, that is why i wanted u to write something lol. i don't want babble, i want things people understand. you won't learn if you don't understand the material :)

thylantyr
10-26-2005, 08:27 PM
no see, that is why i wanted u to write something lol. i don't want babble, i want things people understand. you won't learn if you don't understand the material :)

The Jim Griffin document is as easy as it gets. He took the complicated data
and made it easy to understand.

Maybe just ask questions about the document itself to make it even easier?

PV Audio
10-26-2005, 08:27 PM
i added new parameters, going to start on what i know about filters after geometry stops taking me prisoner

PV Audio
10-26-2005, 08:29 PM
The Jim Griffin document is as easy as it gets. He took the complicated data
and made it easy to understand.

Maybe just ask questions about the document itself to make it even easier?
no i mean, i don't know what is really important and what people don't need to know in full. thats why i wanted ur run down, hence not like 50 pgs going into detail, just the most important things to know.

PV Audio
10-26-2005, 08:32 PM
what is sound>20khz called

XtrmAudioCncpts
10-26-2005, 08:37 PM
wow good write up

PV Audio
10-26-2005, 08:37 PM
thanks, and thanks to everyone who has contributed thus far.

PV Audio
10-26-2005, 08:42 PM
amplifier gurus, any input is appreciated

LBX2G
10-26-2005, 08:42 PM
thnx for my cheat sheet......now to summarize ur info


ps........what about the different types of enclosures especially free-air :))

PV Audio
10-26-2005, 08:44 PM
what do u mean summarize...

what enclosure is free air...unless you mean infinite baffle? i'm reading a few Small articles on it right now and i'll have a synopsis later unless someone else is good enough to have the info right now (you know who you are) :)

JimJ
10-26-2005, 08:45 PM
Maybe he's talking about dipole setups...which actually would be a cool writeup to have, I remember seeing an article once about needed baffle sizes to reproduce different frequencies. Something like a 9 meter-high baffle is needed to produce sub-30Hz bass response free-air :)

PV Audio
10-26-2005, 08:47 PM
ahh indeed, i think jlaine is the man for that job however (this is just after talking to him though).

LBX2G
10-26-2005, 08:51 PM
what do u mean summarize...

what enclosure is free air...unless you mean infinite baffle? i'm reading a few Small articles on it right now and i'll have a synopsis later unless someone else is good enough to have the info right now (you know who you are) :)
no i am going to make a cheat sheet like they sell for math in ur college book store.

PV Audio
10-26-2005, 09:01 PM
ahh even though i don't kno nothin bout college (still 16 for teh win) :)

PV Audio
10-26-2005, 09:46 PM
can we get a sticky?

PV Audio
10-26-2005, 10:27 PM
Now that that is taken care of, onto some general cabinet construction tips, some superfluous, some important

When cutting the cabinet, it is a good idea to cut a few millimeters or 1/8" wide for good measure. This way, you can have over hang OR you will be dead on the correct measurement. The only reason for this is because when using circular saws, or table saws inparticular, most people dont account for the blade which is usally 1/8 or more by itself. By cutting them wide, you have a margin of error and can then just throw in a flush trim bit on the router and go to town for a fine finish.

The circle is the most important part of the enclosure, otherwise, where would the speaker go? :D

One good thing to do when making the cutout is to flush mount the cone. This makes it essentially a part of the baffle, thus keeping the drivers on the same plane as the baffle. This generally increases imaging and soundstage. Another tip is to make sure that the drivers are not equidstant from any baffle edge. While there is come disagreement on this, it doesn't hurt to try as long as the width is large enough to matter. Another good suggestion is to round-over the rear of the baffle. This essentially "unchokes" the air from the rear of the cone. For example, if you are using a small midrange in 1" plywood, the air from the rear of that cone has no space to go to. This is just a good tip if you want to do all that you can to improve the small things about your speaker.

Bracing is VERY important in both subwoofers and loudspeakers. While in subwoofers bracing is used for the reduction of flexing, in both subwoofers and loudspeakers effective bracing is IDEAL to cut down on cabinet resonance. Bracing effectively makes the cabinet ONE piece of wood rather than six. By increasing the rigidity of the structure, you are essentially strengthing it and allowing less unwanted noise in the enclosure. Think about it like this. You are a scrawny person holding a heavy barbell. Your arms quiver and shake from the weight. When someone helps you, or BRACES your arms, the quivering stops. While this is an elementary way of thinking, it is still quite relative.

There are three types of bracing, and one is more effective than the other two. They are listed in order of effectiveness, highest to lowest. The three main types are shelf braces, span braces (many names for these) and corner braces. The shelf braces couple all four sides. Imagine putting a shelf inside of a sub box. It is connected to the front baffle, rear baffle and the sides. These are now coupled to create a single piece. When a brace is put in the vertical direction as well, you are gold. These braces have holes cut into them so as not to impede airflow within the cabinet, but not so much as the integral strength of the brace is jeopardized. The problem with shelf braces is that they take up precious Vb. If you don't have a lot of room to spare (most trunks are on space constraints :) ) read on. The next brace, the span brace, couples two sides together. An example is a 1.5 x .75 inch piece of wood running the distance from the front to the back. This only couples two sides which is better than nothing. Very commonly used in enclosures that are tight on space as they are more effective than the last brace, the corner brace. This is just a square piece of wood placed in the corner between two cabinet sides. These are not ideal as the probability that the brace is LITERALLY on the sides is nil (unless screwed in, when the glue dries it sometimes takes it away from the corresponding wood) and thus possible jeopardizing the effective bracing qualities of the brace. However, these take up very little room as well and are common in small bookshelf speakers where a shelf is obviously impractical and a span brace may impede either a port or the driver itself.

Wood itself is probably the second most important part of a speaker (you don't HAVE to use wood, as apparently the closest to natural speaker was an aluminum honey comb tower from the 1970s, according to various authors) next to the driver. Wood materials are VERY important when considering what you want the enclosure to sound like. Believe it or not, wood makes a sound when acted upon. For most enclosures, the relative stiffness of MDF as well as it's damping quality makes it very popular. However, to get truly the best sound for your money, a good plywood has always shown to be superior. These woods are rather expensive though. By plywood, I don't mean the chipboard used for underlayments, I mean the plywood that is multiple layers thick and resembles flooring. Baltic birch is a personal favorite of mine, as well as oak. The damping characteristics of the plywood are better and have a tendency to resonate LESS than MDF (as said by Small in an article from the 70's, just so u don't think i'm makin that up :) ). However, for most builders, MDF is ideal because it is relatively cheap, sounds good, is better than particleboard and can be easily found and cut.

PV Audio
10-27-2005, 12:14 AM
sumone add somethin

thylantyr
10-27-2005, 12:55 AM
amplifier gurus, any input is appreciated

<American Indian voice>"Take small signal .. make into big signal" :waycrazy:

thylantyr
10-27-2005, 01:26 AM
When cutting the cabinet, it is a good idea to cut a few millimeters or 1/8" wide for good measure. This way, you can have over hang OR you will be dead on the correct measurement. The only reason for this is because when using circular saws, or table saws inparticular, most people dont account for the blade which is usally 1/8 or more by itself. By cutting them wide, you have a margin of error and can then just throw in a flush trim bit on the router and go to town for a fine finish.

On my tablesaw, every cut I make is precision and the box is glued to perfection.
It's harder to do with a circular saw, jig saw, hand saw, etc. Tablesaw rules.
I think it's better to train yourself to do precision cuts than to settle for loose
tolerance cutting, eventually you will be happier this way as it's less work.

I mean the plywood that is multiple layers thick and resembles flooring. Baltic birch is a personal favorite of mine, as well as oak.

Baltic Birch at the local lumber store here is 14 ply, $202 for 3/4" , 4x8 sheet. /ouch
It's strong because of the laminations but will resonate in a similar fashion
to ordinary 7 ply wood, knock on it and you'll see [or hear it, hehe}.

Typical oak, birch, maple, etc plywood {$50/sheet} at the home centers
is 7 ply, the only thing 'oak', 'birch', 'maple', etc., about this wood is just the
very thin veneer, the inner layers are usually other types of cheaper
wood, perhaps fir or whatever. Because you pay premium for this 'veneered'
plywood, they try to make the quality of the sheet better with less voids to
because you expect it to be this way. If you don't need the fancy veneer
*and* can find good quality 'construction' grade plywood then it will perform
just as well for less money.

The damping characteristics of the plywood are better and have a tendency to resonate LESS than MDF (as said by Small in an article from the 70's, just so u don't think i'm makin that up :) ).

30 year old article? /hehe

MDF pros for loudspeakers;

* cheaper than veneered plywoods, marine plywood, baltic birch
* it doesn't warp like plywood
* weights 2x more than typical plywood which gives it a lower resonant frequency, damps higher frequencies better.
* machines well
* smooth surface for painting

Plywood pros for loudspeakers;

* more robust cabinets for other industries {DJ, proaudio, etc.}
* lighter weight + bracing can be very effective too.
* if veneered plywood, will finish well with stains, lacquers, etc.

What else?

When is your book going to be released ? :)

squeak9798
10-27-2005, 11:30 AM
what is sound>20khz called

Supersonic

squeak9798
10-27-2005, 12:22 PM
This would be a good thread to toss out some formula's aswell :) Such as;

Theoretical increase in output due to increase in power:

10*log(power1/power2)

10*log(2/1) = 3.0103db

Double power = 3db increase

Increase in output due to displacement:

20*log(Vd1/Vd2)

20*log(2/1) = 6.0206db

20*log(1.413/1) = 3.003db

Double displacement = 6db
41.3% displacement increase = 3db

Resonant Frequency;

Fs = [6.28(Cms * Md)^1/2]^-1

Sensitivity;

SPL = 112 + 10*log(9.64 * 10^(-10) * Fs^3 * Vas/Qes)

Efficiency;

N0 = 9.64 * 10^(-10) * Fs^3 * Vas/Qes

Qts;

Qts = Qes * Qms / ( Qms + Qes )

Sealed enclosures:

Vb = Vas/[(Qtc/Qts)^2-1]

Fb = (Qtc/Qts)*Fs

F3 = Fb*((1/Qtc^2-2+((1/Qtc^2-2)^2+4)^0.5)/2)^0.5

PV Audio
10-27-2005, 12:53 PM
When cutting the cabinet, it is a good idea to cut a few millimeters or 1/8" wide for good measure. This way, you can have over hang OR you will be dead on the correct measurement. The only reason for this is because when using circular saws, or table saws inparticular, most people dont account for the blade which is usally 1/8 or more by itself. By cutting them wide, you have a margin of error and can then just throw in a flush trim bit on the router and go to town for a fine finish.

On my tablesaw, every cut I make is precision and the box is glued to perfection.
It's harder to do with a circular saw, jig saw, hand saw, etc. Tablesaw rules.
I think it's better to train yourself to do precision cuts than to settle for loose
tolerance cutting, eventually you will be happier this way as it's less work.

I mean the plywood that is multiple layers thick and resembles flooring. Baltic birch is a personal favorite of mine, as well as oak.

Baltic Birch at the local lumber store here is 14 ply, $202 for 3/4" , 4x8 sheet. /ouch
It's strong because of the laminations but will resonate in a similar fashion
to ordinary 7 ply wood, knock on it and you'll see [or hear it, hehe}.

Typical oak, birch, maple, etc plywood {$50/sheet} at the home centers
is 7 ply, the only thing 'oak', 'birch', 'maple', etc., about this wood is just the
very thin veneer, the inner layers are usually other types of cheaper
wood, perhaps fir or whatever. Because you pay premium for this 'veneered'
plywood, they try to make the quality of the sheet better with less voids to
because you expect it to be this way. If you don't need the fancy veneer
*and* can find good quality 'construction' grade plywood then it will perform
just as well for less money.

The damping characteristics of the plywood are better and have a tendency to resonate LESS than MDF (as said by Small in an article from the 70's, just so u don't think i'm makin that up :) ).

30 year old article? /hehe

MDF pros for loudspeakers;

* cheaper than veneered plywoods, marine plywood, baltic birch
* it doesn't warp like plywood
* weights 2x more than typical plywood which gives it a lower resonant frequency, damps higher frequencies better.
* machines well
* smooth surface for painting

Plywood pros for loudspeakers;

* more robust cabinets for other industries {DJ, proaudio, etc.}
* lighter weight + bracing can be very effective too.
* if veneered plywood, will finish well with stains, lacquers, etc.

What else?

When is your book going to be released ? :)
I learn something new every day :)

the reason why i said about cutting wide is because not everyone on these forums can afford a good table saw. you might as well cut wide and trim than cut short and make it sloped. my book? naw..i don't know alot :) gotta learn :)

thylantyr
10-27-2005, 02:05 PM
I learn something new every day :)

Don't assume everything I say is golden :laugh: If it makes sense, go with the
flow ...:evil:

thylantyr
10-27-2005, 02:22 PM
If you can find an old table saw this size
http://woozy.com/coppermine/albums/userpics/tablesaw/DSCN3716.JPG.800.jpg

you can rebuild it.

If you don't have space in the garage for lots of tools you can maybe
make a tablesaw cabinet on wheels like I did. It's a multi-function cabinet,
rectagular in shape with six casters. I removed the saw legs and placed
the saw on the cabinet center and sealed it up so it collects dust and hole
for a shop vac interface to **** dust out later when it fills. To the right side
of this cabinet I installed another box, the router table and it's lined up with
the saw table. On my tablesaw fence I made an attachment that slips on,
this fence is the router fences and it has a chamber that the shop vac
connects to.. to **** dust during table top routing. You can make your
own sleds too. This is a rolling cabinet so I can move it aside when not in use
and the extra dead space in the cabinet is used to store my other tools,
clamps, drills, jigsaw, circular saw, etc. The cabinet has no doors because it's
just easier to leave it without.

If you find an old tablesaw you can upgrade to a better fence, but killer fences
aren't cheap either. I bought the big azz fence so I can rip wider sheets, you
pay premium for a longer throw fence.

If you have a big budget and lots of shop space, I really like those big azz
radial arm saws that have uber stroke to cut 4 x 8 sheets. It's so easy..
To cut a 4 x 8 sheet on the regular saw you need another person to help
hold the wood and you have to slide the wood across the table and to get
a perfect cut is harder because the wood is heavy.

The lumber yard may have one of those radial arm saws, all they do is
place the sheet on the table, clamp it, and drag the saw across the wood
for perfection, and you can do it alone. Pretty sweet. :yumyum:

PV Audio
10-27-2005, 04:29 PM
pretty good info

thylantyr
10-27-2005, 06:16 PM
Re: non tablesaw cutting, ie circular saw, jigsaw.

Try this and let me know. If you cut plywood the dreaded chip out happens,
try laying down a piece of masking tape on the cut line, both sides of the wood,
then cut the wood and remove the tape after.:evil:
[you can do this on a tablesaw too.. but usually people user course blades on
circular saws that give you chipout]

PV Audio
10-27-2005, 08:46 PM
^^ indeed, i noticed that when i got my birch. i had lowes cut it ( :mad: table saw doesn't work, circ saw blade is green so we don't need green paint on the fine wood ;) ) It chipped pretty good.

ballstothewall
10-27-2005, 11:06 PM
Routering dovetails in baltic birch trying to minimize chipout is a pain it the ***... That is the one part i don't like about making drawers for furniture. Unless i cut down some walnut down to 1/2" for the drawer, then its all good.

jaygeorge1979
10-29-2005, 11:53 AM
methinks i like this thread

PV Audio
10-29-2005, 12:40 PM
indeed, there has been alot of contribution.

JimJ
11-01-2005, 05:53 AM
Well, it's early in the morning, and I figure this thread could use something else. So let's talk tube numbers and naming schemes :D

This seems to be a point of confusion for a lot of people starting out in tube audio...and you really need to know the terminology in order to make decisions about what to buy - after all, an EL34 amp and EL84 amp are two very different things. We'll just look at the European (Mullard/Phillips) and the US scheme, because those are the two most common you see on the used and new tube markets.

European system:

First letter: Filament
A 4V
B 0.18A (series)
C 0.2A (series)
D <= 1.4V (series/parallel)
E 6.3V (series/parallel)
F 12.6V
G 5V (parallel)
H 0.15A (series)
K 2V
L 0.45A (series)
P 0.3A (series)
U 0.1A (series)
V 0.05A (series)
X 0.6A (series)
Y 0.45A (series)

Second and subsequent letters: construction
A Diode (excluding rectifier)
B Double diode
C Triode (signal, not power)
D Power output triode
E Tetrode (signal, not power)
F Pentode (signal, not power)
L Power output tetrode or pentode
H Hexode or heptode (of the hexode type)
K Octode or heptode (of the octode type)
M Tuning indicator
Q Nonode.
Y Half wave rectifier
Z Full wave rectifier

First digit: Basing
1 Miscellaneous
2 Miniature 10 pin
3 International octal (eight pins)
4 8-pin miniature (B8A)
5 Magnoval (B9D)
8 Noval (B9A - nine pins)
9 Miniature (B7G)

Example: If you find a tube and its box is marked "EZ81", then you've stumbled across a full wave rectifier that has a 6.3V filament voltage and fits a standard 9-pin socket. Or the commonly found EL84 is a power pentode with a 6.3V voltage and a 9-pin base. The EL34 differs in that it has an octal base (the 3 shows that) but other than that, it's simply a larger version of the '84. In practice, it works very similar to that - a single ended amp with the tubes wired in triode mode with EL84's does around 3wpc, while the same wiring scheme with '34s will up the power output to 6wpc.

http://www.wiwitubes.com/pic/tube/APX6ca7~el34.jpghttp://www.dougstubes.com/images/Ei%20EL84.jpg

EL34's on the left, EL84's on the right.

American system:

First number: filament voltage
0 Cold cathode (e.g. voltage regulator tube).
1 0.1 - 2.0
2 2.1 - 2.9
3 3.0 - 3.9
n n.0 - n.9

Letter or letters: sequence code
One or two letters to indicate the sequence code. When the single character codes were used up, double character codes were introduced.
Note that U - Z generally (but not always) as the only character, or last character, are used for rectifiers

Final number: Element count
The number of elements in the tube, the filament counting as 1. For example, the 6SN7 has two cathodes, two grids, two plates, and a filament.

Additional letters:
A Controlled heater warmup time, although can also be used to denote increased ratings or performance over and above the non-A model.
B Improved ratings/performance.
C Ditto.
G Glass bulb.
GT Glass tubular.
W Ruggedised version.
X Low loss ceramic base.
Y Low loss phenolic base.

The type designator is a sequentially assigned letter, or pair of
letters. Other than the fact that they started assigning rectifiers
in reverse order, the letter doesn't mean anything. When they ran
out of single letters, they used two. So a 12AX7 is a 12-volt signal input triode that has seven elements and has a 9-pin base. In that tube, there
are two cathodes, two grids, two plates, and a heater that make up the elements.

Furthermore, you can have different types of tube envelopes themselves...you can have a "coke bottle" shaped tube (G) suffix; straight-sided (GB), and a smaller coke bottle shape (GA). However, tubes that are marked like this might have other differences...for example, the 5U4G and 5U4GB are really different tubes, as the 'GB version can supply slightly more voltage. But the two are generally interchangeable in most circuits.

http://www.hupse.nl/radio/tube_images/5U4GB.jpghttp://www.teletone.com/images/NU-5U4G.jpg

A 5U4GB is shown on the left, and an older style 'G is shown at right.

That's all for now, will include more when I get the urge to...like a detailed listing of all the tubes we're interested in for audio purposes and the different naming games that go on with that. I can't begin to figure it all out. But if you want to get into this sort of thing, it helps to know that a 6CA7 is the same thing as an EL34, or a 6BQ5 means an EL84, or a 6CA4...you get the picture. Can't do anything unless you speak the langauge first.

PV Audio
11-01-2005, 02:10 PM
ok yeah i think this deserves a sticky now. EXCELLENT stuff, and thanks for posting it jack.

JimJ
11-04-2005, 09:39 PM
continuing a little theme here...

Push Pull v. Single Ended amplifiers
and why you should care...

Not found often in solid state electronics (where PP MOSFETs reign supreme), the differences between push pull output stages and single ended ones should be considered when looking at vacuum tube amps, as they're two very different beasts built for different applications. Each topology has certain benefits and drawbacks...PP amps are generally more powerful, but lack some of the tone and "presence" that SETs often have.

Push-Pull:

In a push-pull amplifier the power supply is connected to the center-tap of the transformer and a tube is connected to both the upper and lower end of the center-tapped primary. This allows the tubes to conduct on alternate cycles of the input waveform. A push-pull stage can be biased class A, where current flows in both tubes for the entire input cycle (but in opposite directions), or class AB, where current flows alternately in both halves, but less than a full cycle in each, or class B, where current flows only half the time in each tube. Most designs are biased class AB for best efficiency and power output with minimal crossover distortion (but not necessarily best "tone").

http://www.aikenamps.com/PP.gif

A push-pull stage requires at least two tubes to operate, but can have more connected in parallel with each side, resulting in an amp with four, six, or even eight output tubes for higher-power amps. This is called "parallel push-pull" operation. Another advantage of the push-pull circuit is that there is little or no unbalanced DC current in the output transformer if the tubes are matched and the output stage is balanced, since current flows in opposite directions to each tube, allowing a smaller transformer with less iron (translation: cheaper). Also, even order harmonics and distortion products generated in the output stage are canceled out. In addition, power supply hum is canceled out, allowing the designer to get by with less filtering of the power supply. This stage generally clips symmetrically, resulting in more odd harmonic distortion.

SE operation:

A single-ended amp output stage is always run class A. The output transformer primary is not center-tapped, having only two connections. One connection goes to the power supply, the other to the plate of the power tube or tubes. Tubes can also be paralleled for more power as in a push-pull stage, resulting in what is called "parallel single-ended".

http://www.aikenamps.com/SE.gif

The single-ended stage is found in both modern high-end vacuum tube amplifiers and countless millions of early radios and TV's. It is as inefficient as it is good sounding, putting out very low power levels in comparison to push-pull output stages. Another problem with this type of stage is the transformer must handle a continuous DC current. This results in a physically larger and more costly output transformer, which must be gapped to prevent saturation of the core due to this offset DC current.

Crossover distortion is eliminated in SE operation, because the output devices are always on - only having one per channel elimates switching them on and off. This, however, contributes to the design's inefficiency. Theoretically, SE amps have a maximum efficiency of 25%, but in the real world you're doing well to break 20%.

In a SET design, the transformers are the most expensive part of the amp, with the iron basically the limiting factor on the frequency response. You don't want to skimp here when designing a SE amp.

Disadvantages of single-ended include: no rejection of power supply hum, which mandates heavier filtering to keep the hum to acceptable levels (although there are several workarounds for PSU hum that render it almost negligible), no rejection of even order harmonics, and generally asymmetrical limiting on overloads which further emphasizes even order harmonics (which are more pleasing to the ear than odd order harmonics). These "disadvantages" give the single-ended output stage a unique tone, compared to the push-pull output stage. Whether it is "better" or not is a matter of taste.

ballstothewall
02-04-2006, 11:52 PM
One question....

WHY ISN'T THIS A STICKY?

PV Audio
02-04-2006, 11:54 PM
Not sure, I think that it should have been.

PV Audio
02-05-2006, 12:54 AM
Someone needs to contribute something..

ballstothewall
02-05-2006, 01:02 AM
I would if I could..:(

PV Audio
02-05-2006, 01:07 AM
Bro, you built a BLH...you obviously know something about woodworking.

ballstothewall
02-05-2006, 01:10 AM
Eh, building a BLH was easy actually, even the 206e design for their 8" driver looks pretty easy to build. But let me see if I can come up with some woodworking stuff that hasen't already been covered. May take me a little while though...

PV Audio
02-05-2006, 01:12 AM
Anyone that works with walnut obviously has some sort of skill.

ballstothewall
02-05-2006, 01:14 AM
Ok ok ok, I will type something up, give me a day to work it up, gotta test coming up.

PV Audio
02-05-2006, 01:14 AM
Geah, that's what it is. :)

PV Audio
02-05-2006, 03:29 PM
Gah, i'm out of good info to share for right now.

joetama
02-05-2006, 04:03 PM
The reason for a speaker element that will efficiently produce sounds over 20kHz is sounds in the ultrasonic or supersonic range still affect the audible frequencies. For example if you have a 1 kHz freq played through a system also playing a 2.5 kHz frequency it's going to affect the sound that is heard. Well the same goes for frequencies over 20 kHz. It's usually considered that 30 kHz is the point where the affective mixing of frequencies is no longer important enough to reproduce, however Sennheiser has done research with their recording mics that show sound up to 40 kHz still affects sound as low as 1 kHz. Also, if you have a piston tweeter or planer tweeter (really any tweeter with moving mass) and they will effectively go up beyond the point of true audible sound, 20 kHz, the diaphragm will act more like a perfect piston up to and the 20 kHz point. Meaning the break-up frequency is much higher, consequently causing less distortion and a cleaner brighter high end.

Ctesibius
02-05-2006, 04:11 PM
For example if you have a 1 kHz freq played through a system also playing a 2.5 kHz frequency it's going to affect the sound that is heard. Well the same goes for frequencies over 20 kHz. It's usually considered that 30 kHz is the point where the affective mixing of frequencies is no longer important enough to reproduce, however Sennheiser has done research with their recording mics that show sound up to 40 kHz still affects sound as low as 1 kHz.

CD's are presently only capable of storing data up to ~22khz. It is physically impossible for a regular CD to contain information above this point, as it is half of the sampling rate.

JimJ
02-05-2006, 04:12 PM
Part of why I don't like CDs if fidelity is a concern :)

PV Audio
02-05-2006, 04:16 PM
Jim, sticky?

joetama
02-05-2006, 04:19 PM
CD's are presently only capable of storing data up to ~22khz. It is physically impossible for a regular CD to contain information above this point, as it is half of the sampling rate.
That's why I listen to SACD's or DVD-Audio almost only...

PV Audio
02-05-2006, 04:22 PM
If I could afford a SACD player then I'd buy them.

JimJ
02-05-2006, 04:23 PM
If I could afford a SACD player then I'd buy them.

There are some under the $200 price point, I believe...

Problem is, SACD has even slower sales than vinyl, so not a lot of stuff gets released to it.

joetama
02-05-2006, 04:27 PM
CD's are presently only capable of storing data up to ~22khz. It is physically impossible for a regular CD to contain information above this point, as it is half of the sampling rate.
Plus if the System has a response over 20k the performance below 20k is improved...

joetama
02-05-2006, 04:30 PM
Let it load, go to the University of Sound, then watch the thing on Diamond Dome Tweeters....

http://www.bwspeakers.com/bw800/flash_en.html

PV Audio
02-05-2006, 05:30 PM
Can we get a sticky on this so I don't have to keep bumping it?

PV Audio
02-05-2006, 05:46 PM
Good link B&W. The guy talking about the cabinets sounded like he was dying.

joetama
02-05-2006, 09:16 PM
Ha, typical english engineer lol...

PV Audio
02-05-2006, 09:16 PM
UHHH the UM matrix UHM, it's UHM...

joetama
02-05-2006, 09:25 PM
Diamond tweeters and reverse horn loadeding mmm lol....

PV Audio
02-05-2006, 09:29 PM
Yeah...

BassAce
02-05-2006, 09:44 PM
This reminds me, the new VD is out. I wish I can get it:crap: .


































http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=500-035&raid=25&rak=speakerbuild&wt.sv1

Too bad it costs ~$35, someone want to buy it for me to support education.

joetama
02-05-2006, 09:54 PM
Ha, I'm lucky if i get a college book for that!!!

ballstothewall
02-05-2006, 10:05 PM
Ha, I'm lucky if i get a college book for that!!!

God, college books for that price would be AWSOME!

PV Audio
02-05-2006, 10:08 PM
Where's the sticky?

joetama
02-05-2006, 10:18 PM
God, college books for that price would be AWSOME!
If I would of purchased all new books insted of going half and half and buying used I would of spend something like $175 on 3 books!!! Now that *****....

BassAce
02-05-2006, 11:17 PM
If I would of purchased all new books insted of going half and half and buying used I would of spend something like $175 on 3 books!!! Now that *****....

College books are bad, my books this semester were just under $400. I had to buy those nearly a month ago and I don't have enough extra money to buy my favorite book. I'd love to get my hands on that book by Vance Dickason, didn't google or the library of congress did a thing where the scanned every single book?

The Home Audio/Video section does need a sticky, this is all good info.

joetama
02-05-2006, 11:22 PM
Amazon was scanning books to be sold as digital copies and the library of congress stocks every book printed in the US... And WOW that's expencive.

The book I love is "How To Build Speaker Enclosures" by Alexis Badmaieff and Don Davis; but it was last in print in 1975. It's one of the most well rounded build books I've ever got my hands on...

thylantyr
02-05-2006, 11:26 PM
If I could afford a SACD player then I'd buy them.

Get a universal DVD player, plays everyting. You can get one for under $125.
I did my own auditions and found most that modern sources are pretty advanced
even for budget consumer grade stuff. Good electronics was hard to get 20-30
years ago, but his is year 2006, replicating audio is simple on the source level.

I have no idea why people think 20hz - 20khz is hard to reproduce when we have
semiconductors able to operate in gigahertz range. Audio electronics is a mature
science today. The real key to success is the speakers. Even Earl Geddes agrees if
you don't believe me :cool: I've listened to SACD, it's no big deal, to me it's just a
hair less noisy than CD. DVD-A is nothing special either.

Spend your most of your money on speakers and adequate power, then room
treatments.

PV Audio
02-06-2006, 05:13 PM
:mad:

jalverson
02-06-2006, 05:14 PM
If you didn't create this thread, it would probably be a sticky ... :fyi:


**** thats a burn for sure mang:up2somet: you gonna just take that PV?

JimJ
02-06-2006, 05:14 PM
you gonna just take that PV?

What else is he going to do...:)

PV Audio
02-06-2006, 05:14 PM
Lol, what can I do?

PV Audio
02-06-2006, 05:14 PM
See? Tulip knows.

joetama
02-06-2006, 05:17 PM
He'll take it and then ask for some more lol....JK

JimJ
02-06-2006, 05:19 PM
http://www.tsny.com/otto/images/snapple/16ozDtLemTea.jpg

Just fits perfectly.

PV Audio
02-06-2006, 05:27 PM
Y'all some cold mothers.

Illie
02-06-2006, 05:30 PM
hahahaha

james is always keepin the black man down!

jalverson
02-06-2006, 05:31 PM
:spank: OWNED
PV-JIMJ




















J/K

Beat_Dominator
02-06-2006, 05:37 PM
hehe.

PV Audio
02-06-2006, 05:57 PM
You wankers.

joetama
02-06-2006, 06:19 PM
You wankers.
Wankers??? I'm more English than you are and I dont even say that....

PV Audio
02-06-2006, 06:38 PM
Hmm, how about bloody gits?

One of my good friends is British :)

joetama
02-06-2006, 06:45 PM
Nice...

PV Audio
02-06-2006, 06:48 PM
Quite.

ngsm13
02-06-2006, 07:02 PM
I concur.

NG

PV Audio
02-07-2006, 05:35 PM
Truly.

joetama
02-07-2006, 10:02 PM
Or not...

PV Audio
02-07-2006, 10:36 PM
Anyway, I need ballstothewall to do his writeup.

ballstothewall
02-07-2006, 11:06 PM
Anyway, I need ballstothewall to do his writeup.

Calc test thursday, Macroeconomics test monday, U.S. Politics test tuesday, and a trip to Mississippi on friday-sunday.


All in due time my fellow audio addicts, all in due time.

PV Audio
02-07-2006, 11:13 PM
Yeah, it's DUE at THIS TIME!

:)

joetama
02-07-2006, 11:13 PM
That ***** arse....

ballstothewall
02-07-2006, 11:16 PM
I'm workin on tryin to pass the **** calc test first man.

ballstothewall
02-15-2006, 01:25 AM
Quick Rundown on Woodworking

Ok, some of you guys may be thinking, “I’ve built a few boxes for some subs, they sounded good, I know my way around a wood shop.” Wrong. First off, if you are still in high school, take a woods class, and take it as much as you can, it is one of the best places to learn carpenter tricks. Some bonus of woods classes in high school is cheap wood -oak, walnut, or pine usually- good tools kept in good working condition, and they usually are stocked with LOTS of tools and table space.

Always take the motto of “Measure twice, cut once” to heart, if necessary measure three or four times, then cut. You should believe me when I say this (although you won’t) it is A LOT cheaper to make the cuts right the first time. You have no idea how much of a pain it is to screw up a piece of beautiful walnut with a bad measurement and have to remake one that doesn’t look near as good because you used all the good wood you have already (been there, done that).

Table saws are an AWSOME tool to have in a shop. If you are in the market for one, don’t skimp on it. When you get it in your shop, make a table that extends out to the right of the blade at least 60” but try for 90” so you can cut a full 4’x8’ sheet of plywood on it easily. Buy the best quality aluminum fence that you can, once again don’t skimp here. The out-feed table is something that is sometimes overlooked, ok, you can cut a wide board, but what happens when it falls off the table half way through a cut? It isn’t hard to make a table to help “tail-off” the stock, or just get some ball bearing rollers and go at it from that angle. Which ever way you look at it, you NEED to have extra table space to the right of the blade and to the back.

When selecting a miter gauge I would suggest having two of them, a fixed one and an adjustable one. If you have an option, get ones constructed out of aluminum that way they don’t spark if/when you cut them with the blade. The adjustable one is for the 45 degree cuts etc, for everything else, use the fixed one; it is more accurate and doesn’t come loose.

When looking at the blades you can buy for a table saw or router bits or anything with a sharp edge, GET CARBIDE. Carbide edged blades will stay sharp for a long time if you are using them for personal use. Keep in mind that carbide is very strong, but also very brittle and if you drop one, it will break the carbide off of a couple teeth. If you are getting really nitpicky about what you are doing, better find another blade to put on instead of the cracked one. Another bonus of carbide, the stuff that is used in the saw blades, shaper heads, router bits, etc, is the same grade of carbide that is used to cut aluminum, so if/when you nick your equipment, no biggie, it doesn’t hurt the blade.

When working with any type of wood, oak, walnut, pine, birch, cottonwood, any type of wood that ISN”T a plywood. If the board is wider than six inches, you need to make it out of multiple boards, this is so it doesn’t warp. Say if you have a board that you need a board rough size of 1.5’x4’ you would need three boards 6”x4’, using a biscuit jointer putting biscuits in about 6” from each end and 10”-14” in between throughout the rest of the joint. Now before you biscuit any board, you HAVE to run them through the jointer or table saw depending on what exactly you are doing and how you cut them. The sides have to fit flush together, any gap over (my rule of thumb here) 1/32” is unacceptable and you need to re-run across the jointer in order to get it correct. Once you have the sides square and flush with the biscuits cut in them, time to glue. I assume you know how to glue, so stick some clamps on them, and glue.

Once glue is dry, you need to find yourself a glue scraper and go to town and get all the excess glue off of the project BEFORE you try to sand it. If you sand it before the glue is off, you ruin your sand paper. You will be severely pissed if someone else runs a non scrapped board through the drum sander and the sand paper is ruined when you need to use it, believe me, I’ve been the pissed one.
My favorite tool to sand is a random orbital sander, it works awesome to knock down rises and get out scratches, but you do have to be careful not to make divots in your board with it because it does work fast. After that I move up to a pad sander with 80/120/180 grit sand paper to do the finish sanding.

When working with Walnut, you will have A LOT of scratches to get out, it isn’t near as hard as Oak, and shows scratches very well, so if it looks like a scratch, it is, and no your not done sanding. Walnut takes A LOT of work to get it to look perfect, but when you do, it is beautiful.
Remember, a properly built enclosure is a lot better then having a poor constructed box with a lot of caulking, the perfect cuts and glue to hold the project together will be you caulk, you should need nothing else in order to seal it.


Things I would recommend for a shop
Table Saw*
Clamps (lots of them)*
90 degree corner clamps, they are like 8 bucks and worth every penny*
Jointer*
Sander
A big work table
Power miter box
Radial Arm saw

The ones with the “*” beside them, that is what I would deem necessary in a shop, everything else is nice, but you don’t HAVE to have. If you get into furniture making, cabinetry, stuff more complicated than speaker boxes –for example, a futon recliner-- you will be better off with more tools.



If requested, I might be able to throw something together on dado joints, a little bit on finishing, and possibly some other stuff as I think of it. This is a work in progress that I threw together in 30 minutes; bear with the bad grammar and misspellings. These words are not to be meant as God’s word, just some ramblings of a wood worker, if you want pictures evidence of my work, I can get them for you. But if you don’t, you will just have to take my word for my competence in a wood shop. If you have questions, feel free to PM me or post them up, I don’t mean to try to say that I am all knowing, but I know a little something about working in a wood shop (well maybe more than a little about woodworking).


:crazy: 2 pages in microsoft word....

ballstothewall
02-15-2006, 01:27 AM
If more is requested, or I am just wasting my effort typing this, let me know, I could provide a lot more info, but I wasen't sure on how much would be pointless and how much is requested. I know alot more about furniture and that stuff, but the building techniques are the same nevertheless.

I WANT YOUR FEEDBACK.

swc204
02-15-2006, 01:38 AM
sounds about right

you don't need to explain furniture making or joints because they need to be taught in person at a wood shop class to learn right....

post some pics of your work if you have any. I would post some of mine but i just sold some pieces and my camera took a dump on me, but i might take some when i make some chairs this weekend if i can get a camera...

ballstothewall
02-15-2006, 01:41 AM
I will try to get some pics when I go home this weekend for ya'll.

Beat_Dominator
02-15-2006, 02:12 PM
I learned it all from watching the New Yankee workshop......

JimJ
02-15-2006, 02:44 PM
How to get fat and wear plaid? Because Norm does those really well ;)

He's like the audiophile of woodworking, if that makes any sense. Those cabinets must have been better, because I made them with my brand-new Vermont American automatic three-in-one high horsepower biscuit maker. They'll hold 100 more pounds than your regular cabinet will, and wax your floors, too.

As for me, I'm a fan of "The Woodwright's Shop..."

:D

thylantyr
02-15-2006, 04:47 PM
I learned it all from watching the New Yankee workshop......

/rant

A long time ago I built stuff from just oak plywood and just trimmed the edges
with solid oak pieces. I was just using the common sense card because I didn't
want to solve my cabinet problem using complex woodworking methods.

I didn't have the facility to make a solid oak cabinet where you need to
glue each board and run it through the joiner/planer, etc... and it's expensive.

To me, the oak plywood is good enough as it does have a coarse veneer
layer that stains and finishes well. Actually I prefer the coarse veneer over
the real veneers you buy as they look too artificial.

I've watched many Yankee shows and his methods are great. Recently,
I saw him make a cabinet out of oak plywood and I laughed thinking to myself,
done that 19 years ago.. and "you are cheating Norm, slaps his hand". But, it takes
someone like him to give the methology credibility. :crazy: even thought the common
sense card says it works well.