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Biohazard
06-26-2003, 03:26 AM
Is there any good sites which give you a step by step process about how to build a box? I know the dimensions(sorta) but like the exact stuff...like screw sizes and sealing process? and what not...


anywho, if i give an RE8 .75cu ft is that good? with about 140rms??

paikiah
06-26-2003, 03:31 AM
I dunno about the box size and power for the RE8's...

but as far as screws, it should be about 1" in length, so that the screw will go through 0.75" MDF.

As for sealing, make clean straight cuts, use a LOT of wood glue and when the glue dries (give it a few hours or so) use silicone (any kind, color doesn't matter ) at the seams for good measure.

I told someone to do this a long time back and it works.

When trying to smoothen silicone, apply saliva to your fingertips and work. It does wonders. Water doesn't work, saliva does.

Biohazard
06-26-2003, 03:43 AM
ahh...ok these are the types of things i would like to know! i sorta thought that but never actually seen someone come out and say it....the boxes for the RE8's are trials before the XXX :)

Biohazard
06-26-2003, 03:48 AM
how come winisd doesn't have RE subs there??

paikiah
06-26-2003, 03:57 AM
a bummer, ain't it?

search the internet for T/S parameters. The ones given are the essential numbers that winISD requires for calculations. Fill whatever you can and start seeing some amazing graph lines :)

paikiah
06-26-2003, 04:06 AM
http://www.eatel.net/~amptech/elecdisc/caraudio.htm


this place should tell you what you need to know :)

Biohazard
06-26-2003, 04:19 AM
holy crap...i am on the internet...and it never even crossed my mind to do a search....

man i am dumb....thanks paikiah u are my savior!

paikiah
06-26-2003, 04:21 AM
hey, no problem, it's what the forums are for...

besides, anyone else would've told you a similar webpage.. just that it's only 4 in the afternoon, bored as hell.. looks like i'm one of the few awake here..:)

Biohazard
06-26-2003, 04:22 AM
ahh good old loyd :)

pretty hard to find actually.....who would thing RE XXX would bring up so much ****..... yeesh

paikiah
06-26-2003, 04:24 AM
huh?? :confused:

pressed new thread instaead of new reply?

Biohazard
06-26-2003, 04:33 AM
no i found all the info in loyd's reviews..

Biohazard
06-26-2003, 05:02 AM
ok lasts question...how do u read winisd??

JeremyD
06-26-2003, 12:29 PM
This should help you get a basic understanding of begining box building...

http://www.caraudioplanet.com/forums/showthread.php?s=&threadid=4502

paikiah
06-26-2003, 12:37 PM
****, wrote one in, but got erased...****...

ok, here I go again...


I presume you know how to make a new project, change box size and port frequency ( if you don't, just open new project, select pre-entered driver, number of drivers, ported or sealed)

Once you get your graph open, try opening a competitive sub, such as the e8A.44 to make direct comparisons. A lot of veterans will tell you that graphs don't mean squat, but to a newbie whodoesn't know how to read the graphs too, it does give me a rough idea of where the subs place in the field of so many different brands and models.

Assuming you're going ported, look at how different each drivers will respond at different frequencies. It is with this that you can choose on what frequency you would like to tune your ports to.

you got to input signal strength to see SPL curves and cone excursion. I pay a lot of attention to cone excursion and rear port velocity.

multiply xmax number by 2 to get peak to peak figures, then see where the point is reached. thereabouts would be your settings for a subsonic filter.

As for rear port velocity, some say 35m/s is the max, some say 40m/s. SOme even say that 25m/s is still audible. Whatever it is, if you try to have too large a port and minimize port noise, you will have to make very long ports. SOme of it can go up to numbers like 1000"!

That said, I don't really read (or can't read) the lines much. I look more at the peaks, compared to the same driver in a sealed box, as well as a similar driver in similar sized boxes to make judgements on how large my box will have to be and what frequency I want it to peak at.

I hope that has helped out somewhat :)

evilsaint
06-26-2003, 10:27 PM
Any chance you can tell me what the "Pe" figure stands for, and if it would be screwing things up to not have it in the specs of my driver on a project? My port lengths are coming up longer than any side of the box, and i'm trying to figure out what I screwed up. This is for a slot port on a 2 cube (after displacement) single 12" box tuned to 29Hz.
Any help would be appreciated.

Biohazard
06-28-2003, 06:42 AM
change the l and w of the port..then it will come out shorter...

Mercureie
06-28-2003, 12:53 PM
just be careful u don't go too small as u will get more port noise. u can always bend the port once u get to the back of the box.

Biohazard
06-29-2003, 07:03 AM
Originally posted by Mercureie
just be careful u don't go too small as u will get more port noise. u can always bend the port once u get to the back of the box.
good thinking

evilsaint
06-29-2003, 07:43 AM
Here was what I had planned. LMK what you guys think. Common chamber box, ported to 29Hz for 2 12's. 31.5x18x15.25 ext. dimensions, and a port 2x12 that's 10inches long. Kinda like a smaller slot port. How much port noise (if any) do you think that it would make? The box, before taking out the port displacement, sub displacement, and wood width, is 5 cubes, so it'd probably be a little under 2 cubes per sub.

paikiah
06-29-2003, 08:39 AM
Originally posted by evilsaint
Here was what I had planned. LMK what you guys think. Common chamber box, ported to 29Hz for 2 12's. 31.5x18x15.25 ext. dimensions, and a port 2x12 that's 10inches long. Kinda like a smaller slot port. How much port noise (if any) do you think that it would make? The box, before taking out the port displacement, sub displacement, and wood width, is 5 cubes, so it'd probably be a little under 2 cubes per sub.

I'm guessing it's for dual 12K...

2 cubes per sub, comon chamber, so that's 4 cubes.

Port height and width 2 X 12, going for 29Hz..

I assume you're giving it around 600w RMS..




port length should be 15.1", port velocity is within acceptable limits, the loudest being 33m/[email protected] With more reasonable range of frequency, you won't be able to hear port utrbulence. :)

Hope that helps:)

burtonsnow83
06-29-2003, 10:42 AM
just checking here. How many inches should be taken off the port length in order for it to be tuned to 32 hz?

paikiah
06-29-2003, 10:58 AM
Originally posted by burtonsnow83
just checking here. How many inches should be taken off the port length in order for it to be tuned to 32 hz?

for the same specs as above?

WinISD is showing me 9.1"... shave 4" off.

Also, ssf set at about 25Hz, no less.

burton, in case you want the specs for your box, remember, if the volume changes, the length might be very different.

burtonsnow83
06-29-2003, 11:10 AM
yeah, my box dimensions are exactly the same, I think I messed something up in winisid...the only thing is with a 12x2 port do you just close the top of the port inside the box, since it doesnt go all the way to the top of the box?(hope that makes sense....

paikiah
06-29-2003, 11:15 AM
Nope, doesn't make much snese to me sorry.

COuld you rephrase that? :)

EDIT: so you mean the port ishould be shorter? You should cu out the start of the port (inside the chamber), not the exit of the ports.

burtonsnow83
06-29-2003, 11:20 AM
Originally posted by paikiah
Nope, doesn't make much snese to me sorry.

COuld you rephrase that? :)

EDIT: so you mean the port ishould be shorter? You should cu out the start of the port (inside the chamber), not the exit of the ports.

ok if I am understanding this correctly, the height of the box is 15.25 inches, and the height of the of the port is 12 inches, meaning there is 3.25 inches between the top of the port and the box(lookin gat it from the exterior) Now if you were to look inside the box, since the port walls don't go all the way to the top of the box(there are 3.25 inches left) do you cover the port?? Or do you simply make the port walls go all the way to the top and just leave a 12 inch opening in the front of the box,


if you need me to explain better I could do it in a drawing later today and send it to an e-mail

thanks

paikiah
06-29-2003, 12:14 PM
OK, so you're saying htat the port might be protruding out a bit. That's alright, but thenn your box volume will change since a bit of the port is out.
I think it'd be better if you bend the port from the insdie, rather than extending the ports to the outside.

But either way, so long as the length of the port is correct, and thevolume is unchanged(somehow), you're good to go. :)

evilsaint
06-29-2003, 02:44 PM
Paikah, how did you get a port length of 15.1"? I calculated this in WinISD, and then it checked out to be about the same on another "formulating" website. Is there are actual formula for doing slot ports, or do you just use the square port formula?

paikiah
06-29-2003, 05:19 PM
yes, of course there's a formula~ :)



I just don't bother learnibg it since I can get an answer on winISD, just like you did;)

Mercureie
06-30-2003, 01:51 AM
http://www.jlaudio.com/tutorials/ports/index.html

port formula straight from JL's website

Biohazard
06-30-2003, 04:20 AM
could someone post up a good graph for a 15" xxx?? i am still playin but i really don't know what a good graph is.....

Randy Savage
06-30-2003, 04:24 AM
Lv = (23562.5*Dv^2*Np/(Fb^2*Vb))-(k*Dv)

Dv = port diameter (cm)
Fb = tuning frequency (Hz)
Vb = net volume (litres)
Lv = length of each port (cm)
Np = number of ports
k = end correction (normally 0.732)

evilsaint
06-30-2003, 04:32 AM
Thanks nova

Randy Savage
06-30-2003, 04:36 AM
No prob ;)

paikiah
06-30-2003, 12:21 PM
good graph for SQ or SPL?

evilsaint
06-30-2003, 07:30 PM
Ok, sorry to keep bugging you paikah, but I think I figured out the final specs for my box, and I just wanted somebody to check them for me to make sure my WinISD is working correctly.

Just like before it's a 5 cube common-chamber dual-12 box w/ the 5 cubes not including wood thickness, sub displacement, or port displacment. The dimensions are 39.58Wx18Hx15.25D, and the port is 15Hx2W and is 12.63 long. This (hopefully) should be the ideal dimensions for a pseudo-slot port, as the port would actually be short enough to fit in the box from the front without bending it.

The only other question that I have is whether or not it would be okay to only have about 1inch of space between the back of the port, and the back wall of the enclosure. I don't really know if this could cause any problems. Also, how do you get the port velocity and all that in WinISD? Is that the vent Mach? I really appreciate all the help Paikah, and Snova.

paikiah
06-30-2003, 08:15 PM
Originally posted by evilsaint
Ok, sorry to keep bugging you paikah, but I think I figured out the final specs for my box, and I just wanted somebody to check them for me to make sure my WinISD is working correctly.

Sure, not a problem. ;)
I do owe you one, since I fell out of your deal...:(

Just like before it's a 5 cube common-chamber dual-12 box w/ the 5 cubes not including wood thickness, sub displacement, or port displacment. The dimensions are 39.58Wx18Hx15.25D, and the port is 15Hx2W and is 12.63 long. This (hopefully) should be the ideal dimensions for a pseudo-slot port, as the port would actually be short enough to fit in the box from the front without bending it. [/QUOTE]

Erm, thing is, I wouldn't know what kind of wood, what drivers, how your braces might look like, etc, etc... therefore, you've GOT to minus all that and give me pure volume inside after all variables...:) btw, there's no problem with bending the slot ports, you know. :)


The only other question that I have is whether or not it would be okay to only have about 1inch of space between the back of the port, and the back wall of the enclosure. I don't really know if this could cause any problems. Also, how do you get the port velocity and all that in WinISD? Is that the vent Mach? I really appreciate all the help Paikah, and Snova. [/QUOTE]

Well, I was told that the rule of thumb is to have as much space as the vent opening itself. That would mean that you need at LEAST 2" clearance. As for me, I avoid that situation by having a longer port to start with. :)

TO get port velocity, the vent Mach would be correct. If it's not in m/s, do so now. You've also got to input yout signal strength in it (RMS watts is what I use). That way, the (rear) port velocity will work. Hmmm, talking about vent mach, are you using winISD beta? Please do upgrade to winISD pro, then what I just told you would make more sense. ;)

evilsaint
06-30-2003, 10:10 PM
Okay, got a few more details for ya. I'll be using 3/4 MDF, and the final measurements that I came up with (including a true slot port) are 39.6W*18H*15.25D with a port thats 16.5H*2.5W and 19 in long. There was one thing that I was not sure about when doing the calculations for the gross interior volume: whether or not I should subtract out the 458.25 cubic inches taken out of the front plane of the box for the speaker mounting holes.

With the speaker holes' displacement subtracted, the box would be 5493.45 cubic inches, or about 3.18 cubic feet.

Without the speaker holes' displacement included, the box would be 6104.15 cubic inches, or about 3.53 cubic feet.

And for the port, the first part coming in from the front of the box will be 16.5H*11.25L, and will have 2.5" of clearance from the back of the box, while starting flush with the front. The second part will be 16.5H*7.75L, and it will run parallel(sp?) to the back board of the box, 2.5" away from it.

I sure as h3ll hope these calcs are right, because my head is about to explode from all this stupid math.... Maybe I should just build a sealed box :) With these measurements in WinISD, the graph matches the kind of frequency response that i'd like to have from these speakers; Does that mean that I shouldn't worry about the fact that ED recommends more volume inside the enclosure for a ported box?

paikiah
06-30-2003, 11:00 PM
Originally posted by evilsaint


With the speaker holes' displacement subtracted, the box would be 5493.45 cubic inches, or about 3.18 cubic feet.


Without the speaker holes' displacement included, the box would be 6104.15 cubic inches, or about 3.53 cubic feet.


Erm, I dunno how you came up with so much volume for a cutout hole... anyway, volume should be internal, so the hole diameter does not come into play. :) Only the speaker displacement will affect internal volume. :)


I sure as h3ll hope these calcs are right, because my head is about to explode from all this stupid math.... Maybe I should just build a sealed box :) With these measurements in WinISD, the graph matches the kind of frequency response that i'd like to have from these speakers; Does that mean that I shouldn't worry about the fact that ED recommends more volume inside the enclosure for a ported box? [/QUOTE]

Well, the thing is, people from ED, like Ben KNOWS the driver inside out. They also recommend the box on their site cause they know it's the best suited for daily use. If all the calculations are making you go :crazy: , then I suggest you follow the box blueprints.

But anyway, onto the calculations.


3.5cubes @??? Hz.

I'll pick up the previous post of 29Hz...

3.5cubes@29Hz (slot port 16.5X2.5)
would be 32.31"...

@35Hz would be 20.52" in length.

SOmehow, I get the feeling that this info is not what you're looking for...:(

evilsaint
07-01-2003, 12:05 AM
Maybe i'm doing the WinISD thing wrong, but i've double checked all the units and the TS specs.

Start a new project, put in the TS specs for the EDK 12. Select 2 drivers, normal placement, vented box. Put in 5 cubes in the box, and 29Hz tuning. Click box shape, put in wood thickness (.75), put in H(18) and D(15.25), then click on W to have WinISD make it automatically(39.6) because I have height and depth restrictions in my setup, but not width. Click vent shape to be square, type in diameter (16.5x2.5), and length of 19 shows up......

What am I screwing up?

Also, on that 3.5Cube at 29z estimate you did, was the wood thickness set, because if it was, doesn't WinISD automatically subtract the wood thickness? If it did, the gross volume would be a lot smaller than 3.5cubes...

paikiah
07-01-2003, 01:01 AM
Ah, so there's the problem...

you're using winISD, not winISD pro...

btw, you might want to retype all the specs on it. It's not really that accurate. :)

EDIT: I've always put in NET volume for box, not GROSS. :) Maybe I'm the one doing it wrong, but it seems to work well with NET.

Now, if it was gross instead of net, I'd be doing :banghead: for the next 2 hours so don't expect a reply anytime soon..:P

evilsaint
07-01-2003, 09:48 AM
Paikah, you seem to be having much better luck with this stuff than I do, so i'd really appreciate it if you could tell me the full specs on a box that you would recommend for these subs either from personal preference, experience, whatever. As long as it's vented, tuned more for SQ than SPL, no higher than 18in, and no deeper than 15.25, it'll work for me. I understand if you won't do this for me, but if you can, please do so. I installed WinISD Pro and even coming from a guy who does computer networking, that program has a LOT of settings...... :eek: Thanks again. And 'grats on getting to 4k posts :D I'm a tenth of the way there....

paikiah
07-01-2003, 10:45 AM
Originally posted by evilsaint
Paikah, you seem to be having much better luck with this stuff than I do, so i'd really appreciate it if you could tell me the full specs on a box that you would recommend for these subs either from personal preference, experience, whatever. As long as it's vented, tuned more for SQ than SPL, no higher than 18in, and no deeper than 15.25, it'll work for me. I understand if you won't do this for me, but if you can, please do so. I installed WinISD Pro and even coming from a guy who does computer networking, that program has a LOT of settings...... :eek: Thanks again. And 'grats on getting to 4k posts :D I'm a tenth of the way there....

Hey, I didn't even realise that I eached 4000...:p
Well, I've not heard any adire, RE or ED subs...yet. I won't be able to tell you the exact details to it. A person that taught me a lot about box building was Jmac. You could just tell him the exterior dimension of the box, what driver, and he would be able to tell you what volume and port tuning you should have. The actual calculations (dimensions) will have to be calculated by you. It's an irritatingly long ns slow process (to me, at least) so sometimes it might be better to build backwards. Imagine a box with so and so volume, and what port. Calculate that and work backwards. It seems to take me loner somewhat, but it gets the job done, as I understand it. :)

Then again, as a general rule of thumb, I think people who wants SQ in thier ported box do not go over 35Hz... usually 30Hz and below.

You should mention what limit your length is.

The subs were for dual 12K's right? For Sq, I say you don't need to go large at all...2.5~3 cubes, ported to about 27~30Hz. Run winISD pro, look at the frequency response. Open one with a ported box, another one without. That will allow you to compare response between the two. So long as you avoid peaks in the line, you've gpt yourself a ported box good enough to be called an SQ box. :)

Biohazard
07-03-2003, 03:29 AM
Originally posted by paikiah
good graph for SQ or SPL?
a bit more spl.....about 65/35=spl/sq

paikiah
07-03-2003, 03:38 AM
SPL would have a bump somewhere, a peak of some sort. THe higher the angle, the more SPL oriented it is.

Similarly, as you might have noticed from sealed boxes, SQ would have a smooth line. :)