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SubsonicSounds
06-23-2008, 01:32 AM
First post, so hello to all.

I am thinking about getting a new sealed enclosure for a single 10 inch Alpine Type R. My goals for this enclosure are based on my personal tastes in the total sound experience, which are probably different from many.

I listen to many types of music, but the most important genre to me for the purpose of this project is bass music. I have been listening to bass on a variety of different setups since the days of techmaster p.e.b.

Before describing what i am trying to accomplish, let me start by explaining that I understand I am not using what many would consider the optimal driver for obtaining very low frequencies such as those below 20Hz. I understand the limitations of cone area and the direct relationship between that and movement of air. However, I am still attempting to meet my goal so...

What I am trying to accomplish from this enclosure:
1. Having something unique that suits my personal interests.
2. Using the 10 inch Type R driver in a sealed enclosure.
3. Tuning in the lowest of frequencies as much as possible. I love the lowest note on Bass I Love You, and actually can hear it decently well with my current box, with the left-side back seat in the down position. I do want more if possible.
4. Audio system is commonly used with engine off, windows cracked for best frequency response. I do not necessarily listen to this system very loud, although I am still getting alot of rattling inside the cabin.

Here is what I came up with.
1. Large box to allow the most unrestricted cone excursion, therefore propogating the cleanest possible low frequency sound waves for this sub..

External Dimensions:

H - 13.0 in
W - 15.0 in
L - 24.0 in

Assuming 3/4 inch MDF, that would give me approx 2.8 cubic feet if i calculated right.

Please post a response telling me what you think, and if there is anything I should know about accomplishing this goal of trying to go as low as possible. Am I on the right track or am I somewhere out in left field wandering aimlessly.



Thanks in advance.

NissanKicker
06-23-2008, 01:51 AM
Just to put you up on game...
... There is NO tuning for a sealed enclosure.

Only thing you can do with a sealed enclosure for that sub is make it around 1.5cuft and include about 50% polyfill.
... or go with a ported enclosure tuned @ 40hz ( 38hz at the lowest )

SubsonicSounds
06-23-2008, 02:27 AM
Thank you for taking the time to respond, and perhaps you are correct.

But... once again everything i understand about physics and the laws of motion suggest that the volume of air behind a subwoofer would change quite a few parameters that would directly effect the overall performance characteristics of the driver.

My main concern would be air pressure behind the subwoofer. When the speaker is moving quickly at higher frequencies, higher pressure behind would seemingly assist the cone in returning to its point of origin, which is good when trying to oscilate a reasonably massive object very rapidly.

I however, am going to need some extra excursion, (remember, I am going for 25hz and below) causing a need for the cone to move more freely without overloading the the electromagnetic system.

I am hoping for some more responses to help verify what i am trying to do.

SubsonicSounds
06-23-2008, 02:31 AM
I do agree on the polyfill, as I believe reflected sound waves will cause the unwanted cone movement, so that is a definite go!

NissanKicker
06-23-2008, 02:33 AM
Well... First off... 25hz w/ a 10" Type ARRHHHH ????? That's goin' to be a VERY faint note.
2nd: you're not goin' to achieve more excursion in a sealed box.
* Being sealed = tighter bass, stiffer sub... It doesn't give your sub any time to move. ( Like you're wanting it to )
3rd: you need a ported enclosure...

tez4life
06-23-2008, 02:33 AM
My personally suggestion is to consider another sub. The Type R 10" doesnt sound like its going to cut it for your desire for subsonics. Are you dead set on that sub?

GLN305
06-23-2008, 02:41 AM
You want to be careful about putting that 10" in such a large enclosure. The air inside the box acts as a restoring force (hence the term acoustic suspension) and if you have too much air to compress then you lose that restoring force. My recommendation for you is to download WinISD, learn to use it and play with enclosure designs. You are probably going to be pointed in the direction of a low tuned ported enclosure. This will emphasize the very lows ( I like them too). Good luck!

NissanKicker
06-23-2008, 03:13 AM
This is what you need
... 2.08cuft Overall - tuned @ 38hz.
http://i214.photobucket.com/albums/cc75/NissanKicker/110ported_FullScreen.jpg

20"W x 15"D x 12"H

SubsonicSounds
06-23-2008, 03:14 AM
Nissan, I have just done some quick research. I believe I am correct with my theory on internal volume affecting cone backpressure during excursion, and subsequently the overall frequency response curve of the subwoofer. (If we consider the JL Audio website scientifically sound.) While I will agree with you that there is "less" tuning involved with a sealed enclosure, there is still "some" tuning that can be done, and can be compounded by greater differences in air volume behind the cone. See: infinite baffle.

Also, I would absolutely love to do a ported enclosure guys, but once again, I am really trying to reproduce these low frequencies. Im dealing with very long wavelengths, and to be honest, it would be difficult to create an enclosure that would house vents equaling the quarter lengths of these waves.

To be honest, I would love to try a transmission line box, but I lack the woodworking skill/tooling to do so, and I really do not know where to go or who to approach on that one.

And yes, I did mention above that what I trying to do with what I have is challenging/counterintuitive, but maybe what I learn from this can later to be applied to "bigger" and "badder" subwoofers. I guess you could say I am starting out on a small scale.

That said - low frequency pwns.

NissanKicker
06-23-2008, 03:30 AM
Like I said you my previous post... That what you need.
... If you see different ( which I'm getting that you do ), I don't know.. But Good Luck!

SubsonicSounds
06-23-2008, 03:30 AM
This is what you need
... 2.08cuft Overall - tuned @ 38hz.
http://i214.photobucket.com/albums/cc75/NissanKicker/110ported_FullScreen.jpg

20"W x 15"D x 12"H

38 Hz? AAAAAAAAAgggggggggghhhhhhhhhh! I need LOW!

Ok. Let me see how I can let you know how I like the bass...

Ever throw in a Bass Mekanik CD? You know the really low notes. Many setups won't even hit it. Maybe they have subsonic filters. Maybe ports are tuned high and allow low frequency cancellation.

My setup is can not be like that. I like the bass that seems to undulate. The type of bass that shakes your eardrums back and forth more slowly. The ones that feel like an earthquake has just originated from your trunk... I want the lowest notes! I do care about spl, but not at standard competition frequencies. I care about it at 20hz and thereabouts.

NissanKicker
06-23-2008, 03:39 AM
a single Type R 10" sub isn't goin' to give you what you want. Sorry. Look @ a DD9910z ...

SubsonicSounds
06-23-2008, 04:12 AM
a single Type R 10" sub isn't goin' to give you what you want. Sorry. Look @ a DD9910z ...

LOL, I'm not going there.

Once agian, thanks for your input, but don't forget this is purely an experiment. Please don't think that I have the pretense that I am going to attempt to shake windows in drive thrus. I am being realistic in my test setup. I have had louder setups that were probably much more impressive to others. Weren't we all "cool" in high school?:cool:

This is different.

I don't think I care about the cool factor in any way anymore. I want to better understand how what we are all doing here works. And to begin with, I am trying to learn how to reproduce sound waves in a purely scientific manner under "relatively" real life conditions with intentional limits.

Would it be easier with larger and more subwoofers? Well obviously. Will that help me understand how to better reproduce low frequencies with the current technology at my fingertips? I doubt it.

Could my findings help apply what I have learned on a larger scale in the future? Maybe.

Will I have fun finding out? Absolutely. So please understand that your efforts in trying to discourage me from using the Type "Arrghhh" as you call it, will be entirely futile.

SubsonicSounds
06-23-2008, 04:21 AM
You want to be careful about putting that 10" in such a large enclosure. The air inside the box acts as a restoring force (hence the term acoustic suspension) and if you have too much air to compress then you lose that restoring force. My recommendation for you is to download WinISD, learn to use it and play with enclosure designs. You are probably going to be pointed in the direction of a low tuned ported enclosure. This will emphasize the very lows ( I like them too). Good luck!

Thanks for you honest concern guys.:) And yes Tez, I am seemingly dead set on using this sub. (See reason in my last post). I realize that there are some limits, and the bar is not set very high. However, it is not permanent, as I will undoubtedly suffer from the "its never enough" syndrome and apply what I have learned to bigger and better things.

GLN - I certainly will try the software that you suggested. I have actually worked with some lesser versions of enclosure software, and have learned a few things already. Very valuable stuff.

NissanKicker
06-23-2008, 04:31 AM
I'm not telling you not to use the type r... I'm just simply stating.. go ported.

... I calculated...
(1) 10" Alpine Type R in a 20cuft. enclosure SEALED ( WOW! )... would be 30.88hz capable.
... Have fun with that.

* 666 post ... That's not a good number *

Witty690
06-23-2008, 04:34 AM
Everything you want, you will get with a low tuned ported enclosure.

Sealed wont cut it, but i wish you luck anyway.

SubsonicSounds
06-23-2008, 04:50 AM
I'm not telling you not to use the type r... I'm just simply stating.. go ported.

... I calculated...
(1) 10" Alpine Type R in a 20cuft. enclosure SEALED ( WOW! )... would be 30.88hz capable.
... Have fun with that.

* 666 post ... That's not a good number *

I think you are trying to get me a resonant frequency. Resonant frequency is more important in a vented enclosure, as the port lenght causes an inherent steep roll off below that frequency. Out of phase sound wave cancellation is a killer.:p:

Don't let that above number mislead you. I promise that in my current sealed 1.06 cubic ft. enclosure, I can produce enough sound pressure at 18Hz to make it clearly noticeable. I have had 20Hz prompt people to say, "what the heck?" But outside of getting a meter right now at 3am, I cannot make you see that these frequencies are possible from this sub. Granted they are not loud, it is enough to make trunk panels move.

You may still be thinking that this is minimal sound, and compared to your system, im sure it is. But getting the bass to extend low is interesting to say the least.

SubsonicSounds
06-23-2008, 05:10 AM
Everything you want, you will get with a low tuned ported enclosure.

Sealed wont cut it, but i wish you luck anyway.

I agree with you on the first part. However, in creating a very low tuned vented enclosure, you need to create a vent that is long enough to support the incredibly long wavelengths (that I am for some strange reason going for), by keeping "out of phase waves" from the rear of the speaker from negatively interacting with the "in phase" waves coming from the front.

From my understanding, this is only done by allowing enough time to pass for the "in phase" wave eminating from the front of the speaker to oscilate and become better aligned with the wave coming from the port.

The only way to do this that I can presently concieve of is to create a vent long enough for these long wavefronts to better align themselves, i.e. T-line.

I can see how certain types of more conventional ports could increase internal air pressure by restricting the flow of molecules, thus creating a higher velocity, and shortening the time elapse requirements of the rear-of-cone wave front. But I believe that this would add a variable that might be incredibly difficult to analyze by increasing back pressure on the cone. Anyone well versed in fluid dynamics?

Rashaddd
06-23-2008, 06:35 AM
OP, go with a sealed box.

1. its clearly what you want, so just do it, its easier to mess with anyway than a ported one. You can even build a big one and fill it with solid objects to adjust box size and figure out what kind of differences in freq response you get depending on box size

2. I'm pretty sure I know what you're talkin about with the low "earthquake" type feeling you get from 15hz-25hz, and it seriously can be sick

3. Yes he can get a ported enclosure, but its not going to do what he's looking for very efficiently unless he tunes it to ~20hz

4. I was able to get some serious lows (20-30hz) with a couple sony xplods in just 1.15 cubes each sealed...I'm sure you can do it with some nicer subs, but seriously...just buy an mj 18 or a cheap 15 or somethin. I don't see any reason to attempt it with a single not-so-great 10" sub...thats like trying to use a bicycle to break the world record for land speed. You might as well start with an advantage at least.

(video of some of the lows ur talkin about with my old xplods, now sold and gone) (http://youtube.com/watch?v=u4UByXahezo)

helotaxi
06-23-2008, 06:50 AM
I agree with you on the first part. However, in creating a very low tuned vented enclosure, you need to create a vent that is long enough to support the incredibly long wavelengths (that I am for some strange reason going for), by keeping "out of phase waves" from the rear of the speaker from negatively interacting with the "in phase" waves coming from the front.

From my understanding, this is only done by allowing enough time to pass for the "in phase" wave eminating from the front of the speaker to oscilate and become better aligned with the wave coming from the port.

The only way to do this that I can presently concieve of is to create a vent long enough for these long wavefronts to better align themselves, i.e. T-line.

I can see how certain types of more conventional ports could increase internal air pressure by restricting the flow of molecules, thus creating a higher velocity, and shortening the time elapse requirements of the rear-of-cone wave front. But I believe that this would add a variable that might be incredibly difficult to analyze by increasing back pressure on the cone. Anyone well versed in fluid dynamics?

You are only partially getting how a ported enclosure works. There is no reason to consider a T-line or any 1/4 wave design. The resistance of the port and the effect of that resistance from a given area and length relative to a given enclosure volume is very predictable and well modeled by the standard enclosure calculations. But I still agree with you that a sealed enclosure is the way to go for the really low stuff.

NissanKicker obviously has no idea what you're talking about, nor how to properly model a sub system for use in a car. He seems to not understand the effects of cabin gain and why an F3 of 50hz in no way keeps the system from reproducing frequencies well below that with authority from a sealed system while the same cannot be said about most ported setups below tuning.

Since you really just want to hear the low stuff and not really be abused by it, a decent sized sealed box with moderate power should get you where you want to be or at least as close as you'll get with that sub. More cone are or excursion capability or both would help you out a lot towards your goal, though.

Really like the choice of music. I listen to everything (almost) as well and I really like Techmaster P.E.B. and have for years.

Krown
06-23-2008, 07:06 AM
Don't forget that using enough polyfil will basically "enlarge" the enclosure.

NissanKicker
06-23-2008, 11:55 AM
Helotaxi:
... for one... I do know what he's talkin' about and tryin' to accomplish.
Quote:
" I don't see any reason to attempt it with a single not-so-great 10" sub...thats like trying to use a bicycle to break the world record for land speed. You might as well start with an advantage at least. "

BINGO! - the note to going to be faint. only thing that was mentioned was, I wanna hit the LOWS!.... earthquaking effect bass... go ported... Easiest way.

NOW!
... As far as a sealed hitting lows, that's no doubt. sealed has a fuller range on music OVER port-tuned enclosures. I had 4 cvx 12s and you felt 15hz like a 30hz note. I'm not denyin' nor taken anything away from a sealed enclosure nor his ideas. I'm just simply stating " if you feel it can be done, do it. I showed him the enclosure needed... If not, I'll tune it to 20hz ( for a 10... I don't know why but ok ).

As for as a T-line box, there's no need and I don't have to speak on that ( that's been taking care of - Helotaxi )... ALL & ALL, there's a simpler way to do it. But as you stated - Just for knowledge and a better understanding.

GoodLuck Bro.

SubsonicSounds
06-23-2008, 01:35 PM
You are only partially getting how a ported enclosure works. There is no reason to consider a T-line or any 1/4 wave design. The resistance of the port and the effect of that resistance from a given area and length relative to a given enclosure volume is very predictable and well modeled by the standard enclosure calculations. But I still agree with you that a sealed enclosure is the way to go for the really low stuff.

You are absolutely correct. I think i am only partially understanding how a ported enclosure works (i do mean in relative terms). That is one of the reasons why at this point I am opting to avoid the ported enclosure. I'm somewhat concerned with the effects on the waves during the compression and subsequent decompression processes through the restrictive points encountered while exiting the enclosure. I know that there is research out there, and I know that many on this forum can help me understand, but that is for another day. I'm hoping to go that direction after I have a sealed setup completely figured out.



Really like the choice of music. I listen to everything (almost) as well and I really like Techmaster P.E.B. and have for years.

P.E.B. was a talented composer, with unmatched mixing abilities for his time. Some of his work was capable of putting me in a dreamlike state LOL.

Nissan, I do believe that you understand what I am interested in accomplishing, and I thank you for wishing me luck. I think it will be needed in finding someone to construct my enclosure around here where I live. :)

helotaxi
06-23-2008, 03:24 PM
Helotaxi:
... for one... I do know what he's talkin' about and tryin' to accomplish.

If you're recommending a ported box tuned to the high 30's, ummm, no, you obviously don't. Even Alpine recommends a lower tuning, and my experience has shown the manufacturer spec enclosures are usually a little small and tuned a little high. Better SPL, which is what most people want. Tuning higher than that is only going to make the response peak bigger and steepen the rolloff below that. The effect would be to cut the lows even more, which is definitely not what he was looking for.

There's no reason that sub shouldn't be able to go well below the audible spectrum in-car in a sealed box. It isn't going to really take your breathe away because it's still just a 10, but it'll still ba able to get down there. Cabin gain will help it out a lot in that regard. Pretty much any sub will be able to go below the audible range sealed in a car.

BEAVER.989
06-23-2008, 03:40 PM
I also recommend a low tuned ported enclosure. The problem with building a larger sealed box with q approaching .5 is that you'll quickly run out of excursion while trying to reproduce the lowest octaves.

With a ported enclosure excursion is significantly reduced near the tuning frequency which allows you to apply more power. This, along with the increased efficiency of the ported design is going to best accomplish what you're after, IMO.

SubsonicSounds
06-23-2008, 04:11 PM
... Even Alpine recommends a lower tuning, and my experience has shown the manufacturer spec enclosures are usually a little small and tuned a little high. Better SPL, which is what most people want. Tuning higher than that is only going to make the response peak bigger and steepen the rolloff below that. The effect would be to cut the lows even more, which is definitely not what he was looking for.

There's no reason that sub shouldn't be able to go well below the audible spectrum in-car in a sealed box. It isn't going to really take your breathe away because it's still just a 10, but it'll still ba able to get down there. Cabin gain will help it out a lot in that regard. Pretty much any sub will be able to go below the audible range sealed in a car.


You have seemingly pinpointed exactly what i am trying to accomplish and why I would attempt it. I thank you for taking the time to evaluate what I am attempting, and acknowledging it pheasability. I agree with your theory on manufacturer recommendations. The are most likely trying to "impress" the customer, rather than prompting the flattest possible frequency response without rolloff.

SubsonicSounds
06-23-2008, 04:15 PM
***New Question*** In a rectangular enclosure, is there a problem mounting the driver closer to one end of the enclosure, or does it need to be centered to eliminate uneven pressure on the back of the speaker? In other words, will I cause unwanted damage or distortion by having the speaker close to one end of the enclosure?

BEAVER.989
06-23-2008, 04:17 PM
I recommend that you download WinISD (it's free) and model the sub in a variety of enclosures to see for yourself exactly what you can expect to get out of a given enclosure.

BEAVER.989
06-23-2008, 04:24 PM
***New Question*** In a rectangular enclosure, is there a problem mounting the driver closer to one end of the enclosure, or does it need to be centered to eliminate uneven pressure on the back of the speaker? In other words, will I cause unwanted damage or distortion by having the speaker close to one end of the enclosure?

Stuff the sub all the way to one side. How else are you going to have enough room for that port? ;)

Seriously, it won't hurt anything to do it that way... even if it's sealed.

SubsonicSounds
06-23-2008, 04:29 PM
I'm not doing the ported. Im actually doing the sealed, and my current drawing has it all the way to one side for better in vehicle location. However, it seems that on the rear of the cone (the part exposed to the inside of the box), the side that is close to the side of the box will not recieve as much reflected wave energy as the side that is more open to the bulk of the enclosure.

Im afraid this may cause lateral movement of the cone, which would cause voice coil deflection, and therefore causing a decrease in motor efficiency, and possibly some rubbing issues between the voice coil and magnet. It would be like putting your hand on one side of your cone and pushing it back. The uneven push causes lateral movement that causes an audible scratching sound between your v.c. and magnet. This is damaging the coil, and if the speaker were playing, temporarily destroying the overall geometry of the motor structure.

I have already ordered the box, so i guess im just hoping that I am wrong.

Maybe the air inside the box will do its job of equalizing in air pressure causing a balanced push from all directions. Yes/No?

Maybe the pressure will be low enough not to significantly effect cone movement.

Maybe I think too much. Anyone in the know?

Buck
06-23-2008, 04:31 PM
ported. end of discussion

BEAVER.989
06-23-2008, 04:33 PM
I'm not doing the ported. Im actually doing the sealed, and my current drawing has it all the way to one side for better in vehicle location. However, it seems that on the rear of the cone (the part exposed to the inside of the box), the side that is close to the side of the box will not recieve as much reflected wave energy as the side that is more open to the bulk of the enclosure.

If that were a valid concern home audio speakers would place the woofer in the center of the cabinet instead of the very bottom...

I think you're overthinking things, man... nothing wrong with that, though. I am much the same.

SubsonicSounds
06-23-2008, 04:59 PM
If that were a valid concern home audio speakers would place the woofer in the center of the cabinet instead of the very bottom...

I think you're overthinking things, man... nothing wrong with that, though. I am much the same.

Thought the EXACT same thing, but once again began thinking about it, and I believe that most of the "tower" type home enclosures that you are speaking of are chambered, which would creat a small enclosure at the bottom where the speaker would actually be centered.

BEAVER.989
06-23-2008, 05:03 PM
some are chambered, some are not. you have nothing to worry about.

SubsonicSounds
06-23-2008, 05:06 PM
ported. end of discussion

Oh, man. Thanks. I think im just going to go back to bed and sleep knowing that my problems are all so simply solved. And to think guys, all this could have ended with 4 words. LOL.

If you read above, someone suggested that. But I think most would agree that it was certainly not the end of the discussion.

To be fair...

I do know that a vented enclosure will be the optimum type for this ASSUMING a relatively ideal enclosure design, but I think we have established that creating a relatively ideal vented design for my tastes would be very time consuming, and would take up a great deal of space to house the required length tubes for my tuning frequencies without creating wave distortion through the compression/decompression process.

BEAVER.989
06-23-2008, 05:12 PM
I'm not going to try to twist your arm, but I really believe the ported solution is best, as well.

If it's just the matter of designing the enclosure that's holding you back, speak up. I'll be more than happy to model up a design for you in WinISD, if you'd like.

Ultimately, it's your decision, though. If you're more comfortable with a sealed design, then stick with it. I wish you luck in whatever you decide to do.

SubsonicSounds
06-23-2008, 05:18 PM
some are chambered, some are not. you have nothing to worry about.

I can speculate that the air pressure effects that I am worried about could be negligible considering the overall internal volume of the enclosure. I can see how the situation that i am worried about would be no different than the effects of speaker location relative to panels of the cars interior in some cases with trunk mounted subwoofers.

You might be right. Thank you for the insight.:)

SubsonicSounds
06-23-2008, 05:21 PM
I'm not going to try to twist your arm, but I really believe the ported solution is best, as well.

If it's just the matter of designing the enclosure that's holding you back, speak up. I'll be more than happy to model up a design for you in WinISD, if you'd like.

Ultimately, it's your decision, though. If you're more comfortable with a sealed design, then stick with it. I wish you luck in whatever you decide to do.

I may actually ask you for some help in the near future. I do need to finish this project first. The good news is if I eventaully design a vented enclosure (leaning towards T-Line), I have a 10 inch type-e as well that can be used in whatever box I do not decide to keep. Just throw that in the closed and connect it to a home amp.

NissanKicker
06-23-2008, 06:19 PM
Why don't you just cut into your reak deck ( Like an IB setup )... And seal off the trunk.
... Kind of like how Lexus does their rear stage ( 10" sub in rear deck only ).

miker
06-23-2008, 06:25 PM
How about, you make a sealed AND ported box..

Now thats an idea..

SubsonicSounds
06-23-2008, 06:40 PM
Why don't you just cut into your reak deck ( Like an IB setup )... And seal off the trunk.
... Kind of like how Lexus does their rear stage ( 10" sub in rear deck only ).

Actually, that would be a good possibility with potentially superior results. This way of baffling the sub would provide an enourmous amount of effective box volume behind the cone. I would without a doubt be losing a significant amount of power handling, as the air reflex effect would be very low, allowing for more unrestricted cone movement, eventually reaching the limits of excursion. I will have to see how my sub performs in the box that I designed (should have it by Friday), to see how much of a factor the electromechanical limits of the suwoofer design will be.

The rear stage infinite baffle design has two inherent advantages that immediately come to mind.

1. The sound waves are reflecting directy from the rear window towards the front of the car, possibly producing low frequencies with better sound imaging for the front seat listener.

2. The air pressure restrictions behind the cone will be very limited, which could be advantageous for low frequency propogation in the way mentioned above.

Ever heard a well amplified pair of 6x9's mounted in the stock location? Some can hit pretty low!

Disadvantage:
However, in my current plans, with the sub front face playing into the trunk, with one seat down, I am effectively using the trunk as a source of interior gain.

Nonetheless....

Good call Nissan. Btw, since you seem to know about some specific applications of IB subs in factory installations, don't be afraid to post links! Don't think for a minute that I wont read them.

SubsonicSounds
06-23-2008, 06:45 PM
How about, you make a sealed AND ported box..

Now thats an idea..

Do you mean utilizing sealed and ported technology at the same time in some type of bandpass, or do you mean actually making two seperate boxes? I have metioned experimenting with both types of enclosure and probably will.

miker
06-23-2008, 06:47 PM
Do you mean utilizing sealed and ported technology at the same time in some type of bandpass, or do you mean actually making two seperate boxes? I have metioned experimenting with both types of enclosure and probably will.

I mean experimenting with both kinds,

Sorry I just read the first page and part of the last, and that was all I could think, since it's not even a large enclosure trying a couple boxes won't take too much time or cost too much.

SubsonicSounds
06-23-2008, 06:50 PM
I agree, and as I said, I still can utilize both boxes regardless of the outcome.

helotaxi
06-24-2008, 09:38 AM
***New Question*** In a rectangular enclosure, is there a problem mounting the driver closer to one end of the enclosure, or does it need to be centered to eliminate uneven pressure on the back of the speaker? In other words, will I cause unwanted damage or distortion by having the speaker close to one end of the enclosure?

At sub bass frequencies, there are no "inbox reflections" or anything of that sort to worry about. There are no "waves" inside the box at all. The frequencies in question have a 20+ ft wavelength. The air inside the box simply pressurizes as a whole and rarifies as a whole as the cone moves. You're thinking WAY to much about this and assuming that concerns exist where ther are none.

You could build an extremely low tuned ported enclsure and accomplish whatyou want but it will have 2 characteristics that will be detrimental to your goal. First it will have to be HUGE. Second the port will have to be HUGE making the gross size of the box that much bigger. To be playing the freqs that you're looking for, you're looking at a tuning of 20hz, probably lower. Power handling will not be any better than with a large sealed box because the enclosure would have to be very large to keep the output around tuning from being suppressed below what you would get from a large sealed enclosure at that frequency. Yes, that's what happens when you put a sub in a ported enclosure tuned much lower than it wants to be tuned, output actually drops (which kinda defeats the purpose to going ported in the first place). You have to make the box HUGE to boost that low output shelf back to somewhat normal levels. You can't get around Hoffman's Iron Law, even with a ported enclosure. You can have efficiency, low frequency extension and a small box, pick two.

SubsonicSounds
06-24-2008, 07:53 PM
I have decided to go a different direction with this enclosure design. I am not going to disclose any information yet other than saying that I am confident that my original expectations will be exceeded. I will also say that I have discussed my plans with the right people.

I will do my best to document performance when the enclosure is complete. Thanks to all that offered input. You have prompted me to investigate more deeply into this endeavor, which has opened up a few doors that I did not know existed.

BEAVER.989
06-24-2008, 09:00 PM
I have decided to go a different direction with this enclosure design. I am not going to disclose any information yet other than saying that I am confident that my original expectations will be exceeded. I will also say that I have discussed my plans with the right people.

I will do my best to document performance when the enclosure is complete. Thanks to all that offered input. You have prompted me to investigate more deeply into this endeavor, which has opened up a few doors that I did not know existed.

Oh no, he's going to a PR set-up. ;)

PV Audio
06-24-2008, 11:31 PM
Well... First off... 25hz w/ a 10" Type ARRHHHH ????? That's goin' to be a VERY faint note.
2nd: you're not goin' to achieve more excursion in a sealed box.
* Being sealed = tighter bass, stiffer sub... It doesn't give your sub any time to move. ( Like you're wanting it to )
3rd: you need a ported enclosure...
You really don't know what you're talking about, do you?

PV Audio
06-24-2008, 11:38 PM
Subsonic, what do you do for a living? You seem to have a solid knowledge of wave and acoustic vibrations theory, but they don't apply here. As an engineering student, I'll let you know that what you learn in the classroom doesn't really apply to car audio half as much as it does for home audio. This is why you design enclosures entirely different depending on the architecture surrounding the system. If you're not set, listen to helotaxi; he's smart as **** with this **** and I learned a lot from him before he vanished a few years ago :D

NissanKicker
06-25-2008, 12:52 AM
I don't know what I'm takin' about????
... That's funny.

SubsonicSounds
06-25-2008, 01:01 AM
Oh no, he's going to a PR set-up. ;)

Not sure what you are referring to. What do you mean by "PR"?

SubsonicSounds
06-25-2008, 01:30 AM
Subsonic, what do you do for a living? You seem to have a solid knowledge of wave and acoustic vibrations theory, but they don't apply here. As an engineering student, I'll let you know that what you learn in the classroom doesn't really apply to car audio half as much as it does for home audio. This is why you design enclosures entirely different depending on the architecture surrounding the system. If you're not set, listen to helotaxi; he's smart as **** with this **** and I learned a lot from him before he vanished a few years ago :D

I absolutely agree with your comments on automotive interior architecture, there are endless variables that affect the propogation and transmission of wave energy throughout the vehicle, further compounded by even the very dynamic nature of the vehicles many possible geometrical configurations. This "listening room" (to compare what is being done to a home audio setup) that we are trying to create changes inherently everytime a window is adjusted, a sunroof is opened, a seat position is changed, and profoundly as the barometric pressure fluctuates.

I also agree that while extensive knowledge of physics allows an enthusiast to better understand the results of actual experimentation within our "labs" (vehicles), one cannot possibly fully predict the behavior of drivers, and the waves that they produce in any vehicle. Prior knowledge of science helps us plan, but new, further understanding of science (through the learning that takes place prompted by data gathered from experimentation) is what allows us to move forward and make improvements.

One more quick comment. (PV this part is not directed at you) Although I am new here, I would like present one idea. Instead of offering a purely negative feedback, or feedback that is overly simplified and in absence of sufficient explanation, try offering a comment that is well grounded in some type of research, or honest and accurate prior knowledge that has been tested sufficiently, rather than a resonse driven by sarcasm or satire or the likes of. I would speculate that the amount of learning that takes place in this forum would increase. I just want to understand the most possible, and hopefully help others do so as well in the future. For reference, this thread has not been a problem, and has been very helpful as stated above.

Just my personal insight. Take it as you wish, for whatever its worth.

Thanks again for all of the input.

TurdFergueson2
06-25-2008, 01:34 AM
I absolutely agree with your comments on automotive interior architecture, there are endless variables that affect the propogation and transmission of wave energy throughout the vehicle, further compounded by even the very dynamic nature of the vehicles many possible geometrical configurations. This "listening room" (to compare what is being done to a home audio setup) that we are trying to create changes inherently everytime a window is adjusted, a sunroof is opened, a seat position is changed, and profoundly as the barometric pressure fluctuates.

I also agree that while extensive knowledge of physics allows an enthusiast to better understand the results of actual experimentation within our "labs" (vehicles), one cannot possibly fully predict the behavior of drivers, and the waves that they produce in any vehicle. Prior knowledge of science helps us plan, but new, further understanding of science (through the learning that takes place prompted by data gathered from experimentation) is what allows us to move forward and make improvements.

One more comment. Although I am new here, I would like present one idea. Instead of offering a purely negative feedback to comments that have been made in a thread, try offering a comment that is well grounded in some type of research, or honest and accurate prior knowledge that has been tested sufficiently, rather than a resonse driven by sarcasm or satire or the likes of. I would speculate that the amount of learning that takes place in this forum would increase. I just want to understand the most possible, and hopefully help others do so as well in the future.

Thanks again for all of the input.

Words..........lol

PV Audio
06-25-2008, 01:59 AM
I don't know what I'm takin' about????
... That's funny.I'm glad you have a sense of humor, because I personally don't find someone wanting deep bass being told to tune to 40hz and then spouting acoustical fallacies to be humorous.

PV Audio
06-25-2008, 02:00 AM
Oh, you're that trunk wars guy. Got it now.

PV Audio
06-25-2008, 02:01 AM
I absolutely agree with your comments on automotive interior architecture, there are endless variables that affect the propogation and transmission of wave energy throughout the vehicle, further compounded by even the very dynamic nature of the vehicles many possible geometrical configurations. This "listening room" (to compare what is being done to a home audio setup) that we are trying to create changes inherently everytime a window is adjusted, a sunroof is opened, a seat position is changed, and profoundly as the barometric pressure fluctuates.

I also agree that while extensive knowledge of physics allows an enthusiast to better understand the results of actual experimentation within our "labs" (vehicles), one cannot possibly fully predict the behavior of drivers, and the waves that they produce in any vehicle. Prior knowledge of science helps us plan, but new, further understanding of science (through the learning that takes place prompted by data gathered from experimentation) is what allows us to move forward and make improvements.

One more quick comment. (PV this part is not directed at you) Although I am new here, I would like present one idea. Instead of offering a purely negative feedback, or feedback that is overly simplified and in absence of sufficient explanation, try offering a comment that is well grounded in some type of research, or honest and accurate prior knowledge that has been tested sufficiently, rather than a resonse driven by sarcasm or satire or the likes of. I would speculate that the amount of learning that takes place in this forum would increase. I just want to understand the most possible, and hopefully help others do so as well in the future. For reference, this thread has not been a problem, and has been very helpful as stated above.

Just my personal insight. Take it as you wish, for whatever its worth.

Thanks again for all of the input.Just to let you know, your writing style is far above the average CA.com er's reading level :laugh:

SubsonicSounds
06-25-2008, 04:19 AM
Just to let you know, your writing style is far above the average CA.com er's reading level :laugh:

I write in a highly technical fashion in order to avoid any ambiguity in reader perception of my statements. I think it is approiate for the desired level of technicality in the discourse of this particular thread.

While I do understand that writing may seem shifted towards the advanced end of the spectrum, I certainly do not think that the experience (of reading through this thread)is going to be detrimental to anyone in the long term.

To put it in simpler words... it's good to get some higher level reading practice.

Also, I will be the first to admit that my spelling is mediocre.

SSS 18734
06-25-2008, 04:28 AM
SubSonicSounds,

I'm shocked whenever I see someone on this site that has even a basic knowledge of the English language. The fact that you can structure sentences is fantastic, and as such, I would assume that you're looking for some knowledgeable people to share your ideas with.

Therefore, I would HIGHLY recommend you visit the forum at www.soundsolutionsaudio.com and post your discussion there.

More often then not, this forum is a complete joke. (Which is why I love it so much) :D

helotaxi
06-25-2008, 06:50 AM
Yep, it really is nice and somewhat shocking to find complete sentences on this forum. SSA has a higher audio IQ on average than this place. The trolls and idiots here chased a lot of the smart guys over there and few of them make very regular appearances here any more, though some of them are, in fact, mods on this forum.

PV Audio
06-25-2008, 11:03 AM
If anything, ask this on diyaudio.com or avsforum.com. Both sites would gladly help you if you conduct yourself in a professional fashion, but be warned, their collective sense of humor is nonexistent.

PV Audio
06-25-2008, 11:05 AM
I write in a highly technical fashion in order to avoid any ambiguity in reader perception of my statements. I think it is approiate for the desired level of technicality in the discourse of this particular thread.

While I do understand that writing may seem shifted towards the advanced end of the spectrum, I certainly do not think that the experience (of reading through this thread)is going to be detrimental to anyone in the long term.

To put it in simpler words... it's good to get some higher level reading practice.

Also, I will be the first to admit that my spelling is mediocre.I don't think you answered, but what do you do for a living/major?

MisterGrubbs
06-25-2008, 11:23 AM
I resent the idea that everyone here is an idiot, although you hit right on the head PV when you said the majority of people here are idiots.

Also, your spelling is fine Subsonic, but do yourself a favor. Read over some of the comments from various posts, look at them, you'll see that in fact most of the people here are just trolls or jackasses, there are still some people who honestly want to learn more about the hobby, but they're getting few and far between these days.

On the other hand, I dont like SSA - too many people there try to act like they know everything in the world. There are more(in general) knowledgeable users there, but a ton of them act too **** cocky all of the time and feel as though you have to be inferior to them.

Cheers for using correct grammar, once again. You, PV, and helo are some of the few around here that do it. Thread back on topic, I wont comment because PV and helo are a bit out of my league in knowledge :-)

PS - I understood what was said in the previous posts. I might not understand some of the theories behind what was stated, but it was more than bearable to read.

PV Audio
06-25-2008, 11:51 AM
I resent the idea that everyone here is an idiot, although you hit right on the head PV when you said the majority of people here are idiots.

Also, your spelling is fine Subsonic, but do yourself a favor. Read over some of the comments from various posts, look at them, you'll see that in fact most of the people here are just trolls or jackasses, there are still some people who honestly want to learn more about the hobby, but they're getting few and far between these days.

On the other hand, I dont like SSA - too many people there try to act like they know everything in the world. There are more(in general) knowledgeable users there, but a ton of them act too **** cocky all of the time and feel as though you have to be inferior to them.

Cheers for using correct grammar, once again. You, PV, and helo are some of the few around here that do it. Thread back on topic, I wont comment because PV and helo are a bit out of my league in knowledge :-)

PS - I understood what was said in the previous posts. I might not understand some of the theories behind what was stated, but it was more than bearable to read.
:laugh: Quite true sir