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View Full Version : Clamshell? Bandpass? Wanna do 150 burps.



SeanDub
03-24-2008, 07:04 PM
Alright, well I just got my AudioControl Epic 150 in my dash, and of course, now I want to be louder. My 9515 is at 146 right now off my 2k6d at 0.5 ohm on a 45 hz tone. I want to break 150, and I'm thinking about doing something fun this summer. I don't want to buy a pair of HDC3 15s or another 9515 or anything like that. Also, I want to be able to use my 2k6d because people are bashing them, their resale value has dropped, and I love the little thing.


Therefore, lately, I've been looking for a way to greatly increase my surface area and use a sealed box. I thought about a bunch of 15s, like the MAW 15s from Mach 5, but I don't have the space to put enough back there without my amp burning them up. However, I did find a great deal on some Audiobahn AW1051t subs. Little 10" woofers, handle around 300 rms. My first system was a pair of AW1251t 12s, and they were great back in the day. So I think the 10s will be good for this plan.

So here is my idea:
10 Audiobahn AW1051t 10" Dual 4 ohm subs (all of them will wire to 0.8 ohm)
They will only cost me $345 for all 10, so for $34.50 shipped a piece brand new, I think it's a good deal.


Now on to the box. Quite frankly I don't have enough space to run 10 10s on one surface. But I don't want to put 10 10s back there and just get a bunch of cancellation, so I want to make sure this will work. My initial thought was a sealed clamshell, around 7.5 cubes net, for 0.75 per 10. However, is there any theory behind clamshell boxes? I have found none.

Something like this, but with 10 10s instead of 8 15s:
http://img180.imageshack.us/img180/6238/clam1ot1.jpg (http://imageshack.us)
http://img265.imageshack.us/img265/8824/clam2vh8.jpg (http://imageshack.us)

But that was just my initial thought, would a bandpass be better? I don't know anything about a bandpass, so I thought I would ask.

mjf
03-24-2008, 07:23 PM
their resale value has dropped due to the problems that have arose with them.

http://www.caraudio.com/forum/showthread.php?t=298134&highlight=sundown+test

not exactly a surprise. good luck though.


anyway, a clamshell in a sense acts like a bandpass due to the opening acting like a port. there are ways to calculate it and tune it through that, but i honestly havent been able to figure it out myself.

SeanDub
03-24-2008, 07:27 PM
their resale value has dropped due to the problems that have arose with them.

http://www.caraudio.com/forum/showthread.php?t=298134&highlight=sundown+test

not exactly a surprise. good luck though.


anyway, a clamshell in a sense acts like a bandpass due to the opening acting like a port. there are ways to calculate it and tune it through that, but i honestly havent been able to figure it out myself.

Yes I saw the thread. I clamped mine. It did 2500 rms @ 2.4 ohm on a poor electrical. It's **** good enough for me.

As far as the clamshell information, I understand that. I was wondering if the angles affect the output. Also, does placement on the slanted face affect how the subs load?

SeanDub
03-24-2008, 08:41 PM
Nothing? I'm just looking to see if there is more to clamshell boxes than the slanting and opening. I hope there is.

tooloud4tv
03-24-2008, 08:50 PM
id run 4 18" Mjs if it were me in an clamshell i honestly think it would be louder.

mjf
03-24-2008, 08:56 PM
well you have to think of it in the sense of a port, because thats all it is

with the opening being slanted it will change the port area, in which case needs to be calculated differently.

if i can figure out the exact numbers ill help you out.

SeanDub
03-24-2008, 09:00 PM
id run 4 18" Mjs if it were me in an clamshell i honestly think it would be louder.

I would, but 4 of them total to $464 shipped. I can swing the $345 off my measly tax return from my summer job easily. Sure the 4 18s would be louder, but I dunno if I wanna pony up the cash for something that will only be in there for the summer. I might though.

I still wanna know how to calculate the affect of different slant angles on output and sound.

jdawg
03-24-2008, 09:03 PM
calmshell, just angle it to get the volume you need. The pic you posted is from 97cavy's truck on here. You could ask him. I think he did first in finals? With the huge opening he has it doesnt act like a port really, if you had them closer it could be similar to a bandpass I guess. He did it to get the volume he needed for the 18's

SeanDub
03-24-2008, 09:06 PM
calmshell, just angle it to get the volume you need. The pic you posted is from 97cavy's truck on here. You could ask him. I think he did first in finals?

I know it's 97cavy's pic, I remembered it from his for sale thread and stole it to post here. I messaged him a day ago, but he hasn't been on in 3 days. I'm hoping he gets on sometime soon though so he can get back to me.

And what do you mean just angle it to get the volume you need? Meaning that the angle had little impact on anything other than the volume taken from the box? Does it affect output?

tooloud4tv
03-24-2008, 09:09 PM
personally if ur gonna spend all taht time and money on doing an clamshell id def put some subs that will be worth it not saying those audiobahns are crap either

Skip01
03-24-2008, 09:11 PM
Why u need a clamshell to break a 150?


But i do love the idea....do some obscure subs that no one likes or something and make it silly loud by adding a bunch of them

jdawg
03-24-2008, 09:12 PM
If you get the woofers too close it may have some effect or act like a port, just keep it enough so its like 2 big sealed boxes. In other words dont worry about it.

jdawg
03-24-2008, 09:12 PM
i seen in another thread his puter is broke and his phone isnt working right with his phone

Skip01
03-24-2008, 09:14 PM
From what i read and seen i dont think its as unforgiving as a wrong ported box

It acts like a 4th order and maybe the angle of the ends and opening play with final tuning, but go for it

SeanDub
03-24-2008, 09:47 PM
Why u need a clamshell to break a 150?


But i do love the idea....do some obscure subs that no one likes or something and make it silly loud by adding a bunch of them

Yeah, I just want a ton of cone area off the power I already have, and I want to do something fun and different. That Bahn series ain't bad for what it is (a 300 rms sub for $35 shipped that can take the 300 rms) they just catch a bad rep because, well, they are Bahns. The 4 18" MJs would be awesome, get louder, and probably sound better, but I'm finding it harder to jump off the Bahns when it's 10 10s for under $350 shipped.


From what i read and seen i dont think its as unforgiving as a wrong ported box

It acts like a 4th order and maybe the angle of the ends and opening play with final tuning, but go for it

That's what I want to hear. I have a design for a box - all 10 in 7.29 cubes sealed with using the 7, 24, 25 right triangle for the angles, gives about 16.x degrees. The whole thing would be 20" tall, 40" wide, and 28" deep. ***** though because my MacBook doesn't have a program like Paint.

SeanDub
03-25-2008, 05:57 PM
bump

TC2k15x2
03-25-2008, 06:04 PM
Ur seriously using audiobahns for an install like this...?

Skip01
03-25-2008, 06:11 PM
Ur seriously using audiobahns for an install like this...?

Why not?

It would be a waste to use great speakers in something that doesnt need much to get loud, just more of....and think of the cost issue with using like 10 good subs...be in the thousands whereas this is only a couple hundred bucks

SeanDub
03-25-2008, 06:35 PM
Why not?

It would be a waste to use great speakers in something that doesnt need much to get loud, just more of....and think of the cost issue with using like 10 good subs...be in the thousands whereas this is only a couple hundred bucks

Exactly. Plus, it's not going to be a permanent setup. I can't afford to take up all that space during the school year because I have to transport my stuff and my girlfriend's stuff to and from campus and home over breaks and the rare weekend. She already complains about the space that the 9515 takes up, and that's only around 6 cubes gross.

So I justify using Audiobahns because of the price/surface area ratio, the fact that I had a pair of the 12s before so I know they aren't as terrible as people think, and the idea that 10 10s on 2500+ watts should easily break 150.

15nissen
03-25-2008, 06:45 PM
maybe your box *****? With your clamped power / woofer a 150+ should be a not a huge issue.

SeanDub
03-25-2008, 07:11 PM
maybe your box *****? With your clamped power / woofer a 150+ should be a not a huge issue.

I don't disagree. But I just can't seem to get this Rodeo loud. I currently have it in 4.25 cubes tuned to 39 hz with around 100 sq in of port. Sub facing rear, port facing rear. I plan to keep this set up for the regular year.

However, I also contemplated a different box. 3.75 cubes net tuned to 38 hertz with 64 sq in of port, sub up, port back. But I don't know if it would any louder.

15nissen
03-25-2008, 08:17 PM
I don't disagree. But I just can't seem to get this Rodeo loud. I currently have it in 4.25 cubes tuned to 39 hz with around 100 sq in of port. Sub facing rear, port facing rear. I plan to keep this set up for the regular year.

However, I also contemplated a different box. 3.75 cubes net tuned to 38 hertz with 64 sq in of port, sub up, port back. But I don't know if it would any louder.

i have never played with a rodeo, but i am a huge fan of aero ports. Maybe something like sub up, port back. Its ALOT easier to tune and try new things when you have aeroports. Its a much cheaper option, and with a loud box, is very possible.:)

BrianChia
03-25-2008, 10:46 PM
What frequency range are you planning on hitting 150 with?

SeanDub
03-26-2008, 03:27 AM
What frequency range are you planning on hitting 150 with?

I had not considered a frequency range. However, I do plan to use the setup for daily listening as well. Therefore, I'm not looking for anything tuned to 60 hz or anything.

But now that I think about it, I would like to break 150 in the 40 - 50 hz frequency range, preferably as close to 40 as possible just out of personal preference.

BrianChia
03-26-2008, 05:51 AM
How much space are we looking at here?

SeanDub
03-26-2008, 08:18 AM
Max gross cubic feet is around 16 cubic feet

SeanDub
03-26-2008, 06:26 PM
bump

SeanDub
03-26-2008, 10:56 PM
So is there no clamshell theory?

DBDRAGGUY
03-26-2008, 11:09 PM
I have done 2 similiar setups 1 with 6 Kicker comp 15's into the cab of a Ranger, and another with 8 12" DEI studios. 15's were in a V into the cab was built into a truck cap. And the 12's were in dual diamond 1 behind each headrest. The 15's moved the most air and would do consistent 155's on the Audiocontrol. The 12's would touch 150's but I believe their was some cancellation issues. Both setups were powered off the same 1200 watt Mmats amp. It is a good bang for the buck setup. I would suggest using woofers that require small sealed enclosures to help with cone control.

SeanDub
03-27-2008, 08:38 PM
Meh, how's this look?

http://img186.imageshack.us/img186/422/1010clamshell1zh6.png (http://imageshack.us)

http://img186.imageshack.us/img186/7012/1010clamshell2hz7.png (http://imageshack.us)

It's around 7.5 net, but a little bit less. I think it looks good and will work nice, if I end up doing this.

BrianChia
03-27-2008, 10:12 PM
Just put it in a big ported box. It should get louder than that sealed clamshell design.

SeanDub
03-27-2008, 11:28 PM
Just put it in a big ported box. It should get louder than that sealed clamshell design.

The 10 10s? Or the 9515?

If you meant the 10s, I don't have room for 10 10s ported.
If you meant the 9515, everyone else says put it in a smaller box with aero ports. But the aeros are too long to get a decent tuning frequency and fit in my car.

Also, why wouldn't that sealed clamshell get loud?

SeanDub
03-28-2008, 11:08 AM
Well then what about this?

9.55 cubes net. Subs up, port back.
4 6" Aero Ports, tuned to 38 hz.

http://img247.imageshack.us/img247/3712/612sportedxm2.jpg (http://imageshack.us)

6 12" Audiobahn AW1251t subs, total cost - $216.82 shipped ($36.14 per woofer)
Wires to 1.335 nominal, should rise to around 3, which would be around 2kw from my Stetsom.
That means they would each see around 333 rms, and their rated rms is 400.

These have the same cone area as around 8.5 10s, and each woofer will see more power.
So it should be of comparable loudness to the 10 10" clamshell design.


But it should definitely be louder than my 9515.

PSturmer
03-28-2008, 01:24 PM
^^^^ a design like that will get decently loud.

SeanDub
03-28-2008, 11:17 PM
So this is all the input I can get out of "the internet's leading car audio resource?"
:rolleyes:

PSturmer
03-28-2008, 11:53 PM
the best resource is simply trying new things out yourself. to start, a wall is not needed to do 150. 2 12's and will can fairly easily do 150 on a burp

SeanDub
03-29-2008, 12:29 AM
the best resource is simply trying new things out yourself. to start, a wall is not needed to do 150. 2 12's and will can fairly easily do 150 on a burp

I don't want to do a wall. Also, I know 2 12s can do 150 burps easily. But I want to keep the amp I have. I clamped my Stetsom at 2500 rms at 2.4 ohm. So I have a good bit of power, but that 2.4 is risen up from 0.5 nominal. Therefore, when I start dividing up the power between woofers, it gets less and less. There aren't too many pairs of 12" subs that can get up into the 150s with 1200 - 1500 rms a piece in an SUV. But they are available. However, they are not cheap. The best option would be the HDC3, but even they are over $400 shipped, and I don't think there are any more in stock.

Therefore, my idea here is to just get louder by adding cone area. And I'm also well aware that the best resource is to simply try new things. However, new things cost money. That's why I'd like to get this right on this try.

I like the idea of the 6 12s ported better than the 10 10s in a clamshell. But I don't know how it will actually work out, so I'm just asking for input.


And I do appreciate your input.

jeremiah
03-29-2008, 02:19 PM
dud 4 mj's in a bandpass would do a 150 and sound good doing it to

SeanDub
03-29-2008, 04:49 PM
dud 4 mj's in a bandpass would do a 150 and sound good doing it to

Dud, 4 MJs in a bandpass would take more space and money than I want to give up on this project.

hunterw
03-29-2008, 05:53 PM
I think if you don't wall a clamshell or a big box you will have a ton of cancellation problems right there. =(. also how much time and money do byou plan on spending on the box. you gain 1-2 dbs by making your box stiffer and smoother. (resin,wax,threaded rod) which adds up. though its not needed to do 150s it helps lol. I think the 6 12s idea seemed good. (i don't know anything about sealed clamshells) also lots of internal angles help a lot as well, rounding corners, and also internal pieces about 8in deep to split the subs up to help with cancellation.most of the time suvs like subs up and ports back. subs and ports back work well as well, but I don't thi.k that will work in your plans. putting the subs as close to the side the port is on helps a little bit as well. though im not 100% surr how much lol.do you kno the res. freq of your rodeo?

Chevyaudio
03-29-2008, 06:00 PM
Keep what you have and make it louder...those woofers are worthless. Installed MANY of them in various cars at the shop I used to work at. With what you have you should be able to accomplish that goal...and only spend 20 bucks on a sheet of MDF.

SeanDub
03-29-2008, 06:15 PM
Keep what you have and make it louder...those woofers are worthless. Installed MANY of them in various cars at the shop I used to work at. With what you have you should be able to accomplish that goal...and only spend 20 bucks on a sheet of MDF.

That was the original plan before this idea. However, it is proving more difficult than I thought it would be. To get louder, I figured I would use external aero ports and a smaller box. However, I don't just want a fart box, I want something that will play music for daily driving as well. So I decided to go with around 3.75 cubes net, and use a pair of 6" aero ports. But in order to tune to 38 hz, each port has to be 24" long! My longest max dimension in the back of the Rodeo is 40 inches. 40" - 24" = 16". On top of that, the port opening is supposed to be approximately as far away from a surface as it is wide. 16 - 6 = not enough surface area left for me to mount a 15" sub. :crap:

So I'm still playing around with more volume and higher tuning, because that would allow me to fit everything back there. However, the people who have used these 9515s say that an SPL box is around 3.5 net. So it just doesn't seem like it's going to work out.

Brassler07
03-31-2008, 12:19 AM
I don't disagree. But I just can't seem to get this Rodeo loud. I currently have it in 4.25 cubes tuned to 39 hz with around 100 sq in of port. Sub facing rear, port facing rear. I plan to keep this set up for the regular year.

However, I also contemplated a different box. 3.75 cubes net tuned to 38 hertz with 64 sq in of port, sub up, port back. But I don't know if it would any louder.

You should do a box with interchangeable ports one tuned high to the frequency of you cabin for SPL and one for daily.

iamamp3pimp
03-31-2008, 08:38 AM
You should do a box with interchangeable ports one tuned high to the frequency of you cabin for SPL and one for daily.

those ****.

imo

MikeyB
03-31-2008, 08:50 AM
Dont use the audioblings. Make a wall with like 15-20 Roadmaster 8's.

1LOWCHIEF
04-01-2008, 12:38 AM
Was that done using Sketchup? Either way, looks good.

Also, being a relative NOOBcomer coming back into car audio, would you want to wire something like that out of phase, as from the top box to the bottom box or would the subs firing together into each other create more air pressure out of the wedge as opposed to canceling each other out?

ha... oops, posted without looking at what page I was on.

The out of phase question is regarding the clamshell box, and the box plans posted in this thread look like they were done in Sketchup.... just looking for verification.