E90Post
 


Extreme Power House
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > AUDIO/VIDEO + BLUETOOTH + Electronics/Alarm/Software > Simple Infinite Baffle Sub Install Idea



Reply
 
Thread Tools Search this Thread
      09-03-2012, 04:57 PM   #1
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Simple Infinite Baffle Sub Install Idea

So I'm no expert when it comes to IB / free-air installs, I just know that they have the potential to sound fantastic. The concept is pretty simple: Use the trunk volume as the enclosure, and install the sub(s) in a baffle between the cabin and the trunk. The main advantages of IB are a) very linear frequency response, and b) efficiency.

The few BMW installs I have seen by members SCtud, mathematics and TMR all involved the installation of a separate baffle behind the back seat, with some degree of air space between the two. All of them had ski-passes. My idea is a bit simpler, and I was wondering if anyone with experience would care to comment on the concept.

Basically, I want to bypass having to install a separate baffle, and use the back seat as the main baffle. I would just have a mounting baffle, large enough to mount the sub to and to cover the ski-pass hole, and it would be screwed directly to the back of the seat. The waves from the front of the woofer would all be forced through the ski-pass hole, while the back waves would stay in the trunk. Now I know that the back seat and rear decks do not seal completely to the cabin, but I would think that it would be enough for this concept to work. So, before I go crazy building stuff, anyone with experience care to comment? Am I crazy or could this actually work?
Attached Images
 
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      09-03-2012, 05:42 PM   #2
artiforgs
New Member
0
Rep
11
Posts

 
Drives: 2009 320d
Join Date: Jun 2012
Location: Norway

iTrader: (0)

Could work, but if you take an example of a random woofer..
Lets take the JL 12W7, witch is a BIG woofer. With a lot of air movement.

I may be wrong, but I remember it to require aprox. 60L of ported enclosure. (per element)

And if your trunk is aprox. 400L ? I think it will be too big space, using the trunk as the enclosure..Dont think you will get any air pressure, or SPL if you want..
Appreciate 0
      09-03-2012, 07:41 PM   #3
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

A lot of the subwoofers out there can actually work well in such an environment, including the W7. In my case, I would use a woofer that I know works well, specifically the Infinity Perfect 12 VQ.
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      09-04-2012, 08:50 AM   #4
Mr Singh
Banned
United Kingdom
17
Rep
773
Posts

 
Drives: E91 330D M Sport Auto
Join Date: Oct 2011
Location: Milton Keynes

iTrader: (3)

Rule of thumb is 10x the VAS of the speaker. Check out the IB3 series drivers from Fi Car Audio.
Appreciate 0
      09-04-2012, 09:01 AM   #5
Slow_335i
Daily Driven!
Slow_335i's Avatar
United_States
52
Rep
2,495
Posts

 
Drives: BMW 335i
Join Date: Jun 2011
Location: Peoria IL

iTrader: (11)

Garage List
2008 BMW 335I  [3.32]
My brother had a very similar setup in his Lexus is300. Worked great and looked awesome!

__________________
Appreciate 0
      09-04-2012, 09:32 AM   #6
Mr Singh
Banned
United Kingdom
17
Rep
773
Posts

 
Drives: E91 330D M Sport Auto
Join Date: Oct 2011
Location: Milton Keynes

iTrader: (3)

Quote:
Originally Posted by Slow_335i View Post
My brother had a very similar setup in his Lexus is300. Worked great and looked awesome!

Looks like an Arsenal or Chaos 12
Appreciate 0
      09-04-2012, 10:36 AM   #7
Slow_335i
Daily Driven!
Slow_335i's Avatar
United_States
52
Rep
2,495
Posts

 
Drives: BMW 335i
Join Date: Jun 2011
Location: Peoria IL

iTrader: (11)

Garage List
2008 BMW 335I  [3.32]
Quote:
Originally Posted by Mr Singh View Post
Looks like an Arsenal or Chaos 12
Na it's a FI sub, not sure on the model.
__________________
Appreciate 0
      09-04-2012, 11:01 AM   #8
Mr Singh
Banned
United Kingdom
17
Rep
773
Posts

 
Drives: E91 330D M Sport Auto
Join Date: Oct 2011
Location: Milton Keynes

iTrader: (3)

Quote:
Originally Posted by Slow_335i View Post
Na it's a FI sub, not sure on the model.
Its an early IB3. I'm the EU Distributor for Fi Car Audio
Appreciate 0
      09-04-2012, 11:28 AM   #9
Slow_335i
Daily Driven!
Slow_335i's Avatar
United_States
52
Rep
2,495
Posts

 
Drives: BMW 335i
Join Date: Jun 2011
Location: Peoria IL

iTrader: (11)

Garage List
2008 BMW 335I  [3.32]
Quote:
Originally Posted by Mr Singh View Post
Its an early IB3. I'm the EU Distributor for Fi Car Audio
Sorry I googled what you said earlier and a JVC sub and a BOSS sub popped up. lol
__________________
Appreciate 0
      12-04-2012, 05:16 PM   #10
makkan00
Major General
makkan00's Avatar
United Kingdom
127
Rep
7,600
Posts

 
Drives: F10
Join Date: Dec 2011
Location: Essex

iTrader: (48)

Kaigoss this thread may give you some idea.
Not difficult and a lot easier than fitting a sub in rear deck IMO.
Plus you have skyhole (if I am not wrong).
__________________
Appreciate 0
      12-04-2012, 06:09 PM   #11
808MGuy
Colonel
808MGuy's Avatar
49
Rep
2,287
Posts

 
Drives: 2009 E90 M3
Join Date: Jun 2008
Location: Oahu, Hawaii

iTrader: (3)

If not completely sealed off you could get some cancellation. That's the reason most IB setups include a separate baffle behind the back seat. I assume since your thinking about mounting to the back of the seat that you don't have fold down rear seats. If that's the case, you could probably seal up the area that leak pretty easy. A simple smoke test to see where smoke leaks into the cabin would identify that.
__________________
09 E90 M3 - Interlagos Blue / Black Novillo / Sycamore Anthracite / Eibach / HRE

Appreciate 0
      12-04-2012, 07:41 PM   #12
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Quote:
Originally Posted by 808MGuy View Post
If not completely sealed off you could get some cancellation. That's the reason most IB setups include a separate baffle behind the back seat. I assume since your thinking about mounting to the back of the seat that you don't have fold down rear seats. If that's the case, you could probably seal up the area that leak pretty easy. A simple smoke test to see where smoke leaks into the cabin would identify that.
I don't smoke!

I think the back seat is sealed fairly well, but not sure about the rear deck. We'll see, cut the ski-hole today and mad the adapter and mounting plates. Installing tomorrow, using single 12" Infinity Perfect VQ woofer.
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      12-05-2012, 07:41 AM   #13
makkan00
Major General
makkan00's Avatar
United Kingdom
127
Rep
7,600
Posts

 
Drives: F10
Join Date: Dec 2011
Location: Essex

iTrader: (48)

Smashing.
Looked at specs of that sub and it looks promising.
Looking forward to see photos.
__________________
Appreciate 0
      12-05-2012, 08:28 AM   #14
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Well I've had two of them sitting in my attic collecting dust. Figured I'd just throw it in and see what happens. Not expecting it to get too loud, but Andy Wehmeyer said it's a great sub for IB. Next step will be the addition the second one. I'll build a 90 degree wedge to mount them. This will be too obtrusive on my trunk space though I think so it's just an experiment at this point. Still planning on getting a single 15.
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      12-05-2012, 12:15 PM   #15
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Ok so I got my "experimental" set-up completed. I set the Infinity sub to "high Q" with a Qts of just over 0.7. Put in some hip-hop to see what she can do. All I can say right now - with limited listening - is that it gets crazy loud, and the bass is much cleaner with much improved volume and definition in the sub-bass range.

I do have more rattles now inside the cabin (from the increased SPL) so I will have to chase those down, and I will have to get the sub better integrated with the midbass, but that should not be too difficult to accomplish.

A big so far, and I can say that my plans for installing the other 12" have been cancelled!




Uploaded with ImageShack.us
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      12-05-2012, 12:58 PM   #16
e90TiAg335i
Captain
e90TiAg335i's Avatar
United_States
12
Rep
985
Posts

 
Drives: 10 e90 335i
Join Date: Mar 2010
Location: jacksonville, FL

iTrader: (6)

Garage List
2010 e90 335i  [0.00]
Awsome work so far kaigoss. What do you think of it compared to my setup? Is it more linear and/or louder?
__________________

JB4, DP, VMR V710, Sonic Tuning S1 coilovers, Hybrid Ovations, Soundsplinter 10" and Zapco DC Ref amps
Appreciate 0
      12-05-2012, 01:21 PM   #17
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Quote:
Originally Posted by e90TiAg335i View Post
Awsome work so far kaigoss. What do you think of it compared to my setup? Is it more linear and/or louder?
Hey man, thanks for the props. It's too early to tell. I think we may have to settle this in person!
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      12-05-2012, 01:31 PM   #18
e90TiAg335i
Captain
e90TiAg335i's Avatar
United_States
12
Rep
985
Posts

 
Drives: 10 e90 335i
Join Date: Mar 2010
Location: jacksonville, FL

iTrader: (6)

Garage List
2010 e90 335i  [0.00]
Haha, sounds good. I've done a little more work with the alignment on the front soundstage. Last weekend I ran into a new 335 owner and his dad at the dealership. Needless to say, they both wanted to know what they need to make theirs sound like mine!
__________________

JB4, DP, VMR V710, Sonic Tuning S1 coilovers, Hybrid Ovations, Soundsplinter 10" and Zapco DC Ref amps
Appreciate 0
      12-05-2012, 01:58 PM   #19
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Quote:
Originally Posted by e90TiAg335i View Post
Haha, sounds good. I've done a little more work with the alignment on the front soundstage. Last weekend I ran into a new 335 owner and his dad at the dealership. Needless to say, they both wanted to know what they need to make theirs sound like mine!
Yep, you may have to patent "stereo corner-loading".

I still think one can come close to that type of output with the right 12 in a single corner enclosure. I had modeled your two Soundsplinters against a single Ascendant Audio Havoc 12, and the theoretical output was very similar, with 1000W input, vs. your 500W.

If my budget allows, I may still try that in the future, just because I'm curious!

Have you built any more fiberglass corner enclosures, with what equipment, and how did they sound???
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      12-05-2012, 06:14 PM   #20
mob17
Brigadier General
mob17's Avatar
United Kingdom
79
Rep
3,811
Posts

 
Drives: E92 335D
Join Date: Mar 2012
Location: East Midlands, UK

iTrader: (4)

Nice work Kaigoss! Glad to know you're satisfied.

I was also considering one 15" or 2 12" in a 90 degree triangular mount. But i think one 12 should be enough.
__________________
2008 E92 335D SE - Ohlins
2010 E90 320D SE
1994 E36 318I SE
1996 E36 316I SE
Appreciate 0
      12-05-2012, 06:24 PM   #21
kaigoss69
Brigadier General
kaigoss69's Avatar
United_States
63
Rep
3,079
Posts

 
Drives: '08 335i
Join Date: Jul 2008
Location: JAX

iTrader: (5)

Quote:
Originally Posted by mob17
Nice work Kaigoss! Glad to know you're satisfied.

I was also considering one 15" or 2 12" in a 90 degree triangular mount. But i think one 12 should be enough.
Mo, don't hesitate to get the 15 vs a 12! It is always better to have the surface area, since the larger sub will have to move less to make the same output. Less excursion means more defined, cleaner bass with less distortion.
__________________
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa XT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
Appreciate 0
      12-05-2012, 06:46 PM   #22
mob17
Brigadier General
mob17's Avatar
United Kingdom
79
Rep
3,811
Posts

 
Drives: E92 335D
Join Date: Mar 2012
Location: East Midlands, UK

iTrader: (4)

Quote:
Originally Posted by kaigoss69 View Post
Mo, don't hesitate to get the 15 vs a 12! It is always better to have the surface area, since the larger sub will have to move less to make the same output. Less excursion means more defined, cleaner bass with less distortion.
Hmmm that does sound better. The thing is for my particular choice of sub, the IB3 15 is nearly double the size and one of the requirements for me would be to be able to quickly release the sub when in need of boot space. The 15 wouldn't make that impossible, just a bit more of a headache! Also the VAS is 183L, compared to 83L for the 12. I think Mr Singh says normally 10 x the VAS is what you are looking for in terms of boot space so the 12 is already a bit high. However the qts is nearer to 0.7, which is what you or Makkan were saying works better.

If the VAS was lower I would probably get the 15 and deal with the headache of removing it when required.
__________________
2008 E92 335D SE - Ohlins
2010 E90 320D SE
1994 E36 318I SE
1996 E36 316I SE
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:16 PM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST