e39 free-air / infinite baffle vs enclosure box sub setup

[zzvelik]

I've had my e39 for about a year now and am finally ready to upgrade the stereo system. I've perused various e39 threads about installing after-market sub(s) in my e39. I have a pair of Focal 6.5" components for the front and a JL Audio 400/4 to power them (still not sure what to do with the rear speakers). My listening taste is geared towards audiophile recordings of rock and jazz, so that last thing I'm looking to accomplish is the boomy bass of hip hop. I was thinking that guess that one or two 10" subs would more than suit my needs. I searched all over these audio threads and was almost set on going the "free-air" or infinite baffle route via the rear deck (like the M-audio) or behind the rear armrest like this guy:

http://forums.bimmerforums.com/forum...=e39+subwoofer

Yesterday, I went to a pro car audio shop without my car and the manager advised me against the free-air/ib route. He recommended a custom enclosure with one sub instead and suggested that I bring my car to discuss what he could do. According to many posts I've read on the BMW forums, BMW's are very sound proof and I'm not sure how a sub box in the trunk would sound. I'd like to hear from the experts out there on what type of setup would generate a tighter, less boomy bass. TIA

[Benny Z]

do you have folding rear seats? ski pass?

[zzvelik]

No folding seats or ski pass. By the way Benny, I was drooling over those 8" fronts you had shown in your e46! Had I gone that route, no need for subs in my car. ;-)

[Benny Z]

haha - yes, i actually ran subless for a while when i first installed the legatia 8s in the e39.

no folding seats, no ski pass...you are indeed a candidate for an IB setup. you do at least have the folding arm rest in the rear seat, right? w/ a metal plate behind the leather flap blocking off the trunk?

[PScalfano]

IB FTW!

[zzvelik]

Yes, I do have a folding rear armrest in the back. Would a sub behind it be preferable over an M-Audio type setup? I was hoping to maintain the stock look, but I'm planning on keeping the car for a while, so I may opt to cut through that armrest if the end result is worth it. By the way, I've seen some pics of a square sub in that location. I wonder how that sounds compared to a standard round sub. Also, I'd like to hear recommendations on some IB sub types that would go along with a JL Audio 500/1 amp that I'm planning to purchase. Thanks

[Mless5]

I cut an opening where ski pass would be, mounting 15" IB there tomorrow. You don't need to have 15" hole BTW. IB is the best way to go IMO, I am surprised so few people run IB. I tried them all, trust me.

I'd love to shove (2) 15"s IB, but it will be too heavy.

You don't really need all that much power to IB. Much less that you would run in a box situation so you are all set with that 500/1 - they are great amps.

Square has more cone area compared to the same size round, but I've never tried those Kicker squares. In IB the more cone area you have - the better it is, thus my comment of (2) 15"s.

[zzvelik]

Couple of more questions about the setup:

1. I'm close to getting the JL Audio 500/1 amp, but can also get the 250/1 amp for the sub. Would the 500 be too much for my needs (one or two 10s)?

2. I have a JL Cleans Sweep CL441dsp to use for my aux input. Not sure how that's going to work out as far as steering controls and the location of the aux input goes. Anyone have experience with the CS? I had read that it wasn't necessary for the non-dsp system, but due to the aux input and sub controls, I thought it wouldn't hurt to include one in my system.

Thanks

[PScalfano]

1) I use a 250/1 for my (2) 10s. I do not feel the need for more watts, but that's just me.

2) I did not use a cleansweep. The factory signal worked fine straight from the bmw radio.

[zzvelik]

I've seen many here use sound dampening foils and was wondering if you're using Dynamat or know of a good alternative? I read the "Everything about everything..." sticky section 5.10 regarding Dynamat alternatives and ran across these links:

http://www.mcmaster.com/#sound-reducers/=8u0uoz

http://www.mcmelectronics.com/produc...00916-/LS00916

http://www.amazon.com/Sound-Deadenin.../dp/B000M4K14Y

One more question...

If I go ahead with the JL Audio XD400/4 amp for two pairs of speakers and either the 250/1 or 500/1 amp for the subwoofer, would I need to add a capacitor in my setup? TIA

[Mless5]

www.sounddeadenershowdown.com
Noise blocking and killing vibration are 2 different things. Be smart about what and where.

No capacitor needed. Capacitor = marketing BS. I ran 4 amps with no problems. Aim for 500/1. Having more power on tap than you need > not enough power.

[zzvelik]

1) I use a 250/1 for my (2) 10s. I do not feel the need for more watts, but that's just me.

2) I did not use a cleansweep. The factory signal worked fine straight from the bmw radio.

PScalfano,

I wasn't able to see your pics during earlier in the day. What brand of subs are those in the picture and how much of the rear deck did you have to cut? A pic from above would be nice as well. Thanks

Mless5,

I got carried away with google & need more time to read up on noise blocking. Thanks for the heads up on the capacitor.

[bondovw]

If you listen to rock and jazz do not do free air. Do some sort of a box ported threw the ski pass.

[GSA1]

IB (Trunk Baffle) FTW!

I just completed an IB/trunk baffle install through the center of the back seat. Cut out is 6 X 9 and finished with a grill. Sub is facing the trunk. It sounds awesome!!

My goals were: SQ over SPL; a stealthy install; very little trunk space used (15 X 15.5 X 9.5 [WxHxD]); cost effectiveness; and complete seperation of front and rear waves. Mission accomplished!!!

I have pics and am thinking of doing a DIY...It works that well.

Original Front Stage Setup:
- Hybrid Clarus C51, tweets and mids
- Rock Fos 360.2 active processor;
- JL A6450 6 channel.

Just added:
- Alpine Mrd 605 sub amp;
- Infinity Kappa Perfect 12" 4 Ohm DVC.

[Benny Z]

I've seen many here use sound dampening foils and was wondering if you're using Dynamat or know of a good alternative? I read the "Everything about everything..." sticky section 5.10 regarding Dynamat alternatives and ran across these links:

i have used a bunch of products. dynamat xtreme is good, but my current preference is second skin's "damplifier pro". it now comes in flat anodized black and is slightly thicker than dynamat xtreme. same butyl rubber type deadener...very cool stuff in black!

[PScalfano]

zzvelik, here is a link to my build thread. It contains more info+pictures on my sub setup.

http://forums.bimmerforums.com/forum....php?t=1089690

[zzvelik]

PScalfano,

Thanks for the link. That must have taken a while, but I'm sure you're reaping the rewards of all that hard work. I went to a pro audio install place yesterday and saw a subwoofer enclosure being built for an e39 that resembled the one featured on the following link:
http://www.thecarstereoguys.com/page2.html
The installer had years of experience and tried to dissuade me from the Infinite Baffle route even after telling him about the many success stories on this board from e39 enthusiasts. He'd only recommend the IB route only for super space saving installs with a BSW type of sub enclosure around it. Same thing was told to me by two other installers.

I picked up a JL Audio 500/1 (v1) mono amp today and will be using that to power the sub(s). I still have to read more pros/cons on placing the subs under the rear deck Free-air/IB method via the M-Audio cutouts or get a custom-built sub enclosure behind the rear armrest/skip pass location. For the record, my car does not have foldable seats nor a ski pass, thus I'd have to do some cutting to get this to work.

I still need to figure out the following:
1. Number (1/2) and diameter (10"/12") of subs: (Here's a sub review link for future reference: http://www.diymobileaudio.com/forum/...n-hx2-cvr.html )
2. Brand, dual/single voice coil, and subwoofer impedance
3. Keep the existing factory 5.25" rear drivers and tweeters or replace them with a new set of coaxials/components in addition to figuring out if their impedance have to match the 2ohm Focal KR2s in the front.

I appreciate all the help from everyone here.

[rogan]

I would love to try a Fi IB3 sub. Designed for IB only and 30mm of Xmax.

I did a pair of 12" IB in my E39. Highly recommended. If you have no ski pass then don't let them talk you into having a sealed enclosure in the rear; it will be hell muted by the air tightness of the boot. Either way you're going to need to open up an airway between cabin and trunk

[Benny Z]

I would love to try a Fi IB3 sub. Designed for IB only and 30mm of Xmax.

hey! that's what imagonna do!

shhhhhh....

[Benny Z]

Quantity Name Item number Unit price Total price
-------------------------------------------------------------------------
1 IB315 01815 USD 189.00 USD 189.00
Ohm: single 4

-------------------------------------------------------------------------
Amount: USD 189.00
Shipping costs: USD 23.12
Total amount: USD 212.12

[zzvelik]

I would love to try a Fi IB3 sub. Designed for IB only and 30mm of Xmax.

I did a pair of 12" IB in my E39. Highly recommended. If you have no ski pass then don't let them talk you into having a sealed enclosure in the rear; it will be hell muted by the air tightness of the boot. Either way you're going to need to open up an airway between cabin and trunk

Either setup in my case would require some cutting. I was trying to avoid cutting as much as possible to retain the stock look, that's why the M-Audio seemed like the logical choice at first. I could also cut a rectangular section behind the armrest with an enclosure setup. Wish there was a way to audition these setups... too bad I missed Bimmerfest this year!

[PScalfano]

zzvelik, thanks for the nice words. I went with the deck install to use the well-sealed nature of the trunk to my advantage, instead of trying to fight it.

I know many installers try not to use IB. The thing about pro installers is they have to install systems any car that is given to them and achieve good (consistent) results. There are many more install constraints with IB installs that vary from vehicle to vehicle. Some cars are harder to seal than others, and there are variances in the same model of car (E39: skipass, no skipass, m-audio cutouts or not depending on build date). Imagine having to discover these things each time someone brings you an automobile and asks you to install a system in it. These variables make enclosed boxes an easier solution for the vast majority of cars to get consistently good sound. I'm not saying that this approach is bad at all, because I can just imagine all the SUV, truck, hatchback, etc, owners who bring their cars to pro installers where this type of sub setup would not even be considered.

Our cars, especially without fold down seats or a skipass, are definitely an exception to the "use a box" rule of thumb, though. (this is my biased opinion)

[Mless5]

^ absolutely agreed. It is easier for an installer to throw a box in and call it a day. You are after quality sound, not quick and easy installation. IB will sound much better in the end.

[zzvelik]

I'm leaning towards a pair of 10" Infinite Baffles in my e39. Just a few more Q's for those who've installed IB's in their e39's or other BMWs:

1. How much of the rear deck was cut (the 4" cutouts or the entire whole 10")?
2. Did you re-reupholster the top of the rear deck?
3. Most important: What type of Subs did you use?
(Please shed some light on the dual 2ohm/4ohm voice coils as I'm not sure how to optimize it with my amp and 2ohm Focal KR2's in the front).

Below is a list of IB subs I've read about in the forums:

AE
Diamond Audio
DLS: OA10
Element Designs
Fi
Infinity Kappas

Feel free to mention any others that should be added to the list, especially 10" subs that are designed for Sound Quality rather than SPL.

Thanks again,
Z

[Benny Z]

y the rear deck vs a bigger single sub through the ski pass? cutting out the ski pass in these cars is no big deal...easier than the rear deck IMO.