New underseat sub option?

[TaylorFade]

Hello, all! Brand new to the BMW world and glad to be here. Coming from an STi but I am loving my 135!

Anyway... I'm a car audio nut. I compete in SPL and SQ on a world finals caliber level (world champ and world record in SPL) and the first thing I wanted to do was upgrade my sound. So I've been doing a ton of searching and reading on options.

I really wanted to avoid adding a trunk sub so I've been looking for the best option for an actual underseat sub; not a midbass trying to play sub bass. I looked at all of the usual suspects and then started hitting up the brands I'm most familiar with for options.

Not sure if you guys are familiar with Stereo Integrity, but he (Nick) makes the best shallow sub on the planet- the SI BM. I emailed him half jokingly to make me one in an 8" flavor. He was very quick to respond and to tell me that he actually had one in the works. Sweet.

This may not be a drop-in, but it sure looks promising as an actual subwoofer that may go in our cars. He was kind enough to share some renderings with me so I'll share them here for anyone looking.

This is the Stereo Integrity TM9. It's a bit deep for us (I think) at 2.25". Will that work? It also utilizes XBL^2 motor topology. Which is a patented technology that has a very falt BL curve and amazing linearity. It will have 11mm of xmax. Wow. And uses an arachnid suspension. Grills may not be an option with that depth and throw. Geez.

Anyway... tl;dr. On to the renderings. ETA according to Nick will be around December.





Arg! What to run until December!?

[AKopp]

You can replace the speakers until you're blue in the face and I don't think you'll get the results you want. Consider replacing the amp as well. Talk to Ken at MusicarNW. My setup is arriving this week and he really knows his stuff. I'm doing a Level 2 setup with a 10 in the trunk. Replacing the front door mids and tweets and replacing the under seats with 8" midbass. One amp for the sub, one for the mid ranges. The sky is the limit with these guys. And everything is plug and play made from them. There are a few guys that have extensive work done with the guys. Take a look around at http://www.musicarnw.com/

[kaigoss69]

Wow nice! I think it'll probably fit, but you may need to make some mods to the enclosures. There are a couple of obstacles though to being able to get good bass output from the OEM enclosures. There is a "port" that connects the enclosures to the side sill cavities, and per one of the designers of the "BMW central bass system", this port is a bit restrictive to proper air flow so it acts as a Helmholz Resonator (bass trap). The other issue is the total volume of the enclosure, and the type of the enclosure. The side sills are somewhat open to the outside due the presence of plastic drain plus in the bottom. So it is not sealed, it is not IB, and it is definitely not ported. If I had to take a guess, I'd say it acts like a leaky sealed enclosure.

[Adam135]

Earthquake SWS-8s with speaker spacers powered by a JL XD700/5. Really happy with it.

300 Max
2 1/8" mounting depth
Over 1.5" long throw excursion
1.5" aluminum VC (4-ohm)

[AKopp]

I have the Jehnert 8" woofers coming for my set up. I don't know if any are direct fits. I believe they need spacers or a bit of modification, but I may be wrong.

[TaylorFade]

Thanks for the replies, guys. Yeah... I will probably run the Earthquakes until these come available. Where so I get those spacers?

I did actually speak with Ken at MusicarNW. He was extremely generous with his time and advice. Very impressed with his knowledge and expertise. I am considering the Gladen One 200 BMW set from him also.

The amp will be the first thing I do. I have a Zed Leviathan or a Mosconi 120.4dsp waiting in the wings, but I have yet to be able to get in touch with Technics? for a harness. I assume he's a very busy man, but that's all I'm waiting on for the amp install. Although, I am loving how the JL XD 6 channel is fitting in the stock location so that might be an option if the Mosconi doesn't go there.

[TaylorFade]

Originally Posted by kaigoss69

Wow nice! I think it'll probably fit, but you may need to make some mods to the enclosures. There are a couple of obstacles though to being able to get good bass output from the OEM enclosures. There is a "port" that connects the enclosures to the side sill cavities, and per one of the designers of the "BMW central bass system", this port is a bit restrictive to proper air flow so it acts as a Helmholz Resonator (bass trap). The other issue is the total volume of the enclosure, and the type of the enclosure. The side sills are somewhat open to the outside due the presence of plastic drain plus in the bottom. So it is not sealed, it is not IB, and it is definitely not ported. If I had to take a guess, I'd say it acts like a leaky sealed enclosure.

That's... disheartening. All this time I assumed they were effectively IB.

Has anyone tried to "tune" them? a' la aperiodic membrane?

[kaigoss69]

Originally Posted by TaylorFade

That's... disheartening. All this time I assumed they were effectively IB.

Has anyone tried to "tune" them? a' la aperiodic membrane?

I thought about it once, but honestly it sounded like too much trouble. Much easier IMO to use the underseats as true midbass, and put in a trunk sub.

[TaylorFade]

Originally Posted by kaigoss69

I thought about it once, but honestly it sounded like too much trouble. Much easier IMO to use the underseats as true midbass, and put in a trunk sub.

If I go with a trunk sub, I am probably going to get the JL HD 900/5. Where do you have yours? Do you have a corner trunk box? Or just a link to your build?

Thanks.

[1&done]

Originally Posted by kaigoss69

I thought about it once, but honestly it sounded like too much trouble. Much easier IMO to use the underseats as true midbass, and put in a trunk sub.

Yup. Look at the level 3 sub pkg from Ken at Musicar. I'm running it now, the Morel 10" is super clean and the enclosure looks OEM. I have the 6ch amp under the sub and the sub amp next to the battery. It's all stealth

[tjswarbrick]

Ancient Thread Resurrection!

Taylor - do you still have your 1er, and did you get the Earthquake sub?
Have you replaced it with anything else?

I picked up a pair of SI TM65's, and two really good installers very familiar with BMW have told me not to try to put 'em underseat - just go with existing slim 8's.
I also have a pair of BM MKiV's for the trunk, if needed, so I'm just looking for midbass underseat.
The TM9's seem to be vaporware.

[dubluv17]

If you want true sub presence, I just don't see it happening with two shallow 8" drivers. And if it can happen, what about mid range frequencies? They won't be as tight and responsive. I can see 8" drivers capable of reproducing sub frequencies, but I don't see them reproducing them at a sufficient level. I probably have the cheapest 8" underseat option available, the Kicker SSMB8's, with a 10" sub in the trunk and I LOVE the setup. I low pass the sub at ~75hz and bandpass the 8's from 75hz to 200hz. Granted, I haven't heard any other setups in a 135i, but it's really nice having that midrange presence (I also came from a subaru with 6.5" components in crappy doors and didn't have much midrange). If money wasn't an option, I'd probably go with the Morel ADMW 9s and a solid 10" or 12" in the trunk. Get the tuning right and you have drivers that are only working where they are comfortable working. My two cents, but I'm nowhere near an expert.

[tjswarbrick]

If that was directed to me - thank you.
Glad you like the Kickers!
BM MKiV's noted above are shallow (3" deep) sound-quality focused 12's with more than reasonable output. So I'm pretty well covered there. And midrange frequencies will be taken care of by 4 inchers in the factory upper-door locations. Along with replacement tweeters in the sail panels, external amps, and DSP.

As noted above, I'm just looking for quality midbass drivers that'll fit the factory underseat locations. My installer doesn't think my slim 6.5's will be very easy to squeeze in there. He did mount ADMW9's in a BMW once - they didn't really "fit" and he's not going to do it again. I'll probably go with Jehnert or Gladen, but am always interested in additional opinions.

[tracer bullet]

I was impressed with the HK underseat speakers after I amplified them. They were decent before, but really got strong w/ some extra power.

Sub in the trunk (low passed of course, and the underseat mids subsequently high passed) really completed things. It won't win an SQ or an SPL competition, but it sounds darn good.

If you're going the sub route you might be happy with some stock HK speakers there. They'll drop right in and if you can find a set that's been taken care of they'll likely have some good life left in them and be cheap both.

[dubluv17]

Originally Posted by tjswarbrick

If that was directed to me - thank you.
And midrange frequencies will be taken care of by 4 inchers in the factory upper-door locations.

Kinda asking a lot to have 4" drivers playing down to ~150 hz with reasonable output. Going to be running Morels?

[tjswarbrick]

Mids are old - school 4" mids from a/d/s 344is component set. Supposed to be good to below 150Hz. But that's just a starting point for the DSP tune. Morel or HAT Carbon do well down there, too. But then you're looking at the big bucks.

[dubluv17]

Originally Posted by tjswarbrick

Mids are old - school 4" mids from a/d/s 344is component set. Supposed to be good to below 150Hz. But that's just a starting point for the DSP tune. Morel or HAT Carbon do well down there, too. But then you're looking at the big bucks.

I've always heard old a/d/s stuff was awesome, but could never find any to try out. :-(

[tjswarbrick]

I had a set (but not this one) in my Jetta in the '90's. They were fantastic. Sadly, I was stupid and left 'em in there when I traded it in. Got these mids from a guy upgrading from his E90 M3. Can't wait to hear 'em in-car.

[tjswarbrick]

Quick update if anyone was following this.
My installer put some Gladen HG 201 8" underseat midbasses under the seats. In his experience they are not a good "subwoofer" in this car, but are a great midbass.
Underseat in my convertible, almost regardless of crossover tuning, they go solid down to about 50Hz then drop off rather sharply.

I've haven't listened to them myself, but have it on good authority that the Jehnert XE200 is a nice underseat option if you want low bass but refuse to add a real subwoofer.

The BM MkIV's I bought wouldn't fit stealthily, pretty much anywhere in the car. So I sold 'em. There are a couple less expensive options which may work, but I now have an Illusion C10 sitting up front for true low bass. Only took about 2" away from passenger leg room, and causes no rattles.
And it is awesome!


I'm still working on fine-tuning the EQ and DSP, but bass is taut, powerful, articulate, and impactful with absolutely no boom or resonance.

I also learned that Stereo Integrity is finding it necessary to close its doors. Nick is going to try to stay in the loudspeaker business, but not produce or sell direct. So those TM9's will be very unlikely to ever see the light of day.

[PhillyfaanM3]

I replaced the underseat subs with the Focal 8" Integration series subs. So far really like the way everything sounds. Would highly recommend.

http://www.1addicts.com/forums/showthread.php?t=1067408