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Discussion Starter #1
I have a 2007 BMW E90 335xi with the logic 7 sound system. Honestly, the audio is not bad at all. The issue comes up when I raise the volume. The system just doesn't have enough power for me and sounds muffled.

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This is my plan:

1) Purchase wire harness to power MOST converter and allow me to not butcher factory speaker wires.

2) Purchase MOST converter

3) Purchase audison ap-f8-9-bit

3.5) Also purchase a tiny subwoofer amplifier for that 9th channel?

4) Wire it all up, say a prayer to the paypal credit (and stimulus check) gods, and have glorious clear audio.

What I don't understand: How does bmw drive these thirteen speakers with only 9 channels?

I'm still a little confused about how I am going to tune this whole thing.

Maybe I should consider getting a cheaper DSP and not driving some of the rear speakers.

Thoughts?
 

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They are probably running all the tweets and woofers (or mids) in parallel. Hence, the appearance of 4 less speakers at the amp end.
 

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We were fortunate to not have Logic 7 so I won't speak to that.

We replaced the up front drivers (see signature) and ignored the rear drivers.

We have the BMW SOS dash light on but it's pretty easy to ignore that.

If I were to do it again, I'd use the AudioFrog GS8ND2's under the seats.

If I were to do it again, I wouldn't buy an e92. (But that's another story)
 

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I had my E90 with Standard HiFi before I’d started down this journey of SQ and tuning. The tweets are in parallel to the mids on the four corners. I was running a JBL MS-8 on BSW speakers including adding a center to my HiFi package. I left OEM woofers under seats and powered them off the same amp I was using for my 10” JBL sub in a sealed box. I had a JL XD500v2 3 channel handling all the bass. The tuning was handled by the MS-8 autotune. Other than limited volume, I was happy with the setup for a simple OEM upgrade. I still have the BSW speakers if you’re interested in upgrading some of your L7 drivers.
 

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If you’re just doing a front seat tune, I’d say leave out the rear doors all together and let the rear deck run in parallel. Focus on your front stage, which you can using a 10 channel DSP with room for added subwoofer(s) or run an 8 channel with the OEM woofer locations as sub bass and leave out the center. In my 8 channel setup, I was not running active DSP on the front midrange and tweeter.
 

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On the OEM BMW setup; they have the tweeters and the midrange running off the same output channel.
They just put a 'bass blocker' capacitor inline with the tweeter, to cut out the lower frequency.

For your setup, here's what I would recommend:
  • 6 active channels to the front: Tweeters (in the sail panel), Midrange (in the doors), and Midwoofer (under the seats).
    • For this; you will need to run an extra speaker wire from the Audison amp into the front door, to power the midrange.
  • 2 channels to the rear doors (for rear fill).
  • 1 sub output channel from the Audison to a separate subwoofer amplifier.
Forget about the center channel, it's not needed (and just messes-up the front stereo imaging).
Forget about the rear shelf speakers (they completely balls-up the sound stage).

The thing you didn't mention was; what speakers are you planning to use?
If you are intending to add all of this aftermarket equipment, and use the factory OEM speakers; then stop the project now...

The OEM speakers are some of the cheapest garbage you will ever see. You 'might' get away with using the OEM underseat midwoofer... but unlikely.
The rest of the speakers are not suitable for this kind of upgrade. In the end; even if you pray to the PayPal Gods... You won't realize any improvement.
 

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Discussion Starter #7
Thanks for the responses, guys. It is sounding like I am going to have to sacrifice some factory speakers to avoid paying up the @$$ for some crazy sound processing setup. And even if I did, upgrading the speakers should be #1 priority, not the amplifiers.
 

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Discussion Starter #8
We were fortunate to not have Logic 7 so I won't speak to that.

We replaced the up front drivers (see signature) and ignored the rear drivers.

We have the BMW SOS dash light on but it's pretty easy to ignore that.

If I were to do it again, I'd use the AudioFrog GS8ND2's under the seats.

If I were to do it again, I wouldn't buy an e92. (But that's another story)
Can you tell me more about putting the audio frog subs under the seat? Has someone posted a thread on these? This sounds interesting, but those subs look huge!
 

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If you search DIYMA for GS8ND2 you will find some posts.

I bought the xe200's from Musicar NW. They said, at the time, that was the best driver available, that fit.
I also bought the sub box from them. Very nice build quality.
They also said the GB40's were perfect for the front doors. Designed for them, infact.
I had already planned to use the Morel tweeters and sub but the GB40's were a couple months out.
We installed everything but the GB40's and the system sounded OK. But the mid bass was definitely lacking. The Jehnerts really don't do much. Even with 200 watts.
Then the GB40's came in and OH MY, they are fantastic. Made the mid bass and vocals really come alive.

Since then I did the XC90 in all Frogs. And I'm firing two 12's into my underseat area.
I also did my Triumph with Frogs in the doors and Kicker T's under the seats. The Kickers T's need very little room and man, do they rock.

So yes, I'm a big fan of underseat bass. I would verify that the GS8ND2's would fit and then use them for sure. Or see if I could squeeze in some Kicker T's. :p

Side note. You will want to run independent leads for the tweeters into the doors if you want to do the active system properly. Where I compromised was in running the 8's and 12 on the same sub signal from the Pioneer HU. Then separating them at the amps.
 

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We do now have a complete DSP MOST25 1KW amplifier now available. It is a BMW version of our OEM manufactured unit developed for an OEM. It comes in an 8.1.1 (there's an extra preout for adding an additional sub amp) configuration. The unit comes with a 300W RMS sub channel, 2x120w RMS high powered channels and 6x75W RMS. We'll be listing the complete details on the amp in the coming days on our website.

cheers,

mObridge
 

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Discussion Starter #11
In case anyone in the future is reading this and wants to mod their e90 sound system I want to share what I did.

1) Obtained and installed the coveted BMW individual audio amplifier (supposedly 825 watts split into 9 channels vs. the Logic 7 425 watts)
2) Got a set of bavsound front stage speakers, and v2 underseat woofers (8 ohm version because that is what the individual audio requires).

I put everything in. Played some brown noise. Used my cell phone RTA app (probably not accurate at all).

At moderate and high volumes, the sound is definitely better. Not amazing, but definitely better.

Is it worth the ~$1200? HELL NO.

I really love playing bon Iver's latest stuff cranked so loud that it gives me chills.
This system 100% disappoints me in this regard. Sound gets really harsh and generally just sounds more painful than pleasant.

I'm thinking about changing things up to something like this:

1) The mobridge AMP + DSP mentioned in post 10 OR the audison AP F8.9 bit.
2) Audiofrog GB40 + GB10 (passive or active? I really don't want to rewire them to active. Are the crossovers in the kit good enough? They are like $500? WHY ARE THEY SO EXPENSIVE? For that alone I should suck it up and run two sets of wires for 3 way active)
3) Audiofrog GS8ND2 under seat subs

Maybe a fitted stealth subwoofer in the trunk depending on how the GS8ND2s perform.

Anyone want to share their $0.02 on this new approach?

My old car had Hybrid audio tech front stage and acoustic elegance IB subs. I thought I didn't need all that this time, but here I am designing a crazy system again... I loved that setup. Miss it more than the car.
 
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