[taibanl]

Dude, your PMs are off so here is my response:

Originally Posted by kvizzle67

Hey hows it going I just joined this forum looking for advice on my vehicle sound system. Recently just purchased a 08 bmw 335i it does have the top hifi logic 7 system. I am putting a pioneer double din in the vehicle and was going to bypass the factory amp as I was told that is the only way of doing so. I purchased a kicker kx400.4 amp to drive the factory speakers. I'm really not worried about hooking the factory underseat subwoofers as I am adding a separate subwoofer/amp. I was just wondering if you have any advice you can give since I am new to the logic 7 system.

I recommend for you to 1) read the sticky, then 2) post a thread.

Some quick nuggets:
1) you do not need to replace the HU to replace the L7 amp...this is in the sticky
2) you want to replace a 7 channel amp witha 4 channel? not wise.
3) The underseat WOOFERS are just that....not SUBwoofers. Depending on factory or aftermarket they will handle your midbass between a sub ~80hz and your 4" door speakers. You cannot delete that or you will either have a huge frequency reponse gap, horrible imaging, or both.

Thanks for asking for inputs. Better to learn early.

[bmw325i]

Unless you don't mind lower sound quality get a JBL MS8 and a JL Audio XD 600/6. That would actually be an improvement rather than a downgrade. You still want the underseat woofers connected, even if you are adding a sub. You want to use your underseat woofers as midbass drivers. They would play around 60hz-200hz. Your sub can't play that high and your 4 inch door speakers cant play that low.

You can simply use a 4 channel amp and power your door speakers and call it good, but I think the stock logic 7 system would probably sound better than that.

[kvizzle67]

I like the way the logic 7 system sounds however I want to put a pioneer double din into the vehicle. I was doing some reading on the forum and I went ahead and ordered the 2 fiber optic cables to run from the headunit to the trunk and the reverse harness to relocate the factory radio in the trunk. I was going to put a crossover inline between the tweeters and the new headunit and run the tweeters off the pioneer unit and then run the 4" speakers and woofers off the 4-channel or I might just get a 2nd 4-channel so I can set my crossovers properly.

[bmw325i]

There is already a passive crossover between the mids and tweets. If I were you I would get a 6 channel amp. You can have the front speakers on two channels, the underseat subs on two channels, and the center on the 5th channel. If you wanted to you can connect the rear door speakers to the 6th channel in series. You can set the LPF on the underseats to around 200hz and the HPF on the rest to around 200hz, you can do this on the amp.

It would be unprocessed so it may not sound as good to you, it may even sound better to you, it depends. Also be careful with the gain. You can always add a sound processor such as the MS8 later if you decide it doesn't sound good enough.

[kvizzle67]

I wasn't aware there was a crossover between the tweeters and the 4" door speakers, looks like I will be getting the jl xd600/6 amp. Do the rear door speakers have tweeters or is it just a 4 inch speaker and also are there any speakers in the rear deck?

[ctuna]

Depends on the year and stereo system FYI

Read these

BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/showthread.php?t=343673
http://www.e90post.com/forums/showthread.php?t=138949
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/attach...1&d=1209780865
http://www.bawarec.ru/manuals/3er/e9...3er-e90-12.pdf
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...4&d=1278871872

[kvizzle67]

thanks for the articles guys i ordered the jl 600/6 today so I should recieve it this week as well as the other fiber optic cables.

[bmw325i]

Originally Posted by kvizzle67

I wasn't aware there was a crossover between the tweeters and the 4" door speakers, looks like I will be getting the jl xd600/6 amp. Do the rear door speakers have tweeters or is it just a 4 inch speaker and also are there any speakers in the rear deck?

They are just mids. The rear deck speakers have tweeters, you could use those instead.

[kvizzle67]

bmw325i pmed you