I've done it in other cars, but it never seemed worth the work. For a sub, I don't think the diff between the low-level signal and the speaker-level signal is that big a deal. I mean, I know it's audible, but if you're keeping the Bose stuff, it must not be that important, right? : )

I did a TSX where we retained R door speakers off of the OEM amp and ran F and sub off of a new 4-channel. Big PITA, not worth it at all. But it worked.

 

How much more qualified do you think the poor guy at the wire factory was than you are?

Cut, strip. Not that hard, eh?

 

el_duderino, I’ve been reading some of the g35 driver forums as well as the Car Sound and Performance forums. I'm confused about the outputs from the HU to the Bose power amp (2005 G35 sedan). Other osters have stated that all (most?) Bose systems have flat outputs from the head units and that all the equalization is done in the power amp. In addtion, the volume, tone controls and other functions are controlled by sending a signal from the head unit to the amplifier over a message bus and the head unit itself has a fixed voltage output. By that I mean the audio signal is there, but the head unit output is not controlled by the volume control, but a signal is sent to the amp to control volume, etc. i.e. The volume and eq adjustments are done in the amp.
If this is the case, it seems that tapping a signal between the HU and amp would give a fixed level audio signal. Therefore, how you would control a third party amplifier if you wanted to replace the Bose amp and keep the head amp without tapping the signal off the Bose amp outputs. This would seem the only way to keep the head amp and steering wheel controls. It may be that different Bose models from different years are different in this respect, but I've seen multiple confirmations of this on different posts, while at the same time seeing other posts where the HU outputs are used to power a new amp (not the amps outputs and a level converter). I'm confused. If you or anyone can shed some light on this situation, I would appreciate the information. Thanks

 

If you tap into the signal coming out of the Bose HU and plug the signals into an aftermarket amp, you can still control the volume, trebble, bass, fade, & balance using the stock HU. You also don't lose the stock steering wheel controls. The only thing that's lacking is how well you can fine tune the sound using the stock HU as compared to an aftermarket HU with more features.

 

Yes, you still have control of the volume, etc. I have done it myself. The amp may do some equalization, but the HU still controls the volume/bass/treble/fade/balance/speed volume control, no if's and's or but's.

 

Thanks for the info Espresso. So where did all this information about about a fixed level HU output come from. Some posters said they actually measured the levels and they were fixed. Manville Smith from JL audio when discussing the cleansweep responded to these posts and agreed that, in at least some cases (maybe all), the system EQ occurs in the amplifier and the head unit output is not controlled by the volume control but yhe amp output is. It seems some people have used the outputs successfully, while others claim it's impossible. Both sides seem to very knowledgeable about car audio, thus the confusion.

 

Some GM Bose systems use fixed level outputs. That's where it comes from, along with your confusing (to me) use of the terms "flat" and "fixed".

Flat to me means non-eq'd

Fixed means unchanging.

Most people who have some knowledge of car audio are self taught and have no other education in it other than what they know, so they tend to identify with being knowledgeable and are very defensive about it. This is one reason why many experienced installers are near-total jerks. Lots of those frequent the car audio boards. They often don't have a scope or use a real time analyzer, and many don't understand audio electronics too well, like the difference between true balanced and single ended signals.

I am sometimes wrong. But I have 18 years with retail, manufacturing, product development, and product marketing. I ran the tech support department for a large 12V product manufacturer and have a US Patent on security features (if you have a Viper, Clifford from the last few years, or Python, you have my patent working in your alarm). I am a past chair of the CEA's 12V Education Committee, a past member of the MECP Commitee, and a contributor to the original MECP Study Guide. I've written about half a dozen articles for Car Audio and some more for other books.

Butr I'm still wrong sometimes.

 

Thanks to both khsonic03 and el_duderino for the additional information. I thought that I had used the terms flat and fixed as you described them, but obviously what was clear to me was not clear to the rest of the world-sorry. The bottom line as I see it seems to be that in a 2005 G35 sedan the outputs of the Bose HU can be tapped off before the Bose power amp and used to drive a new power amp with all volume, base, treble etc controls intact. Am I reading this right? Thanks

 

P.S to the above post. To go directly to a new power amp I believe it needs to accept balanced inputs or you need a differential to single ended converter of sorts. Thanks again.

 

Correct. ( i say that like I know something, when really I'm just repeating what I recently learned from a couple of older threads and el_duderino in this thread.)

 

It's a little more complex than that, but yeah.

For instance, the DLS CA41 is supposed to NOT have balanced inputs, but it works with the balanced outputs of true-AC HU's just fine with no noise.

The JL "slash" amps seem to work pretty well this way. I'd expect the xtants that are based on the older gear to work well, but the newer MTX xtants I don't know.

In my experience the Diamond amps hate it. I don't like them anyway.

I sell DLS and really like all their gear so far, but it's hard to find, so I'
d feel pretty confident in JL "slash" amps personally. Owned one for a while and liked it.

 

Guys, i have a question:
i want to do a 10w7 with a jl500/1 running that and then i want to do a jl 300/4 and replace the front components and rear panel coaxials using a clean sweep as well (then just turn off the rear speakers competely)...the guys at Motor Music told me it would be the best setup if i want to keep the stock HU...PLEASE ADVISE!!!

 

oh just to make sure you know i have an 05 6mt with the bose system

 

This is going to be a long post, it seems my posts are always long, probably because I'm bored at work.

I'm not sure what "best setup" means.. what is it being compared to? I'll tell you my situation and where I am now from lots of reading and posting and getting pwned and crying in my sleep:

I was CURIOUS what it would take to get a sub in my car, and I was out and about burning expensive gas and I stopped by tweeter. I ended up walking out with a quote for an entire system reword for $3000. They based the entire system on a CleanSweep. Their plan was to replace the front speakers with new component sets, kill the rear speakers all together, and use the rear speaker outputs as the feed for the subwoofer. They quoted me Focal components, an Audison 4 channel amp, cleansweep, dynamat, one of those JL stealthboxes and a JL sub.

The solution you and I were recommended seems to be the standard cookie-cutter "I have no idea how to do an audio upgrade using an OEM head unit" answer. While the solution would WORK just fine, and probably sound great, it has it's downsides. With their solution I would have lost my steering wheel controls, I would have had to use a remote volume **** mounted somewhere in-reach of the drivers seat, and I would have lost my rear speakers (although I'm not sure even know if I care if I lose those). If these downsides don't bother you, then it's a viable option to consider.

Personally, I love my car, it's the second car I've ever owned and it's the first one that's in my name that my parents had nothing to do with (drove to the dealer, said I want that one, drove home with it). Needless to say, I'm super protective of her, and I hated the idea of losing my steering wheel controls and losing the stock look and feel just to get a better sound system.

So I started reading on here and thanks to a lot of great people and good posts (with a special thanks to el_duderino), I realized that there are other options.

You can read through this thread and others like it and determine what those other options are, namely using the virtually flat/non-eq'ed signal from the HU (before the Bose amp) as the source feed to an aftermarket amp (with all the little things necessary to complete that included).

Whether this is a BETTER option or the BEST option I think is a matter of opinion. My opinion as it stands right now is that the Cleansweep is overkill and 1.) adds too much complexity and 2.) makes me lose too much stock look/feel.

So you asked for advice and mine as it stands right now is, go with a setup as described in this thread, rather than the cleansweep.

I went by borders and picked up some 12v books so I can get a better handle on how this stuff works at an electrical/ohm's law/grounding sorta level. Lots of people don't care to know stuff to that sort of degree, but I find it fascinating to know as much as I can about as much as I can.

 

amthar, check out the12volt.com it is a great site where you can learn alot about the basics of car audio. Another great site is bcae1.com. Have fun with that for a couple of hours. You'll learn alot.