What I have noticed, is that the factory system, when turned up....usually makes the bass not raise in volume..(i have 2 10" subs in my trunk).
basically around 14 i hear a good level of base and treble..and then at 25-26, the treble is much louder than the bass.....
i'm under the impression this is a safety feature so that people do not blow out their speakers with bass...

my question:
is the the doing of the headunit or the amplifier...
i'm gonna guess headunit....
also...would changing my bose amplifier do anything if i didn't replace the headunit..is it worth it?
thanks


Mitch
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My non-BOSE headunit does not exhibit the same behavior. Perhaps it is the amp.

At 10-12: Sounds good
At 14-16: Sounds better
At 20-25: Sound f%^& fantastic! [img]/w3timages/icons/laugh.gif[/img]

Take care!

BLKSNAKE - '04 G35 Coupe
Check out my hidden sub! [img]/w3timages/icons/laugh.gif[/img]

 

Its the amp. I believe there is a protection circuit that kicks in to prevent the subs from getting loud enough to distort. I hated that.

 

If i wanted to replace the amp, what would be a suitable replacement for the stock speakers? Would the install be easy if i'm somewhat audio savvy?

thanks


Mitch
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Unfortunately, the stock bose speakers have a impedence load rating of something like .5 or 1 ohm. Basically, this means any amp you connect will have a very hard time being compatable with those speakers. If you are going to change the amp, then you are going to have to change the speakers as well. Doing one without the other will cause compatibility issues regardless of the amp you buy.

 

I believe JL Audio's "Slash" series amps can drive the BOSE speakers safely (I overheard a installer tell another customer while having work on my car performed).

I agree with g35audioman and would change the speakers as well.


BLKSNAKE - '04 G35 Coupe
Check out my hidden sub! [img]/w3timages/icons/laugh.gif[/img]

 

The jl Slash amps probably could since they are rated down to 1.5 ohms. Even then, i wouldn't do it. What is on paper and what occurs in the real application are completely different. Bose has a history of making it tough to change their systems out. I wouldn't be suprised if you still ran into problems with the JL amp. The varying impedence load of the speakers could cause the amp to malfunction. Then your deck could malfunction and so forth. Not worth the headache for a slightly better sound upgrade. Your speakers will be the limiting factor with a new amp. Change them out! [img]/w3timages/icons/smile.gif[/img]

 

I tested the factory 6.5's. They test at a minimum DC impedance of 2.0 ohms (that means, the nominal operating impedance that you'd see on paper is higher). The tweeters, 4.0. I have not removed the 6x9s to test those. Someone else had done more extensive testing and determined that this particular Bose system does not utilize weird impedances.

Most amps will have no trouble driving speakers even at the minimum 2 ohms, because your typical 2 channel amp is designed to drive a speaker bridged at 4 ohms. In stereo mode they're typically stable to 2 ohms per channel.

I ran the stock speakers off of a Crossfire amp for a couple weeks. No problems at all. They responded just as well as they did when they were connected to the Bose amp. The Crossfire amp showed no signs of being overworked. In my "careless youth" I've overdriven car audio amps before. Not that I'm recommending overdriving an amp, but the result is usually that they just overheat and shut down due to a thermal protection circuit. I'm still running the rear speakers off that crossfire amp, but I replaced the fronts for sound quality reasons.

Now, as far as the bass volume goes ... what I see with my setup is that it's relative to the BASS setting. If you crank the bass up to +5, it slides a lot depending on what you set your volume at. If you set it to 0 the bass stays pretty linear with the volume. So, tune your system with the bass at 0, or perhaps even less.

-- Rob

 

not the case with me, i had to turn my bass down to -5 and it was still loud, i didnt have the premium bose system though, so maybe thats it...

 

Very informative post Rob. I was not aware that the impedence of the bose speakers were fairly normal. Thanks for clearing that up.

 

when i remove the stock premium bose, i measure the impedance and yes i also got 2ohm for the front midbass. Didn't measure the tweeter.

g35mt

 

thanks for all the info guys.....my system is still loud..dont get me wrong..but i just see the disproportion at times...i usually have my bass at -5...and its ok..so i am now putting it at like -3 or -2..and it pounds


Mitch
2004 G35C AT
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