Bose System

[XTREEME]

I just picked up a new 2005 T/B with the Bose system. As some of you know, the front speakers are good, but the rear sound is bad. Is it the speakers in the rear doors, or the power getting to the speakers from the unit that is deficient?

Thanks

[04TBEXT]

Their is a GM Service Bulletin #04-08-44-014B dated 10/19/04 relating to buzz type noise from rear speakers on for '04 & '05 T/B with Bose Speaker System (RPO UQA) and A4WD & AWD. And I quote, "Some customers may comment on a buzz noise heard through the rear speakers. This noise can be heard when the radio is on, volume low and while driving in 4AWD/AWD mode. This noise USUALLY occurs above 32km/h (20 mph) and is related to active transfer case operation." It goes on further to say, "This procedure will only correct the noise related to transfer case operation. It will not correct the speed sensitive whine type noise, commonly referred to as alternator whine."
Essentially this repair involves relocating a ground by constructing a new ground wire lead and attaching it to the brake booster bracket. The specifics are within the bulletin and can be performed at your dealership, if this bulletin is the cause of your concern. Hope it helps.

[XTREEME]

Actually, I was just referring to the Quality of the rear speakers vs the front speakers.

I don't have a buzz in them, its just that they don't give any quality bass like the fronts do.

I'd like to know if others have replaced the rear door speakers, with positive results, or if the amp powering the rear speakers is not strong enough.

[XTREEME]

One more question - I assume there are pre-outs on the head unit to allow me to plug an external amp for a rear sub? Just checking before I pull the head unit out.

Are there specs on this vehicle's Bose head unit anywhere on the internet?

[jdits7]

As far as I know there are not any preouts on the factory deck. There is an adapter that you can buy that will give you two preouts though. Not sure where to find it at, I will look around a little bit.

JD

[XTREEME]

As far as I know there are not any preouts on the factory deck. There is an adapter that you can buy that will give you two preouts though. Not sure where to find it at, I will look around a little bit.

JD

Any luck finding that adaptor? I see there is one out there by PAC called OEM-1, but it says that it does not work on 2005's ?

[jdits7]

That is the one that I was thinking about, didn't know it wasn't available for 05's though. Don't understand why not though. If I find anything else I will let you know.

JD

[bigwill]

First, the front speakers will sound more "bassy" because BOSE puts speakers in little "enclosures", so the front and rear speakers have different door sizes, shapes, and "enclosures", so you will get a different sound. Rear speakers are intended to be more "background", like surround speakers at home.

Bigger issue - No factory system to my knowledge will come with preouts - opens up competition. You wouldn't want BOSE systems if you could just add a better amp and speakers, and believe me, wouldn't be tough to beat the BOSE stuff. The odd thing about BOSE (unless they recently changed) is that instead of an outboard amp, like others use, each speaker has a small amp connected to it, so replacement is a huge pain. i.e. complete rewire, custom panels to mount the aftermarket speakers, etc. Apparently, the GM radios are a hassle to replace also, but for different reasons...

As far as preouts go, any high-to-low level adaptor will work, some better than others, so you can fairly easily add a powered sub, but replacing those BOSE speakers will be a big headache. Hope this helps, and yes, I used to work in a car audio shop.

[XTREEME]

First, the front speakers will sound more "bassy" because BOSE puts speakers in little "enclosures", so the front and rear speakers have different door sizes, shapes, and "enclosures", so you will get a different sound. Rear speakers are intended to be more "background", like surround speakers at home.

Bigger issue - No factory system to my knowledge will come with preouts - opens up competition. You wouldn't want BOSE systems if you could just add a better amp and speakers, and believe me, wouldn't be tough to beat the BOSE stuff. The odd thing about BOSE (unless they recently changed) is that instead of an outboard amp, like others use, each speaker has a small amp connected to it, so replacement is a huge pain. i.e. complete rewire, custom panels to mount the aftermarket speakers, etc. Apparently, the GM radios are a hassle to replace also, but for different reasons...

As far as preouts go, any high-to-low level adaptor will work, some better than others, so you can fairly easily add a powered sub, but replacing those BOSE speakers will be a big headache. Hope this helps, and yes, I used to work in a car audio shop.

Actually, I've since discovered that the reason the fronts "sound" like they have more bass to them is because of a subwoofer tucked under the center of the dash. So really, the front door speakers and rear door speakers are not much different at all. (Dohh!)

But this now makes me want to put a sub or two in the back area even more now (to "balance" out that bass feel).

The only thing that the local audio shops have available to hook up an external amp is an adapter which ties in from the speaker out feed from the head unit. I'm guessing I'd still need to pull power directly from battery for this type of setup.

[Tommy]

I'm guessing I'd still need to pull power directly from battery for this type of setup.

Just some FYI: I am not sure if this will apply to what you want to do but you can pull power from under the rear seat on the drivers side if it is more convenient. There is an 8 gauge wire that runs from the battery to a fuse block under the back seat. Very easy to hook up there, just loosen or remove the nut (depending on which connector you use) on the post, slip in the wire with the proper connector crimped on the end and your done. And don't forget to tighten the nut back up. :)

Be very careful because you can ground out the power wire very easily in that place, its very close to the metal rear seat mount. I taped all the metal that was near the wire when I did it.

I like to use these:

http://www.tbecentral.com/images/forumpost/closed.gif

Instead of these:

http://www.tbecentral.com/images/forumpost/open.gif

-Tommy

[rt9bil]

Alrighty, lets clear somethings up hear. Unless they have changed the bose system up, there is one amp located above the passenger side rear wheel well. The front door speaker are made to produce more bass. The rears aren't.
The good components to any system should have Highs/mids/low speakers. These all working at the same time are supposed to produce good, clear sound. It really doesn't matter where u put the low(bass) speakers b/c the sound is so deep that its distributed or heard equally throughout. As for the sub in the console...there is none. If u have a Bose sys. in your TB u only have 6 speakers. If you guys r looking to add an amp to the oem headunit, check out pac-audio.com, product # C2A-GM24 lets u do it. I think it works for all year, if i'm not mistaken.

[XTREEME]

Alrighty, lets clear somethings up hear. Unless they have changed the bose system up, there is one amp located above the passenger side rear wheel well. The front door speaker are made to produce more bass. The rears aren't.
The good components to any system should have Highs/mids/low speakers. These all working at the same time are supposed to produce good, clear sound. It really doesn't matter where u put the low(bass) speakers b/c the sound is so deep that its distributed or heard equally throughout. As for the sub in the console...there is none. If u have a Bose sys. in your TB u only have 6 speakers. If you guys r looking to add an amp to the oem headunit, check out pac-audio.com, product # C2A-GM24 lets u do it. I think it works for all year, if i'm not mistaken.

So what the heck are those guys at Bose trying to tell me then? That is where I got the info from. I just assumed they were telling me the truth. But since you wrote this, I took a closer look and listen around my vehicle, and sure enough, I can't detect anything useful coming from under the dash area anywhere.

So then back to my first thought, the rear speakers are junk. I think they would be worth replacing, but decent aftermarket ones run at 8 ohm, and I think the Bose stuff runs at 2 ohm. That would create extra heat in the H.U. since the Amp is only powering the front door speakers, right?

[bigwill]

So what the heck are those guys at Bose trying to tell me then? That is where I got the info from. I just assumed they were telling me the truth. But since you wrote this, I took a closer look and listen around my vehicle, and sure enough, I can't detect anything useful coming from under the dash area anywhere.

So then back to my first thought, the rear speakers are junk. I think they would be worth replacing, but decent aftermarket ones run at 8 ohm, and I think the Bose stuff runs at 2 ohm. That would create extra heat in the H.U. since the Amp is only powering the front door speakers, right?

Actually, aftermarket speakers in car audio are typically 4 ohm, and I'm not sure about BOSE, but definitely not 4 ohm. I actually thought they were much higher, like 10-16 ohm. Again, I may be wrong about the amps on the speakers as they used to be, but either way, the amp is not in the H.U. If you use 4 ohm speakers and the amp is designed for 2 ohm speakers, all the better for the amp, you just won't get much power. I would check with Crutchfield or a local stereo shop to find out exactly where the amp is. If it is a separate amp that powers all 4 channels, then just replace the speakers and be done with it. Another problem to consider, though, is that factory speakers typically will give you more bass, though muddy, and aftermarkets will give you a cleaner, well-rounded sound. It would be kind of silly to have better speakers in back!

[bigwill]

[/QUOTE] only thing that the local audio shops have available to hook up an external amp is an adapter which ties in from the speaker out feed from the head unit. I'm guessing I'd still need to pull power directly from battery for this type of setup.[/QUOTE]

Right, all the adaptor does is take little power and signal from the speaker wires, cut the power, leaving (most) of the non-powered signal to go to the amp. You still need power, ground, and a 12 volt turn-on lead to fire up any amp.

[rt9bil]

This whole Bose thing kinda sucks, b/c you think by spending the extra money and getting the Bose sys. your doing something good. I have researched this topic for awhile now and realized that we're pretty much screwed. The thing is that all the Bose equipment is interrelated. Bose is quite unique in the way they design their stuff. Basically you can't just swap out the speakers w/o getting a new headunit, b/c of the 2 ohm thing. It doesn't sound good at all. Without the Bose headunit you can't use the amp as well as losing other functions like steering wheel controls. Truthfully, theres only 2 options:
1) Drop the big $$ and get a whole new system (H/U, speakers, amp, wires etc.).
2) Keep the Bose sys. and buy the adapter to add an amp and sub.

O' yeah, to my knowledge the only chevy vehicles w/ a sub in the console are Tahoe, Suburbans, and i think Silverados.

[XTREEME]

This whole Bose thing kinda sucks, b/c you think by spending the extra money and getting the Bose sys. your doing something good. I have researched this topic for awhile now and realized that we're pretty much screwed. The thing is that all the Bose equipment is interrelated. Bose is quite unique in the way they design their stuff. Basically you can't just swap out the speakers w/o getting a new headunit, b/c of the 2 ohm thing. It doesn't sound good at all. Without the Bose headunit you can't use the amp as well as losing other functions like steering wheel controls. Truthfully, theres only 2 options:
1) Drop the big $$ and get a whole new system (H/U, speakers, amp, wires etc.).
2) Keep the Bose sys. and buy the adapter to add an amp and sub.

O' yeah, to my knowledge the only chevy vehicles w/ a sub in the console are Tahoe, Suburbans, and i think Silverados.

I have to agree with you about the whole Bose (or as some say "Blose") setup. Very disappointing, especially to those of us who may have surround sound systems in their home and are used to hearing quality audio elsewhere.

I also have to agree that those rear speakers (where they are located) are a waste of time to worry about. They are so far away and blocked from the drivers ears that it would not really be worth the effort, even if the sound quality was reasonable from an aftermarket, which is debateable as well.

I'll have to take a serious look at this Pac-Audio interface made for plugging into Bose systems to provide a preout for an amp. Its the OEM-1 about half way down the page:

http://www.pac-audio.com/products/oem1.htm

[T-BlazinOn22s]

If you get a good head unit, it will have built in crossovers in it. Then all you have to do is set the high-pass frequency to 80hz or even 120hz which will not allow frequencies lower than set to pass through the speakers. Which in turn will allow higher volume with much less distortion, if any. The Bose speakers will handle enough power to get great sound at high volume as long as you eliminate some of the bass coming from them. If you have subs, you won't need bass to come from the factory speakers anyway. Hope this helps someone. -Later, Bill-

[02EnvoySLE Guy]

If you get a good head unit, it will have built in crossovers in it. Then all you have to do is set the high-pass frequency to 80hz or even 120hz which will not allow frequencies lower than set to pass through the speakers. Which in turn will allow higher volume with much less distortion, if any. The Bose speakers will handle enough power to get great sound at high volume as long as you eliminate some of the bass coming from them. If you have subs, you won't need bass to come from the factory speakers anyway. Hope this helps someone. -Later, Bill-

That's my only complaint about the factory non-bose speakers in mine. There's entirely too much bass, too little mids or highs comming through. I haven't been able to manually tweak it too much to improve the situation without getting rid of almost ALL of the bass output.

[struff]

I have to agree with you about the whole Bose (or as some say "Blose") setup. Very disappointing, especially to those of us who may have surround sound systems in their home and are used to hearing quality audio elsewhere.
And even more dissapointing is when you're supposedly "upgrading" from an old TB with a non-Bose system to a new TB with a Bose system. In my old TB, in addition to having the various EQ presets, there was also a Midrange setting. But the new TB, with the WAY too expensive Bose system, doesn't have the preset EQ settings and doesn't have the Midrange settings. WTH is up with that?!?!?!?!?!? The new Bose system sounds like crap! It even sounds worse than the Kia loaner car my dealer let me use yesterday...a KIA...sounds better than my TB's Bose system!!!!!!!!!

[jimmyjam]

I created a page for how I put a subwoofer in my 2002 TB with "premium" bose system here (http://home.earthlink.net/~jimmy_jam/trailblazer/)

Heres a summary:
There is an amp in the back of the car.
The speakers are 0.5 ohm.
The signal going from the HU to the amp is constant volume
The amp volume is controlled by the class2 databus
Without a converter box, you're not going to be able to hook up an amp

MM i'm adding some Polk components as soon as I build some mounting plates for my door. I can't wait to show them off :D

[luvchampagne]

Does anybody know if you can replace the stock Bose Amp with another Bose amp? There are frequently Bose amplifier for different vehicles on ebay and I wondered if:
1. Can you replace the stock bose amp in the TB with a different Bose amp from another vehicle? The one I'm thinking about is a 5 channel amp out of a Mercedes?
2. Will it help?
Thank you
Roy

[ScarabEpic22]

Does anybody know if you can replace the stock Bose Amp with another Bose amp? There are frequently Bose amplifier for different vehicles on ebay and I wondered if:
1. Can you replace the stock bose amp in the TB with a different Bose amp from another vehicle? The one I'm thinking about is a 5 channel amp out of a Mercedes?
2. Will it help?
Thank you
Roy
Highly doubt it man, sorry. Im pretty sure each Bose system is different for each manufacture and even each model by that manufacture.

Probably wouldnt help anyway.

[Dave]

Does anybody know if you can replace the stock Bose Amp with another Bose amp? There are frequently Bose amplifier for different vehicles on ebay and I wondered if:
1. Can you replace the stock bose amp in the TB with a different Bose amp from another vehicle? The one I'm thinking about is a 5 channel amp out of a Mercedes?
2. Will it help?
Thank you
Roy

I'm pretty sure they will be GM specific. Mercedes probably paid them bigger bucks. Right now I'll just be glad to get rid of rear speaker whine.

[gallai]

Some aftermarket amps can accept speaker-level inputs, ie you don't need to buy the PAC adaptor.
Of course you will lose quality either way... "de-amplifying" an already amplified signal just to amplify it again... :crazy:

I actually replaced my Bose h/u with an Alpine+ipod combo and kept the Bose amp+speakers.
It sounds better but is ugly. The bose h/u may sound bad but integrates so nicely in the dash, nothing beats it.

to sum it all up: we are all screwed :)

Greg

[BUC NASTY]

maybe

[logo]

you will need to updat the amp for rear i did its so good the front are you bass speakers thats why thay sound so good:D

[JFSebastian]

The regular sound has too much bass too. But I didn't go with Bose because of the junk I've heard for their home systems.

[WhiteTrashEXT]

There is a wire harness for your factory Bose but there is something else to keep in mind.
Do you have onstar? if so then be careful which harness you buy. The onstar wont work with it. I learned that the hard way.

Im not sure of the part number but I found one on ebay and the company had both harnesses (w or w/out onstar).
I bought an aftermarket harness for my in dash dvd player and for the onstar it was like $180 I think. But that was 2 years ago. If I can find that part number for you Ill post it.

[WhiteTrashEXT]

Try this!

[DaveH]

I've got the Bose system in my '02 (build date April '01). I've notice lately that if my TB is parked facing into the sun for awhile and I drive away, turn on my radio, my right side dash tweeter does not sound clear. It sound like the speaker has a rip or tear in it. After a while the blurry noise goes away and all is well again. Anybody have any thoughts. Also, can anyone inform me as to how to access the tweeters in case I have to replace them? Thanks in advance for your help and advice.

Dave