cmb13

Question about stereo mod. I know a lot of you guys are changing the speakers with these Eclipse speakers. How many Ohms are they?

Reason I ask is that I just went to a stereo store and the guy told me that because I have a Bose unit, I can't change the amps or speakers. He said Bose uses 1.5 Ohm speakers, whereas all other speakers are 4 or 8 Ohms or something like that. Says I'll blow the head unit. True? Another stereo installer from a different store said the Bose speakers, at least in the C5, have built in amps right in the door, or something. I'm not sure what to think.

shopdog

The stereo store guys aren't up on the C6. Unlike previous years, the speakers in the C6 are plain old nominal 4 ohm speakers, as is standard industry practice. No amps built into the speakers either. The 10 inchers in the doors are kind of special, because the mounting is so shallow. But you don't need to change them to improve the sound of the system. The worst offenders are the 3.5 inchers in the doors, and there's nothing special about them. They're just plain old paper cone 3.5 inch 4 ohm speakers. The Eclipses will drop right in as replacements.

Do note that the rear speakers in the 1SB cars are wired in parallel, ie in mono. If you want them to be stereo, you're going to have to add a tap between the HU and amp with a PAC C2A-GM24 adapter and add a separate amp for the rears (stock amp still drives the fronts). Some speaker rewiring will be needed too in order to separate the channels. You'll only need a 25 watt amp, don't go crazy unless you're building a competition boombox.

Be aware that the front/rear fader on the HU won't work anymore if you do this. The HU only outputs 2 channels. It commands the Bose amp to *simulate* a rear channel via HU fader control. That won't work anymore if you add a separate rear amp. Just run the fader to all front and control the F/R balance with the screwdriver adjusts on the PAC adapter.

Of course you'll want to disconnect the center dash speaker completely in order to restore the stereo sound stage. It is fed with mixed mono from the Bose amp, and really screws the stereo image.

cmb13

Thanks, Shopdog. I always trust your replies. I know you've answered speaker questions for me before. I just wanted to make sure I wasn't about to do something stupid with the stereo. It seems these 'experts' at the local audio shop need a little educating. Funny thing, this shop bills itself as high end, expert, the best around. The guy wouldn't even let me talk to the installer. Shop is Sound Advice, Yamato Rd in Boca.

SteveL2

Any idea as to why?

shopdog

I'm told that this is a Bose "feature", along with the mixed mono center dash speaker, that's intended to make the sound be exactly the same in the passenger seat as in the driver's seat. Well, duh, mono will do that, but it sure destroys the stereo imaging.

EatRice

The guys that told you the head unit will blow don't know much about audio let alone the C6. Higher impedance causes the amp to create less power. So if you installed a 4 ohm driver on a amp the is designed to power a 2 ohm driver the amp is going to make less power. Now if you put a 2 ohm driver on an amp that is designed to run in 4 ohm it is very possible it would blow.

shopdog...good info on the C6.

I do believe the idea behind the mono the rear speakers is to create a rear fill. Stereo is left and right only...there are no rear speakers or center speaker in stereo. Putting the rear speakers in mono will help keep the sound stage to the front of the car while still adding a music presence in the rear of the car. From an audiophile point of view all the music should come from the front. Example...when you attend a concert does any of the band ever play music behind you? No they are all together on a stage in front.

I have not messed with or even listened to the stereo in a C6 yet. But from what shopdog describes it should sound alot better then the C5 system.

Crystal Vette

Great info, ShopDog. I think you mentioned in another post how to remove the door panel. Do the clips break easily? I will do a search for your other post again.

mtaylor72

FYI - be careful if you start to mod the Bose (blows) sound system. The OEM speakers are so bad, that they engineered a serious high frequency EQ into the head unit. It slopes up 5 volts (aobut 16 db) from 2K to 16k. So.......when you put a decent amp and speakers in, the high end will tear your head off. There are some solutions that work well, but it will be more expensive than you expect.

If you have questions, let me know since I have been through the ringer on this one.

cmb13

So did you keep the head unit and change the amp and speakers too? Let me know what you did and what your solution was to the problem. Thanks.

mtaylor72

To qualify my comments, I have been designing, selling and marketing sound systems for commercial, concert, church, home and home theater applications for about 25 years....so I know something about audio.

Yes, I kept only the head unit....everything else is new/upgraded.

Put MB Quart 4" coax in doors top, 6.5" coax in rear position (stereo) and found a set of inverse magnet, kevlar cone woofers for lower door position. Then put Apline 450 watt 4 channel amp on rear deck.

Use a pair of high quality transformers to take bose speaker level output down to line level, then feed the amp.

The MB Quart coax speakers have a 0, -3, -6 poistion switch in the crossover that helps a ton with the excessive high-end. Also have to run the treble control all the way down for some sources. There is a new device from JL Audio called Cleansweep that I am going to add to handle the EQ a little better, but the sound is very good now (and I am picky...).

I also put a ton of acoustical materials in the doors to stop rattles and vibration with the new system. The installer I used is very good and could most likey walk you through the install if you need advice.

cmb13

Very helpful, thanks!