shikataganai

anyone else have or heard of this problem?

'04 RX-8 Touring
- Bose stereo
- no changer or nav
- still under the 3/36 warranty
- no modifications to the stereo system

ever since i bought the car (5k miles ago) the center channel speaker has hissed. it's present during radio reception and while playing CDs, and is also present with the stereo off. it's even present with the car off and the key turned to Acc. i've sat in an '07 RX-8 GT with the same Bose system, and this newer car had the same noise present but only at a greatly reduced volume: even i had trouble hearing it with the engine off.

i'm a musician and somewhat, ok, very **** about these types of noises, and i can hear it plain as day over road and engine noise while driving down the road at 30. other people who ride in the car don't complain of the noise, and don't hear it over the road noise. however, i finally got my dealer's service manager to hear it by having him stick his head up near the windshield with the car off, key in Acc, windows up in a quiet parking lot.

the sound itself is a constant, high frequency diffuse noise, not as coarse or variable in intensity and frequency as static that you might hear on the radio with a weak signal. its frequency is unaffected by engine rpm (clearly, as it's present with the engine not running), and doesn't sound like alternator whine. i've had that before on previous cars, and alternator whine has a identifiable pitch that varies with rpm -- this doesn't, and is more like white noise. the hissing on my particular car seems to have gotten slightly louder since i got the car, but was definitely present initially. i am quite certain it is coming from the center speaker because covering the center channel speaker grille with one's hand silences the noise.

in any case, for those of you still reading, my dealer took this seriously, and i commend them for it: the car has been in their shop since Tuesday, i've been sent up with a rental car, gratis, and they have ordered a new headunit and center channel speaker. each will be swapped out in turn in order to pin down where the problem lies. with any luck the problem should be diagnosed, fixed, and the car back in my hands by Friday.

shikataganai

i picked up the car today, with a replaced center channel speaker and head unit. they said they left the original cd player in place, if that makes sense (are they separable?).

and the noise is still there. interestingly enough, it was also present on a RX-8 off the lot as well, although my original post notes that it wasn't the case with another '07 RX-8 that i listened to in boise...

next step: dropping the car off next friday so that the regional mazda rep can hear it. i'm starting to think it may be a common feature of the bose stereo. if so, then this is on suck-*** stereo indeed: background hiss, poor radio reception, muddiness when audiopilot is on, and far from linear. meh.

shikataganai

the plot thickens: i thought this new head unit sounded different -- volume levels 1 and 2 are already inordinately loud, for one -- and also noticed that the AudioPLT selection had changed to ALC. after cracking open the manual it looks like my dealer swapped out my Bose headunit for a non-Bose headunit.

time to go back and raise a stink, methinks.

jstkilntim

Interesting!! Keep us posted.

shikataganai

so it turns out that they didn't check the model number on the back of the headunit, missed the tweeters clearly marked "bose" in the a pillars, and thus checked off the "non-bose" box on the head unit replacement form. i saw the form myself.

furthermore, the local mazda rep came by yesterday and listened to the car. while they were able to get him to hear the noise, they then found out that the other 3 RX-8s the lot also make this same noise. (needless to say, their non-RX-8s don't make this hiss.) so apparently this is going to be chalked up as how the stereo is supposed to sound.

meh. i'm done fighting. i didn't buy the car for the stereo anyway, and at least they'll be replacing the head unit (again) with a new example of the proper, bose model.

climacus

This is normal. You have independently discovered what everyone have known all along: BOSE = garbage.

If you install real tweeters in place of the mid-range in the door, it sounds like a static storm.

shikataganai

so i FINALLY got this sorted out today after several more trips to the dealer. when i initially picked up the car the center console display completely freaked out when i turned on the headlights, scrolling through a psychadelic pattern that'd be pleasing on a iTunes visualizer but not so much for displaying useful information. i was all "wtf? how could they miss THIS?"

turns out that was a bent pin on the display connector, which they diagnosed and fixed in 30 minutes as i waited. now the car is back in my hands with a brand spanking new bose headunit, a new center channel speaker... and the noise is actually a bit quieter. it's still there, sure, but now not as prominent. it's a good thing this issue was finally resolved (if only partially and at the expense of many trips to the dealer) since my warranty is only a few hundred miles shy of expiring.

shikataganai

incidentally the system sounds amazingly awful when the non-bose headunit is mated to the bose amp and speaker setup. completely non-linear response, needless to say, horrible mismatches in levels causing the system to be REALLY LOUD immediately from volume levels 1 and 2 upward, and beaucoup static noise. even though the bose system itself is no catch as demonstrated amply through this thread it still sounds worlds better than the mismatched garbage.

RX82

I noticed that on my 8. I just got it a few weeks ago and it only took a day before I noticed it. I am also a musician and am very perticular about these things. I only noticed the noise when the car was off and the key was at acc. So I can't here it when the engine is running. So I really don't care that much.