JMII

After having my C7 for a few days and tweaking the EQ by ear I couldn't figure why it sounded alright at times yet so terrible at others. I started playing songs off my iPhone that I knew very well and it became obvious something odd was going on. Every song that was boomy and muddy at low volumes became flat and lifeless at higher volumes. So I did some research and found multiple reports of poor bass performance with GM's Bose's branded audio systems in various vehicles. To confirm I fired up Audio Tools with my calibrated microphone and sure enough: you could watch the frequency response shift as you turned the volume ****

Beyond stupid but it likely reduces complaints about distortion and blown speakers at dealerships. The system is actually pretty balanced frequency wise at mid volume so the audio engineers could (and did) try to make it sound good. However someone (likely in accounting) decided cutting bass at high volumes would save the crappy speakers from self destruction. Once they learned this was possible they then asked for a boost at low volumes to help overcome road noise. Of course is way easier to develop a software tweak then actually put in a decent components (like more expensive amps and speakers).

RacerRik

Your frequency response plot also shows why the system does not sound crisp and clear in the treble range. At about 10KHz the response drops like a rock falling off a cliff. That is some pretty poor hifi right there! I would be interested to see if that is intentional (as in the electronics are limiting the response) or if it is the mechanical limitation of the speakers. If you repeated the measurements with the treble set to max and the response looked good, i would say it was electronics. If the response still falls off like that, it is the speakers.

Avanti

Frankly, I find "sound quality" to be mostly in the ear of the beholders.

dave_2012_tt

When I first started test driving corvettes to find out what I would really like to have I found the 1lt stero to be farily sad. The one in the 2lt is OK. Just another reason I believe you have to go 2lt - the other reasons - HUD, dimming mirrors, front camera, etc.

RacerRik

Of course sound quality is in the ear of the beholder! But, objective data also has a place in determining the quality of a sound system. From JMII's frequency response plots above, one can see this system has many serious faults which will leave the experienced listener with a poor evaluation of the performance of this system.
1st is the drastic falloff of response above 10Khz which makes the music sounds lifeless and dull.

2nd is a cardinal sin for speaker designers where there is a significant peak at 1KHz where the human ear is most sensitive. This will cause listening fatigue along with a general feeling that the mid tones are unnatural and unbalanced.

3rd is the huge drop in bass response below 500 Hz at higher volume levels compounded with an excessive boost of bass frequencies at lower volume levels.

If we can assume JMII's measurements are correct (which I do since they correspond to what my ears tell me), then this system is a very poor sounding mess.

Some listeners will be tricked by the artificial bass boost into thinking the system sounds good because they are not used to high performance hifi systems which have tight, balanced bass response. Good base response is something that is lacking in most home and car stereo systems, so it is not surprising that most listeners have no experience with which to compare this Bose system. They hear an abundance of bass (muddy as it is) and they are amazed since they don't normally hear that bass.

Pisswilly

With all the complaints about Bose, why does GM keep using them?

RacerRik

Probably because some people have the opinion that a Bose system is upscale. And probably because it is cheap.

LT1 Power

I have the 3LT and with the top off and windows down, even with the sub woofer you cant hear nothing when driving.

JMII

Excellent overview of the "why" it sounds crappy despite the subjective nature of everyone's ears

My guess is the high frequency response is limited by speaker choice, GM is just being cheap with their choice in tweeters Low frequencies take big power and large drivers, which presents challenges in vehicles, so limitations are expected here.

However the fact that many people complain about the bass response in the C7 (and other GM vehicles with similar systems) indicates GM / Bose got it wrong. The extra 8" woofer in the 2LT and 3LT helps reinforce the bass frequencies but does nothing for true sub-bass response. As is the 10 speaker system peaks around 90Hz which is normally the crossover point between mid-bass (6" or 8") and true bass speakers (10" and up). 90Hz sounds "boomy" for sure, but not what I would call "deep" with any impact or punch. Clearly the system has no low end rumble at all. With a decent subwoofer you could run your crossover down around 60Hz and get amazing sound... well provided the mid-bass speakers could play low enough. Given the fact that the C7 has 10" mid-basses in the doors this system has potential, but it requires swapping out pretty much everything to fix it.

I get the poor response as sadly that is typical for almost all OEM audio systems, my beef is the fact that the Bose system is applying a volume based EQ curve (really just a down & dirty bass shelf). This makes audio playback inconsistent adding to everyone's confusion. The solution requires you to replace the factory amplifier as step #1. The catch is the amp is integrated into the infotainment chain (voice directions, vehicle chimes / warnings) so you can't just yank it out and splice in some aftermarket unit to the stock speaker wires like in the good old days.

BLUE1972

I have Nakamichi in my 85, 4pcs - P104 amps - 4 ch, Quart speakers and 2 -12" subs , 6 -6xx9, 6"+1" in the doors, 10 band equalizer.
The car was a display at a high end stereo shop before I got it.

Yes it can get loud, but it sounds great at any level. I keep it at 3 most times.



The Sony in the wife's wagon with Pioneer speakers sounds great.

I have a Pioneer in my truck and 71 = It sounds great , the Pioneer in my HHR sounds great - my friends C7 not so much....

Nakamichi P104 is 75 watts RMS per Ch.

69L79

IMHO, the stereo in my 1LT sounds fine once I adjusted the settings. Of course, I have tinitus in my left ear. So, what do I know. But, then again I didn't buy the car for the stereo system, more for the sounds of the motor/exhaust.

Keith Richards

The Bose in my 2LT sounds the best with the MP3, When I get in the wife's 18 speaker Hellcat with Harmon Kardon it is amazing for stock, at least IMHO. Keep having to look in the back to see if we have AC/DC riding around with us ;-) , our new Ram with Infinity is very good as well.

Tim0shel

Soooo awesome good job and you went with a great sub! I use to do SPL/DB Drags and Sound Q competitions and my Sound Q car I used Focal and Audison. I bet this does sound good but doubt I'll be out towards Dallas lol.

Raidercop

My 2019 3LT sounds great to me! Maybe I just don't know any better....

Shirl

My 19' Z51 coupe had an unimpressive Bose system. It was quite depressing since I had come from 650 watt Rockford Fosgate systems in my 4 previous cars with enough bass and settings to blow the windows out.. The Bose in my 19' Z06 Convertible, however, is MUCH better than the Z51 coupe was and I actually really like it. The speakers are right behind the seats (where they should be) and the cockpit is smaller so this greatly improves the sound quality and volume strength of the system.

mikebutson

My 2LT sounds awesome!

formie95

I just purchased a 19 1LT and it literally sounds like no bass at all. Ive played with the EQ turning bass up, leaving mid and treble in the middle, and it has absolutely no bass at all. Im not looking for rattling the car to death or changing heart beat bass, but it is all mids and highs at any volume. I saw the post for upgrading to 2/3 LT subwoofer and amp, and I may try that, but I would love to try and figure out why no lows. Ive seen other posts and comments say they have to much bass, and I just dont get it LOL.

Mad*Max

Most times I can't even believe there is a subwoofer in the car...my C6 had a better [slightly] sound system. In fact, the stereo in my Cadillac ATS is superior to the C7's

formie95

Im actually considering pulling the door panels off to see if the low door speakers are plugged in. I bought it used, and it doesnt appear the sound system was messed with, but I just cant believe how bad it is.

Raidercop

Maybe it's just my ears but my 2019 3LT sounds really good to me. I'm not a audio/sound geek so maybe others can tell a difference but it sounds pretty good to me. No rattles, a nice thump, highs/lows/mids. Maybe it's the kind of music(rock) I listen to? Idk...