06 Monsoon sounds like crap

[Chronosnight]

First post, just got a 06 gxp with 55k miles the other day, so far I love it. Very small list of complaints, one of the major ones is the sound system. As far as I can tell everything is working alright, settings are good, speakers all work, but the sound quality is horrid. There isn't any popping or hum or anything it just doesn't sound good and gets worse the louder it gets. Is this just not a very good audio system or do you suppose something is wrong? My girl has a Mazda 6 with the Bose system and that sounds amazing, I had a 08 Scion XD with the updated system and that sounded pretty good.

Also I need some way to hook up my Iphone to the setup, I see from browsing around here that there are a few mods I can put on the back to tap into the XM aux, but after all the parts wouldn't it make more sense to just buy a new nice pioneer HU with Ipod controls built in? Also if I go that route will I be able to control that new HU with my steering wheel controls? Or does that depend on the model?


Thanks!

[tod1d]

the monsoon system could use a sub woofer installed behind the passenger side tail light but other then that its more then enough for me, I had a completely after market system in my last vehicle so I know what a far more powerful system sounds like

if you replace the stock head unit you will need a security bypass module and loose the steering wheel controls

[Chronosnight]

So these don't work??
PAC SWI-PS - Pioneer and Sony Steering Wheel Radio Control Interface

[rainmkr2]

I am a recent GXP convert myself. My old GTP had a completely aftermarket system that I put in myself and was (am) VERY happy with. My GXP sounded like crap to me as well. I am currently in the throws of converting stuff.
This forum article was a big help: http://www.grandprixforums.net/facto...loc-32533.html

So far I have I found that one of the door tweeters had fallen apart and I think this was a big part of my problem. I replaced just the tweets with JBL GTO18t's. They are little too efficient however but much smoother than the OEM's. I have also added a couple of 10' subs and 400 watt amp. I tapped into the Monsoon Harness with a MTX RE-Q 3 using the speaker level sub signal going to subs in the trunk. Added caps to the existing subs (still playing with the value but I think I'm above 80Hz now maybe like 100Hz or so) Sounds pretty good, but not as good as my old GTP. I found that running the EQ levels on the head way down on the negative side works the best and is more like a "flat" response. This combined with the RE-Q seems to flatten things out in terms of the bass response. MY Monsoon system seems to have a high noise floor IMO. Next summer may see the whole Monsoon amp removed, a 4x line driver and all new speakers and speaker wiring all the way around. I used headphones with the line side of the system (before the amp) and it seems pretty clean and noise free, so my guess is that the Monsoon amp is putting out a lot of noise (what you hear when the volume is at zero).

Big problem is I like the integration of the head unit (HUD and stuff), the steering controls are and have been a non issue for some time, I did that in my 1998, and it has worked great for many years with a Sony head unit. There is also a PAC's unit for the chimes, On-Star and such.

Interested in your thoughts.

[matt5112]

If you have to use EQ then you did something wrong.

If you must use it, negative gain only.

What exactly are you looking for?

As long as you keep stock positions you'll have difficulty getting much better.

Unless you wanna go all out with sound processing like I800.

[rainmkr2]

If you have to use EQ then you did something wrong.

If you must use it, negative gain only.

What exactly are you looking for?

As long as you keep stock positions you'll have difficulty getting much better.

Unless you wanna go all out with sound processing like I800.

Negative gain as in at the head unit (bass, mid, high). This also reduces the loudness (loudness as in added Bass and Treble at lower volumes to compensate for the decrease in speaker sensitivity as it relates to lower voltage).

Problem with GM systems is that they "EQ" for the vehicle in the head unit. Can't remove it unless you post process. The other problem is that they use a goofy loudness curve. It boost the frig out of the bass at mid volume and rolls it off hard as you increase the volume to protect the less than spectacular speakers they provide.

The RE-Q helps this, but what I found was that it was not enough bass de-emphasis at mid volume. So by moving all the head units EQ levels down to negative values (in effect lower the gain) the hump is moved to a lower voltage level where it is more helpful.

You are right about one thing, I am doing something wrong, I'm trying to keep the stock head unit. My goal it to get it where I can live with it, but you know how that goes. Once you start changing stuff it is hard to stop. That is why why I ended up gutting my GTP and putting in all aftermarket stuff from front to rear.

[matt5112]

I know there are systems that "counteract" the factory EQ but the loudness curve you're kinda stuck with.

Good luck!

[rainmkr2]

The MTX RE-Q 3 does just that, but they don't let you pick the voltages where it first removes bass then a span before it starts to add bass back in. If a line driver is applied before the RE-Q unit, it is possible to slide things around, but there I go again adding more stuff. A good 4 or five channel line driver costs more than a decent head unit. The OEM head will probably be on my work bench in the spring (sitting next to the 5 others I have pulled over the years).

Check out the link to the MTX RE-Q, they also make a 5 channel version which can be used to feed a 4 channel amp and a sub amp. This setup would probably work best since the bass correction is applied to all channels not just the sub channel like I've got mine hooked up right now.

Another interesting thing, all the speakers I have check ring out at around 4 ohms. Maybe these newer Monsoon systems don't use 2 ohm drivers like I've read the F body and Bonneville used. Guess it does not really matter, the GM speakers are so inefficient, a typical 91db after market speaker that is 4 ohms will probably sound louder than the stock driver at the same voltage. 3db up in SPL @ 1 meter 1 watt = ~ 2x the sound energy output.

[matt5112]

yet 1 dB is about as small a difference that we can "hear"