I don't even know if what I'm asking is possible, but if it is it will be the least expensive possible solution (if it would even be a satisfactory result).

What I would like to do is be able to get into the service menu on my stereo, and flatten any sound equalization the stock head unit is doing.

The reason is, even with the treble, and mid both set at -5, the system is putting out inordinate amounts of over trebalized ear piercing sound. As an aside, even with the base turned down the speakers are sort of boomy too... No matter the master volume.

This stereo is quite possibly the worst factory system I've ever heard. I can literally only listen to it for about 30 seconds before my ears start to bleed. Hard to believe the factory tape deck in my 85 Accord I had ages ago was superior to this car's stereo in just about every way, except having far fewer speakers...

I cannot remember where I found it, but I did see somewhere on this forum someone posted how to get into the GS's stereos service menu and be able to do this. Can't seem to find it now, and not sure if it would even apply to my car.

 

Factory stereos are tuned to deliver what the manufacturer believes the average customer will "want" to hear. This means that when you set your HU to 0 settings, it isn't a truly flat signal. You would have to adjust it with an RTA to determine what a true flat setting would be. This is why many people like JL Audio's CleanSweep OE integration system, as it uses signal summing and then sends a true flat signal to the amp. Mind you, you would be installing aftermarket to power your speakers if you used this. Really not a good work around (that I know of) when trying to make the OE system sound any better.

 

I'll have to look into something like that when I'm ready to spend money.

Still don't understand why the factory systems cannot put out a clean signal... What's the whole purpose of the bass, treble, and mid adjustments if some engineer in Japan is building biases into the system...

Just ranting here. But first they build an HVAC that is integrated into the CD changer. And now in order to upgrade the system I have to get a signal processor to clean the signal up..

I'm really starting to not understand the logic of this company.