Factory amp question. Has gain control?

[anarchyx34]

Almost finished with my 9-3's audio install. So far I've replaced the head unit, front speakers and door speakers. I made my own adapter for the DIN plug and it works well. Sounds way better than before but needs a few tweaks.


First off the dash speakers are getting too much bass. I noticed that the factory dash speakers are very stiff which probably dampens low frequencies, but the Kappas i put in are quite sensitive. My head unit dosent have a high-pass filter (just about the only thing it dosent have) so I may just install simple bass blockers to cure that.

The other issue is that the door speakers arent loud enough. I put in CDT Audio 6.5" woofers (they're gorgeous) but they're apparently a little thirstier than the factory drivers. They sound clean (dont sound like the amp is under-powering them) but what I essentially need to do is turn the gain up. I'm not sure if the factory amp has a gain control on the outside, but I think it's very likely that it has one on the inside. Most amps (aftermarket too) have adjustment pots on the PCB. Has anyone ever seen inside one of these amps? I'd rather stay with the factory amp as it makes life simpler. It should definitely be powerful enough for the job.

If all else fails I may try to get a 4 channel amp small enough to fit in the factory location.

[Jeremy R.]

There are gain controls on the factory amp. If you take it out, you'll see three or four holes on the backside of it that let you stick a screwdriver in and turn the pots inside. Two are for gain, and the crossover is also slightly adjustable. Since they're not labeled outside, you'll probably want to take the bottom off to see which one's which. The circuit board is labeled, at least.

[anarchyx34]

YES YES YES!! THANK YOU! That makes this 10x easier (and cheaper).

[neomagus00]

i find it odd that you went with CDT speakers, a new head unit - but not a new amp. i glanced around the website, and the 6.5 components seem to like around 150 WRMS... i'm not sure that the factory amp can hit this (or even close), and even if it can, if it will sound good doing so. i think you would probably find a decent aftermarket amp (100x2 or more clean watts, or 75x4) would really open up the sound. just my opinion.

[lms]

I think the stock amp is 40 watts??

[Jeremy R.]

It's 35 watts per channel RMS, which is actually just fine for driving a pair of 6.5" woofers. Wattage ratings on speakers mean nothing, and the stock amp can easily bottom out some woofers on heavy bass tracks. I tested out quite a few before settling on the ones I have. Besides, there are maybe one or two aftermarket amps that can fit in that small space.

[neomagus00]

Originally Posted by Jeremy R.

It's 35 watts per channel RMS, which is actually just fine for driving a pair of 6.5" woofers.

i disagree - i run 75WRMS to mine, and they could easily do well with more. doubling the power to 150W per speaker only adds 3dB to peak output, but when running below that, the extra headroom can make a considerable difference in 'punch' and how 'easy' it sounds.

Wattage ratings on speakers mean nothing

perhaps true for lower-end equipment, but they are absolutely useful (and necessary!) for better stuff. CDT is pretty good - i would trust their ratings. power above their ratings can blow the speakers, and more power usually sounds better, so you generally want an amp rated at or near the Pe of the speakers.

the stock amp can easily bottom out some woofers on heavy bass tracks. I tested out quite a few before settling on the ones I have.

i'm more than willing to believe that, but bottoming out a woofer is easy with a 20 Hz tone and a clipped signal. running a 20 Hz tone cleanly and with appreciable volume requires a LOT of power. case in point - i can only hit about 110 dB at 20 Hz in my car (small sealed box, 1500 WRMS). granted, i'm hitting xlim maybe 6 dB before that, because of the box, but still...

Besides, there are maybe one or two aftermarket amps that can fit in that small space.

very true, unfortunately. while the original post said 'in the factory location', that may be a relaxed requirement if the situation warrants it, so i thought i'd mention the possibilities.