96TL

I have my gains on my RF 1100A2 turned up pretty high (about 3/4 up) and it sounds good to me. Can I damage anything? I have RF 12" Power DVC subs BTW. The subs have soooo much more bass that way. I really should get another amp though.

jbrown

GAINS ARE NOT VOLUME CONTROLS!

The easy-cheesy way to set subwoofer amp gains, unless you have an oscilloscope ($1,500-3,500.00), is to turn the radio up to full volume while playing a bass disc (pink noise is better) and back it up a few notches (if max volume level is 35, set it to 31 or 32) then, starting from the minimum setting (and with all other amps or speakers off or disconnected) turn up the amp gains until you get audible distortion or your head implodes, whichever comes first.

The real way (again, only if you don't have an oscilloscope) is to match the amp's gain setting (volts) to the head unit's rated output voltage. These can sometimes be difficult to determine in the first place, much less set correctly due to poor amp labeling.

The best way is to use an oscilloscope on the outputs of the head unit to view sine waves or pink noise and turn the head unit up until you see waveform distortion and measure the voltage to make sure it is within the amp's limits in the first place. Then, with the radio set at that maximum distortion-free level, increase the gains until you see waveform distortion or your head implodes, whichever comes first.

Either way, your settings may already be correct, but it never hurts to check.

The reason it is important to correctly set the gains is to minimize noise and distortion, this leads to longer speaker and amplifier life and higher peak volumes. For the most part, power doesn't blow speakers, distortion blows speakers. When an amp is overdriven and begins clipping, it can inject large amounts of DC voltage into the speaker's voice coils, causing them to heat up, at which point, one or more of three things can happen:
1. the glue holding the speaker together will soften and the voice coil will separate from the cone.
2. the voice coil and/or former will melt and rub against the pole piece, shorting out the amp and likely causing damage to it, then the speaker stops moving, the former cools, sticks to the pole piece, and the cone freezes in place.
3. The amp self-destructs or (hopefully) blows a fuse before damaging a well-engineered speaker designed with poor-quality amplification in mind.
What causes an amp to clip? Improper gain adjustment (too high), improper impedance load, or overdriving the head unit (turning up the volume too high) and sending a distorted signal into the amp (amplifying distortion sucks).

96TL

Its hard to hear subs distort (for me at least). I'm gonna try what you said tomorrow. The radio has a 6.5 volt signal BTW. Its the Pioneer DEH-P920R. Anyway, should I keep the subwoofer level from the radio on zero when I do this?

jbrown

BTW, a 32 line sig??? Are you serious??? J/K

jbrown

If you are the only one driving your car and don't have to worry about someone jacking around with your levels, set it at zero. It is also a good idea to turn off the loudness - forever (a.k.a. the distortion switch) and turn the bass down to zero. Then, use the sub level and bass or E.Q. controls with discretion so you don't blow anything up.
BTW, are your subs in a sealed, ported, or bandpass enclosure? It could make a difference on how easy it is to hear the distortion.

96TL

You actually sat there and counted the lines??? Are you serious? J/K

I'm gonna maker it shorter, it is a little annoying.

96TL

Yes I am the only one driving my car thank God. I always keep the loudness off anyway. Right now I have the gains turned up and the sub level either at 0, +1 or +2. Also, I have the subs in a sealed enclosure. I'm gonna listen to it again tonight and try to adjust it. Thanks.

96TL

I realized that the subs sound the best when the gains are very low or very high, they dont sound as good in between. I hate this. I don't want to damage the subs or the amp. I'm gonna play with it more over the weekend. My neighbors complain at night.

Austin519

I'd only go as high as 90% on gain on any amp...above that isn't good for it.

Austin519

96TL

90%? Isnt that too high? I have mine almost all the way up so its probably about 90% and it sounded better lower. Way lower.

Austin519

It really depends on the amp...but as I said...90% max...usually the lower the better...

Austin519

96TL

I re-adjusted mine today and I set them about 1/4 of the way up. It sounds so much better. I'm gonna leave it that way until I get new subs.

jbrown

If you ever need to set the gains to 90%, you shoul probably start to consider purchasing a new head unit to avoid potential noise problems such as the dreaded audible tachometer, turn off pop, or plain old background hiss.

Austin519

jbrown:
Actually that's true jbrown...I was really talking in more terms of the amp by itself...what's not good for the amp...but yeah, you're right, that high will lead to the things you described...good point

Austin519