new amp potential problem?? please help

[dave9382]

so i got a brand new 75W X 4 amp for christmas and finished installing it the other dayits the audiobahn a6004T http://www.onlinecarstereo.com...13489the problem is although it is working fine it does not sound all that much louder than my panasonic head unit did when it was pushing the speakers.I have the levels all the way up on the amp.. and i double checked all the wiring... it sounds very good and all its just not all that much louderid say id have to have turned my panasonic head unit up to 25 outta 40 volume when it was pushing its 14W RMSX4 to get about the same volume I am getting turning the volume up to 20 outta 40 with the amp pushing 75W X 4 RMS.is this normal? I expected a bit more ummphh from adding an amp...this is my second amp is it possible its not getting enough power or something ? (the power light lights up fine) and adding a capacitor might help?i havent had an amp pushing my speakers before and wondering if this was normal and all i could be expecting in terms of power improvement up from 14RMS to 75RMS X 4....Anyone have any opinions? Thanks,David

[dave9382]

oh also i didnt notice my lights dimming or anything with the volume turned up... the sub amp is 500W RMS rockford fosgate, this amp is 75WX4...it just doesnt appear to be a power problem but i was really expecting more from an amp in terms of volume and umph

[rocket9005]

You increased your power about 6db which isn't a that much difference, You have to go 10 db, which is 10 times the power, to get a 2x difference in percieved loudness. I don't knpw what you listen too, and where you hooked up your amp, but you should have a cleaner midrange. It's the kind of stuff you hear when you are not moving (road and wind noise can mask the improvments)

[dave9382]

ya thats what i figured.. it certainly makes listening at lower volumes more pleasureable because it comes through a lot cleaner because i dont have to turn the dial up as loud... i am pleased with the improvement just didnt know if i could expect a lot louder.. I think the next project is dynamat so when i do turn it up to 30 on the dial my entire car isnt rattling thanks for your help

[idontknowwhatimdoing]

Turn them gains down holmes...you should set the gains so that at FULL volume on the deck you are just a tick or two under the level where audible distortion begins....this will allow the amp to make the headroom that will offer MUCH more clarity and volume. Try it....you may like it.

[dave9382]

ok ill try that

[dave9382]

what about setting the gains with my head unit at 35/40 would that work just say well? I want to be a little cautious I have 75RMS going to some 65WRMS full ranges in the back (the components in the front are 100W RMS so they should be fine)would that work just the same way?

[idontknowwhatimdoing]

If you have deck power going to any speakers, set the deck level that references the max that those speakers can handle before distortion, then back it off a tick so it is just under their distortion level and then reference the amp gains to that volume level. That is your new "MAX" volume setting.

[idontknowwhatimdoing]

OK, I just re-read the entire post again....(clobbers own self in melon and cleans up own stupid slobber, duh) Since you don't have deck power going to any speakers, just reference the gains as I originally stated. The extra 10 watts will not hurt the rear set, but rather run them better. The only way an amp makes it's rated power is at full power input (and full voltage if unregulated power supply) so you should be OK.

[dave9382]

so i tried this today. it seems that not matter how low my gains were on my amp i was getting some nasty noise and distortion when turning my head unit up past 35 of 40 no matter how low i seemed to set the gains on the amp. it also wasnt near as loud either... is there a reason for this or anything i can do to help it? it sounds a whole hell of a lot better having the gains all the way up on the amp and just having the deck playing between 15 and 20 out of 40

[idontknowwhatimdoing]

are you running the door speakers full arange or do you have a crossover on them?

[idontknowwhatimdoing]

Also, do you have any speakers wired to the deck directly? Do you use the pre-outs on the deck or is it wired through a line output converter?

[idontknowwhatimdoing]

After review of the amp, I recommend the following:1. Set the subsonic filter on and raise it to the max frequency (50hz?)2. Set all crossovers to HP and cut @ 100 - 150 hz3. Turn "bass boost" off4. if you are running "high level" inputs, change them to preamp level from the deck. I.E. Run RCA connectors from the deck to the amp.Then reset the gains and give it a try. If you are still getting distortion, you are at the deck's "max" before the thing distorts...and it does happen in some decks. Set the levels to the number where audible distortion is not present, that is your max volume level and set the gains below distortion as well.