i need some help....I just installed my system, and it was my first install....setup is MTX 801d mono amp pushing a single Kicker L7 10" 600 watt RMS sub in a 1 ft^3 sealed box, and a Pioneer 8600MP HU with 4volt preout.....my problem is, when i try to set the gain, there is not sound at all coming from my sub until it reaches 95% to Max....i don't think this is right....also, the sub sounds "muddy" and i would like it to sound as tight as i can....please help with suggestions on what i should do....thanks
You never want to set the gain near max. It'll blow the amp. Check all your rca cables, speaker wires, power wires etc. Also measure the voltage on the power wires. See if you get 12v with engine off, and around 14v with it on. Set the gain around 4v, disconnect the rca from HU, now touch one of them with your finger. If you hear a hum, then your amp is good. Test both channels. If however, you hear nothing, then your amp could be bad. As for your sub, wait till your amp/HU/installation is working.
i plan to check the wiring to make sure they are in phase....my sub is a Dual 4ohm sub, so i will make sure the wires run in parallel.....hopefully this will solve the problem....
ok...amp is getting 12v and 14v when the engine is running.....tried different rca cors and differnt preout.....also, made sure speaker wiring is correct.....and it all seems ok....i pulled the rcas from the HU and when i touched my finger to them i heard nothing....no hum....any suggestions? an MTX guy (the amp is an MTX 801d) told me that the amp has 8volt RMS input, and that with my 4volt preouts (pioneer 8600mp), it might take to about the max on gain to get volume....i don't think this sounds right....if i am not mistaken, if i have 4volt preouts, i should ge volume at about 1/2 way on the gain with an 8volt input....is this right? what else do you think could be wrong? thanks for thew help...
The gain on your amp is to match the voltage on your preouts (since it can be different for every HU) to the amp, so the amp doesn't make itself clip by over amplifying the signal. You SHOULD be able to get something to come out no matter WHERE the gain control is set. It's a variable control so that you can set it to whatever your preouts are. If you set the gain to high, you are going clip earlier, when the gain is set too low, the amount of noise in your sound is going to increase.
Setting your gain/level half way is a good starting point since it's 8v max on the amp. Do you have a walkman/portable cd player? Connect that to your amp's input and test it. If it still sounds very low, then you have a bad amp. Normally touching one of the rca wires should produce a hum in your amp. Since you said it didn't it sounds fishy.
MTX states that the amp has a min input of 200mV for proper functionality, and also accepts up to 8volt input....that means i should get output from the 4volt preout pretty much right away, correct? is there a way to test the preouts and make sure thats not the prob?
If you have another amp, you could sub it for MTX. Do the test I mentioned above. Find a walkman/iPod and use the headphone jack. Most of them will have around 250mw output, so if you connect that to your amp and use the volume control, you should be able to test. If it can't handle that then you have a bad amp.
Just get a set of RCA cables and an adapter to go from two female RCA cables to an 1/8" male jack. Connect the jack to your CD player and the RCAs to your amp. You'll probably just want to set the gain all the way down for that, although I don't think it'll matter all that much.
BTW, the preouts on your HU give out a consistent 4v, that will never change. The gain is just to adjust the amp so that it knows that your HU puts out 4v. If your amp goes up to an 8v gain, you should be ok at half way, or slightly below. Assuming your amp actually works anyway.
right....i was hoping there might be a way to test the preouts from the HU to make sure they are actually outputting 4volts and that they aren't the broken piece....is there a way to do that?
If you have access to a multimeter, you can use that to check your voltage. What you can do is unplug the RCAs from the amp, touch the positive to the center of one RCA and the negative to the outside sleeve part and you should get a reading of right around 4v. If that doesn't work, your RCA cables might be shot, so you'll have to pull the HU out and get it straight from the back of the HU. Put the positive into the center hole, and touch the negative to the outside part of the RCA jack. As far as I know, that should work. I may be backwards with the outside, inside, however. Also, make sure you have the multimeter setup correctly because if you set it up wrong and start touching to stuff, you could blow your multimeter. Although, in this situation with very low voltage, I don't think anything can go wrong, but fair warning either way. (I think that has to do more with plugging into a wall socket.)