What is all this unwanted noise?

floyde20032001

I have 2 Boss 800 watt/ 400 rms subwoofers in a sealed box in my trunk. I also have a 2 channel 800 watt amplifier. When i turn it up most of the way, i get this annoying buzz that comes out of the subs and it sounds horrible. I was wondering what could be causing this sound when i have the high pass sounds filtered out and i was also wondering if it might be my custom casset player (which is a 97) or if it was my lanzar amplifier?

LittleCar_w/12s

... but everything you said could be a problem. :eek:

Seriously, though, you should help us help you by telling us what wiring you have, who installed it, what kind of car, and any troubleshooting you have done so far. Does it only happen with the volume up? or all the time, just less? Increase with motor or not? etc....

neomagus00

since you said it was an 800 watt amplifier and only 400 watt subs (only the rms matters, peak isn't worth a damn), please stop turning it up immediately - you will cook your subs. now, go here and follow those directions. that should eliminate the buzz you're hearing... now, i'm assuming the buzz is because you're pushing the drivers into overexcursion. if this is not the case, what jerry said is right, it could be any of it. you mentioned that it was only when you turned it up high. this really leaves only power issues, not signal issues (which are the ones that concern the cassette and highpass issues). in order to help you further, please list everything that jerry said - wiring layout (specifically how you're wiring the 2 channels to the subs, including impedances of the subs), what you've tried to fix it, what subs they are, if the 800 watt amplifier is 800 watts rms or peak, at what volume does the buzz begin (and how high the HU goes), what is the gain on your amp set at, what is your headunit, and how well built the box is - this could very well be an air leak coming out through a small unsealed seam in the box.

a good confirmation that it's overexcursion is to do the following, but you must have a headunit that increments its volume (most do, this just means that it goes 1-2-3...-20-...), as opposed to a smooth slide: get a friend to help for a few minutes, and get a cd with a test tone on it (if you need, i can post a suitable one for you to burn onto CD). then have this friend (we'll call him/her Pat) turn the volume up until you, looking at the subs, can see the logo or whatever get a little blurry, where you can just begin to see the sub move. now have pat turn the volume up slowly, one click at a time, and note how far the blur moves at each click. at the beginning, it should increase about the same amount for each click - that is, if it was about 1 centimeter at 15, and it increased to 2 cm at 16, it should go to about 3 cm at 17... note when the buzz begins. if the distance isn't increasing linearly like this, if it's only increasing a little bit (less than it was at the beginning) for each volume click, then you're at the limits of your driver. note that if you choose to do this you should do so before you do the gains adjustment i linked to above, because that will walk you through setting your amp such that this overexcursion doesn't happen.

floyde20032001

The amp is 800 watts peak. The speakers however are 800 watt speakers and the rms for them is 400 a peice, which is the most amount of power they ever get. As far putting them together, i did that and then had Ideal Audio put the wiring from my cassete deck to the amp in. The subs are hooked into the amp with 12 gauge speaker wire so i'm pretty sure it's not that. I've listened to the box and there are no leaks and it is a sound that is actually being made by the speaker when i turn the sound up most the way only. Lastly, the car i've got it in is a 97 dodge intrepid.

neomagus00

okay, if you follow that link i posted, it should fix the problem. if it doesn't (or in any case) you should be quite sure that the speakers are sealed to the box very well - air leaking out around the edges can sound like speaker noise, and it's worth sealing in any case - just use 1/2" weather stripping (in the windows aisle of a local home depot/lowes or something) and lay down the foam under the sub, then screw it in good and tight over that.

btw, a sub with 800 watts peak is not an 800 watt sub; both amps and speakers are referred to using their rms or continuous values; peak values are nearly entirely worthless and should very rarely be mentioned...

Joelsbass

yeah... peak is pretty much what you get if the amp is struck by lightning :eek: