my subwoofer woes... help :( (1 Viewer)

[Anthony Sa]

So many problems, so little time.

My subwoofer is finally finshed, box looks good... but i still have to add the finish. tempest looks like a beast sitting in the box, looks like it wants to tear my house apart and god I want it to.

My amp, the QSC RMX 2450 is giving me but one problem. The power line... if it touches anything (and sometimes it doesnt) gives a hum into all of my speakers. I am thinking of installing a direct 20 amp line to where I plug in my amp so that I can have a dedicated power line and have no other cords touching the amps power cord. Could this get rid of the speaker humming?

My problem is this. Whenever i hook my amp upto the sub out on any reciever (only tried two recievers thus far, mine and my friend's) it does not work. It does not work out of any audio out of any jack. It will either give me nothing but distortion or give me a full signal. it gives me a signal with all the frequencies (out of the sub out) instead of just the bass frequencies. So I don't know what to do. Is there something wrong with my internal x-over on the reciever or what? I am going to get a Outlaw 950 within a few months so I dont' want to pay to have the reciever fixes (its a 5 year old onkyo.. cant remember the model). Is there a cheap way to fix this, for the time being? The Amp has a high pass x-over but not a low pass.

Thanks everyone

Anthony

 

[Patrick Sun]

It would really help if you identified the receiver's model, if it's old and doesn't offer proper bass management and output the "normal" subwoofer audio signal through the subwoofer output, you will need something to extract it from a high-level (speaker-level) signal and it it divvy the low's from the rest, or just upgrade your receiver to one that does the proper bass management.

Dedicated subs rely on gettng a true low frequency audio information passed through an amp which feeds the subwoofer. If your receiver fails in this area, you are on an island.

Some amps will allow you to siphon off the lows from high-level speaker input (and provide the passthrough to feed the other speakers, usually in a satellite/sub setup). But you need an amp with a robust crossover built into it to handle the high level signal and do the splitting of the signal like in a normal crossover within regular speakers.

 

[Tim Hood]

Gives you all signals...like pink noise?

Or gives you the full range, as if it were another pre-out?

If you're only going to have it for a little time, a really cheap, and a really dirty way of fixing it would just be to stick a choke on the speaker wire...

It's aweful, but it might hold you over???

Tim

 

[Pete Mazz]

It would also help if you detailed exactly how you have the amp configured. Stereo, mono-bridged, dip switch settings, etc. Also include how you wired the Tempest, and how its connected to the amp.

Pete

 

[Anthony Sa]

I will check on the reciever model... I will edit this post in a few minutes with the model number at the bottom.

It gives me a full signal, not the pink noise, but a regular pre-out signal.

The thing that is killing me, I have a new cable for the amp. I have a RCA -> 1/8 converter then the 1/8 cable goes to a dual XLR male. Last night (before I wrote the post) I listened to the sub because with my old cable there was a fair bit of distortion coming from the sub. Well after I hooked up the new cable, it seemed to go away. I listened to it this morning (just running a bass test, with the volume at less than half) and the distortion was still there! does anyone know why this is? I thought XLR cables were designed to have less signal loss and less distortion added!

The reciever model is: Onkyo A-SV640

 

[Patrick Sun]

Is this a Dolby Pro-Logic receiver, and not 5.1 Dolby Digital receiver?

 

[Anthony Sa]

It is a Dolby Ready reciever.... as I said before, a very big piece of junk, which will be replaced during the summer. It has 5.1 channel analog inputs but no digital inputs.

 

[Patrick Sun]

Then you'll need an amp that accepts speaker-level inputs to get that low end to the subwoofer.

 

[Tim Hood]

If he's only going to have it for a little while longer, then what is the issue with sticking a choke on the speaker wire?

Besides its a power sink hole, and not a real way to cross over a sub?

It will work...??? No?

Tim

 

[Anthony Sa]

Well I just tried my friend's reciever. It is an older sony with dolby digital and it did the same thing. I hooked it upto my DVD player via optical cable and tried to do a 5.1 channel setup. The subwoofer amp got only a distortion signal. In other words, only HISSING. this is pretty much what happens through my reciever, except a very faint full range signal. The thing i dont get... If i hook the cable upto my CD player, I have no distortion at all, and plays whatever the cd player is playing perfectly. If i hook the cd player back up and run it through my reciever, nothing but distortion.

anyone have clue on that?

BTW: thanks for all your help thus far

 

[Tim Hood]

This is a stretch, but do you have to turn the subwoofer output on, on your DVD player? Or is there some type of subwoofer dB level adjustment on it?

Tim

 

[Anthony Sa]

Yes, I have all of the subwoofer outs on and the DB settings to zero. I just ran and check that... that would have been a big kick in the pants if one of those settings were off!