simple crossover for a subwoofer

[bmxfelon420]

I have a subwoofer that i ripped the lpf out of, on account of it sucking. Is there a simple way i can make a low pass filter?

[efzauner]

Um why was it sucking? Most subs blow! (sorry could not resist)

but before answering the questions, you need to provide more info. What make and model subwoofer is it?

or at least answer this:

Is it a passive subwoofer with a passive crossove that simply connects to an amplifier's speaker outputs or is it an active subwoofer that connects to a HT receiver's subwoofer output jack? Do you have to plug it into the wall?

[bmxfelon420]

it was a passive sub but i rewired it to be hooked directly to an amp. In this case a 160w coustic car amp. The amp unfortunately has no crossover, but the one for my 3 ways does, but the coustic isnt powerful enough for those so it has to be used on the sub. I hooked it up but it sounds li8ke complete, insane *** without a crossover.

As for the brand, its cheapness cheap that is probably only worth the box its built in. 200w rms rated. since they are 6.5" i plan on getting some broken promedia subs and putting the drivers in just to see how it turns out(later), but for now i just want to see if i can cobble these together. I have enough old crap laying around that i can probably salvage some parts to make it.

[efzauner]

So it was a passive sub with a built in passive crossover (basically just a coil, maybe a cap), connected directly to a power amp. OK, so you removed the existing crossover and now you want something better.

Since you are already using a car amp, why not go for an inexpensive electronic crossover from Pyramid or the like? you can find em on ebay cheap. Hook it up just like you would in a car: From your home audio receiver pre amp out or tape monitor out to the xover. The low pass output of the cross ove to the sub amp to the sub, and High Pass output back into the power amp in or tape monitor input of your receiver.

Is this being used just to add some low end to your stereo? Or for a HT receiver. Please describe more of what you have. Do you have a regular pair of speakers? A stereo receiver or amp?

[bmxfelon420]

i have one amp hooked to my 3 way stereo speakers, and then the other amp that i was going to use for the the sub. That amp is hooked up with just the line out from the first amp, and the whole mess is run off of the tv's speaker out.

[efzauner]

Ok, I see what you are doing. I've done this sort of thing...perhaps in my youth!

On your TV is the connection intended to connect another set of loudspeakers or headphones? Can you use the TV volume control to adjust the volume of the sound going to the first amp(the one connected to your 3 ways?) . Generally the quality of the sound comming from the speaker out is not that great. Does your TV have a pair (left and right) Audio out RCA jacks? (most can also be controlled by the volume control) Are you using a VCR? Most VCRs have stereo Audio RCA outputs. (but no volume control)

I am trying to figure out why you say your bass was bad and you had to rip out the cross over. That is usually not the culprit. Passive crossovers are not rocket science and I doubt that it was the source of the problem. There may not be alot of bass comming out of the TV speaker output anyway. It may also be modified by any TV sound processing such as BBE.

I really have no other suggestions that to use an electronic crossover designed for cars. Either a very simple one that just does low pass to the sub amp. Something like this

http://cgi.ebay.ca/NEW-ELECTRONIC-LOW-PASS-CROSSOVER-FOR-CAR-STEREO-SUBS_W0QQitemZ9709177126QQcategoryZ79840QQrdZ1QQcmdZViewItem

Or, if your 3 way speakers cannot reproduce much bass, then you need something with a high pass for them as well. Something like this:

http://cgi.ebay.ca/LEGACY-LXR7A-ELECTRONIC-CROSSOVER-NETWORK-SYSTEM_W0QQitemZ9709239013QQcategoryZ79840QQrdZ1QQcmdZViewItem

BTW how are you powering the car amp at home? If you are using a 12 volt battery charger, it may not be very clean power. It has probably some bad 60/120 Hertz ripple.

You can fool around alot with fixing your present sub, or simply watch ebay, be patient. You can get something interesting for under $100 and get something real. something like this

http://cgi.ebay.ca/BRAND-NEW-YAMAHA-YSTSW215-POWER-SUB-WOOFER-YST-SW215_W0QQitemZ9708725715QQcategoryZ3275QQrdZ1QQcmdZViewItem

[bmxfelon420]

The 3 ways produce a lot of bass since i hooked them to a new amp. Im powering the amps with 2 old AT computer power supplies. I cut most of the plugs off and twisted the grounds and 12v ins together to hook to the 740w amp for the 3 ways (only 2 channels used right now) and for the sub's amp, its just soldered straight to the bundles because that amp doesnt have terminals. The noise isnt too bad, its a little loud for my liking but not as bad as some i have heard from stereos before and certainly not an issue once the music starts. Ill probably check on a crossover for a car, since that will work good. Ill probably get a 12v power brick to run that though since crossovers probably dont take tons of power.

The TV has rca outs, which i have hooked to the amps. I have the bass and treble settings neutral on my tv, and the 3 ways are using their own internal crossovers, with the ones in the amp disabled. I have a little bump in the bass gain, because i think the tv is kinda weak in that department if i left it alone.

If it were cost effective, i would get a deep cycle marine battery and a charger to run them, the power would be much cleaner. This is how the car audio place here powers their displays. But id rather get a new 5.1 reciever than do that, but i will need the subwoofer amp working for that anyways

[efzauner]

Honestly there is only so far you can go with this. Do not waste any more money by buying a marine battery (and the charger needed). Those 2 will cost $200-300 anyway. You dont want a lead ACID battery in the house anyway. I really suggest that you invest in a HT receiver and a sub. Sell the amps on ebay and buy the real thing.

something like this

http://cgi.ebay.ca/Onkyo-TX-SR502-6-1-channel-Receiver-Brand-New-in-Box_W0QQitemZ9711839439QQcategoryZ39797QQrdZ1QQcmdZViewItem

or

http://cgi.ebay.ca/Pioneer-VSX-516-K-S-100w-x-7-Receiver-In-Sealed-Box_W0QQitemZ9711966799QQcategoryZ39799QQrdZ1QQcmdZViewItem

What ever it is, make sure it has Dolby Digital (not just pro-logic since that wont let you decode DVD surround) and make sure you get the remote because a new one will cost about $100.

Have fun.