Speaker Bi-Amping / Crossover

[igorcherfas]

Hi,

I have a set of custom speakers built out of the older Infinity SM-155 series. Basically there's 2 of the SM155 Tweeters, 2 Of the Mid-ranges and 1 Cerwin Woofer. I blew the crossover in one of them.

//Edit the crossover, is also just the stock. SM155 Crossover.

I would like to bi-amp them as my denon 688 is not really powerful enough to run them whole. Currently they are single post. i would need to change the backplate, I have 2 bi-amping plates from parts express.

I understand with bi-amping on the 688 I'll loose my ability to do 7.1 that's fine with me. What im confused about is, to my understanding with bi-amping i can go active, so i wouldnt need the crossover. Would this work with the 688 or would i still need a crossover and how would i wire all this up. I looked on parts-express for crossovers, but couldnt seem to find what i needed.


Some help would be greatly appreciated,

Thank's
Igor

 

[jleaman]

Hi,

I have a set of custom speakers built out of the older Infinity SM-155 series. Basically there's 2 of the SM155 Tweeters, 2 Of the Mid-ranges and 1 Cerwin Woofer. I blew the crossover in one of them.

//Edit the crossover, is also just the stock. SM155 Crossover.

I would like to bi-amp them as my denon 688 is not really powerful enough to run them whole. Currently they are single post. i would need to change the backplate, I have 2 bi-amping plates from parts express.

I understand with bi-amping on the 688 I'll loose my ability to do 7.1 that's fine with me. What im confused about is, to my understanding with bi-amping i can go active, so i wouldnt need the crossover. Would this work with the 688 or would i still need a crossover and how would i wire all this up. I looked on parts-express for crossovers, but couldnt seem to find what i needed.


Some help would be greatly appreciated,

Thank's
Igor

You would not be able to go active with this, as you have a surround sound receiver, if you wanted to go active you need a 2 channel amp for each crossover-bi amp.

IE, 2 channels for the mids tweeters, and 2 channels for the bass drivers.

 

[Key]

If he has individual volume controls on the front and back channels it could work. You'd either have to come up with an active buffer before the amps to replace the crossover or use DSP filters and feed it from a computer though.

 

[jleaman]

If he has individual volume controls on the front and back channels it could work. You'd either have to come up with an active buffer before the amps to replace the crossover or use DSP filters and feed it from a computer though.

The denon 688 doesn't do this, its either hdmi input optical/coax or R/L inputs.

If you really wanted to do this, you could buy / build a 4 channel amplifier and run the pre-out on the amp and do it that way.

NVM, it doesnt have pre-outs.

An externally hosted image should be here but it was not working when we last tested it.

 

[Key]

Looks like it has discrete inputs to me. Under "Ext In"

 

[jleaman]

Looks like it has discrete inputs to me. Under "Ext In"

Don't think it will work that way, plus that's only one source, i bet he is running more than one source.

 

[Key]

It's the place where you would need to feed the filtered audio. So the source number would be limited by the active buffer or soundcard. It would be limiting no doubt. But technically it will work the way I described. I am using a crappy 1970s Sansui quad receiver with discrete inputs and if that thing will do it his will probably work better haha. But if he wants them up and working the way they were before then yeah the easiest way would probably be to repair the passive xover.

 

[jleaman]

But if he wants them up and working the way they were before then yeah the easiest way would probably be to repair the passive xover.

That would be the simple and proper way to do this, and if there is not enough volume, he needs more efficient speakers for sure.!

Plus 7.1 in is not really 7.1 out, its 7.1 in then through a processor etc etc, then out. more work than what it's really worth.

J'

 

[Key]

Yeah if it always has a decoder on then I wouldn't bother. But if it's got a discrete output aka "DVD-A Ready" or what in the seventies and sixties would be used to playback a quad reel or a CD4 decoder then it is a perfectly acceptable kludge to experiment with imo.

 

[jleaman]

Yeah if it always has a decoder on then I wouldn't bother. But if it's got a discrete output aka "DVD-A Ready" or what in the seventies and sixties would be used to playback a quad reel or a CD4 decoder then it is a perfectly acceptable kludge to experiment with imo.

yup,


IMO tho, Fix speaker - replace with better speakers ( would be cheaper too)

 

[igorcherfas]

I really only run one source optical from my computer, I understand now that im not going active.

Thanks for clearing my confusion up. How can i bi amp these with a crossover, i understand i would need two, a low pass and high pass for mids/highs and woofer. I Found the specs to rebuild these 155 crossovers, but i figure i wouldn't be able to bi-amp with that crossover anyways, as it only has 1 input?

What crossover's could i buy to bi amp this and get rid of the stock crossover? Looking on parts express just gets me lost.
Sorry i am definitely very new to this.

Thank's
Igor