To bi-amp or not to bi-amp???

I just beamed my ADS 910 with an active crossover on Sunday night and I have not stopped listening. Mc225 top/mid Mc2100 bottom. The improvement is fantastic.
 
I just beamed my ADS 910 with an active crossover on Sunday night and I have not stopped listening. Mc225 top/mid Mc2100 bottom. The improvement is fantastic.

Those who have not tried are missing out on something that can be wonderful. What's not to like about having the ability to dial your speakers in to your own particular taste? I've tried crossover settings from the 800Hz. that Altec chose for Valencias up to 1200Hz. I've left it at 1000Hz. after many hours of trials.
 
As long as the speakers have separate terminals for LF (+) (-), HF (+) (-), and the jumpers are removed there should be nothing common to cause problem for amp or speakers.

If there is a common ground, e.g. three terminals on the speaker ( common (-), LF (+), HF (+) ) then maybe there could be some weirdness if the amps weren't common ground.

Which has the effect of removing the woofer from the rest of the crossover.

Shelly_D
 
Which has the effect of removing the woofer from the rest of the crossover.

Shelly_D

Indeed. Just the way it was worded came across, to me anyway, like there was some sort of extra special modification necessary.
 
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Indeed. Just the way it was worded came across, to me anyway, like there was some sort of extra special modification necessary.

If the speaker did not have the separate LF and HF terminals, there would be. I assume that you already knew that.

Shelly_D
 
I assume that you already knew that.

Shelly_D

No. I've been bluffing for years. All I have is an AM mono clock radio.

More seriously though, yes, that's why I found the comment confusing since removing the jumpers would be common knowledge. I wouldn't expect someone would connect two amps to one set of terminals.
 
Got the MC60's in yesterday. They are absolutely beautiful. They were restored and upgraded by Vintage Vacuum Audio in 2015. Found a great deal on a Marchand XM9 crossover. Making a list to order up cables and parts for my speaker mod. I'm excited about this project!!
 
Check for chassis sag (top plate), it is very common on MC60 and MC30, especially MC60.

Lengthwise across the top of the chassis at the center point one has an 1/8" inch gap and the other 1/4" gap. I'm 60 years old and my chassis is sagging in places too.
 
Those who have not tried are missing out on something that can be wonderful. What's not to like about having the ability to dial your speakers in to your own particular taste? I've tried crossover settings from the 800Hz. that Altec chose for Valencias up to 1200Hz. I've left it at 1000Hz. after many hours of trials.
I am still tweaking. It's at 500 hz now. It really is a very nice improvement. I will probe;y invest in a better crossover at some point. The Ashly is a bit of a weak link, I think. I didn't want to spend too much at first but I am really enjoying the sound and I believe a better crossover would improve the sound even more.
 
What's wrong with the Ashly? I'm using one with my MC60s, MC250, Citation 1 and Bozak Symphonies. Sounds great to me...
 
You can do that, BUT you MUST remove the woofer off the crossover network and tie it to one of the amps directly. If you leave all the speakers on the crossover, then you end up tiring the outputs of the two amps together and that causes all sorts of failures, certainly in the amps and possibly in the speakers too.

The whole idea of biamping is to separate the highs and lows to delay the onset of clipping. Earlier in this thread I posted a link to Rod Elliot's excellent article on the subject. It explains the "what to do" and "why it works" much better then I do.

Shelly_D

So wait, if I remove the jumpers from my speakers (it has terminals for high, mid and low) and connect an amp to each set of connections yet keep the internal crossovers (something I have done and liked the results I got a lot) am I endangering the amps? I knew by going passive I wasn't really getting all the benefits, but my speakers seemed to really like the power. I can only imagine that with active crossovers I would notice an even bigger improvement (or not...who knows until I try I guess) but i never thought I was abusing the amps by doing this. The speakers have the jumpers to supposedly facilitate the bi-amping, or so i thought. Why else have them, and not also include some easy way to bypass the internal crossover network?
 
So wait, if I remove the jumpers from my speakers (it has terminals for high, mid and low) and connect an amp to each set of connections yet keep the internal crossovers (something I have done and liked the results I got a lot) am I endangering the amps? <<snip>>

No, not endangering the amps. You remove both jumpers from both speakers, the amplifiers' outputs are not tied together through the speakers' crossovers. This is the easiest way to bi-amp and what the dual-input with jumpers is designed for.

The only thing remaining is that you are still going through a crossover (high-pass filter) to the mid and one to the tweeter (if 3-way, otherwise just one to the tweeter/HF). This can still affect the sound and to some extent the power requirement for the upper frequency drivers. The woofer OTOH, it depends. Some speaker manufacturers run the woofer directly from the speaker inputs, others have some type of high-pass to filter frequencies below where the speaker can perform.
 
...and not also include some easy way to bypass the internal crossover network?

Because of the disasterous number of losses of tweeters and perhaps mids that would occur by people hooking up stuff they thought they knew about.
 
No, not endangering the amps. You remove both jumpers from both speakers, the amplifiers' outputs are not tied together through the speakers' crossovers. This is the easiest way to bi-amp and what the dual-input with jumpers is designed for.

The only thing remaining is that you are still going through a crossover (high-pass filter) to the mid and one to the tweeter (if 3-way, otherwise just one to the tweeter/HF). This can still affect the sound and to some extent the power requirement for the upper frequency drivers. The woofer OTOH, it depends. Some speaker manufacturers run the woofer directly from the speaker inputs, others have some type of high-pass to filter frequencies below where the speaker can perform.

^^^

His answer is clearer then mine would have been but I agree.

Shelly_D

Because of the disasterous number of losses of tweeters and perhaps mids that would occur by people hooking up stuff they thought they knew about.

Thank you! I was worried i had screwed up. The speakers in question are DefTech BP 2002 bi-polar speakers.

I noticed that they just loved power, so one week, when I had a second identical amp (Outlaw 750 5 channel amp..165 wpc) I decided to try removing the jumpers and giving the highs and mids 165 watts each. The woofer is a self powered sub that gets its signal from the preamp, and has separate inputs for music and movies "low" and "LFE" so at that point it was effectively tri-amped.

The improvement in sound was not subtle. The guy behind the BP2002 is the same guy now making Golden Ear speakers. Of all the HT specific speakers I auditioned (and I auditioned A LOT of speakers) these are IMO the best for double duty HT and 2-channel. Even better I thought than the bigger BP2000 which was monster tower array with 4 mids, two tweeters and a huge subwoofer. Although, the 2000 was the ultimate HT speaker, it wasn't as detailed for music, I thought.

I may just start looking for a used Outlaw 750 and make it a permanent situation. :)
 
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