Amp compatibility

[89-300ce]

Hello,

I'm considering splitting my homebrew m1201 crossovers into HF and LF sections and driving my BMS4552NDs with a SET amp of 2-8w or a class A SS amp. I would be driving the LF with a 200wpc AB amp.

Am I likely to run into compatibility issues like phasing, etc?

Jorg

[Zilch]

N1201-8A?

Did you retain L1 and R1 in the lowpass and their connection to C1 in the highpass in your homebrews?

If so, how do you propose to deal with that?

[89-300ce]

I've tried to follow everything you've done with the M19 filter accross the forums and I thought you generated this at some time. It's what I was going to try.

Jorg

[ARG]

If your bi-amping , why would you want to keep the passives x-overs ?
You'll need to buy a good ( IE DBX) active crossover , any one with phase correction for either high or low output would be desirable .
The other thing is that even if you've good all the polarities correct on the inputs and outputs of the amps , they might not be in phase with each other . THis is always hard to check properly without an oscilloscope.
Next is that passive x-overs of more than 6dB/octave actually produce more phase distoration and coloration than almost anything else.
Class A SET ==== NICE
:blah:
Well thats my 2 cents.
Cheers..Ric

[Zilch]

I've tried to follow everything you've done with the M19 filter accross the forums and I thought you generated this at some time. It's what I was going to try.Skywave-rider has built it for his 9844s, and is giving it a shakedown.

I have the parts, but haven't put it together to test and measure yet.

Build it, try it, and let us know how well it works. My objective was to make M19 splittable, just as you propose.... :yes:


If your bi-amping , why would you want to keep the passives x-overs?To retain the adjustable passive compression driver compensation for extended high-frequency response.

To many, digital is not yet the panacea it is alleged to be....


The other thing is that even if you've good all the polarities correct on the inputs and outputs of the amps , they might not be in phase with each other.And using an active crossover with a phase inversion button relieves us of this burden?


THis is always hard to check properly without an oscilloscope.RTA checks it easily, and more....

[ARG]

Not all active powered "electronic" crossovers are digital , in fact very few are.
I find you tend to get much more control this way than with passive components. Just look at any professional sound system used to touring bands and everything they do uses active "electronic" crossovers .
That being said its always a good idea to have some kind of protection in place for the driver if you listening at higher levels . But home audio I don't see this as a problem.
I wasn't thinking that everyone had an RTA either ,that why I recomended a scope . Although an RTA will usually only indicate if the crossover frequency is adding or subtracting , it doesn't really indicate true phase.
And strangely enough some speaker networks sound better with the tweeter out of phase .
Richard Heyser of AES fame has written some pretty specific articles on absolute phase of speakers, and what he calls a minimum phase network.
On the last note , as I do pro-audio work one of things I've found out over the years in live sound and from many live sound engineers is that sometimes the best way to clean up the sound in a PA using cheaper passive crossovers is to to pull the crossover frequency down by 12dB or more .
Youd be amazed as to the results I've seen just in that one little problem area tweak.
Cheers..Rich :blah:

[Zilch]

Not all active powered "electronic" crossovers are digital , in fact very few are. I find you tend to get much more control this way than with passive components.Including the subject adjustable compression driver compensation? :yes:


I wasn't thinking that everyone had an RTA either ,that why I recomended a scope . Although an RTA will usually only indicate if the crossover frequency is adding or subtracting , it doesn't really indicate true phase.Like the ubiquitous oscilloscope does? :thmbsup:


And strangely enough some speaker networks sound better with the tweeter out of phase.No kidding? How could that BE? :dont-know


On the last note, as I do pro-audio work one of things I've found out over the years in live sound and from many live sound engineers is that sometimes the best way to clean up the sound in a PA using cheaper passive crossovers is to to pull the crossover frequency down by 12dB or more.Would that technique be applicable to the more expensive ones, as well? :blink: