Crossover’s for Bi-amping

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Davey

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Re: Crossover’s for Bi-amping
« Reply #20 on: 8 Mar 2013, 06:52 am »
The XM-9 is not a discrete component crossover.  It utilizes op-amps in a state-variable configuration just like the XM-1.  It does have the advantage of separate buffer amps to pick-off the low/high pass signal from the state-variable topology and also incorporates levels controls and a "damping" function which changes the Q of the filter sections.

Both the XM-1 and XM-9 are rather dated designs.  The newer XM-44 unit utilizes a Sallen-Key topology and is quite a bit more versatile.

If you're really looking for a discrete component crossover pickings are very slim for commercial units.  DIY is the way to go.
DIY is really the way to go for op-amp-based crossovers too.  :)

Cheers,

Dave.

WireNut

Re: Crossover’s for Bi-amping
« Reply #21 on: 8 Mar 2013, 04:53 pm »
I was looking at the Marchand XM-44, it does look like a nice unit and seems to be the most flexible of all his xover's. I bought the Rane AC22S to try out due to it cheaper cost and since I now have balance equipment, and it's also easy to experiment with different frequency's. Maybe going balanced really won't make a difference in the end, my cables are only going to be 3 feet long. I'm hoping my amps may benefit from operating in balanced mode. The wires are suppose to be delivered today so I can start making the balanced interconnects.

Davey

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Re: Crossover’s for Bi-amping
« Reply #22 on: 8 Mar 2013, 06:10 pm »
Other than possible reduced hum/noise pickup issues, there isn't any audible benefit to running balanced cables.  Your equipment (in almost all cases) is not running in "balanced mode," you're just utilizing a balanced 'interface'.  The vast majority of equipment has unbalanced circuitry within.  The Rane AC22, Behringer's, ART310, etc, etc.....

However, if you're interested in twiddling, the only way to go is a DSP unit.  :)

Cheers,

Dave.

WireNut

Re: Crossover’s for Bi-amping
« Reply #23 on: 8 Mar 2013, 06:13 pm »
Other than possible reduced hum/noise pickup issues, there isn't any audible benefit to running balanced cables.  Your equipment (in almost all cases) is not running in "balanced mode," you're just utilizing a balanced 'interface'.  The vast majority of equipment has unbalanced circuitry within.  The Rane AC22, Behringer's, ART310, etc, etc.....

However, if you're interested in twiddling, the only way to go is a DSP unit.  :)

Cheers,

Dave.

What is a DSP unit. Tell me more. Who makes them ?
Oh, like miniDSP. I haven't figured them out yet. I was reading about them but there software based so I was thinking "PC" so I didn't continue reading about them. I really want to experiment. I've been using my current xover so long it's time to try something new.


Russtafarian

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Re: Crossover’s for Bi-amping
« Reply #24 on: 8 Mar 2013, 07:25 pm »
How are you using the crossover?  Is it just for subs below 100hz, or are you crossing over midrange and tweeter drivers as well?  The higher noise and lower transparency of less expensive analog or DSP units won't make a big difference if used only on subs.  If you are passing full frequency music through the XO, then you'll need to focus on higher quality (and more expensive) units.

If you're only using the crossover for subs, consider using it on the sub signal only.  From the preamp, split the output and connect one output to the sub xo and the other to the main speaker amp, bypassing the crossover.  Use a passive high pass filter at the input of the main speaker amp if you need to remove low bass from your main speakers.  Much more transparent this way.

Russ

WireNut

Re: Crossover’s for Bi-amping
« Reply #25 on: 8 Mar 2013, 07:51 pm »
How are you using the crossover?  Is it just for subs below 100hz, or are you crossing over midrange and tweeter drivers as well?  The higher noise and lower transparency of less expensive analog or DSP units won't make a big difference if used only on subs.  If you are passing full frequency music through the XO, then you'll need to focus on higher quality (and more expensive) units.

If you're only using the crossover for subs, consider using it on the sub signal only.  From the preamp, split the output and connect one output to the sub xo and the other to the main speaker amp, bypassing the crossover.  Use a passive high pass filter at the input of the main speaker amp if you need to remove low bass from your main speakers.  Much more transparent this way.

Russ

I can go either way, my preamp has dual balanced or Rca outputs. I'm only using the xover on the bass cabs really. After I do some experimenting with the Rane xover frequency's on the bass cabs I may do that. But it will defeat some of the options the xover will give me to the mains. In the end I'm looking for the best fidelity. This is going to be interesting. The wires are in, time to learn how to do a 3 wire braid and get busy making the interconnects.
 


edwyun

Re: Crossover’s for Bi-amping
« Reply #26 on: 8 Mar 2013, 08:08 pm »
The other question is whether you'll be using the passive XOs in the speakers or not.  Best would be to remove them from the audio chain.

While I would agree that digital is the way to go for time alignment and certain phase shaft issues and other manipulations that are difficult otherwise, I still prefer analog.  But yes, there aren't that many out there within a relatively reasonable price.

Even with RCAs, I don't have any ground or hum issue which I expected given the number of amps, transformers, and cabling.

WireNut

Re: Crossover’s for Bi-amping
« Reply #27 on: 8 Mar 2013, 08:22 pm »
The other question is whether you'll be using the passive XOs in the speakers or not.  Best would be to remove them from the audio chain.

While I would agree that digital is the way to go for time alignment and certain phase shaft issues and other manipulations that are difficult otherwise, I still prefer analog.  But yes, there aren't that many out there within a relatively reasonable price.

Even with RCAs, I don't have any ground or hum issue which I expected given the number of amps, transformers, and cabling.

Yes, I have a 4 box system. Top cabs use passive xovers which can't be defeated and go to 1 amp, Bass cabs go straight to the 2nd amp without using any passive xover.

WireNut

Re: Crossover’s for Bi-amping
« Reply #28 on: 9 Mar 2013, 01:00 am »
I use a First Watt B4.

I prefer using discrete electronics and no op-amps for XOs to minimize any sonic signature.  The dbx's and behringers are good and getting better but many make DIY improvements due to their sonic signature.

I emailed Pass Labs last night asking if the First Watt B4 was available with balanced XLR inputs and just now received an email from
Nelson Pass and I was like  :o  :o  :bowdown:.
I might have to frame that email.

edwyun

Re: Crossover’s for Bi-amping
« Reply #29 on: 9 Mar 2013, 02:16 am »
Papa (Nelson) is good about that.  He regularly posts on the diyaudio.com forum.

The First Watt B4 only came with RCAs.  The Pass Labs XVR1 comes with RCAs and XLRs.