[Hoosierdaddy]

Good Evening VS gang!

I am in the beginning phases of building another system and have a couple of rudimentary questions:

If I have a pair of Pass 600.5 monos-what kind issues would I have with a speaker like VS that have different impedances on the top vs. bottom?  If a speaker is 8 ohm on top and 4 ohm on the bottom would this equate to 600w on top and 1200w on the bass bin?  Or would it be 300w on top and 600w on the bottom?  Or something completely different?

Sorry for the dunce question.  When I have used two amps in the past, they were two different stereo amps with one used to power the top and the other the bottom...

Regards,
Hoosierdaddy

[es347]

You'd probably have to attenuate the signal being fed to the lower Z module.

[Hoosierdaddy]

Gavin,

What do you do with your MC501s?

Regards,
Hoosierdaddy

[fplanner2000]

FYI
I am running a pair of VAC Phi 300.1s to my VR-7SE's.  Each speaker is bi-wired to its own amp and I am getting excellent results.  This might help you.

[JackD201]

Hi Hoosier, you don't have to do a thing. Because of the passive crossovers, the amp sees an average 6ohm nominal load with a high of 8 and lows a shade under 4 ohms. Your amp might draw 1.2K at some transients. I think even at insane listening levels your 600.5s won't even break a sweat.

If bi-amping. It all balances out. The 4ohm load is 3dB less sensitive. As it draws double the output power the 3dB is put right back. With a pair of identical identical stereo amps you can either run horizontal or vertical bi-amp with exactly the same results.

My oh my. What a nice conundrum to have!!!!!

[es347]

Gavin,

What do you do with your MC501s?

Regards,
Hoosierdaddy

I'm not vertically biamped (I think that's what I mean)....one amp per channel.  I run biwires and as Jack said, Albert's crossovers take care of business.  I just turn 'em on and stand back.

[SoundsGood]

I run my VR-7Se with tube monoblocks on top and solid state monoblocks on the bottom.  I run pink noise through the top only and measure SPL with a meter, disconnect the top and run the bottom only and measure that output.  I use an attenuator from Scott Endler to balance the output from the top and the bottom.  Attenuator plugs into the amp input.  You can also balance left and right the same way.  On my system I have to attenuate the bass amps to even it out with the top tube amps.
Albert has some info posted on this subject.

[Ambiance]

When you bi amp with the same set of amps, you do not need to worrie about gain issues, and differens in power. And to do a bi-amping with two monos there is only one way to go, and that is horizontal. Why not just let one amp take care of one side each? The 600.5 are capable to handle VS speakers without any problems. 


A.

[Hoosierdaddy]

Thanks, gentlemen!  After reading responses I realized that I was over-thinking, analysis paralysis if you will.  Now, time for a little bargain hunting...

Regards,
Hoosierdaddy

[stewie]

One thing I like about letting one amp handle the tops and another handle the bottoms (I've got tubed monos on the tops of my VR4 gen3s, ss bottom) is that one can, by means of an attenuator, adjust the bottom-top mixture to taste. 

[es347]

I agree with stewie's logic.  Go with a super fast, high wattage amp on the bottom and try a couple of really decent tube amps on top, balanced designs if you can find them.  If you get the proper balance top to bottom, you should have the best of both worlds.  A pair of the old Krell monoblocks on the bottom would be perfect--but no Krell on the M/T, thank you.

[SoundsGood]

That's what I have and it worked great.  Check out my photo gallery.