A crazy thought: Bi-amping two MC452 amps? Better than .....

[joeinid]

Hi,

I love reading all your thoughts and opinions and appreciate your contributions.

A friend and I were talking and he thinks bi-amping two MC452 amps would be better than probably any other McIntosh amp (except MC2KW's, of course).

Any thoughts on this? I understand my speakers would need two sets of posts and all but one do.

Thanks!

 

[62caddy]

My opinion is that mono operation using normal single wiring to the speakers would be more advantageous, allowing the crossover to utilize maximum available power the most efficiently.

 

[joeinid]

Makes sense, thank you.

 

[kevzep]

Yeah, bi-amp, actively!! None of this "fools bi-amping".....

Except I think it would be nice to have a MC452 on the tops, and using the MEN220 crossover to the low end into a pair of MC601's.....

 

[twiiii]

Bi-amping benefits were being able to place filters before the amps, which were less costly to build, reduced IM distortion, removed power absorbing passive crossovers insuring better coupling between drivers and amps/ If you leave the passive crossovers in and don't use an electronics crossover, the only thing you might gain would be having a choice of using SS or tube amps for a different sound. Altec JBL EV and Bozak loved bi-amping. Bozak for better woofer transient control, and the ability to use either SS or tubes for the mid range and highs and gain efficiency. When Altec, EV and JBL went from horn woofers to ported to reduce size they lost a lot of sensitivity. And to make up the difference and maintain quality Bi-amping was a great answer. Concentrate big power where needed in the bass and use less power for the HF horns, This lowered IM distortion and helped control the woofers. Built in Equalization was added when Altec, JBL and EV changed horn designs to increase directionality, but reduced HF output. As Klipsch stayed with their original designs preferring to give up low frequency response versus high efficiency, bi-amping didn't make much sense. The horns weren't big enough to extend the low range anyway. Now when I used Split La Scalas with MWM-s woofer boxes in discos. The La Scala Hanging and the MWM on the floor using Altec or JBL woofers, Bi am- ping with a 70 hz crossover made perfect sense. The MWM had to be filtered at 35 hz with Eminence woofer, but with JBL and Altec woofers The bass could be extended below 30 HZ and 200 to 300 watts applied with out issue. 100 watts for each La Scala was more than needed. So two Mac 2250/2255 or 7300 on the bottom and one 2250/2255 or 7155/7200 on top made for ideal reproduction in smaller clubs and discos. When there wasn't enough room for two or 4 MWM, then Lansing or Gauss ported boxes with dual 18's or 15's were installed with dual Mac 2500 or 2600 amps. Later on new installations were made with QSC amps with Power Guard when Mac quit selling their Rack mountable units and concentrated on consumers and audiophiles.

 

[unfairlane]

Bi-amping can do a lot even if you`re running passive filters. Like With the Kappa 9`s; the woofers filters here is a tragedy and will make even the bigger amps breathe heavily. To Heavy to be at it`s best in the top-range at the same time.

Btw; through my years of ultimate high-end speaker developement I`ve came to learn that no active filter will sound as good up in the mid- and top section as a first order passive filter built with the right components. For woofers though, active filters are the way to go.

 

[TSmith8605]

Hi,

I love reading all your thoughts and opinions and appreciate your contributions.

A friend and I were talking and he thinks bi-amping two MC452 amps would be better than probably any other McIntosh amp (except MC2KW's, of course).

Any thoughts on this? I understand my speakers would need two sets of posts and all but one do.

Thanks!

You say your speakers only have one set of input posts which means they are not designed to be bi-amped. So if you want to bi-amp them, you will need to engineer your own set up that mimics the existing internal crossover and modify the speakers to allow connection of the two amplifiers to the appropriate places internally. If the speakers are 3-way or more, and you use an external active crossover, you still need to keep parts of the speakers' internal crossover in place or tri-amp them or ??

For an external active crossover, you need to know the crossover frequencies and slopes and the amount of relative attenuation used to match the drivers' loudness and any eq. functions that may be built into the existing internal crossover and you need to mimic all that in the active circuit between the pre amp and power amps.

So do you have the info from the speaker manufacture required to allow you or someone to engineer your own set up?

 

[joeinid]

My SF Strads are single post speakers. My JBL 4367 and Revel Studio2 are both bi-wireable so I'd only bi-amp on those and single amp the Strads.

A friend loves two MC452 as opposed to the MC601s or MC1.2KWs even. I know it's only a passive bi-amp but I'm curious about it and would love to hear it.

My goal in the past was always to get a pair of MC1.2KWs but I don't think anyone has said go for it. They always recommend other McIntosh amps and disparage the 1.2KWs.

I've heard the 1.2KW on 3 occasions and twice I absolutely loved them, the other demo was not great but I can understand why in that case.

Obviously 2 MC452 are more versatile.

I don't want to go crazy with external crossovers or a complicated setup.

 

[62caddy]

If you're not going with external crossovers, there is little benefit to bi amping IMHO - as you will be utilizing the speaker internal crossover network just as you would in traditional wiring. The only difference is that half of your amplification abilities will be dedicated to the MF & HF drivers of which will never need anything close the maximum output of an MC452. Even if those sections used 100w which is virtually impossible, you still have a solid 350 watts excess power that will never be used.

Therefore I stand with my original statement: If you want the maximum amount of available power where it will do the most good, better to use the MC452s in mono with single wiring. Sometimes less is more and more gives less.

 

[joeinid]

Thank you.

So if I understand correctly, on my single post speaker, use one channel per 452 amp (per speaker) if I use two amps?

I know this is getting out of hand and appreciate everyone's opinion. I'm not going to go crazy and just plan on using one stereo amp or a pair of monos.

I'm thinking about starting with one MC452 and enjoy the heck out of it, unless I fall for the new MA9000 integrated.

Thank you gentlemen.

 

[4-2-7]

Therefore I stand with my original statement: If you want the maximum amount of available power where it will do the most good, better to use the MC452s in mono with single wiring.

So if I understand correctly, on my single post speaker, use one channel per 452 amp (per speaker) if I use two amps?

You can not mono block the MC452 as one was able to do with the predecessors like the MC402, MC352.

Even the MC 402 you would need speakers that have low resistance like 4ohms, 2ohms to even benefit from mono blocking them. If you had a 8ohm speakers you would not gain any power.

 

[joeinid]

My speakers are either 4 ohms or 6 ohms.

 

[4-2-7]

A friend loves two MC452 as opposed to the MC601s or MC1.2KWs even. I know it's only a passive bi-amp but I'm curious about it and would love to hear it.

Here your friend must have bi-wired speakers, running one 450watt stereo amp to the uppers and mids, left and right, the other 450watt stereo amp driving the low end left and right. So the end result is no gain what so ever to using one 450watt stereo amp. He still only has 450watts, and no separation of left and right channels, Well unless he's running two outputs L&L to one amp and R&R to the other. But still I wouldn't expect any audible gain doing this setup. More of just showing off and stacking amps to get the same result of using just one.

I don't want to go crazy with external crossovers or a complicated setup.

MC501s MC601s is where you want to go, or even two MC 275s mono blocked. However tubes don't give you as much power, they will putout a lot of heat, and tubes cost a lot.

The 500 & 600 watt mono blocks are dream amps, driving most home speakers past their capability. Over powering the speakers give you plenty of head room to cover all transient peaks in the music without any clipping what so ever. This is audio sound quality when all is said and done.

 

[4-2-7]

My speakers are either 4 ohms or 6 ohms.

Again
You can NOT mono block the MC452 in anyway what so ever. You gain nothing having two of them hooked up to one pair of speakers, you still only have 450 watts. You can go out and buy 4 of them if you want and still will have no gain.

 

[4-2-7]

On the other hand if you had two pairs of identical speakers setup side by side, and two MC452, one driving each pair of speakers at the same time. Your SPL will double in the room. Now I'm not saying this is the best for SQ but if your into rocking out and sending your friends running out of the house, it has it's plusses.

 

[joeinid]

Now that's crazy.

 

[4-2-7]

Now that's crazy.

Who ya calling crazy? LOL, Your not hearing my L250s & 250TIs in this vid but one pair is being driven with my MC501s the other pair with the MC402.

 

[joeinid]

I absolutely love Sarah McLachlan and that sounds great.

Ok, not crazy at all. Wow. Thank you for posting those videos.

 

[62caddy]

That's a shame about mono operation being eliminated. Is nothing sacred anymore?

- An additional pair of identical speakers driven with identical power will increase SPL by 3 dB.

In human hearing, a 10 dB increase is a doubling of SPL.

 

[joeinid]

I just stumbled across this in the MC452 download section. It's a connection diagram for stereo and bi-amp configuration. Pretty cool I think. Can you guys comment?

http://www.mcintoshlabs.com/us/Prod...McintoshDocumentMaster/us/mc452cd1and2-01.pdf

It does show that basically one amp is setup for the highs and the other amp is used for the lows. Each amp has one output per channel and is used to daisy chain the next amp via its output to input.

It was recommended to me to basically use one amp per speaker utilizing both preamp outputs per channel which is vertical bi-amping.

I think the diagram depicts horizontal bi-amping.

That diagram above sort of rekindled my interest. Again I realize it's only passive bi-amping configured this way, but McIntosh does seem to condone the practice. Whether it's to sell more gear or honestly give you better performance is, I assume, a matter of actually trying it. Thoughts?