Running MC452 as monoblocs

[o0OBillO0o]

Hi!

Take a peak at the McIntosh XR100 manual, http://www.mcintoshlabs.com/us/Prod...Name=McintoshDocumentMaster/us/xr100om-01.pdf

Turn to page 13.

You'll see what looks like two MC452, 450 watt per channel,stereo amps hooked up in horizontal bi-amp configuration. While not truly physical separation in channels in the diagram, I am sure one could switch to a vertical biamp config and then call it monobloc.

Now, can some one tell me why this method is the example given by McIntosh? Is this a prefered method?

At anyrate, I like it and it makes me want to buy two MC452s.

 

[4-2-7]

You can't mono block the MC452.

A quick look at the drawing it looks like they are bi-amping using two 452s

 

[o0OBillO0o]

You can't mono block the MC452.

A quick look at the drawing it looks like they are bi-amping using two 452s

Define monobloc.

There is bridging and mono, meaning one, channel. Left and Right channels, independently, can be run by a stereo amp as one, mono, channel. There is several points of discussion in the picture. Users could use one amp for the bass and one for the treble OR one amp for Left and Right Bass and the other for Left and Right Treble. Either way you are using two MC452 amps.

I want to know why McIntosh chose this example to diagram.

 

[4-2-7]

Define monobloc.

There is bridging and mono, meaning one, channel. Left and Right channels, independently, can be run by a stereo amp as one, mono, channel. There is several points of discussion in the picture. Users could use one amp for the bass and one for the treble OR one amp for Left and Right Bass and the other for Left and Right Treble. Either way you are using two MC452 amps.

I want to know why McIntosh chose this example to diagram.

Bridging or parallel moneing a stereo amp doubles the output of the amp.

Bi-amping this way gives you 450 just like if one amp was used.

As far as why mac shows this layout is just to give examples, oh and then you could buy another amp.

 

[o0OBillO0o]

Bridging or parallel moneing a stereo amp doubles the output of the amp.

Bi-amping this way gives you 450 just like if one amp was used.

As far as why mac shows this layout is just to give examples, oh and then you could buy another amp.

What I am seeing is 450 watts for the bass and 450 watts for the treble. So That's 900 watts per channel.

This example looks excessive and unnecessary, but awesome. Why include it as the "Example?"

 

[whoaru99]

What I am seeing is 450 watts for the bass and 450 watts for the treble. So That's 900 watts

Doesn't work that way.

As shown, it appears the amps are running full range and allowing the speaker crossover to do the routing of content to the low and mid/high drivers. This means the power distributes according to how the speaker crossover passes off the content.

For example, if the crossover is such that 75% goes to the lows and 25% to the mid/high, then the power distributes that way regardless if there is one or two amps connected.

One amp: 450W, 75% for bass, 25% for mid/high = 450 total

Two amps:
450 x .75 for bass = ~337W
450 x .25 for treble = ~113W
Still equals 450w total

Another way to look at it, a better way actually, is by voltage swing. To put more power into any given speaker the voltage to the speaker must be increased. Two 450 watt amps connected this way do not provide materially more voltage swing to the speaker than one 450 watt amp.

Bridged would different matter, because both channels are then essentially in series which makes voltage swing equal to sum of the two channels. More voltage swing equals more power.

 

[o0OBillO0o]

Well I disagree.

We know nothing of the XR100's Crossover. Even in an example case, crossovers distribute power and frequencies ?

Look at it this way, what if there was four single channel 450 watt amps and there is a mid treble array and a bass array?

That is what I see with two 450 watts per channel with 2 MC452 amps, connected to pair of XR100 speakers with high and low inputs.

Why would McIntosh put this in the manual? They are much more informed of their product than anyone of us.

No one has been able to articulate why this example would be beneficial.

 

[4-2-7]

Well I disagree.

We know nothing of the XR100's Crossover. Even in an example case, crossovers distribute power and frequencies ?

Look at it this way, what if there was four single channel 450 watt amps and there is a mid treble array and a bass array?

That is what I see with two 450 watts per channel with 2 MC452 amps, connected to pair of XR100 speakers with high and low inputs.

Why would McIntosh put this in the manual? They are much more informed of their product than anyone of us.

No one has been able to articulate why this example would be beneficial.

Point 1
Ok

Point 2
Call Mac

Point 3
The only benefit is you are Bi-wiring the speakers.

What I am seeing is 450 watts for the bass and 450 watts for the treble. So That's 900 watts per channel.

But this is absolutely not the case.

If you take the MC402 that amp can be bridged parallel mono but only with speakers of 6ohms and lower as the 402 taps are 8,4 and 2 ohms.

Output impedance connections of
1 ohms, 2 ohms and 4 ohms are provided. If the Loud-
speakers' Impedance is in-between the available con-
nections, use the nearest lower impedance connection.

Specifications
Power Output Stereo
Minimum sine wave continuous average power output per
channel, all channels operating is:
400 watts into 2 ohm load
400 watts into 4 ohm load
400 watts into 8 ohm load

Power Output Mono Parallel
Minimum sine wave continuous average power output is:
800 watts into 1 ohm load
800 watts into 2 ohm load
800 watts into 4 ohm load
Output Load Inpedance
2, 4 or 8 ohms (Stereo Mode)
1, 2 or 4 ohms (Mono Mode)

Taking the XR100 speaker
IMPEDANCE NOMINAL
8 Ohms

While you can parallel mono the MC402 something you cant do with the CM452, you will still have only 400 watts per channel but it would be a true mono block as in separation of channels.

 

[kevzep]

Doesn't work that way.

As shown, it appears the amps are running full range and allowing the speaker crossover to do the routing of content to the low and mid/high drivers. This means the power distributes according to how the speaker crossover passes off the content.

For example, if the crossover is such that 75% goes to the lows and 25% to the mid/high, then the power distributes that way regardless if there is one or two amps connected.

One amp: 450W, 75% for bass, 25% for mid/high = 450 total

Two amps:
450 x .75 for bass = ~337W
450 x .25 for treble = ~113W
Still equals 450w total

Another way to look at it, a better way actually, is by voltage swing. To put more power into any given speaker the voltage to the speaker must be increased. Two 450 watt amps connected this way do not provide materially more voltage swing to the speaker than one 450 watt amp.

Bridged would different matter, because both channels are then essentially in series which makes voltage swing equal to sum of the two channels. More voltage swing equals more power.

Yes, ^^ This.

The MC452 does not have the facility to run mono parallel or in bridge mode. I know, I am sitting right next to one and looking at the rear of it....

 

[kevzep]

Hi!

Take a peak at the McIntosh XR100 manual, http://www.mcintoshlabs.com/us/Prod...Name=McintoshDocumentMaster/us/xr100om-01.pdf

Turn to page 13.

You'll see what looks like two MC452, 450 watt per channel,stereo amps hooked up in horizontal bi-amp configuration. While not truly physical separation in channels in the diagram, I am sure one could switch to a vertical biamp config and then call it monobloc.

Now, can some one tell me why this method is the example given by McIntosh? Is this a prefered method?

At anyrate, I like it and it makes me want to buy two MC452s.

That actually achieves nothing apart from using more amp channels, you have full range going both amp channels which is then filtered by the passive crossover...
Fools bi-amping is what it is.....
To make it worthwhile you need to use an active crossover.

 

[whoaru99]

Well I disagree.

As I fully expected. That is pretty much the universal response when people are first presented with the information provided.

Usually most people get it after a while. Took me a bit to grasp it too. I even did my own experiments because I was sure those telling me 1 and 1 does not equal 2 were full of "it".

This is not to say there might not be some sonic benefit, but power delivered is not.

 

[o0OBillO0o]

As I fully expected. That is pretty much the universal response when people are first presented with the information provided.

Usually most people get it after a while. Took me a bit to grasp it too. I even did my own experiments because I was sure those telling me 1 and 1 does not equal 2 were full of "it".

This is not to say there might not be some sonic benefit, but power delivered is not.

It is the universal response. Ha!

I still don't see it.

The MC452 is a two channel amp, with 450 watts per channel. Having two MC452 amps gives you 4 channels with 450watts per channel.

I could plug a four channel preamp into these amps and have four independent channels. Is everyone with me?

Now, forget mono, forget bridging, we all know what those are and do. If you aren't sure there is probably a wikipedia article on both subjects.

When you use a McIntosh C2500, a MEN220, and 2 MC452 amps, a pair of biamp-able speakers and follow the directions listed in the manuals of each product; users will will have a system with no short coming of output.

What we can't agree on is that 4 channels of amplification for a total of 1800 watts, 900 watts total per speaker, 450 watts per treble and bass array is some form of the truth.

Folks, this configuration is in the McIntosh manual, so I am not making it up. There is no wattage listed, but if I'm doing this right then we may have an idea. Further I can almost see Chuck Hinton's or Ron Cornelius's response. I'll send the query out and will share with you all.

For the record I am not angry mad or frustrated, I think this is very funny.

 

[whoaru99]

It doesn't matter what McIntosh shows in their manual in this regard (and yes, I looked at it). With all due respect to the brand, the engineers, and McIntosh owners, they do not have special exemption from Ohm's Law and all that.

Frankly, if someone from McIntosh comes back with a materially different reply regarding the power delivered to the speakers it will be disappointing.

What I posted before, and others have agreed with, is true. It's your choice to sort it out or remain in disbelief.

 

[o0OBillO0o]

It doesn't matter what McIntosh shows in their manual in this regard (and yes, I looked at it). With all due respect to the brand, the engineers, and McIntosh owners, they do not have special exemption from Ohm's Law and all that.

What I posted before, and others have agreed with, is true. It's your choice to sort it out or remain in disbelief.

So how do you interpret the graphic on page 13?

 

[whoaru99]

Interpreted exactly as described in the initial post you don't believe.

 

[damacman]

Well, look at it like this . . . one MC452 can deliver 450 wpc from 20Hz to 20kHz. Two MC452s passively biamped can deliver 450 wpc from 20Hz to 20kHz. Effective power is the same. Now, insert an electronic crossover network between the two and things change.

I'll agree that there can be sonic benefits from doing to as well so it's not all bad.

 

[whoaru99]

Also, if you are going to post a reply from McIntosh please include your question(s), verbatim. Context is everything.

 

[o0OBillO0o]

Also, if you are going to post a reply from McIntosh please include your question(s), verbatim. Context is everything.

Absolutely!

 

[o0OBillO0o]

That actually achieves nothing apart from using more amp channels, you have full range going both amp channels which is then filtered by the passive crossover...
Fools bi-amping is what it is.....
To make it worthwhile you need to use an active crossover.

That is my going in position, I thought the diagram was odd but cool at the same time.
Is there any benefit?
This is why I am confused.


added: AND if I need an active crossover, that should be in the manual. Explicitly. "Use an Active crossover"

It does say:
"
Note: When the XR100 Loudspeaker System is driven by two amplifiers, the output levels of differ- ent model amplifiers connected to the Loud- speaker System must be adjusted to achieve a proper balance between the low and midrange/ high frequencies reproduced. This adjustment is best achieved through the use of audio test equipment operated by a qualified installer.

"

 

[o0OBillO0o]

Start response/

Hi o0OBillO0o,

Well, bi amping vertically would still put 450 watts to woofers and 450 watts to the highs, which is not the same a s running MONO, which would put 900 watts to all ( except the MC452 does not go in mono.) as the woofer needs about 10 x the power the mids and highs do, providing more power to woofers would be advantages over bi-amping. ( and yes, the crossover does distribute power, by raising the impedance at frequencies where you want less power, all speakers work this way.)


The reason to suggest horizontal bi-amping is related, the WOOFERS need all the power, in horizontal, if the effort of driving the woofers causes the amp any stress, this would show up as increased distortion, however, a bit of distortion is quite difficult to hear in a woofer ( and they are typically about 3% to start with).


With the woofer amp doing all the hard work, the upper amp, connected to the mids and highs, is totally loafing and will stay super clean, which is more important in the mid and highs, where the drivers are cleaner and more sensitive to distortion, and in the frequencies where you can more readily detect distortion.


In a vertical bi-amp, each amp is still driving a woofer and more likely to be stressed on hard to drive speakers, if the amp is stressed, the audible artifacts of that stress will be in the mids and tweets as well, so,


Horizontal bi-amping will provide cleaner sound.


Does that help?


Chuck Hinton


McIntosh, Wadia and Snell Tech Support
McIntosh Sales Admin
Toll Free: (888)-979-3737 X311
Binghamton New York - "The Original Silicon Valley"


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Question/Comments: Hi there! Take a peak at the McIntosh XR100 manual, http://www.mcintoshlabs.com/us/Prod...Name=McintoshDocumentMaster/us/xr100om-01.pdf Turn to page 13. You'll see what looks like two MC452, 450 watt per channel,stereo amps hooked up in horizontal bi-amp configuration. While not truly physical separation in channels in the diagram, I am sure one could switch to a vertical biamp config and then call it monobloc. Now, can some one tell me why this method is the example given by McIntosh? Is this a prefered method? At anyrate, I like it and it makes me want to buy two MC452s. I also have a running thread of what makes me laugh out loud, below. http://www.audiokarma.org/forums/index.php?threads/running-mc452-as-monoblocs.692504/You guys are the best, o0OBillO0o

/End response

Well, we all learn something. Thanks team.