[schues]

Hi,

I need help deciding on a Bryston amplifier.  I have M&K 150 speakers.  Speakers are 4 Ohms, recommended power rated of ~200, and sensitivity 91 dB.  I do 80% movies & 20% music.  I will be pairing the amp with an Emotiva XMC-1 pre / pro.

I can't decide on a 9BSST2 (5 channel) or a 6BSST2 (3 channel) along with a 3B for the rears.  Thoughts?  Is the 6B too "powerful" for the M&K 150s.  The 6B is rated at 300 watts.  Thoughts?

Thanks!
Adam

[Mag]

IMO it depends on whether you are using a sub and how loud you listen at. Bass takes power to produce, so if you are using a sub then that takes the strain off the amps.

If I recall the 9B SST2 has about 150 watts. In my system that would result in occasional clipping. So the 6B & 3B SST2 would be my choice. Then again if you do not listen at loud spl the 9B should be sufficient.

[CanadianMaestro]

Not sure what the price differential is between 6B and 9B.
But if it's not a significant factor for you, then go with more power.
Future-proof. IMHO.

"Moderation is a fatal thing. Nothing succeeds like excess"
- Oscar Wilde

[schues]

The real question ... is the 6BSST2 too powerful for the MK 150s?   It's rated at 300 at 8 Ohm and 500 at 4 Ohm.  The MK are rated at 200 at 4 Ohm. 

[Armaegis]

It's better to have too much power than not enough. You're more likely to damage speakers by underpowering them.

[G Georgopoulos]

The real question ... is the 6BSST2 too powerful for the MK 150s?   It's rated at 300 at 8 Ohm and 500 at 4 Ohm.  The MK are rated at 200 at 4 Ohm.

ouch,500w amp into 200w spk busted 

It's better to have too much power than not enough. You're more likely to damage speakers by underpowering them.

haha,yes i'm sure you heard that somewhere,the reality is the other way around 

[Armaegis]

An underpowered amp means you will drive the amp into clipping when pushing at louder volumes. When this happens, it's a bit like feeding a square wave through your speakers. This is extremely bad for the speakers (in fact worse than driving them over their rated power level) because a transducer does not naturally behave in that manner. Trying to "hold" the driver out at the clipped output to mimic the square waveform is a bit like feeding bursts of DC current through the voice coil. Of course, that just means you've now turned your voice coil into a heater, which as you can imagine is a very undesirable outcome.

So I repeat, it is better to be overpowered than underpowered. Now of course, you don't want to be driving past your rated speaker limits in the first place, but going over with a clean waveform is significantly better than clipping out underneath.

[G Georgopoulos]

An underpowered amp means you will drive the amp into clipping when pushing at louder volumes. When this happens, it's a bit like feeding a square wave through your speakers. This is extremely bad for the speakers (in fact worse than driving them over their rated power level) because a transducer does not naturally behave in that manner. Trying to "hold" the driver out at the clipped output to mimic the square waveform is a bit like feeding bursts of DC current through the voice coil. Of course, that just means you've now turned your voice coil into a heater, which as you can imagine is a very undesirable outcome.

So I repeat, it is better to be overpowered than underpowered. Now of course, you don't want to be driving past your rated speaker limits in the first place, but going over with a clean waveform is significantly better than clipping out underneath.

haha,look what makes you think that low power amp clips and and high power doesn't,what makes you think that low power is effected by a square wave and a high one not,look at it this way, suppose both amps dont clip,where is the problem?,i'll tell you! ok! RMS power is the represented power of DC in AC, put that (500w) amp into 200w spk and come back and tell me nothing happened!ok,cheers

[Armaegis]

Let's say you have speakers with 86dB/W sensitivity and max rated power at 300W. Now let's say you want enough headroom to hit 110dB peaks in the music. Simple calculations tells us we need 256W. That's running pretty close to our max power, but that's ok.

The problem occurs if you're using an underpowered 100W amp. Trying to push up to those required peaks is beyond what the amp can handle. Best case scenario is if the amp has soft clipping protection which rounds out the waveform, but chances are it doesn't. When you overdrive an amp, oftentimes you're hitting the voltage rails or the output current devices are maxing out. Either way, you're going to get a clipped output which as I've explained before is very bad news for your speakers. It doesn't matter that this clipping is occurring below the speaker's rated power handling; feeding high level clipped waveforms into the speakers is not good for them.

Now take a 500W amp, it can handle those peaks no problem. The output remains clean, and the speaker is not being tasked with unusual behaviour. We remain below the maximum rated speaker levels so all is fine.

[CanadianMaestro]

I'm with Armagaeis. Experience with my own 90dB, 4-6 ohms speakers tells me that a max power ceiling benefits my ability to hear music sound more effortless at crescendos and sharp swings of dynamics, than a lower-powered, but still substantial amp. My B100 integ amp did a very good job at driving my speakers. But I still heard some "straining" at the louder peaks. With a 4B-SST2, things really improved. But I still had that occasional sense of stress whenever the treble was sustained or the dynamic swings were too quick for my drivers to cope with. Then came the 14B. With that beast, no sense of compressed dynamics whatsoever. Power is good. The more the better. Throw out the textbook and calculations.

Beware of Trojan Horses here. Or Trojan Trolls.
 

[CanadianMaestro]

haha,look what makes you think that low power amp clips and and high power doesn't,what makes you think that low power is effected by a square wave and a high one not,look at it this way, suppose both amps dont clip,where is the problem?,i'll tell you! ok! RMS power is the represented power of DC in AC, put that (500w) amp into 200w spk and come back and tell me nothing happened!ok,cheers

I've done this. Result? Smoother dynamics, less harsh treble at louder volumes, tighter bass. My speaker manufacturer in Austria consistently recommended amps with loads more power than its 200W listed recommendation.

The key is to listen responsibly, knowing full well the limits of your drivers. Most music doesn't need anywhere near a sustained 500W level of power to sound good. But it's mandatory to have power reserves for those very brief moments when the music demands peak delivery in a controlled manner. Control and supply to achieve smooth driver performance. That's what the best powered amps do.

[James Tanner]

On tests we have conducted a transient can ask for 10 times the power for a very short period on transients so having that reserve power is important.

james

[gtaphile]

The real question ... is the 6BSST2 too powerful for the MK 150s?   It's rated at 300 at 8 Ohm and 500 at 4 Ohm.  The MK are rated at 200 at 4 Ohm.

I have owned both a 9BSST and a 6BSST powering 4 ohm speakers and I can tell you first hand that the 6B was smooth sailing and the 9B had difficulty with the load. 

As mentioned by others here  - there is no such thing as too much power. If the price is anywhere close between the amps the speaker is better off with an amp that is cruising to support the load at whatever volume you chose over one that is having difficulty even at low listening levels.   

[Armaegis]

Thanks for the backup guys

[CanadianMaestro]

 

[schues]

Price really isn't an issue.  Both are priced the same.

9BSST2 is 140 at 8 Ohm (200 4 Ohm)
6BSST2 is 300 at 8 Ohm (500 4 Ohm)

I was thinking about spending the money on the 6BSST2 and just getting a low end 2 channel to power my surrounds.  I don't think spending a lot on the surrounds is necessary.  The front 3 channels are the most important. 

[Armaegis]

Get the 6B and find an old 2B on the used market!

[zoom25]

Exhibit A: https://www.youtube.com/watch?v=4JWgmv92fQk

Exhibit B: https://www.youtube.com/watch?v=ygBP7MtT3Ac

Exhibit C: https://www.youtube.com/watch?v=qEhWMicidQU

Exhibit D: https://www.youtube.com/watch?v=SiMHTK15Pik

[CanadianMaestro]

Exhibit A: https://www.youtube.com/watch?v=4JWgmv92fQk

Exhibit B: https://www.youtube.com/watch?v=ygBP7MtT3Ac

Exhibit C: https://www.youtube.com/watch?v=qEhWMicidQU

Exhibit D: https://www.youtube.com/watch?v=SiMHTK15Pik

So, your point is...?   

[zoom25]

So, your point is...?   

https://www.youtube.com/watch?v=-dJolYw8tnk