I don't believe it. I need more power?

[DS-21]

I'm busting the chops of at least one 300w channel? It couldn't be. No wonder those 125w/ch Levinsons sounded weak.

There goes that LED again. I'll be damned.

Ouch. Maybe you should leave the world of consumer amps and find yourself something like a Lab Gruppen or Powersoft multi-kilowatt Class D wonder.

Or more efficient speakers.

Or both (the Seaton Catalyst, for instance).

Except...

Irv, I wouldn't discount the possibility of the preamp or even the recording clipping.

Ditto.

[PENG]

So the power advantage of the lower impedance is totally negated.

It depends on how you look at it. While what you are saying is correct, one could also say that the lower SPL produced by 1W at the lower 4 ohm impedance point (versus at the 8 ohm point) for a speaker specified xdB/2.83V/m is totally negated by the ability of the amp that can double down.

In fact, from sensitivity stand point, I never look at it as an advantage for speakers that offer lower impedance, for the same arguments that you are making, and I hope no one is saying that either. However, I do think it should be obvious to anyone, including yourself, that it is advantageous to have amps that can output more into lower impedance, all the way down to 4 or even 1 ohm.

I'm going to get into an area where I think there is a lot of misunderstanding in these forums. The issue is the relationship to impedance, sensitivity, power demands and efficiency.

A lot of people don't know much about electrical theory beyond Ohm's law.

[TLS Guy]

It depends on how you look at it. While what you are saying is correct, one could also say that the lower SPL produced by 1W at the lower 4 ohm impedance point (versus at the 8 ohm point) for a speaker specified xdB/2.83V/m is totally negated by the ability of the amp that can double down.

In fact, from sensitivity stand point, I never look at it as an advantage for speakers that offer lower impedance, for the same arguments that you are making, and I hope no one is saying that either. However, I do think it should be obvious to anyone, including yourself, that it is advantageous to have amps that can output more into lower impedance, all the way down to 4 or even 1 ohm.

I agree completely with everything you have to say. However I think you have to see the consequences of the power drawn from the amp from the specs.

I believe speaker efficiency is important. For one thing higher efficiency means much cooler voice coils, especially as heating is i squared X R. This means less thermal compression, which is a huge problem at high power. As another consequence there will be less burned drivers, and also longer amp life.

My system really demonstrates that, as the bass drivers are not even sub drivers, the bass amps stay very cool and yet the speakers are really potent in the last two octaves. Movies like Real Steel shake the floor with every step of the robots and you are continually bombarded by sonic shock waves. All this done with plenty of headroom. Personally I have never heard a discrete sub achieve this.

I have said before, the argument the efficiency is not an issue because watts are cheap, in my view does not hold water.

I think in the HT environment, much more attention needs to be payed to efficiency which is related to a degree to sensitivity. Efficiency is not usually specked, and it should be. However if you understand how the sensitivity is specked and have the impedance curve and phase curve, you can come to useful comparisons.

In this regard the difference between my system and the Salon 2s under discussion is a chasm. However that chasm is not immediately obvious.

[PENG]

I agree completely with everything you have to say. However I think you have to see the consequences of the power drawn from the amp from the specs.

I believe speaker efficiency is important. For one thing higher efficiency means much cooler voice coils, especially as heating is i squared X R. This means less thermal compression, which is a huge problem at high power. As another consequence there will be less burned drivers, and also longer amp life.

My system really demonstrates that, as the bass drivers are not even sub drivers, the bass amps stay very cool and yet the speakers are really potent in the last two octaves. Movies like Real Steel shake the floor with every step of the robots and you are continually bombarded by sonic shock waves. All this done with plenty of headroom. Personally I have never heard a discrete sub achieve this.

I have said before, the argument the efficiency is not an issue because watts are cheap, in my view does not hold water.

I think in the HT environment, much more attention needs to be payed to efficiency which is related to a degree to sensitivity. Efficiency is not usually specked, and it should be. However if you understand how the sensitivity is specked and have the impedance curve and phase curve, you can come to useful comparisons.

In this regard the difference between my system and the Salon 2s under discussion is a chasm. However that chasm is not immediately obvious.

No arguments from me at all about the importance of efficiency. May be we can also agree to at least give the Salon 2 credit for having the phase low, like <30 degrees most of the time, reaching 35 and climbing to just below 45 degree briefly where impedance is>6 ohms. Even at 45 degrees, cosine(45)=0.707 and at 6.5 ohm that isn't bad comparing to many others I have seen.

[TLS Guy]

No arguments from me at all about the importance of efficiency. May be we can also agree to at least give the Salon 2 credit for having the phase low, like <30 degrees most of the time, reaching 35 and climbing to just below 45 degree briefly where impedance is>6 ohms. Even at 45 degrees, cosine(45)=0.707 and at 6.5 ohm that isn't bad comparing to many others I have seen.

I agree with that, the phase angles are kind, however the tuning peaks occurring below 20 Hz is strange. It looks like a case of what is know as an extended bass alignment. The response is typical with a rise in output at 100Hz and then a gradual roll off. I find you are better off tuning a little higher and improving spl and efficiency. Those extended bass alignments control drivers poorly.

[Irvrobinson]

I believe speaker efficiency is important. For one thing higher efficiency means much cooler voice coils, especially as heating is i squared X R. This means less thermal compression, which is a huge problem at high power. As another consequence there will be less burned drivers, and also longer amp life.

I'll say one thing for your commentary, you strive for completeness, but with amp life you're really reaching.

My system really demonstrates that, as the bass drivers are not even sub drivers, the bass amps stay very cool and yet the speakers are really potent in the last two octaves. Movies like Real Steel shake the floor with every step of the robots and you are continually bombarded by sonic shock waves. All this done with plenty of headroom. Personally I have never heard a discrete sub achieve this.

Are you serious? I've heard several discrete subs that are powerful enough to make you physically ill, including mine. And I don't get out much.

I have said before, the argument the efficiency is not an issue because watts are cheap, in my view does not hold water.

I think in the HT environment, much more attention needs to be payed to efficiency which is related to a degree to sensitivity. Efficiency is not usually specked, and it should be. However if you understand how the sensitivity is specked and have the impedance curve and phase curve, you can come to useful comparisons.

In this regard the difference between my system and the Salon 2s under discussion is a chasm. However that chasm is not immediately obvious.

On your last point, we agree. The difference in efficiency between your system and the Salon 2 is likely a chasm. The Salon 2 is a commercial product created by a huge corporation to have an extended frequency response in a relatively small enclosure with attractive styling. Well, at least great styling in a technical sort of way. Even a Soundscape 12 is pretty ugly and ungainly by comparison. Your design is in another segment altogether.

On the other hand, for all their faults, which includes a high price that includes a lot of dealer margin in it, the Salon 2s continue to impress me. Just today they passed an a very difficult test. My wife invited over a band colleague to practice some jazz, her on the drums, Bob on the Steinway. I knew Bob wanted to hear my audio system, and I wanted to demo it for him *before* they started playing. Almost all audio systems sound less impressive after you hear live music. But that was not to be the case today, and they practiced for 90 minutes first.

The Revels acquitted themselves extraordinarily well in the demo, and we were playing similar music. Even I was surprised. Obviously the issues caused by commercial recording engineers were laid bare, but what we heard on the Revels was comparable to the live instruments. None of us were at all disappointed. We were just hearing other people play.

I know the Revels are a compromise, a very commercial compromise. But they sure are a good one. Even if those 150Hz 4th order crossovers are a travesty of good design.

[Irvrobinson]

Ditto.

Unlikely. The preamp is from Benchmark Media and the recording is from Telarc. I think it is far more likely to be amp clipping.

[TLS Guy]

Unlikely. The preamp is from Benchmark Media and the recording is from Telarc. I think it is far more likely to be amp clipping.

I'm certain it will be the amp clipping.

I'm sure you sub can make you physically ill, however I don't get to hear many subs, and the ones I do are awful.

The subs in the MPR studios are awful along the Genelec monitors.

Dealers seem not to stock potent subs round here.

Only my good friend Phil has a really high end system and he has a B & w sub, which is the worst excuse for a low frequency reproducer I have ever heard in a high end system.

This system has a bass with a very light touch and so when a huge bass note sounds it gives that real how it is feeling. In movies the shock waves seem to come from nowhere and slam you with force and the floor moves, in fact I think I could collapse the floor or blow out a window if I was careless.

As far as efficient speakers and amp life that is not a stretch. All semiconductors have a temp/life curve. The more current you demand from an output stage the shorter the life will be, especially if you send it into clipping. Pumping high currents into speakers is basically output stage abuse.

I have a couple of amps doing sterling work at our other residence, that I have never taken the covers off in over forty years.

Your point about the constraints of commercial design is well taken even at the higher price brackets. I'm well aware that to produce these speakers and bring them to market, the price tag would be four or five times the cost of the Salon 2s

So there I will leave it.

[AcuDefTechGuy]

Only my good friend Phil has a really high end system and he has a B & w sub, which is the worst excuse for a low frequency reproducer I have ever heard in a high end system.

My system really demonstrates that, as the bass drivers are not even sub drivers, the bass amps stay very cool and yet the speakers are really potent in the last two octaves. Movies like Real Steel shake the floor with every step of the robots and you are continually bombarded by sonic shock waves. All this done with plenty of headroom. Personally I have never heard a discrete sub achieve this.

Apparently you have not personally heard a great sub.

Or perhaps our definition of great bass/sub is just different.

[TLS Guy]

Apparently you have not personally heard a great sub.

Or perhaps our definition of great bass/sub is just different.

No, I probably haven't, but they are not plentiful round hereabouts, since Internet sales seem dominant.

However if it was more forceful, that what is have it would blow out the windows.

When I did the calcs, on this rig, I realized I had to be careful as these lines could actually reproduce an explosive shock wave and demolish the room. That actually made me break out in a sweat, and I had to make so it would not happen by accident.