The reviewer's reviewing system.

[Robh3606]

Hello Spaz

I know you were not one of the bashers. I agree that you really need both measurements and subjective evaluations to get anything meaningful. As far as the reviewers systems unless you are in their room in is really hard to judge what their kit really sounds like. you could have a guy with what looks like a run of the mill system and have it sound fantastic because he really is talented at optimizing what he has. Could easily go the other way as well have a spectacular list and it sounds awful. No easy answers Glad you are happy with your speakers. Not to crazy I use a very similar response curve so I knew how the balance would be. The driver integration is amazing I am very happy with them.

Rob

 

[Detlof]

i wonder what the right measure of beer is for the best listening expirience..?

Depends on your weight and how seasoned you are

 

[microstrip]

Hello Micro

What is there to decide?? What critical question you want to do HT you need 105db minimum for reference level 115db subs. You want orchestral at row 10 you do what 110db for peaks. You don't need any computer modeling to figure it out. You take the -6db rule used for doubling distance in an open space, convert it to 3db per Toole in his book, and just plug in the numbers. Simple as that.

Why does everything have to made so complicated when it's not.

This is simple stuff you can get out of almost any book on the subject.

http://www.doctorproaudio.com/doctor/calculadores_en.htm

Rob

Rob,

Again you are giving me very strong arguments. You give numbers for HT, a very different subject from stereo, and are ignoring the real room, and the interaction between speaker and amplifier.

When we are doing just one simple guess we can use approximate values. However when computing complex things the number of variables increase and errors propagate in calculations making the result completely misleading. The difference between a 100 and 200W amplifier is just 3dB!

Did you realize that the nice audio calculator you are referring to uses the -6dB rule you have warned us that should not be used to closed spaces? Do you thing they are being sponsored by amplifier manufacturers wanting to sell more powerful amplifiers?

 

[microstrip]

(...)
I think it is relevant because I see measurements get bashed all the time by people who simply have no clue about what is possible. (...)

I purchased my Revel Peforma 206's based solely on their measurements. Never heard them till I got them home. They are exactly what the measurements told me they would be. Fine sounding speakers.

Rob

No Rob. I am being very careful about the use of standard measurements because I (and you, BTW) know how they should be used and their intrinsic limitations in high-end.

Happy to know you are pleased with your speakers. But please remember that most audiophiles do not use speakers with controlled directivity as advised by Toole and you seem to like. Or amplifiers that are perfect voltage sources.

 

[DaveyF]

Hello Spaz
As far as the reviewers systems unless you are in their room in is really hard to judge what their kit really sounds like. you could have a guy with what looks like a run of the mill system and have it sound fantastic because he really is talented at optimizing what he has. Could easily go the other way as well have a spectacular list and it sounds awful.

Rob

While that is very true, I would believe that the likelihood of a reviewer ( particularly one who regularly reviews very high end gear) getting a much better idea as to how the reviewed piece sounds, is far higher with ancillary gear that is commensurate ( or 'superior') to the gear under review.

 

[thedudeabides]

I purchased my Revel Peforma 206's based solely on their measurements. Never heard them till I got them home. They are exactly what the measurements told me they would be. Fine sounding speakers.Rob

Glad they worked out for you.

Wonder how many others have done this?

 

[thedudeabides]

From a review standpoint if it doesn't have measurements I won't even read it.

Interesting, I am the exact opposite. Never look at the measurements in a review and have rarely used them over the last 40 years or so in my purchasing decisions.

 

[Purite Audio]

Interesting, I am the exact opposite. Never look at the measurements in a review and have rarely used them over the last 40 years or so in my purchasing decisions.

!
Keith

 

[Robh3606]

Again you are giving me very strong arguments. You give numbers for HT, a very different subject from stereo, and are ignoring the real room, and the interaction between speaker and amplifier.

Hello Micro

There is no difference between HT and Stereo for determining what your peak SPL is. The room in not really relevant. As far as the interaction between the amp and the speaker the assumption is the amplifier can drive the load and deliver full power across it. Not to far fetched. In actuality using the rated 8 ohm RMS wattage is conservative as it doesn't account for speaker impedance and amplifier headroom. You would have to have the smarts to account for that when you enter it into the calculator. I think most of us are more than capable of doing that. Also keep in mind 3db of error is simply not going to be audible at those higher SPL's during peaks. It's an approximation as you are going to want headroom above what your chosen max is so going conservative will pretty much guarantee you can hit your number.

When we are doing just one simple guess we can use approximate values. However when computing complex things the number of variables increase and errors propagate in calculations making the result completely misleading. The difference between a 100 and 200W amplifier is just 3dB!

OK but 3db is just audible and I can't see anyone doubling up the power to get from 112 to 115 on peaks.

Did you realize that the nice audio calculator you are referring to uses the -6dB rule you have warned us that should not be used to closed spaces? Do you thing they are being sponsored by amplifier manufacturers wanting to sell more powerful amplifiers?

Yes and all you have to do is divide the distance correction factor by 2 and add that too the calculated peak SPL. I don't care who sponsors it the concept is correct from a technical standpoint.

Rob

 

[Robh3606]

While that is very true, I would believe that the likelihood of a reviewer ( particularly one who regularly reviews very high end gear) getting a much better idea as to how the reviewed piece sounds, is far higher with ancillary gear that is commensurate ( or 'superior') to the gear under review.

Hello Davey

I see your point but I would pay more attention to what loudspeakers he is using. Everything gets filtered through them.

Rob

 

[microstrip]

There is no difference between HT and Stereo for determining what your peak SPL is. The room in not really relevant. As far as the interaction between the amp and the speaker the assumption is the amplifier can drive the load and deliver full power across it. Not to far fetched. In actuality using the rated 8 ohm RMS wattage is conservative as it doesn't account for speaker impedance and amplifier headroom. You would have to have the smarts to account for that when you enter it into the calculator. I think most of us are more than capable of doing that. Also keep in mind 3db of error is simply not going to be audible at those higher SPL's during peaks. It's an approximation as you are going to want headroom above what your chosen max is so going conservative will pretty much guarantee you can hit your number.

OK but 3db is just audible and I can't see anyone doubling up the power to get from 112 to 115 on peaks.

Yes and all you have to do is divide the distance correction factor by 2 and add that too the calculated peak SPL. I don't care who sponsors it the concept is correct from a technical standpoint.

Rob

Your assumptions violate usual audio knowledge, IMHO people will have to consider them with care. Reading that maximum stereo peak SPLs are absolutes and should be the same for stereo and HT, that the room is not relevant in choosing an amplifier and that we can assume that the amplifier can always drive full 8 ohm power across the load with the same quality and that doubling the power is just audible, is new to me and means we have very different views on these matters. Too many absolutes. Readers will pick what they prefer.

IMHO end users will want correct usable answers, not "concepts" that are "correct from a technical standpoint" but give misleading practical results. YMMV.

 

[Robh3606]

No Rob. I am being very careful about the use of standard measurements because I (and you, BTW) know how they should be used and their intrinsic limitations in high-end.

Hello Micro

I don't see any limitations that are restricted to the high end. They are what they are be it entry level or SOTA they simply don't change.

Happy to know you are pleased with your speakers. But please remember that most audiophiles do not use speakers with controlled directivity as advised by Toole and you seem to like. Or amplifiers that are perfect voltage sources.

OK but not sure what you mean? Me using that type of speaker is a personal preference. There certainly are reviewers that do use or have used Revels as their reference??

Rob

 

[thedudeabides]

!
Keith

Whatever that means. By now, most people should know where I am at on the O V S continuum.

And suffice to say, we are obviously at opposite ends of that scale.

 

[DaveyF]

Hello Davey

I see your point but I would pay more attention to what loudspeakers he is using. Everything gets filtered through them.

Rob

Rob, I think everything gets filtered through all the gear in the system. The speakers just happen to be at the end of the chain. An audio system is only as good as its weakest link. Loose information at the source...and you will never make it up at the speakers. Therefore, everything is important.

 

[Robh3606]

Hello Micro

I don't see where they do at all.

Reading that maximum stereo peak SPLs are absolutes and should be the same for stereo and HT,

I didn't say they were the same or absolutes aside from the reference level for HT What I said is they are calculated the same way. Plain and simple pick you number and go from there.

that the room is not relevant in choosing an amplifier and that we can assume that the amplifier can always drive full 8 ohm power across the load with the same quality and that doubling the power is just audible

The room has absolutely nothing to do with picking an amplifier aside from size. From a power standpoint it all boils down to what SPL you need. Sorry but what amplifiers that you know can't power a pair of speakers over the entire normal audio bandwidth into an 8 ohm load? I would like to avoid them. Doubling the power on peaks will be barely audible. Really think you can hear a difference between 112 vs 115??

IMHO end users will want correct usable answers, not "concepts" that are "correct from a technical standpoint" but give misleading practical results. YMMV.

Well we have to agree to disagree. This is a hobby after all but from my point of view people do not take the time to educate themselves about the technical issues and that is a big mistake as I see it. There is way to much Voodoo in this hobby and forums like this tend to perpetuate it. What do you think professional installers do?? If you want practical results the best way to get them is using the correct technical methods.

Rob

 

[Robh3606]

Rob, I think everything gets filtered through all the gear in the system. The speakers just happen to be at the end of the chain. An audio system is only as good as its weakest link. Loose information at the source...and you will never make it up at the speakers. Therefore, everything is important.

Sure your right but I have always viewed the speakers as universally the weakest link in the chain. You may not.

Rob

 

[rbbert]

If by HT you mean 5.1 or 7.1 (or x.2), you can't really make loudness calculations in quite the same way as for 2.0 or 2.1 stereo. Perhaps if you are only discussing subwoofer level, but otherwise the very random amount of musical information (and volume) that goes to the center and surrounds of HT may or may not end up affecting your calculations. In neither case (stereo or HT) can room effects (absorption, reflection, reinforcement, cancellation) be ignored. And 3 dB is a pretty significant volume difference IMO; try making a mix CD where the average volumes of different cuts (which otherwise have similar dynamic range) varies by 3 dB; I think you'll feel like constantly wanting to change the volume.

 

[microstrip]

Hello Micro

I don't see where they do at all.
I didn't say they were the same or absolutes aside from the reference level for HT What I said is they are calculated the same way. Plain and simple pick you number and go from there.

Exactly - the point is which number you pick. If we do not have an unique firm reference maximum level for stereo where do you start?

The room has absolutely nothing to do with picking an amplifier aside from size. From a power standpoint it all boils down to what SPL you need. Sorry but what amplifiers that you know can't power a pair of speakers over the entire normal audio bandwidth into an 8 ohm load? I would like to avoid them. Doubling the power on peaks will be barely audible. Really think you can hear a difference between 112 vs 115??

Exactly - size also means area and this means reflexion, diffusion and absorption coefficients at various frequencies - room gain. Amplifiers can put their power in 8 ohm loads - but most will not be able to put it all in real speakers!

Well we have to agree to disagree. This is a hobby after all but from my point of view people do not take the time to educate themselves about the technical issues and that is a big mistake as I see it. There is way to much Voodoo in this hobby and forums like this tend to perpetuate it. What do you think professional installers do?? If you want practical results the best way to get them is using the correct technical methods.
Rob

Unfortunately you were not able to teach us these famous correct technical methods, just a few flawed examples that need corrections. And yes, again, the typical consumers are not as knowledgeable as "professional installers".

And we still have the problem of inconsistency of the little available data - see for example for the Revel Ultima Salon the manufacturer says 2 86.4 dB SPL with 2.83 V @ 1m ; Stereophile states 86 db and Soundstage NRC measurements says : Sensitivity: 84.25dB (averaged 300Hz-3kHz, 2.83V/1m).

What is the figure we shall pick?

 

[beaur]

I purchased my Revel Peforma 206's based solely on their measurements. Never heard them till I got them home. They are exactly what the measurements told me they would be. Fine sounding speakers.

Rob

Just to throw another wrench in this thread, how is the above statement any different than anyone in the blind listening/measurement crowd saying those of us who choose components subjectively have an expectation bias. For every yin there is a yang and if all you do is correlate something to a measurement then you most likely will expect it to sound like that. I bring this up not to denigrate but to show that this isn't as simple as many would like it to be. In fact I consider that lack of simplicity a "fun" part of this hobby. I am also one who hasn't heard a true hi-end system lately that wasn't good unless there was something wrong ie, a cartridge misaligned, tube bad or wires crossed.

 

[Robh3606]

If by HT you mean 5.1 or 7.1 (or x.2), you can't really make loudness calculations in quite the same way as for 2.0 or 2.1 stereo. Perhaps if you are only discussing subwoofer level, but otherwise the very random amount of musical information (and volume) that goes to the center and surrounds of HT may or may not end up affecting your calculations. In neither case (stereo or HT) can room effects (absorption, reflection, reinforcement, cancellation) be ignored. And 3 dB is a pretty significant volume difference IMO; try making a mix CD where the average volumes of different cuts (which otherwise have similar dynamic range) varies by 3 dB; I think you'll feel like constantly wanting to change the volume.

Hello rbbert

Well for HT you have a known reference level so that's what you would set-up for. When you do the base set-up you want all 5 or 7 speakers to have the same SPL averaged over the available listening positions. You can still figure out what your peak capability is. As far as the subs it can get a little dicey depending how many, placement and how much mutual coupling you have going on when you have more than one. And again you can figure out what you max SPL will be. Its possible just not as easy.

As far as 3db for an average I agree it's significant but I am taking about instantaneous peak levels well over 100db That's where all your power is going that last 3db of level where you go from 100 to 200 watts in the blink on an eye. Do you think you could tell the difference 112 vs 115?? Do you think you would find it significant or just darn loud in both cases.Get your hands on a peak reading digital SPL meter, it is very informative you won't believe how loud some peaks are and can be. Funny thing is they don't sound as loud as you would think they should sound compared to the average. They are just too short in duration.

Rob