Revel Salon2 vs Genelec 8351B - Blind Test Preparations

[DonH56]

That's one of the only things from Toole I find dumb, as the argument is completely wrong. The idea that mono shows more MOS difference -> correctness is not backed by anything. It's the same as making people wear ball and chain during a 100 m sprint because it makes the variance in times larger; it makes more evident who's the strongest, but not the fastest.

It is explained in various papers and his books. And he is a poster here so feel free to call him out. Again.

Shouldn’t an audible difference in the Revel with a speaker stacked on top be measurable? If so, could you measure it both with and without the Genelec on top and see if there is any difference?

I suspect that, given the listening distance and relative size of the speakers, that stacking is the optimum approach in this particular instance. Measuring the stacked and side-by-side configurations should highlight any differences. My previous experience with the AB,AB approach mainly in large'ish dealer demo rooms (where I worked at the time) is that it was very difficult to do a valid stereo test in-room. The image would shift just slightly switching from pair to pair, making it easier to identify them, although realistically the vast majority of the time the differences were so obvious it didn't really matter.

General random thoughts: I would not use EQ or subs to compare speakers. If your goal is to determine which system (speaker plus sub) is best for you under your preferred scheme, then by all means do it that way. Or both ways! (Not my time, might as well do every possible configuration. ) But in general I prefer to minimize variables. I'd guess the Salon2's have an advantage in extended bass (but did not look up the Genelecs) so you may, or may not, want to limit the LF signal to the speakers. I would do it mono since the focus is on speaker performance. Direct sound should not be significantly affected by having a pair, so a mono test is valid (for other reasons see the writings of Toole et. al.), and a pair introduces a myriad of other variables.

FWIWFM - Don

 

[waynel]

That's one of the only things from Toole I find dumb, as the argument is completely wrong.

Have you seen an equal quality controlled study that shows Toole is wrong and that you are right?

 

[echopraxia]

Hi, long distance in large room means you will be listening to the reverberant field (room) instead of the dominance of direct sound of DUTs. Then eq'ing this room response makes comparison pointless.

But that's just me, do what you like!

What, EQing bass below the Schroeder frequency in a room is pointless? That seems wrong.

 

[watchnerd]

How stable is the Genelec sitting on top like that?

Won't cabinet vibrations, amplified by sitting on top of a longer lever, be a potential issue?

 

[echopraxia]

There's no point in doing this in stereo. Stick with one speaker.

I believe hearing a difference in stacked mode will be trivial. Playing pink noise for moment will make it obvious without doing a blind test. So maybe a preference test is on order.

Now I believe the Harman shuffler required 4 seconds to switch. Perhaps incorporating a 4 second delay is enough that vertical stacking no longer becomes obvious whether you are listening to the top speaker or not. Yet it is within echoic memory. Of course Harman tested for preference. Still be good if you didn't know which speaker for preference.

Coincidentally, the miniDSP SHD takes around 4 seconds to switch profiles, during which it is muted. Very convenient in this case.

While your doing this it might be nice to record some music. With the speakers stacked, I'd put the Umik 2 meters from the speakers. Record a few song snippets so we can listen at home. Any vertical shift won't be picked up that way, but the FR or tonality will be. Might be interesting.

Of course I can and will do this in general. But regarding vertical vs horizontal effects, can’t what you’re describing just be revealed via frequency response measurement by the same mic?

There's no point in doing this in stereo. Stick with one speaker.

I‘m getting a lot of mixed signals here. Some say it’s useless in mono, others say it’s useless in stereo.

Shouldn’t an audible difference in the Revel with a speaker stacked on top be measurable? If so, could you measure it both with and without the Genelec on top and see if there is any difference?

Yes, as I mentioned, I will be doing this soon.

I have two questions: What is the objective of the test, and why are you applying EQ?

The objective is to determine which speaker is better. The EQ concept is because when I’ve done blind tests without EQ, people complain that I should have EQ’ed.

 

[watchnerd]

I have two questions: What is the objective of the test, and why are you applying EQ?

I don't understand the point of applying EQ, either.

A good test protocol should reduce as many variables as possible, not add to them.

Adding EQ means any other different EQ in a different situation may get different results.

 

[echopraxia]

How stable is the Genelec sitting on top like that?

Won't cabinet vibrations, amplified by sitting on top of a longer lever, be a potential issue?

Very surprisingly stable. Each Salon2 is somewhere around 150lbs IIRC, and the Genelec have rubber feet that grip strongly.

 

[echopraxia]

I don't understand the point of applying EQ, either.

A good test protocol should reduce as many variables as possible, not add to them.

What part of EQing bass response to match (to remove that as a variable) is confusing?

 

[watchnerd]

The EQ concept is because when I’ve done blind tests without EQ, people complain that I should have EQ’ed.

Huh?

Why is that considered a valid complaint?

 

[watchnerd]

What part of EQing bass response to match (to remove that as a variable) is confusing?

Reproducibility.

Good science means your test should be reproducible by others.

 

[TimVG]

There's no issue with applying filters in the modal region which will likely be extremely similar, if not identical, between the two speakers anyhow anyhow.

 

[watchnerd]

If you tell me you compared 2 speakers using EQ, I'm only going to consider those results valid if using exactly the same EQ.

Any other room would use a different EQ.

 

[sigbergaudio]

What part of EQing bass response to match (to remove that as a variable) is confusing?

Isn't the bass response mainly from the subwoofer, if I understand the setup correctly? Thus it shouldn't really matter if you EQ that or not. But at least surely you shouldn't EQ the part of the frequency range that originates from the speakers? Then you would reduce possible differences, that you were trying to detect in the first place?

 

[echopraxia]

General random thoughts: I would not use EQ or subs to compare speakers. If your goal is to determine which system (speaker plus sub) is best for you under your preferred scheme, then by all means do it that way. Or both ways! (Not my time, might as well do every possible configuration. ) But in general I prefer to minimize variables. I'd guess the Salon2's have an advantage in extended bass (but did not look up the Genelecs) so you may, or may not, want to limit the LF signal to the speakers. I would do it mono since the focus is on speaker performance. Direct sound should not be significantly affected by having a pair, so a mono test is valid (for other reasons see the writings of Toole et. al.), and a pair introduces a myriad of other variables.

So my last blind test of Revel F206 vs Ascend Sierra RAAL Towers was almost meaningless because trivially correctable bass differences of the Revel made the comparison much less interesting (a tie, where Revel F206 won bass and Ascend won treble). In general, bass differences will determine the winner, in my experience, especially if there are no major flaws in the rest.

This is why I would worry about running both full range like that with no bass normalization. But I am certainly open to the idea, especially for these — because both of these very nearly true full range speakers.

 

[echopraxia]

Reproducibility.

Good science means your test should be reproducible by others.

The only way to reproduce bass response across different rooms is to EQ it. Even if someone else used my room, the response would not be reproducible without also perfectly matching the speaker and listening position.

 

[watchnerd]

The only way to reproduce bass response across different rooms is to EQ it. Even if someone else used my room, the response would not be reproducible without also perfectly matching the speaker and listening position.

All you're testing, then, is what people prefer in your room using your EQ.

I don't consider that to be particularly insightful for anyone except you and your room.

Which is fine....but if you're just trying to determine what you like in your room, why do you need a panel of listeners?

 

[echopraxia]

All you're testing, then, is what people prefer in your room using your EQ.

I don't consider that to be particularly insightful for anyone except you and your room.

Which is fine....but if you're just trying to determine what you like in your room, why do you need a panel of listeners?

It’s a realistic representation of what someone with these speakers would do. For sure the Genelecs, as they have room correction built in. You can’t deny that this is fair if this realistically represents how people would setup the speakers.

But that said, I think your point is fair that the bass EQ applied to each should be identical. As you can see from the measurements, the only thing that needs correcting in the bass region is pretty much identical.

Anyways, it’s morning here so I’m about to do some more measurements without the subwoofer. However, it’s still very unlikely no correction will be needed to sound good in this room since this is true for almost all rooms when speakers reach as low as these do.

Why is that considered a valid complaint?

Welcome to posting reviews and product tests online No matter what I do, I guarantee there will be some vocal set of people telling me I’m an idiot for doing it totally wrong. And if I did it their way, another vocal set of people will be telling me I should have done it the other way.

It’s fine, this is just the nature of such things. Such complaints are not even wrong. It’s just because I am forced to make a compromise here, lacking resources comparable to Harman research to perform tests exactly as they do.

 

[watchnerd]

I guess I don't understand the objective of this test.

Given the issues at play (speaker height, EQ), it just seems about as loose as typical audio club "shoot out".

Which can be fun, but there is enough slop in the methodology that there isn't much point in trying to be scientific about it and it won't withstand rigorous scrutiny.

Perhaps better to be humble, have people over for beers, and just take votes on what people like.

 

[Juhazi]

What, EQing bass below the Schroeder frequency in a room is pointless? That seems wrong.

It makes comparison pointless, I said.

What are you trying to explore and find out in the first place? What is your hypothesis?

Sorry but my academic education makes me think this way - you are making huge effort out of which it will be almost impossible to draw conclusions from, at least anything new. We know that these speakers have different response on and off-axis and that will show up as different room response, which most likely will be audiblle.

As well, we know how important bass level is, and perhaps extension too. In this regard I understand using same eq'd subwoofer, so we can null this difference out of evaluation.

I would be quorious to find out if this difference remains when room responses are eq'd similar vs no eq. Also how this difference affects stereo imaging with test signals and music. As well a third speaker with high directivity should be added in list of DUTs. Perhaps fourth which is dipole/panel. In this case the room should have average dimensions and RT. Evaluation per preference ratings, so a totally different scenario...

 

[echopraxia]

I guess I don't understand the objective of this test.

Given the issues at play (speaker height, EQ), it just seems like a typical audio club "shoot out".

Which can be fun, but there is enough slop in the methodology that there isn't much point in trying to be scientific about it and it won't withstand rigorous scrutiny.

Perhaps better to be humble, have people over for beers, and just take votes on what people like.

I disagree this notion that if you can’t control for all variables, you might as well control for none. By this rationale, even Harman should shut down their efforts because they did not in fact control for every possibility. Rather, I think every step towards being more blind or a test (even if not perfect) is a step that will improve the quality of the results.