What do you think about the B+W 705 S2?

[Art Vandelay]

Sound Power is definitely not the curve that any loudspeaker would want to set as a primary performance goal.

So what's the point of a uniform on and off axis response? Both are measuring the same quantity (acoustic power) but the on/off axis measurements are more specific. If a uniform on and off axis response is your primary goal then linearity of sound power is your ultimate primary performance goal by default.

And of course it matters in reality too and is why JA of Stereophile is always quick to examine off axis behaviour when he measures an irregularity on the listening axis. As an experienced reviewer he's aware of the subjective consequences.

Sure, to what extent the relationship between the acoustic power response and the on-axis response will affect the response in the listening chair, or vicinity thereof, is definitely determined by the room's acoustic properties as well as the listening distance, but not surprisingly a typical domestic speaker is usually designed to operate within a typical listening environment with various parameters assumed and taken into account.

All this very confusing to me. Maybe I should just trust Dennis.

Or your own two ears. They're the final arbiters.

 

[Dennis Murphy]

I was once of that view too but having heard a few demos of phase / time correction I'm now more of the view that it is 'perceived' and definitely preferred when the spectrum is time and phase coherent.

My take on it is that time and phase coherence of the primary wavefront results in a more life-like presentation where everything seems to snap into place and focus. Of course it can't be readily described in usual terms such as 'tone' or 'timbre' etc, and is not related to neutrality or accuracy in the strict sense, but to a large extent I think it's what still separates the live performance from (even) the best high fidelity systems.

I've participated in a number of those demonstrations, and I've never heard a difference. And I've compared a transient perfect active version of one of my speakers with the stock 4th order, and it was a total coin toss. Floyd says could participants could hear a little difference on a test signal rather than on music, but they just thought the the sound was a little different--there was no preference for one or the other. Also, you have to be exactly on the design axis to get a transient perfect response from the speakers. Any slight movement will break down any effect that might exist.

 

[Good4it]

Yes my own ears are the best way but I haven’t heard the BMRs or the BWs or the Joseph Audios or the Focals. So what’s a guy to do except ask others who maybe have.

 

[shadyJ]

So what's the point of a uniform on and off axis response? Both are measuring the same quantity (acoustic power) but the on/off axis measurements are more specific. If a uniform on and off axis response is your primary goal then linearity of sound power is your ultimate primary performance goal by default.

And of course it matters in reality too and is why JA of Stereophile is always quick to examine off axis behaviour when he measures an irregularity on the listening axis. As an experienced reviewer he's aware of the subjective consequences.

Sure, to what extent the relationship between the acoustic power response and the on-axis response will affect the response in the listening chair, or vicinity thereof, is definitely determined by the room's acoustic properties as well as the listening distance, but not surprisingly a typical domestic speaker is usually designed to operate within a typical listening environment with various parameters assumed and taken into account.

Sound power measures the total acoustic energy emanating from the speakers, so all energy coming from the speaker from every direction. However, the directivity vs frequency matters. You could build a speaker to have a flat sound power response and still sound terrible if all that energy is being directed to odd angles. Sound power does not hold anything near the importance of direct response and lateral axis responses. You can not equate them at all. Sound power is a good metric for predicting how a loudspeaker will behave in-room below the transition frequency. Above the transition frequency, it isn't really meaningful, and I would only look at sound power above bass frequencies only for academic curiosity, not as any kind of useful gauge for a loudspeaker's sound character.

 

[shadyJ]

Yes my own ears are the best way but I haven’t heard the BMRs or the BWs or the Joseph Audios or the Focals. So what’s a guy to do except ask others who maybe have.

One thing you can do is just get a speaker that had a flat direct response and a smooth off axis response. That way you can simply equalize the sound character to whatever your taste is. It's much more difficult to predictably equalize a speaker with an odd response, especially when the off-axis response does not match the on-axis response. In a sense, getting a speaker with a flat direct axis response and smooth off-axis response is like buying clay that you can easily sculpt into any shape you want, but EQing something with an erratic response is like buying a finished sculpture and trying to turn it into another sculpture, not easy.

 

[Art Vandelay]

I've participated in a number of those demonstrations, and I've never heard a difference. And I've compared a transient perfect active version of one of my speakers with the stock 4th order, and it was a total coin toss. Floyd says could participants could hear a little difference on a test signal rather than on music, but they just thought the the sound was a little different--there was no preference for one or the other. Also, you have to be exactly on the design axis to get a transient perfect response from the speakers. Any slight movement will break down any effect that might exist.

Point taken.

Another problem is that the room reflections will contain non time aligned reflections, given that no speaker is remotely close to being a point source (isotropic) radiator. So even if there is merit it can only be fully realised at one location and within an anechoic environment. Most of the 'demos' are probably sufficiently flawed to be of little value in determining whether or not 'transient perfect' is a worthwhile pursuit.

Fwiw, David Wilson claims that not all people are equally sensitive to time domain distortions, but in general believes that we all become increasingly sensitive as we get older. Of course that's just his personal opinion based on personal experience.

 

[Art Vandelay]

Sound power measures the total acoustic energy emanating from the speakers, so all energy coming from the speaker from every direction. However, the directivity vs frequency matters. You could build a speaker to have a flat sound power response and still sound terrible if all that energy is being directed to odd angles. Sound power does not hold anything near the importance of direct response and lateral axis responses. You can not equate them at all. Sound power is a good metric for predicting how a loudspeaker will behave in-room below the transition frequency. Above the transition frequency, it isn't really meaningful, and I would only look at sound power above bass frequencies only for academic curiosity, not as any kind of useful gauge for a loudspeaker's sound character.

On this point I guess we have to agree to disagree to some extent.

 

[<eargiant]

Are they worth $2500? Anyone heard them?

Only you can determine if they are worth it but if I were in the market again for stand mount speakers in that price range the 705S2 would probably be my top choice. I wouldn't hesitate to buy them if I didn't already own the CM5 and 805D2. They both tick a lot of boxes for me. To my ears, they do so much right and very little wrong. These are speakers you can live with a long time and the more you live with them the more you appreciate what they can do.

To give you a price-point comparison, I recently re-auditioned the KEF LS50 and the KEF R300 which are both about half the retail cost of the 705S2. I much preferred the LS50 even taking into account their reduced bass output. I find the R300 to be muddier than the LS50. I then switched to the 805D3 in the same room and it was a dramatic step in the direction I like. Very, very similar to the presentation of my D2s, even from a distance. There was no comparison to either, you are now in a different league.

The 705S2 are going to be closer to the presentation of the 805Ds than the LS50 which as good as they are, are left in the dust as are the larger KEF R300.

Just my opinion which is what the OP asked for.

 

[shadyJ]

On this point I guess we have to agree to disagree to some extent.

The point your are disagreeing with is that it matters what direction the speaker is projecting sound?

 

[Dennis Murphy]

Fwiw, David Wilson claims that not all people are equally sensitive to time domain distortions, but in general believes that we all become increasingly sensitive as we get older. Of course that's just his personal opinion based on personal experience.

Well, in that case if I can't hear it, nobody can.

 

[Art Vandelay]

The point your are disagreeing with is that it matters what direction the speaker is projecting sound?

I think you're saying that I'm not of the view that listening-axis response matters as much as power response.

Actually I'm not suggesting that at all. My point was based on the presumption that a listening axis response that's within +/- 3dB limits is relatively easy to achieve these days. Most if not all half decent speakers manage to achieve that. Given that the vast majority of hi-fi systems are set up in relatively lively rooms, it's going to be the power response that mostly determines how the speaker will sound, and speakers can and do vary wildly in that regard.

 

[shadyJ]

I think you're saying that I'm not of the view that listening-axis response matters as much as power response.

Actually I'm not suggesting that at all. My point was based on the presumption that a listening axis response that's within +/- 3dB limits is relatively easy to achieve these days. Most if not all half decent speakers manage to achieve that. Given that the vast majority of hi-fi systems are set up in relatively lively rooms, it's going to be the power response that mostly determines how the speaker will sound, and speakers can and do vary wildly in that regard.

Back in the old days, speaker manufacturers actually used to use something like power response curves as a guide to speaker performance from testing their speakers in reverberant chambers. No manufacturer has done that for decades for very good reason. The reason is that what happens directly above and directly below the speaker is not nearly as important as angles that the listener will either catch directly or as a early reflections.

 

[AcuDefTechGuy]

So what's the point of a uniform on and off axis response?

I agree that you should buy speakers that sound good to you.

But just to clarify, does this mean you don’t think that it’s important for speakers to have a linear/flat on-axis and smooth off-axis ?