I thought I owed it to those involved in two of my larger builds to give a longer term review of these two speakers having lived with them for a few years, and over the last few weeks having done level matched, sighted and unsighted AB comparisons (which was hard work but fun!).
If you are unfamiliar with these two builds here are the threads:
The XBush Mark 2. A synergy/Unity horn of spherical proportions
Great Balls of Prestige
The differences are fairly obvious. One is a two way synergy horn with good controlled directivity, excellent measurements and using SB acoustics middle of the road (but very good) drivers. The other is a four way high output low diffraction, but more typical design using extremely high end drivers from VOLT, scanspeak and SB acoustics.
The four way system does have better than average directivity as the volt dome VM752 is horn loaded and hands over to the the scanspeak 7000 ring radiator which also has narrower directivity than a 'normal dome' almost like it is in a shallow waveguide, but it is obviously not as well controlled or tight as the synergy horn.
This is my newly completed listening room. The two large 'pictures' behind are 200mm fibreglass slab behind acoustic printed cloth. And you can see some of the ceiling treatments which are similar but with a 100mm gap behind to enhance low frequency absorption. I also have bass trapping in two corners to reduce some of the room modes. The room is 4mx5m with a listening distance of 2.80m. This photo is slightly 'fisheyed' and taken behind the listening position so don't worry about the apparent 'toe-in'.
If you are unfamiliar with these two builds here are the threads:
The XBush Mark 2. A synergy/Unity horn of spherical proportions
Great Balls of Prestige
The differences are fairly obvious. One is a two way synergy horn with good controlled directivity, excellent measurements and using SB acoustics middle of the road (but very good) drivers. The other is a four way high output low diffraction, but more typical design using extremely high end drivers from VOLT, scanspeak and SB acoustics.
The four way system does have better than average directivity as the volt dome VM752 is horn loaded and hands over to the the scanspeak 7000 ring radiator which also has narrower directivity than a 'normal dome' almost like it is in a shallow waveguide, but it is obviously not as well controlled or tight as the synergy horn.
This is my newly completed listening room. The two large 'pictures' behind are 200mm fibreglass slab behind acoustic printed cloth. And you can see some of the ceiling treatments which are similar but with a 100mm gap behind to enhance low frequency absorption. I also have bass trapping in two corners to reduce some of the room modes. The room is 4mx5m with a listening distance of 2.80m. This photo is slightly 'fisheyed' and taken behind the listening position so don't worry about the apparent 'toe-in'.
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The longer term listening without any controls and sometimes in different rooms, led me to favor the 4-way system over the synergy horn, but like with any audio experience I wondered how much of this was due to me liking the visual appeal of my newer build, and the knowledge that it used more expensive drivers.
So last week with the help of my wife, I moved both systems into the same room, placed them as close as possible to each other (and switched them around to ensure position wasn't the determining factor) and did a series of listening sessions.
I use a Gustard U12 as digital interface which I sent up to output SPdif to the miniDSP-DA8 (which controlled the synergy horn crossover - a flat phase 500hz crossover) and AES balanced output to the miniDSP 4x10hd running at 96 plugin (which controlled the 4-way system with standard LR4 crossovers at 90, 600, and 3000hz) at the same time.
This meant I could have both systems running at the same time and use a remote control to mute one miniDSP and then the other - this allowed seamless switching between the two speakers - almost instantaneous - and made it so much easier to compare one to the other.
I level matched with my SPL meter at the listening position - tried various levels using pink noise from 75spl up to 85 spl average.
Given both systems were controlled using miniDSP - this also allowed me to adjust the frequency response at the main LP - so I tried to ensure they both had my preferred house curve within a dB of each other from 20-20,000hz (this took the longest time to sort out!).
So I felt that this was the only way I could properly qualify what my longer term, more relaxed, sighted impressions were all about and I hope this meant I would be listening more to the speaker dispersion and driver qualities rather then frequency response.
So last week with the help of my wife, I moved both systems into the same room, placed them as close as possible to each other (and switched them around to ensure position wasn't the determining factor) and did a series of listening sessions.
I use a Gustard U12 as digital interface which I sent up to output SPdif to the miniDSP-DA8 (which controlled the synergy horn crossover - a flat phase 500hz crossover) and AES balanced output to the miniDSP 4x10hd running at 96 plugin (which controlled the 4-way system with standard LR4 crossovers at 90, 600, and 3000hz) at the same time.
This meant I could have both systems running at the same time and use a remote control to mute one miniDSP and then the other - this allowed seamless switching between the two speakers - almost instantaneous - and made it so much easier to compare one to the other.
I level matched with my SPL meter at the listening position - tried various levels using pink noise from 75spl up to 85 spl average.
Given both systems were controlled using miniDSP - this also allowed me to adjust the frequency response at the main LP - so I tried to ensure they both had my preferred house curve within a dB of each other from 20-20,000hz (this took the longest time to sort out!).
So I felt that this was the only way I could properly qualify what my longer term, more relaxed, sighted impressions were all about and I hope this meant I would be listening more to the speaker dispersion and driver qualities rather then frequency response.
I did the sessions, on my own with me switching back and forth sighted, with my wife with her switching back and forth, and sighted and unsighted.
My wife also took part, as did my two children (7 and 10 years old) to get some younger ears on the case!
It was interesting that we all agreed - only very occasionally on a few specific tracks were preferences different.
The overwhelming preference was for the four way more tradition design. But let me try to pick out why I think this is.
My wife also took part, as did my two children (7 and 10 years old) to get some younger ears on the case!
It was interesting that we all agreed - only very occasionally on a few specific tracks were preferences different.
The overwhelming preference was for the four way more tradition design. But let me try to pick out why I think this is.
Obviously it is very difficult to work out the reasons for these preference, but I think there were a few main factors - one of the largest was room interaction. The more traditional wider directivity speaker 'painted' the room more. This undoubtedly resulted in more envelopment. I thought imaging and clarity would suffer but it was actually also better with the wider dispersion speaker - whether some of this is due to my room treatments helping I do not know - it is now a fairly well sorted listening room.
Next, drivers - there is no doubt to me, contrary to my science and 'measurements first' beliefs that despite the excellent measurements of my synergy speaker, the drivers in the 4 way systems dig deeper into detail retrieval and simply 'sound better'. I cannot quantify this with any REW measurements or explain it at present - this was most evident to me with the mid-high frequency detail and realism.
Lastly the crossovers - the synergy horn is a two way minimum phase crossover, whilst the balls of prestige use 4-way standard LR crossovers. I think this mainly affected the soundstage (although directivity may have something to do with this too).
With the 4-way system the soundstage was behind the speakers and had immense depth, whilst the synergy horn system had a more forward presentation - more like headphones but in front of you rather than either side. Whilst experimenting with various crossover slopes and types I feel this is often a attribute of LR4 crossovers.
Did the synergies sound poor - no absolutely not - if I wasn't able to switch back and forth almost instantly I think you would adjust to the presentation very quickly and not recognise or miss the differences. They are excellent speakers.
Could all this just be preference and what we as a family are used to listening to - i.e. relatively standard directivity, multiway, LR4 crossover speakers.....maybe - but without a doubt the 4-way speakers felt more 'real' in presentation - a bit like headphones allow you to hear immense detail and tone, but the presentation is much less real than a good stereo speaker setup (apart from some biaural recordings of course).
Next, drivers - there is no doubt to me, contrary to my science and 'measurements first' beliefs that despite the excellent measurements of my synergy speaker, the drivers in the 4 way systems dig deeper into detail retrieval and simply 'sound better'. I cannot quantify this with any REW measurements or explain it at present - this was most evident to me with the mid-high frequency detail and realism.
Lastly the crossovers - the synergy horn is a two way minimum phase crossover, whilst the balls of prestige use 4-way standard LR crossovers. I think this mainly affected the soundstage (although directivity may have something to do with this too).
With the 4-way system the soundstage was behind the speakers and had immense depth, whilst the synergy horn system had a more forward presentation - more like headphones but in front of you rather than either side. Whilst experimenting with various crossover slopes and types I feel this is often a attribute of LR4 crossovers.
Did the synergies sound poor - no absolutely not - if I wasn't able to switch back and forth almost instantly I think you would adjust to the presentation very quickly and not recognise or miss the differences. They are excellent speakers.
Could all this just be preference and what we as a family are used to listening to - i.e. relatively standard directivity, multiway, LR4 crossover speakers.....maybe - but without a doubt the 4-way speakers felt more 'real' in presentation - a bit like headphones allow you to hear immense detail and tone, but the presentation is much less real than a good stereo speaker setup (apart from some biaural recordings of course).
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So all in all, I thought I would prefer the synergies - to me they are a less compromised speaker design - well controlled directivity, single point source, only 2 way - so only one crossover at 500hz to muck about with the signal, and really good objective measurements across the board.
I was therefore surprised and a little disappointed by my findings. It may be I have missed an obvious confounding factor, or that I simply prefer wide dispersion speakers to narrow. But I know which ones I will be keeping in my listening room.
Interestingly there was a similar face off of the JBL M2 - large horn and CD top with excellent controlled directivity 2-way, versus the Revel Salon 2 - more typical TMWWW three way. This was done in a very controlled blinded test well organised and run.
I would also have put money on the M2s winning, but the wider dispersion Revels won.....
Speaker Shootout - two of the most accurate and well reviewed speakers ever made - Page 12 - AVS Forum | Home Theater Discussions And Reviews
I was therefore surprised and a little disappointed by my findings. It may be I have missed an obvious confounding factor, or that I simply prefer wide dispersion speakers to narrow. But I know which ones I will be keeping in my listening room.
Interestingly there was a similar face off of the JBL M2 - large horn and CD top with excellent controlled directivity 2-way, versus the Revel Salon 2 - more typical TMWWW three way. This was done in a very controlled blinded test well organised and run.
I would also have put money on the M2s winning, but the wider dispersion Revels won.....
Speaker Shootout - two of the most accurate and well reviewed speakers ever made - Page 12 - AVS Forum | Home Theater Discussions And Reviews
Thanks for doing this comparison, I had wondered.
You are very welcome - very subjective and only my personal thoughts. Take it as it is!
Really interesting, thanks a lot for all the information given here (and even before...).
I would be really interested seeing some REW dual tone intermodulation distortion measurement between the 2 ways VS 4 ways at frequencies around your 2 way crossover. Should it be a key ?
Interesting link about that point : Intermodulation Distortion
"Unlike harmonic distortion, intermodulation distortion levels do correlate well with perceived sound quality, the lower the better. "
"In the graphs below, one can see the advantage of introducing a midrange driver. The midrange intermodulation distortion is reduced by 10-15 dB."
I would be really interested seeing some REW dual tone intermodulation distortion measurement between the 2 ways VS 4 ways at frequencies around your 2 way crossover. Should it be a key ?
Interesting link about that point : Intermodulation Distortion
"Unlike harmonic distortion, intermodulation distortion levels do correlate well with perceived sound quality, the lower the better. "
"In the graphs below, one can see the advantage of introducing a midrange driver. The midrange intermodulation distortion is reduced by 10-15 dB."
Interesting. Esp the fact that the loss of point source didn't cause you major sonic pain as one would have thought that would show up.
Regarding the soundstage depth this is highly dependant on frequency response and any dips in the 2-5kHz region will push the soundstage back. So the cross-overs on the 4 way are possibly causing that depth. Whether stage depth is an artificial construct is an interesting question, but given that Linkwitz always put that dip into his crossovers it can be considered part of the 'adjust to taste'.
I think you are trying to match the subjective findings to dispersion. You might be right, but you might not. .
With the revels vs M2s I haven't read the whole thread, but I do wonder if the fact that the Salons are voice to sound 'nice' and the M2s are brutally revealing studio tools might mean that the less accurate speaker won? Dunno I can't afford either (or fit them into my house)
Regarding the soundstage depth this is highly dependant on frequency response and any dips in the 2-5kHz region will push the soundstage back. So the cross-overs on the 4 way are possibly causing that depth. Whether stage depth is an artificial construct is an interesting question, but given that Linkwitz always put that dip into his crossovers it can be considered part of the 'adjust to taste'.
I think you are trying to match the subjective findings to dispersion. You might be right, but you might not.
. With the revels vs M2s I haven't read the whole thread, but I do wonder if the fact that the Salons are voice to sound 'nice' and the M2s are brutally revealing studio tools might mean that the less accurate speaker won? Dunno I can't afford either (or fit them into my house)
Interesting. Esp the fact that the loss of point source didn't cause you major sonic pain as one would have thought that would show up.
Regarding the soundstage depth this is highly dependant on frequency response and any dips in the 2-5kHz region will push the soundstage back. So the cross-overs on the 4 way are possibly causing that depth. Whether stage depth is an artificial construct is an interesting question, but given that Linkwitz always put that dip into his crossovers it can be considered part of the 'adjust to taste'.
I think you are trying to match the subjective findings to dispersion. You might be right, but you might not.
With the revels vs M2s I haven't read the whole thread, but I do wonder if the fact that the Salons are voice to sound 'nice' and the M2s are brutally revealing studio tools might mean that the less accurate speaker won? Dunno I can't afford either (or fit them into my house)
Agree with a lot of the above - as I stated above - I feel LR4 does push the soundstage back - I think this is down to the power response like you.
Dispersion and envelopment is definitely a factor too though - just speak to the open baffle crowd!
Regarding the differences between the M2 and the revel - I thought the same as you - but here are the "Spinorama Measurements" from both the Salon2 and the M2:
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I agree - this could be some of it -but horn loaded speakers are renowned for reducing IM due to the better air coupling and therefore lower cone travel!?
Revels Vs M2, 4 ways Vs 2 ways again... ^^
But i suspect never as much as more ways (?). Neumann in previous link show a example of about -10/-15 db reduction adding a way.
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High diffraction - almost floor to ceiling bookshelves, etc. some bass trapping in corners.
You right right about the 'dip' - I bet that is the LR4 TM crossover affecting the power response.
If so, and this does subjectively improve sound quality, then why fight it?
ok the rear wall should be just what the horns need to create the diffusion required. And yes at the end of the day if it sounds good no point trying to fight it. But would be interesting to DSP a shallow dip into the synergies
I should note at this point I have a vested interest in trying to unpick this. I've been tempted to try something similar once I'm moved into a bigger place and brood 2 are bigger, but always wondered about the fact that, if you can get down to 500Hz with one driver do you lose anything going to a straight 2 way with say a 12" bass unit below. Effectively you could get most of the synergy goodness (bar the packaging advantages) for a lot less work.
I should note at this point I have a vested interest in trying to unpick this. I've been tempted to try something similar once I'm moved into a bigger place and brood 2 are bigger, but always wondered about the fact that, if you can get down to 500Hz with one driver do you lose anything going to a straight 2 way with say a 12" bass unit below. Effectively you could get most of the synergy goodness (bar the packaging advantages) for a lot less work.
I see!! I can't blame you I too thought this was going to be the best speaker I could possibly build so was disappointed that we all prefer the 'normal speaker' - I can have a play - I should be honest and say that I kinda did this already - we did the tests first off as they were originally voiced- then I spent ages getting the same frequency response in the listening window for both sets of speakers - this involved a fair bit of manipulation with the synergies as they excited different modes etc. So the on axis and + - 20 degree ish windows were very similar. I will try putting a dip in though - as obviously power responses were not matched.
However, it wasn't just the soundstage that was different, envelopment was different as was detail retrieval, and the 'realism' (whatever that is!). So I don't think this is just frequency response or dispersion dependent - I also think the drivers themselves contributed to the outcome (something I have not really subscribed to before).
My personal experience is similar to bushmeister! I have heard many highly directive speakers like large synergys and 15" coaxials, but I prefer the sound that good low-directivity multiway speakers give in a normal living room. All of these have been well recognized and well-measuring speakers with low distortion.
I have measured sound of many speakers in many different rooms, and it is astonishing, that RT30 time is usually longest around 2-3kHz (except for low bass). This might be one reason why bbc-dip sounds good!
My sound preference comes from listening to acoustic live performances and I am rather critical of the timbre of piano, ac. guitar, violin etc. but not interested in sharp imaging. I understand that many people like sharp imaging which reveals all tricks done in recording and mixing studio for pop and similar "born in studio" music.
I have read the thread M2 vs. Revel Salon too, and isn't it funny that Toole said that he still has Salon2's at home, because he likes the sound so much!
Listening and enjoying music is the main goal for hifi speakers, not certain "ideal" technical performance!
I have measured sound of many speakers in many different rooms, and it is astonishing, that RT30 time is usually longest around 2-3kHz (except for low bass). This might be one reason why bbc-dip sounds good!
My sound preference comes from listening to acoustic live performances and I am rather critical of the timbre of piano, ac. guitar, violin etc. but not interested in sharp imaging. I understand that many people like sharp imaging which reveals all tricks done in recording and mixing studio for pop and similar "born in studio" music.
I have read the thread M2 vs. Revel Salon too, and isn't it funny that Toole said that he still has Salon2's at home, because he likes the sound so much!
Listening and enjoying music is the main goal for hifi speakers, not certain "ideal" technical performance!
