It's interesting that the overall impact of the room reflections seems to be down as much as -10 dB with the Martin Logan speakers. Do you hear a more enveloping sound with the JBL speakers, or any other differences you think got to do with the different dispersion characteristics of the two speakers?
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I don't care about stereo imaging - am I alone. (Poll)
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It's interesting that the overall impact of the room reflections seems to be down as much as -10 dB with the Martin Logan speakers. Do you hear a more enveloping sound with the JBL speakers, or any other differences you think got to do with the different dispersion characteristics of the two speakers?
Opinion, somewhat backed by measures, and biased however you might perceive:
To me, the JBLs spread things out, like a little "out of focus". I suppose deadening the reflections would fix that, but I won't bother.
The panels give a sharp "image". Very small angular differences - like two horn players standing next to each other to one side - seem (or can easily be imagined) to be angularly differentiated.
The JBL gives a "big" image - seems stretched out in comparison - but not very deep.
The ML seem to give a narrower perspective upon switching, then that turns into something just as wide but a little more distant sounding, somehow. I forget that after a while and just enjoy the sharper perspective. I remember once trying to locate the speaker with eyes closed after spinning around to disorient myself, walking toward the panel, and bumping into it while it still sounded three feet away.
The ML will give 180 degree stereo soundfield when playing something with that content - a couple of QSound recordings come to mind. Otherwise not bounded by the speakers with proper recordings.
For best "stereo", both require "head locked in a vise". I don't see how any speaker can't require that.
One evening with Audio Buddy, listening to the JBL vs ML, we weren't even sure if the JBL were in or out of phase with each other, and had to check to be sure. The ML gave no sensation on the same material/test. With pink noise out of phase the ML are very uncomfortable to the ears (rip your ears off), the JBL, just sound even less precise.
So, for high powered (big amps are attached) or "critical listening", the Krells and MLs are fired up. For daily don't care off axis or basic TV use, the JBLs.
If the high frequencies are particularly beamy with the ML, it doesn't bother me since I'm deaf to most of them anyway.
Audio Buddy doesn't complain, and has a similar ML setup at his place (with the CLS speakers), so...
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One last thing:
The panels throw a soundfield phase to the listening position that REW measures (without any special windowing or other measurement tricks) that is "impossibly" (to use someone else's interpretation) flat.
Most measurements I've seen of phase at the listening position look nothing like this:
ML (green) unwrapped because it doesn't need a wrapped presentation
JBL (red) wrapped, else it would just be a line sloping down and mostly off screen and it keeps turning 360 degrees, similar to the woofer (below 200 Hz) of the ML
Both unwrapped, scale expanded:
The JBL (red) gives a measurement typical of all (?) the other phase measurements I've seen posted.
The panels throw a soundfield phase to the listening position that REW measures (without any special windowing or other measurement tricks) that is "impossibly" (to use someone else's interpretation) flat.
Most measurements I've seen of phase at the listening position look nothing like this:
ML (green) unwrapped because it doesn't need a wrapped presentation
JBL (red) wrapped, else it would just be a line sloping down and mostly off screen and it keeps turning 360 degrees, similar to the woofer (below 200 Hz) of the ML
Both unwrapped, scale expanded:
The JBL (red) gives a measurement typical of all (?) the other phase measurements I've seen posted.
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Hi, these descriptions sound like you are listening the JBL too far away. I mean, this is the sort of thing I've been trying to characterize and extend in my setup. I don't know what it is called so I've been attributing the effect to mostly direct/reflected sound ratio. This effect seems to depend on room acoustics and speaker directivity, in general, as I don't know any specifics of it yet. Basically, when listening too far from the speakers the image is flattened and blurred out and literally one step closer the sound opens up, perception of depth increases and all that you describe. I speculate your panels have higher DI than the JBLs so probably have high enough direct/reverberant sound ratio further away, all the way out to your listening spot. The JBL probably has lower DI and if in same room and same listening triangle they might be too far away, outside of the good sound.
Would this make any sense to you? Have you tried smaller listening triangle with the JBLs?
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10 feet, same as the panels.
Yes.
No, although I measured up close once, which definitely reduced the faults I perceive "at distance" in here..
But they do what they do economically and I'm not bothered by them doing that.
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I did listen to the ML nearfield - about a two foot triangle - once a long time ago.
It was scary good.
Cool, and please report back if you try it again. It pretty easy to test, you can leave the speakers where they are, just walk in from the listening position towards midpoint between speakers and listen if the moment of clarity happens before your bump into the wall 
Toe-in some if you feel the highs are lost too much to spot it.
10 feet is too much for my place and system, cardioid + waveguide system I get almost 8 feet, no extra acoustic treatment other than typical living room furnishing.
I suspect many people don't try this and never notice that there could be better sound if listening triangle was smaller. I'm not sure if it's always the case, hence the interest. This could be difference between dome tweeters and horn systems for example "more realistic sound" is just the direct/reflected sound ratio being good or bad. Just trying to increase understanding, as I haven't seen this talked too much on the forums.
Toe-in some if you feel the highs are lost too much to spot it.10 feet is too much for my place and system, cardioid + waveguide system I get almost 8 feet, no extra acoustic treatment other than typical living room furnishing.
I suspect many people don't try this and never notice that there could be better sound if listening triangle was smaller. I'm not sure if it's always the case, hence the interest. This could be difference between dome tweeters and horn systems for example "more realistic sound" is just the direct/reflected sound ratio being good or bad. Just trying to increase understanding, as I haven't seen this talked too much on the forums.
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One more comparison for you at 10 feet:
Unsmoothed frequency response, with "flat" room correction applied
Red JBL
Black ML
Dips are mostly cancellations from reflections.
The hole around 48Hz is the room, left rear corner is open to a larger space, and causes 180 degree phase shift of the standing wave in the bass.
The hole at 220Hz is the front wall reflection.
It doesn't seem to be noticeable, didn't know it was there until measured.
Neither left nor right gives anywhere near that much of a dip.
ML left and right:
Phase, 189 degree difference at marker:
Unsmoothed frequency response, with "flat" room correction applied
Red JBL
Black ML
Dips are mostly cancellations from reflections.
The hole around 48Hz is the room, left rear corner is open to a larger space, and causes 180 degree phase shift of the standing wave in the bass.
The hole at 220Hz is the front wall reflection.
It doesn't seem to be noticeable, didn't know it was there until measured.
Neither left nor right gives anywhere near that much of a dip.
ML left and right:
Phase, 189 degree difference at marker:
sound67
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Since I'm listening mostly to classical music, the stereo image hardly matters. If those recordings were mono I wouldn't be able to tell the difference. There's no cymbal crash coming from the left or a flute solo from the right - it all fuses into one "together" sound.
In the 1960s, even some orchestral music, like the Henry Mancini albums, were artificially engineered to give you that identifiable stereo sound (eg "Hatari"), but those days are long gone. Thankfully.
In the 1960s, even some orchestral music, like the Henry Mancini albums, were artificially engineered to give you that identifiable stereo sound (eg "Hatari"), but those days are long gone. Thankfully.
I feel like OP is perhaps one of those people like those in the visual media who doesnt care too much about color accuracy or particular 3d effects or that sort.. or people who just dont get along with VR type setups...which is fine... I mean like a lot of guys I dont have the best color accuracy so I'm not too fussy on that regard.
I also think that some peoples' perception isnt that well fooled by that "3d immersion" be it visual or audio.
Our world is full of compromise. I live for the day when I can get a dedicated "hi-fi" room but to be honest... 100% of the time I'm doing something else while I'm listening to music... I want to sit at a big desk with a big monitor and I want it feeding a big power amp and a set of speakers and I want to let it rip...
and so in that regard, does it make sense to have a system that is a $10,000 mcintosh amp w/ $10,000 sonus fabers.... or GLM w/ Genelec 8531s?
to me that is kind of like owning a Porsche 911 to pick up my kids or go to the shops... you can do it. But why?
My repertoire so to speak is flacs and mp3s mainly.
Imaging I guess is a nice thing to have but there's aspects that are a tad more important to most? I have listened to speakers that have rubbish imaging in that the sound seemed recessing to the L/R cabinets but these would be very very poor speakers.... eg. Edifiers, pc speakers and outdoor or PA rated speakers but I think just about anything that is mid way decent has ok imaging?
I also think that some peoples' perception isnt that well fooled by that "3d immersion" be it visual or audio.
Our world is full of compromise. I live for the day when I can get a dedicated "hi-fi" room but to be honest... 100% of the time I'm doing something else while I'm listening to music... I want to sit at a big desk with a big monitor and I want it feeding a big power amp and a set of speakers and I want to let it rip...
and so in that regard, does it make sense to have a system that is a $10,000 mcintosh amp w/ $10,000 sonus fabers.... or GLM w/ Genelec 8531s?
to me that is kind of like owning a Porsche 911 to pick up my kids or go to the shops... you can do it. But why?
My repertoire so to speak is flacs and mp3s mainly.
Imaging I guess is a nice thing to have but there's aspects that are a tad more important to most? I have listened to speakers that have rubbish imaging in that the sound seemed recessing to the L/R cabinets but these would be very very poor speakers.... eg. Edifiers, pc speakers and outdoor or PA rated speakers but I think just about anything that is mid way decent has ok imaging?
A correct stereo image doesn't have anything specific to do with what type of recording it contains, it applies the same to a panned multi-mono rock recording as well as to a two-microphone stereo recording of classical music. If the two speakers are set up in a correct stereo configuration and your listening environment doesn't "mask" the room in the recording too much, I bet you will appreciate the stereo image that will give you an insight into the depth and width of the recorded venue.
Interesting. I listen to classical but think the exact opposite: decent stereo image matters a lot to me.
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Hi, the unwrapped phase graph for the JBL looks impossibly wrong to me.
It's just a 2-way with only one crossover, so figure probably 360 degrees max phase rotation for it.
And then some top and bottom ends rolloff rotations.
So anything beyond say 720-900 degrees total rotation is suspect i think.
I would have thought the excessive unwrapped phase is just due to the measurement having a big hunk of constant delay that didn't get removed,
but the stair-steps in the trace make no sense at all.
The only time I've seen something like that, is when a FFT measurement program is using multi-time windows...and it's impulse timing reference is so far off, that it can't make sense of the data. Come to think of it as I write....that could also be due to a very large hunk of constant delay not being removed.....
Anyway, would you recheck...thx.
I think both go hand in hand...
If the stereo speakers are correctly set up you will get a better stereo image that includes a distinct-sounding phantom center image, and when that's in place, you will also get a correct soundstage.
It's no challenge at all to hear different sound objects coming from different places on the horizontal plane between the speakers, for that you can almost place the two speakers however you want in the room. But to be able to hear a correct stereo image and soundstage, the two loudspeakers must be placed so that they form a unified sound with a distinct-sounding phantom center image that will almost sound as good as if a physical center speaker was placed between the main speakers. If you get that phantom image right with an equilateral listening triangle, everything else will fall in place including the full soundstage that contains the correct stereo image width.
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sound67
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I did some engineering myself, recording string quartets for an album that DID make it to market, eventually. Using an A-B stereo setup with pick-up mics for each of the four instruments. Some of the music was very contrapuntal, too. Did the stereo imaging make itself felt? Not really, because I did nothing to increase it artificially.
So no panning was done to the A-B microphones or the point source microphones, you just left them all in the middle of the mix?
The above is what REW measures at 10 feet with no special windowing.
It looks much better if measured up close, but (apparently) can't convey all that goodness across the room without me redecorating, unlike the ML, which seem to do so.
JBL phase with 1/12th smoothing from a meter distant six years ago:
That's not where I listen, so that's not where I normally measure anything to do with speakers.
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sound67
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I did some panning on the pick-up mics, more on the outer-placed instruments (1st violin and cello), less on the centre-placed (2nd violin and viola). Didn't do a whole lot.
Gotcha. Thx.
Looks much more like what's to be expected.
REW simply must have had a hard time latching onto impulse timing at your listening position.
BTW, a couple of asides........I don't like to use gating either.....and nothing to do with meas, am a CLS owner
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I find that comment very odd to say the least.
What orchestral recordings are you listening to, and on what set up, that don't display stereo imaging and sound mostly "mono?"
I listen to tons of orchestral recordings and I'm hard pressed to recall even one that would fit that description. Many of my "best imaging" albums are orchestral.
I typically get a wide spread of orchestral imaging often laid out like a typical orchestra. Instrument sections clearly identifiable in space, soloists the same, the sound of Bolero sweeps around the width of the symphony both tonally as each instrument hands off to another, and spatially, as in a concert.
It was mostly the attempt to recreate the spatial aspects of a symphony in a hall that drove the creation of stereo in the first place!
So I do find your logic that in classcal music stereo image "hardly matters" and mostly sound mono, to be very at odds with reality.
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