Judging from the cabinet shapes of your examples, these are all speakers designed to be in corners. The smaller monitors are not.
There is no "one rule" for this... you need to experiment and find what works in your room.
In my room, I noticed on a phase test that the "solidness" of the phantom image varies as I move forwards and backwards in the room. So it's definitely possible that some combination of pathlength and reflections is causing a phase issue at a specific location.
Basically if I sit equidistant between the speakers and I'm three meters away, the phantom is nearly absent; if I move forward a meter it becomes fairly solid.
The Gradient Revolution was one of the speakers that Geddes tested against the Summa, back in the day. The semi hexagonal speaker in this pic.
Many purists start with the assumption that the ideal is to point the speakes so they cross in front of your head. This way the 'sweet spot' is widened a little by the fact that moving your head slightly towards one speaker puts you further off-axis to that speaker, not closer to on-axis, which would shift the apparent source to that speaker due to precedence effect coupled with increasing, not decreasing level from that speaker. With the crossing point in front, precedence effect is partially cancelled by decreasing level. That's the thinking, anyway. I believe the BBC sets things up this way when circumstances permit.
As far as I know, with the speakers in any other orientation the phantom image is compromised.
I thought that only worked for CD speakers?
Patrick, I don't know if it's better to talk about it here or on the other thread. But are you concerned now about the phantom center on the Celilo's?
Patrick, I don't know if it's better to talk about it here or on the other thread. But are you concerned now about the phantom center on the Celilo's?
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Looking at off axis angles, a lot of speakers would still do pretty good at 5 or even 10 degree off axis. So that trick might still work if off axis levels are a fraction lower in SPL than on axis. CD helps to get the balance of the reflected sound similar to the direct sound.
A non CD speaker would create/have more differences in tonal balance of the off axis sound compared to the direct sound.
When you look at seating positions, you're not talking about huge off axis positions unless you want to cover a real large audience.
A non CD speaker would create/have more differences in tonal balance of the off axis sound compared to the direct sound.
When you look at seating positions, you're not talking about huge off axis positions unless you want to cover a real large audience.
As a speaker manufacturer/businessman I would look for "sweet spots" in the business, i.e. value, best bang for the buck. With all the EQ these days it has to be a coax in an infinite baffle or dipole. Dipole is certainly workable, but nothing beats in-wall. It always seemed to me that the proportion of cost devoted to cabinets was outrageous. No box no cost!
I actually did an example of this (dipole coax) once, even impressed myself. Just never did anything with it. So simple that it couldn't be sold at a profit.
Yeah Celilo is basically dead 🙁
Back to the drawing board.
Celilo basically performs about as well as the Kali LP6. Good, but no real directivity control below 1khz. I made the waveguide too small.
I'd still would like to see listening (sweet) spot measurements for the Cosynes as well as the LP6 for educational purposes 🙂. You know, left, right and stereo L+R sum. For a good sum place the microphone in the sweet spot, play a stereo L+R sweep and move the mic increments until you see one clean IR peak. That way it should sum up till the high frequencies like in my example. Unless the room plays havoc with phase.
It could tell us a great deal what the difference between them is, out in the room.
It could tell us a great deal what the difference between them is, out in the room.
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That's basically what we did with the direct vs reflected test, IIRC. Get the mic right in the center so that there is one impulse with both playing, then flip polarity on one speaker and test again.
Here is the thread where we did the Direct vs Reflected measurements. Test procedure and some results are shown. Would be very interesting to see Patrick's Cosyns vs other speakers in the room.
What is the ideal directivity pattern for stereo speakers?
What is the ideal directivity pattern for stereo speakers?
This is what I do and what I recommend. It works exceptionally well, but as stated below:
Basically yes, they do have to be CD. My speakers are toed in such that the listening axis is at about 20 degrees. If the speaker does not have good response at this angle (and +- say 10 degrees) then this technique will not work very well. It's a major advantage of CD that hardly ever gets discussed.
That is not really true in a small room where the speakers might only be say 6 feet apart and toed in at 20 degrees. Some listeners might be as much as 40 degrees off axis. This is true in my setup.
An open baffle with limited HF to the rear - cabinet cost, about 5$. Normally it's hundreds.
The results are posted somewhere here at DIY, but that was back in 2014 so finding it may be tough. Basically it was a 10" B&C coax with a custom crossover. It was not a match in performance to any of my other speakers, but was dirt simple and cheap.
I found some results:
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Dr. Geddes, how come you stick to woofer + waveguide designs instead of MEH? Do you not think there's a diy MEH that could match or best your NS-15 or the Abbey? (if we reduce criteria to not require very high spl). Seems if there were you'd be the one to know how to do it...