The Portal....a controlled dispersion tripole

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And hey ! Dont get overboard with 'lobing' in the speaker. The room takes care of that :) Cannot hear it. Its a speaker to listen, not to measure. Maybe you measure each side separately in order to set the cross over, though.

Yes, I know when using the room as part of the system it's near impossible to trust measurements, but I will certainly time align the drivers and cross over as low as possible. I think I may be able to go lower than people think because I'm actually using 1 1/2 drivers per side (considering the front firing panel is sharing half the amplitude)
 
Only above baffle step?
Hmmm.....

Because below baffle step the speaker looses directivity and approaches omni. Then signals will leak aronud the box.
In my single speaker stereo I deal with it using the matrix x=0.5 which actually turns it as a benefit. I use no dela so it becomes as vector summation at low freqs.

On the second thought, try the delay for center. Worst it can do is to make low freqs to appear twice at the listening position. Remember that also the rear elements leak to fron at low freqs whoch makes them to act like direct sound. What you will get is two times the direct sound plus two times the reflections. Now THAT is spaciosness :D
 
I was talking about applying delay to center.
I'm not sure if delay will effect poorly on lower frequencies.
The speed of sound is constant at all frequencies.
I know what you are saying, that the wavelengths are more phase coherent the larger the sound waves, But delay would still only improve coherence regardless of the wavelength.
 
That's completely false. Put an MTM with big vertical nulls on its side, and walk across the room.

You are missing the two extra MTMs playing simultaneously aimed towards the front room corners. The walls be highly reflective as a design feature.

Instead, put two inherently lobeless speakers in a conventional stereo triangle playing a same signal and repeat your walk. You will understand why these threads exists. Read my signature :D
 
You are missing the two extra MTMs playing simultaneously aimed towards the front room corners. The walls be highly reflective as a design feature.
That design feature is not a good excuse for unnecessarily chaotic polar patterns if you ask me, but okay.

Instead, put two inherently lobeless speakers in a conventional stereo triangle playing a same signal and repeat your walk. You will understand why these threads exists. Read my signature :D
You mean like my big waveguide speakers? The frequency response and stereo image stay pretty much the same as you walk across the room ;).

I think he's refering to the reflecting firing panels. Not the front one.
But, how many mtm's have the opposing drivers within 1 wavelength?
I guess you must mean w-to-t, right, because this would be somewhere around 2k wavelength w-t? 1 wavelength w-to-t isn't unusual (that's actually the D'Appolito spec., isn't it?). Bah who cares, just measure it and see what you get.
 
That design feature is not a good excuse for unnecessarily chaotic polar patterns if you ask me, but okay.


You mean like my big waveguide speakers? The frequency response and stereo image stay pretty much the same as you walk across the room ;).


Are you saying you cannot hear stereophonic comb filtering ? Double wow :eek:
I believe some people may be immune to it by birth.

This thread is partly about how to circumvent that problem, presenting again another unconventional solution.
 
I'm not trying to say comb filtering from delay is inaudible. Are you trying to say this is somehow eliminated by speakers like your SSS project? I don't see how.

Traditional stereo's delay is a problem of the HRTF.
These types of systems solve the head shadow and pina cues for a central image but.....
They trade this for a more diffused and "comb filtered" R & L image.
I much prefer a solid center image because that's where most of the source is.
 
Well people, I have to take a break from this project.......
I've been commissioned to design and build some omnidirectional speakers for a restaurant in D.C.
it's an awesome concept for a restaurant.

A restaurant, lounge and a downstairs venue for listening parties for audiophiles.

I'll be posting a build thread of course.
Starting on it in a few days.

ps.
I just bought a lathe!
 
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