Anybody wanting to simulate or build a 4- or 5-way dipole speaker?

[454Casull]

Have at it.

[454Casull]

There must be some interest?

A 3-way sheet is possible as well, but many compromises need to be made to get decent SPL.

[auplater]

Originally Posted by 454Casull

There must be some interest?

A 3-way sheet is possible as well, but many compromises need to be made to get decent SPL.

Don't know about that. I built an RD-75 Dipole as a marginally 3 way back in '05 with exceptional results... but then that's an actual design with an exceptional driver...

John L.

[454Casull]

Originally Posted by auplater

Don't know about that. I built an RD-75 Dipole as a marginally 3 way back in '05 with exceptional results... but then that's an actual design with an exceptional driver...

John L.

Long ribbons certainly were not a consideration... In terms of volume displacement, power handling, and horizontal directivity, they are excellent - but vertical directivity is compromised. Perhaps for a long driver that isn't a bad thing.

Did you experience any floor bounce effects?

[boris81]

Originally Posted by 454Casull

There must be some interest?

It says 22 views
Good job, I like it. I will probably use at some point.

I am not very clear on how to calculate the frequency where the dipole starts to bring down the low end response. Can you please explain how it's calculated?

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As for recommendations I will suggest making some interactive graphs even if they are pretty simple. There's no substitute for being able to see instantly how changing one parameter affects the rest of the system.

[454Casull]

Originally Posted by boris81

It says 22 views
Good job, I like it. I will probably use at some point.

I am not very clear on how to calculate the frequency where the dipole starts to bring down the low end response. Can you please explain how it's calculated?

--
As for recommendations I will suggest making some interactive graphs even if they are pretty simple. There's no substitute for being able to see instantly how changing one parameter affects the rest of the system.

It's been a long time since I adapted the equations to fit the sheet, but if you set the high-pass high enough such that a driver shows a dipole loss of 0 dB, there is no loss in sensitivity or max SPL whatsoever. The caveat is that the driver is probably either running a very small pass-band (not so much a problem in a 5-way) or the passband has gone over the dipole peak. At this point, there are a few things you can do: 1) reduce the size of the baffle, if a baffle is used, or 2) if the driver is running naked, select a smaller driver.

The low end only starts to suffer as dipole loss increases - and Tolvan's Edge should be used to verify how bad the effects are.

If you are asking how the equations are derived, I cannot explain. The equations are taken from Mr. Linkwitz's work.

[auplater]

Originally Posted by 454Casull

Long ribbons certainly were not a consideration... In terms of volume displacement, power handling, and horizontal directivity, they are excellent - but vertical directivity is compromised. Perhaps for a long driver that isn't a bad thing.

Did you experience any floor bounce effects?

here's the 0,15,30,45, and 60 degree off axis curves from 5 years ago, off set vertically green red purple blue and orange respectively, meassured 15 feet back in a ~15,000 ft^3 room

How to Tell How a Speaker Sounds in a Room: (Supplement to REG's review of the McIntosh XRT28s)



vertical directivity "compromise" I see as a plus in 6' tall speakers... mid-woofers are down low, so no floor bounce to speak of...

John L.

[454Casull]

Originally Posted by auplater

here's the 0,15,30,45, and 60 degree off axis curves from 5 years ago, off set vertically green red purple blue and orange respectively, meassured 15 feet back in a ~15,000 ft^3 room

How to Tell How a Speaker Sounds in a Room: (Supplement to REG's review of the McIntosh XRT28s)



vertical directivity "compromise" I see as a plus in 6' tall speakers... mid-woofers are down low, so no floor bounce to speak of...

John L.

These are horizontal off-axis curves? What about the vertical?

And I was wondering about floor bounce from within the same driver - i.e. from top to bottom, is there any destructive interference?

[auplater]

Originally Posted by 454Casull

These are horizontal off-axis curves? What about the vertical?

Didn't measure much more than cursory... within the horizontal 6' spread, not much variation as well... that was a major purpose of the design

Originally Posted by 454Casull

And I was wondering about floor bounce from within the same driver - i.e. from top to bottom, is there any destructive interference?

no

[454Casull]

Updated