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Multi-Way Conventional loudspeakers with crossovers

Hybrid H-Frame, OB and nude driver
Hybrid H-Frame, OB and nude driver
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Old 21st January 2021, 05:02 PM   #31
iamvalheru is offline iamvalheru  Canada
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Great suggestion guys, thank you for the time and data.

Between 1x 22W/4534 (TM) and 2x 830668 (MTM), which do you think would provide the best sound quality since cost wise they are pretty much the same.

Are there any advantages of going MTM?


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Old 21st January 2021, 05:04 PM   #32
diypole is offline diypole  United States
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Yes, the dipole peak is dealt with in the 1000hz crossover.

It is also tamed with a baffle, the nude response is the worst case scenario.
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Old 21st January 2021, 05:07 PM   #33
iamvalheru is offline iamvalheru  Canada
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@diypole

How did you come up with those SPL values for the different drivers?

I'm simulating these right now with Basta and the numbers I get are not even close!?!
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Old 21st January 2021, 05:10 PM   #34
CharlieLaub is online now CharlieLaub  United States
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Originally Posted by diypole View Post
Yes, the dipole peak is dealt with in the 1000hz crossover.

It is also tamed with a baffle, the nude response is the worst case scenario.
How large/wide of a baffle did you use for the 10F? I would be interested in seeing measurements of how that influenced the FR on and off axis. I imagine the peak broadens and the peak frequency decreases. That would make a 1kHz crossover much easier. Can you share data on that?
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Old 21st January 2021, 05:18 PM   #35
diypole is offline diypole  United States
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Page index

Halfway down this page, you will see spl_max1.xls

For effective path distance D, use the center of the driver to the edge on one side.

X-max is one way, not P-P.

Add 6db for radiation into half space. You will likely not consider this. It gives results for closed box.

Add 6db at the crossover point to the woofer or subwoofer.

When you get below 80hz you should start to consider the response from the other speaker also, as the signal will be coming from both of them.
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Old 21st January 2021, 05:23 PM   #36
scottjoplin is offline scottjoplin  Wales
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Originally Posted by Pano View Post
Having built and heard quite a few Open Baffle speakers over the past 15 years, it looks to me like you are really making this much more complicated than it needs to be. Of course, overly complicated and edgy might be your goals.

I think it time for me to take my leave, as my advise will have little effect on this project.
There is a difference between dipole and open baffle, how much it actually matters is rarely discussed.
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Old 21st January 2021, 05:24 PM   #37
iamvalheru is offline iamvalheru  Canada
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I simulated a MTM using the 830668 and the 10F/4424G00.

The baffle is W8" x H20".

No crossover applied.

The microphone is set 4m away and offset to get 30 degrees off axis.


I'm trying to attach the screenshot of Basta, but I can't load directly from my PC.
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Old 21st January 2021, 05:26 PM   #38
iamvalheru is offline iamvalheru  Canada
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Attachment.
Attached Images
File Type: png MTM_830668 - 10F.PNG (163.5 KB, 126 views)
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Old 21st January 2021, 05:36 PM   #39
diypole is offline diypole  United States
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Originally Posted by CharlieLaub View Post
How large/wide of a baffle did you use for the 10F? I would be interested in seeing measurements of how that influenced the FR on and off axis. I imagine the peak broadens and the peak frequency decreases. That would make a 1kHz crossover much easier. Can you share data on that?
Hello Charlie, I can dig that out for you when I get home. The best I can do is direct you to the open baffle gallery for now, about 3 or 4 pages from the end I posted the speaker and the measurement.

Have to give credit to John K for figuring out the magic of the 8" to 4" minimal baffle. The 8" is run below the null and peak, and with a crossover at around 1000hz, the peak of the 4" can be dealt with in the crossover. Linkwitz did not want to go 4 way, but after he experimented with it he came to the same conclusion.

I use hardly any baffle...not even a half inch on top, but squared a bit, and expanding below to the 8". Worst case scenario is that the sound is reaching all edges at the same time, as I'm sure you already know. Change it a tiny bit and you reduce the ripple, same as regular diffraction in a closed box.

I still maintain symmetry in the horizontal plane. It does flatten and broaden the peak a bit, and it's close enough to the crossover point that you simply address it with the crossover.
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Old 21st January 2021, 05:40 PM   #40
diypole is offline diypole  United States
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Originally Posted by iamvalheru View Post
Attachment.
Hello iamvalheru. I am talking about absolute spl capability based on Sd, x-max and baffle size.

You do realize you will be using a shelving filter to flatten the response down the crossover point, correct?

Just trying to gauge where you are at.
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