Polar Response of OB with different length side wings

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ooheadsoo

Re: Polar Response of OB with different length side wings
« Reply #20 on: 10 Oct 2020, 06:10 pm »
I can't see them either. It would be nice to see the full range of responses through 180 degrees to really see how the wings effect the dispersion.

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #21 on: 10 Oct 2020, 06:19 pm »
Only up to 40 degrees? I've done some simulations with a similar approach and the nulls look promising, it's a bit of a mess to the rear but I don't think that should matter too much.

mlundy57

Re: Polar Response of OB with different length side wings
« Reply #22 on: 10 Oct 2020, 06:41 pm »
At 90 degrees there are nulls. This allows the speakers to be placed close to a side wall

guest101973

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Re: Polar Response of OB with different length side wings
« Reply #23 on: 10 Oct 2020, 08:32 pm »
Well, OB speakers are a hard sell in general.  And let's face it, the wings look weird.  Way more weird than the flat panel a traditional OB uses.  And thus have a lower WAF.  And as a manufacturer, WAF is important because you want people to actually buy your speakers. 

But from a pure performance standpoint, a speaker with a narrow baffle will out-image a speaker with a wide baffle, due to differences in edge diffraction.

So the trade-off appears to be that an OB speaker with a narrow baffle will image better, but with a wide baffle it will produce stronger bass.  Is that the main reason to choose one baffle width over another?

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #24 on: 10 Oct 2020, 09:18 pm »
The Linkwitz Lab page I linked to earlier should answer that question, it's well worth reading if you haven't already. Edge diffraction can be mitigated on a large baffle by rounding the edge but means a reduced null but over a larger area.

Tyson

Re: Polar Response of OB with different length side wings
« Reply #25 on: 10 Oct 2020, 10:17 pm »
So the trade-off appears to be that an OB speaker with a narrow baffle will image better, but with a wide baffle it will produce stronger bass.  Is that the main reason to choose one baffle width over another?

Correct, a narrow baffle baffle with no wing will image better than a wide baffle but it will have less bass. 

But, if you add wings to the narrow baffle, it will NOT lose bass and will still have better imaging.

lowtech

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Re: Polar Response of OB with different length side wings
« Reply #26 on: 11 Oct 2020, 06:17 am »
Regarding measurements, perhaps someone can post a -90 to +90 degree measurement to visualize how the "L" frame baffle affects the polar response. Never seen any provided by the manufacturer - maybe just an oversight that can easily be rectified.

mlundy57

Re: Polar Response of OB with different length side wings
« Reply #27 on: 11 Oct 2020, 04:35 pm »
Regarding measurements, perhaps someone can post a -90 to +90 degree measurement to visualize how the "L" frame baffle affects the polar response. Never seen any provided by the manufacturer - maybe just an oversight that can easily be rectified.

Maybe I'm dense, but what type of useful information would a graph from 40 to 90 degrees provide? It seems that even at 40 degrees off-axis you will mainly only be hearing one speaker and, unless you're in an extremely large room, will be up against a sidewall. Curious minds want to know.

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #28 on: 11 Oct 2020, 04:48 pm »
It would show the depth and spread of the nulls

mlundy57

Re: Polar Response of OB with different length side wings
« Reply #29 on: 11 Oct 2020, 05:07 pm »
It would show the depth and spread of the nulls

So what you are trying to do is visualize the figure 8 pattern?

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #30 on: 11 Oct 2020, 05:24 pm »
Exactly

ooheadsoo

Re: Polar Response of OB with different length side wings
« Reply #31 on: 11 Oct 2020, 05:26 pm »
The ear hears an average of direct and reflected sounds, and the reflected sounds are primarily characterized by the off axis response. Dipole cancellation also reduces the audibility of some early refections, so it'd be nice to see how far down in level and in what frequency range the cancellation covers.

The figure 8 pattern is theoretical, real world implementations will vary.

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #32 on: 11 Oct 2020, 06:22 pm »

The figure 8 pattern is theoretical, real world implementations will vary.
Yes, as I say, I've done sims but in reality there are many variables, that's why I'd like to see actual measurements, there aren't many of these speakers about and it's an interesting idea.

Endo2112

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Re: Polar Response of OB with different length side wings
« Reply #33 on: 12 Oct 2020, 04:53 am »
Are you looking to buy a set Scott?? Would you like some referrals?

Don

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #34 on: 12 Oct 2020, 08:17 am »
That would be useful.

mlundy57


Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #36 on: 13 Oct 2020, 07:13 am »
Thanks for those. However there's no measurements of the off axis nulls which are also important with an OB speaker, it's not just about the on axis response.

Danny Richie

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Re: Polar Response of OB with different length side wings
« Reply #37 on: 13 Oct 2020, 01:44 pm »
There may be some misconceptions here, but there are some good questions too.

Instead of just answering the questions I will take some measurements for you guys to help better explain. So I will get back to you guys on this as soon as I get caught up on orders, special projects, and emails.

And then I'll set something up and take measurements. But it will be limited to ranges above 200Hz. Unless I try to move my entire measuring system outdoors. Ugh.

So hang on.

Scott Joplin

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Re: Polar Response of OB with different length side wings
« Reply #38 on: 13 Oct 2020, 03:32 pm »
Above 200Hz would be very informative, thanks.