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Old 17th December 2008, 01:23 AM   #931
Patrick Bateman is offline Patrick Bateman  United States
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Quote:
Originally posted by kuribo
Thank you for the reply...

Are the 15 inch speakers more than just a larger version? I was under the assumption that they were just scaled up and that a larger box would take care of any shipping issues....I must be wrong....

Thank you....
I purchase the 15" versions, and I don't see a huge advantage over the 12" version. In fact I would have purchased the 12in version if they were available at the time. I was just too impatient to wait.

They're DEFINITELY more cost-effective.
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Old 18th December 2008, 09:45 PM   #932
pjpoes is offline pjpoes  United States
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As Dr. Geddes mentioned earlier though, the larger waveguide does have the advantage of better directivity control to a lower frequency. This is an advantage over the smaller versions. If you are crossing over too high, say above 1khz, then I could see you not feeling there is an advantage, but otherwise, I don't really understand how you don't see the advantage of a larger waveguide. I can't speak to the HOM supression, thats Dr. Geddes deal, as I have no experience, but the better pattern control over a broader range is the most fundamentally understood part of changing a waveguides size. While I haven't seen measurements of the 12" and 15" versions to know this, I would estimate that there must be atleast a 200hz lowering in pattern control, say down to 800hz, with much better control at 1khz.
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Old 18th December 2008, 11:49 PM   #933
gedlee is offline gedlee  United States
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I think that what Patrick is saying is not that the 15" waveguide wouldn't work better, its just that the Abbey is a much more palatable choice than the full 15" Summa. From my limited experince of direct listening I would say that is true. The 15" does sound better, but the Abbey is very close and the size and cost difference is substantial.

I'm still looking for that "sweet spot" of the design, maybe a 12" woofer and 15" waveguide, maybe a 12" woofer and a 15" x 10" elliptical, I don't have enough data yet to know. But of the data I have the Abbey is the clear leader in terms of best compromise.
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Old 19th December 2008, 01:13 AM   #934
pjpoes is offline pjpoes  United States
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Well that makes sense, ok. I thought he was saying that the 15" isn't any better than the 12" in terms of capability, which I didn't understand.
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Old 19th December 2008, 04:35 PM   #935
Patrick Bateman is offline Patrick Bateman  United States
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Quote:
Originally posted by pjpoes
Well that makes sense, ok. I thought he was saying that the 15" isn't any better than the 12" in terms of capability, which I didn't understand.
Yeah, I should have clarified that. Law of diminishing returns is in full effect with the big Summas - the expense of the larger unit may not justify the incremental improvement in performance.

Just for fun I'm building another Unity, should be interesting to see if the bigger waveguide makes any audible difference. Originally I was going to make it 28" across, but settled for 24". It's still B-I-G.

It will be a while before it's done.


Click the image to open in full size.

Another Unity Horn
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Old 19th December 2008, 06:43 PM   #936
gedlee is offline gedlee  United States
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Whats the Great Stuff for? While I like that brand in some situations, for bulk filling its very expensive. Go to US composites and order the polyurethane in bulk, its much cheaper and the bulk is easier to deal with if use to fill large spaces.
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Old 19th December 2008, 07:59 PM   #937
MartinQ is offline MartinQ  Canada
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I want to know what the green stuff is. Is this the famed chilly-lime horn?
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Old 19th December 2008, 08:07 PM   #938
Cal Weldon is offline Cal Weldon  Canada
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DIY Waveguide loudspeaker kit
Jones green apple soda is my guess.
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Old 19th December 2008, 08:16 PM   #939
Patrick Bateman is offline Patrick Bateman  United States
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Quote:
Originally posted by Cal Weldon
Jones green apple soda is my guess.

How on EARTH did you guess that?

That's exactly what it is!
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Old 19th December 2008, 08:27 PM   #940
goskers is offline goskers  United States
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There are very few green drinks on the market. It was definitely a good guess. After this it was either Kool-Aid or Absynthe.
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