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Old 1st September 2011, 10:31 PM   #21
boris81 is offline boris81  United States
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Quote:
Originally Posted by Rudolf View Post
Not really. These polar diagram simulations show (from left to right) a closed box, an open baffle and a Ripole.
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I don't think this design functions like a ripole. The idea is that the slot amplifies the front wave only. I expect something similar to cardioid behavior.
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Old 1st September 2011, 10:32 PM   #22
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I thought that came out nice. Thanks to Steve for putting it up quickly -
I love instant gratification.

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Old 1st September 2011, 10:39 PM   #23
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Merged 2 threads on the same topic. If you have only been following one you might want to go back and read the posts you missed.

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Old 1st September 2011, 11:11 PM   #24
Rudolf is offline Rudolf  Germany
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Quote:
Originally Posted by boris81 View Post
I don't think this design functions like a ripole. The idea is that the slot amplifies the front wave only. I expect something similar to cardioid behavior.
The AMT-3 has a slot ratio of about 3 to 1 in the front. This is rather conservative. Some ripoles have up to 5 to 1 in order to get lowest bass. A ratio of 1.5 or 1 to 1 in the back is common for ripoles too. In simulations (or built ripoles) you hardly see any more change when going below 1.5 to 1. The air space between cone and back slot simply is too large to allow for that. The 9 dB front-to-back difference stated in the article doesn't really qualify as a cardioid pattern IMHO.

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Old 1st September 2011, 11:46 PM   #25
Tea-Bag is offline Tea-Bag  United States
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Did it mention what woofer driver was used? I didn't catch it.
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Old 2nd September 2011, 01:48 AM   #26
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slot loading like this would still work even if the rear was a normal BR box???
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Old 2nd September 2011, 02:19 AM   #27
CLS is offline CLS  Taiwan
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That would tend to be a band pass.
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Old 2nd September 2011, 02:24 AM   #28
Pano is offline Pano  United States
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Does anyone remember a woofer project from about 5 years ago that was slot loaded with 2 woofers facing each other? The guy put it behind his sofa to get strong bass but not disturb the neighbors. I can't find the tread.
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Old 2nd September 2011, 02:41 AM   #29
boris81 is offline boris81  United States
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Quote:
Originally Posted by Rudolf View Post
The AMT-3 has a slot ratio of about 3 to 1 in the front. This is rather conservative. Some ripoles have up to 5 to 1 in order to get lowest bass. A ratio of 1.5 or 1 to 1 in the back is common for ripoles too. In simulations (or built ripoles) you hardly see any more change when going below 1.5 to 1. The air space between cone and back slot simply is too large to allow for that. The 9 dB front-to-back difference stated in the article doesn't really qualify as a cardioid pattern IMHO.

Rudolf
Hypercardioid?

The slot ratio is one thing and then there is the polarity of the drivers. I might be wrong but I was under the impression that a ripole configuration implies both drivers move together in phase. Here they are reversed. I'm not quite sure what effect that will have on the radiation pattern.

A polar graph will be very informative. This is a very interesting design, I'm also curious to see if the sides can be curved without losing much of the 1:3 output ratio.
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Old 2nd September 2011, 02:54 AM   #30
winslow is offline winslow  United States
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Neighbor friendly dipole sub

I was just looking at it.


Quote:
Originally Posted by Pano View Post
Does anyone remember a woofer project from about 5 years ago that was slot loaded with 2 woofers facing each other? The guy put it behind his sofa to get strong bass but not disturb the neighbors. I can't find the tread.
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