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Old 8th May 2006, 06:40 PM   #21
Relax is offline Relax  United States
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I think my post was deleted, but I was wondering if anyone has built a TL the same size as a tapped line. Then try the driver in the two positions to see differences?

It would be a rather simple way to see if they are close enough to be modeled the same.
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Old 10th May 2006, 02:01 AM   #22
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While I agree that a tapered divider would seem the obvious choice. I think Danley's version is built similar to this....

Walts Stepped Horn

With the driver located near to the 'step'.

While the current pictures at Danley's site make it difficult/impossible to see. In previous pictures one could see the dividing wall through the port to be straight. In fact early renderings showed the port to 'wrap' around 3 sides of the cabinet. Now reduced to a single port, probably to allow for flush mounting in a wall.

A stepped layout would make bracing far simpler, and more akin to mass production as well.
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Old 11th May 2006, 01:41 AM   #23
qi is offline qi
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Quote:
Originally posted by Relax
I think my post was deleted, but I was wondering if anyone has built a TL the same size as a tapped line. Then try the driver in the two positions to see differences?

It would be a rather simple way to see if they are close enough to be modeled the same.
Hi Relax

Here is an idea for you.

The driver in a standard enclosure on the same end as the port gives you a traditional t-line.

A modified enclosure and on the opposite end gives the "experimental" design.

The end opposite the driver /enclosure would then be capped off.

The unit is 60" x 12" x 12" and is tuned to 17-18hz.

You will need a 50hz 4th order xover for such a low tuning...

Traditional...
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Old 11th May 2006, 01:44 AM   #24
qi is offline qi
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The same 16' tuned pipe with the driver / enclosure on the other end.

The front of the driver fires into the tuned pipe 4' from the sealed end.

The rear of the driver fires into the tuned pipe 4' from the open end.

The end opposite the driver /enclosure is capped off...
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Old 11th May 2006, 01:51 AM   #25
qi is offline qi
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Quote:
Originally posted by Tehrasha
While I agree that a tapered divider would seem the obvious choice. I think Danley's version is built similar to this....

Walts Stepped Horn

With the driver located near to the 'step'.

While the current pictures at Danley's site make it difficult/impossible to see. In previous pictures one could see the dividing wall through the port to be straight. In fact early renderings showed the port to 'wrap' around 3 sides of the cabinet. Now reduced to a single port, probably to allow for flush mounting in a wall.

A stepped layout would make bracing far simpler, and more akin to mass production as well.
Thank you for your feedback.

Yes, I too have looked at all the the posts / pics regarding this subject.

My SKETCHUP is based on all of that information and actual pictures of the unit.

Also, an email specifically mentions that it is tapered.
Quote:

In fact early renderings showed the port to 'wrap' around 3 sides of the cabinet. Now reduced to a single port, probably to allow for flush mounting in a wall
AFAIK, the port exits from the side, or optionally exits from the bottom

Walt's design is "close" (as I am sure you have seen).

Walt mentions he is not "down 3db at 16hz", however (the TOP published specs).

I believe Walt needs to go to a longer pipe and / or smaller port.

Regards...
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Old 11th May 2006, 06:02 AM   #26
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What lead you guys to the conclusion that the pathway is tapered at all. The pic I saw which is no longer available looked to me like a constant size pathway, and that Danley's design is just an offshoot of the 1950's Jensen Transflew. The driver is just in a different location. Wouldn't this make it some type MLTL ?
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Old 11th May 2006, 07:54 AM   #27
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Sorry qi, been a bit busy to reply. Certainly your model feels aesthetically correct with the sloped line, rather than stepped, and I'm sure to improve on the Transflex it has to be significantly different, unless the patent purely applies to the method of calculation. I think it's safe to assume that the driver is in the middle of the enclosure, otherwise why go to the effort of cutting an access hole half way down. Unfortunately, my PC measurement system is inoperative at the moment, otherwise I might build a test cab to experiment with.
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Old 11th May 2006, 11:40 AM   #28
qi is offline qi
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Quote:
Originally posted by johninCR
What lead you guys to the conclusion that the pathway is tapered at all. The pic I saw which is no longer available looked to me like a constant size pathway, and that Danley's design is just an offshoot of the 1950's Jensen Transflew. The driver is just in a different location. Wouldn't this make it some type MLTL ?
That's exactly what I thought, but an email I read specifically mentions that it is tapered.

My original SKETCHUP...
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Old 12th May 2006, 05:34 AM   #29
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I've been trying to decide what to build as a sub for a false stage under my projector screen. I'm thinking that trying this thing with 10hz tuning and 4 segments is the way to go. I have a few 15's to try, all with dual VC's, so I use RDO to adjust the Qts and can even try isobarik if it's too sloppy or it acts like the total air volume is too small. Do you think 4 times the terminus area that Danley uses makes sense to go an octave lower, or is double the distance around his terminus the right number, or neither?

What about bracing? Is it ok to divide pipe pathways in half ?

Any input is greatly appreciated.
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Old 12th May 2006, 11:51 AM   #30
qi is offline qi
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My two cents...

I would model it in MJK as a regular straight t-line

Optimize the model with stuffing as usual

Use those specs

Substitute this new technology for the stuffing (ie., no stuffing)

Center bracing is certainly a way to go (dowels are often used)

Just make sure the total CSA inner dimension is to spec

I personally would tune to 15hz and xover at 40hz

10hz tuning is WAY LOW (as I am sure you know)

With 10hz tuning where would you xover?
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