Chris Roger's DIY Transmission Lines

[saschagabor]

That was a nice build thread, but after skimming through I didn't see any reference to TL with A26RE4.

The one I'm thinking about is the "Classic TL
a modern rendition of the classic Radford/IMF TL for World Design WD25A speaker kit".

[Richard]

Hi, Never seen anyone mention it here, has that speaker been built or is it just a simulation? I guess that thread was offered as related reading.

[david counter]

Originally Posted by Richard

t I guess that thread was offered as related reading.

exactly Richard

[saschagabor]

It's mentioned (my previous quotation) and commented by petercom on this page:

http://www.world-designs.co.uk/forum...?t=2810&page=5

I've seen it built by a guy with lots of cats, I'll se if I can find the link again.

[saschagabor]

Originally Posted by david counter

exactly Richard

I'm sorry if I sounded ungratefull, that was not my intention. I did however feel that I had to specify what I was after.

[Richard]

Originally Posted by saschagabor

That was a nice build thread, but after skimming through I didn't see any reference to TL with A26RE4.

The one I'm thinking about is the "Classic TL
a modern rendition of the classic Radford/IMF TL for World Design WD25A speaker kit".

Hi, I don't see Petercom mentioning the design you refer to if it's this post,

"Just to put an end to the speculation...

As you know I do like Aperiodic systems, I always have since hearing the original ScanDyna A25 and Celef Professional Monitor speakers back in the '70s.

Bailey's original work was for a 'Non Resonant Speaker' describing an Aperiodic line that used stuffing to absorb both the back pressure from the drive unit and the harmonic resonances in the line. Only in the second paper published in Wireless World did this become a 'Transmission Line' speaker.

Whatever you call it the Bailey speaker is an attempt at an Aperiodic design using an absorptive, damped line. To my mind most commercial interpretations of this have erred towards bass-reflex operation using a lining to the walls of the line to help quell the harmonic resonances.

Now you might think I'm splitting hairs but, as Richard points out, the trouser-flapping bass that comes from designs such as the IMFs just seem to provide over-endowed 'whoomph' with little bass articulation. This wasn't Bailey's aim and neither will it be mine in the design of the Radford TLs.

SEAS A26RE4 is, of course, optimised for an Aperiodic enclosure and we've got it to work happily in both a stand-mount, with external vent, and a floorstander, with internal vent. It should, therefore, also suit a TL.

However a unit as large as A26RE4 requires a very large cabinet as a TL, largely because of the volume of the enclosure needed behind the driver itself before you even start on the line! This will probably make it a non-viable commercial proposition for Radford (enormous speakers don't sell all that well in shops) so a 21cm driver is probably the largest we'll consider.

That doesn't mean that we can't move on to a huge TL for a World Designs project based around the A26RE4 - that I'll have to decide when the time comes! "

[saschagabor]

I feel he did, though only indirectly, to clarify his own intentions. He states that the driver is suitable for TL, but that the cabinet needs to be too big for anything he would consider for a commercial product.

With an interlal volume of about 150 liters, he's probably right about that. However, it's not something I'd consider as too large, but I would probably get a few grunts from the missus.

[Richard]

Hi, maybe, but I think the design you linked to is not connected with Peter other than use of those drivers, perhaps I'm wrong, can anyone shed light on that design, there were a few simulations around then iirc?

[A Stuart]

Sorry, this post added nothing so deleted.

[saschagabor]

I found what I was looking for:

http://www.world-designs.co.uk/forum...ead.php?t=4769