Transmission Line with B139B

[No Nickname]

Hello!

I am a new member and I hope to get some new ideas for the following question. The idea is to build a TL box with some speakers from an older Kef CS7 (B139B, B110B, T33A).
I investigated a little bit and found 4 possibilities. Has anybody an idea about the strengths and weaknesses of these possibilities?

http://homepage.mac.com/planet10/IMF_TLS80_brochure.pdf
http://homepage.mac.com/planet10/TLS/downloads/Pro9TL-1.pdf
http://homepage.mac.com/planet10/TLS/downloads/Pro9TL-Mk2.pdf
http://www.exdreamnet.de/bauplaene/tml/bailey_tml.jpg


26 years ago I already built the last one (the Bailey) and the result didn’t convince me. However, it could be that the dampening wasn’t perfect. At least I think that this could have had a negative impact.
Of course I am aware that some of these possibilities have other midranges and tweeters. But I want to focus on the bass first and optimize the rest with an active crossover for proper results.

Thanks for any comment🙂

 

[planet10]

You've been to TLS.org. but you missed the best TL for the B139.

same TL, 3 variations on the theme.
Transmission Line Speakers

A buddy built these with really good results:

He did have to shorten them a couple inches to fit into his apartment with 8' ceilings.

dave

 

[No Nickname]

Nice proposal😀 Somewhat big, I will think about it.

Thank's

 

[planet10]

That is for a pair of B139. The singles are really no bigger than a set of IMF refs or the Baileys. The others you mention are really too small to be considered anything but over complex aperiodic boxes.

dave

 

[No Nickname]

Hi Dave,

do you have the still the original plan for the Pro9 TL MKII?
In this plan some information is missing (Fig. 3 and Fig. 10)
Especially Fig. 10 should show some important measurements.

http://homepage.mac.com/planet10/TLS/downloads/Pro9TL-Mk2.pdf

Thank you for any help.

Best regards
Frank

 

[planet10]

Frank,

I never had the original article, only the reprint from Falcon, all of which is in that pdf.

This is not the box i'd build for B139 BTW.

dave

 

[No Nickname]

I havn't decided yet, just tried to compare the length of the different lines.
I don't understand why the bass oft the MKII should be so much better that the MKI. Some user posted that.
I understand that you would prefer the Bailey's - although the B110 is in the open line?

Best regards
Frank

 

[planet10]

I wouldn't build the triangular Baily line (certainly not as is). When i refer to the Bailey line, i refer to the original, upon which the Radfords, IMFs, and TDLs were based.

As to the Pro9TL, my understanding is that the bass was much the same, the big difference due to avialbility of better mid & tweeter.

I myself would not consider any of the classic designs, i'd be much more comfortable going ahead with the one Scott specified using modern modelers.

dave

 

[koozoop]

Good evening,

old thread but is it possible to give us more info on the TL variarion your friend built? What kind of bracing did he implement? Can anyone make this a 3way speaker with a proper crossover?

 

[planet10]

… on the TL variarion …

Of which variation do you speak?

dave

 

[koozoop]

Good evening,

I was reffering to this post:

You've been to TLS.org. but you missed the best TL for the B139.

same TL, 3 variations on the theme.
Transmission Line Speakers

A buddy built these with really good results:

He did have to shorten them a couple inches to fit into his apartment with 8' ceilings.

dave

Thank you

 

[planet10]

What kind of bracing did he implement? Can anyone make this a 3way speaker with a proper crossover?

He built it as drawn.

To make a 3-way one would have to use a smallish midrange, like a 3”, and run a 4” tube out thru the back. Anything larger and you will probably need to graft the 2-way part onto the side.

I’d use a good FR (FF85wKen or Alpair 5.2eN) and forget the tweeter. Crossing low (250-350Hz) you are usually ahead bi-amping.

dave