# TDL Transmission line speakers



## steam3642

Hi
 I am looking to buy a second hand pair of Tdl moniter loudspeakers but they are very large , thought i might look for some other owners experience
 before i hire a truck to bring them home for a test ( maby not a truck but gee there large) anyone have some experience with these and are they a worthy match for a M/Fidelity A3cr Pre/Power 120wpc. thanks.


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## rickcr42

Wellno first hand experience i but i do remember the reviews when they came out and all were raves in favor of the speakers.The bass is supposed to hit 27hz and that is a note very few subwoofers can even contemplate plus the accuracy was top rated.From memory the only area that did not rate with the absolute best was the stereo image and depth and that was compared to the Dahlquist DQ-10 a known great imaging loudspeaker and the magnepan which is a planar/bipolar speaker.also superior in that area.

 from the transmission line website







 more TDL info here-

http://www.t-linespeakers.org/TLS80/index.html

 and here-

http://www.t-linespeakers.org/classics/TDL.html

 I.M.Fried who designed the TDL line also designed the IMF speakers and Fried lines.And was a champion of the TL technology.

http://www.t-linespeakers.org/classics/TLS80/index.html



http://imf-electronics.com/

 hopefully helpful information

 Rick


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## steam3642

Thanks Rick
 i am using Spendor bc1 at the moment , thought a pair of TDLs
 would take the sound up afew notches. thanks


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## rickcr42

Quote:


 Spendor bc1 
 

ahh,that it explains much.What you can expect is more of the same basic sound due to the drivers being mostly identical but the dynamics and volume levels will be as you put it "more' .Kinda a BC-1 with muscle.

 enjoy man

 rick


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## steam3642

Thats true i love the sound of the Bc1 , if Tdl Monitor is like Bc1 on steroids 
	

	
	
		
		

		
		
	


	




 i will be laughing . Thanks.


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## rickcr42

couple of things-

 I moved this to the correct forum.

 second-memory is funny in that it comes back in spurts so i just want to add another tid bit from my memory files.The TDL studio monitor was also considered "deadly" accurate.By that I mean at times it could be merciless in the reproduction at the top end.The addition of a 1/2 inch dome "supertweeter" was the reason and it was noted in a couple of reviews that this was a good thing if absolute accuracy was a concern but with some recordings it would reveal any top end imperfections and that is not for everyone.
 So i guess it also differs from the BC-1 in some of the "romantic" vs "accuracy" areas.
 I also "seem" to remember and this could either be my own observation at the time or maybe i read this,i really do not know,that if this became a problem the easy fix would be to remove the supertweeter and run the tweeter full range.
 and again,if memory serves all the drivers were KEF _except _ for the ST which was a coles.

 hope this "addy" helps a bit in your decision 

 rick


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## steam3642

Thanks for all your help its great , your right they are Kef and coles s/tweeter
 I found this out when i aked the dealer as i was concerned about spare parts as the company is now closed, $1200 aus is the asking price , how does that sound ?


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## rickcr42

well i am one of those people who notices the _lack_ of equipment being offered on the second hand market and since there obviously were a lot of these made but they rarely turn up for sale it is my guess that the folks who have them are satisfied and not letting theirs go.A normally good sign.

 As to value,that is always up to the individual and what that person is willing to pay for something they either want or need.I really do not know the answer.
 but nice speakers they are and every driver is a "known" quantity with the specs available on the net.Plus it would not surprise me at all if there were a market somewhere providing replacement drivers.not "knockoffs" but the actual original drivers which were the basic building blocks behind many Brit designs of the era.
 All highly touted designs i might add,including your BC-1s.

 No.usually the "classic" designs retain value and even if you were dissatisfied i think re-selling them would not be a problem .

 just my personal opinion though guy.

 Rick


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## r3cc0s

My dad had a set of IMF mark IV and they were just phenominal speakers
 used the kef I think 9 x 12? I think oval flat dome, which was laminated for extra ridigity
 Used a BBC super tweeter
 not sure what the 4" was

 but it was a phenominal sounding speaker
 deep and relatively flat and british sounding speaker, alot of detail
 analitical

 it's great


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## rickcr42

Quote:


 used the kef I think 9 x 12? 
 

that would be the B-139 a phenominal and legendary speaker .I can still remember (damn i guess i am getting old man) the literature and reports on this driver and how it was touted as a prefect piston because there was ,i think,a foam filler inside and the front being dead flat actted to push air uniformly with no time based errors.
 Way easier to make a phase coherent system when the woofer cone does not start eight inches behind the mid and tweeter cones/domes.

 Yeah,i must be aging fast when he remebers things out of production for twenty years as if it were yesterday.Next thing i know i will be telling my kids i walked to school when i was a youngster in 25 feet of snow ten miles up hill


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## rickcr42

heh,even better man :

http://www.t-linespeakers.org/drivers/b139.html

http://homepage.mac.com/tlinespeaker.../B139small.GIF


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## r3cc0s

From what I can tell, these transmission lines the RF mark IV seemed even better than anything I have ever heard from my dad's setup
 He's tried a few vandersteens, vienna accoustics, martin logans and b&w's (being rather vague here)
 but just saying
 they were probably the biggest speakers, but definately was the most transparent, maybe the most detailed (even comapred to Monitor audio Gr20) and definately the deepest bass I've ever heard/felt

 I'm wondering why transmission line is no longer implemented, or rather is it just due to a manufactoring cost? (my dad said they were hand made and are rather expensive I belive he said the cost was $7200 back in 1978)


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## rickcr42

Quote:


 I'm wondering why transmission line is no longer implemented, or rather is it just due to a manufactoring cost? 
 

I would say yes.The actual internal build is extremely complex and the damping material filler which is tuned by ear is extremely labor intensive.why go to all that trouble when you can software model a "box" and put the drivers in.Other than some od the horn work most speakers today are just a variation of the other and mostly use the same drivers in the same box witha different "face"

 the transmission line is trial and error ebven after it is modelled and is not for the labor ot time squeemish.Maybe that is whu other than some clasic low power DIY Brit designs and the I.M. Fried designs the TL has been not seen

 I.M. Fried=
 IMF
 Fried Products
 TDL

 And any DIY or technology articles on the TL in the audio press .He championed the TL when other stook another path and without his presence it has slipped into the "used equipment" or "DIY" category mostly.


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## sethk

There are a few other companies making transmission line speakers (not the same exact design as the speakers you mention) but it's questionable if they are "true" transmission lines or even what construes a true transmission line.
 Some of the Vandersteen speakers come to mind, along with Meadowlark.

 Here's a good thread on the subject at audiogon (don't know if the link will work if not go the discussion forum and search for transmission should be one of the top hits "Who makes a "true" Transmission Line speaker?"):
http://forum.audiogon.com/cgi-bin/fr...zztransmission


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## rickcr42

there is a Fried full range system that I beleive predates the Vandersteen but has an uncanny resemblance .Basicaly a mini-monitor attached to a subwoofer bottom but the cutaway view looks the the vandersteen .Kinda the chicken or the egg scenario.Which came first and who should get the kudos (goes back to who was first with phase coherent-Vandersteen or Dahlquist)

http://imf-electronics.com/documents...oudspeaker.pdf



 The "true" TL loudspeaker system has a series of resistive paths that tuned by bothear and equipment determine the bass F3.From the above cutaway you can see just how complex the series restance and angles can be.That is why the TL is such an expensive beast but for true low bass it is not bettered.It just is not the most POWERFUL bass when playing rock at high spl levels.No other bass tuning method gets so low with such a flat line frequency response 

http://imf-electronics.com/documents...subwoofers.pdf


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## pbirkett

Quote:


  Originally Posted by *r3cc0s* 
_I'm wondering why transmission line is no longer implemented, or rather is it just due to a manufactoring cost? (my dad said they were hand made and are rather expensive I belive he said the cost was $7200 back in 1978)_

 

Rega still make relatively inexpensive transmission lines speakers in the form of the Ela's, of which I own a pair and they are an excellent pair of speakers - I've never heard such speed from a pair of floorstanders as they've got and the mids and trebles is very sweet.

 A company called Meadowlark did/does make transmission lines still and they too sound good, with big powerful bass


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## marios_mar

Quote:


  Originally Posted by *steam3642* 
_Hi
 I am looking to buy a second hand pair of Tdl moniter loudspeakers but they are very large , thought i might look for some other owners experience
 before i hire a truck to bring them home for a test ( maby not a truck but gee there large) anyone have some experience with these and are they a worthy match for a M/Fidelity A3cr Pre/Power 120wpc. thanks._

 


 A friend of mine has these speakers driven by a creek amp. He had those well matched with a M-Fidelity before the Creek. He switched amp because it got stolen.

 I have heard those speakers a few times. They sound nice but I havent heard the BC1s to compare. The bass is not really good though. At least compared to what I am used to with headphones. Kind of dark and muddy. But maybe it was the placement and room that played a role. 

 The treble has nice energy to it and I like that. Vocals and midrange was also pleasing and smooth. I think that more experimenting with placement could bring out better results than what I heard. Interesting ones... How much are you getting them for though? 

 Have you though of some modern pair of 602 s3s by B&W?


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## steam3642

I am looking at a pair of B&W DM 620i , from around 1998 , update : they were on e.bay but decided against them.


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## steam3642

Quote:


  Originally Posted by *marios_mar* 
_A friend of mine has these speakers driven by a creek amp. He had those well matched with a M-Fidelity before the Creek. He switched amp because it got stolen.

 I have heard those speakers a few times. They sound nice but I havent heard the BC1s to compare. The bass is not really good though. At least compared to what I am used to with headphones. Kind of dark and muddy. But maybe it was the placement and room that played a role. 

 The treble has nice energy to it and I like that. Vocals and midrange was also pleasing and smooth. I think that more experimenting with placement could bring out better results than what I heard. Interesting ones... How much are you getting them for though? 

 Have you though of some modern pair of 602 s3s by B&W?_

 

The dealer is looking at $1200aus , original list was about $7000 aus , but its a consignment sale so it could be neg , if i were to get them i would change the finish to a nice " jarrah colour" an
 Australian hardwood with a deep red texture , they would be a nice hobby as my original trade is in cabanet making , i also listen to vinyl more than cd which to me suits the 70s design speakers better than cd , thats just to my ears though


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## marios_mar

Quote:


  Originally Posted by *steam3642* 
_The dealer is looking at $1200aus , original list was about $7000 aus , but its a consignment sale so it could be neg , if i were to get them i would change the finish to a nice " jarrah colour" an
 Australian hardwood with a deep red texture , they would be a nice hobby as my original trade is in cabanet making , i also listen to vinyl more than cd which to me suits the 70s design speakers better than cd , thats just to my ears though 
	

	
	
		
		

		
		
	


	


_

 

careful...

 TTs of today are not like the ones in the 70s! Modern speakers can show the improvements better i guess..


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## steam3642

Quote:


  Originally Posted by *marios_mar* 
_careful...

 TTs of today are not like the ones in the 70s! Modern speakers can show the improvements better i guess.._

 

 I use a Rega planar 2 with RB250 arm , sounds great but there are much more refined TTs , mabey when the Rega's motor gives up


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## viveksaikia22

Inspired by this thread, I went ahead and made (DIY) a fast prototype of a Transmission Line speakers. Check out the video on Youtube -
   
  http://youtu.be/UKRZYGbXE2Q
   
  Let me know what you think of this build?


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