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TDL Electronics Owners Thread

SimplySound

SimplySound

Kent Engineering & Fondry
Well, I was surprised we didn't have a specific Thread for TDL Speakers. I guess maybe the IMF Owners Thread has served that purpose for all these years. But here we go....

This is the place to acknowledge and talk about all things associated with Transducer Development, Ltd. or TDL Electronics; the culmination of the genius of one John Wright!!!

If you own any of the various Studio's, Compacts or the "Reflex Transmission Line" RTL's feel free to compare notes. Let's leave the Richer Sound TDL's out of this discussion please, as they are a completely different speaker.

Let the banter begin!!! :yes:
 
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In acknowledgement to the role that the supporters and developers of the IMF Electronics Web Site have played in preserving the history of IMF/TDL, I present some of their information on the life and genius of John Wright...

John Wright 1939-1999

Paul Messenger remembers an inventive, resourceful gentleman who had more influence on the British hi-fi industry than many people realised.

John Wright was one of the more important figures on the post-war, British, specialist hi-fi scene. A gentleman through and through, he maintained a relatively low profile in recent years, so it’s all too easy to underestimate the contributions he has made to British hi-fi since the mid-1960s.

In a very real sense John was a ‘bridge’ between the first generation hi-fi companies founded in or before the 1950s, and the new wave that came into being during the 1970s. One of his strengths was an ability to combine the solid engineering traditions of the past with a more open-minded appreciation of the subjectivist approach.

The recent TDL Electronics chapter was just the final phase of a long career, in which John distinguished himself not only as a loudspeaker engineer of some repute, but also took on the roles of inventor, writer, reviewer and businessman - all with considerable success.

During the 1960s he was involved with transducers at the front end of the hi-fi chain. His Audio & Design operation developed a well regarded pickup arm with mercury contacts to avoid lead-out wire torque, as well as the original vacuum record cleaning machine that is still made today under the Keith Monks brand.

The real business breakthrough, however, came around 1970, and at the other end of the hi-fi chain, when John’s large transmission line loudspeaker designs first appeared. Made by TDL with ELAC drivers, and marketed under the IMF Electronics brand, these monitors took advantage of the availability of high power transistor amplifiers to set a new ‘high-end’ benchmark, which helped raise the status and profile of British hi-fi speakers around the world.

Although John will be best remembered for his transmission line loudspeakers, his personal enthusiasm for the whole hi-fi thing led to involvement across a much broader stage. He wrote seminal articles and reviews on loudspeakers for Hi-Fi News and Hi-Fi Sound magazines, reviewed classical music releases for Hi-Fi Answers, and covered phono cartridges and arms for The Gramophone.

In 1980 he left IMF to join the research programme that developed the Ambisonics surround sound system, alongside academics such as Michael Gerzon and Peter Fellgett. Although the consumer world wasn’t ready for yet another surround sound format, the Ambisonics principles and techniques of soundfield encoding are still highly regarded by the professional sector today.

John subsequently returned to the ELAC/TDL operation and, when Harman purchased ELAC in 1989, he organised a management buyout of the TDL brand. TDL Electronics stopped supplying drivers and systems to other manufcturers, and John introduced the Studio line, which updated the transmission line tradition with newly developed metal diaphragm drivers. He then produced the highly successful and more affordable RTL (Reflex Transmission Line) series, which cleverly anticipated the mid-1990s trend towards budget price floorstanders.

That anticipation was typical of John. Even though he viewed modern marketing methods with a certain detached cynicism, one had to admire his ability to keep one jump ahead. I would sometimes ask him a deliberately provocative question and usually received an even more challenging reply, invariably delivered with a twinkle in the eye.

Above all, I'll remember his open-mindedness and readiness-at least-to consider new ideas. Mention some tweak and the chances were he’d already tried it for himself - and he never dismissed even unlikely suggestions out of hand. One of his final acts was to sell TDL to the very experienced Gordon Provan, to ensure the continuity of the brand, the company, and its workforce.


Long live the memory of John Wright!
 
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Amen! John Wright was a hell of a guy. He not only contributed with speakers but also helped make the first vacuum record cleaner (still being sold today).

I no longer own the RTL3s but did for a time. They were pretty nice speakers overall.


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Well, now that I have actually taken delivery of my TDL Studio 4's, I guess I can now speak as an actual owner. These were the follow on to the 4-way Monitor which sat right below the Reference Standard in the Studio Line!

My pair have serial number S4391/154L (and R). I don't know for a fact how many of these were ever made, but I'll venture a guess that the S4391, means that these are a Studio 4 manufactured in March of 1991. And the fact that they are #154 makes me wonder how many more were actually built until TDL Shutdown in 1999(?).

I would assume the Studio 4's were maybe not made to much after this date since they then went to the Studio 1, 0.75 and 0.5 designations. Anyone with any additional information please feel free to post it here. I'd be interested to hear anything anyone has to share.

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Thought I'd post some driver information...

I believe the Bass drivers and the Tweeters were TDL Designed especially for the Studio Series, but built by Elac. The mid's are probably standard Elac units.

Check these out...

Bass Driver Break Away

Tweeter Break Away

My Tweeters are Elac 25DT-57's. Falcon Acoustic lists the 25DT-56 for the Studio-4's, so the 57 may be an evolution.
 
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SimplySound what is the area of the line terminus vent of the TDL?

It appears that there are 2 pieces of foam used in the last fold of the T-line by the photos.
I am looking for any similarities of the TDL stuffing density, taper ratio and line length compared to the IMF and Fried Products T-lines.
 
sm19422 said:
SimplySound what is the area of the line terminus vent of the TDL?
Click to expand...

The terminus ports are 4"WX4 3/8"H and there is 7/8" between them.

If I get inside of these one day, I'll come back here and post any info I have on the actual line.
 
SimplySound said:
The terminus ports are 4"WX4 3/8"H and there is 7/8" between them.
.
Click to expand...

I assume the TDL woofer has the same cone area as the Kef B139 which is 354 cm squared, 55 square inches.
The vent opening is approximately 35 square inches on your TDL T -line.
I.M. Fried used a 36 square inch vent opening on his O4 sub T-lines that use a 10" driver which has about the same cone area as the TDL woofer.

I have always thought that Wright and Fried used the same design parameters in their T-line designs.
 
Im on the verge of buying a pair of TDL speakers. They are not all original (drivers are, enclosure - and perhaps stuffing is not), I would therefore greatly appreciate it if someone owning a pair of Reference Standard/Monitor/Studio 4/3 speakers could tell how the line in their speakers is damped. These have egg crate foam visible in the end of the line, but the non-visible part of the line is damped with a material that feels more like rockwool? I would expect the original speakers to have egg crate foam higher in the line too? Thanks.

(It should be possible to simply stick an arm into the t-line on these larger models and check whether or not the egg crate material continues or changes)
 
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Somehow my brain blocked out my knowledge of these speakers' internal structure for a bit. When seller said he could feel the change in the line's damping material I should have realized immediately that this manoeuvre shouldn't be possible due to the last wall in the line. Ignore the post above.
 
Yea, I know those links, thanks though.

The first DIY guy seems to be very open about not making an exact copy and not having all the details. JimPA's second post mentions that one shouldn't use egg crate foam, though this is solely what is used in TDL designs if the official drawings of the models are to be trusted. If I find out exactly what the replacement material is though that thread will probably tell whether or not said replacement is suitable.

I have only seen one image of a TDL speakers insides (here on this site actually), and that showed egg crate foam behind the driver. I pretty much assume that this is what one should expect to find in an original model, but it is problematic to base it on one single picture, so I was hoping to hear from more owners (though since the logic in my first post was flawed such info can only be obtained if someone removes a driver or opens the enclosure).
 
I think I will pull the trigger on these, even if the line is damped differently. However if the line itself is modified I will not. Cross your fingers :)
 
Yea, this was probably one of those deals where I should been more careful. Pictures on the add were low-res, and therefore didn't show any flaws and I accepted when seller offered to deliver them at my door (which was convenient since I don't have a car). I just missed an opportunity to buy the subwoofer matching my current active monitors, which is very rare, and clearly my urge for new gear got the better of me.

First of all I must say that I haven't heard the speakers yet. Im picking up an amplifier tomorrow (currently only own actives). Im posting my impressions of them as a way of describing the speakers and hope some of you will give an estimate of their worth based on this and perhaps some insight on the mid range driver issue.

On the positive side the cabinets seem to be of high building quality and finish. I do believe that the inner measurements are original (outer measurements are larger due to added damping with sand and of course the baffle is modified slightly). I would estimate that they weigh closer to 60 than the originals 47 kg. Woofers are original and looks good.
(Most positive thing right now though is honestly how I got the speakers up in my apartment. Seller and I were unable to get them up the stairs so I called my friend and long story short he had a girl over for dinner and still came to help. True friend right there, bailing his idiot friend out :) )

The negatives are a slightly dented tweeter (this I knew) and more importantly that the mid range drivers are not identical, which was a big surprise. I didn't notice before seller had left when I got them up in the apartment (at closer inspection I realized that the surrounds and dust caps are clearly not the same and one is noticeable tighter). Seller claims that the speakers were a custom job ordered from a semi-professional speaker builder he knew personally and that he never noticed any difference (I called him up when I saw it). Honestly he seemed like a decent guy and Im not sure what to think of the situation. It really took away my initial joy with getting them though.

How much should I have paid for these?

(the weird hue on the pictures, especially the woofer, is just my sucky mobile camera)

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It would be great if someone could identify the original mid range driver (unless they're both ****ed). If one is original I'll try and find an original spare for the other speaker. Ugh.

Could it be that they are both original, but one of them has been repaired? It could look like the dust cap in one of the drivers has been repaired and perhaps at the same time a torn surround could have been replaced with a new softer one...
 
Wild, they look like early Studio 4's based on the driver layout, but I've never seen a trapezoidal cabinet like that for a TL. I guess that was his take on it. I wonder if they even have a full line. I guess they could but why the trapezoidal flare, I thought that was only used in a Reflex or Ported Cabinet Design?
 
They should be modelled after TDL Monitor and use TDL monitor driver units (though as noted I was tricked on that one as atleast one of the mid range drivers is not original). The baffle is made a bit thinner, kinda like the TDL Reference Standard, but when I feel on the inside the line is square and the internal width is the same as the internal width of the TDL Monitor. The trapezoid form is only on the outside, since there is added extra damping to the cabinet (hence these are wider than original Monitors).

The line is damped with a material more like rockwool than the egg crate material in the very end of the line, but this does seem to fit with the official TDL DIY kit (containing drivers, crossover and damping material). I know this from an article I found where a hifi magazine build the Reference Standard from such a kit and the line dampening is shown.

https://tdldiy.files.wordpress.com/2012/05/tdl_artikel_1.jpg
 
SimpySound what is the round disc between the mid range surround and the 4 screws holding the driver made of on your Studio 4s? In my pair one is metal and one is rubber.
 
No, I didn't. I might at some point, but since I don't really feel like buying an expensive replacement driver at the moment, there's really no upside to doing so right now. But I appreciate the list and I have saved it for later, thanks.

Due to a series of annoying events I have actually not even listened to them yet!

The temporary amplifier I had acquired is acting up and the shipment with my cables was delayed. Might have to buy some banana plugs too, as running bare wire through the bi-wire terminals proved more difficult than I anticipated. I am sincerely appalled with the quality of hifi cables.
From ABX testing of pro audio cables I have long ago decided not to pay for expensive cables and so I chose QED 79. The jacket is too stiff and too tight and the strands are super flimsy making it near impossible to strip a large portion of the wire without breaking a few of them. Yes, it is a cheap cable, but go to any store selling musical instruments and you can pick up a few metres of thick, flexible and shielded cable with high quality plugs (Jack/XLR) for the same price. It is absolutely insane. Im starting to remember why I haven't had a hifi setup since I was a teen...

Im in too deep to quit now though, so Im trying to find a permanent amp for the setup asap (making the temporary amplifier and the bottle of contact cleaner money straight down the drain). Hopefully I'll bring home an amp soon and return with good news :)
 
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