TDL Speakers - Pls. Read & Share Your Thoughts


I have been using TDL REFERENCE STUDIO MONITOR 'M' speakers for quite a few years now.They have kept me very happy & content through these years .

TDL speakers are rarely spoken of & i know only a few people who own them. I thought it will be interesting to share the experiences of pepole who have owned or heard TDL speakers.

IMO TDL's ref monitor's are very well balanced speakers.I have heard quite a few expensive and well reputed speakers in the $10k - $20k range, but none has made me want to give up the TDL's. Some were good at doing one thing well but the overall picture was somehow not complete. Many of them fell far short in the lower frequencies and this is where the TDL's trully excelled, reaching down to nearly 18 Hz.

I guess as with any system matching is crucial and i found tubes to be the best match but to enjoy the bass depths these speakers reach you need SS control. I settled for a Supratek Chardonnay tube pre with a Mac MC352 power amp. This combo works *** MAGIC *** for me. I have something to look forward to at the end of every day. Something us audiophiles have in common i guess to keep us sane in this crazy world. Sit back and let it flow !!!

I would love to hear from any A'gonners who have owned or experienced these trully special speakers. There's next to nothing to be found on the web about TDL's so i think it would be nice to start a thread on this one time great company.

Pls. pay your tribute to " TDL " by sharing your experiences with ANY TDL model you would like to mention along with various sys. combinations you might have tried on them.

From a TDL fan !!!
HI Dilly, I'm YOT from Thailand. About 12 years ago I've bought the Studio one from HongKong, with The Preamp n Typhoon[power amp] of Musical Fidelity. Just 60watts/ch. They drive the Studio one as well,they're too small,but they can go down deep by a merit of wonderful transmission line system.
I sold both of pre and power-amp several years ago, still keep the Studio one. Last year I try changing all of wire in the speaker with Cardas wire [for modify ]. The sound comes alive,everything's improve even drive them with the quite cheap amp-made in Thailand. Although they're too old, I still loving them.
Regards / YOT
Hello Yot.
Nice to hear from another fan. I have heard the
Studio 1'M' . I am not suprised you have kept them for 12 years.

Thanks for the tip on the Cardas wiring. Is there a particular type you would recommend ?
This was a long term option i was considering as well.
Also have you considered vandenhull cables before opting for cardas.

Dilly, Just as solid 14gauge wire , there r in both of blue n red insulator for modify. I bought them at Cardas's dealer in Thailand. [ For more detail,u could contact to Cardas in USA directly.]
VDH is fine with mid-range,but bass too slow [ clumsy, I think ] It's not suit for transmission line. Cardas made all of sound improve noticeably, tighten bass,n deep bass can go down deeper than ever,marvelous mid n high.
Should let them work as usually,about one month later. its merit would gently emerge.
Regards / YOT
Hello folks,

I'am also a, very satisfied, owner of a pair TDL reference.
I settled for a Aitos line-tube pre-amplifier with two Aitos OTL-mono's power amp's for de mid/high section and a Aragon 8008ST for de bass units.
Hi all.
I just came across this thread, by accident, and decided to add my thoughts. I am the proud owner of TDL Reference Studio Monitor M's, TDL Studio 4's, as well as IMF RSPM IV's, IMF TLS 50 II's, IMF ALS 40 b's, a couple pairs of IMF Super compacts, and several pairs of Frieds.(Model H, A3's, Model R's and several pairs of Q's. IMF was the predacessor of TDL, and Irving M Fried was the founder of IMF, who also sold speakers with the Fried Products badge.
The TDL's, IMF's and Frieds all share one thing in common. Their tremendous, deep, powerful transmition line bass, and incredible bass slam. Once you hear it, you never forget it. And once you have lived with it, it is really hard to live without it. They are all very natural sounding in the mids and highs, with great extension on the M models. The early models all benefit greatly from cap, resistor and wire upgrades, because of the type of caps available when they were designed and built. All in ll, great speakers, from a great company. By the way, they are still being built today, by AOS, i believe, in Germany. They are expensive, however, starting around $10,000 a pair. Regards to all.
Hello Rico,

Nice to hear from another fan! You have a vast collection!!!

Recently met a gent who had owned IMF top model (can't remember the model) 20 years ago which he had to let go way back. He mentioned he has been missing these for nearly 15 years since then. Recently he found himself a pair of Reference Studio Monitor M used & said this will be his "last set of speakers"! I know he meant it though we audiophiles tend to use this term a lot. Just thought I would share this.

I too have another TDL pair. A pair of Studio .5 M. Supposed to be "worlds smallest full Transmission line speakers" according to their brochure at the time.

Oh and this Kharma Grand Ceramique review gives you an idea of how good the TDL Reference bass really is.........
I own a pair of the TDL Reference Standards and both woofers on the left channel are damaged, (One has an 8 ohm voice coil and the other has a 16 ohm voice coil). I am aware that TDL and Elac, who made the drivers both went out of business years ago and the biradial woofer are particularly difficult to come by. I am looking for replacement drivers or someone who can repair them. If this is not possible, I will sell them for parts. All the other 12 drivers and crossovers are in good shape. I even own the original boxes and packing materials.
Hi, its nice to hear from other TDL owners who are happy with their speakers. I have a pair of TDL Monitors's (the model below the Ref Standard) - is this a different model from the Studio Reference Monitor - i haven't seen or heard of this model - does anyone have a pic they could post, host or point to? I also have a pair of Studio 1's and a pair of Studio 1's with the 'M' drivers (but not in Studio 1M guise). I bi-amp the Monitors with an Audiolab 8000A and a 8000P and use the original Exposure cd player and a project deck as sources. Very happy with the TDL sound and deep bass extension, jsut need to find some original stands for them. Cheers, Mark.
have had tdl ref mon for 18 years they are truly mag had my woofers out to check last week i was supprised to find 1 woofer was 16 ohms and 1 was 8 ohms in each of the speakers can anyone tell me is this correct mike arnold 15.4.07.
Hi Everyone I am also a proud owner of a set of TDL standard reference M and i have over the years brought and sold 1000s of speakers and none have been able to match the realism of these speakers they are outstanding in every way there production of sound can be summed up as follows MAGIC! The sound is fast and tunefullyet not bright; it is open and clear with so much midrange detail you will think the band is in the room with you, fatigue-free and grain-free allways sounding like you have only just started listening and still have hours of enjoyment ahead of you. Bass notes are precisely defined, deep and tuneful and they deliver right down to 14 HZ when correctley partnered and the bass hits you with amazing impact. The midband, especially vocals and solo instruments, takes on a naturalness never before heard from a pair of speakers they are truly inspireing. The treble is smooth and fast with both brilliance and sparkle. But the speakers never sound bright, brittle, grainy or spitty. They just sound ‘right’. They are in my opinion one of the greatest speakers in the world and represent the pinnacle of Transmission line speakers, The bass units run individualy from the crossovers one on 8ohm and the other on 16ohm so that you recieve the full bass range as the speakers ressonate slightly differently at diffrent ohm inputs, The tweeters go upto the dizzy hieght of 35khz without sounding harsh which is quite some task, If you get the chance at owning a pair of these speakers you will be utterley amazed at the pressence and impact they realy will change your life.
I am from UK. I own TDL Studio reference 1M since 1996 and they are great! There must be a good reason one rarely comes across TDL Studio/Reference range in the 2nd hand market or on Ebay. Very relieved to come across your good selves equally satisfied with the TDLs! I'm really sad they went out of buisiness. US maker Shannian Acoustics use Transmission Lines too. There is a German who builds Transmission Line speakers following the TDL but not quite the Refererence/Studio range.
I own a pair of TDL Reference Standards circa 1993. I would like to replace the capacitors and I would like to find a 16ohm replacement tweeter. Do any of you have any info relative to either? Thanks
I have the XO schematic and other documents on the RSTL. A good resource for parts for the RSTL is DHS Speakers in Saginaw, MI. You should be able to source anything you need from DHS. 

Are yours the original RSTL's or the later RSTL-M?

Hi all,

Hi mre28m5 - is that a reference to the old BMW? My favourite car ever, wish I could find a good one of those!!! I had a couple of e28 M535

I digress.

I recently bought what I though were a pair of TDL Studio 4 - but I’m told I actually have a pair of TDL Studio Monitor M - which is not a model I was aware of before, and I am finding it hard to find information on the net about these - Apparently they were released at the same time as the "M" revision of the RSTL. They are a 3 way, very similar looking to the Studio 4, but with a metal midrange driver.

Anyway, they have had a somewhat chequered history. The crossovers have been replaced with something home-made, for whatever reason, and the bass drivers are currently running about 6dB down, so I am running them bi-amped so I can separately control the level of the bass driver. I would love to return them to original spec, but its very hard to find info. Does anyone here have circuit diagrams for the original crossovers on these?

My bass drivers are Elac 3021GT 01 (8Ω) - I was expecting these to be GT 03 (6Ω) as per the spec of the Monitor and Studio 4? Does anyone know what the correct driver should be for these?

The mids are unmarked but share the same chassis as the bass drivers in my 0.75M - so they are an Elac unit and do have the correct metal cones - but they do not have the phase plugs as shown in the original launch brochure, instead they have a generic dome dust-cap. Not sure whether this is the result of a repair, or a later revision to the spec of the drivers.

The HF drivers are Vifa D25AG-67-06 (6Ω) - which I am assuming are replacements, and possibly the reason why the original crossovers were replaced??? I was expecting to find some variant of the Elac 25DT, like the rest of the TDL Studio & monitor range. But if anyone can confirm what the correct driver should be, that would be helpful.

If anyone has any info which would help me restore these back to original spec I would be very grateful. Elac 25DTs are hard to come by, but not impossible - but I really need the circuit diagrams for the original crossovers so that I can make a pair. (or the crossover for the RSTL M, I might be able to extrapolate)

many thanks,

Hello Dan,

I started this thread 14 years ago, it seems so long ago. My systems have gone through numerous changes but happy to say the TDL Studio Monitors are still with me! I still like them as the day I brought them home and they are still in excellent shape after all these years. They are truly speakers for the long run.

Regarding the bass driver I can confirm the model is 3021 GT03. As I understand they will be very difficult to come by. I believe the KEF B139 driver is a direct replacement. TDL has improved the performance over the B139. I am afraid I don't have any information on the crossover circuit diagrams to share. The TDL Studio Monitor 'M' speaker, the fronts of the speaker is also vineered as the sides where as the Studio 4 it looks black. I presume yours is the former with front veneer. 

I came across some information on the TDL's on AVS Forums, you can have a look. You can also contact Falcon Acoustics for suitable replacement drivers. Falcon also has a white paper on the driver specs. 

I hope you will be able to restore the speakers back to the original condition. They are worth the effort IMO.

If you come across any more information please do post it here for the benefit of other TDL owners. I wish you best of luck with the  restoration!