Chris Rogers PRO9-TL Transmission Line speakers experience
On Saturday I collected a pair of Chris Rogers PRO9-TL Transmission Line speakers from Neville Roberts. Neville has written HiFi reviews in several magazines for a number of years and is well respected in the HiFi and music recording industry. The speakers have been his pride and joy since he had them built in the 80's, he told me that they are around 30 years old. Neville had the cabinets professionally made by a carpenter/cabinet maker who also veneered them and completed the build himself fitting the crossovers, wiring, drivers and binding posts. They are a credit to him and you could consider them to be professionally made.
As reported by Nevile "They have been significantly upgraded over the years with new Audax HD12 tweeters fitted with Russ Andrews’ Focus Rings and new Peerless K040-MRF midrange, all replaced recently. The switches of the crossovers have been removed and then completely rebuilt with audiophile components throughout, including ClarityCap polypropylene capacitors, Mills audio grade resistors, and Mundorf 99% silver/1% gold wiring." The removed switches Neville told me were replaced with high grade resistors to maintain and neutral setting, the crossovers being built to the original design spec, the new tweeters and mid drivers are as the originals.
The cabinets are in excellent condition no knocks or bashes to them, in a few places the veneer has bubbled slightly but at present I am not too concerned with this, but will probably redo the veneer at some point. The cabinets are 340(w) * 470(D) * 970(H) or in old money 13.5" * 18.5" * 38.5" and weigh in at around 35kg each, so quite a substantial foot print by modern day standards and possibly challenging in a modern house or on the SWMBO front.
Some of you may be wondering why I would purchase such a speaker, the answer goes back to the late 70's when I was getting into hifi, even though I could not afford much at the time I was an avid reader of several HiFi magazines. I recall reading a review of the Chris Rogers PRO9-TL's which praised them greatly in terms of the openness and accuracy of the sound they produced along with very controlled bass. (I know some people do not like the KEF B139 bass drivers used in them, and others love them, I have no opinion on this subject and come to them with open ears.) Being in my early 20's at the time I did not have the skills, money to build a pair, or a suitable place of my own then, so as time passed they slipped into the recesses of my mind. By chance I saw this pair come up for sale on AoS, I immediately new if possible I should try to get them and try them out, Sue's permission was gained first, and they are an early Christmas pressie.
These are my findings to date which I have also reported to Neville.
On my return from Neville's, Sue helped me in with the speakers and I set them up in a temporary position and listened quickly to a couple of favourite tracks. Taboo from The Guitar Artistry of Charlie Byrd (a must have album in my humble opinion), lots of drum solo work and great guitar and bass breaks. The other track was Botannical Dimensions from the album “Nothing last …. But nothing is lost by the Shpongle, we’ll worth a listen to this one if you can stream, it’s on Qobuz, Tidal and Spotify.
My initial reaction was “Well these sound rather good, quite a lot of depth to it all”. It was then time for tea and relax for the rest of the evening.
The following morning I moved the Wilson Benesch's to the spare room and moved the Rogers PRO9’s into what I thought would be the best position. I then had a few jobs to do and listening had to wait till the afternoon.
I listened that afternoon to the tracks below on vinyl and one on CD(Strauss). I used these as they are all well know pieces for me each with different aspects of music, styles/genres, covering various instrumentation (real, electric and synthesised), and are all generally very well recorded. The Eva Cassidy, Ravi Shankar, Paul Simon, Sinéad O’Connor, Hugh Masekala, and Charlie Byrd are go to tracks for me to see if my system is performing as I would hope.
Peter Gabriel - "The Rhythm Of The Heat" & "San Jacinto" from IV(Security) - PGCDR4
Michael Hedges - "Aerial Boundaries" & "Bensusan" from Aerial Boundaries, Windham Hill Records – 371 032-1
Paul Simon - "The Boy In The Bubble" & "Graceland" from Graceland, Warner Bros. Records – WX 52
Charlie Byrd Trio - "Taboo" from The Guitar Artistry Of Charlie Byrd, Riverside Records – OLP 93007
Supertramp - "School" & "Bloody Well Right" from Crime Of The Century, A&M Records – AMLS 68258
Sinead O’Connor - "Feel So Different" & "I Am Stretched On Your Grave" from "I Do Not Want What I Haven't Got",Ensign – CHEN 14
Alan Parsons Project - "I Robot" & "I Wouldn't Want To Be Like You" from I Robot, Mobile Fidelity Sound Lab – MFSL 2-455
Hugh Masekala - "Stimela" from Hope, Analogue Productions – APJ 82020
Shpongle - "Botanical Dimensions" from Nothing Lasts... But Nothing Is Lost, Twisted Records – TWSLP28RM
Miles Davis - "So What" from Kind Of Blue, CBS – BPG 62066
Eva Cassidy - "Fields Of Gold" & "Baby I Love You" from Nightbird, Blix Street Records – BOX20142
Ravi Shankar - "Tala Rasa Ranga" & "Dhun" from Portrait Of Genius, Fontana – TL 5285
St, Germain - Tourist (all of it while writing this today) Parlophone – 5099963622010
Vivaldi - The Four Seasons, La Primavera (The Spring) Allegro & L'Inverno (The Winter) Allegro Non Molto from Antonio Vivaldi, Nils-Erik Sparf, The Drottningholm Baroque Ensemble – The Four Seasons, BIS – LP-275 (a rather wonderful recording and rendition)
Richard Strauss - Also Sprach Zarathustra, Op. 30 - Prelude (Sonnenaufgang) & Von Den Hinterweltiern, from Los Angeles Philharmonic, Zubin Mehta, Lim – LIM K2HD 035
J. S. Bach*, Peter Hurford – The Organ Works Volume 1 & 3 Argo (2) – D120D 3, Fantasia And Fuge In G Minor BWV 542 and Prelude And Fugue In G BWV 541
The listening experience with the PRO9 TL's as I find it is a very pleasing one which I will try and impart as well as I can.
I am rather shocked, stunned and very impressed by the speakers. I was not expecting them to sound so natural and musical. As I have listened I have realised that they give an extremely good insight into what is recorded, I am hearing more detail and clarity across the board. Some quite stunning aspects are the quality of attack and the sense of rhythm they achieve, along with great depth and control of the low end. For example on the Charlie Byrd's "Taboo" and Miles Davis “So What” I can hear the playing of the bass strings with clarity and decay of notes, giving an un-muddled presentation.
There is a great musical rendition across the board, as if the speakers are not in the room, just the artists recording, super! With Sinéad O'Connor's "Feel So Different", a favourite of mine, it is primarily some double basses and a section of cellos, that are plucked and bowed to great effect through the song, this rises to a crescendo at the end and it can easily become unclear and a wash of sound in the lower registers, not with the PRO9 Tl's, it all remained in focus and clear with Sinéad's voice sounding beautiful.
With respect to low end, Neville said he had measured the speakers down to 20hz before they roll off much with REW on a computer and a high quality calibrated mic, and I am pretty confident this is the case, the Strauss and Bach pieces showed this perfectly, what I did not expect was the amount of control and detail in the low end, which is excellent. As for the mid-range and upper frequencies, to my ears the speakers are performing very, very similarly to the Wilson Benesch Vectors, a rather expensive modern design with a reputation for clarity and purity of tone, so to get this from the PRO9's which were designed over 40 years is a truly pleasant finding, it just goes to show that some people were doing great things in the HiFi world in the 60's and 70's.
To sum up the Chris Rogers PRO9 TL's IMHO are a great speaker, giving a very natural and musical presentation, very easy to listen to drawing you into the music. For me they achieve what a speaker should, when listening it is as if they are not there, just the artists recording. One word of caution I do suspect though that when I put on a poor recording on they will highlight any inadequacies, so that could become costly.
I would add that I think my Krell KSA-80 power amplifier is a very good match for them as it has oodles of damping factor and ability to give loads of power and control when needed, so I would recommend similar amplification if you are tempted to find a pair of these speakers or even make some. Nevile was using a pair dual mono 300B's power amps with twin 300B's in each that gave more power, I think over 20w, and control than a simple 300B SET would, and these obviously worked with the PRO9 TL's or he would not have used them.
All I need to do know is to sit back and enjoy the music.
Finally a very big thank you to Neville for letting me have his speakers, it couldn't have been easy to part with them after 30 years.
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Originally Posted by Beobloke
