PMC transmission line spkrs. Any observations or experience?
- Thread starter Mike Reed
- Start date
Mike Reed
pfm Member
I bought the .26s because one of my 2905s is down and I can't get it to Huntingdon until the spring/early summer. When it's fixed, I'll have to make a choice, as keeping either pair redundant is not an option and not just because of space.
A decade ago I bought a local used pair of 57s as an experiment in finding out about ESLs. I liked what they did but found them far too small scale (esp. after gigantic ProAc R4s. I thought ' maybe big Quads will do it'. A nearly new pair came up in a Scottish dealer's and I grabbed them. They did indeed do what I wanted; to such an extent that the ProAcs, languishing in my porch for some months, when set up again (not easy with 133kg (each) spkrs) sounded awful. Obv. the ESL magic had worked.
A friend lent me his 57s in Oct./Nov. and the same situation occurred, where I could use them for gigantic headphones, as it were, but they couldn't fill my room with music. They also took up far too much awkward space. I actually found that a cheapo pair of Gales (Richer Sounds) picked up locally from Gumtree did a better job from the p.o.v. of imaging etc.
Mike Reed
pfm Member
Mine are not bright at all, though they are driven by valved monoblocks. Obv. more demonstrative in the treble than the Quads, but well within frequency cohesion overall.
Dingbat
pfm Member
My Twenty5.26s were so horribly bright at the start that I actually had to massively toe them out in order to get them vaguely listenable. It took at least 500 hours for them to burn in properly. As long as they're properly run in, they should not be bright. Now I have them more or less shooting straight down the room, with only a very slight toe-in, of the order of a couple of degrees. Toe-in any more than that, and the sound quality seem to degrade.
Big Tabs
looking backwards, going forwards
Big Tabs
looking backwards, going forwards
agreed.
Mine do not sound ‘bright’ whether toed-in or not.
(silk domed seas tweeter)
Spraggons Den
pfm Member
No treble brightness here.
tuga
Legal Alien
After 500 hours you’ve gotten used tongue brightness.
All measurements I’ve seen seem to point to an inherent brightness.
But beauty is in the ear of the beholder and I am inclined to say that, judging from their speaker choices, most audiophiles seem to prefer a slight to pronounced forward and bright sound.
foxwelljsly
Me too, I ate one sour too.
If PMCs have a house sound, it's punchy and loud with a hint of boom-tish. Along with Monitor Audio, Linn and Royd, in that group of great speakers that I've tried but couldn't live with. That said, I'd still like to try some on my desk where these things can be a bonus.
The only conventional speakers I've heard which do some of the ESL thing, but go louder and lower and have a less vice like sweet spot, are big Kef Reference monitors or Meridian Actives - which are what I have now. I am sure there are others, though
The only conventional speakers I've heard which do some of the ESL thing, but go louder and lower and have a less vice like sweet spot, are big Kef Reference monitors or Meridian Actives - which are what I have now. I am sure there are others, though
tuga
Legal Alien
It's ultimately impossible for conventional speakers to do the ESL thing because ESLs are dipoles. The closest you get with cones and tweeters is an open-baffle topology like the Jamo R907/909 or the Gradient 1.5.
Mike Reed
pfm Member
Sounds like you have an elongated room like me. What's the rough distance between your hearing position and the front baffles? Are yours well apart or not? Mine are 6'9" (2.06 m) apart, front inside cab. and between 13'4"to 13'6" (4.1 m) ears to baffle, so more or less an isosceles triangle where the sides are 2x the base.
A worthwhile addition to the lexicology of audio sound; highly commendable as it speaks volumes !
Dingbat
pfm Member
The speakers are 3.1m apart. When sitting on the couch, laterally back from the front baffles 3.5m, actual distance along the triangle around 3.7 to 3.8m. This spot is actually a little too close, the soundstage is a bit better about 1m back from this. At some point, I will rearrange things so I can push the couch further back.
Mike Reed
pfm Member
Not far off an equilateral triangle, then. All my speakers have been at elongated isosceles triangles as I've always found that this fills the room and spreads the soundstage/imaging. Think you'll find an extra metre beneficial, as long as you still leave enough (2' ?) behind the sofa.
darrenyeats
pfm Member
I try to keep my listening position at least 1m into the room.
ToTo Man
the band not the dog
"Brightness" is an inherently vague term IMO. Some people associate the term brightness with an accentuated overall treble response, whilst others associate it with a particular area of treble - most often the 4kHz-8kHz region. PMC's rising on-axis treble response affects frequencies above 8kHz, so doesn't add the glary sort of brightness that an accentuated 4kHz-8kHz does. It instead adds crispness to the leading edges of transients and a heightened sense of air that can be pleasing to many.
Given that most folk's hearing is much more sensitive in the 1kHz-8kHz region than 8kHz-20kHz, a sensitivity imbalance that worsens with age, it's not surprising that a lot of audiophiles aren't troubled by an accentuated top octave, but just because you can't hear it doesn't mean it isn't there in the speaker's voicing!
A few years ago I parted with one of my pairs of Goodmans Achromat Beta mini monitors because the tweeter had drifted off spec and developed a fairly narrow but high +10dB peak in its response at 13kHz that made it uncomfortable for my mid-20 year old ears to listen to. Now that I'm in my mid-30s and have lost some more of my sensitivity to high frequencies I suspect this peak would no longer bother me to the extent that it did.
PS - @tuga, I wouldn't say that the domestic PMC models have a "forward" voicing as such. The BBC-style saddle between 2kHz-4kHz actually makes them sound more laid-back and distant in the upper midrange than forward and up-front.
Given that most folk's hearing is much more sensitive in the 1kHz-8kHz region than 8kHz-20kHz, a sensitivity imbalance that worsens with age, it's not surprising that a lot of audiophiles aren't troubled by an accentuated top octave, but just because you can't hear it doesn't mean it isn't there in the speaker's voicing!
A few years ago I parted with one of my pairs of Goodmans Achromat Beta mini monitors because the tweeter had drifted off spec and developed a fairly narrow but high +10dB peak in its response at 13kHz that made it uncomfortable for my mid-20 year old ears to listen to. Now that I'm in my mid-30s and have lost some more of my sensitivity to high frequencies I suspect this peak would no longer bother me to the extent that it did.
PS - @tuga, I wouldn't say that the domestic PMC models have a "forward" voicing as such. The BBC-style saddle between 2kHz-4kHz actually makes them sound more laid-back and distant in the upper midrange than forward and up-front.
If I may, my tuppenceworth. I first heard PMC speakers something over 30 years ago when I was working in professional audio and having just left the BBC. At that time they only made the BB5, obviously only intended for large recording and dubbing studios and the newly introduced LB1 for smaller locations. That was it and absolutely no crossover into the audiophile/domestic hifi world. I was blown away by sound from such a small loud speaker and indeed a lot of my former colleagues felt that it was similar to the LS3/5a but with top and bottom. To this day I think it one of the finest small speakers produced for a domestic market in the last 50 years, even if not originally intended for there. It took me a long time to get a decent example but I have a mint pair with a new grille coverings that sound wonderful.
What has changed is my hearing which at nearly 70 no longer hears much above 10kHz so the LB1's sound a little bit lifeless compared to former days whereas the 25.23Is in the main system, with a "bright" top give me a decent reproduction that I like. The amplification is Quad so relatively neutral and I have no particular desire to change anything.
It is completely unfair to both manufacturers to compare PMC and Quad ESL speakers, they both have strenghths and weaknesses. The ESL's biggest drawback in my view is the space needed for them, something most post war housing lacks.
At the end of the day the music being listened to is far more important than the reproduction equipment.
Regards
Martin
What has changed is my hearing which at nearly 70 no longer hears much above 10kHz so the LB1's sound a little bit lifeless compared to former days whereas the 25.23Is in the main system, with a "bright" top give me a decent reproduction that I like. The amplification is Quad so relatively neutral and I have no particular desire to change anything.
It is completely unfair to both manufacturers to compare PMC and Quad ESL speakers, they both have strenghths and weaknesses. The ESL's biggest drawback in my view is the space needed for them, something most post war housing lacks.
At the end of the day the music being listened to is far more important than the reproduction equipment.
Regards
Martin
Mike Reed
pfm Member
Maybe and debatable, but enhancement of music relies upon the reproduction kit etc., unless induced by other means. I'd say they were interdependent in the music/hifi world rather than being exclusively comparative.
Dingbat and others on this thread, I'm indebted to your suggestions of 'straightening out' the cab's rather than toeing in. I really was a wee bit cynical, but tried it yesterday for a 3 hour radio and vinyl session as I said I would.
I was amazed at the difference such a small angle change can bring. Immediately, there was increased holography, yet with seemingly more detail in disparate parts of the soundstage. Absolutely no hole in the middle either, and it certainly raised the level of my .26s to a point where I really started enjoying them rather than just admiring them, as they were pretty damned good previously.
I shifted around on my 3 seat, 7 foot sofa and the soundstage etc. was barely (if at all) influenced by my moving along a 6' plane. One slight caveat, although to my ears this was not unpleasant, was a higher treble output from sitars and other treble accentuated instruments. Some may say it verges on the 'steely' but to me it accurately reproduced the frequency excitement these musical interludes can elicit.
I've had quite a few large and expensive speakers plus small ones, but these PMCs are, especially considering their size, a cut above and oozing quality all round. The bass is fully controlled now, but of course that depends upon the software content. Happy bunny but will they oust the 2905s eventually/ My wife hopes so !
Last edited:
tuga
Legal Alien
I would say that the "steely" quality should only be present in sound sources/instruments which sound like that in reality.
Personally I would only use that term to describe a bad quality or issue.
Err no and irrefutably so, if the equipment is enhancing anything it's doing so wrongly, perhaps you meant enjoyment. The equipment is just a means to an end and once it means more than the music then you have changed hobbies. Perfectly reasonable thing to do but then it becomes a race to spend as much as possible chasing the unattainable, you may care to do that, I have neither the means nor interest to do so. I'm also not persuaded by the term holographic which if anything relates to the visual sense rather than anything aural, in fact I'm generally agin vague subjective adjectives to describe sound quality because ultimately it's only relevant to the person using them originally. Hifi magazines have a lot to answer for in their bastardisation of the english language.
Nearly 60 years ago one of my introductions to my own choice of music was Johnnie Walker on Radio Caroline, medium wave of course, 4.5 kHz bandwidth and constant ionospheric fading, all these years and several thousand pounds hasn't improved Marvin Gaye or Solomon Burke one iota. Once I realised that expensive equipment is largely a marketing exercise to open wallets hifi life became so much simpler. This is of course one of the downsides of being an engineer, natural scepticism and accepting that the laws of physics are immutable rather go with the territory.
I think we would agree though, PMC make good quality loud speakers that may not be to everyone's taste.
Regards
Martin
Mike Reed
pfm Member
Of course I referred to enjoyment, although enhancement = exaggerate, elevate or appear greater (originally) and also =intensify, increase etc., , so I really didn't need to qualify my usage.
.
Don't know about you, but with good kit, some music takes on a visual interpretation, albeit within one's head.. Holographic is the adjective for holograms (sth forming a 3 dimensional image). I neither invented nor was responsible for assigning this word to the 3D aspects of stereo imagery but for me it is extremely apposite.
To veer away from semantics, I had just been listening to Johnnie Walker's 'Sounds of the 70s' (R2) when I read your reference to him. Not sure when R.C. operated, but unless it was before 1964/5, the s.q. was too poor to take seriously. By 1969/70/71, stereo FM was quite superb; sufficiently good to be transcribed to tape.
I have to say that my first, say, decade in owning decent hifi (1964/5 to '74/5) was, even then, bought at little expense and represented good v.f.m. I feel that it's only in the last three decades that subjective value of higher end kit has been over-hyped. I remember 401s and Thorens, SMEs, Shure V15s et al which I had at college were absolute snips, albeit at wholesale !
Their input has been but a tiny part of a general decline in English language speaking, syntax and grammar etc. Anyway, I gave up buying them when CD coverage outstripped analogue.
Last edited: