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PMC transmission line spkrs. Any observations or experience?

When bought new, my Twenty5.26 was super bright to the point of painful, and where I was living at the time, the room acoustics were terrible. I thought I made a big mistake. Now though, I'm in a different place, it is sitting in a 8m x 5m room, positioned on the short side of the room, firing down through the long length of the room. It sounds excellent now, very precise sound, no overt brightness, the bass is taunt and has no bloom.

There could be a few factors going on here. I have my speakers sitting on Isoacoustics Gaia III - they made a big difference to improving the sound quality. I have them 40cm from the back walls. I experimented a lot with positioning, and found a little more or a little less from the back wall changed the bass quality markedly. At that distance from the wall, it seemed to give the best controlled bass. Theoretically they can be close to the walls, but a little bit of air around them helps. Too far into the room though, and they started to get a bit limp. I'm currently using a Supernait 2 integrated amp with a Hicap, and that drives it beautifully.

So it could be a one or a combination of room acoustics, speaker positioning and support, or amplification going on there - or maybe the sound simply isn't for you. The PMCs grew on me. Over time, I came to like more and more the sound I was getting, especially with my amplification. It's a very precise, but not analytical sound, it renders both rock and jazz very well, times great, and the bass is taunt and accurate. If it's there in the music, it is there, but it won't show you something if it isn't in the music. And I don't feel that the music it plays is coloured in any way.
 
Before buying a pair of used Twenty.26 (largest in that range)I did due diligence, reading a dozen reviews and other forum comments. Not one detracting remark was found. Furthermore, I, along with other friends, were impressed by the PMC room at an East Anglia show 5 yeas ago

Unfortunately, I came from 10+ years of ESL 2905s (big ones) which in all fairness, was going to be a culture shock of sorts but having had 45 previous years with big and expensive coils, I thought it would simply be a reversion to type, as it were. The PMCs are also very room-friendly in taking up less space, which = wife friendly too !

There's no question that these are superb speakers (AND for their size); imaging, soundstage, dynamics, cohesion etc., powered by my 100 W EAR monoblocks.

However, there is sth; maybe I've become ESLed, or the 'wall of sound' effect of the ESLs is more important than I realised; I don't know. Can't fault them but can't quite seem to gel with them either; maybe it's that prodigious bass? BUT I've always been a bass man, though I'm now above 80.

I intend to get my faulty ESL repaired in the spring, which'll give me a yardstick to work on, but wanted to sound out pfm to see if I've missed sth. YES, I know about the old 'once into ESLs, always into ESLs' syndrome !!!
As you know Mike.... I've struggled in a similar manner lately. Its just hard to go from panels to boxes. You tend to hear the box just a little too much.
 
Pretty much, every speaker I’ve owned has been PMC’s. To me, they do everything I like just right.

Currently running a pair of 25/21i’s and they are great. For a little box, I’m often astonished by how low the bottom end goes. You may find you may not need to go as big as the 26’s, the 24’s may be ok.
 
This my very personal comment from a vintage guy so just take it with a grain of salt..........

Personally, I really love the ATC floor standers with transmission line but the old ones, not those available today.

Back then, woofers were doped paper and tweeters were soft fabric dome. They were not the neck plus extra in terms of throwing a ton of details but they were very interesting to listen to for several hours in a row.
Very impressive bass with very low notes and well under control.

Unfortunately for my tricky ears, they now use some kind of carbon fiber woofers and metal tweeters that lost their sweetness according to me, making them a bit rough and they don’t surrender on poor recordings or digital sounding sources.

The driver used for the midrange is extremely detailed and and life like, which is their strength IMO, you can easily hear the singer breathing when not singing.

You need to know I listened to these powered by a solid state amplifier, could be different with valves.

For me, if I was looking for a very detailed speakers, I would look at Audio Physic or if you prefer deep bass, Neat should be under your radar.
 
Love my 20.24s. They are the piece of Hi-Fi equipment I have owned the longest and they work very well in my difficult room either side a chimney breast.
 
Interesting comments on PMCs, I’d consider a pair for my next speakers as they seem reasonably good value second hand but quite expensive new. Sounds like either the 24 or 26s would suit my room, 5x6x3.5m? Considering Neat Xplorer and atc 19 / 40s, anyone ever compared?
 
Tried FB1 and then OB1, forget what amp I was using at the time, probably a Naim 72/hicap/160. I found them visually ugly but liked listening to them enough to keep them for a year or so until the large Tannoy bug bit for a while and then Quad ESL63. I wouldn't go back to them.
 
Personally, I really love the ATC floor standers with transmission line but the old ones, not those available today.

Interesting, as I first listened to ATCs at a hifi show in Oxford St. in the mid (?) nineties. I always thought they were I.B.s (sealed boxes), either powered or passive. Never knew thy did transmission line. I had ATC drivers and mids in my ProAc Response Fours, so kept a 'connection' with ATC, as it were.

The PMCs grew on me. Over time, I came to like more and more the sound I was getting, especially with my amplification. It's a very precise, but not analytical sound, it renders both rock and jazz very well, times great, and the bass is taunt and accurate.

Encouraging, esp. considering your earlier experience. By 'taunt' bass d'you mean it teases you? :D. 'Accuracy' is somewhat objective, but PMC built their rep. on their studio analysis and expertise, so I cannot argue; however, musicality and involvement factors are important and I wonder if PMC strays a little to the side of neutrality in this instance; without, I hasten to add, the slightest signs of astringency.

Many interesting observations and experiences above, folks, for which, thanks. I'm a newcomer to PMC; bit of an experiment forced on me by defective ESL, and your comments seem to cover quite a lot of different attitudes. Obv. they're a curate's egg among spkrs. I don't find the bass, or anything else, unbalanced on mine, but they are half-way down a long room with about a foot to 18" to the sides , but not to solid walls. There are lots of crooks and nannies in my room, with record shelves built into the alcoves, record store wise (for browsing). Maybe my placement can be improved.
 
By "taut" bass I mean well controlled, high quality bass that punches, but does not arbitrarily pound. There are certain tracks, if I turn the volume up, I can actually feel the bass, which means there is real low end energy there. But the bass doesn't arbitrarily sound massive. To give you an indirect idea of what I mean, I walk past some houses where I live, and can the music quite loudly, sometimes from 50 meters away and through walls! Usually the bass is very apparent. So I guess these people are playing really bloody loud, probably on cheap home theater systems with massive bass, but it isn't the same as quality bass.

I have a home theater system too, with subwoofers. If I play music through it, I can get a bit more bass, but the quality of my HiFi system is way better.

I wouldn't use the term "analytical" for PMCs - that implies boring. To my mind, they aren't boring. By accurate, I mean they don't arbitrarily colour the music. If your source and amp can deliver, then it will come through on these speakers. I find them very enjoyable, and I generally prefer energetic, fast music with strong rhythm backing. This type of music, whether in Indie Pop or modern jazz, comes through on my system.
 
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My PMC experience is thus far limited to the Twenty5.24i. I was expecting it to overwhelm my smallish listening room in a similar manner to my giant IMFs but it didn't. I found the PMC's bass leaner and tauter by comparison. They've clearly put a lot of work into refining/optimising the TL loading to minimise woofer excursion. The cones barely move even with soundtracks with prodigious amounts of deep bass.

PMCs are still voiced with a BBC-style upper midrange dip and rising top end (though, AIUI, it's not as pronounced as it used to be), but this can be ameliorated if desired by minimising the amount of toe-in (i.e. pointing the tweeters straight ahead instead of at your ears). The tweeters on the new models at least are incredibly wide in their dispersion and produce a very wide sweet spot for imaging. I personally prefer a more neutral tuning through the midrange and treble but the way PMCs are voiced provides a generous impression of distance to the performance and makes the speakers and front wall appear further away than they are, which can be especially desirable in smaller rooms.
 
As you know Mike.... I've struggled in a similar manner lately. Its just hard to go from panels to boxes. You tend to hear the box just a little too much.

It is likely that you might not be hearing the box but the very distict directivity characteristics of a dipole vs. a monopole.
 
Thought it was a typo or whatever, but you're confusing 'taunt (=tease, entice, provoke etc.) with 'taut' (= tight) :)
Whoops, I must be getting dyslexic. Thanks for pointing that out. I was able to correct one of my posts, but can't seem to edit the other one.
 
I don't have experience with the recent PMC models. My experience with PMC was with the older models, LB1 Signature which I owned for several years and IB1 and EB1 which I heard in the showroom and at a mate's place.

Personally I find the bass of PMC speakers to be a bit too much irrespective of placement. I tried many amps with the LB1 Sigs when I had them and the speakers had a lot of space from the walls. I gave them more than 1.0 metre from the rear wall and the bass still sounded unnatural, sticking out like a sore thumb. The upper bass sounded forced as if it's forcefully pumped out from the box enclosure, producing an unnatural bass response. The larger PMC models EB1 and IB1 sounded more balanced but the bass still sounded a bit overwhelming which masked the nuance and fine detail in the midrange and treble. I find the PMC to be lacking when it comes to reproducing the nuance and fine detail in the music. I'm not sure if the current PMC models Fact series have improved on these aspects.
 
I'm not sure if the current PMC models Fact series have improved on these aspects.

I've no idea, though all the revies etc. which I read prior to getting the .26s suggested that their proprietary (new?) advanced t/line is a significant progression. Possibly, to back this up, not one mention of an overblown bass did I come across.

Despite being used to big ESL bass (not really outstanding albeit seamless), I don't find it overdone at all. Prodigious, yes; for a small (to me) box and in comparison with my ESLs and (from memory) previous very big ProAcs). I do recognise this excess bass trait is held by many (from older models) so maybe they have improved the design.
 
Having auditioned a few of the PMC floorstanders the thing I found across the range is that they have a very small listening window for optimal performance.

Change the toe in slightly, or shuffle across the sofa a bit and the magic is lost.

They sound excellent in the optimal zone but it really is an experience not sharable, so very much a "billy no mates" targeted product IMHO.
 
aving auditioned a few of the PMC floorstanders the thing I found across the range is that they have a very small listening window for optimal performance.
Change the toe in slightly, or shuffle across the sofa a bit and the magic is lost

Strange but I've not found this to be a problem as the imaging and soundstage is fine across my 7' sofa. Maybe it's my room/placement/distance from spkrs (5+ metres). Okay, they don't have the 'wall of sound' which my ESL 2905s gave, but that's to be expected from two utterly different designs (and size !!!)
 
Perhaps you haven't yet found the sweetspot?

It's pretty much where the axes cross if the speakers are toed in. No guarantee it's actually at the same distance as your sofa. You'll definitely know when you've found it!

I have to admit the "wall of sound" effect is what I particularly dislike about electrostatics.
 


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