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PMC Twenty5.21/22/25's - any users?


It is not only believable it has been pretty much the standard for high quality, high fidelity speakers for the last decade or two in both commercial and DIY speakers. It is achieved by using an active crossover and setting it up during speaker assembly to compensate for the slight variations in the mechanical properties of the drivers. That is, each speaker is individually tuned to meet a target response (flat in this case) to within a fraction of dB typically. As the speakers age the process can be repeated to compensate for any slight drift in mechanical properties. Any modern expensive speaker that is not designed in this way is declaring a disinterest in high quality engineering and high fidelity performance (of course other factors like off-axis behaviour, adequate clean SPL,... are relevant as well).

It can sometimes be difficult to comprehend just how irrelevant high fidelity and good quality engineering has become in the weird marketing dominated luxury goods sector that home audio has become. For the price, domestic PMC speakers are poor-to-modest when judged against such criteria but such criteria are not highly weighted but purchasers of PMC products. And why should they be if PMC products provide what the purchasers actually want from their speakers?

The "Preaching Tolerances" section near the end of this review gives some details on the tolerances achieved at the factory in Ireland. A modern mass produced speaker affordable to enthusiasts that significantly weights good engineering and high fidelity should meet it's target on-axis response (probably flat but not necessarily depending on off-axis behaviour and/or compensating for stereo issues and/or room influences) to within +/- 0.5 dB. The days of +/- 3 dB are long gone except of course in the audiophile world!
 
I’ve had several pairs of pmc from gb1 , gb1i and twenty 20.23 and they’ve never stayed that long in my room. Seems to be some discord between bass and treble and midrange is recessed for vocals. My favourite brand is Atc and now running dynaudio which work really well especially at low vols where most of my listening is when working at home
 
I'm currently listening to TB1's which would appear, from what I read here, to have the same signature sound of other models from the brand.
I would concur with the recessed mid range giving a milder impression of music. On the plus side is the fuller bass and lower mid range giving a bigger sound for their size compared to similar sized speakers I have used.

They are reassuringly constructed and happier playing at high levels with a meaty amp.

Looks wise they would look more at home in a studio as they not as pretty as some in a domestic setting.

Mixed feelings I guess, to sum up.
 
My experience is that PMC speakers are cold, steely and sterile with zero communicative emotion. Music is flat, lifeless, deflated, empty and sad. Once again, to be fair and give PMC some credit, I would say that the ability to "engineer out" the communicative musicality of a loudspeaker is indeed a form of technical know-how.
Brgds.

What would you classify as a good speaker?

My experience is the opposite, they are fairly natural sounding (see below), at least the three ways (i've not heard any of their smaller two way speakers). I agree about the new price, but some good deals can be had second hand. PMC have details of every speaker they made so it's possible to service them and replace drivers etc if needed.

 
I know quite a few well regarded recording and mastering studios use PMC speakers for their monitoring ;)
So they probably know a bit about what they are doing.

As for the price , yes they are expensive yes but after having had the MB2se on home dem i had no hesitation in buying them. The best speaker i've ever heard and my final speaker . Cherry on the top is a 20 year guarantee.... many happy years listening to look forward too.
 
It is not only believable it has been pretty much the standard for high quality, high fidelity speakers for the last decade or two in both commercial and DIY speakers. It is achieved by using an active crossover and setting it up during speaker assembly to compensate for the slight variations in the mechanical properties of the drivers. That is, each speaker is individually tuned to meet a target response (flat in this case) to within a fraction of dB typically. As the speakers age the process can be repeated to compensate for any slight drift in mechanical properties. Any modern expensive speaker that is not designed in this way is declaring a disinterest in high quality engineering and high fidelity performance (of course other factors like off-axis behaviour, adequate clean SPL,... are relevant as well).

It can sometimes be difficult to comprehend just how irrelevant high fidelity and good quality engineering has become in the weird marketing dominated luxury goods sector that home audio has become. For the price, domestic PMC speakers are poor-to-modest when judged against such criteria but such criteria are not highly weighted but purchasers of PMC products. And why should they be if PMC products provide what the purchasers actually want from their speakers?

The "Preaching Tolerances" section near the end of this review gives some details on the tolerances achieved at the factory in Ireland. A modern mass produced speaker affordable to enthusiasts that significantly weights good engineering and high fidelity should meet it's target on-axis response (probably flat but not necessarily depending on off-axis behaviour and/or compensating for stereo issues and/or room influences) to within +/- 0.5 dB. The days of +/- 3 dB are long gone except of course in the audiophile world!

I would love to hear this achievement. Flat to 10Hz from a 97 litre enclosure is an incredible achievement. Will watch out for this product at shows etc.

(p.s. FYI, I run PMC Twenty.26 with a Linn Exakt phase correcting active digital crossover, so I know some of what's possible and some of what isn't)
 
A lot of hate for PMC here..to me (in my room with my equipment and my own cloth ears) the PMC 25.22 have been the best modern speakers in a long while. I had Dynaudio special 40 right before these and I was only left with disbelief what special ppl heard in these because they were dull and uninvolving despite the raving reviews - changed them back to my old Proac 1sc in a week. I have also owned Dyn C1 which received high praise and same thing - dull and did not grab me at all - Special 25 different story but did not receive such great reviews as the C1. Anyway I couldn't give a rats a$$ if a speaker I hear and I know I like gets bad figures in some tests because I don't listen to those figures but I know when I hear music reproduced in a way that gets under my skin and my foot tapping and that's what matters and rest is just irrelevant. But then again I also love my tube amp which probably doesn't measure very well. Each to their own I guess.
 
I would love to hear this achievement. Flat to 10Hz from a 97 litre enclosure is an incredible achievement. Will watch out for this product at shows etc.

(p.s. FYI, I run PMC Twenty.26 with a Linn Exakt phase correcting active digital crossover, so I know some of what's possible and some of what isn't)

Do you really not know what equalisation is? You too could make the on-axis response of your speakers flat to 10 Hz possibly for no cost if you have a decent microphone, sound card, can run an audio signal through your PC to do the equalisation, know how to generate the relevant filter coefficients and if the doubtful loading of your bass driver is minimum phase and invertible (probably but better to check). I am curious if other audiophiles reading this thread consider it remarkable that the on-axis response of a reasonably well behaved speaker can be equalised to be flat to within a fraction of a dB. If so, it just goes to reinforce my point earlier about how detached from engineering reality much of home audio has become.

Unlike PMC, Neumann (previously Klein and Hummel) don't sell into the consumer/home audio market and instead target those that require well engineered high fidelity speaker as a tool to do a job. They likely allocate no resources at all for marketing to the home audio sector so don't expect to see them in home audio shows, shops or publications. The parent company Sennheiser has just sold off it's consumer audio division reducing even further the likelihood of any move towards the home audio sector.

Having attended a few home audio shows over the last few years, chatted to attendees and observed the comments on forums like this I think it is fair to say that many enthusiastic audiophiles have little interest in well engineered high fidelity speakers. It is not that they are disliked but more that they are ordinary/neutral rather than attractive. Nothing wrong of course with having different interests/objectives but failing to master the basics does leave one more vulnerable to being sold poor value products which over time one begins to recognise as such.
 
Do you really not know what equalisation is? You too could make the on-axis response of your speakers flat to 10 Hz possibly for no cost if you have a decent microphone, sound card, can run an audio signal through your PC to do the equalisation, know how to generate the relevant filter coefficients and if the doubtful loading of your bass driver is minimum phase and invertible (probably but better to check). I am curious if other audiophiles reading this thread consider it remarkable that the on-axis response of a reasonably well behaved speaker can be equalised to be flat to within a fraction of a dB. If so, it just goes to reinforce my point earlier about how detached from engineering reality much of home audio has become.

Unlike PMC, Neumann (previously Klein and Hummel) don't sell into the consumer/home audio market and instead target those that require well engineered high fidelity speaker as a tool to do a job. They likely allocate no resources at all for marketing to the home audio sector so don't expect to see them in home audio shows, shops or publications. The parent company Sennheiser has just sold off it's consumer audio division reducing even further the likelihood of any move towards the home audio sector.

Having attended a few home audio shows over the last few years, chatted to attendees and observed the comments on forums like this I think it is fair to say that many enthusiastic audiophiles have little interest in well engineered high fidelity speakers. It is not that they are disliked but more that they are ordinary/neutral rather than attractive. Nothing wrong of course with having different interests/objectives but failing to master the basics does leave one more vulnerable to being sold poor value products which over time one begins to recognise as such.

I used TacT's ATB room correction for quite a while, without carefully engineering the target curve from flat (you couldn't fill in the nulls so it was never really flat) to a slope down into the high frequencies it was un-listenable on 50% of music, i'm not sure about you but i want to listen to more music not less!
 
Do you really not know what equalisation is? You too could make the on-axis response of your speakers flat to 10 Hz possibly for no cost if you have a decent microphone, sound card, can run an audio signal through your PC to do the equalisation, know how to generate the relevant filter coefficients and if the doubtful loading of your bass driver is minimum phase and invertible (probably but better to check). I am curious if other audiophiles reading this thread consider it remarkable that the on-axis response of a reasonably well behaved speaker can be equalised to be flat to within a fraction of a dB. If so, it just goes to reinforce my point earlier about how detached from engineering reality much of home audio has become.

Unlike PMC, Neumann (previously Klein and Hummel) don't sell into the consumer/home audio market and instead target those that require well engineered high fidelity speaker as a tool to do a job. They likely allocate no resources at all for marketing to the home audio sector so don't expect to see them in home audio shows, shops or publications. The parent company Sennheiser has just sold off it's consumer audio division reducing even further the likelihood of any move towards the home audio sector.

Having attended a few home audio shows over the last few years, chatted to attendees and observed the comments on forums like this I think it is fair to say that many enthusiastic audiophiles have little interest in well engineered high fidelity speakers. It is not that they are disliked but more that they are ordinary/neutral rather than attractive. Nothing wrong of course with having different interests/objectives but failing to master the basics does leave one more vulnerable to being sold poor value products which over time one begins to recognise as such.

Interesting that you jump to personal insults with no basis and no understanding of what it takes to design filters for Exakt, but ho-hum.

I'm interested in the physics of how they appear to have made this possible and practical when so many can't.

Like I said, I'd like to hear this speaker as I'm fascinated to find out what it sounds like to achieve what they claim to have achieved.

Brand bashing doesn't appeal to me.
 
I'm interested in the physics of how they appear to have made this possible and practical when so many can't.

I think you are going to have to spell out what you think is remarkable about the speaker. It is among the handful of well engineered high fidelity speakers one could use as reference main speaker in the home but there are others from Genelec, JBL and perhaps one or two other manufacturers that are fairly similar. There is nothing remarkable about the speaker except, arguably, that it uses current engineering technology to create a high fidelity speaker for reasonable cost with significantly less consideration given to conflicting criteria than would be the case with typical home audio speakers. It uses the smallest cone area that can reproduce low frequency transients cleanly at typical listening distances in a home, waveguides to control the directivity above the Schroeder frequency (although it leans more towards studio use than home use in being constant), active crossovers with suitably sized power amplifiers for each driver, non-wooden cast cabinet, etc...

Like I said, I'd like to hear this speaker as I'm fascinated to find out what it sounds like to achieve what they claim to have achieved.

But they aren't claiming to have achieved anything remarkable beyond the competent application of current technology. Unlike home speakers the specification is fairly complete because it is sold primarily as a tool to do the job of reproducing sound accurately. For example, some claims from the specification:

Free field frequency response ±3 dB 26 Hz … 22 kHz

Reproduction accuracy between 100 Hz and 10 kHz: 100%, 80%, 50% of loudspeakers produced ±0.78; ±0.36; ±0.22 dB

Max. short term SPL with IEC-weighted noise (IEC 60268-5) at 1 m, in typical listening conditions 109 dB(C) SPL

Max. short term SPL with music material at 2.3 m in typical listening conditions (pair / full range) 103 dB(C) SPL

Plus a bunch more similarly meaningful information for those that understand the basic technical requirements of a speaker to accurately reproduce a music signal (which is of course the target market for the speakers and not audiophile enthusiasts).

This represents pretty much the best that can be done commercially at the price but doesn't seem remarkable in any way that I can see. Note these are solid hard numbers which checkout with 3rd parties like their customers who will generally have the technical ability to test and can be expected to take action if the specification they purchased is not met. It is quite different to the home audiophile sector where hard numbers are few and often vague (e.g. tolerances missing) with marketing used to promote the perception of extraordinary performance among technically uninformed consumers. The contrast with primarily marketing-lead companies like PMC and primarily engineering-lead companies like Neumann is striking despite the superficial perception that they are both "pro" companies.

Brand bashing doesn't appeal to me.

One is tempted to say that people in glass houses shouldn't throw stones but, of course, people already are throwing stones at your glass house so why not throw some back?
 
Re the Neumann KH420 loudspeakers
But they aren't claiming to have achieved anything remarkable beyond the competent application of current technology. Unlike home speakers the specification is fairly complete because it is sold primarily as a tool to do the job of reproducing sound accurately. ...
Yes, I'm sure that's right. And I'm very much a fan of quality engineering. And quality engineering is part of what pleases me about a product. The KH420s look very interesting indeed. I might try them if I were interested in new loudspeakers today.

But in my world view the definition of quality includes "fitness for purpose". That "for purpose" is important to me. It seems clear that for the purpose of enjoying music a lot of people posting here achieve that purpose without the clear technical prowess of the KH420s. But if anyone enjoys them for their technical excellence that's good too.

My own experience is that once quality is sufficient to not detract from my enjoyment of the music (that's my purpose), going further doesn't achieve more. For example, I have tried equalizing the frequency response of my loudspeakers to better than I can get with careful positioning. The system sounded different, but taking a step back from the "better technology" argument I found I wasn't enjoying the music any more. So I no longer equalize. To me it's like chasing record SNR measurement in DACs: good enough is good enough and better is no better to me in practice. Although, once again, there's nothing wrong if it pleases someone to pursue that avenue as part of the way they enjoy their hobby.

I like some aspects of PMC's current domestic loudspeaker range but brief listening sessions tell me other aspects may detract from what I like. I was more detailed in a previous post. But PMC is successful so enough customers seem to find them good enough for their purposes. Discussing how PMC's domestic loudspeakers sound to me seems OK, but I would hesitate to argue against anyone else's idea of what's fit for their purposes rather than mine. As I think you have written or implied, people do have widely varying tastes.
 
Don’t wish to divert this thread away from the original topic, but I’d like to add my impressions of the Neumann 420. It is is an uncoloured speaker that gives a very neutral representation of the recording, as a true studio monitor should. However, unlike some BBC inspired monitors it does not lack dynamic range or bass. It will play loud, really loud, without distorting with solid bass, 30 Hz to high 20s I’d estimate, but certainly not down to 10 Hz. I liked the 420 a lot and in some ways prefer it to the Kii 3. Having said that, it is quite possible that those seeking speakers with ‘character’ to suit their tastes might not care for this type of sound.

A technical appraisal can be read here:

https://en-de.neumann.com/product_files/6506/download

I’ve never heard the PMC Twenty's, and don’t know how similar the Fact and Twenty series are to each other, but this review of the Fact 8. in stereophile was a turn off- note the boosted highs:

https://www.stereophile.com/content/pmc-fact8-signature-loudspeaker-measurements
 
Don’t wish to divert this thread away from the original topic,
I think all the posts have been a diversion from that, since the question was are there any users of the Twenty5 series? :) So far, so useless. We don't even know what 'h.g.' actually listens to music on.
 
Sunbeamgls, as you design Exakt filters for PMC speakers, you must have measured these speakers in stock form. Do the 25 series exhibit a treble hump?
 
Only heard PMC Fact something or other floorstanders briefly at a shop and they sounded ‘ok’ but I certainly remember the time when my uncle and cousin returned from a hifi show years ago (Bristol I think) and laughing about how terrible the PMC speakers sounded.
 


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