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PMC Twenty.21 Bookshelf Speaker Review
- Thread starter amirm
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Andreas007
Active Member
Listened to Fact 8 at High End Munich. They are clearly sounded to impress during the first minutes. In fact (german humor...) my first impression was not bad at all. But then you realize there is something very different compared to other speakers: Too much highs. Other speaker but the experienced sound profile is now confirmed by Amir, thanks.
Transmission lines can work well but they have to be much bigger than this. They offer bass roll off somewhere between sealed and ported enclosures. In reality, transmission line, ported and back loaded horns are all on a continuum, with all designs showing some of their characteristics, while one tends to dominate. For a transmission line to have the same bass extension as a ported enclosure it will tend to be quite a bit bigger. Small transmission lines don't work.
The term transmission line is not really descriptive of how they work - the term quarter wavelength line is a bit more accurate. How long does a transmission line need to be? Take the wavelength you want bass down to and divide by four. You can get away with a bit shorter than that, but that is the basic idea. 40 hz is like 28 feet / 4 = 7 foot long line.
I don't know what makes these 'advanced' transmission lines; they seem to offer none of the benefits and all of the disadvantages.
Full phase Vs frequency. I have a vague memory of an Alan Shaw rant about transmission lines not working because they change phase and at some frequencies cancel the main driver output causing lean bass.
Archsam
Senior Member
An ATC SCM19 is here for review.
This will be very interesting..... I auditioned their smaller brother SCM11 a few years ago (my reason was actually to try out the ATC SIA2-150 integrated amp). My subjective impression that day was not so good, I did not find the combination appealing to my ears.
I then tried the ATC speakers with a Bel Canto pre-power combo (can't remember the model), a Unison Research Nuovo, and a Devialet 140. None of them sounded particularly good. The salesperson was so excited to demonstrate the Devialet (it was his idea to try out, not mine), and it was the worse sounding amp I heard that day.
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True, the recently booming headphone business is an even bigger mess compared to loudspeakers, but that's not really an excuse for either.
Also my experience is that many of such headphone gear fans are rather young and listening so much to them that they have "lost" the contact to natural voicing.
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And most important they have more continuous directivity and lower distortions so they can be EQed easily to something significantly better.
Thanks to the measurement efforts of sound and recording as well as stereophile this wasn't a big surprise... but I still think it's insane that they think asking 2k for this is reasonable. And worse yet - a lot of people probably buy this. That being said, one can get used to almost anything, so I'm sure the owners of these speakers are very happy.
tuga
Major Contributor
OMG.The poor guys who use this to mix or master a recording, it must sound bass shy and dull.
Or is this "monitor" speaker broken? Do you have a second one to remeasure distortion?
Not that the Pro-series is likely to be much better (JA measured the IB-1S here) but why would any pro worthy of his badge mix with a domestic-series toy-sized speakers anyway?
PMC's domestic speakers are some of the worst sounding speakers I have ever heard. My local dealer stocks them (or did).
Not only that, they are ridiculously expensive for what they are and astonishingly innefficient, the Fact 8 I listened to in a demo room needed about 20dB more level on the amp than I need in a much bigger room with the same amp on my speakers.
I habe never heard their pro monitors though, the ones I have seen are very different to the domestic line.
Not only that, they are ridiculously expensive for what they are and astonishingly innefficient, the Fact 8 I listened to in a demo room needed about 20dB more level on the amp than I need in a much bigger room with the same amp on my speakers.
I habe never heard their pro monitors though, the ones I have seen are very different to the domestic line.
Wait till he finally gets a panel speaker to measure...
I wonder how the Klippel motion software will handle a 48 inch tall mid-tweeter?
Fluffy
Addicted to Fun and Learning
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I remember when I went to buy my first serious speakers, I had a listening session at a store. As I was auditioning some low cost powered speakers, the employee asked me want I'm looking for, and I answered somewhat naively "something that sounds crystal clear". He snickered and said that for that I need to spend thousands of dollars on PMC speakers. Well, I guess it's good that I didn't listen to him then.
Also, I wanted to add that Amir is truly the mythbuster of the audio world!
Also, I wanted to add that Amir is truly the mythbuster of the audio world!
tuga
Major Contributor
Fact 12
Twenty.26
Twenty.26
tuga
Major Contributor
The midrange dome break up resonance is alive and kicking.
OP
- Thread Starter
- #77
Let me attempt to defend... or rather... rationalize this price/performance
- PMC was formed in 1990 by Peter Thomas (previously of the BBC) and Adrian Loader (previously of FWO Bauch, an audio distributor)
- PMC sold studio monitors to BBC
These speakers were probably born out of requirements back then, and probably had good performance back then. And hence also commanded good price back then.
However speaker technology progressed. By early 2000s we already have brands moving away from boxy edges, and even a few experimenting with rudimentary waveguides. Oh and ports became the standard.
But consider the situation. We have a big studio with a long history (BBC and etc.) using speakers with a long history. (PMC, and even Rogers...) It is just not possible to tell people to change speakers, especially when the newer speakers sound so different.
What would a person in this situation logically do? Reject the newer sounds as inferior products, embrace the "British sound", and give an Emmy Award, of course.
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Been waiting for one of these. It gives me the fear though, as an ATC owner.An ATC SCM19 is here for review.
I'm not at all surprised with the PMC's performance. I demoed a pair of their floorstanders against KEF R7s and ATC SCM40s, and strongly recall feeling the PMC's upper range sounded detached and artificial. It's striking to see that impression borne out so clearly in measurements.
I did, however, come away with the ATCs, and feel Amir's SCM19 measurements might reveal less than SOTA performance...
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