PMC clones

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
PMC seem to be the latest status symbol speakers. All the major recording studios use their professional monitors. I have heard some domestic models and they are very nice sounding if just lacking in bass. Funny that reviews laud their bass. They are super expensive when compared to other brands and this mystifies me.
Anyone tried to clone the older FB-1 series? I can buy some used for $1000 Cdn but these are almost 20 years old!
But their latest models are pretty attractive and sound pretty great. Do you think they know as much as Martin King does about TLs? They sure charge like they do.
I do see a lot on the used market though. I talked to one audio buff who has more invested in audio than I do in my house and he hated them. His friends also got rid of theirs for Ushers and top of line Revel speakers.
 
The first time I heard a pair of little nearfield PMCs in somebody's studio around the turn of the century I spent a half hour trying to find a non existent subwoofer.

So I have no idea why you think they are lacking in bass.
They did however skyrocket in price as they became more and more popular over the years.
 
Well I'm going to try to hear the FB-1. But with two different models of the twenty series in a showroom and in a buddy's house(where nothing sounds good unfortunately) they lacked bass. Image and detail was magical though.
I want to hear the bass that everyone raves about. I could stretch for the used FB-1 but never justify any newer models new or even used.
 
Member
Joined 2014
Paid Member
Are they installed as monitors in these places? Out on stands a proper monitor is hurting for bass.
In your face across a mixing board is a bit different(or in/on a wall facing said board). In a home I'd say on/in wall away from the corners. Or- eq below the baffle step out on stands.
Then, if you like them, consider building your own with fresh drivers for less money but more time. Sometimes these have had a hard life.
 
I have a pair of the original FB1's. The bass does go deep, but remember there are limits to what a 6" driver can do. It's a two-way, one driver for the base and mids. The tweeter is not the smoothest to my ears although it is very detailed sounding. Unfortunately, one of the tweeters has a dent in the cone. I may use this as an excuse to 'upgrade' to an FB1i by buying new tweeters and installing myself (along with XO). They are nice speakers.
 
Are they installed as monitors in these places? Out on stands a proper monitor is hurting for bass.
In your face across a mixing board is a bit different(or in/on a wall facing said board). In a home I'd say on/in wall away from the corners. Or- eq below the baffle step out on stands.
Then, if you like them, consider building your own with fresh drivers for less money but more time. Sometimes these have had a hard life.

Thanks for the advice. After building several lovely DIY speakers at a fraction of the price of similarly performing commercial speakers it is hard to think of buying something factory made. I guess it is my inferiority complex that makes me think they must be better and that they obviously know what they are doing. And look at all the accolades they get in the press ....
The modern PMC's I saw seemed reasonably placed in rooms. The showroom placement was a bit odd though. It was a long narrow room and the 2022 bookshelf speakers replaced halfway down the length of the room so about 10 feet from the back wall of a 20 foot long 8 foot wide room. Fantastic image side to side and depth wise. Not much bass. The floor stand 2024 were about 3 feet from the wall at one end of a similarly sized main floor of a house. But they were firing across the narrow distance of about 12 feet.
 
I have a pair of the original FB1's. The bass does go deep, but remember there are limits to what a 6" driver can do. It's a two-way, one driver for the base and mids. The tweeter is not the smoothest to my ears although it is very detailed sounding. Unfortunately, one of the tweeters has a dent in the cone. I may use this as an excuse to 'upgrade' to an FB1i by buying new tweeters and installing myself (along with XO). They are nice speakers.

The PMC site has a spare's page where drivers for all their speakers are available. The Tweeter for the FB-1 is the 12415 model on their page. There is a 12416 model and another numbered tweeter for the later several iterations of this speaker. Clearly these are in house inventory numbers. But nice to see that they support older models.
 
There is plausible arguement/point of view that "monitor' is not a descriptor of Quality.
(Although marketers push the notion)
Often far from it. Monitor speakers are for top of console placements and usually too near the mixer operator.
They are typically too small for for what any Audio Weenie would accept as Full Frequency reproductions.
Results are obvious in the preponderance of poorly balanced recordings as mixes are tailored to sound decent on the poor Studio monitors.. sitting in front of the operator's face.
Not saying V good small speakers don't exist.. because they certainly do.

But IMO rarely at the price points Studios will shell out for ;)
 
True transmission line vs. vented box

PMC seem to be the latest status symbol speakers. All the major recording studios use their professional monitors. I have heard some domestic models and they are very nice sounding if just lacking in bass. Funny that reviews laud their bass. They are super expensive when compared to other brands and this mystifies me.
Anyone tried to clone the older FB-1 series? I can buy some used for $1000 Cdn but these are almost 20 years old!
But their latest models are pretty attractive and sound pretty great. Do you think they know as much as Martin King does about TLs? They sure charge like they do.
I do see a lot on the used market though. I talked to one audio buff who has more invested in audio than I do in my house and he hated them. His friends also got rid of theirs for Ushers and top of line Revel speakers.

The PMC builds true transmission line cabinets based on the correct theory. The bass is natural, well tamed and extended quite low. If you are used to the bass reflex type boomy bass, a TL bass may sound missing to you.

Martin King calls his formulation TL, but they are in fact vented box with a resonant bass. The impedance line of MK TL has the bass reflex twin peaks, while the PMC impedance has either no peak or a small single peak as the true TL should.
 
The PMC builds true transmission line cabinets based on the correct theory. The bass is natural, well tamed and extended quite low. If you are used to the bass reflex type boomy bass, a TL bass may sound missing to you.

Martin King calls his formulation TL, but they are in fact vented box with a resonant bass. The impedance line of MK TL has the bass reflex twin peaks, while the PMC impedance has either no peak or a small single peak as the true TL should.

Interesting. Thank you.
 
Interesting. Thank you.
But might it be...?

There is nothing challenging about how TL or reflex speakers work. A reflex speaker is simply a Helmholtz resonator with the mass provided by the incompressible slug of air in the port and the spring by the air compressed within the cabinet. A transmission line uses the compressible resonances of a long pipe with the objective of letting the lowest resonance delayed by the pipe into the room to enhance the output from the driver and to use the material in the pipe to absorb the higher order resonances. The amount and type of damping material, varying the cross-section, placing the driver to minimise driving particular modes, the driver resonance, etc... play a role but it is still just a resonating pipe.

Since the physical processes are different they can be combined with, for example, an enclosure behind the driver and a long pipe. (I wanted to link to the Hi-Fi News article by Robert Fris describing his Daline design and how it works but my link is dead. Anyone?). I have not studied the small PMC speakers but the line looks a bit short to work well in the conventional manner.
 
There is plausible arguement/point of view that "monitor' is not a descriptor of Quality.
(Although marketers push the notion)
Often far from it. Monitor speakers are for top of console placements and usually too near the mixer operator.

Seems you are mistaking near-fields for monitors in general.

A monitor is any speaker of any size used in a studio ranging in size from tiny (Neumann KH120) to Tannoy Dreadnoughts or Quested HM415 (4way with quad 15" woofers) which would give some problems sitting on a meter bridge.
 
frugal-phile™
Joined 2001
Paid Member
Martin King calls his formulation TL, but they are in fact vented box with a resonant bass. The impedance line of MK TL has the bass reflex twin peaks, while the PMC impedance has either no peak or a small single peak as the true TL should.

Martin King carefully calls his lines quarter-wave resonators. It is the rest of us that call them TLs.

And if you are using the suppressed lower peak of an aperiodic enclosure as a measure of a TL…then none of the PMCs i found impedance curves for are TLs then.

You ar eone of those guys i run into from time-to-time that insist a TL should adhere to the title of Bailey’s 1st article, something the example in that paper did not adhere to.

dave
 

Attachments

  • PMC-DB1-imp.png
    PMC-DB1-imp.png
    49.5 KB · Views: 329
  • PMC-GB1-imp.png
    PMC-GB1-imp.png
    16.4 KB · Views: 330
  • PMC-twenty-imp.png
    PMC-twenty-imp.png
    26.9 KB · Views: 352
Although Dave doesn't need any help from me, I'd like to add in further contradiction of Keilau's comments that all vented boxes and all TLs, even Bailey's, are inherently 4th-order systems that will have twin impedance peaks, and it is possible to immensely reduce the magnitude of the lower-frequency peak, or eliminate it, by judicious use of stuffing, for instance. But that only eliminates all output from the line's terminus and its contribution to the bass response, making it more or less identical to a sealed box, so why bother making a TL in the first place? While I've never heard a PMC speaker, I've never been impressed with their alleged TL designs.
Paul

Martin King carefully calls his lines quarter-wave resonators. It is the rest of us that call them TLs.

And if you are using the suppressed lower peak of an aperiodic enclosure as a measure of a TL…then none of the PMCs i found impedance curves for are TLs then.

You ar eone of those guys i run into from time-to-time that insist a TL should adhere to the title of Bailey’s 1st article, something the example in that paper did not adhere to.

dave
 
The PMC builds true transmission line cabinets based on the correct theory.

Define 'correct theory'.

Martin King calls his formulation TL, but they are in fact vented box with a resonant bass.

Martin's alignment tables are actually for relatively well-damped lines.

The impedance line of MK TL has the bass reflex twin peaks, while the PMC impedance has either no peak or a small single peak as the true TL should.

As has been noted, all vented boxes have a characteristic double-saddle impedance curve; this is merely a matter of degree, and can be suppressed with damping. Nor is an MLTL, which you are presumably referring to, a bass reflex enclosure. A bass reflex enclosure assumes Helmholtz (cavity) resonance behaviour, i.e. a uniform internal air-particle density and no standing waves. An MLTL either deliberately generates and uses, or accounts for the presence of standing waves in a high aspect ratio pipe, using this to provide superior damping at tuning.
 
1st page attached
dave
Thanks. That is the article but the text is a bit too small to read. Do you by any chance have a link to the whole article on the web that works (mine is broken)?

After a ponder trying to recall what the article said I suspect it was probably more of a sealed box + pipe rather than a reflex + pipe as I suggested above. The resonant frequency of the Helmholtz resonator formed by the slug of air in the line and the volume behind the driver is likely to be below the passband of midwoofer. I am reasonbly sure it was discussed in the article even if I cannot recall what it said. One for the todo list.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.