PMC MB2S CLONE

[stargeezerme]

Hi

I'm planing to create my own MB2 clones, using Volt RV3143, Volt VM752, Vifa D27TG-35-06.

The cabinet will be constructed from a combination of 20mm and 35mm HDF board.

Im still at the early stage of design with this, and wondered if anyone else has tried the same project.

Thanks

 

[Scottmoose]

Probably, although you may have better luck posting in the multiway forum.

FWIW, I suspect you could get superior results with a redesigned line (I haven't modelled / back-engineered the PMC's line, but I would be rather surprised if that were not the case).

 

[stargeezerme]

Does anybody know how they've constructed the cabinet? it has a gap of around 1mm along all the edges........

 

[Bob Brines]

My guess is that the "gap" is purely cosmetic. When joining panels, particularly when one is veneer and the other is solid wood, a narrow dado is placed, usually on the veneer side. This makes it easier to transition from one material to the other.

Bob

 

[stargeezerme]

More drawings

 

[mystoudio]

SPEAKER PLANS FOR PMC BB5 AND XB3

HI... ANY SPEAKERS PLANS FOR PMC BB5 AND XB3 PLEASE

THANK YOU!!!

 

[Scottmoose]

Try the multiway forum, and removing Caps Lock.

FWIW, since this is a commercial product, I rather doubt there are any official plans uploaded, and on the offchance anybody has the exact schematics, the legality of posting them would at best be highly questionable, since they are presumably the IP of PMC Loudspeakers. Equally, to work as PMC intended, you would need to use exactly the same drivers, crossover & construction materials as they do, in the latter case most obviously damping. PMC make their own foam or have a propriety type made for them, so you would need to somehow ascertain the precise damping properties of this and either get hold of some via unofficial means, or adjust the quantities, densities & locations of a more easily available type to ~mimic the behaviour of their own damping.

With all that said, there is nothing particularly novel about PMC's transmission line designs & you could design something similar or possibly superior easily enough.

 

[xrk971]

As Scottmoose said, Why would anyone have plans of a commercial product? Based on sketch above, it would not be hard to design a transmission line from scratch. Again, this is a multiway, we would only deal with a full range TL here anyhow. Also, given dimensions above, you can reverse engineer it if you wanted to.

 

[stargeezerme]

Try the multiway forum, and removing Caps Lock.

FWIW, since this is a commercial product, I rather doubt there are any official plans uploaded, and on the offchance anybody has the exact schematics, the legality of posting them would at best be highly questionable, since they are presumably the IP of PMC Loudspeakers. Equally, to work as PMC intended, you would need to use exactly the same drivers, crossover & construction materials as they do, in the latter case most obviously damping. PMC make their own foam or have a propriety type made for them, so you would need to somehow ascertain the precise damping properties of this and either get hold of some via unofficial means, or adjust the quantities, densities & locations of a more easily available type to ~mimic the behaviour of their own damping.

With all that said, there is nothing particularly novel about PMC's transmission line designs & you could design something similar or possibly superior easily enough.

What he said above, spot on. Though im not too fussed about the copyright issue, because I believe PMC will know how hard it will be to replicate their products.

The internal design of the MB2 is still a bit of a mystery because i have found no information on it. I do however have the design of the BB5's because it was a back ground image in their MB2 / BB5 active brochure.

 

[delapoer]

It would appear that either (or both) of PMC and Volt didn't mind making mid-range domes to almost the same design as the ATC ones when ATC stopped supplying them with their drivers! Maybe there was some legal agreement, or no patent/copyright, but the PMC versions are very similar to look at!

 

[bjorno]

Hi,

FYI A thread few years ago dealing with a similar design questions:

http://www.diyaudio.com/forums/multi-way/108336-transmission-line-question-3.html

b

 

[delapoer]

Thanks a lot Bjorno. That thread has evolved slightly, do you have anything to add to it?

 

[tiefbassuebertr]

I have heard the genuine model of this brand last weekend. Sound quality was for me nearly perfect in all respects.
I am looking for test reviews and diagrams for frequency responses, THD spectrum, impedances and so on.
Who can post this? Additional I want to know, whether the midrange dome it is a custom made version or a free available version like Volt's VM752 or
ATC’s SM75-150 ?
Thank you for your efforts

BTW - why is this thread sorted by the file "full range" instead "multiway" ?
Maybe due it's sound character like a point source ?

 

[Scottmoose]

I've heard them & thought that the sound quality was certainly acceptable but far from perfect in all respects. Be that as it may however:

Probably nobody. I don't think any magazine that takes measurements has reviewed them. Not in English anyway, and I haven't seen any in other languages either, although I haven't been looking of course, so you're probably better placed to say on that score as you're interested in them.

Custom driver as far as I know, designed & made to their spec. If fallible memory serves, they assemble the mid-dome themselves. To the best of my knowledge all PMC drivers are custom, although the extent of differences from regular production units by OEM suppliers likely varies.

I doubt it. More likely it was because the OP saw the term 'full range' on the forum and didn't realise it was a reference to single / fullrange / wideband drivers, which would technically be the more accurate description. Fairly common occurrence & usually shunted over to the multiway forum by the mods, but the occasional one slips through the net.

 

[Twinky]

I wonder how the PMC would compare to this:
WA TL12- Volt midrange

 

[darkmatter]

Great find

What he said above, spot on. Though im not too fussed about the copyright issue, because I believe PMC will know how hard it will be to replicate their products.

The internal design of the MB2 is still a bit of a mystery because i have found no information on it. I do however have the design of the BB5's because it was a back ground image in their MB2 / BB5 active brochure.

Fascinating and an excellent observation.

I wonder what grade cellular foam fill PMC use for their ATL in the BB5?

 

[darkmatter]

Volt VM752 Bandpas filter

Pleased I found this thread rather than starting another, I am going to try and work on a design influenced by the BB5 but not a clone.

Does anyone have a bandpass filter design for the Volt VM752 mid I could experiment with?

Many thanks,

Simon

 

[delapoer]

I believe that you can't buy these drivers from PMC or from anyone else but they look very similar to the Volt dome mids and since PMC source some of their bass drivers from Volt (the Radials which PMC have modified slightly (by doping the cone I believe to make it their part) I wouldn't mind betting that Volt were involved if they aren't now. One of the giveaways is the four bolt fixing on both Volt and PMC to clamp the driver together, the ATC has three. Also the Volt and PMC domes can easily be replaced whereas I believe the ATC needs more extensive rebuilding. I have a pair of the PMC domes and I think they are fantastic.


PMC

I have heard the genuine model of this brand last weekend. Sound quality was for me nearly perfect in all respects.
I am looking for test reviews and diagrams for frequency responses, THD spectrum, impedances and so on.
Who can post this? Additional I want to know, whether the midrange dome it is a custom made version or a free available version like Volt's VM752 or
ATC’s SM75-150 ?
Thank you for your efforts

BTW - why is this thread sorted by the file "full range" instead "multiway" ?
Maybe due it's sound character like a point source ?

 

[delapoer]

I know that at one time PMC were doing the doping of the domes themselves, in that case I think they would probably be doing the whole assembly process themselves. That doesn't mean that they weren't buying in parts from other makers though, Volt would seem to be the obvious source. The big Radial bass drivers are almost certainly sourced from Volt, probably with slight modification to make them proprietary PMC parts, I think that they also use slightly modified Scanspeak HF drivers too.

I've heard them & thought that the sound quality was certainly acceptable but far from perfect in all respects. Be that as it may however:

Probably nobody. I don't think any magazine that takes measurements has reviewed them. Not in English anyway, and I haven't seen any in other languages either, although I haven't been looking of course, so you're probably better placed to say on that score as you're interested in them.

Custom driver as far as I know, designed & made to their spec. If fallible memory serves, they assemble the mid-dome themselves. To the best of my knowledge all PMC drivers are custom, although the extent of differences from regular production units by OEM suppliers likely varies.

I doubt it. More likely it was because the OP saw the term 'full range' on the forum and didn't realise it was a reference to single / fullrange / wideband drivers, which would technically be the more accurate description. Fairly common occurrence & usually shunted over to the multiway forum by the mods, but the occasional one slips through the net.

 

[delapoer]

It looks as though it is an attempt at making something very much like a PMC speaker. I'd imagine that it would be very good (with the right crossover but that's another story) but probably fall short of the real PMC (which would cost a huge amount more)

I wonder how the PMC would compare to this:
WA TL12- Volt midrange