Unusual Monitor Audios

[Geoff101]

I picked these up yesterday as they were only down the road. Paid too much as it turns out (see below) but interesting anyway:

https://ibb.co/1QL1939
https://ibb.co/7NfnV4g
https://ibb.co/Jjrsq8b
https://ibb.co/CH992VV

The model is MA 20, dating (according to marking on the bass driver) from around 1980. I've never heard of them. The internet has never heard of them. The people who remain at Monitor Audio have never heard of them. Their best suggestion was that they were likely some low volume series that Mo Iqbal created (something that apparently he made a habit of).

I could see from the photos that the mid ranges (Audax units) need re-foaming which isn't a problem but the first one I removed and tested is open circuit. Add to that, one of the bass driver voice coils is rubbing (I gave them a prod on collection but it would seem unfortunately prodded the side of the cone that pushes it clear!) and it's already looking like an non-economic repair.

Never mind.

Should be some pictures - can't get ImgBB to play at the moment...

[Geoff101]

https://i.ibb.co/c310NPN/MA20-1.jpg

https://i.ibb.co/h16BHfX/MA20-2.jpg

https://i.ibb.co/jk3rzqx/MA20-3.jpg

https://i.ibb.co/NyNNSWW/MA20-4.jpg

[Beobloke]

An interesting turn-up and they look very nice. Certainly too nice not to have a go at repairing!

[Geoff101]

I'll have to see if I can find a bass driver. I'm happy replacing surrounds but pulling spiders and voice coils out I've never tried. They look similar to those used in some of the R series.

[Lawrence001]

Could it be a Kef or Dalesford unit?

Any chance of a pic of the back of the bass driver?

Sent from my HRY-LX1 using Tapatalk

[Geoff101]

I don't recognise them as Kef - certainly was no obvious Bxxx or SPxxxx marking on the back like you usually get. Don't know about Dalesford.

The mids are Audax and have an integrated plastic enclosure to isolate them from the bass driver.

I'll whip one out later and get a picture. Wish I could work out why my pictures are not appearing in the text.

[Filterlab]

Wish I could work out why my pictures are not appearing in the text.
Sorted the tags for you mate. :)

[Geoff101]

Bass driver pictures as requested:

https://i.ibb.co/Mg21whR/MA20-5.jpg
https://i.ibb.co/rxsC4jB/MA20-6.jpg
https://i.ibb.co/0QRnzmp/MA20-7.jpg

[Geoff101]

Sorted the tags for you mate. :)

Thanks - I see what I was doing wrong now!

[technobear]

Just mount the rubbing bass driver the other way up for a while. It may fix itself.

[Filterlab]

Thanks - I see what I was doing wrong now!

Pleasure mate. Easy once you know how. :)

[Beobloke]

Just mount the rubbing bass driver the other way up for a while. It may fix itself.

^^^This^^^

And if you need any help with the mids, drop me a PM.

[Lawrence001]

Hard to tell if different from a Dalesford but they do look like very similar frames. I've not seen doped fabric or paper pulp bass drivers like these by them, but the picture in the link looks like it might be paper too.

https://images.app.goo.gl/eEctxMVqCiDJTRSTA

Sent from my HRY-LX1 using Tapatalk

[walpurgis]

Assuming that's an eight inch unit, apart from the smaller diameter dustcap, it looks just like the Mordaunt Short DSB 208 driver. Could be a version made and bought in just for this speaker.

Naim used one with no dustcap.

[system7]

I do't think any speaker companies made their own driver, but that Mordaunt Short driver rings a bell, but the terminals look different..

I like these sort of puzzles. Could be KEF B200 SP1014 or Dalesford D50-200. They look like the same chassis.

I think Dalesford were a bit cheaper, so popular. But the paper cone IS odd. MA used KEF SP1014 in the MA5 which was closed box.

The KEF was 210mm top to bottom. Easy enough to find the datasheet. Since the basses aren't in rebates, you could fit almost anything.

The mids look trickier, and maybe Beobloke has some ideas. But again you just need to find something that will fit. Presumably they have a little enclosure.

Well worth doing. Sort of project I like. Wilmslow Audio have some affordable replacement drivers. Falcon Acoustics have some Dalesford stuff.

[Lawrence001]

Looks a bit like these ones

Mordaunt-Short MS20 Speakers (Excellent Condition),
https://www.gumtree.com/p/for-sale/mordaunt-short-ms20-speakers-excellent-condition/1385536825

Sent from my HRY-LX1 using Tapatalk

[system7]

Those Mordaunt Shorts might do the job, Geoff. You could always contact the seller and ask for some measurements.

Wilmslow have a Monacor Midbass Driver that ought to fit at 210mm too:

https://www.wilmslowaudio.co.uk/monacor-sph-210-diameter210mm-654-p.asp

Any ideas on the mids? Some measurements would be useful if you need ideas.

[spendorman]

Think the bass unit chassis are KEF, special paper cone though.

[donmarrese]

The mid is an ELAC, fitted, to IMF's ASL 40 mk2's and others...I know cos I got one staring me in the eye right now...surround always need doing on these..
defo not a KEF bass unit, Poss MS thou this listing has a closeup thats quite close....
https://www.ebay.co.uk/itm/RAM-Bookshelf-Monitor-MkII-Speakers-Dalesford-Audax-Drivers-Classic-Vintage/264561983586?hash=item3d991f8062:g:LkkAAOSwjP9d7sZ M

[donmarrese]

Interesting read....
https://www.falconacoustics.co.uk/falcon-archive-links-history-tips/falcon-acoustics-archive/dalesford-speakers-drivers-datasheet.html

[Geoff101]

The mids say Audax on them.

[donmarrese]

The mids say Audax on them.Apologies, I'm looking at this which is quite similarhttps://uploads.tapatalk-cdn.com/20210205/f55794aee20f1d0e9d4f4ce27e97fd47.jpg

Sent from my ONEPLUS A6013 using Tapatalk

[Geoff101]

Those of you who called Dalesford for the bass driver might be into something looking at these:

https://www.ebay.co.uk/itm/RAM-Bookshelf-Monitor-MkII-Speakers-Dalesford-Audax-Drivers-Classic-Vintage-/264561983586?_trksid=p2349624.m46890.l49292