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SD Acoustics SD1 driver repair / replacement

Discussion in 'classic' started by stephen_cowslip, Dec 22, 2022.

  1. stephen_cowslip

    stephen_cowslip pfm Member

    Afternoon, all.

    I've recently acquired a rather lovely pair of SD Acoustics SD1 speakers which are in fantastic shape, bar the drivers.

    The foam on both mids and woofers has perished.

    Does anyone know how I would go about getting the drivers either repaired or replaced?

    I think Falcon Audio used to stock parts but sadly no more.

    Thanks in advance, as usual.
  2. Beobloke

    Beobloke pfm Member

    You used to be able to buy the flat surrounds for these but I cannot for the life of me remember where. I'll see if I can dig up the information.
    stephen_cowslip likes this.
  3. sp25

    sp25 pfm Member

    Which drivers do you have? I have some used spares
  4. stephen_cowslip

    stephen_cowslip pfm Member

    Thanks @sp25 for the reply.

    I'll check when I get back from work. I collected them this morning so not had a chance to give them a proper once-over.
  5. stephen_cowslip

    stephen_cowslip pfm Member

    @sp25 I took a few photos. I wonder if you can tell which drivers were used without me taking them out.

    Seems some wires are cut on the crossover which seems a little strange..








  6. Tony L

    Tony L Administrator


    I’ve shifted this into the classic room, it is far too sensible for the audio room.

    PS Very interesting speakers, never heard a pair, but they have a reputation of being very good.
  7. stephen_cowslip

    stephen_cowslip pfm Member

    Thanks, @Tony L

    I was in two minds where to post.

    Yup I'm absolutely committed to getting these back up to working order, if possible.
  8. hp1

    hp1 pfm Member

    Perhaps the previous owner wanted to keep using them so disconnected the bass units to prevent damage to the voice coils as the roll surrounds broke down.
    stephen_cowslip likes this.
  9. Tony L

    Tony L Administrator

    Do you have a multimeter? If so the first thing to do is to measure the drivers at their individual terminals. There should be some Ohms. If not you are in trouble. If the voice coils are intact re-foaming should not present a huge issue. Frank (@cooky1257) will likely be able to advise, or maybe even do it for you at a decent price if you don’t feel like tackling them yourself. I’d be very reluctant indeed to replace drivers unless a) absolutely necessary, or b) you really know what you are doing. It is incredibly easy to screw up a good speaker with a close but not quite right driver.
    stephen_cowslip and cooky1257 like this.
  10. Ayya Khema

    Ayya Khema pfm Member

    You sir are a lucky men
    Amazing loudspeakers

    the mid is a audax pr170mo coated
    Should be easy to refoam or you can buy a new pair
  11. Craig B

    Craig B Re:trophile

    I'd have a closer look at those snipped wires. Could just be jumpers between the LH and middle pair of terminals, meaning that a previous owner may have been passively bi-amping these, i.e. one amp on bass, another on mid and tweeter.

    The bass drive looks like an Audax PR240MO, perhaps with some doping applied. If the coils are shot, both Wilmslow Audio and Falcon Acoustics should be able to advise re: substitutes.
  12. stephen_cowslip

    stephen_cowslip pfm Member

    No multimeter, @Tony L

    If I'm being 100% honest, I'm probably only qualified enough to remove / replace the drivers!

    I'll get some more detailed photos of the crossovers tonight but I think @Craig B could be correct that the previous only was bi-amping and cut the junction wires.

    Looks like I've got plenty of options. I suppose first call is to see how suitable the drivers are for re-foaming and then take it from there.

    I will drop @cooky1257 a PM and see where it takes me.
    cooky1257 likes this.
  13. Ian G

    Ian G pfm Member

    I can lend you one if required (multi meter)
    stephen_cowslip likes this.
  14. Tony L

    Tony L Administrator

    I’d definitely buy one. They are hugely useful things to have knocking around for everything from checking batteries, turntable earthing, speakers, cables, arm wiring etc etc long before you get to proper electronics. Certainly don’t think they are only relevant to those doing in-depth electronic service. Every home should have one IMHO.

    Which one is however a minefield. There is a massive range from really cheap no-name Chinese crap that will likely only last a month or two and would fail electrical safety regs for about a fiver right through to real high-end Fluke, Tektronics etc at many £hundreds or more. My starting recommendation would be to at least stick to a recognisable brand, e.g. here’s a decently spec’d meter from Amazon Commercial that would do everything you need for £20. The key is it is auto-ranging, so easy to use, has a continuity beeper (very useful), has the combination of a well known brand (Amazon) and has clearly stated CAT ratings, so should be safe on mains voltage. Amazon wouldn’t want the legal implications of selling something that would blow your hand off if you connected it to the mains. It is a ridiculously high spec for the money so I’m sure some corners have been cut somewhere, but it will certainly do what you need to check voice coils, continuity etc.
  15. ff1d1l

    ff1d1l pfm Member

    PM Frank @cooky1257 and ask him if he'd please re foam the drivers - he'll do an excellent job.

    Re connect the cut wires temporarily, bare the ends, then just twist them together. Reinstall the refoamed drivers, connect and see what sort of sound comes out.
    If theres a problem, someone on here will surely look at the crossover for you.
    If the wires were cut to facilitate bi wiring/bi amping, or even triwiring/tri amping, and you have access to a pair, or trio of identical high quality power amps, you might give it a whirl. I run my system in this mode and find the SQ uplift well worthwhile.
    Good luck, they look to be lovely speakers in great condition, and are the desirable ribbon tweetered variant. I don't know what your other speakers are under the dust covers, but I'm sure sorted out, and maybe even tri wired(!) these would give most modern speakers a run for their money.
    cooky1257 likes this.
  16. cooky1257

    cooky1257 pfm Member

    Last edited: Dec 24, 2022
    Johnjo and ff1d1l like this.
  17. stephen_cowslip

    stephen_cowslip pfm Member

    @cooky1257 just on my way out for a Christmas Eve breakfast but will ping you a message when I get back.

    cooky1257 likes this.
  18. cooky1257

    cooky1257 pfm Member

    Thanks for the recommendation guys.
    ff1d1l likes this.
  19. Craig B

    Craig B Re:trophile

    Came across that yesterday, hence my guess that the snipped wires were links between the terminals. Most of the back side photos of SD1 online show red and black wire links between the terminal posts on the outside.

    Apparently this was hand drawn by Steen Falck Doessing, president and chief designer of SD Acoustics.
  20. donmarrese

    donmarrese Member

    I had a pair of these, had mine done by Dagenham Dave from Rainham, did bass and miss...he purchased generic surrounds with the correct dimensions. Ideology/design of the SD1 is very appealing, but soon sold them on as they didn't deliver what I wanted from my system. Found MA 3's to surpass them easily

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