I appreciate the kind words regarding my health situation. I don't really like to talk about it as I'm already too overwhelmed with it all. Unfortunately its a terminal illness that can't be treated without causing other severe symptoms my body won't tolerate. I've been in bed now most of the time and haven't been able to leave the house for over 2 months. I'm lucky to have some pain relief but once that isn't enough anymore to let me sleep, it will be over for me.
Our thoughts are very much with you right now. You have been a shining light for us.
Thanks guys, I really appreciate that.
Let's try to keep this thread on track.
Let's try to keep this thread on track.
Not sure if this dome mid has been discussed in this thread? Pretty flat response in it's passband, nice waterfall, and reasonable price......https://www.visaton.de/en/products/drivers/dome-midranges/dsm-50-ffl-8-ohm
On page 64 I said: “I have done a couple speakers recently with low-priced mid-domes---”
The most recent is a budget build using the HIVI DMB-A. The tweeters are SB19ST-C000-04. The 8” woofers are from 1976 Acoustic Research AR-16; they play pretty solidly to 40hz, in .64cuft, with about 85dB sensitivity.
Profiguy and others are right that the DMB-A needs a series-notch (called “conjugate”?) to tame the low end resonance peak, and that makes it expensive to implement. I found that rolling it off above 4300hz was even tougher yet. Overall, the 3way network uses 10 reactive components, and 4resistors. I think that for builds with with cone mids and low order filters, I have employed significantly fewer parts than this.
I have had the DMB-A pair for several years. I got them at first because they would drop into my 1972vintage AR3a cabinets. I ended up using some (NLA) Dayton DC50FAdomes there instead, because they could cross lower. The most troublesome part of the DC50FA, was a significant dip/peak, just below 2000hz, as I remember.
Both of these AR rebuild projects found me interested in wave-guides. A seven inch round wave-guide worked out OK on the DC50FA, but a similar one exaggerated the 4500hz on-axis dip on the DMB-A. The AR3a ended up with the round WG integrated into a “wave-guide grill-frame” that fits into its deep baffle recess. The AR-16 rebuild has directivity modifying elements integrated in to its baffle perimeter, a shallow circular wave-guide-extension on theSB19 tweeter, as well as some physical time-alignment efforts. I like the forward/directional character in my small/busy listening space; but with only one prototype, I have yet to experience its (soon, "their") ability, or lack thereof, to make a nice sound-stage/image.
Wave-guides do change the presentation of my mid domes. The more forward presentation, and comparatively more extended top-end (from HIVI Q1R tweeters) of the remodeledAR3a's, is appealing to me (if possibly distasteful to vintage purists).
I hope the project context here is useful to some, rather than purely distracting. I think the vintage gear re-purposing may be a bit obscure to others.
The most recent is a budget build using the HIVI DMB-A. The tweeters are SB19ST-C000-04. The 8” woofers are from 1976 Acoustic Research AR-16; they play pretty solidly to 40hz, in .64cuft, with about 85dB sensitivity.
Profiguy and others are right that the DMB-A needs a series-notch (called “conjugate”?) to tame the low end resonance peak, and that makes it expensive to implement. I found that rolling it off above 4300hz was even tougher yet. Overall, the 3way network uses 10 reactive components, and 4resistors. I think that for builds with with cone mids and low order filters, I have employed significantly fewer parts than this.
I have had the DMB-A pair for several years. I got them at first because they would drop into my 1972vintage AR3a cabinets. I ended up using some (NLA) Dayton DC50FAdomes there instead, because they could cross lower. The most troublesome part of the DC50FA, was a significant dip/peak, just below 2000hz, as I remember.
Both of these AR rebuild projects found me interested in wave-guides. A seven inch round wave-guide worked out OK on the DC50FA, but a similar one exaggerated the 4500hz on-axis dip on the DMB-A. The AR3a ended up with the round WG integrated into a “wave-guide grill-frame” that fits into its deep baffle recess. The AR-16 rebuild has directivity modifying elements integrated in to its baffle perimeter, a shallow circular wave-guide-extension on theSB19 tweeter, as well as some physical time-alignment efforts. I like the forward/directional character in my small/busy listening space; but with only one prototype, I have yet to experience its (soon, "their") ability, or lack thereof, to make a nice sound-stage/image.
Wave-guides do change the presentation of my mid domes. The more forward presentation, and comparatively more extended top-end (from HIVI Q1R tweeters) of the remodeledAR3a's, is appealing to me (if possibly distasteful to vintage purists).
I hope the project context here is useful to some, rather than purely distracting. I think the vintage gear re-purposing may be a bit obscure to others.
@Troy Madden Yes, that one's been briefly mentioned. Its a great metal dome mid. I've used it in several builds. Its been around since the late 1980s in West Germany and its likely one of the best 2" metal domes. Very detailed sounding without being in your face. I recommend removing the FF, but then you have to cross it a little higher around 800 hz. It pairs up nicely with most 25mm Ti and Alu HF domes. The DSM25FFL is the intended counterpart HF dome that goes with it.
Alright, I am on a bit of a mission here. I was at AXPONA 2025 this weekend and this 55mm dome is the greatest mid range I have ever heard, bar none. This speaker is made by PMC. I spoke with the speaker designer and he told me the waveguide is integral. I am not sure we can purchase that but I'm sure we can DIY a decent copy and maybe even improve it. The hunt is on....
I am in contact with Playback Distributions who needs the part number of the dome for me to order them.
The closest thing I have found to a part number is off of the their site which lists the dome as such
https://playbackdistribution.com/products/pmc-prophecy7
Any internet slueths/speaker slueths able to find the part number on these? I want a set so bad.
I am in contact with Playback Distributions who needs the part number of the dome for me to order them.
The closest thing I have found to a part number is off of the their site which lists the dome as such
https://playbackdistribution.com/products/pmc-prophecy7
Any internet slueths/speaker slueths able to find the part number on these? I want a set so bad.
These are going in my next project. I'm going to order early, before they have them in stock, just so I can ensure I get a set.
The part number is probably PMC55.
I doubt they would sell the OEM driver other than as a replacement for a cabinet they have sold.
The Prophecy 7 waveguide for the mid and tweeter looks like it would be an easy print.
OK, I'll throw this back at them and see what they say. The speaker designer said I could most likely buy it as a replacement speaker because they sell all of them as replacements. That, so far, is turning out to be true.
Playback did give me a cost for shipping charges already.
If only I had also brought with a calipers..... Could have had exact dimensions in about 10 seconds.... (joking of course)
@Bmsluite I suspect that dome is a Dynaudio product with a PMC added WG. The dome itself and lead wires are very similar to the D52AF. The chamber is also a giveaway if it looks like the one used on the D52AF. Its also very easy to remove the OEM faceplate and substitute a custom WG.on this mid.
They may not sell these mids to DIY anymore but Dynaudio still make them for other companies. You can also have them repair your old D52AFs, so they also make the dome asy.
They may not sell these mids to DIY anymore but Dynaudio still make them for other companies. You can also have them repair your old D52AFs, so they also make the dome asy.
I don't think they are Dynaudio D52AFs. Those have this back shell
Where the PMC has this back shell
Somebody has these Dynaudios for sale. They look even larger
@mikessi Here's a sneak peak at the source electronics and amplification. As you can see I don't have a shortage in the amp department. I had to clean up the wiring a bit from our last little escape with the electrical supply. The bottom amps are run on a separate 20A supply.
Attachments
No wonder you need aircon with so much amplification!
But seriously, hope your communities, including DIYAudio, keep you feeling positive. All the best!
But seriously, hope your communities, including DIYAudio, keep you feeling positive. All the best!
