OK, That's good to know. To be sure I get it, I assume the extra panels are in parallel with the rightmost panel shown in the attached, which are the 8th panels in a '63 if I am correct.
I am going to pick up a derelict pair of Gradient subs which I will rebuild. Curious how that improves the '63 and/or betters the '989.
BTW I find the '989s gorgeous in a majestic way. I have 'm covered with a soft white sock. 😎
Jan
I am going to pick up a derelict pair of Gradient subs which I will rebuild. Curious how that improves the '63 and/or betters the '989.
BTW I find the '989s gorgeous in a majestic way. I have 'm covered with a soft white sock. 😎
Jan
Attachments
Picture of socked quad please? 🙂
Isn't the gradient just an OB sub? And if so, would it be better to DIY your own with the latest modern drivers + relevant EQ?
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Isn't the gradient just an OB sub? And if so, would it be better to DIY your own with the latest modern drivers + relevant EQ?
//
Yes it is an open baffle doublet, as advocated by Siegfried Linkwitz.
I will have to replace the drivers but the box fits the '63 base exactly. Additional benefit is raising the '63 a bit.
Jan
I will have to replace the drivers but the box fits the '63 base exactly. Additional benefit is raising the '63 a bit.
Jan
How about making a lot of small esl speakers (headphones) to make an array? And driving them direct? Would that make things easier for the amp design? It would be easy to make hf, middle, bass sections and curve the whole speaker...
I've been playing around with 3d printed frame + wire headphones.
I've been playing around with 3d printed frame + wire headphones.
There you got a point. I am going to take the top and bottom basket to a paint shop to give it a nice glossy coat.
I'm thinking of BMW Arctic Grey 😎
Matching a dynamic driver to an electrostatic driver is not easy. Peak deflection of an electrostatic driver happens with peak voltage, However max displacement of a dynamic is at peak current which is not usually peak voltage. Its a more serious issue for microphones. To match a Quad 63 with an Entec subwoofer I recommend 100 Hz and set the woofer (sealed box) about 3 feet (1M) closer than the quad. If you look at the spectral distribution of energy in music its usually split around 150 Hz. Using that as a crossover point will bring some significant additional peak dynamic. Remember the deflection for a specific SPL decreases with frequency. A higher crossover will allow much higher peak output before breakdown. Adding more bass drivers to a Quad could backfire. They do have a resonance and its pretty strong.
At 100 Hz and below the wavelengths are so long (10'+) the structures need to be enormous to get directivity. Its possible https://www.nbcnews.com/video/see-t...enter-of-south-koreas-propaganda-597470275932 but not too practical.
At 100 Hz and below the wavelengths are so long (10'+) the structures need to be enormous to get directivity. Its possible https://www.nbcnews.com/video/see-t...enter-of-south-koreas-propaganda-597470275932 but not too practical.
Demian are you familiar with the Gradient subs for the ESL 63? They are open baffle, two drivers per enclosure, one backwards to cancel some excursion related distortion.
Presumably these are easier to match, them being dipoles like the panels. The units were endorsed by Peter Walker at the time.
https://manualmachine.com/gradient/sw63/2335821-owners-manual/
Jan
Presumably these are easier to match, them being dipoles like the panels. The units were endorsed by Peter Walker at the time.
https://manualmachine.com/gradient/sw63/2335821-owners-manual/
Jan
I am aware of them. I don't have first hand experience of them however. One thing to keep in mind- if you couple a dipole woofer closely to a quad you will be displacing the quad diaphragms with the woofer excursion. You could increase the potential for arcing and the quad is actually pretty transparent acoustically so you don't get bass extension of the woofer with the panel.
At the first glance you are right but if you consider the open air around the speakers the effect is quite low, the air impedance is low. However if you stuck the speakers close to the side walls the coupling will be higher and the output will be higer since the baffle will be infinite on one side. This will increase the low frequency responce and as you mention also load the 63´s slightly more, but then you have to compensate with an eq and attenuate the low frequency to get a straight responce.
Made some progress today. Finalized the little HV switch PCB, tested it and mounted it in one of the ESL 989's.
This will allow switching the stator drive between the step-up transformer output, driven by a conventional amp, and the output of my direct-drive amp.
The cabling between the DD-amp and the speaker has a control line to the little controller on this PCB, so the amp can control which output is playing (and a few other things), and that in turn is IR-remore controlled.
That should give an interesting comparison opportunity.
The main HV amplifier boards are nearing completion as well.
Jan
This will allow switching the stator drive between the step-up transformer output, driven by a conventional amp, and the output of my direct-drive amp.
The cabling between the DD-amp and the speaker has a control line to the little controller on this PCB, so the amp can control which output is playing (and a few other things), and that in turn is IR-remore controlled.
That should give an interesting comparison opportunity.
The main HV amplifier boards are nearing completion as well.
Jan
Attachments
Jan,
A bit late to the party, but did you manage to refurbish the Gradients, and if so, are you happy with their contribution ?
I once bought those Gradients with high expectations but was not at all convinced that it was a step forward because you heard two different sound characters. So, sold them after a few months and never regretted the decision.
Hans
A bit late to the party, but did you manage to refurbish the Gradients, and if so, are you happy with their contribution ?
I once bought those Gradients with high expectations but was not at all convinced that it was a step forward because you heard two different sound characters. So, sold them after a few months and never regretted the decision.
Hans
Hi Hans,
No, I just took them apart and had the surround of the drivers refurbished.
Too busy finishing the direct dive amps for an audio 😎
But I do intend to reassemble them and try them out, will be in 2023 ...
Jan
No, I just took them apart and had the surround of the drivers refurbished.
Too busy finishing the direct dive amps for an audio 😎
But I do intend to reassemble them and try them out, will be in 2023 ...
Jan
Nice. Those HV reeds. BTW How do they do with small currents - tungsten contacts if memory serves right.
I don't know, I've been using them only a week or so with no issues. Hopefully it stays that way.
Jan
Jan
In regard to DD. Did +/-2 kV, 20 mA max amplifier lately (e-scope beam deflection) using 4.5kV IXYS fets. SRPP kinda of.
Alex, can you share a schematic?
I've tried something like that but had issues to get it to work linearly at higher frequencies due to the MOSFET internal capacitances.
Jan
I've tried something like that but had issues to get it to work linearly at higher frequencies due to the MOSFET internal capacitances.
Jan
Back maybe 15 years ago I was in my "full Quad63" mode - nothing better to do than rebuild panels and experiment.
Decided to build up my own '63 subwoofer so acquired all the necessary parts for a 63 panel but had a friend build up a base that would enclose the the electronics - placed the panel assembly about as high up as the Arcici stands did for the side panels. Drove 4 full-range panels in parallel. Built up a L/R channel combiner which fed a plate amplifier and included a 3-pole LP filter set for around 100hz. Panels blended well and enjoyed the system for many years, till humidity took the rebuilt panels down and I gave up on them. Placed the center channel maybe 18" back from the sides and added a top reinforcing support. Also had the 989's for a while but they overloaded the room too easily.
Charles
Decided to build up my own '63 subwoofer so acquired all the necessary parts for a 63 panel but had a friend build up a base that would enclose the the electronics - placed the panel assembly about as high up as the Arcici stands did for the side panels. Drove 4 full-range panels in parallel. Built up a L/R channel combiner which fed a plate amplifier and included a 3-pole LP filter set for around 100hz. Panels blended well and enjoyed the system for many years, till humidity took the rebuilt panels down and I gave up on them. Placed the center channel maybe 18" back from the sides and added a top reinforcing support. Also had the 989's for a while but they overloaded the room too easily.
Charles
