Hello Steve
Here is a FR with only 2 curves (from the measurements of the post 5270). The measurement distance was 1m.
- blue : with the 6.8µF capacitor
- green : with out
Christian
Hello Eucy
About epoxy, it is my understanding too;
You can have a look on post #5130. It is a test I did adding a about 8g washer at the exciter. There is an effect of the mass but not important I would have thought. 8g is a lot compare to the voice coil. There have been posts showing exciter assembly with nuts or some additional part (Dayton Audio,).
For the contact area, it is my opinion too. I made some test to try to reduce the contact area but with no success.
Christian
I did manage to complete the system in time for the party that want off last weekend. Really got everything together in the last minute, and had done a bit of testing indoors with the amps, but never had the time to do any proper testing with the whole system and basses. But made an agreement with the guy I rented the basses from that he would bring tops as a backup should not my plates be able to keep up with the basses.
To my great relief panels could keep up with the 4x double 18" L'Acoustics SB218 basses. I had to push the amps just below limiting with 8 ohm load, but got amazingly clear and distortion free sound.
The result and reactions was well beyond what I could have hoped for. The whole dancefloor was like a giant sweetspot, the sound was really loud but clear and non-fatiguing. I lost count of the number of people telling me it was the best sound system they ever heard, many of them fanatic festival visitors having been to most of the major psytrance festivals in Europe and elsewhere. I just cannot understand why DML panels doesn't already dominate the PA market since the result is so superior, but I'm very confident that they will in the future.
I will make a post soon with more details about the system and upload some pictures.
To my great relief panels could keep up with the 4x double 18" L'Acoustics SB218 basses. I had to push the amps just below limiting with 8 ohm load, but got amazingly clear and distortion free sound.
The result and reactions was well beyond what I could have hoped for. The whole dancefloor was like a giant sweetspot, the sound was really loud but clear and non-fatiguing. I lost count of the number of people telling me it was the best sound system they ever heard, many of them fanatic festival visitors having been to most of the major psytrance festivals in Europe and elsewhere. I just cannot understand why DML panels doesn't already dominate the PA market since the result is so superior, but I'm very confident that they will in the future.
I will make a post soon with more details about the system and upload some pictures.
Hi Christian
What I see from your test is a drop in mid/high freq range for the added mass case..increasing from zero @ 100hz to almost 20dB @8k
Surely that's a very(!) big effect, and would worsen with increased mass.
I wouldn't expect the range to be reduced by much but the excursion at each freq would be compromised, less so at low freq, more at high freq.
Eucy
Can’t wait to hear more details! Glad it worked out so well. Very satisfying I’m sure!
In your original post 5270 i do not see a plot closely matching the blue line up to 4k ?
Then rolling off ?
Maybe it is my eyes 😲
what is your conclusions ,cause, of the roll off with two exciters without capacitor ?
Steve.
You were very brave to have thrown all of the the system together in time, I would have been in panic mode😱
I'm glad it all worked out well with great sounds.
it's great everyone getting the full performance ,no matter where they are .
looking forward to some photo's.
Steve.
Thanks, and yes Steve, I was a bit nervous for sure 🙂
I'm nervous every year, and it really seemed like insanity to take on the extra stress. I felt confident from my experiments that I was on to something, but from there to be able to outperform pro gear consistently over a whole festival over several days...well, it probably was insane to try and I was just very lucky that it held up 🙂
For the plates I decided to stick with Neopor coated with hide glue and shellac. I'm very happy with the performance, and cost per panel is very low. On each 500x330x25mm panel I put 4x DAEX30HESF-4. I put the exciters closely together with both x and y positions slightly skewed and glued them on using epoxy.
With the skewed configuration, making a spine was a bit more tricky, and I tried some different solutions, but regardless of what I did I could not get as good sound as with unsupported exciters, and had some distortion showing up in measurements. I tried with different amount of pressure on the exciters, using different adhesive and damping on the spine, but without luck. Since time was getting tight I decided to go with spineless frames instead.
However, when doing a stress test playing a lot of bass on an extremely hot veranda I noticed some distortion. Playing a 60hz tone and slightly touching some exciters it was obvious that distortion disappeared if just holding up some affected exciters very slightly. Temperature was really extreme, and when using a HPF I cannot get the DAEX30HESF-4 to heat up at all over ambient temperature it seems, so while it seemed unlikely to be an issue in actual usage, I simply added some strings taped on to the frame as a desperate last minute fix. Combined with the chaotic cable management, they look a bit of a mess right now, but will try to figure out a distortion free way of suspending the exciters and tidy up the cabling.
I adjusted the plate suspension to be very minimal, with only a few 2cm foam strips holding the plate in place. This helped smoothing out the FR and improve bass response a lot compared to my earlier tests with more suspension. While they will not be able to push enough air to replace proper subs, if I push up the bass a bit with EQ they do make for a surprisingly decent full range system as well.
Using epoxy to fix the exciters seems to have resulted in better HF response than I was getting with tape, and while it still sloped off quite a bit above 7k I actually ended up reducing the HF in the end. With the wide dispersion and reach of the HF, it seems like a bit of extra roll off is needed to not result in an overly bright perception compared to regular speakers. So the natural roll off I was getting actually seems quite neutral, and I had to tone HF down very slightly to get a slightly warmer than neutral tone, which is my preference.
The Sanway D2S amps really impressed me. Everything seems done right. Easy to tweak levels, eq and limiters in realtime, excellent power protection, silent and temperature controlled fans, quality connectors, etc. Haven't done any output measurements, but subjective impression is that it lives up to the rated 2x500w in 8 ohm, and does so with very clean sound.
However, I still think I have not pushed the plates to the maximum. Exciters are not getting even lukewarm after 12 hrs of use, and not a hint of distortion from the plates. I will test running bridged for 1800w in 4 ohm when I get a chance and see what happens. It would be almost 3x the rating of the exciters, but hopefully I will get a bit better sense of what their actual limit is in practical usage. It is very possible that half the plates would be sufficient to deliver the same experience, or that this setup could go insanely loud over very big area with more amplification.
Mobile recordings of PA systems usually do not say a lot, since everything becomes a distorted mess. But here is a video shot some 30-40m away from the dancefloor, which I guess give some indication about the loudness. (Apparently it was audible on a camping site 3.6km away over forest and quite uneven terrain. That is the first time in the 10 editions we done so far.)
https://drive.google.com/file/d/1fxUo9T3XxfEODbqAU8kiqNXHstAyVmD4/view?usp=sharing
Here is a video showing a speaker stack closely during sound check:
https://drive.google.com/file/d/1kdh1yNhkZY9F1waNljSoVIBvRwwy2Uj0/view?usp=sharing
Here is a video of the dancefloor during the night:
https://drive.google.com/file/d/17_3u1bt28VpCXvznFyX0TkftK3jj4rHK/view?usp=sharing
Will dig out some of the measurements of the plates later, they are on another laptop not yet unpacked.
I'm nervous every year, and it really seemed like insanity to take on the extra stress. I felt confident from my experiments that I was on to something, but from there to be able to outperform pro gear consistently over a whole festival over several days...well, it probably was insane to try and I was just very lucky that it held up 🙂
For the plates I decided to stick with Neopor coated with hide glue and shellac. I'm very happy with the performance, and cost per panel is very low. On each 500x330x25mm panel I put 4x DAEX30HESF-4. I put the exciters closely together with both x and y positions slightly skewed and glued them on using epoxy.
With the skewed configuration, making a spine was a bit more tricky, and I tried some different solutions, but regardless of what I did I could not get as good sound as with unsupported exciters, and had some distortion showing up in measurements. I tried with different amount of pressure on the exciters, using different adhesive and damping on the spine, but without luck. Since time was getting tight I decided to go with spineless frames instead.
However, when doing a stress test playing a lot of bass on an extremely hot veranda I noticed some distortion. Playing a 60hz tone and slightly touching some exciters it was obvious that distortion disappeared if just holding up some affected exciters very slightly. Temperature was really extreme, and when using a HPF I cannot get the DAEX30HESF-4 to heat up at all over ambient temperature it seems, so while it seemed unlikely to be an issue in actual usage, I simply added some strings taped on to the frame as a desperate last minute fix. Combined with the chaotic cable management, they look a bit of a mess right now, but will try to figure out a distortion free way of suspending the exciters and tidy up the cabling.
I adjusted the plate suspension to be very minimal, with only a few 2cm foam strips holding the plate in place. This helped smoothing out the FR and improve bass response a lot compared to my earlier tests with more suspension. While they will not be able to push enough air to replace proper subs, if I push up the bass a bit with EQ they do make for a surprisingly decent full range system as well.
Using epoxy to fix the exciters seems to have resulted in better HF response than I was getting with tape, and while it still sloped off quite a bit above 7k I actually ended up reducing the HF in the end. With the wide dispersion and reach of the HF, it seems like a bit of extra roll off is needed to not result in an overly bright perception compared to regular speakers. So the natural roll off I was getting actually seems quite neutral, and I had to tone HF down very slightly to get a slightly warmer than neutral tone, which is my preference.
The Sanway D2S amps really impressed me. Everything seems done right. Easy to tweak levels, eq and limiters in realtime, excellent power protection, silent and temperature controlled fans, quality connectors, etc. Haven't done any output measurements, but subjective impression is that it lives up to the rated 2x500w in 8 ohm, and does so with very clean sound.
However, I still think I have not pushed the plates to the maximum. Exciters are not getting even lukewarm after 12 hrs of use, and not a hint of distortion from the plates. I will test running bridged for 1800w in 4 ohm when I get a chance and see what happens. It would be almost 3x the rating of the exciters, but hopefully I will get a bit better sense of what their actual limit is in practical usage. It is very possible that half the plates would be sufficient to deliver the same experience, or that this setup could go insanely loud over very big area with more amplification.
Mobile recordings of PA systems usually do not say a lot, since everything becomes a distorted mess. But here is a video shot some 30-40m away from the dancefloor, which I guess give some indication about the loudness. (Apparently it was audible on a camping site 3.6km away over forest and quite uneven terrain. That is the first time in the 10 editions we done so far.)
https://drive.google.com/file/d/1fxUo9T3XxfEODbqAU8kiqNXHstAyVmD4/view?usp=sharing
Here is a video showing a speaker stack closely during sound check:
https://drive.google.com/file/d/1kdh1yNhkZY9F1waNljSoVIBvRwwy2Uj0/view?usp=sharing
Here is a video of the dancefloor during the night:
https://drive.google.com/file/d/17_3u1bt28VpCXvznFyX0TkftK3jj4rHK/view?usp=sharing
Will dig out some of the measurements of the plates later, they are on another laptop not yet unpacked.
They only got filled to the top of the black and then sanded down smooth and small as possible. The tape is just there so as not to make a mess. These tv speakers are tiny but overbuilt, I'm sure the big name brands don't want a bunch of RMA's due to speaker failures. They sound plenty good enough to use as a shop or patio speaker once you get them dialed in.
Leon.
The recordings sound pretty good to me.
The lead out wires and terminals will put the exciters well out of balance, and start to wobble the exciter and scrape the voice coils.
Especially if going down to 60hz .
What XO did you use for the DISCO🤣
Steve.
The recordings sound pretty good to me.
The lead out wires and terminals will put the exciters well out of balance, and start to wobble the exciter and scrape the voice coils.
Especially if going down to 60hz .
What XO did you use for the DISCO🤣
Steve.
Great Leob!
It is a pleasure to read more details (sorry I just see you have posted...)
The reactions you had highlight the quality of DML : almost no directivity, low influence of the surrounding, no crossover...
The lack of popularity is perhaps in the second side of the coin: how to label a DML when the standard of measurement is a FR in the axis in an anechoic chamber. In a world where the reference is a power response in a real room, it might be perhaps different.
In addition to that, to get the full potential, it needs to master the panel and the chain in front with some EQ which are technology from different fields and ages.
Some months ago, I made the suggestion to test DML on a forum where the question was to give a speaker to an electronic piano. No way for a DML try, the opinion that a modal speaker can work was too strong.
The kind of feedback you have had are the most rewarding.
Christian
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Hello Steve
Might be I didn't select the same set of curves but you can see the 4k roll off in the second graph of the post 5270.
I think the principle remains and is ok at least for a try by somebody interesting in a dual exciter configuration.
Without making measurements at short distance, I have no conclusion about the cause of the roll off with 2 exciters without capacitor. Depending of the measurement and its post treatment, the curve changes. With the capacitor, it is less sensible.
I am in the opinion, the capacitor is a good option
Christian
Thank you Leob
Really impressive.
Would you mind to post some technical details : position of the exciters, position of the foam (seems very little on each vertical sides) and may some pictures here in case the video are not accessible for long.
Just added the link to your post in the "history file"
Christian
Hi Eucy,
I have pushed a bit more the use of the records by displaying the difference and comparing it to a 1st order filter
It doesn't fit too badly from LF to 1k. After the slope is no more -6dB/oct (-3dB/oct?). It reminds me a cascade of 1st orders to filter a white noise in pink noise... but no idea of the physics behind.
Christian
Great stuff Leon 👍👍👍
Very pleased they were a hit with the crowd
Maybe some form of spider for supporting the group..
Cheers
Eucy
Thanks Christian
I think it's pretty clear that a light coil assembly is needed for good hf. I'll stick with that approach anyway.
Also a small contact area on the exciter, (and maybe also a tapered thinning of the panel at the exciter.. haven't tried that but it has been mentioned elsewhere)...
I'm getting close to 20k anyway, so I'm satisfied with the hf end
Cheers
Eucy
I have mentioned before about trying to blend subs in with dml panels, the panels seem to have so much more going on on them, that I have to have the subs turned up that much higher to match them !
So I usually end up with a sloping response to the hf , similar to a room response plot .
When I EQ to a flat response it sounds week in the low end .
one time I tried to level match my DMLs to my TLS mid and treble, by the time I had matched them by ear, I found that I had almost turned the DMLs off ? If that makes sense ?
some dml panels already have a sloping response, so I don't worry too much as that will(may) blend in well with the subs ?
this is why I would recommend strong powerful subs, even with my small , below 30cm 10watt panels .
Steve.
I think I am going to make a recording today of my card panels, but this time I am going to have them full range near field, about 30cm between the phone microphones and panels, with the panels pointing directly at each other .
To give an idea of the sound ,if used as a desk top speaker.
might be interesting ?
Steve.
To give an idea of the sound ,if used as a desk top speaker.
might be interesting ?
Steve.
Hi Eucy
I agree : low mass, low inductance are elements of my specifications.
Small contact area makes sense also. Something to push?
Thinning the panel at exciter it is something I think tested by Spedge. The way I did it is with XPS panel to limit the HF.
An other characteristic near the exciter might an higher local stiffness.
Christian