Hello people,
I opened this thread for particular kind of loudpeaker, slowly it's becoming dcx discussion 😊
Doesn't matter, I respect vox populi and like dcx, so let's join the boat 😉
@kevinkr ; fully agree that original PS had to go out. Little bit less I understand need for clock upgrade, and totally don't understand what was the problem with AES digital input, that Chrystal chip after transformer accepts almost anything? Can you tell me why was this worth the effort?
Also from pictures and description of your dcx I didn't figure out how is volume control solved? For me that was largest issue with dcx, I solved it for the moment with 6 gang Alps pot made for home cinema, but it's still not 100% to my liking.
Cheers,
Dražen
I opened this thread for particular kind of loudpeaker, slowly it's becoming dcx discussion 😊
Doesn't matter, I respect vox populi and like dcx, so let's join the boat 😉
@kevinkr ; fully agree that original PS had to go out. Little bit less I understand need for clock upgrade, and totally don't understand what was the problem with AES digital input, that Chrystal chip after transformer accepts almost anything? Can you tell me why was this worth the effort?
Also from pictures and description of your dcx I didn't figure out how is volume control solved? For me that was largest issue with dcx, I solved it for the moment with 6 gang Alps pot made for home cinema, but it's still not 100% to my liking.
Cheers,
Dražen
Latest update on Beetlejuice; while I did not do any more mods or measurements, I was listening in 6db/octave on 410 hz, This does sound very good.
Even my wife (she is by the way an movie editor and spends her every working day in front of studio monitors, but otherwise not interested in hi-fi) unprovoked said last night while we were watching the movie " you did something here, this sounds great now"....
She also made one very important acoustic correction; Eyes got cat ear hat for ideally disturbing reflection sound:
Even my wife (she is by the way an movie editor and spends her every working day in front of studio monitors, but otherwise not interested in hi-fi) unprovoked said last night while we were watching the movie " you did something here, this sounds great now"....
She also made one very important acoustic correction; Eyes got cat ear hat for ideally disturbing reflection sound:
Small update, didn't do much but listening, I started to like these alcone subwoffer drivers, in bass reflex they go deeeep and crisp. These are super low Qts of only 0.23 and quite strong motor, BR works very fine with huge 130mm tube tuned under drivers resonance, at some 25hz.
Hi, It took me a while to find free time for audio, and than I went to finish one thing that was occupying my desk. So happy something is brought to an end 
.
It is this PA 6 channel amp that I bought very cheap (2 of them identical) and the idea was to use it with DCX as speaker development tool.
I thought just to rewire it a bit as it was horribly noisy, but I ended up changing everything except PCB's and chassis (and they were very much modified too), I think over 40 mods altogether. On the picture below; to the right is original, and to the left an unit that I finished with. At least now its quiet as a tomb (or almost) and has much more ampere capability:
This will now be my permanent tool in pair with modified DCX (as in post #13) at some stage I'll built linear PSU for DCX, but that will wait.
However I would not recommend anyone to do this in a way I did, after spending probably 250 Euro (12 Sanken output transistors, 800VA custom transformer, caps from stock, speaker posts x 12, 6 gang Alps and you name it all). Just after this I bought 2 multichannel receivers on scrapyard; Sony STR-dg700 for 10 Euro !!!! and Rotel RSX-1055 for 20 Euro!!! They both have potentiometers and Sony has 6 channels, Rotel only 5 channels so one is missing for DCX.
So only thing needed to make DCX very useful and practical is to dig out single ended outputs (like in post # 13) and buy good quality second hand multichanel receiver... Good enough for testing XO's, enclosures and room acoustics.
.It is this PA 6 channel amp that I bought very cheap (2 of them identical) and the idea was to use it with DCX as speaker development tool.
I thought just to rewire it a bit as it was horribly noisy, but I ended up changing everything except PCB's and chassis (and they were very much modified too), I think over 40 mods altogether. On the picture below; to the right is original, and to the left an unit that I finished with. At least now its quiet as a tomb (or almost) and has much more ampere capability:
This will now be my permanent tool in pair with modified DCX (as in post #13) at some stage I'll built linear PSU for DCX, but that will wait.
However I would not recommend anyone to do this in a way I did, after spending probably 250 Euro (12 Sanken output transistors, 800VA custom transformer, caps from stock, speaker posts x 12, 6 gang Alps and you name it all). Just after this I bought 2 multichannel receivers on scrapyard; Sony STR-dg700 for 10 Euro !!!! and Rotel RSX-1055 for 20 Euro!!! They both have potentiometers and Sony has 6 channels, Rotel only 5 channels so one is missing for DCX.
So only thing needed to make DCX very useful and practical is to dig out single ended outputs (like in post # 13) and buy good quality second hand multichanel receiver... Good enough for testing XO's, enclosures and room acoustics.
Than , with new amp setup, back to the speakers.
I ditched power amplifiers out of the Tubes (see pictures in post #5) as they are way too big and very impractical. This liberated some more space to insert little bit more absorption material.
Oh dear how much time I spent then when I was building amps in to the enclosure. It is very labor consuming to fit heat sink, XLR, switch, mains socket in a round shape, and make it air tight.
Building active speaker (particularity in odd shape enclosure) was very overly ambitious (not to say plain stupid) thing from me. All DIY projects (when not bought as complete developed projects) are beta projects, one off items , change of mind or wish to improve (or just change ) will inevitably come.
That was jut a thought, advice is don't built amp into speaker if you are not 100% sure that is it forever, or you are not professional speaker builder and this is prototype No10.
I ditched power amplifiers out of the Tubes (see pictures in post #5) as they are way too big and very impractical. This liberated some more space to insert little bit more absorption material.
Oh dear how much time I spent then when I was building amps in to the enclosure. It is very labor consuming to fit heat sink, XLR, switch, mains socket in a round shape, and make it air tight.
Building active speaker (particularity in odd shape enclosure) was very overly ambitious (not to say plain stupid) thing from me. All DIY projects (when not bought as complete developed projects) are beta projects, one off items , change of mind or wish to improve (or just change ) will inevitably come.
That was jut a thought, advice is don't built amp into speaker if you are not 100% sure that is it forever, or you are not professional speaker builder and this is prototype No10.
Then I went back to measurements, still near field mic 1m distance from speakers. I wanted to try if near wall reflections are making big dips in bass region and if simple absorption material will make any change. Big piece of egg crate foam was inserted behind speaker:
The result is following, RED trace with no foam, green trace with foam, almost no difference:
The result is following, RED trace with no foam, green trace with foam, almost no difference:
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Next step was moving the microphone to listening position, finally some very good news: the response in place where it really matters is much more even.
Below are responses as is (in red) and with applied generic filter from REW (in green) :
I am becoming very very happy now, with not so much EQ the response is almost flat 20 - 20,000 Hz. From the Eye and B80 driver I was expecting good result, but really surprising is that 50 L BR enclosure with 10" driver can do under 20Hz flat in room with very little EQ.
Below are responses as is (in red) and with applied generic filter from REW (in green) :
I am becoming very very happy now, with not so much EQ the response is almost flat 20 - 20,000 Hz. From the Eye and B80 driver I was expecting good result, but really surprising is that 50 L BR enclosure with 10" driver can do under 20Hz flat in room with very little EQ.
Next step was to make EQ in DCX directly for new tests and I bought usb to serial cable to make it easier play with settings through pc.
But shock and awe, even it says on the box it's windows compatible, yes it is except for windows 11, grrrrxxx. 18 euro in a bin!
Does anyone know how to trick windows11 to use driver for windows 10?
But shock and awe, even it says on the box it's windows compatible, yes it is except for windows 11, grrrrxxx. 18 euro in a bin!
Does anyone know how to trick windows11 to use driver for windows 10?
About designing bass , the Tube. At beginning I was not very happy with this Alcone driver. Qts of only 0.23 (0.23 is datasheet, 0.25 is calculated) was an question. Keep in mind that this is my almost first more serious speaker design attempt. These are driver parameters:
Then I was visiting original supplier and looking what do they have to say about it, they recommended tuning BR enclosure much lower than Fs:
https://www.lautsprechershop.de/hifi/aka_tief_en.htm
I did, and the simulation result is this:
There was also discussion there about adding resistor in series with speaker, that would raise Q a lot, here is simulation with 2 ohm, looks perfect:
I tested series resistance , see post #6, but the result was nothing like the simulation, so the idea is dropped.
At the end I left BR tuning at some 25 Hz, which is at least 7 Hz less than driver in the box Fs, and result in room is (at least for me) quite good. I think there is not much music under 40Hz, so this bottom end is mainly for movie effects.
Did anyone try this way, what are yours experiences?
Then I was visiting original supplier and looking what do they have to say about it, they recommended tuning BR enclosure much lower than Fs:
https://www.lautsprechershop.de/hifi/aka_tief_en.htm
I did, and the simulation result is this:
There was also discussion there about adding resistor in series with speaker, that would raise Q a lot, here is simulation with 2 ohm, looks perfect:
I tested series resistance , see post #6, but the result was nothing like the simulation, so the idea is dropped.
At the end I left BR tuning at some 25 Hz, which is at least 7 Hz less than driver in the box Fs, and result in room is (at least for me) quite good. I think there is not much music under 40Hz, so this bottom end is mainly for movie effects.
Did anyone try this way, what are yours experiences?
Everything is flat when you use 400dB scale (-200dB to +200dB). Normally it should be 50dB scale.
I seriously doubt you hear anything below threshold of hearing (10dB), so negative scale does not make much sense. Plus our living rooms have about 30-40dB background noise anyway. Unless you live in anechoic chamber (totaly unpleasant).
Orherwise nice speakers.
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Hi Adason,
Thanks for comments!
I agree with the scale, I attempted to put full range in one picture, otherwise it'll be ribbon. When I get home I'll resize the plot and publish.
From noise and subjective point, oh man, I have tinnitus and my left ear loses anything above 8khz, right ear goes off above 12khz. No expensive tweeters for me 🥴, i did audio examination in hospital few months ago... Nevertheless I use my wife who is movie editor and knows the sound, and 8 year old son as reference for what sounds good, when my destroyed hearing is irrelevant.
Thanks for comments!
I agree with the scale, I attempted to put full range in one picture, otherwise it'll be ribbon. When I get home I'll resize the plot and publish.
From noise and subjective point, oh man, I have tinnitus and my left ear loses anything above 8khz, right ear goes off above 12khz. No expensive tweeters for me 🥴, i did audio examination in hospital few months ago... Nevertheless I use my wife who is movie editor and knows the sound, and 8 year old son as reference for what sounds good, when my destroyed hearing is irrelevant.
Hi, here is Hi Res picture from post #27, mid room measurements; RED no EQ, BLUE with generic EQ (just attenuation, no gain allowed)
I might be wrong, gentle peak around 2 khz seems to be Visaton B80 characteristic, I seen this in factory data sheet and independent measurements. Peeks in bass region appear every octave, 30, 60, 120 Hz... I guess this is room response???? Do I read this right?
I might be wrong, gentle peak around 2 khz seems to be Visaton B80 characteristic, I seen this in factory data sheet and independent measurements. Peeks in bass region appear every octave, 30, 60, 120 Hz... I guess this is room response???? Do I read this right?
Apropos, hereby I publish something I did not see anyone else published before, my personal frequency sweep graph, these below are my ears and what they measured at hospital, I went there for tinnitus, they concluded that my ears are completely healthy and tinnitus is coming from somewhere else, only suspect is my brain.
Just consider, this is characteristic of instrument I have for listening, considered to be healthy (for me as 56 y.o.), this is not exactly calibrated Mic ,how do your ears measure?
Just consider, this is characteristic of instrument I have for listening, considered to be healthy (for me as 56 y.o.), this is not exactly calibrated Mic
,how do your ears measure?