Thank you Mattes, I'm really grateful for your interpretation and suggestions. I see what you mean regarding the rising impedance and diminished response above 10k - I didn't realize that the rise I see in the graph correlates to the diminished response in the last octave. I’ll definitely take your advice on the shorting ring.
Hentai has been using a nice thick copper ring just below the air gap - I should have enough room for that solution and, should it perform well, it saves me from the need to do any further milling.
In any case, I'm having more aluminum and brass water jet cut next week. When I make the order, I'll ask them to jet out several sets of suitable copper rings for me as well... it should be inexpensive. Again, thank you very much for the suggestion Mattes.
I've assumed that I can tame the small rise in the 7-8k range with a baffle step correction circuit. If that's a poor idea though, please feel free to let me know and I'll explore some other options.
Using bench power supplies at 12V, they seemed to eventually settle down after an hour on 1.9 Amperes or so. I'm also using two supplies, one for each motor. I love your battery idea however.... that's some very clever stuff.
Yes, these lengthily posts have long needed their own thread. In fact, I think I'd really enjoy taking this content (along with some additional details) and telling the story in a series of posts of their own. For example, it seems worth sharing that it was a cancer diagnosis that inspired and led me down this path, four years ago. Life is so beautiful and short... it's important to chase dreams and make the best use of the time we have. I'm very healthy today as I write this, I should add.
However, details like that one may offer more insight and inspiration to others who read this thread, about just how far passion and willpower can take them... and, into how grateful I've been for this conversation as a resource in trying to make a dream of my own come true in the context of potentially having not much time left.
In any case, look for a link to that new diyaudio thread in the near future.
Cheers all,
Ken
Hentai has been using a nice thick copper ring just below the air gap - I should have enough room for that solution and, should it perform well, it saves me from the need to do any further milling.
In any case, I'm having more aluminum and brass water jet cut next week. When I make the order, I'll ask them to jet out several sets of suitable copper rings for me as well... it should be inexpensive. Again, thank you very much for the suggestion Mattes.
I've assumed that I can tame the small rise in the 7-8k range with a baffle step correction circuit. If that's a poor idea though, please feel free to let me know and I'll explore some other options.
Using bench power supplies at 12V, they seemed to eventually settle down after an hour on 1.9 Amperes or so. I'm also using two supplies, one for each motor. I love your battery idea however.... that's some very clever stuff.
Yes, these lengthily posts have long needed their own thread. In fact, I think I'd really enjoy taking this content (along with some additional details) and telling the story in a series of posts of their own. For example, it seems worth sharing that it was a cancer diagnosis that inspired and led me down this path, four years ago. Life is so beautiful and short... it's important to chase dreams and make the best use of the time we have. I'm very healthy today as I write this, I should add.
However, details like that one may offer more insight and inspiration to others who read this thread, about just how far passion and willpower can take them... and, into how grateful I've been for this conversation as a resource in trying to make a dream of my own come true in the context of potentially having not much time left. In any case, look for a link to that new diyaudio thread in the near future.
Cheers all,
Ken
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Hi Ken,
I will for sure be following closely... this is a very exciting thing, and I´m happy if I could help a little. Although I´m very pleased with my own system, I´m fascinated by your project, and I see a chance to may have many questions answered in the future, if you´re willing to share your further efforts, like what will be the effects of the copper ring really? Changes to membrane and whizzer geometry, what effects? Phase plug or not, and if, which form is best?
I think it will be easy to take care about the small rise together with a BSC or, more generally, a correction filter, which in my opinion is needed for a fullrange driver and of course depends a lot on your final enclosure. Others will strongly disagree here...
Once you have a R in series with your driver (as in a BSC), you´re free to manipulate the response with notches parallel to the driver.
So, you´re using 2 PSUs as well... should be all fine then. Battery power is fine as well, but it´s no night and day difference... I use these batteries, just in case: ENERpower 3S7P Battery-Tank 11.1V 20.3Ah Li-Ion DIY Open-End Y-Form – ENERprof
I´m glad you´re making your dreams of your own come true! I think it will be a good idea to take all your contents over in a new thread (but have no idea if this is possible).
All the best
Mattes
I will for sure be following closely... this is a very exciting thing, and I´m happy if I could help a little. Although I´m very pleased with my own system, I´m fascinated by your project, and I see a chance to may have many questions answered in the future, if you´re willing to share your further efforts, like what will be the effects of the copper ring really? Changes to membrane and whizzer geometry, what effects? Phase plug or not, and if, which form is best?
I think it will be easy to take care about the small rise together with a BSC or, more generally, a correction filter, which in my opinion is needed for a fullrange driver and of course depends a lot on your final enclosure. Others will strongly disagree here...
Once you have a R in series with your driver (as in a BSC), you´re free to manipulate the response with notches parallel to the driver.
So, you´re using 2 PSUs as well... should be all fine then. Battery power is fine as well, but it´s no night and day difference... I use these batteries, just in case: ENERpower 3S7P Battery-Tank 11.1V 20.3Ah Li-Ion DIY Open-End Y-Form – ENERprof
I´m glad you´re making your dreams of your own come true! I think it will be a good idea to take all your contents over in a new thread (but have no idea if this is possible).
All the best
Mattes
Ni, Henti, Field coil, gomper
Being a field coil speaker lover for years, I followed this thread with interest but limited skills compared to you guys. I own Fertin 20's, Supravox 2000 EXC's, Classic Audio field coils. My question is the best power supplies to use in the 12v to 15v 3 amp range. I am currently using 4 Lambda variable power supplies Models LP531 FM (2) and (2) LQ531's. I am getting very good sound but with some audible noise. I am looking for the quietest power supplies but not batteries, if possible. Any suggestions would much appreciated.
A YouTube video of my speakers:
Meet Joe, and his amazing DIY horn speakers - YouTube
Thanks in advance,
Joe
Being a field coil speaker lover for years, I followed this thread with interest but limited skills compared to you guys. I own Fertin 20's, Supravox 2000 EXC's, Classic Audio field coils. My question is the best power supplies to use in the 12v to 15v 3 amp range. I am currently using 4 Lambda variable power supplies Models LP531 FM (2) and (2) LQ531's. I am getting very good sound but with some audible noise. I am looking for the quietest power supplies but not batteries, if possible. Any suggestions would much appreciated.
A YouTube video of my speakers:
Meet Joe, and his amazing DIY horn speakers - YouTube
Thanks in advance,
Joe
Hi Joe,
I have tried many PSUs for my FERTIN ACOUSTICS fieldcoils and ended up using large LiIon batteries. Built myself a little device that allows control by a single switch, which (with some relays) switches between pure batterie power (nothing else, is fine for around 10 hours) and loading the batteries (including heating of the fieldcoils with Meanwell medical PSU - I prefer my fieldcoils well warmed up). This allows to listen to music with the Meanwell switching PSU as well, and that is quite good and totally silent. I had quite a few linear PSUs as well. In the end, I went for the batteries, but all in all the differences between a good linear PSU, a switching medical grade PSU and the large batteries (something like this: ENERpower Battery-Tank 11.1V 24.15Ah Li-Ion DIY Open-End Hexagon | ENERprof) are not night and day. I would like to try a current-regulated PSU, but never found anything feasable... and prefer to listen to music instead of hunting PSUs...
All the best
Mattes
When I find time to assemble my field coil speaker setup, I'll be using rod coleman filament regulator which are constant current. If they work for valves then they should be fine for a field coil, at least thats my thinking. The transformer will be a multitapped EI, (not split bobbin but ideally it should be), followed by a LCLC using Lundal's filament chokes. Basically I'll build it along the same lines as the DHT guys build their filament supplies.
I haven't kept up with this thread but was wondering / concerned about the amount of heat generated by the field coil and how to disipate it. Not an issue in open baffles but surely if I was to build an enclosure with the usual stuffing which doubles as an insulator then wouldn't the ambient temperature build up and start to cook the driver. Perhaps a ported enclosure with the ports located above the driver might help allow some of the heat to escape. As I recall my drivers suggest 7-15vdc, so might play it safe although I do wonder if they (D5nf) will sound better at the higher voltage. Not much published info on these drivers.
I am wondering what peoples experiences are with heat (watts, enclosure volume, air flow, enclosure type & stuffing materials),and whether it was much of an issue ?
I haven't kept up with this thread but was wondering / concerned about the amount of heat generated by the field coil and how to disipate it. Not an issue in open baffles but surely if I was to build an enclosure with the usual stuffing which doubles as an insulator then wouldn't the ambient temperature build up and start to cook the driver. Perhaps a ported enclosure with the ports located above the driver might help allow some of the heat to escape. As I recall my drivers suggest 7-15vdc, so might play it safe although I do wonder if they (D5nf) will sound better at the higher voltage. Not much published info on these drivers.
I am wondering what peoples experiences are with heat (watts, enclosure volume, air flow, enclosure type & stuffing materials),and whether it was much of an issue ?
Hi, summerwind
Thank you for your kind comments !!! It only took 40 yrs. !!!
Hi, Mattes
Thanks for your input. I am considering all options but for me it would require 4 separate battery banks and much more room. I may eventually go the battery route but would like to try constant voltage / current power supplies first. I still have a great sounding system so there is time to experiment.
Hi, gupsta
I know some guys who use Rod Coleman regulators and have nothing but good things to say about them. Sounds like that could be a possibility. Thanks for your reply.
Thank you for your kind comments !!! It only took 40 yrs. !!!
Hi, Mattes
Thanks for your input. I am considering all options but for me it would require 4 separate battery banks and much more room. I may eventually go the battery route but would like to try constant voltage / current power supplies first. I still have a great sounding system so there is time to experiment.
Hi, gupsta
I know some guys who use Rod Coleman regulators and have nothing but good things to say about them. Sounds like that could be a possibility. Thanks for your reply.
I can't help you on which to purchase, but I'd definitely be designing my own for this purpose.
Hi Hottattoo,
The Meanwell RPS-60-12 I use for warming up the fieldcoils before listening to music is cheap and dead-silent. Soundwise the difference to batteries is very small, and sometimes I even forgot to switch over to the batteries and just listened to music... would be a compact and cheap start for a larger system. Of course, that´s just a suggestion...
All the best
Mattes
Hi Joe,
You´re welcome!
In fact I was very surprised of the quality of these cheap (don´t remember exactly, but they were maybe around 30€ each) PSUs. First I intended to use them as pre-heating only, just to find out that I can pefectly use them for listening as well... the batteries gave just the last 2%.
In my opinion, there are a lot of very important things to get right in any loudspeaker design, fieldcoil or not, before tuning stuff like PSUs, element quality, cabling and so on becomes your playground... (of course this is not intended to suggest that you haven´t the important stuff right already...)
All the best
Mattes
You´re welcome!
In fact I was very surprised of the quality of these cheap (don´t remember exactly, but they were maybe around 30€ each) PSUs. First I intended to use them as pre-heating only, just to find out that I can pefectly use them for listening as well... the batteries gave just the last 2%.
In my opinion, there are a lot of very important things to get right in any loudspeaker design, fieldcoil or not, before tuning stuff like PSUs, element quality, cabling and so on becomes your playground... (of course this is not intended to suggest that you haven´t the important stuff right already...)
All the best
Mattes
Dear Mr Hentai, Frank40, Gomper (Ken),
I considered it as my birthday present that I found yesterday your thread. Over the last two days I have read all your posts and all your research and development on the topic of field coil loudspeaker from 1st to the last page. For the last couple of years I have been making my own speakers and decided to try to make another project from start to finish, including my own drivers. I have searched and read various sources on this topic for a long time, but I can now confidently say that you, gentlemen, have fit in one place such a volume of information that should be collected for months on the Internet! I'm treated your thread as a one of the best source of knowledge in this area. I take off my hat and express my sincere gratitude and respect to you! Wish you a good luck and success in your future projects!
Best regards,
Roman
I considered it as my birthday present that I found yesterday your thread. Over the last two days I have read all your posts and all your research and development on the topic of field coil loudspeaker from 1st to the last page. For the last couple of years I have been making my own speakers and decided to try to make another project from start to finish, including my own drivers. I have searched and read various sources on this topic for a long time, but I can now confidently say that you, gentlemen, have fit in one place such a volume of information that should be collected for months on the Internet! I'm treated your thread as a one of the best source of knowledge in this area. I take off my hat and express my sincere gratitude and respect to you! Wish you a good luck and success in your future projects!
Best regards,
Roman
membrane segments
Thank you in advance for your comments!
Best regards,
Roman
Hi Ken! May I ask you a question, how did you make the segments for the driver membrane? Did you use something like a Fusion 360 with a splitting the body and transfering it to the plain?
Thank you in advance for your comments!
Best regards,
Roman
Yeah nice first is Im wondering how its sounding silent as it has ripple of 120mv peak to peak as per the data sheet. In that case there are regulators that can be even lower than that ripple level. But yes for the cost that you pay if its still good then thats nice.