Very very nice Frank. Glad to see your enjoying it.
@ Jef
Yes, but i've been pretty busy here as the spider concept and field coil motors caught the attention of audio people and i had a few queries but im glad to see it stirs the interest so much.
I have removed the phase plugs on the mid bass and replaced them with dust caps just to see the difference. Sure enough high frequency extension dropped to 4K. havent measured yet the directivity influence but i placed it in the vented test enclosure and crossed it at 2K (acoustic) to a comp driver. I recorded the sound with an ECM 8000 to eliminate the crappy mic on my crappy camera
In the youtube link you can hear it. Recording is mono and that room is quite lively and noisy.
Also in parallel im doing the field coil comp driver. The phase plug i made presents an interesting feature i always wondered about but i have to find the time to write a good post about it.
At this point im please with the field coil structure and spider. At 12 inch i got passed 10kHz but to reach the next octave requires a lot of effort (and budget) for cones. But this is just a personal spec i set as i like most the sound coming from large radiating surfaces. It really brings out the meat of the instrument. I like power and dynamics.
Thats why im pleased Frank found dynamics to be good. It is one of the traits of a strong motor.
I will return with more stuff soon.
[Project Ryu] Field Coil MidBass driver with dustcap in vented box - YouTube
@ Jef
Yes, but i've been pretty busy here as the spider concept and field coil motors caught the attention of audio people and i had a few queries but im glad to see it stirs the interest so much.
I have removed the phase plugs on the mid bass and replaced them with dust caps just to see the difference. Sure enough high frequency extension dropped to 4K. havent measured yet the directivity influence but i placed it in the vented test enclosure and crossed it at 2K (acoustic) to a comp driver. I recorded the sound with an ECM 8000 to eliminate the crappy mic on my crappy camera
In the youtube link you can hear it. Recording is mono and that room is quite lively and noisy.
Also in parallel im doing the field coil comp driver. The phase plug i made presents an interesting feature i always wondered about but i have to find the time to write a good post about it.
At this point im please with the field coil structure and spider. At 12 inch i got passed 10kHz but to reach the next octave requires a lot of effort (and budget) for cones. But this is just a personal spec i set as i like most the sound coming from large radiating surfaces. It really brings out the meat of the instrument. I like power and dynamics.
Thats why im pleased Frank found dynamics to be good. It is one of the traits of a strong motor.
I will return with more stuff soon.
[Project Ryu] Field Coil MidBass driver with dustcap in vented box - YouTube
Frank, how is the sound stage and image and how wide the sweet spot. I wonder if they are similar to dual concentric driver speakers with this design.
Hi,
@ 454Casull, I did try out some other spiders, but I need a very high compliance to reach a low resonant frequency.
@ speedlees, Here is some link to where I got some building parts from. Audio Parts - Index and Audio & Video - Audio Components - Speaker Replacement Parts - MAT Electronics Mat-electronics take forever to deliver but has nice prices. The most expensive part is the field coils, you need to talk to Hentai.
@ Jef Nuyts, I don't have the right test equipment to measure the parameters, but I hope that I will get some in the future.
@ magi44ken, the sound stage and image is some of the best I ever had, with the right recordings. The speaker can disappear leaving a big and beep holographic sound picture, and it is easy to pinpoint all instruments and voices. The sweet point is not very large but not at all small, but I think it is smaller than dual concentric driver speakers.
@ Hentai, Nice video, looks like a set of nice speaker you go there.
Take care
@ 454Casull, I did try out some other spiders, but I need a very high compliance to reach a low resonant frequency.
@ speedlees, Here is some link to where I got some building parts from. Audio Parts - Index and Audio & Video - Audio Components - Speaker Replacement Parts - MAT Electronics Mat-electronics take forever to deliver but has nice prices. The most expensive part is the field coils, you need to talk to Hentai.
@ Jef Nuyts, I don't have the right test equipment to measure the parameters, but I hope that I will get some in the future.
@ magi44ken, the sound stage and image is some of the best I ever had, with the right recordings. The speaker can disappear leaving a big and beep holographic sound picture, and it is easy to pinpoint all instruments and voices. The sweet point is not very large but not at all small, but I think it is smaller than dual concentric driver speakers.
@ Hentai, Nice video, looks like a set of nice speaker you go there.
Take care
Frank glad you like them.
The 6 yellow ones in the picture are Frank's.
Well i guess we could start a group buy if there is interest im up for it. Motors, Spiders, Phase plugs, Complete Units...
Who else would be interested in group buy?
If more are interested i will make a list of parts and cost.
The 6 yellow ones in the picture are Frank's.
Well i guess we could start a group buy if there is interest im up for it. Motors, Spiders, Phase plugs, Complete Units...
Who else would be interested in group buy?
If more are interested i will make a list of parts and cost.
You can use them in OB indeed. I have actually done such, you can always modify field coil current/voltage to adjust Q but if you are set for such an application then i suggest leaving the motor feed as high as possible and use a voice coil with small wire diameter low number of turns to raise Q. You can get a nice small height voice coil great for underhung and a Q of 0.8-1 but with the force coming from magnetic circuit.
I made one and you can feel the roundness of bass even in open air. I think i still got that cone and voice coil, i will assemble it this weekend and try a recording.
I made one and you can feel the roundness of bass even in open air. I think i still got that cone and voice coil, i will assemble it this weekend and try a recording.
Hi Folks,
Some progress with the EM suspension speaker. (without spider)
Here are some pics of it. Did listen to it (open baffle) by ear but doesn't say much. Within a few weeks I send the specs of it. Question to Hentai, wich tool do you use for measuring the small thiel parameters? There are a few like woofer 2 pro or daytona but i want to test not only with small currents but also large. This is important to test the suspension on its whole range.
The basket is only for test purposes, it is possible to change the height and diameter for testing.
How do you insert tumbnails?
Take care,
Some progress with the EM suspension speaker. (without spider)
Here are some pics of it. Did listen to it (open baffle) by ear but doesn't say much. Within a few weeks I send the specs of it. Question to Hentai, wich tool do you use for measuring the small thiel parameters? There are a few like woofer 2 pro or daytona but i want to test not only with small currents but also large. This is important to test the suspension on its whole range.
The basket is only for test purposes, it is possible to change the height and diameter for testing.
How do you insert tumbnails?
Take care,
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@Frank Yes the speaker is fully functional and sounds good but paper cone is really on my wish list. First i tested with copper wire but it was to heavy because i have more then one winding. (oke no spider and within some time no surround so this is also weight reduction) but not good enough. The one I use right now is alu wire (parallel winding, wire 0.20mm) Re of 4.5ohm. What i already can tell is the good sensitivity, much better then my keff q75 speakers. B of the magnetic gap is 1.5T not bad and BL is 10NA. Xmax linair 8mm. Q, Fs, etc... I have to measure.
Find out (the phaseplug wasn't made yet):
Prototype mid bass dualcoil speaker with adjustable electromagnetic suspension - YouTube
Keep you posted
Find out (the phaseplug wasn't made yet):
Prototype mid bass dualcoil speaker with adjustable electromagnetic suspension - YouTube
Keep you posted
Awesome speaker Jef. Congrats.
Pretty good bass i get from the video. Nice.
T/S i use WT3 and/or LIMP. With the later you can use a power amp for higher current but you need to make a little test rig. WT3 is very fast to get a impedance curve tho.
I assembled the cone for OB. Im waiting for glue to set in and will get it running pretty soon.
Pretty good bass i get from the video. Nice.
T/S i use WT3 and/or LIMP. With the later you can use a power amp for higher current but you need to make a little test rig. WT3 is very fast to get a impedance curve tho.
I assembled the cone for OB. Im waiting for glue to set in and will get it running pretty soon.