My Ribbon
Hi,
just want to show you how is made similar dipole Ribbon with double magnets and air gap between them. Magnets are little bit different in size 30x10x5 with magnetization through 10mm also custom made. Magnets are not glued but used special device to mount them together.
Ribbon tape is 5micron. custom ordered. Body is made of black anodized 5mm aluminium. Crossover is adjusted at 1500 Hz and minidsp 2x4HD used.
Hi,
just want to show you how is made similar dipole Ribbon with double magnets and air gap between them. Magnets are little bit different in size 30x10x5 with magnetization through 10mm also custom made. Magnets are not glued but used special device to mount them together.
Ribbon tape is 5micron. custom ordered. Body is made of black anodized 5mm aluminium. Crossover is adjusted at 1500 Hz and minidsp 2x4HD used.
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You can see white plastic 1mm between magnets. Membrane is exactly in the middle of this plastic. Difficult to see on photo.
OK, so not in the centre of the gap - right?
What is the sensitivity? Do you have measurements?
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What is the sensitivity? Do you have measurements?
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Wrong, it is in the center of the gap. I have calibrated microphone but not calibrated sound level. In my DSP level is decreased 4dB. So I assume that sensitivity could be 94dB. Here is youtube link. It is recorded in mono by measurement microphone.
Bookshelf loudspeaker with dipole Ribbon - YouTube
Bookshelf loudspeaker with dipole Ribbon - YouTube
Ok, I understand. Tweeters can be built in many ways!
My picture shows a one-row magnet tweeter with poles pointing to left and right, using the field between. Sounds quite good dispite its looks! The transformer core is from a deceased Quad Els-63.
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Aha - behind that white plastic is also magnets?
Magnets are glued to aluminium I suppose?
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Magnets are glued to aluminium I suppose?
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Can you tell the name of the woofers? The sound in the youtube video is awesome!
I know that judging sound from a video is stupid, but if You have the knack of 40 years of video listening, you can tell if speakers sounds good or not..
I know that judging sound from a video is stupid, but if You have the knack of 40 years of video listening, you can tell if speakers sounds good or not..
I think with this construction you losses sensitivity but front dispersion is better. This core is probably amorphous. I also use amorphous core 6.4
The sensitivity of my tweeter is around 90 dB, but can get to 94 dB with different transformer configuration. Even higher with bigger powerful N52 magnets..
Woofer is ceramic driver from SB-acoustics SB17CAC35-4. Ribbon dipole is sounding so good that can't be compared with anything on the market.
Many things are important to get higher sensitivity. Transformer, magnets, size of ribbon and wire length between transformer and ribbon.
I agree, and in my opinion and experiments, there´s a optimal ribbon lenght also at around 140 to 200 millimeters.
My ribbon is 150x14 mm. In youtube video you can see also my big OB system with ribbon 300x25 mm. Long ribbon is problematic and doesn't keep uniformity. It is supported on the middle.
The ribbons were measured with the same current driving them. You are correct that the response in the 6db/oct portion of the curve is defined by the air load, so same SPL if the driving current, ribbon area, and magnet + support frame is the same. These measurements were made for the purpose of illustrating this behavior. I agree that choice of foil thickness should involve more than just the usual “lighter is better” mantra.
More details here: Post #23
Just for fun, measurements of 0.65µm ribbon here: Post #122
I meant to say this when you posted. That is a thing of beauty! I can only imagine they sound as good as they look. I look forward to seeing your report on performance when finished.
cool design, it used these double magnets with a small space in between them to create a more even and wider fields like the Dahlberg Audio Design one >? believe apogeee used it in there midrange to. its ideal for the type of construction you made with a back plate with magnets and spacer forming sort of one half of the construction. interesting !!
