Interesting thanks, I think I will start saving too, speakers in rooms seem to be fundamentally flawed 😉
Why not just measure the drivers with one of these? And then you can measure with a microphone circa $100. You'll have a pretty good idea how to adjust whatever SP stuff you have. Yes it's work, but it's the point to pay off using bi-amp and SP.
Destroyer -- I have a EMU 0404 and a ECM8000 already, so I'm good. I'm designing around a Tinker Board for DSP.
My response was in light of your comment about using DSP and being shut out of the newer ESS DACs, which is not the case at all.
My response was in light of your comment about using DSP and being shut out of the newer ESS DACs, which is not the case at all.
For the original capsule design, sure. That can't translate given it was designed for microscopic excursions. But with a complete redesign of the electrodes forming the two capacitors it looks doable to me.
Yup miniDSP 4x10HD. had input switching, will do RIAA and crossover and has a volume knob. Replaces preamp
As Scott and George have proved miniDSP is more than good enough for vinyl
Yeah but that would be another n years before I got something working and the WAF might still be low. MiniDSP is acceptable!
One of my requirements is that I don't need a PC running to listen to music, so whilst miniDSP is missing a number of nice to haves it most closely matches my use case.
For on the fly tone controls I'm still searching. Behringer stuff is nice but the UI is less than friendly.
I understand but the scaling is large, IIRC those are 12mm or so capsules and the area needs to scale roughly by the excursion to maintain sensitivity. Now you have the problem of maintaining the RF Q and abiding by standards of emissions. I see it as a difficult project while the IC accelerometers keep getting better.
I always wondered if sensing (very) near field pressure could work (IC barometers are DC).
Now that we have all figured out why my Re feedback reduces thd at resonance by 50% ---- ?? --->
How well has the dual voice coil worked -- using one coil for correction/feedback/pickup? Some shaping may be needed but not too complicated IMO.
THx-RNMarsh
How well has the dual voice coil worked -- using one coil for correction/feedback/pickup? Some shaping may be needed but not too complicated IMO.
THx-RNMarsh
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One coil for sensing ..... But not for correction ....
It's output is fed back to the channel that drives
the other coil .....
It's output is fed back to the channel that drives
the other coil .....
There is straight magnetic coupling between the two coils, thus cross talk.
One has to check for the amount of cross talk on the driver he has.
George
One has to check for the amount of cross talk on the driver he has.
George
And on a quite different track I need to build a sensor to tell when the 55 gallon drum on my dust collector is full.
The bin sits in a shed outside my shop. The building inspector when we built the shed wouldn't accept a hinged roof and in fact rejected a letter from my structural liscensed profesional engineer as to the shed's construction adequacy. He insisted on stamped drawings by an architect. So we screwed a board across the doorway as if we quit.
The local municipality has since gone back to the old building inspector who is much more reasonable. So it is time to put in a door. Not quite so simple. The door must be locked except when the dust collector is on. Then it should be able to easily swing open if the dust collector burps. The last one was inside the wood shop and one fellow accidentally cut a panel with a nail in it.
As that collector used a cloth bag it caught on fire. Another fellow watching started looking for a fire extinguisher. He did not notice the sign and unit right behind his back. The guilty party turned off the dust collector reducing the fire to a smoldering one and the wheeled the entire unit outside.
In addition to fire extinguishers around the shop we also have a fire hose in the wood shop.
So it became clear the dust collector neede to move outside. Although it is still possible for the connecting duct work to explode. But that doesn't really need a sensor. The duct is 7" sheet metal steel pipe.
Now to sense the dust in the bin first thought would be a photo electric sensor. However with the amount of dust they frequently clog and give false readings.
Next up a limit switch. Typical for liquids is a float switch. Again not quite right.
So the solution seems to be an acoustic method.
One sensor to tell when the bin is full and another to cut power when things get unhappy.
The other project is to mount an accelerometer on various bit of machinery to shut off power when the vibration signature says something is wrong.
So I have an idea of how to make a full bin sensor, but am open to suggestions.
The bin sits in a shed outside my shop. The building inspector when we built the shed wouldn't accept a hinged roof and in fact rejected a letter from my structural liscensed profesional engineer as to the shed's construction adequacy. He insisted on stamped drawings by an architect. So we screwed a board across the doorway as if we quit.
The local municipality has since gone back to the old building inspector who is much more reasonable. So it is time to put in a door. Not quite so simple. The door must be locked except when the dust collector is on. Then it should be able to easily swing open if the dust collector burps. The last one was inside the wood shop and one fellow accidentally cut a panel with a nail in it.
As that collector used a cloth bag it caught on fire. Another fellow watching started looking for a fire extinguisher. He did not notice the sign and unit right behind his back. The guilty party turned off the dust collector reducing the fire to a smoldering one and the wheeled the entire unit outside.
In addition to fire extinguishers around the shop we also have a fire hose in the wood shop.
So it became clear the dust collector neede to move outside. Although it is still possible for the connecting duct work to explode. But that doesn't really need a sensor. The duct is 7" sheet metal steel pipe.
Now to sense the dust in the bin first thought would be a photo electric sensor. However with the amount of dust they frequently clog and give false readings.
Next up a limit switch. Typical for liquids is a float switch. Again not quite right.
So the solution seems to be an acoustic method.
One sensor to tell when the bin is full and another to cut power when things get unhappy.
The other project is to mount an accelerometer on various bit of machinery to shut off power when the vibration signature says something is wrong.
So I have an idea of how to make a full bin sensor, but am open to suggestions.
This must be a problem every woodworking shop has these days? (or custard factory). I went to school near the birds custard* factory, which at one stage had gone bang in a fairly spectacular way when a hopper broke.
*Note english custard and creme anglaise are very different although both referred to outside UK as 'custard'.
*Note english custard and creme anglaise are very different although both referred to outside UK as 'custard'.
The concrete grain silos near the waterfront (and flour mill) here had an issue a few years ago which involved a spark and a large space filled with grain dust suspended in air. I don't think there were any fatalities, but it made an awful mess. Coal dust is only slightly worse (cf Westray mine disaster).
With dual vc, how are they wound?
One in front, one in back? Or one outer, one inner?
If the fb coil couples, game over. If it simply duplicates the BL distortion, game over.
However, if you make a pair of dipole coils, drive them in series, you can monitor the center tap to determine position in the gap.
That might prove too much mass imbalance.....
Wrap two full racetrack coils, front and back,drive u/s, look at the symmetry. That looks more promising.
Jn
One in front, one in back? Or one outer, one inner?
If the fb coil couples, game over. If it simply duplicates the BL distortion, game over.
However, if you make a pair of dipole coils, drive them in series, you can monitor the center tap to determine position in the gap.
That might prove too much mass imbalance.....
Wrap two full racetrack coils, front and back,drive u/s, look at the symmetry. That looks more promising.
Jn
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Dual coil woofers take a hit in sensitivity. You lose that space for the actual motor part of the woofer. I'd rather sense it in a different way - or say to heck with it and go old school without a servo.
With regard to the dust collection, can you do this by weight? It seems to me that it doesn't have to be exact and nearly full is as good as full. It should be pretty easy to calibrate using a strain gauge in a bridge configuration. Not that you would know anything about that. 🙂
-Chris
With regard to the dust collection, can you do this by weight? It seems to me that it doesn't have to be exact and nearly full is as good as full. It should be pretty easy to calibrate using a strain gauge in a bridge configuration. Not that you would know anything about that. 🙂
-Chris
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