And they're almost done.
Actively crossed over two ways. The tweeter and mid are passively crossed first order @ 3000 hertz.
The two 10" GRS Polycone woofers are actively crossed at 200 hertz.
Pretty pleased with the finish so far, just walnut oil over dye, I will hopefully receive the beeswax sometime this week to blend with the oil for a polish.
Very little equalizing needed here, I boosted 300 hertz 2 db, and cut 12,000 hertz 3 db, really only need a sub for electronic bass "thump", pleasant sound.
Actively crossed over two ways. The tweeter and mid are passively crossed first order @ 3000 hertz.
The two 10" GRS Polycone woofers are actively crossed at 200 hertz.
Pretty pleased with the finish so far, just walnut oil over dye, I will hopefully receive the beeswax sometime this week to blend with the oil for a polish.
Very little equalizing needed here, I boosted 300 hertz 2 db, and cut 12,000 hertz 3 db, really only need a sub for electronic bass "thump", pleasant sound.
Attachments
Please don't make this a build thread to reduce clutter 🙂. Also why is the image sideways?
Spatial Lumina. Beryllium coax driver!
Spatial Lumina. Beryllium coax driver!
An externally hosted image should be here but it was not working when we last tested it.
Please don't make this a build thread to reduce clutter 🙂. Also why is the image sideways?
Fair enough, and I don't know why the image is sideways.
It was right side up when selected.
Gah - it's terrible! But I like how it sounds, just as ugly as it looks.
My ugly as sin, and likely heretical OB setup. It would need a lot work work, extra tuning with a dsp, for anything serious, but for my little office, it's fun.
I made it from some extra cabinet fronts I had laying around. The 90 degree offset is intentional, I like the response I get from these little cheap speakers.
Even worse is that I have a sub also in the room. But then again, these drivers are not full range, either.
For some reason this thing keeps rotating my pictures.
At least when you click it will open the full image correctly.

My ugly as sin, and likely heretical OB setup. It would need a lot work work, extra tuning with a dsp, for anything serious, but for my little office, it's fun.
I made it from some extra cabinet fronts I had laying around. The 90 degree offset is intentional, I like the response I get from these little cheap speakers.
Even worse is that I have a sub also in the room. But then again, these drivers are not full range, either.
For some reason this thing keeps rotating my pictures.
At least when you click it will open the full image correctly.

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Water based finishes
A simple solution is to give the h20 based finish a couple of days to thoroughly dry and then put one coat of clear shellac over it and then your oil based finish.
A simple solution is to give the h20 based finish a couple of days to thoroughly dry and then put one coat of clear shellac over it and then your oil based finish.
My ugly as sin, and likely heretical OB setup.
After some time listening, repositioning, I've grown pretty fond of this setup. As some others have said before, "Stereo" is an artifact of perception, so I wasn't worried about placing 2 channels like this. They reflect off the room in a pleasant way.
Using others observations, I moved them a minimum of 3 feet from the wall, and it did improve the sound.
I'm making a similar arrangement for a family member and will be giving them a blind listening test before informing them of the good news. A happy day.
Does anyone know the pro and con for this setup with bass-drivers?
Expensive with double up. Is the backfiring drivers in reverse polarity to compensate for baffle step? If yes, how effective is this concept? Kyron claims 20 Hz??? (With AE Dipole 12 drivers)
Expensive with double up. Is the backfiring drivers in reverse polarity to compensate for baffle step? If yes, how effective is this concept? Kyron claims 20 Hz??? (With AE Dipole 12 drivers)

Does anyone know the pro and con for this setup with bass-drivers?
Expensive with double up. Is the backfiring drivers in reverse polarity to compensate for baffle step? If yes, how effective is this concept? Kyron claims 20 Hz??? (With AE Dipole 12 drivers)
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Don't know but I heard these at Hornfest and was blown away.
An externally hosted image should be here but it was not working when we last tested it.
The double sided bass drivers are probably for taking out the forces. This speaker will not vibrate.
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No, it's not for cancelling vibration force.
It's for making the dipole path length larger - increasing the distance of the front/rear wave cancellation.
The air between 2 woofers moves back and forth as a bulk without the behavior of soundwave. So, it should be quiet here. But there could be a weird sense of airflow. No problem in the normal listening position.
If the woofers operate in the same polarity, it'd become a quadrupole. For producing bass, the efficiency is too low.
It's for making the dipole path length larger - increasing the distance of the front/rear wave cancellation.
The air between 2 woofers moves back and forth as a bulk without the behavior of soundwave. So, it should be quiet here. But there could be a weird sense of airflow. No problem in the normal listening position.
If the woofers operate in the same polarity, it'd become a quadrupole. For producing bass, the efficiency is too low.
Probably same principle as Emerald Physics CS-1 prototypes, with 4 15" drivers on each side. As I understand it, rear woofers wired out of phase, but since they are firing rear they will actually be in phase.
Big Reds MarkII.
Had enough wood and parts to do another pair, this time with Alpair 12P's.
Went to a smaller baffle to smooth a 250-300 hertz bump in response mechanically, since my active crossover setup can't "spread" the crossover points further apart.
Had enough wood and parts to do another pair, this time with Alpair 12P's.
Went to a smaller baffle to smooth a 250-300 hertz bump in response mechanically, since my active crossover setup can't "spread" the crossover points further apart.
Attachments
No, it's not for cancelling vibration force.
It's for making the dipole path length larger - increasing the distance of the front/rear wave cancellation.
The air between 2 woofers moves back and forth as a bulk without the behavior of soundwave. So, it should be quiet here. But there could be a weird sense of airflow. No problem in the normal listening position.
If the woofers operate in the same polarity, it'd become a quadrupole. For producing bass, the efficiency is too low.
Is that the principle in some the Legacy Audio speakers I've seen?
I thought it was to take a little pressure off the woofers surface, as two motors would manage the same "air sandwich".
Widening the null makes more sense.
It's pretty accurate for a fullrange driver without any eq in a large room. The chart is only for on axis frequency response though and does not take any power repsonse in account.
That's been around 🙂Can anyone confirm the accuracy of this chart? Thanks!
'Width' would be more apropos than 'length'
Depends on what "needed" means.
With no EQ and baffle on floor:
If Fs = 100Hz with Qts = 2 then
a 2 ' baffle gives flat down to 100 Hz
If Fs = 100Hz with Qts = 1 then
4 ' is needed
Fs = 50Hz and Qts = 2 then
4 ' will go down to 50 Hz
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