That’s a Vishay MKP box cap. Typically used as switching PSU output filter cap for low ESR. This one is 50uF and 500v rated. It’s the mother of all box caps.
I set up the speakers in a larger different room to test the sound. It still sounds great. Amazing bass. No subwoofer needed.
This is setup outside in the exercise room/dance studio area.
I’m using a SMSL Sanskrit 10 DAC, LSA HyperDrive-2 preamp, LSA Warp-1 power amp, 12 gauge speaker cables, and the new crossovers. Source is Amazon HD music streaming. Mostly UHD tracks. The sound is amazing.
I set up the speakers in a larger different room to test the sound. It still sounds great. Amazing bass. No subwoofer needed.
This is setup outside in the exercise room/dance studio area.
I’m using a SMSL Sanskrit 10 DAC, LSA HyperDrive-2 preamp, LSA Warp-1 power amp, 12 gauge speaker cables, and the new crossovers. Source is Amazon HD music streaming. Mostly UHD tracks. The sound is amazing.
A bit bigger but what do you think of the SBA
BIANCO-12OB150-01
for the midrange? It goes pretty low so would help if you wanted to use bigger diameter woofers.
On Mouser, there are two versions, one at $9, the other at $24... which one is it? Thanks!
Is that driver designed for covering the upper midrange?
The IEC baffle cant be blamed:
12in is too big for a SLOB imo. Chamber depth would only allow upper bandwidth of 150Hz.
As a mid it doesn’t go high enough.
You are going to have to restock your on hand spare parts bin and get a color-matched coil. =)$9 one.
Were all of the resistors needed or was your build based on the available in house stock ?
Which drivers needed the most padding (the woofers) ?
My in house stock is my “XO Development Kit” contains almost every typical value of resistor, cap, and inductor needed to make 95% of any crossover I can dream up. I spent about $220 and got most of it to start out and added on over the last couple of years.
10W Resistors to have on hand (4-6 ea): 0.22R, 0.33R, 0.51R, 1R, 1.5R, 2.2R, 2.7R, 3.3R, 4.7R, 5.1R, 7R, 10R, 12.5R, 20R, 30R, 100R, 200R.
Caps all film (2-5 each) : 0.1uF, 0.47uF, 0.56uF, 1uF, 2.2uF, 3.3uF, 4.7uF, 5.0uF, 5.6uF, 6.8uF, 10uF, 15uF, 22uF, 27uF, 30uF, 47uF, 50uF, 60uF, 120uF.
Caps bipolar (4ea): 50uF, 100uF.
Inductors air core (2 ea, some 4): 0.05mH, 0.1mH, 0.2mH, 0.33mH, 0.5mH, 0.68mH, 1mH, 1.5mH, 2.0mH, 3mH, 4mH, 5mH.
Inductors iron core: 0.68mH(2), 1mH (2), 1.2mH(2), 2mH (2), 3mH(2), 4mH(2), 5mH(2), 10mH(2).
Plus a big bag of Wago snap connectors good for 30A. 2,3,5 pins.
It’s nice because I can build in about 15 minutes, any crossover I need so that I can listen to it right away to verify the circuit and fine tune the voicing. I’ll then order replacements and add a few values that might have been missing. I was short a 0.5mH 18ga air core this time. But had 20ga on hand.
Here is the Kit - two Plano boxes worth.
Because the woofers are so darn efficient at 91dB, the midrange needed the most to get it down from 95dB to 91dB. The tweeter is nominally 92-94dB so was very minor. This is not one of those speakers where the tweeter needs 15ohms of padding. I used under 5ohms.
10W Resistors to have on hand (4-6 ea): 0.22R, 0.33R, 0.51R, 1R, 1.5R, 2.2R, 2.7R, 3.3R, 4.7R, 5.1R, 7R, 10R, 12.5R, 20R, 30R, 100R, 200R.
Caps all film (2-5 each) : 0.1uF, 0.47uF, 0.56uF, 1uF, 2.2uF, 3.3uF, 4.7uF, 5.0uF, 5.6uF, 6.8uF, 10uF, 15uF, 22uF, 27uF, 30uF, 47uF, 50uF, 60uF, 120uF.
Caps bipolar (4ea): 50uF, 100uF.
Inductors air core (2 ea, some 4): 0.05mH, 0.1mH, 0.2mH, 0.33mH, 0.5mH, 0.68mH, 1mH, 1.5mH, 2.0mH, 3mH, 4mH, 5mH.
Inductors iron core: 0.68mH(2), 1mH (2), 1.2mH(2), 2mH (2), 3mH(2), 4mH(2), 5mH(2), 10mH(2).
Plus a big bag of Wago snap connectors good for 30A. 2,3,5 pins.
It’s nice because I can build in about 15 minutes, any crossover I need so that I can listen to it right away to verify the circuit and fine tune the voicing. I’ll then order replacements and add a few values that might have been missing. I was short a 0.5mH 18ga air core this time. But had 20ga on hand.
Here is the Kit - two Plano boxes worth.
Because the woofers are so darn efficient at 91dB, the midrange needed the most to get it down from 95dB to 91dB. The tweeter is nominally 92-94dB so was very minor. This is not one of those speakers where the tweeter needs 15ohms of padding. I used under 5ohms.
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I would recommend the PRV 5MR450NDY as the mid driver. What you need is a good low distortion high SPL wide band midrange. The 6FE100 is a good choice for a budget build but the stamped frame and lower tech motor has some distortion artifacts at 1kHz. It’s in the -45dB range but that’s too much for me.
I have tried the B&C 6MDN44 as the mid and it had a bit more distortion than I would have liked which was surprising. It has a basket and motor shape very similar the the next driver - and I have not tried it yet, might be the Faital Pro 6PR160, a cast frame neodymium motor midrange. The spec sheet shows a very smooth flat bandwidth. The distortion is unknown until tested though. It might need a notch at 6kHz though. Whereas the PRV doesn’t have a breakup until 8kHz.
Here was my open baffle measurement of the 5MR450NDY from years ago:
Here is factory response of 6PR160:
For the woofers, since there are 16 of them, going with budget drivers is perfectly adequate and gives amazing bass. However, if someone wants to try lowering bass response Fs and distortion. Maybe a cast frame driver with quality motor would work better. Six RS225-8 8in woofers would have 30Hz response and lower distortion. The sensitivity of 3x parallel and 2x series would be pretty good and be 5.3ohms nominal. Upper bandwidth would be 350Hz (deeper chamber) and still very doable as a crossover point. The cost of woofers would be about $900, but put into perspective, not bad for an ultimate speaker setup. Recall Purifi 6.5 drivers are almost half of that for just one.
There are certainly other woofer choices available. But to get started to see if you like it, it wouldn’t be a bad idea to use cheap woofers first. Make sure the cutouts are big enough to upgrade to cast crane woofers and try them next if you like what you hear.
Ad far as the tweeter goes, I’m not sure it needs to be a dipole and maybe a nice dome would work just fine. They are typically in the 92dB to 94dB range so perfect match in sensitivity. But dipole AMTs would be an excellent choice. Like a Beyma TPL150. Or a Heil. One could make the woofer a modular box and then a tube frame above it to suspend open air mid and tweeters. This supposedly has better imaging and makes the speaker “disappear”.
I have tried the B&C 6MDN44 as the mid and it had a bit more distortion than I would have liked which was surprising. It has a basket and motor shape very similar the the next driver - and I have not tried it yet, might be the Faital Pro 6PR160, a cast frame neodymium motor midrange. The spec sheet shows a very smooth flat bandwidth. The distortion is unknown until tested though. It might need a notch at 6kHz though. Whereas the PRV doesn’t have a breakup until 8kHz.
Here was my open baffle measurement of the 5MR450NDY from years ago:
Here is factory response of 6PR160:
For the woofers, since there are 16 of them, going with budget drivers is perfectly adequate and gives amazing bass. However, if someone wants to try lowering bass response Fs and distortion. Maybe a cast frame driver with quality motor would work better. Six RS225-8 8in woofers would have 30Hz response and lower distortion. The sensitivity of 3x parallel and 2x series would be pretty good and be 5.3ohms nominal. Upper bandwidth would be 350Hz (deeper chamber) and still very doable as a crossover point. The cost of woofers would be about $900, but put into perspective, not bad for an ultimate speaker setup. Recall Purifi 6.5 drivers are almost half of that for just one.
There are certainly other woofer choices available. But to get started to see if you like it, it wouldn’t be a bad idea to use cheap woofers first. Make sure the cutouts are big enough to upgrade to cast crane woofers and try them next if you like what you hear.
Ad far as the tweeter goes, I’m not sure it needs to be a dipole and maybe a nice dome would work just fine. They are typically in the 92dB to 94dB range so perfect match in sensitivity. But dipole AMTs would be an excellent choice. Like a Beyma TPL150. Or a Heil. One could make the woofer a modular box and then a tube frame above it to suspend open air mid and tweeters. This supposedly has better imaging and makes the speaker “disappear”.
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Hi X,
After watching your FAST speaker development, I've been hoping you'd set your sights on open baffle again! I'm tired of having to use subs with my OBs. These look great. How far do you have these from the walls? Some folks insist that the big 15" woofers need a few feet from the rear wall. I wonder if you get a little more flexibility with room placement by having rear output from only the mid and tweeter.
Edit: After looking back at your build photos, I see that the woofers are open to the rear after all. I'm still curious to know what you find in terms of speaker placement and room interaction.
After watching your FAST speaker development, I've been hoping you'd set your sights on open baffle again! I'm tired of having to use subs with my OBs. These look great. How far do you have these from the walls? Some folks insist that the big 15" woofers need a few feet from the rear wall. I wonder if you get a little more flexibility with room placement by having rear output from only the mid and tweeter.
Edit: After looking back at your build photos, I see that the woofers are open to the rear after all. I'm still curious to know what you find in terms of speaker placement and room interaction.
I have TPL-150H with open back in an active setup directly connected to a 45-type SET. I love it! The tweeter is over 102dB sensitivity so the 2W are plenty. I love these open back.
Someone mentioned dipole was important up to about 7kHz.
Thanks, Adason. Yes, when I hardwire solder the XO, the fat lady has sung.
With the EP600 amp with hybrid tube buffer and IcePower 1200AS2 module core, I am only playing 6vrms but the dynamics are insane. Getting 98dB at listening position and fully clean sound.
Those TPL150’s are awesome. A friend made some tractrix synergies with them and SBA 8in woofers.
The PRV is something special. It has an extraordinary high Qms at 20.74. Is that something you think you can hear in the quality of the mids?