For my DIY biamp 6-24 crossover (0;+24V), I used Salas UltraBiB. For the Linkwitz biquad circuit (-12V; 0; +12V), I used a shunt PSU.
The TrueAudio website has a Linkwitz Transform calculator. I used this to get some initial values, and then I fine tuned them with LTspice.
If anyone is interested, I can share my PCB design, but I'll have to remove the component values from the silkscreen layer first.
The TrueAudio website has a Linkwitz Transform calculator. I used this to get some initial values, and then I fine tuned them with LTspice.
If anyone is interested, I can share my PCB design, but I'll have to remove the component values from the silkscreen layer first.
0-100dB on the Y-axis is very forgiving and would make the worst speaker look rather nice. How does it look like with 55-100 dB on the Y-axis?
It is still the worst speaker 🙂 But before the Linkwitz circuit and the DIY biamp 6-24 crossover, it was even worse....
Attached the driver's response mounted into the same baffle. +6dB baffle step rise at 260Hz and drop under 150Hz
So no sub caused a giant peak between 2-7kHz? I wonder that happened.
I read more about the Audionirvana Classic 12 inch woofer - it seems like something I want to try! But I usually prefer compression drivers from at least 500Hz and up.
I read more about the Audionirvana Classic 12 inch woofer - it seems like something I want to try! But I usually prefer compression drivers from at least 500Hz and up.
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I guess the giant peak around 2-7kHz is quite common with large drivers.
My speaker design evolved organically. I began with a large, full-range cabinet, but its bright sound, due to a giant peak, led me to modify it. I added a tweeter with a passive crossover and used this configuration for over a year. Curiosity sparked me to experiment with an 'open baffle' configuration. I just removed the fron from the speaker cabinet first. It was terrible, unbalanced, no bass at all, etc, but there was something special about it. Some magic. Finally, I incorporated a DIY 6-24 crossover with Linkwitz circuit to achieve the best possible sound from this design.
I've attached the gerber files for Linkwitz circuit:
Output coupling capacitor NOT part of the PCB needs to add after. C11 and C33 parallell capacitor with C1 and C3 to set the correct value easily.
Resistor, and capacitors are marked according to TrueAudio's calculator. Capacitors around the Opamp are filter capacitors (optional)
Output coupling capacitor NOT part of the PCB needs to add after. C11 and C33 parallell capacitor with C1 and C3 to set the correct value easily.
Resistor, and capacitors are marked according to TrueAudio's calculator. Capacitors around the Opamp are filter capacitors (optional)
Did you get this sorted? There can be multiple issues here. Over the past six months I’ve hit probably just about every issue possible with this circuit. First thing to check is the jumper connections, or any loose filter caps/resistors. Give them a wiggle or a reseat. Check the gate voltage at the 1K resistor. If it’s reading something very low or high, like 2v or 20 volts, one of the jfets is toast. If it’s the input buffer, sometimes the voltages can be all over the place, but generally the filter voltages here should be between 8-11 volts.
If you need a howto on selecting a jfet, let me know. I’ve been at this for months now 😵
Good news, I received this response from Elena at the diyaudio store:
"Upon checking, we are expecting new stocks for the DIYK-XO624BI (DIY Biamp 6-24 Crossover) in roughly a month or two."
Anyone can recommend an amplifier to build for tweeter?
Currently I'm using EL84 based PP tube amp for midwoofer 20Hz-4kHz range (it's a variant of Baby Huey (12W)), and I'm hooked up an old NAD 3020 for tweeters (4kHz and up)
I'm thinking about some Class A, like JLH or something similar.
Currently I'm using EL84 based PP tube amp for midwoofer 20Hz-4kHz range (it's a variant of Baby Huey (12W)), and I'm hooked up an old NAD 3020 for tweeters (4kHz and up)
I'm thinking about some Class A, like JLH or something similar.
Gaszto: I am using an ACA Mini on the compression driver in a bi-amped system from 1200 hz up. Citation 5 PP tube amp for the woofers in a moderately sized room. The Mini (about 4 watts?) seems to have plenty of power. The kits are available at the DIY Audio Store. Might be a quick way to go Class A for your tweeters.
Hi, thanks for the suggestion, I think the 4W should be enough, but I’m curious about Aleph J
I'm thinking about doing this. What is the supply voltage requirement? Also, what smd caps did you use for the op-amps?
I put 100nF 0805 size ceramic SMD for the Opamp. Since in my configuration the power supply is close to the PCB (about 5-6cm long cable has been used) I put only the 100nF ceramic ones. There is a possibility to add foil cap 100-330nF as well, or 1-4.7uF tantallum SMD on back side. In this sense the PCB is quite universal.
Power supply can be from +/-9V - +/-15V in my case it is +/-11V but higher like 12-15V maybe better. It can be a simple LM317/337, or something more sophisticated. I’ll try how does it affect the sound quality of different power supplies but I think not too much influence.
Power supply can be from +/-9V - +/-15V in my case it is +/-11V but higher like 12-15V maybe better. It can be a simple LM317/337, or something more sophisticated. I’ll try how does it affect the sound quality of different power supplies but I think not too much influence.
It's finally alive. Seems to be playing music OK, although the loudspeakers need to be built, and filter C/R values have yet to be finalised. I do not recommend using LSK170's unless you like pain, or you really know what you are doing. That added months to the project.
