Thank you Boden! Adding those components to my shopping cart and Vitiux CAD looks like another tool I'll want to learn!
Out of pocket for the next day with family commitments and the crazy Halloween festivities here in the US, but will get those raw measurements day after tomorrow.
I'll need more op amps, so thinking I'll order a number of OPA 1652/1654s in order to match the other driver filters and be able to try out the different topologies here. If there's a better recommendation such as the OPA1644 JFETs (or perhaps worse due to the triode like rolloff?) I'd love to hear recommendations. Sooo many to choose from.
Truly appreciate everyone's contributions!
In answering your questions:
Well, programming a DSP requires a computer. Once final configuration is found, only the DSP (e.g. miniDSP) remains in the chain. I personally find complexity of x-over design comparable between analog and DSP. But the flexibility and speed of DSP development are faster in my experience.
miniDSP products do the digital signal processing for filters and x-overs, not analog... In several of their products DACs are built in, some have digital outputs and need external DACs.
Greetings,
Winfried
Ive had to take a pause, but wanted to give an update, since I’ve been given such generous guidance from members of this forum. I had to concentrate on other things and step away for a bit and am now overseas until January.
It took a while, but I did hear back from Mark at xkitz for the questions posed and unfortunately, no other slopes are available at this time.
Looks like I’ll have ample time to begin to digest the linkwitz lab and diy sites in the meantime and look forward to resuming again when I’m back in country.
Sam
It took a while, but I did hear back from Mark at xkitz for the questions posed and unfortunately, no other slopes are available at this time.
Looks like I’ll have ample time to begin to digest the linkwitz lab and diy sites in the meantime and look forward to resuming again when I’m back in country.
Sam
Finally getting back to this after a long while and I'm happy to say problem resolved.
Not sure exactly what was wrong, but I wasn't getting unity gain on the EQ, which was previously hooked up to the external processor loop of the technics su-9070 pre-amp, and was about 6-10db down. I decided to pull the EQ and put a tone through it to a scope and then compared the tone directly fed to the scope, and was surprised to see that it was, indeed, giving unity gain.
Not sure if there's a problem with the preamp's loop, solder joint fractures, or I had the EQs mic-volume in the wrong position (impacts gain for some reason) or maybe connected incorrectly, but I decided to try the EQ between the pre-amp and the crossover and the three band parametric adjustment made it easy to dial for exactly the sound I was after since I could adjust Q and gain at the given frequency among the 14 bands. (though q just has 2 settings, narrow or wide)
They were +2db at 40hz and +4db at 63hz with wide peaks, and a narrow +2db at 10khz, after first level matching the altec 14 cabinet's 2 drivers using sweeps. Different than what I was going for, but the knob that allows sweeping the peaks up and down across the frequency bands made it easy to pinpoint holes in the sound and and trying out narrow or wide slopes on just 3 points made things easy.
Relieved that my EQ is working and finally happy with how these speakers sound and that unnecessary ADC/DAC conversions from the previous crossover (driverack pa2) are no longer in the chain. I did lose the ability to adjust delay, but that doesn't seem to be a problem in my small room.
Thanks all for the help along the way. I'll take some final measurements at some point, out of curiosity, to see what the final curve looks like.
Not sure exactly what was wrong, but I wasn't getting unity gain on the EQ, which was previously hooked up to the external processor loop of the technics su-9070 pre-amp, and was about 6-10db down. I decided to pull the EQ and put a tone through it to a scope and then compared the tone directly fed to the scope, and was surprised to see that it was, indeed, giving unity gain.
Not sure if there's a problem with the preamp's loop, solder joint fractures, or I had the EQs mic-volume in the wrong position (impacts gain for some reason) or maybe connected incorrectly, but I decided to try the EQ between the pre-amp and the crossover and the three band parametric adjustment made it easy to dial for exactly the sound I was after since I could adjust Q and gain at the given frequency among the 14 bands. (though q just has 2 settings, narrow or wide)
They were +2db at 40hz and +4db at 63hz with wide peaks, and a narrow +2db at 10khz, after first level matching the altec 14 cabinet's 2 drivers using sweeps. Different than what I was going for, but the knob that allows sweeping the peaks up and down across the frequency bands made it easy to pinpoint holes in the sound and and trying out narrow or wide slopes on just 3 points made things easy.
Relieved that my EQ is working and finally happy with how these speakers sound and that unnecessary ADC/DAC conversions from the previous crossover (driverack pa2) are no longer in the chain. I did lose the ability to adjust delay, but that doesn't seem to be a problem in my small room.
Thanks all for the help along the way. I'll take some final measurements at some point, out of curiosity, to see what the final curve looks like.