interesting assertion - even studio quality ADC/DAC, DSP used to create the vast majority of commercial music released in the last 20+ years?
or are you saying that since the music already went through these steps the 'problem" is only when you see the processor in your system?
if you need 10s of ms of delay, phase controlled over 3 decades of frequency then there really is no practical options except converting analog electrical signals to another medium where the signal delay can be done and then reconverting back to analog electrical signal
it just happens that audio ADC/DAC/DSP are the most developed, highest performing, and cheapest option today
Yes but with problems.
Be sure to read the entire article.
https://www.dfad.com.au/links/DFAD_PASSIVE_SURROUND.pdf
Be sure to read the entire article.
https://www.dfad.com.au/links/DFAD_PASSIVE_SURROUND.pdf
Use a Bucket Brigade, but to be honest I think you would prefer the Digital results.....
Technically an A/D-> FIFO memory -> D/A would provide a delay and doesn't use DSP.
Getting a 1mS delay only at low freqs isn't a big problem - 1mS for a 250Hz waveform is only a quarter cycle, so 90degrees. An allpass can handle that, single opamp.
I rather suspect that what you need though is that delay applied to your mid/HF which realistically is only going to be a goer digitally. What are you using for your source incidentally? Is it digital?
I rather suspect that what you need though is that delay applied to your mid/HF which realistically is only going to be a goer digitally. What are you using for your source incidentally? Is it digital?
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speaker level All pass filter?
You are correct, I need to delay my mid and high horns, in relation to my very large midbass horn.
Source -- analogue only (vinyl).
You are correct, I need to delay my mid and high horns, in relation to my very large midbass horn.
Source -- analogue only (vinyl).
Looks like you'll need to invest in a decent-sounding ADC and DAC chain then. Probably not easy to find off the shelf, but hey this is DIY
<edit> Incidentally its not DSP which is the enemy of good (meaning digital with all the good qualities of analog and none of the bad) sound, rather lousy DACs and ADCs.
<edit> Incidentally its not DSP which is the enemy of good (meaning digital with all the good qualities of analog and none of the bad) sound, rather lousy DACs and ADCs.
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Yes, I can't remember all the details, so here's some info:
www.rhombus-ind.com/dlcat/app1_pas.pdf
www.rhombus-ind.com/app-note/passive.pdf
LC delay lines were used in Hammond organs for the vibrato/chorus effects. They used 16 sections for a bit over 1mS delay but only about 5KHz bandwidth.
Tannoy made a passive time delay for their dual concentrics , called "Sync Source" . 4 capacitors and 4 air coils . there is a lot on the net about it , including schematics and formulas .
I made a couple and have the Eagle files if you need them .
Cheers ,
Rens
Attachments
We would need to know over which frequency range the delay has to be constant. If it needs to be constant up to 20 kHz then an analog dely is theoretiucally feasible but at the cost of a huge component count leading to a lot of noise and distortion.
If the delay only needs to be constant slightly higher than the low-mid crossover frequency then it would be perfectly feasible in an analog way.
Regards
Charles
If the delay only needs to be constant slightly higher than the low-mid crossover frequency then it would be perfectly feasible in an analog way.
Regards
Charles
Hi, yes it is actually possible, with All Pass Filters
I looked at doing this to remove the cycle phase offset in a fourth order active XO. I needed a 6th Allpass to to it. If not more.
Technically an A/D-> FIFO memory -> D/A would provide a delay and doesn't use DSP.
The ADC --> FIFO --> DAC option sounds interesting..... Any recommendations for the ADC and DAC ?
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