Having an optical splitter which does delay on 1 output so the front amp/speakers can be delayed enough to be in phase with subs on the 2nd output would be super practical. Anyone heard of such device?
The miniDSP company has some products that implement delays along with filters. The Flex can be used for one optical input and two optical outputs with delay that is configurable. You have to select the version that is digital in, digital out when ordering. https://www.minidsp.com/products/minidsp-in-a-box/flex
The cheapest solution would be to use a MediaWorx ADAU1466 board. SigmaDSP can be a little intimidating at first, but it's not that bad once you spend some time with it.
https://www.aliexpress.us/item/2255800804987334.html
Programmer....
https://www.aliexpress.us/item/3256805426472835.html
https://www.aliexpress.us/item/2255800804987334.html
Programmer....
https://www.aliexpress.us/item/3256805426472835.html
Thanks for the link! I didnt see any documentation links so that makes me skeptical. Think a an optical in with 2 out and potmeter for delay would sell like hot cakes! So many have stereo front end amp and a sub slapped on as a afterthought. Having the possibility to delay the fronts would tighten up the upper bass immensly.
What documentation are you referring to? I bought both of those items from those exact sellers. Nothing to be skeptical about.
The board has 1 SPDIF in and 1 SPDIF out. Since you need 2 outputs, you would need to add an l2S to SPIF converter. WM8805 boards on Ali are also fairly cheap. Not sure if it's better to use two of those vs one converter + the native SPDIF output of the 1466.
Using one of the ADC inputs and a pot to adjust the delay is surely doable, but I'm new to using SigmaStudio so can't offer any help on how to configure that. I just have a basic configuration running on mine with Bluetooth via I2S on the input and 3x PCM5102A on the outputs for active 3-way configuration testing.
The board has 1 SPDIF in and 1 SPDIF out. Since you need 2 outputs, you would need to add an l2S to SPIF converter. WM8805 boards on Ali are also fairly cheap. Not sure if it's better to use two of those vs one converter + the native SPDIF output of the 1466.
Using one of the ADC inputs and a pot to adjust the delay is surely doable, but I'm new to using SigmaStudio so can't offer any help on how to configure that. I just have a basic configuration running on mine with Bluetooth via I2S on the input and 3x PCM5102A on the outputs for active 3-way configuration testing.
1. How precise would this pot be?
2. What would the range be?
3. Would there be any indication of the amount of delay applied?
1. No clue
2. 0ms to more than you could possibly ever need for time alignment purposes unless your subwoofer is at the other end of your street (1600ms@48kHz/800ms@96kHz)
4. Not without getting a microcontroller involved
If this was my project, I wouldn't care about external control from a pot/buttons or a display. How often do you need to change the delay that you can't just set/view it from SigmaStudio?
2. 0ms to more than you could possibly ever need for time alignment purposes unless your subwoofer is at the other end of your street (1600ms@48kHz/800ms@96kHz)
4. Not without getting a microcontroller involved
If this was my project, I wouldn't care about external control from a pot/buttons or a display. How often do you need to change the delay that you can't just set/view it from SigmaStudio?
Sure, there are options like the TPA5050, but what is OP supposed to do with an IC? No offense to him, but if he had the ability to design his own board and program a µC to control it, he probably wouldn't have made this thread.
I simply offered a solution of reasonable cost and skill, with the added benefit of having a DSP at his disposal.
I simply offered a solution of reasonable cost and skill, with the added benefit of having a DSP at his disposal.
Thanks for both suggestions. I and most ppl just want a plug and play solution when using optical. I could make my own but that would mean a massive undertaking and a waste of time when I could just get a dsp as mentioned. I think an optical delay board could be made extremely cheap compared to a dsp. Wouldnt it just be holding a signal and delaying it? Im thinking 0-0.5ms at a reasonable resolution with focus on keeping it cheap. There is a ton of people having a 2.1 setup with just an stereo amp. Most people would do an alignment by ear or fire up their phone for db measuring.
I have Umik and Rew so I'd just use that. I would think the first guy making a cheapo board like this in China and put it on Ali would sell a ton of these boards. On my pc I bought an usb to spdif soundcard for 30usd that works perfectly and its just 3x6cm so it hangs off the back of the pc. If a similiar size board could be made it wouldn't add another box in a otherwise clean stereo setup. I think that would appeal to a lot of users.
Thanks for that TPA5050 suggestion but I couldnt find anything interesting products with it. If someone made a board with spdif and chip like it that would useful to a lot of people.
I have Umik and Rew so I'd just use that. I would think the first guy making a cheapo board like this in China and put it on Ali would sell a ton of these boards. On my pc I bought an usb to spdif soundcard for 30usd that works perfectly and its just 3x6cm so it hangs off the back of the pc. If a similiar size board could be made it wouldn't add another box in a otherwise clean stereo setup. I think that would appeal to a lot of users.
Thanks for that TPA5050 suggestion but I couldnt find anything interesting products with it. If someone made a board with spdif and chip like it that would useful to a lot of people.
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Various audio delay devices, both analogue and digital, already exist. Some cheap others expensive. Some just delay while others include delay as one of their many functions.
Weird I've been searching for such a product for several years now and still Google turns up nothing. Using terms like optical/spdif and adjustable delay turns up usally. No usable products turn up searching for tpa5050 either. I saw the tpa5050 were sold as chips or in ready made TV's only.
None of those have sub-millisecond resolution except for possibly the Soniflex, which costs over $2k. They're all meant for audio/video sync, not speaker time alignment.
If you want cheap then you have to compromise or be imaginative. Otherwise get a real loudspeaker management box. Crash course in Sigmastudio not needed.
Thx for the suggestions buy they are either too big or expensive. Maybe someone on this forum needs a winter project 🙂
IMO it sounds trivial until one considers how it could be actually implemented. Unless you used some analog delay line (which would be quite expensive at SPDIF frequencies and very inflexible for delay configuration), you need to recover the clock from the SPDIF stream. That means you would need a full-blown SPDIF receiver. That will provide I2S, i.e. a serial format with separate clock signal. Now you can delay with sample multiples using some FIFO with multiples of frame bitlength - e.g. assuming your SPDIF receiver is configured to output 24-bit I2S, every multiple of 48 serial bits in the FIFO would delay by one sample period. Then SPDIF transmitter behind the FIFO.
Now SPDIF can have various rates, your time calculation would have to account for that.
To configure you would need some user-friendly way to change the FIFO length. USB = additional microprocessor with a firmware to code.
IMO it's much easier to use a full-blown DSP chip, like already mentioned here several times. It would offer much more flexibility.