In answer to your question, miniDSP current board with only 2xin, 4xout will most likely stay 48kHz, since 96k would mean halving the processing power. It would limit the potential of the board quite a lot and we don't think that it's actually worth it.
Future upcoming platforms will indeed leverage bigger processors, more in&out, but it would also mean more expensive platforms..
Core of the first boards of the miniDSP project was to get a low cost, yet flexible DIY DSP kit out there.
As for the debate between an analog path with a very good DAC (e.g. WM8740 which we like very much) vs digital path, I don't know if we want to get into that argument since these are so different. Both worlds have some strong advantages, it really depends of your needs. THD and SNR figures and noise immunity (using digital vs analog cable prone to RFI) you'll achieve with a digital path will not be possible with analog, no matter how good your DAC IC is. Even we had some very good ADC to accept your WM8740 output, I don't believe it's a good idea to convert back and forth a signal. Best to only convert to analog once.
Maybe your solution would be SPDIF out from your AVR, into a miniDSP via miniDIGI. SPDIF out from the miniDIGI after processing going back to your AVR. Then leveraging your very good on board DAC (WM8740) for analog out. Staying digital all the way, I really doubt that you'll be able to hear any impact on the audio quality...
My 2cts , hope this helps,
Thanks for the detailed response...great info.
Unfortunately, the SC-05 is very rigid in its applications. I don't think it will support looping SPDIF out and back in. As best as I can tell, it only has one level of external source selection from primary inputs to power amp outs. Even if I use its analog pre-outs for the miniDSP, there is no way to get back in to use its power amps.
Thanks,
Darrell
In answer to your question, we indeed plan to have FIR added to our platform one day. When, really depends on our already busy schedule. Not such thing as a time machine
. As usual over here, we never give timeline, expected release day else, you'll just be deceived if we don't meet it. Better for us to surprise the community when it's ready.I've got a Question for pjanda1
Hey pjanda1
I have a Question about your reply to Dave…
You say, "it pains you to say it" referring about OS X and software for Audio editing software. Why do you think Software for OS X 10.5 & 10.6 are lacking in this area?
I'm pretty sure All Productuon software like ProTools and Logic are all made with Mac OS X in mind… and many others but those are both very powerful tools and are able to do a lot.
There is also other software out there that can do So much more like take out the specified instaments the user inputs and leave the vocals or change freq. or you name it. And even if the companies don't make it for OS X than all you have to do is Use BootCamp on your Mac or VM Fusion to run a virtual machine with OSX.
So really if someone has a Mac it would be Pointless to purchase a PC to run software built for a Win. base plateform.
Im 100% sure a Mac Can and Will run Every piece of Software Out today on a Mac. Infact I have Bootcamp and VM on mine. I run SolidWorks sometimes in VM when I don't want to reboot. It runs pretty smooth within the virtal machine. =)
Hey pjanda1
I have a Question about your reply to Dave…
You say, "it pains you to say it" referring about OS X and software for Audio editing software. Why do you think Software for OS X 10.5 & 10.6 are lacking in this area?
I'm pretty sure All Productuon software like ProTools and Logic are all made with Mac OS X in mind… and many others but those are both very powerful tools and are able to do a lot.
There is also other software out there that can do So much more like take out the specified instaments the user inputs and leave the vocals or change freq. or you name it. And even if the companies don't make it for OS X than all you have to do is Use BootCamp on your Mac or VM Fusion to run a virtual machine with OSX.
So really if someone has a Mac it would be Pointless to purchase a PC to run software built for a Win. base plateform.
Im 100% sure a Mac Can and Will run Every piece of Software Out today on a Mac. Infact I have Bootcamp and VM on mine. I run SolidWorks sometimes in VM when I don't want to reboot. It runs pretty smooth within the virtal machine. =)
hi,
I'm quite new here - have just got my miniDSP up running.
When using analogue input everything is fine - no noise.
When using digital input via miniDigi - there is some HF noise and some popping noises.
I have checked the 'Slave' jumpers on the digi and the dsp board - both are set to SLAVE as stated by documentation.
The source is Squeezebox, and it's digital output is working OK when feeding an external DAC.
Any suggestions to, what the problem can be ?
I'm quite new here - have just got my miniDSP up running.
When using analogue input everything is fine - no noise.
When using digital input via miniDigi - there is some HF noise and some popping noises.
I have checked the 'Slave' jumpers on the digi and the dsp board - both are set to SLAVE as stated by documentation.
The source is Squeezebox, and it's digital output is working OK when feeding an external DAC.
Any suggestions to, what the problem can be ?
Hello Hhenne,
These symptoms are typical of a wrongly configured I2S configuration in most cases... I may be wrong, but I say you have a look at the jumper chart for 2way speakers in our download section for a miniDIGI and miniDSP (p2). Each green square means a jumper needs to be in place.
If you want a confirmation, easier to email pictures of your board to our team at info@minidsp.com for us to review it. DIYAudio forum is just a side forum and our tech support team just doesn't look at it everyday...
Hope this helps
These symptoms are typical of a wrongly configured I2S configuration in most cases... I may be wrong, but I say you have a look at the jumper chart for 2way speakers in our download section for a miniDIGI and miniDSP (p2). Each green square means a jumper needs to be in place.
If you want a confirmation, easier to email pictures of your board to our team at info@minidsp.com for us to review it. DIYAudio forum is just a side forum and our tech support team just doesn't look at it everyday...
Hope this helps
Hello,
I apologize in advance, this is going to be a long post, much of it redundant. I just like to write everything down to make sure I'm not forgetting anything.
Simply skim to the bolded questions to save time reading, I tried to make them pretty much self-explanatory, even out of context.
So, I've been looking at the Behringer DCX2496 for quite some time now, but I never could justify buying one. It offers features I don't need in my home audio environment, and am therefor reluctant to spend money on. Thankfully, while hesitating to make my purchase, I became aware of miniDSP thanks to gainphile. I realized that for the money I was going to spend on big bulky pro audio equipment, I could get enough from miniDSP to complete both of the projects I'm working on.
However, I want to make sure that both of the projects I'm trying to do will work as I forsee them. Most of the parts are quite self-explanatory, and I have already confirmed myself using the datasheets, but some parts I'm still a bit unsure of.
Project I: Geddes style Multi-Subwoofer Setup
This is a project I've been working on for quite a while now, but only making slow progress.
The concept is described here on Markus Mehlau's website, but there is also a rather long discussion thread on the topic here in this forum.
The basic idea is to have 3 or 4 independently controlled subwoofers distributed around the room, to be able to control room modes, cancellation, and other unwanted bass effects.
What I need for this is a device that takes the single subwoofer output of my AV-receiver, splits it into 4 signals, and is able to perform the following equalisations on each of the 4 signals individually:
Using on of the several 4-way crossover plugins, most of these should be possible. However I have one question about the phase. I see that there is an option to reverse the phase at the output. 1. But is is also possible to rotate the phase by any other angle than 180deg? Or is adding delay equivalent to rotating the phase?
2. Would there be any reason for me to get the PEQ 4-Way plugin? Is there anything it can do, that the Advanced 4-Way plugin cannot? The flow-charts look identical.
Oh, in addition to all of the above, I need to perform a Linkwitz transform, as all of my subs are high-Q sealed woofers. But I've already read elsewhere that this is possible to create using custom biquad parameters.
I have created a flow-chart of how I am hoping to setup:
One of the major advantages here would be that I can easily incorporate the DSP unit into the enclosure of my custom built subwoofer amp, saving me from a) having an extra box in my already too full media rack, and b) from running 4 external XLR cables. I do plan to have a USB cable running from the PC to the miniDSP at all times, however I'd like the unit to be self-sufficient during the times my computer is off/broken, therefore I'm incorporating an additional power cable from the amps power supply. As this is however a 27V power supply (likely to be adjusted up to 30V), I decided for the sake of safety I'd like to put a 78XX series voltage regulator in the way, to stay in the safe input margins of the miniDSP. 3. Will this be a problem if there are two different voltages applied to the USB port and the DC power in?
Other than that most of the system seems pretty self-explanatory, and I feel should work pretty well. That leaves me with the question, which revision should I get? 4. Does anybody know what a typical voltage output of the subwoofer pre-out on an AV-receiver is? I've browsed through the users manual, and can't find any information on this. What's there to measuring this? Sine-wave generator + multimeter? Or is there a typical value for all AV-receivers?
Other than that, I think everything is clear.
Project II: USB connected 2-way Stereo System
Here's a new project I just started, and I'm hoping to finish this more quickly. This is a budget 2-way system for my second desk, to be run directly from my MacBook. Unfortunately the 3.5mm output jack of the MacBook is apparently not built to particularly high quality standards, so I'd prefer to output sound via USB. Therefore I'm going to need a MiniDSP and a miniStreamer.
Here's the deal, I'd like to set it up like this:
I'm hoping I can somehow run this device without any external power other than a single USB cable. 5. Is it in any way possible to piggyback the power going to the miniStreamer to also power the miniDSP - even when there's no USB cable attached to the miniDSP? In this case, I'd like the miniDSP to remain disconnected from the MacBook, excepting for the original setup, as I don't want to run 2 USB cables. I realize I could incorporate a small USB hub inside of my enclosure, but I'd prefer to just connect the respective 5V and GND points of the two boards.
Also, most (90+%) of the time I intend to connect directly via USB to the miniStreamer, however there is the possibility that I might have an iPod or the headphone jack of a laptop attached directly to the analog inputs of the MiniDSP. 6. In order to switch inputs between analog & I2s, is it necessary to jumper a connection, or can this be done via software? If it is necessary to jumper, I think I'll look into a way of controlling this via an external switch.
7. Once again, the question arises, which revision of MiniDSP to chose for use with iPod / headphone jack of laptop? I assume while using the miniStreamer, it's quite irrelevant which revision one has. Ideally I would hope I'd be able to expect the same input voltage as with Project I, that way I could get the 8 dollar discount on the two.
8. Global volume control is as simple as a 10k linear pot between pins 12, 24 and GND, right?
That's about all I can think of at the moment, I'm hoping I can use these boards for the tasks I intend, would be quite pleased if I could order the 3 boards at once to save shipping.
Many thanks in advance for your time.
I apologize in advance, this is going to be a long post, much of it redundant. I just like to write everything down to make sure I'm not forgetting anything.
Simply skim to the bolded questions to save time reading, I tried to make them pretty much self-explanatory, even out of context.
So, I've been looking at the Behringer DCX2496 for quite some time now, but I never could justify buying one. It offers features I don't need in my home audio environment, and am therefor reluctant to spend money on. Thankfully, while hesitating to make my purchase, I became aware of miniDSP thanks to gainphile. I realized that for the money I was going to spend on big bulky pro audio equipment, I could get enough from miniDSP to complete both of the projects I'm working on.
However, I want to make sure that both of the projects I'm trying to do will work as I forsee them. Most of the parts are quite self-explanatory, and I have already confirmed myself using the datasheets, but some parts I'm still a bit unsure of.
Project I: Geddes style Multi-Subwoofer Setup
This is a project I've been working on for quite a while now, but only making slow progress.
The concept is described here on Markus Mehlau's website, but there is also a rather long discussion thread on the topic here in this forum.
The basic idea is to have 3 or 4 independently controlled subwoofers distributed around the room, to be able to control room modes, cancellation, and other unwanted bass effects.
What I need for this is a device that takes the single subwoofer output of my AV-receiver, splits it into 4 signals, and is able to perform the following equalisations on each of the 4 signals individually:
- level (infinitely variable)
- low pass frequency (infinitely variable)
- phase (switchable or infinitely variable)
- parametric equalizer (optional)
Using on of the several 4-way crossover plugins, most of these should be possible. However I have one question about the phase. I see that there is an option to reverse the phase at the output. 1. But is is also possible to rotate the phase by any other angle than 180deg? Or is adding delay equivalent to rotating the phase?
2. Would there be any reason for me to get the PEQ 4-Way plugin? Is there anything it can do, that the Advanced 4-Way plugin cannot? The flow-charts look identical.
Oh, in addition to all of the above, I need to perform a Linkwitz transform, as all of my subs are high-Q sealed woofers. But I've already read elsewhere that this is possible to create using custom biquad parameters.
I have created a flow-chart of how I am hoping to setup:
An externally hosted image should be here but it was not working when we last tested it.
One of the major advantages here would be that I can easily incorporate the DSP unit into the enclosure of my custom built subwoofer amp, saving me from a) having an extra box in my already too full media rack, and b) from running 4 external XLR cables. I do plan to have a USB cable running from the PC to the miniDSP at all times, however I'd like the unit to be self-sufficient during the times my computer is off/broken, therefore I'm incorporating an additional power cable from the amps power supply. As this is however a 27V power supply (likely to be adjusted up to 30V), I decided for the sake of safety I'd like to put a 78XX series voltage regulator in the way, to stay in the safe input margins of the miniDSP. 3. Will this be a problem if there are two different voltages applied to the USB port and the DC power in?
Other than that most of the system seems pretty self-explanatory, and I feel should work pretty well. That leaves me with the question, which revision should I get? 4. Does anybody know what a typical voltage output of the subwoofer pre-out on an AV-receiver is? I've browsed through the users manual, and can't find any information on this. What's there to measuring this? Sine-wave generator + multimeter? Or is there a typical value for all AV-receivers?
Other than that, I think everything is clear.
Project II: USB connected 2-way Stereo System
Here's a new project I just started, and I'm hoping to finish this more quickly. This is a budget 2-way system for my second desk, to be run directly from my MacBook. Unfortunately the 3.5mm output jack of the MacBook is apparently not built to particularly high quality standards, so I'd prefer to output sound via USB. Therefore I'm going to need a MiniDSP and a miniStreamer.
Here's the deal, I'd like to set it up like this:
An externally hosted image should be here but it was not working when we last tested it.
I'm hoping I can somehow run this device without any external power other than a single USB cable. 5. Is it in any way possible to piggyback the power going to the miniStreamer to also power the miniDSP - even when there's no USB cable attached to the miniDSP? In this case, I'd like the miniDSP to remain disconnected from the MacBook, excepting for the original setup, as I don't want to run 2 USB cables. I realize I could incorporate a small USB hub inside of my enclosure, but I'd prefer to just connect the respective 5V and GND points of the two boards.
Also, most (90+%) of the time I intend to connect directly via USB to the miniStreamer, however there is the possibility that I might have an iPod or the headphone jack of a laptop attached directly to the analog inputs of the MiniDSP. 6. In order to switch inputs between analog & I2s, is it necessary to jumper a connection, or can this be done via software? If it is necessary to jumper, I think I'll look into a way of controlling this via an external switch.
7. Once again, the question arises, which revision of MiniDSP to chose for use with iPod / headphone jack of laptop? I assume while using the miniStreamer, it's quite irrelevant which revision one has. Ideally I would hope I'd be able to expect the same input voltage as with Project I, that way I could get the 8 dollar discount on the two.
8. Global volume control is as simple as a 10k linear pot between pins 12, 24 and GND, right?
That's about all I can think of at the moment, I'm hoping I can use these boards for the tasks I intend, would be quite pleased if I could order the 3 boards at once to save shipping.
Many thanks in advance for your time.
1. With an allpass filter the only parameters are the center frequency and the "steepness" of the phase shift.
2. To be able to use custom biquad parameters you need the advanced plugin. For calculating the biquad coefficients you can use this spreadsheet.
3. No, when usb is connected the external power is not used.
4. With a 50Hz tone you can measure this with a cheap multimeter.
5. I think so. Just use the external power in of the minidsp.
6. Can be done by software or a switch. The connections to be made are in the minidigi manual.
7. When using the I2S input of the minidsp the ADC is bypassed.
8. It's in the minidsp manual. Use pins 6, 12 and 22.
2. To be able to use custom biquad parameters you need the advanced plugin. For calculating the biquad coefficients you can use this spreadsheet.
3. No, when usb is connected the external power is not used.
4. With a 50Hz tone you can measure this with a cheap multimeter.
5. I think so. Just use the external power in of the minidsp.
6. Can be done by software or a switch. The connections to be made are in the minidigi manual.
7. When using the I2S input of the minidsp the ADC is bypassed.
8. It's in the minidsp manual. Use pins 6, 12 and 22.
Thanks for your answers.
1. Good enough for me I guess.
2. Excellent, great spreadsheet!
3. Good to know as well.
4. Well, although the smallest range my multimeter can do is 10VAC, I tested it on my laptop now, and it does seem to accurately display that my laptop puts out no more than 0.8V under normal circumstances. Will do my receiver once I get back to the media shelf tomorrow.
5. The problem here is not so much the power in of the MiniDSP, but rather the power out of the miniStreamer. There does seem to be a ground pin, but no power pin of any sort. I guess that means I'd have to solder a connection to one of the traces? Preferably directly at the USB port. This would probably void my warranty though, right?
6. Thanks. For some reason when I made my post I only saw a link to the datasheet, but not to the manual, now I see both. Either it was missing, or I was just temporarily blind (the latter being more likely)
7. So the revision only depends on the output voltage of my iPod (likely very low, so Rev A would be preferable)
8. Once again, must have been temporary blindness. Sounds easy as cheese.
Edit: No wonder I couldn't find it, the link is not on this page. And now I can't remember where to find the link anymore, thankfully it's still on my computer though.
I have now signed up and been browsing around miniDSP's own forums, and have read some stuff that slightly worries me, leading to one or two follow up questions:
9. If I connect the miniStreamer directly to the MiniDSP, is it correct that I have to input 48kHz (and maybe even 24bit, or is 16bit fine, and the MiniDSP will pad with zeros by itself?) audio to the miniStreamer, otherwise the MiniDSP can't handle the I2S? This would be great if this was a dvd only machine, unfortunately it's more of an audio only machine, so the sample rate will be 44.1kHz most of the time. 10. Is it possible for me to convert the sample rate within the computer (OS X), ie force it to output 48kHz at all times? Would this degrade the sound? The only other workaround would be to buy a MiniDigi as well - this is starting to get more expensive than I would have hoped.
5. Maybe it's a better idea to use an external power supply for the minidsp. With a jumper on the ministreamer you can put it in self powered mode so it gets its power from the minidsp. Maybe you have some 12 volt adapter lying around you can use.
9. The minidsp only accepts 48kHz. Being an I2S signal it can be both 24 and 16 bits. So without a minidigi you must set the properties of the usb-soundcard in your OS to 48kHz/24bit or 48kHz/16bit mode. In the picture you can see how it's done in Windows (sorry it's in dutch).
10. See answer 9.
9. The minidsp only accepts 48kHz. Being an I2S signal it can be both 24 and 16 bits. So without a minidigi you must set the properties of the usb-soundcard in your OS to 48kHz/24bit or 48kHz/16bit mode. In the picture you can see how it's done in Windows (sorry it's in dutch).
10. See answer 9.
Attachments
Well, I got out my Multimeter and did some measurements, and I also opened the signal info on my AV Receiver, and played around with my computer output settings, and was able to answer some more of my questions.
4. At 0dB volume, with a 50Hz sine wave, the subwoofer pre-out is giving exactly 2VAC according to my cheap multimeter, so it looks like Rev B is definitely the way to go for this system.
5. Seems rather tricky. I'd prefer not to use an external power supply (although I could probably scrounge one somewhere). I think my best bet would be to get a cheap 2-port passive USB hub and integrate it into the enclosure. That way I can supply audio to the miniStreamer, and control the MiniDSP, at the same time, while using only a single USB cable.
7. I also did some measurements here, and it would seem that while the output of the iPod always stays well below 0.9V, the analog output of my laptop tops out at exactly 0.9V - however VLC has a volume bar ranging to 400%, causing the voltage to go above 0.9V. I think to be on the safe side here, I'd better chose the RevB. By my understanding, that means I'm losing about 7dB in sensitivity, however given how rarely I plan to use the analog input here, I think I can live with that more than the risk of overloading. Also 8$ savings is nothing to complain about. Edit: it would seem, there is no bundle discount for Rev B, only for Rev A.
9. I figured out, I can definitely force the output of my computer to 48kHz, so that's a go. No need to put a MiniDigi in between, saving me a nice 70$.
So, my shopping list looks as following:
2x MiniDSP kit RevB 900-124b 198$
1x miniStreamer 200-030 55$
1x 4Way Advanced 900-072 10$
1x 2way Advanced 900-091 10$
Subtotal: 273$ + 35$ shipping = 308$ = 222.22€
Considering a DCX runs me at 270, and that would only be enough for one system, whereas I'm shopping for 2 systems here.... sounds like a nice deal for me. Just have to wait for my next paycheck and then I'm ordering. Unless I'm forgetting something?
4. At 0dB volume, with a 50Hz sine wave, the subwoofer pre-out is giving exactly 2VAC according to my cheap multimeter, so it looks like Rev B is definitely the way to go for this system.
5. Seems rather tricky. I'd prefer not to use an external power supply (although I could probably scrounge one somewhere). I think my best bet would be to get a cheap 2-port passive USB hub and integrate it into the enclosure. That way I can supply audio to the miniStreamer, and control the MiniDSP, at the same time, while using only a single USB cable.
7. I also did some measurements here, and it would seem that while the output of the iPod always stays well below 0.9V, the analog output of my laptop tops out at exactly 0.9V - however VLC has a volume bar ranging to 400%, causing the voltage to go above 0.9V. I think to be on the safe side here, I'd better chose the RevB. By my understanding, that means I'm losing about 7dB in sensitivity, however given how rarely I plan to use the analog input here, I think I can live with that more than the risk of overloading. Also 8$ savings is nothing to complain about. Edit: it would seem, there is no bundle discount for Rev B, only for Rev A.
9. I figured out, I can definitely force the output of my computer to 48kHz, so that's a go. No need to put a MiniDigi in between, saving me a nice 70$.
So, my shopping list looks as following:
2x MiniDSP kit RevB 900-124b 198$
1x miniStreamer 200-030 55$
1x 4Way Advanced 900-072 10$
1x 2way Advanced 900-091 10$
Subtotal: 273$ + 35$ shipping = 308$ = 222.22€
Considering a DCX runs me at 270, and that would only be enough for one system, whereas I'm shopping for 2 systems here.... sounds like a nice deal for me. Just have to wait for my next paycheck and then I'm ordering. Unless I'm forgetting something?
Yes, powering off USB. And the reason I need two add-ons is this is for two systems. 1 MiniDSP in System I, and 1 MiniDSP and 1 miniStreamer in System II. If you look up a few posts, you can see exactly what I'm trying to do.
EDIT: one more thing
11. is the SPDIF cable necessary for connection from miniStreamer to MiniDSP included? Or do I need to buy / solder it myself?
Last edited:
@ Jwmbro, I believe that knuisje did an excellent job (as usual) at answering most of your questions and I think that you should be set for your project.
In answer to your last question, see the miniStreamer user manual. No i2S cable is provided. It's a simple 2.54mm connector where you can solder or use a female mating header.
In answer to your last question, see the miniStreamer user manual. No i2S cable is provided. It's a simple 2.54mm connector where you can solder or use a female mating header.
I would like to request the addition of a "Copy" feature from channel 1 to Channel 2 in the 2-way crossover adv plug in.
I setup some a few EQing/XO settings on my first channel and it would be great to have those just copy over to my second channel without spending another 15 minutes to enter all the data again.
btw, great product. I took some small bookshelf speakers, added bass bins too them with the minidsp and I have a nice full range setup.
I setup some a few EQing/XO settings on my first channel and it would be great to have those just copy over to my second channel without spending another 15 minutes to enter all the data again.
btw, great product. I took some small bookshelf speakers, added bass bins too them with the minidsp and I have a nice full range setup.
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