Hey guys,
Been following diyaudio threads for a while on how to build crossovers for a custom set of active loudspeakers but not knowing all the parameters of my enclosure/drivers i'll choose, I hardly see how passive crossover would be efficient option...A digital crossover rack mounted unit is also a bit out of my budget...:-(
Doing a google search, I found this neat small DSP module that could be used as a digital crossover. www.minidsp.com
From what i understand, It's a small DSP with a PIC that is configurable via their software. It's a startup from Hong Kong from what i can see, anybody heard of them? At 125USD/module, it sounds like a great fit for my student budget!
I'm planning to get a board this week and will let you know how it goes. Will follow up with some pics and review of how it sounds.
In the mean time if any of you has any other suggestions, let me know!
Been following diyaudio threads for a while on how to build crossovers for a custom set of active loudspeakers but not knowing all the parameters of my enclosure/drivers i'll choose, I hardly see how passive crossover would be efficient option...A digital crossover rack mounted unit is also a bit out of my budget...:-(
Doing a google search, I found this neat small DSP module that could be used as a digital crossover. www.minidsp.com
From what i understand, It's a small DSP with a PIC that is configurable via their software. It's a startup from Hong Kong from what i can see, anybody heard of them? At 125USD/module, it sounds like a great fit for my student budget!
I'm planning to get a board this week and will let you know how it goes. Will follow up with some pics and review of how it sounds.
In the mean time if any of you has any other suggestions, let me know!
Alright, will order the board today and let you all know how it goes! I wanted to make a 3 way box, but for now on, a bi-amped box will be a good start! With one module, I can do my left and right, so i just need a small stereo amp module and i'll be good.
But yeah, I agree with you about the website. Needs a bit more details on how to configure the module... The link I found useful is the manual that I got from here. It seems dead nut simple to load/reload configurations or modify the algorithm settings.
I'll try to send an email to their support to see if the IDE is an option... For now on, I can't see myself writing DSP algorithms though... As long as their plug-in configuration works and they update them with new ones, I'll be happy!
With one module, I can do my left and right, so i just need a small stereo amp module and i'll be good. But yeah, I agree with you about the website. Needs a bit more details on how to configure the module... The link I found useful is the manual that I got from here. It seems dead nut simple to load/reload configurations or modify the algorithm settings.
I'll try to send an email to their support to see if the IDE is an option... For now on, I can't see myself writing DSP algorithms though... As long as their plug-in configuration works and they update them with new ones, I'll be happy!
Before his sad passing, Bob Stout mentioned he was working with some sort of low cost usb programmable dsp chip.
I think a really interesting area for DIY would be wavefront reconstruction and similar dsp heavy approaches. It's something the home audio industry will take quite some time to adopt, since product lines are format driven (ie 5.1).
I'd love a board that combined:
- reasonable FIR capability
- DAC
- an IC based amp of modest power
- ethernet connectivity with PoE
Combine such a thing with reasonable cost full range drivers and a few woofers, and one play around with all sorts of wavefront forming approaches at fairly reasonable cost.
I think a really interesting area for DIY would be wavefront reconstruction and similar dsp heavy approaches. It's something the home audio industry will take quite some time to adopt, since product lines are format driven (ie 5.1).
I'd love a board that combined:
- reasonable FIR capability
- DAC
- an IC based amp of modest power
- ethernet connectivity with PoE
Combine such a thing with reasonable cost full range drivers and a few woofers, and one play around with all sorts of wavefront forming approaches at fairly reasonable cost.
Alright! Ordered the board and got a reply from them that i should receive by mid week. Gotta get my cabinet and speaker ready now! Darn...
Wigginjs, I did ask in a separate email to them if they were planning to issue an IDE for the board, and already got a reply.. (man, they're fast!
From what the dude said in his email, IDE is not going to happen anytime soon. Too much work to support the product and problem with making their tools available to everybody (not open source I guess?). On the other hand, he did say that if I had some specific ideas, they would put them together and add them together for future configurations.. Fire them an email with your comments/ideas, you'll see that they've been really responsive with my questions...
Jason, i like the idea of PoE + DSP, neat idea but isn't PoE is only 15W? Or I guess that you could power it with a PoE injector of whatever you need?
Their website talks of future boards so I did ask them what's the deal with that... Apparently, it'll come out end of December/early next year and is basically Digital In/Out and Digital Amp.... maybe what you're looking for...
Anyway, more to follow when I receive the actual board!
Wigginjs, I did ask in a separate email to them if they were planning to issue an IDE for the board, and already got a reply.. (man, they're fast!
From what the dude said in his email, IDE is not going to happen anytime soon. Too much work to support the product and problem with making their tools available to everybody (not open source I guess?). On the other hand, he did say that if I had some specific ideas, they would put them together and add them together for future configurations.. Fire them an email with your comments/ideas, you'll see that they've been really responsive with my questions...
Jason, i like the idea of PoE + DSP, neat idea but isn't PoE is only 15W? Or I guess that you could power it with a PoE injector of whatever you need?
Their website talks of future boards so I did ask them what's the deal with that... Apparently, it'll come out end of December/early next year and is basically Digital In/Out and Digital Amp.... maybe what you're looking for...
Anyway, more to follow when I receive the actual board!
These look interesting.
I want to create a three way active crossover but with these it looks a little problematic..
If I could take a mono input to two of the units and output four bands (tre,mid,wof,sub) from each I'd at least have a configurable crossover. Might need a y adaptor across the two input rca's (would that work?)
The problem comes when controlling them. Presumably I'd need to run the software twice, once for each device.
Then comes using them with a digital input. Would it be possible to have a single digital in, controllable with a single potentiometer for analogue output level, again with the same crossover outputs.
My knowledge of electronics is very limited!
Like you I intend on building my own three way speakers and find the idea of building passive crossovers much less appealing than buying some power amps and passive crossovers.
Regards,
Jai
I want to create a three way active crossover but with these it looks a little problematic..
If I could take a mono input to two of the units and output four bands (tre,mid,wof,sub) from each I'd at least have a configurable crossover. Might need a y adaptor across the two input rca's (would that work?)
The problem comes when controlling them. Presumably I'd need to run the software twice, once for each device.
Then comes using them with a digital input. Would it be possible to have a single digital in, controllable with a single potentiometer for analogue output level, again with the same crossover outputs.
My knowledge of electronics is very limited!
Like you I intend on building my own three way speakers and find the idea of building passive crossovers much less appealing than buying some power amps and passive crossovers.
Regards,
Jai
Yeah, it's only like 12W usable also. But for wavefront synthesis approaches the whole goal is to have the sources summing coherently, so I don't think per source gain is as important. Though comb filtering will cause a loss at high frequencies depending on the spacing that you may need some power to overcome.
Stuff like this makes me wish I hadn't dropped out of uni! That's exactly what I was learning to do at uni, including DSP programming and the maths involved, etc... Oh well.
It would be nice to see affordable commercial DSP crossover units (or do they already exist?) Affordable is quite a variable though, I appreciate.
[Edit] - fellow Arsian? :d
digital in and out would be great for this board, either i2s or spdif...
I'm sure there's enough info online if you want to go give DSP programming a go, I've done some assemley programming in the past, and it's not for the faint hearted...
What course did you do? I did Audio Tech, and while it covered many things, DSP programming was glossed over, even tho we covered basic FFT type stuff.
I'm sure there's enough info online if you want to go give DSP programming a go, I've done some assemley programming in the past, and it's not for the faint hearted...
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seems a little pricey given Beagle Board @ ~US$150
or even cheaper Atom based SBC - which have all the DSP horsepower anyone could want for audio crossovers for ~ 1/2 that price
hardware cost is usually irrelevant - programming effort is going to eat up your time without a good dev environment and dirvers/interfaces for exactly what you want - how many 100's of hours is your time worth before you'd have won by working for minimum wage to buy another desktop PC?
or even cheaper Atom based SBC - which have all the DSP horsepower anyone could want for audio crossovers for ~ 1/2 that price
hardware cost is usually irrelevant - programming effort is going to eat up your time without a good dev environment and dirvers/interfaces for exactly what you want - how many 100's of hours is your time worth before you'd have won by working for minimum wage to buy another desktop PC?
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yes, but how do you split the output signal, and how do you correctily take analogue in? at what price?
what puzzles me is that if it does ADC/DAC on board, then why don't give a digital usb input too? and how good will the output section be?
anyway the fact that they are tring to bring up a diy DSP community, they have
a forum started, is really interesting, and one can ask their engeeners to develop specific cases and ideas...
i sent an e-mail to them, got very quick support, but i think i must wait to buy and try until i end my current build.
me asking for shipping price (i asked cause it's always a big problem to italy):
Shipping to Italy is 35USD and if you combine multiple boards to the same shipment, I won't add cost and can ship them together to you.
me asking if suitable for OB crossing, silly question, but i'm a newbie:
I think that the digital crossover plug-in (attached datasheet) + miniDSP kits will make a perfect fit for your project. The board is so small that you can add them inside your amplifier, powered internally from a clean external DC supply. (4.5 to 24VDC), or just put them in one of your enclosures. We'll add some enclosures for the board to our shop pretty soon.
me asking what are the other products already mentioned on their site:
MiniAMP is a 2x20W or 4x10W digital I2S amplifier module while MiniDigital will be an SPDIF/Toslink board. they will both stack up on top of MiniDSP. As for your question about MiniWatt, no we're not behind this project.
me asking about how much gain can be obtained in the lower region:
The graphic equalizer is a 31 bands, so yes you'll be able to equalize all the way to 20Hz. The range goes between +/-12dB per frequency but obviously when you boost 2 frequencies next to each others, you get more gain.
then there was an example with a resulting +15db at 25hz.
to me this product make sense, probabily more than a beringher ultracurve or so.
me asking for shipping price (i asked cause it's always a big problem to italy):
Shipping to Italy is 35USD and if you combine multiple boards to the same shipment, I won't add cost and can ship them together to you.
me asking if suitable for OB crossing, silly question, but i'm a newbie:
I think that the digital crossover plug-in (attached datasheet) + miniDSP kits will make a perfect fit for your project. The board is so small that you can add them inside your amplifier, powered internally from a clean external DC supply. (4.5 to 24VDC), or just put them in one of your enclosures. We'll add some enclosures for the board to our shop pretty soon.
me asking what are the other products already mentioned on their site:
MiniAMP is a 2x20W or 4x10W digital I2S amplifier module while MiniDigital will be an SPDIF/Toslink board. they will both stack up on top of MiniDSP. As for your question about MiniWatt, no we're not behind this project.
me asking about how much gain can be obtained in the lower region:
The graphic equalizer is a 31 bands, so yes you'll be able to equalize all the way to 20Hz. The range goes between +/-12dB per frequency but obviously when you boost 2 frequencies next to each others, you get more gain.
then there was an example with a resulting +15db at 25hz.
to me this product make sense, probabily more than a beringher ultracurve or so.
Mike, it was Electronic Systems Engineering at Manchester Uni. A general EE degree, but with a systems engineering slant. I was more into the digital side of stuff... but the course was very light on practical analogue and circuit design etc DSP was a third-year course - I have the course notes actually, but it was based heavily on the 2nd year Signals & Systems material (lots of hard math )
)True, but I'd sincerely hope that no DSP chip ever went to market without an IDE and standard library...
Don't want to rain on your parade, but it seems the Behringer digital crossover is about the same price (£150 in the UK). Which actually makes it a bargain IMO.
Still, it would be a neat DIY project and if they did fit inside another component case that's one less box in your rack - always a worthy goal. Most pro/studio type gear is a bit ugly IMO too... (if you don't like the hitech look, anyway).
Actually, if you got some of those small ICE power modules you could make a neato combination crossover/amplifier unit
Well, it seems like this little board is steering up all sorts of points of views & ideas, that's neat! The kit will be arriving tomorrow according to the tracking # they gave me so I'll try to get the rest of my project ready over the week end...
Doomlord, I knew about the Behringer units but that's not exactly what I was looking for. I really want to build a set of digitally processed bookshelf speakers with embedded amplifiers (active studio monitors style). I didn't want to use a full blown equipment rack of gear next to my bed!
I just want to build the speaker, tune them well with their software+measurement and be done with it. Then, I will run the DC power from a clean PSU inside my active speaker. (Guess it will be the same as the amp since it takes up to +42VDC)
Anyway, that's the plan so far... I didn't know about the digital i/o board but I guess that when they release it, that will be neat addition to input Toslink.... but for now on, i've already got my hands full!
The kit will be arriving tomorrow according to the tracking # they gave me so I'll try to get the rest of my project ready over the week end... Doomlord, I knew about the Behringer units but that's not exactly what I was looking for. I really want to build a set of digitally processed bookshelf speakers with embedded amplifiers (active studio monitors style). I didn't want to use a full blown equipment rack of gear next to my bed!
I just want to build the speaker, tune them well with their software+measurement and be done with it. Then, I will run the DC power from a clean PSU inside my active speaker. (Guess it will be the same as the amp since it takes up to +42VDC)
Anyway, that's the plan so far... I didn't know about the digital i/o board but I guess that when they release it, that will be neat addition to input Toslink.... but for now on, i've already got my hands full!
I'm NOT being a cheerleader or promoter here. believe me. But the TechTalk forum at Parts-Express has been the definitive point of contact and lurking source for XO design etc for years. The stogy old regulars will hassle you to death if you ask them to design a XO or anything for you, but will point you to all the tons on info on anything to do with XO and speaker construction. The years worth of info and posts can answer most of your questions.
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