miniDSP introduction, what we do, who we are

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Hello DIYers,

Just a quick note to introduce ourselves to the diyaudio community. We're miniDSP, a startup company designing, manufacturing and supporting a line of low cost Digital Signal Processor modules targeted at the DIY audio market. Our team is made up of audio, electronic and IT geeks who are passionate about good audio, quality products and who got together with the idea of providing Digital Signal Processing at low cost. With miniDSP, we aim at building the first DIY DSP community, where community members have a say on what DSP product they'd like to have. When was the last time a DSP manufacturer asked you that question? :)

Digital Signal Processors are a great tool for audio processing application! However, most DSP Eval kit out there have a serious learning curve attached to them. So no matter how you look at it, you'll most likely spend more time coding than actually tuning your audio system! miniDSP kits don't require C programming knowledge, no need for you to build windows drivers or get your biquad equations out of the closet. We already did all that work for you and the end result is a module that get programmed in few minutes and can be upgraded for a different project with a new plug-in :)

I think that's about all for the intro... We'll post more threads for product releases and other community polls. In the mean time, feel free to bounce ideas, suggestions you'd like to see us implement. We'll all hears!

Check us out at www.minidsp.com

miniDSP Dev Team
 
Hello Dave,

As we speak, we've already hired a Mac programmer to move our code to Mac OS, so it's becoming more real by the minute. :)

Here are the current systems requirements
Mac OS X


  • Intel Core™ Duo 1.83GHz or faster processor; PowerPC® G4 1GHz or faster processor
  • Mac OS X 10.4.11,10.5.4, 10.5.5, and 10.6
  • 512MB of RAM
No estimate till release because as usual with engineering projects, timing could be modified. We also prefer releasing a feature late (but fully tested) rather than rushing for what will certainly be a buggy software. :)

I'll keep you updated when we're close to release.
 
frugal-phile™
Joined 2001
Paid Member
Hello Dave,

As we speak, we've already hired a Mac programmer to move our code to Mac OS, so it's becoming more real by the minute. :)

Here are the current systems requirements
Mac OS X


  • Intel Core™ Duo 1.83GHz or faster processor; PowerPC® G4 1GHz or faster processor
  • Mac OS X 10.4.11,10.5.4, 10.5.5, and 10.6
  • 512MB of RAM
No estimate till release because as usual with engineering projects, timing could be modified. We also prefer releasing a feature late (but fully tested) rather than rushing for what will certainly be a buggy software. :)

I'll keep you updated when we're close to release.

Absolutely wonderful news. Most manufactures just brush off the Mac and say run a Windows Virtual Machine.

Note that 10.5.x (Leopard) is now at 10.5.8 and finally pretty stable. Snow Leopard will be at 10.6.3 soon.

PowerPC support means that one can use any of the older Macs falling off the bottom to dedicate to the task (i have a 1 GHz G4 laptop & a 1.8 GHz G5 iMac currently sitting around doing little). When you get close, if you need any beta testers...

Bob (at CSS) had pointed you guys out before with the idea that some interesting product could be leveraged off of your modules.

dave
 
Dave,

Glad that you're appreciative of our effort trying to make it Mac compatible. :) As you may imagine, providing OS compatibility isn't always easy, but since we're Mac addicts as well, we couldn't see ourselves not releasing a Mac compatible version.. :)

Will let you know when things get closer to completion,

BR
 
I read your paper on I2S from your website. It seems I2S is limited to 48KHz and 64 fs. Would it support arbitrary input sample rate and fs with s/w change?

For example one may want to input 44.1KHz, 128fs at the input and 44.1KHz, 256 fs at the output. Most high-end DACs such as Wolfson 8741 requires 256fs with 44.1K material.


Hello Glt,

In an effort to keep miniDSP kit technical questions organized in one thread, I created a new thread here. http://www.diyaudio.com/forums/minidsp/158963-minidsp-kits-our-answers-your-technical-questions.html

Please check out my reply to your question & let me know if you have further comments

Thanks.
 
I recognize MiniDSP is a startup just getting off the ground, but in case it's a useful data point in determining the addressable market what I'd be looking for is

- 44.1kHz support
- SPDIF crossover input, preferably optical
- eight, preferably ten, crossover outputs --- optical SPDIF or ADAT preferred, balanced OK, not interested in unbalanced
- power amp modules that work with the crossover outputs
- four and five way crossover support
- linear phase LR4, B5, LR6, B7, LR8 crossover filters (time reversed IIR) or FIR equivalents thereof
- linear phase shelving filters for open baffle equalization
- linear phase equalization patches
- channel delays for time alignment
- a master volume control

My current setup with Frequency Allocator and a Saffire Pro 40 gives me most of this, aside from the power amps. So, while I really like the MiniDSP concept, I won't be buying one.

The other general piece of feedback I have is MiniDSP isn't detailed enough. For example, the MiniDSP datasheet mentions the boards are stackable but doesn't describe how they'd be put on the same word clock to get three way crossovers or beyond. The page for buying a kit doesn't list what parts come with it. The four way crossover doesn't indicate how the filters are implemented. So by the time I get done looking at the website I'm left with considerably more questions than answers. Particularly for things like THD and IMD on the analog outs, but for basic stuff like how the MiniDSP kit's output levels relate to the provided supply voltage too.

In particular, if the MiniDSP's dynamic range is 96dB the resolution is 16 bits. Not 24 as claimed. Manufacturers usually fudge such numbers so, in my opinion, being honest about them is a good way to differentiate your product.

I keep seeing mentions of the MiniAmp, but it's not on the website. Does it exist? I could be interested if it's something like an LME497x0 + LM3886 DC servo composite amp with balanced inputs, good bypassing, a solid power supply, and is expandable to five outputs.

Hope this helps. Good luck!

However, most DSP Eval kit out there have a serious learning curve attached to them.
Analog Devices' SigmaDSP boards are probably your closest competitor. Take a look at the crossover block in SigmaStudio; it's no harder to use than Frequency Allocator.
 
- 44.1kHz support
- SPDIF crossover input, preferably optical

That really is a big deal - I'd rather avoid unnecessary analogue stages, so I'd like to do all my source selection with digital signals - from my TV, CD player, Squeezebox etc. But I can't guarantee what formats they'll be in - the TV might give 44.1 KHz from broadcast signals, but pass through 48 KHz from the DVD player, the CD player will need 44.1, and the squeezebox will vary song by song depending on the source material.

So, the SRC you're planning will be vital. I have two questions:

1) Will it have a mux so we can feed it multiple sources?
2) How much will it cost? Some existing designs cost as much or more than the miniDSP board itself.

EDIT: Oh, and it'd be nice if we could switch from I2S mode to Analogue In mode in hardware - so, for instance, I could add an FM tuner to source selector.
 
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Hello,

Thanks for your feedback and while we'll never be able to fit everybody's needs & make everybody happy, we're always listening and trying to see how we can better our products. In the end, staying objective (on both sides, client&manufacturer) is what typically makes things happen.. So maybe giving the opportunity to answer to your question before shooting us in the leg would work better? ;)

First of all, indeed you're proposing here a long wish-list which is close to something you would ask for a product that has been out for more than 1 month. However, as we always said from day one, we're here to help the DIY community adding features on our product all the time so who knows how long before we can actually fit all your needs for under 100usd... :)

- 44.1kHz support
See question already answered in the technical thread already started here:

- SPDIF crossover input, preferably optical
Board is in rev 2 of prototyping so we hope to release it in 2 to 3 weeks. Your 44.1kHz request will work well here.

- eight, preferably ten, crossover outputs --- optical SPDIF or ADAT preferred, balanced OK, not interested in unbalanced
10 outputs is most likely too high on DSP power unless we kill some of the input processing (EQ). Curious on what would be the application?

- power amp modules that work with the crossover outputs
Yes, we indeed have a power amplifier that is coming out. Same thing, rev 2 prototype now being tested in few setup of our beta testers.

- four and five way crossover support
We have four way, not five, but who knows before we get 5.. :)

- linear phase LR4, B5, LR6, B7, LR8 crossover filters (time reversed IIR) or FIR equivalents thereof
We already started the architecture of an advanced plug-in that will allow you most of this.

- linear phase shelving filters for open baffle equalization
See above.

- channel delays for time alignment
See datasheet of crossover plug-in. We indeed already have time alignment available per output channel.

- a master volume control
Already implemented in all plug-ins. Just need to get a pot and you have a master output volume control.

The other general piece of feedback I have is MiniDSP isn't detailed enough.
Building a website where you get all the information you need is unfortunately not an overnight task.. :) Unlike an amplifier, these little boards (along with their plug-ins) indeed have a LOT of questions attached to them (like yours)... So yes, site could get more info and sorry to hear that you're not finding the info right away. My answer is that we're definitely working on it as you may see that we're updating the content routinely. For the measurements, we made our measurements at the local Audio Precision office, and need to get those in a proper format out there.

For example, the MiniDSP datasheet mentions the boards are stackable but doesn't describe how they'd be put on the same word clock to get three way crossovers or beyond.
Actually, you can't stack miniDSP kits together. You will be able to stack I/O boards (Amplifier/Digital I/O, High fidelity) but unfortunately not miniDSP kits. A limitation of the firmware to keep things simple and low cost.

In particular, if the MiniDSP's dynamic range is 96dB the resolution is 16 bits. Not 24 as claimed. Manufacturers usually fudge such numbers so, in my opinion, being honest about them is a good way to differentiate your product.
No processing is indeed 24bit and to be honest, measurements on the AP was around 98dB so we certainly feel that it's unfair to categorize us in that range of manufacturer. :( While working in some proper audio company, we've learned to derate our measurements like other good companies would... Not sure if we deserve to be blamed as our motto is certainly not to lie to the community but help it...
To get back to the technical aspect, the I2S is indeed 24bit, the processing is indeed 24bit with 28 to 56bit resolution for the filter (required for better resolution). The lower than usual dynamic range you are looking at has nothing to do with the bit resolution, but rather the limited input of the ADC. With our upcoming high fidelity balanced board, you'll get a lot more than you actually need.


I keep seeing mentions of the MiniAmp, but it's not on the website. Does it exist?
Yes, it certainly does (hope that by now you'll stop having the impression that we're lying on what we're saying?? :confused::confused: ).
As explained above, currently being tested by our beta testers. Stay tuned.

Anyway, hope this post is giving you a better idea on what we're doing. In general, we prefer words of encouragement to get things done and improve our products for the community, but your comments (although some we feel un-fair and we certainly don't agree) are well taken. :)

Please view our tech thread for all tech related questions. Thanks!
http://www.diyaudio.com/forums/minidsp/158963-minidsp-kits-our-answers-your-technical-questions.html


Best Regards
 
That really is a big deal - I'd rather avoid unnecessary analogue stages, so I'd like to do all my source selection with digital signals - from my TV, CD player, Squeezebox etc. But I can't guarantee what formats they'll be in - the TV might give 44.1 KHz from broadcast signals, but pass through 48 KHz from the DVD player, the CD player will need 44.1, and the squeezebox will vary song by song depending on the source material.

So, the SRC you're planning will be vital. I have two questions:

1) Will it have a mux so we can feed it multiple sources?
2) How much will it cost? Some existing designs cost as much or more than the miniDSP board itself.

EDIT: Oh, and it'd be nice if we could switch from I2S mode to Analogue In mode in hardware - so, for instance, I could add an FM tuner to source selector.

Dear TheSeekerr,

Very much a technical question that I'd rather answer in our technical thread to try keeping things organized.. :)

Thanks
 
Thanks for all the info; good stuff to know. I'll check back in a couple months to see where the v2 boards and amps landed. I suppose I should point out I apply similar scrutiny to most things audio, mainly so I can reason about the tradeoffs between purchasing or DIYing something in an informed way. Here's another example.

minidsp said:
10 outputs is most likely too high on DSP power unless we kill some of the input processing (EQ). Curious on what would be the application?
Five way stereo crossover. Specifically open baffle, so a fair amount of EQ would be involved. Basically what I'm saying is there's a higher end DIY market which in some ways might be more accessible than that addressable below USD 100. Those are the folks most likely to already be working with or evaluating Behringer DCXes and PC crossovers. And be looking for higher performance solutions, either in terms of avoiding ADCs and warped phase filters or the hassles of streaming through a PC.

A pricepoint above USD 100 doesn't concern me (though it's certainly a separate SKU from a sub $100 kit). I'll add up the BOM, look at the performance, and if the kit has attractive value compared to doing my own boards I'll buy it.

minidsp said:
hope that by now you'll stop having the impression that we're lying on what we're saying?? :confused::confused:
It's your company, your website, your diyAudio account, and your time. I do believe the folks who are going to be doing DIY digital crossovers are the kind of folks who appreciate marketing copy which saves them the hassle of reverse engineering derated specs to figure out what they'd actually be buying. But it's your call on whether that's a business opportunity you think exists or wish to pursue.
 
higher performance miniDSP

Hi Minidsp, I have read all your posts and FAQs and product PDFs and whole website...So I have a quite good idea on your point as a startup company, which is very interesting with your premade plugins and sigmaDSP chip (adau1701 based) board.
The idea to use a sigmaDSP is really EXCELLENT (perfectly suit the goal), but IMHO you missed the actual choice with the entrylevel adau1701 model....
Twest820 is right in that there is a bigger market for a more performance oriented DIGITAL crossover products (with more processing power and higher channel count and more digital oriented : included spdif receiver and more i2s outputs).
My point is : why did you seriously limit your project with the adau1701 (with its average included dacs and adc, and limited processing power and more important : i2s channel count output limit and no spdif receiver) ?
Do you really think that people are interested in the included average converters ?(using an ADC in the flow before the digital dsp is out of question for many of us...) and many are here for the best DACs possible.
Because of the adau1701 you have to design and sell another input board to address the minidsp lack of features. And customers have to get 2 minidsp boards to get a STEREO 4 channel crossover... BIG downside in my opinion

Do you intend to make another (higher end, digital only) minidsp board based on the ADAU1445 ? (featuring an included optical spdif input and headers for all the i2s I/Os)
THAT would be VERY interesting... imagine : cd player's or computer's optical (inherent galvanic isolation !) spdif stereo directly to adau1445 board (8, 10 or more channels crossover to I2s header (LJ or RJ pcm even) then to highend dacs (minidsp pro multidac boards or diy). That is exactly the goal of many diy enthousiasts....
Which IMHO you are trying to please but in a strange way...

KEEP up the motivation and work and minidsp future products could be very interesting to me and probably many of us.
Thanks, Eric
 
Eric,

Let me try to answer this post and your questions... But before doing so, I'd just like to mention that for us to have to spend time trying to justify the choices we made in our product dev is not entirely what we envisioned when we purchase this forum space. In other words, just a reminder for future threads that as a manufacturer, we try to be helpful, but having to write these posts: take time, energy... We see the purpose of this forum as a way to create a relationship between our DevTeam and DIYers, but please try to do a bit of homework before questioning too much our engineering/product dev. Maybe one day, if you have to manage multiple forums as we do, you will realize what I mean...

Let's start with the name of the product: a "mini"DSP. Not a DSP with 16 in, 16x out, rack mount based, a high speed DSP clock and a list of features outdoing most rack mount DSP for a fraction of the cost. When we kicked off this project, we asked ourselves: "How can we build a "small" board, "low cost"to manufacture, with a good set of features that could be flexible enough to fit a wide range of application?"

I don't know your technical background so won't be able to comment more, but to the naked eye, looking at spec sheets and just features isn't cutting it when it comes to product development. There are some simple engineering questions one would ask before starting any product dev project:
- Maybe we realized that one can't lay out a 100TQFP IC that clocks at 172Mhz on a simple 2 layer board? Going more layer, more engineering time to do a proper layout for high speed clock = more expensive to engineer/design = more expensive to manufacture = more expensive to sell. Already out of our specs.
- Maybe we also realized that while the 2 ICs you're trying the compare come from the same product line, they are very different in their sets of features, and what may look to you like a simple new features would have meant more firmware in the background&plug-ins to be able to handle the complexity. Once again, more engineering time = more expensive product.
- Finally, maybe we developed our product with a lot of other elements (which i don't have to list out), put them together and thought that providing some ADC/DAC with a DR of >98dB isn't as bad as most marketing department would make you think. Please let's not get into the dB argument and marketing race going on everywhere. My simple point is: "bigger doesn't mean be better". Do a bit of math, look at elements of your audio system (not talking just ICs, but the actual audio chain) that can pretend to these specs (speakers + amp being the worst), maybe you'll realize that marketting specs have a different agenda than getting better sound. But that's a different story, which I definitely don't want to start!! :) In the end, we did realize that 98dB could be better. We did realize that we would need a better analog I/O card and that this would not happen on the same small size I/O card than a Digital DSP cards. (not enough space, need more layers). Anyway, another long list of basic engineering concepts...

Who knows, maybe one day we'll indeed build a more complex product with more inputs, more outputs, more this more that... Right now, miniDSP is a low cost product, that is flexible enough to fit a wide range of applications and which we don't feel impose too many targeted features to the DIY community. The more features we add, the greater the complexity to engineer & manufacture it, the pricier it will become, and worst of it we will just out-market ourselves from what we initially envision: Helping the DIY community with a flexible solution.

Hope this make a bit of sense, thanks for your words of encouragements and who knows when we'll indeed consider one day building a different platform that fits the market you're after.

Best Regards,

Tony

PS: not sure if I'll have energy to go through another thread like this one. If you're trying to compare an apple with an orange, please do a bit of engineering research first. We do our best to educate, but there is a limit to how much time we're able to spend on these... Thanks!
 
Thanks for your time answering. I think at least this clears many points DIY people would have asked you anyway.
Thanks for you answers which perfectly address my points.

But just to tell you that I did not expect a big board featuring 16 outs analog balanced dual mono dacs... Or in fact yes THAT would be awesome...

I would just have been more interested in simply a digital only adau1445 board only with an included toslink spdif input and i2s headers... Maybe it is a bit more engineering, but after all not so hard coming from a company with engineers.

But you say "fraction of the cost" when you are in fact competing to devices that do the same if not more at the same price; yes not so DIY oriented.
Still I like your concept and ideas, but it is just that I am disappointed when I see how you handle the simple spdif to i2s, 4 channel stereo crossover application with 3 so simple boards instead of one simple...

Thanks again and rest assured I will not be asking questions with such long explanations needed, consider your reply as a reference post...
 
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Hi I have questions,

Is there available casing for mini dsp?

Does 4way xover require 1 mini dsp, Or 2 mini dsp and 2 4way xo plugin for stereo, costing $218- in total?

Can the 4 way xo setup be configured to become a 2 way bi-amp with xo point of say 80hz?

How does it compare in terms of sound quality over analog XO?

Is the sound quality of mini dsp suitable for high-end, audiophile, hyper critical , sound quality set-up use?

Thank you.
 
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