miniDSP kits, our answers to your technical questions - Page 12 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > miniDSP

miniDSP Low cost, modular Digital Signal Processor (DSP) kits for the DIYer from miniDSP.

Reply
 
Thread Tools Search this Thread
Old 16th April 2010, 12:49 PM   #111
diyAudio Member
 
trusound's Avatar
 
Join Date: Aug 2005
Location: Missouri
Send a message via AIM to trusound
Man... your Customer Service skills are top notch..

Sorry to beat this in the head but I want to make sure we are on the same field here..

on all channels available, I can have 31 bands per xover and 6 peq bands post xover per channel?.. Plus T/A and gain?

If that is the case, you and I are now best friends..lol

Quote:
Originally Posted by minidsp View Post
Hello Trusound,

Glad to hear that you find our products "sweet!"... lol
Unless i'm misunderstanding your questions, 31bands graphic Eq are indeed already there (check the plug-in section) for 2way and 4way crossovers.
As for the PEG, I'm guessing that you're thinking PEQ (as Parametric EQualizers with 3 parameters to be modified : frequency, gain, q).
These are also available under the plug-in 2way PEQ and 4wayPEQ.

Hope this makes sense,
  Reply With Quote
Old 16th April 2010, 01:30 PM   #112
durwood is offline durwood  United States
diyAudio Member
 
Join Date: Oct 2006
Quote:
Originally Posted by minidsp View Post
please clarify what exact scenario (maybe a schema) you're trying to have with multiple miniDSP? Then I'll try to see how that would be possible or not.
If I built a 5way speaker pair I would need 10 channels, add in subwoofer make that 11 or 12 for a stereo pair.

3 way LCR + sub
15-16 channels needed

Do you need more examples? I think that should suffice to explain a want or need for > 8 channels.

Quote:
A differential input for a balanced line would mean a split supply (+/-) which from a self powered USB device (+5V) isn't going to work that great. Stepping back to the miniDSP concept, miniDSP is the brain, the other cards are the I/O. It just happens to have un-balanced in&out. If there is a need for balanced input or wanting to use what we'd call "forward referencing" on the inputs, I'm afraid that it's going to be hard to make it happen on the miniDSP board itself.
You can treat unbalance like balanced. It's only potential difference. I'm not even sure you need a split supply, some opamps work off single supply no? Maybe I'm wrong, you have more experience than I do in designing electronics. If could be done it would be great, then signal ground and power ground would be isolated from each other and less complaints come back to you.

Building a differential amplifier : OPERATIONAL AMPLIFIERS
http://focus.ti.com.cn/cn/lit/an/sloa072/sloa072.pdf
http://www.eng.yale.edu/ee-labs/morse/compo/sloa058.pdf

Quote:
Yes that's correct. Only a single plug-in per miniDSP board.
Bummer. I guess we would have to suggest plugins to you in hopes you have the time and demand for them. Do you have a suggestions section on your website or here to keep them all in one spot?

Quote:
mmmh, curious where you might have read about this 10ms delay... We used to have it in our initial plug-in version but as we added features, we realized that we couldn't fit 10ms (which answer your question that in 4way, 7.5ms is the max). It's now 7.5ms (2.5m) and that's what is shown on all our datasheet. Thanks for letting us know if we made an omission somewhere on our website. These things happen.
My fault for not double checking the specs. I saw a screen shot of the software showing a range of 0-10ms.
http://www.minidsp.com/images/docume...%20plug-in.pdf

Last edited by durwood; 16th April 2010 at 01:54 PM.
  Reply With Quote
Old 16th April 2010, 10:17 PM   #113
diyAudio Member
 
trusound's Avatar
 
Join Date: Aug 2005
Location: Missouri
Send a message via AIM to trusound
another question that came to mind.. since this is mostly geared to DIYer's.. why not socket the DAC chips so that you can interchange and try out new ones?
  Reply With Quote
Old 17th April 2010, 12:06 PM   #114
diyAudio Member
 
Join Date: Nov 2006
Quote:
Originally Posted by trusound View Post
another question that came to mind.. since this is mostly geared to DIYer's.. why not socket the DAC chips so that you can interchange and try out new ones?

technically:

* these devices are SMD mounted

if you take in components on sockets, you will lose audio quality.
(already proven many years ago, with PSpice simulation and real life measurents)

* each type of DAC chip needs it's own surrounding parts, not easy interchangeable
same as above, not a sonic improvement, sine you will fiddle around with non-SMD


* maybe my best argument - the already achieved result!
I have listened to some multi thousand $ DACs and now we have a DIY gear which is able to beat them easily.
Not only in price, but in listening experience!


Music is naturally fluid, real life sounding, has deep, stable imaging. It's all there.
You can focus your thoughts on enjoying your music, no need to "improve" this and that...

I tried to put this into words, which cannot reflect the real experience.

my listening experience is supported by very good amps and horn speakers (they show you every detail of what is coming to them)

my statement is in no way an advertisement for miniDSP.
It has to be stated that it is at a "State-Of-Art" Level. Point.
  Reply With Quote
Old 18th April 2010, 03:30 AM   #115
minidsp is offline minidsp  Hong Kong
diyAudio Member
 
minidsp's Avatar
 
Join Date: Dec 2009
Quote:
Originally Posted by trusound View Post
on all channels available, I can have 31 bands per xover and 6 peq bands post xover per channel?.. Plus T/A and gain?
Trusound, have a quick look at the plug-ins audio flow diagrams on our website. You'll see that we unfortunately don't have 31 bands AND 6 PEQ on outputs. It's either configuration depending if you are taking 2way or 2way PEQ plug-in.
It's all about DSP requirements, 31bands are great visually, but utilize a lot of resources that may not be used. You can achieve a graphic EQ just as well with a PEQ I guess, just lock the q to a static value. Hope this makes sense.

Quote:
another question that came to mind.. since this is mostly geared to DIYer's.. why not socket the DAC chips so that you can interchange and try out new ones?
I'm not sure of your electronic knowledge, but if you were looking at a couple of datasheets, you'd realize that this idea isn't possible because each IC has a different pin-out, and most of them requires to be configured/initialized by a microcontroller to work. These 2 steps combined make it impossible to have a one for all socket. If you want to use your own ADC/DAC, that's why we have I2S on the expansion socket. Go at it and connect whatever IC you want, providing you follow the I2S requirements we explained in our tech note. Hope this makes sense.
__________________
www.minidsp.com - Low cost & modular audio DSP kits for DIYers - Follow our tweets @ minidsp
  Reply With Quote
Old 18th April 2010, 03:33 AM   #116
minidsp is offline minidsp  Hong Kong
diyAudio Member
 
minidsp's Avatar
 
Join Date: Dec 2009
To SPDriver,

Thanks for your very positive review and for participating to this thread with your user experience! :-)
We're certainly glad to hear that you're having a great experience with this little board and your miniDIGI setup.
__________________
www.minidsp.com - Low cost & modular audio DSP kits for DIYers - Follow our tweets @ minidsp
  Reply With Quote
Old 18th April 2010, 04:05 AM   #117
minidsp is offline minidsp  Hong Kong
diyAudio Member
 
minidsp's Avatar
 
Join Date: Dec 2009
Quote:
Originally Posted by durwood View Post
If I built a 5way speaker pair I would need 10 channels, add in subwoofer make that 11 or 12 for a stereo pair.
3 way LCR + sub
15-16 channels needed
Do you need more examples? I think that should suffice to explain a want or need for > 8 channels.
Starting with your 5way loudspeaker, you'll run into the limitation of needing 3 boards for that requirement:
- 2 x configured in 4 way plug-in
- 1xconfigured in stereo 2way. All together that would give you the 12ch you need.
Providing you link the I2S data line + clocks from 1 miniDSP (configured as I2S master) to the other 2 miniDSP (configured as I2S slaves by software configuration) you could indeed in theory do it.
The remaining examples with 13/15 channels will however become a bit more complex because you're once again limited with the number of channels out of a miniDSP (4ch) vs what you're trying to achieve for each speaker (5ch).


Quote:
You can treat unbalance like balanced. It's only potential difference. I'm not even sure you need a split supply, some opamps work off single supply no? Maybe I'm wrong, you have more experience than I do in designing electronics. If could be done it would be great, then signal ground and power ground would be isolated from each other and less complaints come back to you.
Building a differential amplifier : OPERATIONAL AMPLIFIERS
http://focus.ti.com.cn/cn/lit/an/sloa072/sloa072.pdf
http://www.eng.yale.edu/ee-labs/morse/compo/sloa058.pdf
Yes we're aware of that, what we call "forward referencing" is what you call "treat un-balanced like balanced". Just different terminology and we indeed know that you can use op amps off a single supply. (not our first day building a board.. ;-) We already did a bit of homework on this issue, and when you combine on one hand end users that a) want higher input capabilities b) end users that want a balanced input c)End users that want a self powered USB device (5V) and don't want to have a use a split rail supply (the only way this would work well) d) and us who try to limit the switching devices (power regulators) on this tiny board to make sure we don't compromise sound quality, it's simply impossible to make everybody happy. Once again, we're sidetracking from the concept. miniDSP board is NOT intended to be a one for all I/O card. If you want digital audio (which a lot of people don't want to pay for), then just purchase a Digital I/O card. If you want balanced input (which a lot of people don't want to pay for once again), then get a balanced input card. That's the way we see this working.
The day we release the balanced I/O cards, we will get the opportunity to please what I highlighted as a/b/c/d facts under one I/O card.


Quote:
Do you have a suggestions section on your website or here to keep them all in one spot?
You can always email us ideas, whether it will get implemented depends on whether it's technically feasible and whether our community members (current miniDSP owners) also see value into it. To be honest, while we're an open minded company staffing multiple forums and listening to the community, we also try our best to please our community members first, since they are the people who believed in us and make this story happen.


Quote:
My fault for not double checking the specs. I saw a screen shot of the software showing a range of 0-10ms.
http://www.minidsp.com/images/docume...%20plug-in.pdf
Thanks will update that pic. It's indeed confusing.
__________________
www.minidsp.com - Low cost & modular audio DSP kits for DIYers - Follow our tweets @ minidsp
  Reply With Quote
Old 18th April 2010, 12:32 PM   #118
diyAudio Member
 
Join Date: Jul 2006
Hi,

I want to replace my existing DCX2496 with miniDsp.

What are the DSP kit that I need to purchase?

Data source will be CD or USB.

Output 6 Channels (I2S), I want to use my own DACs (WM8741) which can accept I2S input.

How many miniDSP and miniDigi kits as well software Pulgin I need?

Gary
  Reply With Quote
Old 19th April 2010, 03:21 AM   #119
minidsp is offline minidsp  Hong Kong
diyAudio Member
 
minidsp's Avatar
 
Join Date: Dec 2009
Quote:
Originally Posted by shumgary View Post
Hi,

I want to replace my existing DCX2496 with miniDsp.

What are the DSP kit that I need to purchase?

Data source will be CD or USB.

Output 6 Channels (I2S), I want to use my own DACs (WM8741) which can accept I2S input.

How many miniDSP and miniDigi kits as well software Pulgin I need?

Gary
Gary,

Please make sure to realize that the USB port is for control only and not for streaming audio (In&Out of a PC). With this being said, for your setup to work, the required elements will depend if you want your miniDSP inside your speakers (along with your amps) or remote.

If in remote configuration, you will need:
- 2 x miniDSP kits, 1 configured as Master I2S, the other configured as Slave I2S
- 1 x miniDIGI for SPDIF/Toslink input
- 1 x 4 way plug-in
- And most important, for you to clearly understand how I2S works since you are planning a custom setup (with your own DACS) In other words, it means that we'd expect you to have understanding of electronics and how it works. There are so many DACs, configuration settings specific to the I2S signals (different clock rates) that it's impossible for us to support each custom project, so be warned that if you DIY electronic, you'll be on your own (with maybe support of other miniDSP community members). Having a look at the I2S tech notes on our website with this regards would be the first step I'd recommend to make sure you have an understanding that I2S isn't plug&play, like analog audio is.

Hope this information makes sense.
__________________
www.minidsp.com - Low cost & modular audio DSP kits for DIYers - Follow our tweets @ minidsp

Last edited by minidsp; 19th April 2010 at 03:23 AM.
  Reply With Quote
Old 19th April 2010, 12:35 PM   #120
diyAudio Member
 
Join Date: Jul 2006
Hi

For I2S output, what's the optimal configuration setting that miniDsp kit support?

Gary
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Utter novice looking for answers to easy questions: shnaggletooth Tubes / Valves 24 23rd August 2009 09:10 AM
simple questions, can't find the answers pjaneiro Multi-Way 14 8th August 2007 10:28 AM
#halojoy - Answers DIY audio questions In Person halojoy Everything Else 1 10th August 2003 01:52 PM


New To Site? Need Help?

All times are GMT. The time now is 07:36 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2