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Old 17th August 2011, 08:36 PM   #341
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Originally Posted by Saturnus View Post
Many people also tend to forget that loudspeaker drivers themselves are very rarely linear phase themselves, so to get a true linear phase output you will have to use a non-phase linear crossover.
Here's the phase and Z response (1998 Stereophile review) for my passive xo ESL hybrid ML SL3. (Can you see the wiggles caused by the ~250Hz xo and ESL EQ?) If I used miniDSP to recreate (and improve!) the XO and the EQ for the ESL, I would like to flatten the overall phase response. Is this something that miniDSP can do now, or is it functionality that I can expect in the near future?
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Old 18th August 2011, 07:40 AM   #342
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In order to flatten the phase response (or to reach a constant group delay) you need to adress the phase independent from the amplitude. This is not possible using IIR Filters like the miniDSP does. FIR Filters could do this, however the DSP used on this platform does not have enough calculation power to perform FIR filtering. Disadvantage of linear phase speaker systems is a significant overall group delay (e.g. 70 - 100 ms in case of linear phase down to low frequencies). Doesn't matter when only listening to music, but for home theatre systems this might be a problem.
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Old 15th October 2011, 07:31 PM   #343
Cyan is offline Cyan  Italy
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I've just bought a true balanced dac and pre amp. I'm interested in the minidsp balanced version. Can you cofirm me that it accepts unbalanced in and out too? Since it has 4 outputs, can 2 of them be unbalanced and the remaining 2 balanced?
Do you also plan to make a in-box version with xlr connection AND a good psu?
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Old 21st October 2011, 11:25 AM   #344
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Originally Posted by Andersonix View Post
Here's the phase and Z response (1998 Stereophile review) for my passive xo ESL hybrid ML SL3. (Can you see the wiggles caused by the ~250Hz xo and ESL EQ?) If I used miniDSP to recreate (and improve!) the XO and the EQ for the ESL, I would like to flatten the overall phase response. Is this something that miniDSP can do now, or is it functionality that I can expect in the near future?
The phase you are looking at is the impedance phase. Replacing the passive crossover with an active one will remove impedance phase variation associated withthe passive crossoevr/equalization but it will not affect the impedance phase of the woofer or panel. This is not something that can be addressed with DSP. The low frequency impedance peak is that of the woofer resoance and at least one of the higher frequency peaks is that associated with the impedance peak resulting from the LC resoance of the ELS panel and its matching transformer. Also, if you remove the passive crossover make sure you measure the impedance of the panel. Most ELS panels have very low impedance at high frequency. This is the case with my Monolith panels, and if that is the case with your panels you should make sure you have a resistor of 1 or 2 ohms in series with the primary side of the matching transformer. Otherwise you may find you amp reacting badly to direct connection to the panel.
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Old 21st October 2011, 05:02 PM   #345
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Curryman and John K, thanks for the replies.

It would be neat if miniDSP could offer ways to flatten the phase response, or at least show the effect of XO and any EQ on phase, so one could avoid making things much worse....?
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Old 25th October 2011, 07:17 AM   #346
Jdot is offline Jdot  Australia
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Hi,

I have read this entire thread plus litrature on the miniDSP site and still have questions.

I would like to add subs to my system and cut off the low frequencys to my speakers. The miniDSP seems perfect for this.

This is what I would like to do:

Click the image to open in full size.

I want to let the DAC do the DAC and the miniDSP can do it for the subs. The DAC also has a remote volume control that I would like to use to control the volume for the whole system.

My question is how do I do this without having a second miniDSP after the DAC and going DA then AD and then DA again?

Also, will I need a miniDIGI before the miniDSP to handle the TOSLINK?


Cheers, James
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Old 25th October 2011, 10:04 AM   #347
DQ828 is offline DQ828  Australia
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Originally Posted by Jdot View Post
Hi,

I have read this entire thread plus litrature on the miniDSP site and still have questions.

I would like to add subs to my system and cut off the low frequencys to my speakers. The miniDSP seems perfect for this.

This is what I would like to do:

Click the image to open in full size.

I want to let the DAC do the DAC and the miniDSP can do it for the subs. The DAC also has a remote volume control that I would like to use to control the volume for the whole system.

My question is how do I do this without having a second miniDSP after the DAC and going DA then AD and then DA again?

Also, will I need a miniDIGI before the miniDSP to handle the TOSLINK?


Cheers, James
Yes you need a Digi before the MiniDSP to have digital input.

I don't think you will be able to have digital out to your DAC as the Digi will pass the whole signal to the MiniDSP to be broken up & you would need the remaining signal sent back to the Digi to get a digital output, as the MiniDSP doesn't have a digital output.

And I would have to say there is no chance your DAC can control the volume to the whole system.

If you leave the DAC out it's all possible.

Can anyone confirm that I'm right?
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Old 25th October 2011, 10:55 AM   #348
Jdot is offline Jdot  Australia
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Damn, looks like I'm going to have to rethink what I'm trying to build here. Thanks for your input 828.

I just want to split highs and lows in two different directions whilst using a good DAC with remote volume in as much of a stright line way as possible. The more I read the harder it seems to be able to do this?
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Old 25th October 2011, 11:53 AM   #349
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Without using the remote control volume option of your DAC it would indeed be possible with the miniDSP 2x4 and the miniDIGI.
Setup would be:
digital source -> miniDIGI (digital in) -> miniDSP -> High frequency out to miniDIGI -> DAC
Sub uses low frequency analog output of miniDSP.
It would be possible to use the volume control option of the miniDSP, however this is not remote :-(
Another option is to use the miniDSP 2x8. Though it might seem a bit over the top for this application, it features IR remote control of volumne and has better specs. Setup would be the same including miniDIGI.
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Old 25th October 2011, 11:57 AM   #350
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i believe you need mini dsp 8x8 to do that.

miniDSP 8x8 kit | miniDSP
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