audiophile sound from miniDSP

[soundnovice]

hi
i want to know if you can expect audiophile quality sound from using miniDSP used for activer crossovering for bi-amped speakers. is it better than using opamp based active crossover?

regard
pranam

 

[Shaun]

Not what you asked about, but search here for thread on comparison between MiniDSP and Behringer (and another) DSP crossover.

 

[lduarte1973]

the best sampling rate you can get with minidsp is 24bit/96 khz , i dont think there will be much difference for others with same sampling rate. if you have a cd player that upsamples to 192/384 or higher , you might want to have a look at electronic crossovers (analog) like marchand , but they are expensive.

electronic crossover, active crossover, discrete opamp, custom amplifier, passive preamp

 

[curryman]

A general answer is quite difficult
Using a digital crossover/EQ like the miniDSP you will definitely be much more flexible developing the crossover. Realizing the same number of filters and EQs using analog OP based circuitry can be quite complex.
Thus it also depends on your speakers and the amount of EQ they need.
Many community members (including me) tested the miniDSP with very good results, some published (measured and listened) comparisons to other digital crossovers (Behringer, DEQX).

 

[soundnovice]

my listening setup:
asus o!play air (will be used as source...i know its not audiophile grade player, but later will upgrade the setup to use its optical out) -> xover -> bi-amped speakers.
please tell me if this kind of setup allows for using miniDSP as a xover

 

[lduarte1973]

yes it does but besides the minisdsp you will also need a minidigi card if you´re using the digital out of your player

 

[Shaun]

What does the rest of you system comprise of (loudspeakers, for instance).

 

[soundnovice]

norge 2060 integrated amp(85w/ch at 4 ohms)
topping amp(25w/ch at 4 ohms)
diy 2-way speakers (visaton WS17e8 woofers-8 ohms and peerless india tweeters SR10DT-8ohms)

 

[soundnovice]

one more question. if i use miniDSP for xover, then can i use preamp? will there be any restrictions to select proper preamp which can match well with the miniDSP board?

 

[lduarte1973]

the rca analog in of the minidsp only accepts 2v (standart cd player output) , only the minidsp board 8x8 accepts more than 2v

RCA input: 2Vrms (8 dBu) in unbalanced mode
Phoenix terminal: 4Vrms (14 dBu) unbalanced OR 8Vrms (20dBu) balanced

i dont know if you can do this instead : use the preamp only before the woofer amp since the tweets dont need much power.

 

[soundnovice]

both the amps (for woofer and tweeter) i have are having volume control options. so may be i dont need any preamp i guess. if i ever need one to control the volume of overall system...then i need to connect preamp before miniDSP. in that case what are all the things i should take care to properly match preamp with miniDSP?

 

[soundnovice]

how do i know that my media player is having 2Vrms or 0.9Vrms outputs?

 

[curryman]

For best results (signal/noise ratio, distortions) you should keep an eye on a proper gain structure:

http://www.diyaudio.com/forums/diyaudio-com-articles/186018-what-gain-structure.html

As mentioned by lduarte1973 you should add a miniDIGI in order to go into miniDSP digital using SPDIF out of the O'play. This avoids additional (and unnecessary) DA/AD conversion. You won't need a preamplifier and you don't have to take care of 0,9V vs. 2V in this case
Volume control should be done after the DSP for best S/N and resolution. You can use the build in volume control option of the miniDSP (digital volume contol using a simple mono pot, take a look on the manual) or a 4ch control between miniDSP and amps e.g. using a suitable pot.

 

[soundnovice]

thanks to lduarte1973 and curryman. that solves my doubt. i am convinced that its safe and better to go for minidigi and minidsp combo.
now what should i need to consider while connecting miniDSP analog outputs to power amps?

 

[lduarte1973]

what is your doubt ?

 

[soundnovice]

i mean to match properly between miniDSP analog outputs and power amplifier inputs, what factors i need to consider? such as impedance or signal levels.
not sure if my doubt is baseless!

 

[curryman]

Output Impedance of the miniDSP is around 560Ohm, thus there should be no problem with usual input impedances of amplifiers.

However a short google search showed, that input sensitivity of both norge 2060 amp (500mV) and Topping amp (200mV) is quite low (miniDSP 0,9V). Here you could think about resistor networks to adjust sensitivities.

 

[lduarte1973]

on the minidsp is advisable to keep the lows and highs max level at -10db ( lower than original because of processing signal variation , mainly the tweeters ) , this is explained somewhere in the manual or in the plug ins manual

 

[soundnovice]

Output Impedance of the miniDSP is around 560Ohm, thus there should be no problem with usual input impedances of amplifiers.

However a short google search showed, that input sensitivity of both norge 2060 amp (500mV) and Topping amp (200mV) is quite low (miniDSP 0,9V). Here you could think about resistor networks to adjust sensitivities.

you mean bringing down the 0.9V output of miniDSP to 500mV and 200mV using voltage divider?

 

[curryman]

Yes, this might improve noise.
However you can try without resitors and just attenuate on the DSP first (output level for every channel can be configured in the software).