minidsp question

I have a few questions about using a minidsp instead of a passive crossover.



It looks like the minidsp 2x4 will replace both crossovers so is the only downside needing two amplifiers? will it sound as good as the passive crossover? Can the amps be different 120w a a/b amp for the woof and a class d amp or a 30w amp for the tweets? the minidsp kit costs about $200 I read the data sheet so what am I missing?
 
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Boy will you get different opinions on this one. Imo, the advantages of active xo (easy eq, room correction, steep filters, etc, far outweigh the ad-da conversion (assuming analog source). It is also an advantage that the amplifiers don't have to match. Tubes for the top, classs d for the bottom. But it is ni small feet re-engineering the crossover. Minidsp units are great for me.
 
thank you I have been trying to learn about crossovers and seems like one dsp unit will replace both crossovers. I do want to experiment with different configurations like tm tmm mtm and even fairly good passive crossovers are hard to get exactly right and even cheap components are expensive with shipping. it looks like you can even time align the drivers without the pitfalls a physically doing so. the fact that the amplifiers do not have to match is a great bonus. do you need the hd style or will the standard 2x4 suffice? can this level out small 2-db peaks and dips inherent in the driver?
 
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Ugg10

Member
2017-11-18 9:59 am
UK
Note that ideally the two amps should have the same anount or gain, otherwise one will get louder than the other as you increase the input voltage.

As @OllBoll says, ideally keep the signal digital until the last minute. The nanodigi is the one I went for so I can use my own dac. Feed it a digital signal (chrome cast audio is fine or cd or pc output), apply the digital filters (crossover, driver eq, room eq, sound profile, delay etc) and then convert to analogue using your favourite dacs (Khadas Tone Board?). This has 8 channel output so gives you the opportunity to do 2/3way and sub integration or 4way stereo.
 
On minidsp vs minidsp hd. I had an older minidsp so perhaps it has changed, but mine had very low output level on the outputs. The hd is much better in that regard. As for the other sonic differences, i thought the hd sounded better, but probably in my head. I have a lot of expensive parts, so not shortchanging the digital processing (24/96 i believe on the hd) seems to be worth the extra just in case.
 
thank you for the responses. It sounds exciting. is the minidsp2x4 unit good enough to match the sound of a passive crossover with good parts I have pretty good drivers and my current crossovers cost a considerable amount. I would like to just get the minidsp 2x4 kit for about 100 and try it.



I have the unik mic already I bought it last month to try to figure out the changes I made to some spreakers.



I am confused about keeping things in the digital realm as long as possible would this not go between the preamp and the two amps?


The three amps I have are way different from each other a marantz 1060 a primare a30.2 and a sure class d. so not sure how to figure out if they will have the same amount of gain.
 
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Johnsykes

Member
2018-03-25 10:18 am
if funds allow go for the minidsp 4x10 , i use amplifiers with different gains watts ,class d for sub woofers , a/b for woofers and mids , tube for tweeters , never had any problem matching them. if you use rca output you can choose 0.9vrms or 2vrms , other type of connections allow different gains check the online manual . i have a nanodigi too that way i can use my diydacs , just for the fun of building stuff. Next i will complete my first class A amplifier for my oppen baffle will be used with the minidsp 4x10
 
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I would be surprised if you preferred the sound of the passive crossover once you get the xo optimized digitally, good parts or not. Ideally you would eliminate the preamp. Digital source direct into the dsp digitally. Either USB or toslink. If you have an analog only source, thats the only time you'd use the analog in.
 

OllBoll

Member
2010-11-22 11:24 pm
I am confused about keeping things in the digital realm as long as possible would this not go between the preamp and the two amps?

For best performance the MiniDSP will become your DAC, where the filters will be applied in the digital domain before going to the DAC chips.

If you want fancy DACs then another option as descriped in some posts above is to use the NanoDigi to also do the filters digitally but instead of a good performing on-chip DAC you can use SPDIF to send to your own DACs. Requires multiple fancy DACs and the DACs on the 2x4 HD are pretty good unless you have crazy efficient speakers. And in that case you can probably get away with padding down the analogue output thus reducing the noise as you won't need the full voltage swing.
 
Thank you all for the responses it sounds like the minidsphd is the way to go. is it possible to run analog turntable with it and still loose the preamp. I guess there maybe phono preamps use the phono preamp analog jacks or keep the preamp and run analog sources thru them.


The only downside I see is that it will be more difficult to move the speakers around the house I did want to make smaller speakers so I could use in the living room or out on the porch in the summer. but with class d amps that may not be a deal breaker either. I just had a expensively sick dog and had to buy a new laptop and my amp is in the shop so it may be a little while before I can get the minidsphd but I am now convinced it is a better way for me to work on speakers. Everytime I order crossover parts the shipping alone is 30-50 dollars. To keep the quality of parts I am currently using I think the $300 for the minidsphd may be cheaper especially if (when) I make any mistake or miscalculations and have to reorder



thank you again for all of your help.
 
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Lojzek

Member
2012-02-10 12:12 pm
Croatia
One has got to find a way of dealing with costs introduced by purchasing passive parts. Getting a large number (hundreds of it) of small caps on discount and a bunch of magnet wire to build yourself any conceivable inductor is enough. Resistors are no problem. I remember buying a polyester 2.2 uF cap for 0.08€/piece and 1uF for 0.05€/piece. So if I needed a 22uF, I'd just take ten 2.2's in parallel.
 
I guess buying wire and making inductors would be one way to do it. the cost of the inductors like for 2.5mh with shipping is almost 100.00 one crossover would pay for the minidsp


so outside of having the use of usb and maybe playing louder does the hd have any other major advantages. The non-hd version is less than 1/2 the cost. I do not see using the usb for music I would think the analog preamp and the toslink from the macbook would cover my needs. or am I once again being short sighted?