Sokel
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Good thing about noise is that if it's audible is there right away with some elevated level so you can see what to do next,doesn't need 87658276 tests to find out.
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Review and Measurements and miniDSP 2x4 HD DSP and DAC
- Thread starter amirm
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Point with the 2x4 HD is, it uses a basic AD/DA codec chip to connect to the outside analogue world. Firstly an AKM one and after the fire at AKM they switched to a BB chip. Both reasonable ones, not bad, not high end. Just standard, giving results reported in the review long ago. On the board is an extra I2S connector. But only for output, not for input. So if you ever want to "enhance" the thing, the most obvious way is to hook up better DA chips and use USB for input. I don't see any advantage to replace 50 cts electrolytic caps for €5 ones. Regarding noise, what I measured pure digitally with USB loop back and a simple 2nd order x-over, was a noise floor of -120dB. Although this is still an unresolved flaw, I don't think it is a real audible issue. Not for my set-up anyway.
Cool!
I wouldn't and i think that was the cause why this went sour for me, i suspect i had too many uncomfortable questions.
Anyway, maybe it was just the weather. Hopefully the measurements can tell us a good story.
As far as I understood the "problem" is only in ADC&DAC which would my case because I want to use them for my Auro-setup. I can only use the preout's of my AVR for that.
Although the AD/DA can be better, the noise problem I am talking about is in de DSP: https://www.audiosciencereview.com/...sp-measurements-and-rising-noise-floor.42383/
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Great, we'll all be looking forward to the results.
I know Sweetspot Audio. I bought a Panasonic BR-Player, an Oppo BR-Player and they made some working on some 12 channel DSPs for me. What I can say is that the soldering was good but it took sometimes very very long time, that I wanted to have my parts back. Some after 7months without soldering even 1 part in it and some not finished, that I had to learn soldering and doing it now for myself.
The biggest steps forward (for my ears) were things that I told them to do, what they have not done in the end and I did them myself. Descrete opamps with external power supply. It is difficult/tricky because you have to solder soic/dip8 adapters but the sound ....wow.
I sent some descrete opamps to "Sweetspot Audio" for testing and he said "this is another world" comparing to ICs and that he did not expect this.
"Loudspeakers" is not his "thing". I had to explain a lot to him.
Only my experiences.
The biggest steps forward (for my ears) were things that I told them to do, what they have not done in the end and I did them myself. Descrete opamps with external power supply. It is difficult/tricky because you have to solder soic/dip8 adapters but the sound ....wow.
I sent some descrete opamps to "Sweetspot Audio" for testing and he said "this is another world" comparing to ICs and that he did not expect this.
"Loudspeakers" is not his "thing". I had to explain a lot to him.
Only my experiences.
Even if the guy does magic on the little 2x4hd, it brings the price of the modified device to 443 euros (in Germany, audiophonics price for the minidsp, taking into account shipping both ways), not that far anymore from the 643 euros a minidsp flex from audiophonics as well costs, with all the supposed limitations of the 2x4 hd solved, proven and measured + quite some extra functionality onboard.
I personally would never go the mod way even if I believed it would actually do something relevant and noticeable. my 2 cents.
I personally would never go the mod way even if I believed it would actually do something relevant and noticeable. my 2 cents.
Cheers for sharing. When was this? Maybe the dude learned new stuff since then?
Well, 200€ saved is 200€. It's not nothing.
But i get you, at that cost the Flex starts to look fine.
D
Deleted member 48726
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Uhh! Are pre-orders available soon?They are probably waiting for the new tubes:
/cdn.vox-cdn.com/uploads/chorus_asset/file/13975058/408082main_fd10_full.1419968996.jpg)
NASA develops speedy vacuum tube prototype for computers in space
Researchers have developed a vacuum tube prototype that is both fast and tough against radiation, making it ideal for computers in space.www.theverge.com
D
Deleted member 48726
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Are the other minidsp products also using the same components than the minidsp 2x4hd? Think I compared them a while ago. Same sabre chip etc.?
Well. I'm a happy owner of the DDRC24 and can't hear any noise a ft from the speakers with 0 attenuation on my 32 dB gain amp.
Well. I'm a happy owner of the DDRC24 and can't hear any noise a ft from the speakers with 0 attenuation on my 32 dB gain amp.
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I received my 2x4HD yesterday evening and set it up this morning. One complication is my subs were hooked up to "left & right" and I changed to LFE which necessitated lowering the level to match the mains. The control panel software works, although it takes a while to get used to it. The unit runs a bit warm and does not have an on off switch. I measured 3.6 watts consumption idle. It's playing through a Crown 1502 (SINAD 78 dB), original LS50's and a pair of Rythmik L12 subs. Noise is not a problem even when added to the 1502 with its way below ASR's extraordinarily high standards SINAD. I can't hear anything a foot away from the mains with my ear on axis. That probably has a lot to do with the very low sensitivity of the LS50's.
There's a major improvement in the lower frequencies. I would have to say it's mostly due to being able to put a delay of 2.5 ms on the mains. Lower notes of piano music have a lot more definition. I did not do a blind A/B, but I attest it's a big difference. Maybe using a DSP for the low pass filter instead of the low level analog device built into the L12 subs helped, but I don't think it makes much of a difference.
Although the 92 dB SINAD is awful by contemporary separate DAC standards, it is in the ballpark for AVR's costing around $3k or the Behringer DEQ2496 tested here. The only other characteristic some would take issue with is the number of taps are limited. It's that way with most hardware EQ devices.
There's a major improvement in the lower frequencies. I would have to say it's mostly due to being able to put a delay of 2.5 ms on the mains. Lower notes of piano music have a lot more definition. I did not do a blind A/B, but I attest it's a big difference. Maybe using a DSP for the low pass filter instead of the low level analog device built into the L12 subs helped, but I don't think it makes much of a difference.
Although the 92 dB SINAD is awful by contemporary separate DAC standards, it is in the ballpark for AVR's costing around $3k or the Behringer DEQ2496 tested here. The only other characteristic some would take issue with is the number of taps are limited. It's that way with most hardware EQ devices.
TurtlePaul
Addicted to Fun and Learning
I just got a 2x4 HD this week. It sounds good: I hear no noise going into a Fosi v3 which feed Philharmonic Affordable Accuracy Monitors. So gain slightly on the low end for the amp and sensitivity on the low end for the speaker, but this is dead silent.
It is a tweaker’s paradise. I an using the 2x4 as a preamp primarily through the USB connection but can also use the Toslink and RCA for gaming consoles and such. It is crossing over my mains and sub in a 2.1 arrangement. It is correcting that the mains provably don’t have enough baffle step compensation in my room. It is correcting several low frequency room modes. It is delaying the mains to time align with the sub.
I feel like I have hours more tweaking to do: I aligned the delays by looking at the group delay but I can measure the phase speaker by speaker. I have taken out the bass modes from the sub but it is still causing ripples in the roll off of the high pass of the mains. I tried to use a broad filter to reduce highs to make the speakers warmer but it was too dark and I may try to add some mids. I was using the 2x4 to calibrate the sub volume but now the level is too low and doesn't trigger it out of standby all the time.
I will be tinkering for a couple of weeks. Will report back.
It is a tweaker’s paradise. I an using the 2x4 as a preamp primarily through the USB connection but can also use the Toslink and RCA for gaming consoles and such. It is crossing over my mains and sub in a 2.1 arrangement. It is correcting that the mains provably don’t have enough baffle step compensation in my room. It is correcting several low frequency room modes. It is delaying the mains to time align with the sub.
I feel like I have hours more tweaking to do: I aligned the delays by looking at the group delay but I can measure the phase speaker by speaker. I have taken out the bass modes from the sub but it is still causing ripples in the roll off of the high pass of the mains. I tried to use a broad filter to reduce highs to make the speakers warmer but it was too dark and I may try to add some mids. I was using the 2x4 to calibrate the sub volume but now the level is too low and doesn't trigger it out of standby all the time.
I will be tinkering for a couple of weeks. Will report back.
TurtlePaul
Addicted to Fun and Learning
I have also posted to the 'in room measurements' thread, but here is where I am after an hour this morning of tuning. 100 hz 24 db/oct LR crossover in a 2.1 setup. I am using the input PEQs to remove room modes, using the sub PEQs to pull down a couple of frequencies where there is ripple in its roll-off (I can't localize it with music even with a 100 hz crossover). Using the mains outputs PEQ to flatten a wide dip and several ripples 100 - 500 hz. Using time delay to adjust for the one cycle delay from the crossover, but I can still tweak that a little more because I couldn't figure out REW's phase alignment tool in the five minutes I had. The main input gain is both to provide headroom for filters and to volume limit in case a <2 year old or a 4 year old get a hold of the remote which controls main volume.
I sort of wish these guys would merge with Wiim.
Can't wait for the measurements.
As far as i know they have combined forces with Volumio for the MiniDSP SHD and SHD Power.
Yes, and I'm not a huge fan of Volumio. Wiim and Cambridge have streamers with multi-platform compatibility and stable software. That's where it's at. Otherwise it's not worth paying for anything more than ROPIEEXL on a pi*.
*arguably it isn't worth it for Cambridge, but at least they deliver a smooth software/hardware experience, compatible with all the different protocols.
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