Cubilux Budget 7.1 USB Sound Card Review

[amirm]

This is a review and detailed measurements of the Cubilux 7.1 USB Surround DAC and line/microphone input. It was kindly drop shipped to me and only costs USD $32.

From the pictures I assumed it was desktop sized but as you see, it is tiny. Fortunately it is made of metal and feels great in hand. You can see the connectivity better from company stock picture:

The other side has a USB-C connection used for both power and data.

Company doesn't state what DAC IC they use but likely is an ultra low cost USB interface usually used in motherboard.

Cubilux DAC Measurements
I was disappointed that even at max volume, we are short of nominal 2 volt output:

Performance is surprisingly good though. Distortion products are near -100 dB which is good enough to more or less resolve 16 bit data. Dynamic range is just as good:

I also measured the headphone out but sadly, it too had low output but now with more noise and distortion:

Frequency response and filter implementations are good:

As is Jitter for its class:

Couldn't run Multitone test since the signal is sampled at 192 kHz and I could only select 44 and 48 kHz (advertises 384 kHz). But did run IMD which showed somewhat serious problem:

Wideband distortion vs frequency is again good for the price:

Cubilux ADC Measurement
I selected the line in for testing here only to find out that it clips above 0.1 volt .

And as you see, only one input was working (Amazon reviews complain about similar problem on the output).

Noise is quite high. The much more serious problem is the frequency response:

I don't know what the heck is going on to produce that kind of response.

Conclusions
I expected a cheap plastic box but Cubilux delivers a premium metal enclosure, albeit in miniature. Best to use flexible wires or it will be yanked around easily.

The DAC response is surprisingly good in many areas. But there is a jump in distortion in IMD.

The ADC/line input is useless.

Overall my impression is more positive than negative considering that you are getting 8 channels of output. Still, why not save money on not eating lunch out a few days and getting a more premium solution?

I can't recommend the Cubilux surround DAC but I can see people going for it given the very nice value it brings.
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As always, questions, comments, recommendations, etc. are welcome.

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[whazzup]

@amirm Thanks for the review! Seen the product online multiple times and felt it's too cheap for what it's supposed to be able to do, and turns out it's true.
A question: can I safely say that generally for usb-powered multi channel dacs on the market, almost all if not all of them won't be able to output the full 2V per channel? Because that's going to require 16V at full 8-channel output? Unless it's spec-ed to use USB-C PD?

 

[amirm]

A question: can I safely say that generally for usb-powered multi channel dacs on the market, almost all if not all of them won't be able to output the full 2V per channel? Because that's going to require 16V at full 8-channel output? Unless it's spec-ed to use USB-C PD?

No. They could have a step up converter and output anything they want. Indeed we have dongles that produce 4 volts output.

 

[OldTimer]

Fine. It's $32.
Because MONEY TALKS

 

[whazzup]

No. They could have a step up converter and output anything they want. Indeed we have dongles that produce 4 volts output.

Oh interesting. Is there an example of a 5.1/7.1 usb-powered dongle that produces that output per channel?

 

[lowerfe]

This is much better than I expected. This is great performance for a $32 2 channel DAC, let alone a $32 8 channel DAC where the next cheapest option is 10x more expensive. For an 8 channel DAC this is an absurd value. This is a fantastic budget option for 8 channel DSPs for active speakers using a PC/laptop. This is much cleaner than the DAC on the MiniDSP 2x4, 2x4 HD, and the Dayton DSP 408.

 

[YouDontHaveEnoughBass]

I gave this top marks; 1v is plenty for my setup to get very loud and clean 7.1 output at this price is insane to me, I haven't seen any others anywhere near this price!

 

[Tell]

I gave this top marks; 1v is plenty for my setup to get very loud and clean 7.1 output at this price is insane to me, I haven't seen any others anywhere near this price!

Yeah this is great for the price, no complains!

 

[solawind]

This is much cleaner than the DAC on the MiniDSP 2x4, 2x4 HD, and the Dayton DSP 408.

Those are DSP devices, so it is not an apples-to-apples comparison here. DSP can be affected by internal resampling, for example, while DAC part is great.
Also, they may have a few dB worse SINAD, but it is likely not audible — but the IMD problem here can be audible on certain audio signals.

 

[lowerfe]

Those are DSP devices, so it is not an apples-to-apples comparison here. DSP can be affected by internal resampling, for example, while DAC part is great.
Also, they may have a few dB worse SINAD, but it is likely not audible — but the IMD problem here can be audible on certain audio signals.

I know it's not apples to apples, but the difference is not a few dB. The miniDSPs have a SINAD in the 60's, and they have an audible noise floor. This is ~30dB better. The miniDSPs have a bad DAC implementation that's purely due to bad engineering and not because of DSP functionalities.

If you've spent time working on DIY active speakers you'll understand the frustration of just how disappointingly bad the miniDSP 2x4 and 2x4 HD's are in terms of DAC performance, and how there are no DSPs with noise free DACs (which is an exceptionally low bar) except for the very expensive miniDSP Flex series and Hypex DSPs.

 

[whazzup]

Just a cautionary tale of 1V outputs:
At least for me, I didn't realized it could be a problem until I noticed my subwoofer output sounded very low. Eventually I traced it to the Xonar usb multi channel dac. The measured output was >15db less than from the integrated soundcard.

Yes, it's entirely possible your subwoofer has sufficient gain to overcome this deficiency. In my case, I had a Klipsch sub connected to the usb dac before the T5s and it seemed to work fine. So it's only on switching to the T5s that I noticed the discrepancy and investigated further.
So if you're trying to setup a 'cheap' audio chain, budget dacs and budget subs, this could throw a spanner in your works and you might end up blaming your sub if you didn't know better.

*Note: I have not used any usb-powered multi-channel dacs other than the U7, so I could also be totally wrong with this.

 

[solawind]

The miniDSPs have a SINAD in the 60's

Amir said the 2x4 HD's SINAD in the 90s range in his review. https://www.audiosciencereview.com/...d-minidsp-2x4-hd-dsp-and-dac.2674/post-146834
Those are the numbers I was referring to.

It is 18 dB worse than Topping D50 which puts it around 90.

 

[lordhumungous]

Cubilux products are unreliable .That has been my experience with their products.

 

[lowerfe]

I wonder if the line in frequency response looks like that because Amir measured the mic in rather than the line in. Such a high-passed response could make sense for a mic input to suppress pop sounds and reduced muffleness

 

[fordiebianco]

Sorry, I’m a bit thick when it comes to these things: I presume this will not have have the necessary codecs built in to listen to a 5.1 Dolby track from an SACD? How would you set that up using this nifty little unit?

 

[YouDontHaveEnoughBass]

You’ll connect it to a PC via USB and the media player on the PC will handle decoding

 

[NotInYourHead]

I believe the DAC chip used is the CM6206 from Taiwan's CM Media, which first appeared in 2000s. This DAC in particular seems to have come pretty close to spec sheet performance, better than older implementations that I've seen. Stated maximum DAC output is 1.1Vrms and that's indeed what we're getting.

I have a feeling the ADC problem can be driver related. Maybe Amir can install the drivers on CM Media's website and see if there's any difference?

 

[Robbo99999]

I gave this top marks; 1v is plenty for my setup to get very loud and clean 7.1 output at this price is insane to me, I haven't seen any others anywhere near this price!

I think that's a good way of looking at it, as long as the person knows it's Line In is basically broken, but if you don't need that then why not!

 

[Power Pop 23]

Thank you to the member who drop-shipped this ADC/Soundcard.

Thank you to Amir for measuring and confirming its capabilities.

With this knowledge, there may be fewer 1 Star reviews added to the listing at Amazon USA.

 

[Tell]

I know it's not apples to apples, but the difference is not a few dB. The miniDSPs have a SINAD in the 60's, and they have an audible noise floor. This is ~30dB better. The miniDSPs have a bad DAC implementation that's purely due to bad engineering and not because of DSP functionalities.

If you've spent time working on DIY active speakers you'll understand the frustration of just how disappointingly bad the miniDSP 2x4 and 2x4 HD's are in terms of DAC performance, and how there are no DSPs with noise free DACs (which is an exceptionally low bar) except for the very expensive miniDSP Flex series and Hypex DSPs.

The MiniDSP 2x4HD has a SINAD of around 97dB. I only hear hiss from mine awhen putting my ear a couple of decimeters from my tweeter (sensitivity at around 87dB). I don't remember my old 2x4 none-HD having any audible hiss either.