What happens to Wiim sub when using USB out?

[davmol]

I recently moved my stereo from a bedroom to a living room and have added a new subwoofer, and so have finally started playing around with room correction. I happened to have the SMSL SU-1 in my hand while tidying and decided to plug it into the Wiim Ultra USB out, and then used an RCA splitter so I could switch between line-out and USB out to listen for any difference between the DACs. There was a difference but I think it's because the subwoofer is still connected to the Wiim, which might seem obvious to someone else but I've never had a sub in a stereo setup before,, so figured I would just ask here.

So if I were to compare another DAC to the Wiim, am I to assume that I'd need to do so with the subwoofer turned off (unless the DAC has a sub out as well)? I don't really intend to do any testing because I've been through it already with headphones and couldn't hear any difference, but I'm interested to know what to do when using a sub in the system.

 

[JeremyFife]

Hi,
If you want to compare DACs, look at the measurements.

If you want to compare whole systems (with different DACs) then take a deep breath and read up on blind-testing. TLDR: you need to match levels (electronically +/- 0.1 dB), switch between systems quickly and not be aware of which system is playing (i.e. blind). It's do-able, but there is some rigour involved;

Audio Blind Testing - You Are Doing It Wrong! (Video)

Just uploaded a video on the basics of performing controlled tests in audio. It was motivated by saving myself text in having to write all of this down when telling someone who to do these tests right. And as a counter to a few online personalities to keep saying they do "blind" tests yet when...

audiosciencereview.com

If you mean; how to compare systems when one has a sub and the other doesn't - I really don't think you can. Unplug the sub.

Personally, just enjoy the music

 

[davmol]

I have one system, it has a wiim ultra preamp, going to a Musical Fidelity A1 (clone), via an et30 vu meter/ switching box. I'm waiting on the arrival of a pair of fosi V3 monos. The amp outputs to a pair of Wharfedale Diamond 9.1, and I've just added a Wharfedale Diamond SW-150 sub.

I'm familiar with testing procedures and level matching from a previous round of comparing dacs using headphones, and I enjoyed the process, so I'll probably some more when I have time, such as class a / class d, or opamp switches.

So my question was simply to understand what is happening when I'm running an external dac using usb out (from the wiim), while also using the sub out from the wiim. Am I using two different dacs at that point, one for the mains and the wiim dac for the sub? In which case I can just switch off the sub whenever I get around to doing some a/b testing of devices.

 

[JeremyFife]

Ah, got you. Yes, you are using 2 different DACs if you include the sub connected to the WiiM.

 

[K2athome]

Does anyone knows if room correction will work over usb out? Im running an 1st generation wiim amp wich i want to run as a streamer only. I like the room correction software however.

Setup will be then : wiim amp -external dac-amplifier-speakers

Thanks

 

[davmol]

Yes PEQ and room correction will work fine with external USB DAC and amp.