Looking for a balanced A/B switcher

[manmower]

Okay so I'm feeling a bit dumb right now.

I've got a pair of monitors that can take balanced audio via TRS or XLR.

I would like to connect two interfaces to them and A/B between the two (there is no real need to mix). One interface does balanced out via a pair of TRS outputs exclusively, the other only does balanced over two XLR outs.

What I've been trying to search for is either a switch that could take both the 2xTRS and 2xXLR inputs directly, or two pairs of the same type (I'm assuming I can always use adapter cables for one of the interfaces). And then it should have a pair of TRS or XLR outputs to connect my monitors.

I feel like a simple passive switch for this should exist and not cost a fortune? But I am having a surprisingly hard time finding it. All I can find seems like overkill: more features than I need and € 100+.

Not sure what's going on here. Maybe I'm on the wrong track and there is an an even simpler solution, maybe I'm just not using the right terminology to search for what I need, or maybe my expectations about finding this for cheap are way off.

But before I waste my money I thought I'd ask here anyway.

Pls halp.

[thawkins]

It looks like you want to have two interfaces hooked up to your computer simultaneously (or two separate computers) and you want to A/B test them.

It also looks like your monitors have matching inputs so that you can connect interface A using TRS, and connect interface B using XLR.

So I may be dumb, it seems like you can just create an aggregate audio device (natively possible in macOS, ASIO4ALL in Windows, Linux has JACK), and then set up a DAW project so that you have the same test track that is sent to both interfaces, and you toggle between muting the out that goes to interface A and B.

 

The only snag might be that your monitors somehow do not let you to send audio from both inputs at the same time, or that there is some gain setting that does not match (i.e. TRS always sounds more quiet than XLR or vice versa).

 

I think that the logical headache is that usually A/B switches are meant to switch one input around different outputs, but what you want is switching different inputs for the same output.

[manmower]

In retrospect I don't know why I was being all mysterious about what I'm trying to accomplish in my original post. All I'm trying to do is play my Helix LT (XLR out) through the same Kali LP-8 monitors I use with my computer (M-Audio M-Track 2X2M, TRS out).

I referred to the Helix as an interface because technically it is but that's not really how I want to use it, I just want to have stereo from it straight to monitors, completely separate from the computer. Without having to mess with the cables every time. I could use the Helix as my computer's audio interface but it seems nuts to have the Helix running all day as a glorified sound card? Plus I like being able to move it around and play through headphones in other rooms.

Having TRS cables from the M-Track and XLR from the Helix connected to the monitors at the same time is a no-no according to the manual although I can't tell you the reason why.

I think I'm roughly on the right track now looking for some sort of "switcher" / "monitor controller" (used in reverse if need be), just trying to find something minimal and cheap that'll do what I want.

[thawkins]

I feel in your situation I would just use a simple mixer (passive if possible - just to reduce cable clutter). Something like in this list https://www.bhphotovideo.com/c/buy/Analog-Utility-Mixers/ci/8182/N/3992462105

[TubularCorporation]

If it's passive it's bidirectional, although with XLR you might need adapters if you use something designed as a passive output selector as a input selector.

 

There are tons of audio switchers aimed at the video market, new and old.  If you could deal with unbalanced the Kramer video switcher I use has an audio variant that can rout up to 8 inputs to any combinatipn of outputs (splitting only - one input can go to multiple outputs but not vice versa) using relays, with user presets for different routing.  I paid $35 for my composite video model but the audio versions cost because they're not obsolete:

https://www.ebay.com/sch/i.html?_nkw=kramer vs88a

 

They make a passive balanced switcher that's exactly what you want but it's pretty expensive, and not much cheaper used:

https://www.markertek.com/product/vs-4x/kramer-vs-4x-4x1-balanced-audio-passive-switcher

 

You could probably find something cheaper on aliexpress or something. These are probably OK but you'd need one for each speaker:

 

https://www.ebay.com/itm/Mini-2-way-Stereo-Passive-Balanced-XLR-Audio-Switcher-Box-Mixer-Sound-Splitter-/254262601784

If you don't mind the size, you can usually find balanced audio+video matrix switcher for less than an audio-only one, sometimes a lot less, but they're usually 2u or even 3u rack units.  You could pick one up and only use the audio i/o on it and end up with something pretty high quality for not too much money if you looked around, but I don't have any specific recommendations.

[TubularCorporation]

This looks promising: https://doukaudio.com/nobsound-3-in-1-out-audio-splitter-xlr-signal-switcher-selector-passive-preamp-p0079.html

 

When you factor in the cost of an enclosure, jacks and your time (assume $2-$4 per jack, $8-$15 for the enclosure, $2-$4 per switch, plus shipping and even if you have everything else you'd probably need to get a hole saw or stepper bit to drill the holes fo the XLR jacks so that's another $10-$20 depending on what you end up with, unless you get a really cheap one) that price isn't too much higher than building your own.

Edited December 9, 2020 by TubularCorporation

[manmower]

Yeah I'd found some of the Kramer switchers via Gearslutz, those are a bit much...

I also keep coming across 'Little Bear' stuff (like your eBay link, and the Nobsound site sells them too). Looks like those are about as cheap as it gets. I'm going to sift through it tonight but I'm thinking something like this should do the trick?

https://www.amazon.de/-/en/Nobsound-Balance-Passive-Selector-Splitter/dp/B07CCGV6NV

Edited December 9, 2020 by manmower

[TubularCorporation]

Yeah that was one of the ones I looked at when I was searching.  I've kind of been needing one too, but what always makes me hesitate with the mechanichal ones is the potential for switching noise, not that I monitor loud enough that it's realistically going to damage my tweeters but I've lost a midrange driver on my old stereo speakers once from something similar so I'm kind of paranoid about it now.  The Kramer stuff is too expensive, though. The Douk Audio one looks inteesting because it would be easier to repair or replace parts but on the other hand their own shot of the interior has a really obvious cold solder joint right out in the open on the upper left PCB so that's maybe not the best sign for their quality control. 

 

There's really not much that can go wrong with these if they're passive, it's mainly down to getting the one with the best quality parts you can find and afford.  If you have any interest in DIY, making one would be a pretty good first project.

[manmower]

Ended up ordering an "MC103 Pro 3-IN" over the regular MC103. The Amazon reviews were slightly more reassuring.

Now making sure I have all the right cables as I wait for it to arrive. It does seem like there isn't much to it that could go wrong but I'll believe it when I have everything up and running.

[ignatius]

i use the passive coleman one.. that's cheap and clean and balanced. 

https://www.sweetwater.com/store/detail/LS3--coleman-audio-ls3-line-selector

i use it for adding/removing the sub when working on stuff. out put of my monitor controller goes into the coleman.. then outs of the coleman go to the monitors and the sub. 

TRS into the switch then TRS -> XLR to everything.