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BobWire XLR1 XLR and RCA Switcher Review

Rate this switcher:

  • 1. Poor (headless panther)

    Votes: 1 0.8%
  • 2. Not terrible (postman panther)

    Votes: 7 5.3%
  • 3. Fine (happy panther)

    Votes: 41 30.8%
  • 4. Great (golfing panther)

    Votes: 84 63.2%

  • Total voters
    133
Hello ASR community, I am Bob from BobWire. Thank you to Amir for taking the time to test my XLR1! I was an engineer/director of product development at Parasound products for 20 years. I left to start my own business (BobWire) last year. The XLR1 is my newest product but I also do make an RCA only version (model RCA1), speaker level (model SPK1) and some audio sensing device to activate 12V triggers (model AAT1 & DAT1). Keeping signal integrity throughout the audio chain has been a top priority in all of my designs and I'm pleased to see that the XLR1 maintains this tradition! (check out my website bobwireaudio.com for more info). :)
Hey Bob,
Congrats on working for oneself! I just (semi) retired myself, and will pick up contract work under 1099.

I remember ~35 years ago building a switching system for blind ABx testing. There were a few complications with live switching of line level signals, and of subwoofers during elevated volumes. Back then I had rudimentary experience on dealing with unwanted transients. The typical flyback diodes solved the inductive kickback from the subs; but they introduced their own measurable and audible issues.
We expanded that system to support passive crossover development, so you could have say, 3 different capacitors to switch between.

But it wasn't pretty, the socket bases were all laid out on a wooden board with point to point wiring.
 
This is a review and detailed measurements of the BobWire XLR1 XLR switcher including support for conversion from RCA. It was sent to me by the company and costs US $270.


All of these measurements far exceed the product specs which made me read the description again, realizing then that switching is done by relays and not electronics! Still, some care has been involved to make sure that signal path is very clean. So I decided to not measure in this route anymore and focus on other aspects such as bleed from alternative channel:

View attachment 398168

So best to turn off the non-input or at least turn its level down if you are not listening to it.
Amir,

Being unfamiliar on the connections for crosstalk measurements on the AP, how are the connections/configurations made?
Is the non-injected input channel loaded similarly as if a source was connected to it?

They reason why I am curious is that when using a VNA to measure crosstalk on a multiport device, how the non-injected input port is configured matters. For many RF devices, a 50-Ohm terminator is used to simulate the loading of a signal source.
 
I have one XLR and one RCA source and an XLR1 switcher.

Is there any reason not to go RCA==>XLR cable for the RCA source and use both XLR inputs?
The SINAD was higher, not that I can likely hear it, but I have the RCA-XLR cables already.
 
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Is there any reason not to go RCA==>XLR cable for the RCA source and use both XLR inputs?
The SINAD was higher, not that I can likely hear it, but I have the XLR->RCA cables already.

Just that you'll lose 6db of gain. That may or may not matter for your application.
 
solving the integration of 2-channel and multi-channel is worth this and more.

If you run 2.x for music, you'll want the 4 channel RCA1 which also switches subwoofer lines. The XLR1 will only do L&R.

Just something I came across...
 
I have one XLR and one RCA source and an XLR1 switcher.

Is there any reason not to go RCA==>XLR cable for the RCA source and use both XLR inputs?
The SINAD was higher, not that I can likely hear it, but I have the RCA-XLR cables already.
Hello Mort,

An RCA to XLR cable (adapter) will only be using a single "leg"(signal) of the balanced XLR cable. The XLR cable is intended to carry 2 "legs"(signals), each out of phase from each other. The use of 2 out of phase audio signals allows the noise picked up along the cable to be removed(rejected) at the end, inside the amplifier. This is called CMR (common mode rejection) and is the primary reason XLR/balanced connections are used.

If you used the RCA to XLR cable it would produce sound but you would be throwing away any advantage of a balanced cable. The BobWire XLR1 will take the RCA signal and convert it to balanced, using active phase inverters. This means the output of the XLR1 will be fully balanced and you can enjoy the advantage this brings as the signal travels to you amplifier.

The 2nd reason is just as drodgers suggests, you will not get the 6dB of gain that the balanced XLR connection provides. This means, if you are using an RCA to XLR cable, the audio level would drop 6dB when you try and listen to the source with othe RCA outputs.

As you mention, Amir found the SINAD was higher using the RCA input. This would be expected because the RCA input is going through the phase inverts to produce the true balanced signal. What you perhaps are not taking into account, is that if you use RCA to XLR cable, your amp is only "seeing" half the balanced signal. This totally removes the advantages of the balanced inputs on your amp. You will also need to turn your preamp/source up more to compensate for the 6dB lower signal(adding to the SINAD). So there is a give an take here but I believe the end result will be better using the phase inverters of the XLR1 rather than a RCA to XLR cable.

-Bob
 

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If using these XLR switches with a subwoofer for 2.1 or 2.2, one needs to buy a second XLR1? Or is there another way?

The RCA1 nicely handles this.
 
Slight deviation, anyone have any experience with the Bobwire speaker switch, also looks intersesting.
 
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