just an fyi on something that worked well for us

Installed an Edcor S2M between a sonos connect and a parasound zamp.

The need for the mono output was an outdoor zone where the L/R speakers were very far apart such that in the main seating areas mostly just one channel could be heard.

Input to the S2m was a standard unbalanced stereo interconnect from the connect. For the output from the S2m we used an RCA male to dual RCA female cable and then a standard stereo interconnect from that into the zamp.

we replaced the customer's blown speakers with a pair of paradigm rock 80-sm units wired mono.

[Link: edcorusa.com]

z

"Product is built to order." Did they have this in stock? Or how long did it take them to fire up the assembly line to make one?

Actually, I was about to say of course something like this should work, but it's GREAT to have mention of actual success with an actual product. Also, other entries on its web page make it seem like the company has other products we should look into. And will do!

Thanks.

Took about two weeks for product to reach NY from NM. I bought 3 units to average out the cost of the shipping. Got a modest dealer discount.

I posted because over the years i looked for a solution and had either never found something still being made, reasonably priced, or a science project (didn't want to make the cable referenced elsewhere on r/c).

I searched again this past April after visiting a guy's home (coached little league with him ages ago) and noticed he had installed his outdoor speakers a good 30+ feet apart. I guess i was shaking my head when he said something to the effect 'its really annoying that i only hear half the music' from his table area. Found the Edcor and decided to risk the dough.

I'm mildly curious about the internals but can't say that i understand the electronics. It has what looks like a transformer inside - is this just for the balanced output and if not what benefit, if any, would this implementation have over the DIA cable + resistors you've posted about in the past?

A timely post for me , as I have been looking for a product such as this. I had settled on this [Link: mcmelectronics.com], but the Edcor product looks good also.

It sounds like you haven't used the Monacor, but let us know as soon as you do. I am about to order one of the two myself. If one is immediately available, as it appears that the Monacor is, I would prefer to move forward with it.

Thanks for posting both of these - I would be curious to hear your feedback as well.

Have used them for years. Good, solid product.

I meant to say something about the price of the Edcor thing. IT'S CHEAP compared to making this yourself. If you just solder some cables and resistors together and cover with tape, you have a piece-of-crap looking thing that will do the job and maybe ruin your reputation. Anything involving a chassis also involves at least an hour of your time. Isn't your time worth a lot more than this costs? I hate to pay this much for something so simple, but it's cheap compared to any other approach.

As for how it works, I can see the it being a couple of resistors, one in series with each input, going to a transformer primary; the secondary of the transformer would have a resistor of, say, 20K to 50K ohms.

The first two resistors add the channels; the summed signal goes through the transformer primary to ground. The primary and secondary are isolated, so no ground loops are possible. The 20K to 50K resistor on the secondary of the transformer loads the transformer enough so the whole thing looks resistive if fed to a really high input impedance.

This looks like a winner.

And no, Fins, it doesn't plug into the wall.

Why couldn't I find either of these products in January when I searched for hours!?! Sheesh. Thanks for the links!

I received my Monacor Stereo to Mono adapter and gave it a quick test using an Episode landscape speaker with a SONOS connect as a source. My only issue was what song to use for testing. All songs that I tried I could not tell if both channels were being outputted as mono. Finally used Sgt. Pepper album and Buffalo Springfield's For What It's Worth. Product works as described. What source do y'all use to hear if it is really being  outputted as mono?

It's more simple than you'd think. Any audio signal will work.

If the combiner works: Connect a signal only to its left channel. You'll get an output. Then connect it only to the right channel. You'll get an output. That process shows that audio going into either channel comes out... so both channels will be present, proving that the thing works.

The rest of this is just me writing other stuff before I wrote the simple answer above.

Slimfoot, you're going to hate this answer: It's always being outputted as mono. The question is, does this device present the audio from both channels in that mono output?

If it only presents the left channel, that's a mono output. If it only presents the right channel, that's a mono output. And if it mixes them together equally, unequally, out of phase, with hum, whatever: it gives a mono output.

I make this boring point in favor of asking the right question to get the best understanding.

There are system test discs where an announcer tells you "bla bla bla this signal is on your left channel."

Listen to most any stereo Count Basie records or CDs. Listen to the soloists. If you hear a trumpet solo that's little trumpet and lots of echo, then you're missing a channel. Listen to all the solos.

Some amps/preamps still have balance controls. Turn 'em and see what happens to the output. Better yet, do what I said in the first paragraph.

The opening sequence of "money" by pink floyd!

Forgot about that one. Thanks.

"I Feel Love" by Donna Summer.

Nice!