Hello everyone,
I’m hoping someone can help me with a question. If I’m playing with friends and only want to carry one speaker, can I sum my stereo signal to just one output? Is there a way to do this or what is a better solution?
If I stick a mono (M) block at the end of my chain, will this automatically do this for me? Thanks for any help.
Yes, change the Output to a single output, or put a mono block at the end, either way should work
Or, you can purchase a summing cable like the one halfway down this page called Balanced Mono Summing Y-Cables with Resistors
Also found it on eBay
I ended up ordering one of the cables with the resistors. Why would you have phase problems if the same signal is being sent to all speakers?
Because your L signal can be in different phase than your R signal, leading to phase issues when combining them into one signal (for example cancellation). Even if they are in phase the summing could lead to problems because your signal strength will increase. This will most likely not happen to the whole signal because your L and R signals will probably not be equal, but that again will most likely lead to an ‘uneven’ sound as some frequencies will get louder and some will get (or seem) quieter.
Oh, I see now. But, wouldn’t that already have been evident in a separate left and right signal sent to separate speakers? Some frequencies would already be cancelling themselves out if they 180 degrees out of phase?
I think the answer is no. Because with real speakers, you are actually hearing both sides, whereas in the digital summation, the frequencies are literally canceling out the waveforms of each other.
Thanks for taking the time to explain all this!
I only recently learned this stuff, so just passing along some info.
yep that’s the way helix does it, detects that only the left(mono) plug is being used and auto sums it for you. been harping on this since day one
does the multi out do this if only 1 cable is plugged in?
Not automatically, no. If you change the Output block to a single output it will, but if it’s Multi or the pair of 1/2 or 3/4 it will not sum to mono with just one cable
Thank you so much!!!
Sorry to resurrect an old thread, but I thought I would share my summing approach, and see if others have better ideas. For our upcoming gig, the FOH crew can only provide a single mono XLR, so I am building a set of mono-out presets.
Setting the output block to Out 1 or Out 2 works fine, but I often test my presets with headphones which remain full stereo in this situation. The best solution for me to hear the end result in headphones has been adding a mono block at the very end.
Through trial & error, I found that the Jewel compressor block can be used for this purpose. It consumes a relatively small amount of DSP and still sums to mono when the mix is set to 0% (see image below). Optionally, you can drop the volume slightly to account for the +3dB summed signal, but I often do some boosting at the end anyway.
After adding this block, I recommend testing your preset for any weird phase issues. Effects like the doubler, stereo chorus, etc. can sound bad when summed. In some cases, you will need to disable those effects or use single-channel stereo (L or R) instead of summed mono.
Great info! Thanks so much.
