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
Indeed, this is the only solution. They did not implement yet a decent “sum to mono” when you only have one cable connected.
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
The thing is, I don’t know if other modellers like the Helix do it in an “intelligent” way, but if you just sum up both signals (using a Y cable, or a mono block at the end), you can have phase problems for some effects.
The “right” way to do it (and maybe why NDSP did not do it yet in the QC), is for the unit to detect if it is in a mono setting, propagate to every blocks so that they know that they have to work in mono, and have a fully mono chain.
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.
Well, all has been very well explained.
It is indeed signal theory 101 
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
