Folks!
An embarrassing question: are there "proper" downmixing RCA cables out there to buy? My mixer board (A&H Zedi 10FX) does not seem to have a mono output or a way to downmix to mono for the monitor. I am using a single 15" PA speaker as a monitor, and it only has a mono RCA input.
I think the proper way to downmix is to connect the two RCA channels together via 100k resistors but I cannot tell if such cables exist! There are plenty of cables on Amazon that look right but I cannot find any info if they have resistors or are just soldered together.
I wouldn't terribly mind making one myself but I am not sure how to make it nice and sturdy. And I don't want yet another box for that.
Does anyone know if there is maybe a special "code word" in the description of the cable that would indicate a proper downmixing cable? Or a regular cable would be good enough? Or, perhaps, a good way to make such a converter myself that would be sturdy enough not to fall apart soon?
Thanks!
P.S. Right now, I am just using one of the stereo channels since I usually just play guitar through it. But that occasionally leads to confusion: once my daughter was playing along to a song, and she was complaining that one of the guitar parts was missing altogether. It took me a while to realize that it was recorded completely on the other channel. 🙂
An embarrassing question: are there "proper" downmixing RCA cables out there to buy? My mixer board (A&H Zedi 10FX) does not seem to have a mono output or a way to downmix to mono for the monitor. I am using a single 15" PA speaker as a monitor, and it only has a mono RCA input.
I think the proper way to downmix is to connect the two RCA channels together via 100k resistors but I cannot tell if such cables exist! There are plenty of cables on Amazon that look right but I cannot find any info if they have resistors or are just soldered together.
I wouldn't terribly mind making one myself but I am not sure how to make it nice and sturdy. And I don't want yet another box for that.
Does anyone know if there is maybe a special "code word" in the description of the cable that would indicate a proper downmixing cable? Or a regular cable would be good enough? Or, perhaps, a good way to make such a converter myself that would be sturdy enough not to fall apart soon?
Thanks!
P.S. Right now, I am just using one of the stereo channels since I usually just play guitar through it. But that occasionally leads to confusion: once my daughter was playing along to a song, and she was complaining that one of the guitar parts was missing altogether. It took me a while to realize that it was recorded completely on the other channel. 🙂
100k is way too high, that will completely attenuate the signal. Something like 100 ohms will be a nice balance of attenuation, op amp protection, and noise considerations.
EDIT: If you have to buy a cable, then just a Y cable should work. It is pretty simple to make a cable with series R, since a single resistor will easily fit inside the connector hood.
EDIT: If you have to buy a cable, then just a Y cable should work. It is pretty simple to make a cable with series R, since a single resistor will easily fit inside the connector hood.
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Are there any standard cables that are better suited for such mod? Like, easier to open, not molded, cable kept in place in some way etc?
You say you "don't want yet another box", but perhaps you should consider this:
https://www.amazon.com/Generic-SPRO...28942925&sprefix=rca+stereo+to,aps,281&sr=8-6
https://www.amazon.com/Generic-SPRO...28942925&sprefix=rca+stereo+to,aps,281&sr=8-6
Yes, this is exactly the kind of a box that I would like to avoid. 🙂 I'd rather solder in some resistors into a cable. Thank you though.
That's easy enough to do, but instead of buying a prepared splitter cable obtain three RCA phono plugs and a length of twin screened cable.
Solder a (physically small) 1K resistor to the centre pin of each of the stereo pair of RCA plugs.
Connect the signal wires in the twin screened cable to the free ends of the resistors.
At the mono RCA plug end connect the left and right signal wires together at the plug's centre pin.
Connect the screen wires that come from each of the stereo RCAs together at the barrel of the mono RCA plug.
(If you should experience a hum, disconnect one of those screen wires.)
P.S. Choose thin twin screened cable. Thick cable may not fit into the single (mono) RCA plug.
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Galu's diagram sounds like what you need. See Rane's note below on 'Why Not Wye?' They explain how to to connect a stereo cable to mono without causing distortion or overloading problems. Figure 2 is the same as Galu's diagram.
I believe the inclusion of a large value resistor (10 K) between the junction of the 1 K resistors and ground is intended to increase the level of the signal available at the mono output.
I have found the convertor circuit to work satisfactorily without this resistor. However it is easy to include it in my instructions in post #7. Just connect it straight across the terminals of the single (mono) RCA plug.
I have found the convertor circuit to work satisfactorily without this resistor. However it is easy to include it in my instructions in post #7. Just connect it straight across the terminals of the single (mono) RCA plug.
Just a little side-note regarding 'stereo to mono combining/joining' >
Some stereo content is mixed with intentional channel-to-channel phase inversion of an instrument or effect to create a 'super wide'
sound outcome. Infact, all mixes that were made for Dolby Prologic use this technique to create the rear channel output.
Using the normal cables described above creates a volume reduction or cancellation of signals mixed in such a way.
The solution for combining channels in this scenario is to introduce opposing L/R comb filtering prior to the 'joining lead'.
Some stereo content is mixed with intentional channel-to-channel phase inversion of an instrument or effect to create a 'super wide'
sound outcome. Infact, all mixes that were made for Dolby Prologic use this technique to create the rear channel output.
Using the normal cables described above creates a volume reduction or cancellation of signals mixed in such a way.
The solution for combining channels in this scenario is to introduce opposing L/R comb filtering prior to the 'joining lead'.
You may believe what you like, but it will certainly have the opposite effect.
What kind of PA speaker only has a single RCA input? It should XLR inputs or at least 1/4" TS inputs.
In case there are more inputs available on the speaker the simple solution you may have overlooked is to just connect both mixer outputs to the speaker and let it do all the summing.
If you can use 6.5mm or XLR jacks it's easy enough to fit resistors in their casing to make for a clean and neat cable
Going back to your original post, does your mixer have Aux outputs? If it does then send the left and right feeds to the same Aux and job done no need for a special cable.
There is an AUX output on quarter inch jack socket:
https://www.allen-heath.com/content/uploads/2023/06/ZEDi-10FX-Technical-Datasheet.pdf
Out there, are plenty of such cables, but I'm afraid they aren't exactly "proper", as a passive way.
I'm not an expert, but I guess there are more ways to reach a goal, but only one is the true proper one.
In other words, it depends from your needs in terms of resulting SQ.
The matter does not seem at all simple to solve for reaching best sound results and the following link may be of interest
https://www.sonible.com/blog/stereo-to-mono/
However, if you had low expectations then maybe, just maybe, the resistor cable might give a some result.
But if you want higher performances I think you should look elsewhere. IMO
In my humble opinion this is the real issue here.
You don't want another box, but maybe for good sound results you have no alternatives to an active circuit IMO
Anyway, since we're on a DIY audio forum and even if I've not tried the following one (just as an example), it seems to have given good results to more than one user. 😉
https://www-iz0kba-it.translate.goog/stereo-mono/?_x_tr_sl=it&_x_tr_tl=en&_x_tr_hl=it&_x_tr_pto=wapp
Make your proper choice. 🙂
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A good point, I should have been more specific. There are other inputs, it's just none of them are stereo, except, possibly, bluetooth.
My speaker is a single Samson RS115A. It has RCA, XLR, 1/4", and BT, I just was not sure if that would help. Good point on the bigger size of XLR and even 1/4" though!
So, here is the porn shot of the back side of the speaker with all its hookups... Actually, now that I am looking at it, I feel stupid: there is an AUX IN in the BT box right there, it is probably stereo...
You are thinking about the problem incorrectly. Cables do nothing but connect things together. It is the component(s) that the cables connect together that will do the "mixing" that you desire. It doesn't matter how many resistors are included with the "cable", either. This is just modifying (by adding to) the circuitry in the input and output stages of the equipment that the cable is connecting.
You should instead be thinking about how you can configure or build your cables so that the equipment you have or will use can properly mix the signals together as you desire.