Advice for recording cables please

Hello, I’m looking for a cable (if it exists) - I want to use two keyboards when recording - I’m currently using a Behringer Interface which has one RCA Input.
Is there a cable that has a duel 1/4" output to RCA Input where I can plug the 1/4" into the output of one keyboard and the other 1/4" into the output of the other keyboard going into the one RCA output of the interface.

I’ve bought a cable which I thought was the correct one but the duel 1/4" ends were red and white - I plugged the ends into both outputs of the keyboards but when trying to record Audacity picked up both sounds but you couldn’t hear them both - One was recorded on both lines of the track as usual and the other just recorded on the bottom line of the track and that’s the one you couldn’t hear, if that makes any sense.

I would greatly appreciate any help and advise!

Thank you!

Which exact interface? If your interface really only has one single RCA input then you’re probably never going to get a fair balance of 2 keyboards or great sound, feeding them into one mono input. RCA (phono) is a long-standing domestic audio connection, so usually in stereo, ie the red and white, one for each channel. If your interface has 2 RCA sockets (ie L/R, white /red) you should be okay, but will end up with one keyboard on each channel. You can at least then split your stereo track into 2 mono in Audacity and play around with the balance of the 2 and mix/pan some of each into the other channel if you wish. These or similar will do it:
https://www.amazon.co.uk/Dual-Inch-RCA-Audio-Cable/dp/B095NW5TKZ
but only as long as your are using line outs from your keyboards. If your using a headphone output, you’ll have a stereo signal from one or both which your mono cables will not properly pick up, and that your set-up really won’t cope with. A basic mixer before your interface would give you so many more options.

Thank you for the reply - The interface I’m using is a Behringer UCA222 - It has 2 RCA sockets one red one white.
I had bought the cable you suggested & I could only hear one of the keyboards the other recorded but had no sound.

I’m new to this but are you saying I have to record both keyboards in mono?

Many thanks

If you are recording the 2 keyboards simultaneously it will have to be mono, one keyboard each channel. It will also only work properly if your keyboard has (what is usual) one socket marked L/L+R mono, and the other R. (The L socket delivers a combined mono signal as long as the other socket is not connected). If you are overdubbing, and only recording one keyboard at a time, you can use both output L and R sockets on the keyboard to feed the L and R RCAs in stereo. As long as you have an Audacity stereo track and everything set to record in stereo, that should then be fine. Not sure what you meant by “it recorded, but no sound”. If it recorded correctly, there would be sound. Assuming you’re on PC, you should check in your Windows settings that stereo inputs are enabled. It’s in Control Panel, Sound, then go to the recording tab. Select the input you’re using ie your interface, then go to the advanced tab, where there’s a dropdown menu to select different sample rates and 1 or 2 channel input.

If you are by any chance using headphone outputs from the keyboard, this
https://www.amazon.co.uk/TISINO-Gold-Plated-6-35mm-Stereo-Splitter/dp/B07HFBWP87/ref=sr_1_2_sspa?crid=2RZOEVG7SRCBP&keywords=1%2F4+stereo+jack+to+phono+pair&qid=1642892835&s=electronics&sprefix=1%2F4+stereo+jack+to+phono+pair%2Celectronics%2C43&sr=1-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFNWEpWNVZSNEpERjQmZW5jcnlwdGVkSWQ9QTAyMzkxNzkyV1MzMkxLRlFLMkVZJmVuY3J5cHRlZEFkSWQ9QTAzOTgyNTEyNjNZMEs5Q0ozNDA4JndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
would let you record in stereo, assuming you’ve got the input problem sorted, but you’d be back to recording one keyboard at once to have it in stereo.

Do you have a desktop/tower computer with a “regular soundcard” or do you have a laptop? Most laptops don’t’ have line inputs. Usually they just have a mono microphone input and headphone-out.

If you have a laptop with you’ll need a USB audio interface with line inputs.

The cable you linked to has a 6.35mm (1/4-inch) plug. Regular soundcards have 3.5mm (1/8-inch) connectors.