Second sub connection

A basic question but then again basic is the limit of my audio knowledge. I currently have a Schiit Freya preamp with two rca outputs. One output is running a pair of tube amps the other was for an older Quad subwoofer with rca L and R inputs. I just purchased a second sub (svs pb2000) with the same inputs. I had a brief conversation with SVS and was told to run a pair of cables to each sub with splitters.
i have an old pair Radio Shack Y splitters male to female and could put one in each channel of the second output and run a pair of cables so each sub is getting a right and left that correct or should I run one sub only left and one only right?
Second...could I use different splitters on the sub end (dual male to one female) and run one cable each from the the preamp L and R to the subs.
The second application would save me some money on cables. I already have a pair of 12 foot cables that were to my first sub, the second sub would need a 22 foot run. So I thought if I took one of the 12 foot cables and patched it to a 10 foot cable I could run that to new second location if I were to split at the sub end. Not knowing the difference because of my current cables one is coded red for right and the other black for left (normal) so is that going to present an issue separating them. Don’t want to compromise on the connection to save money but I would like to understand better how this works.
Thanks for any responses that might shed some light 💡.

Do not have intimate knowledge of your subs, but usually there is a mono option, usually the left channel being mono.  

If so, simply connect the left channel output of the preamp to the mono of the left sub, connect the right channel output of the preamp to the mono of the right input.

That's my best shot.  If anything catches fire, I recuse myself and accept no responsibility. 
That is how I run my 2 Hsu Subs.
Thanks for the responses. I have an LFE on the new SVS but not on my older Quad. So would putting the y splitters on the sub end and running a single cable to each sub accomplish the same thing. I don’t need to feed a left and right channel to each sub?
I just run a single cable to each of my two subs from a pair of y splitters at the preamp end.
Sounds fine to me
Uberwaltz...sorry not to pick up on this right off but the y splitters I have would leave 4 open ends plugging one in each channel off the pre, how do we get a single cable going to each sub. Would running a single cable out of each of the preamp channels into a y splitter feeding L and R on the sub end create a problem?
Sorry my bad I did not explain my setup.
I only need y splitters at preamp end because I am also sending a tape out signal to tape decks.

In your case I would just run one cable from each l&r pre out to each sub.
I would just go into one input on each sub and forget the y splitters altogether.
However if you have them you could try both methods although I honestly doubt you will hear any difference feeding both l&r inputs on the subs.
Thanks for the help. I will try your recommendation and just buy a single cable for the second sub and skip the splitters. Just as last bit of info. Can I take one of the 12 foot cables that I will have left after removing one from my current setup and join another length of matching cable to make my 22 foot run or just get a full length cable. Would there be a sonic difference I could detect if patched going to the sub with such low frequencies?

admittedly, i was confused there a bit too. splitters or ‘Y’ cables introduce another segment of signal loss usually less than 3db, but loss of 1 or 2 for sure.

then too therre is the introduction of differing cable materials and in this case connectors and or splitters are different ICs essentially.

eliminating signal loss is always a very good idea. albeit, one will figure the gain of a pre or line stage, and or an amp will forgoe this loss in connectivity, I’d avoid it if possible.

I might be picking nits here and one or two db of signal loss at one sub might be undetectable . dunno.

it will help keep the signal path more secure though and likely prevent the coupler from getting unplugged inadvertantly.

as this is for the lowest octave chances are there won’t be any overtly audible discrepncies.

+1 on using the ‘left’ input on each sub regardless the output on the pre, ‘L or R’.

i would say get the sub info from as far down the signal chain as is possible, i.e. the pre in your case simply for timing sake. ten ft ain’t a lot of conductor so the 22ft run ought not show up sonically as a deleterious issue.

good luck.
Your preamp may have a pair of XLR and/or two pair of RCA outputs.
The SVS subwoofer may have a pair of RCA inputs and a pair of RCA outputs.

If so, simply connect a pair of interconnects to any of the three sets of the preamp outputs to the SVS's RCA inputs and another pair of interconnects from the SVS's RCA outputs onto the Quad's RCA inputs. 

Monoprice or Blue Jeans Cable can provide long custom length runs of cable at reasonable prices. Have fun with it.