Spkr Cables for JMR Trente

Does anyone have any suggestions for speaker cables for the Trente's? My friend just bought these and is using her old single run Analysis PLus 12's and something is missing. they sound a bit congested and somewhat thin. Any ideas? Thanks. Oh, her amp is a YBA W202 integrated and the source is the Marantz 9006 dvd/cd.
I'm assuming the speakers are broken in. If that's the case, I would suggest that you fix the problem instead of buying cables. Using cables to fix a problem like this almost never works. You should be able to get your system sounding good with basic, inexpensive cables first. If you can't do that, the problem, most likely, lies elsewhere.

I see only 2 solutions here. The first is to find out what component(s) are the root of the problem, and replace them now. The 2nd way is to buy cables now and then find out what component(s) are the root of the problem, and replace them later.
Agree with Zd542

The disappointment from lack of system synergy is likely much more than just a quick cable swap.

The Marantz as your source would be my first suggestion.
The JMRs and YBA are very good gear respectively that I have heard personally. A step-up to a high-end CDP or a high-end DAC to audition and re-evaluate would be my first step.

YBA recommends their own cables and JMR work well with Crimson. These are important but only as the next incremental step after assessing a need for step-up in source at the front -end.
I use ClearDay Cables with JMR Offrande Supremes -
Thanks for the responses. The Marantz is actually the 9600 which I've heard on other systems sounding decent. I'll swap in another player and see what happens.