Reply to System hook up question, 1/4 in ch to RCA

Last week I played my first bar gig in 7 years, after strictly being a wedding and event DJ, and I ran into some problems.

It was a small bar, that had a NAD home amplifier. The bar own said there's two cables in the back and I just hook them up. So I found two female XLR's just as he said. I brought my Kontrol S2, and got my 1/4 male (the main outs on the S2) to XLR male cables and plugged them into the cables hanging out of the DJ table, only nothing came out. My system worked for sure, because I got sound out of my monitor and the headphones.

They insisted their system worked, and people had been using it only days prior, so I took a look. They had a DI box (is this the correct term? I thought DI boxes were only used for mix inputs?) in the chain so it went 1/4inch out of my S2, into an XLR which ran the length of the bar. The XLR's plugged into a DI box, which I believe had 1/4inch to RCA cables with the RCA's going into the back of the amp (tape input).

Am I missing something here? I tried everything and couldn't get any sound out of the house system. One of the guys there said I could put a second DI box in the chain, so that my outputs went into the DI box, had XLR's coming out of them, and then going into another DI box which had RCA's coming out and going into the amp.

I'm not positive, but having two DI boxes didn't seem right.

Can someone out there shed some light on this?

Thanks.