Sim Autio Rock mono blocks.
Great detail and excellent bass.
For tight bass (and damned good performance in general) without breaking the bank, try ATI. The 1502 can be had for about $400 or less, and the bass is rock-solid. Best I've had in my system, actually.
Then there's always McCormack
I don't think you'll be able to tighten the bass up with cables and amps - not significatly anyway. You might mess around with placement.
My reaction is to get new speakers if they are the problem.
If not, you could get an audiophile quality subwoofer with a bypass filter to reduce or cut-off the low bass signal going to your main speakers.
Otherwise, what is your budget for an amp?
I disagree with the theory that amps can't tighten up the bass in a system. I went from a Yammy HT receiver to a Quad 909 and the change in bass was dramatic. Needless to say everything was a dramatically improved.
We need a bit more info. What are you currently driving the Polks with? The Rogue? Do you have a budget? What is the rest of the equipment in your system. What is your room size? Have you tried changing the speaker placement?
Aragon 2004, 4004 are a gret option. it tamed my Infinity Kappa 8s when I had them
If tight clean bass is what you are looking for, the Crown Macro Reference is extremely powerful, fast, and articulate in the bass. It will control your woofers!
The Bryston 4Bst is renowned for its iron fisted grip on bass.
Odyssey Audio Mono Block Extreems. At a reasonable price also. They box with much higher priced equipment. Check out the audiocircle forum.
Find a used BEL 1001 Mk II. It's the best bass amp in the world. If the speaker is capable of it, you'll hear it.
Pretty much anything from Sim Audio. My W5 has much tighter bass than my Bryston 4BST. Mccormack has tight bass too.
for tight bass, try Linn. their strongest pt.
This one is easy-Naim 250
Try the new Bel Canto Ref1000 Monoblocks - using these with B&W 800 and getting an extra 2 octaves . . .
i agree with sugarbrie, change your speakers.
I also agree with a speaker change. Best amp I've ever heard under $15K for controlling bass plus overall outstanding performance is McCormack DNA-500.
I am not an electrical engineer and do not understand the technical side of the numbers, but I think what you are looking for is an amp with a high damping factor. "When one amplifier's damping factor is higher than another's, that tells you that the amplifier with the higher damping factor can better control the speaker systems, and all other things being equal (frequency response, phase shift, distortion, etc.) that it is a better amplifier."
I agree with Brb9. The Bel Canto REF1000 monoblocks have a damping factor in excess of 1000. I can tell you from personal experience: absolutely amazing, stunning bass control.
perreaux 2150. that was the craziest good bass i've ever heard, even today. but the BEL recommendation is good too ;)
I agree with Landrup64. The Perreaux 2150 has a tremendous, tight clean bass. I've never heard better.