There seems to be a bit too much latency to hop 2, is that local to you (cable modem) or not ?
Make sure that you keep the wireless router away from possible sources of EMI, i.e. at least 1 foot away from the cable modem, power supplies, fluorescent lights, etc.
Also, I'd disable "mixed" G and N mode in the wireless router and change it to "N"-only for best throughput. Is the client using a "N" NIC as well ?
Check the Bits/Bytes calculator here: http://www.speedguide.net/conversion.php and note that there are different classes of "N" wireless products. Some are 150Mbps, some are 300Mbps, and only a few work up to 450Mbps. Many wireless NICs only work at the lower "N" speeds. With that in mind, a 150Mbps NIC is capable of ~17 Megabytes/second in both directions, 300Mbps = ~35Mbytes/sec...
I hope this helps