I have been renting a Cisco DPQ 3925 modem from cox for quite sometime. Tired of paying the $7.99 per month so I want to buy my own. I have several people pulling from Wifi. My question is could I / should I buy a dual modem or should I just buy the same model I have now? I do have to re set this one a few time a week. Thanks
That is an eMTA with telephone so I don't think you can purchase it. Either way its a single band gateway. Do you still have phone service? If so, my recommendation would be to swap that for the DPQ3212 which is free from cox as long as you still have phone service. Then get a separate dual band AC router. This can potentially improve wifi coverage
I suggest separate router/modem. You usually get a better modem and a better router, and that way if one component fails or if you want to upgrade one but not the other, you can.
Cable modem firmware can only be pushed by Cox, and this applies to combined Cable modem/wifi router devices too. By separating them you can at least stay up to date yourself on the router side.
Stay away from modems that use an 'intel puma 6' chipset - they have some latency/jitter issues. Search online for 'puma 6' for more info.
Good modems with Broadcom chipsets include Arris SB6183, Zoom 5370, Motorola MB7420, or Netgear CM500/CM600. All of them are 16x4 except the CM600 is 24x8 - I consider the CM600 the best value right now as its only a little more than the 16x4 modems and can be had for $90 on newegg/amazon.
If you want to "future proof" you can get the Arris SB8200 modem for $200 which is DOCSIS 3.1 compatible. You can buy it from Arris directly:
http://shop.surfboard.com/sb8200-surfboard-cable-modem/
For picking a router, check out reviews on https://www.smallnetbuilder.com/
