I have a 700 watt classD mono amp need to know what subs would go great with the amp?

Tons of sub combinations would work with that amp. Check if the amp is rated stable to 1 ohm or 2 ohms. It is possible that it is stable to 1/2ohm, but very unlikely. If it is stable to 1 ohm, select 2 dvc subs (4 ohms per coil) and wire them in parallell (all of the + connected to + and all of the - connected to -. If it is only stable to 2 ohms use 2 SVC (single 4 ohm voice coil) subs and wire in parallel. 700w will run a pair of 12" woofers just fine. Be sure the woofers are rated for at least 350w rms each, or you will risk damaging them. You can also wire a single sub to the amp. If it is 2 ohm stable, buy a 4 ohm dvc. If it is 1 ohm stable, buy a 2 ohm dvc. Subs I would recomend: Infinity Kappa Perfect, Image Dynamics ID, IDQ, or ID-max. Lanzar Heritage Diecast or Opti (oversized vented great sub for the $), Adire Audio (any of their lineup are great). There are a lot of other good subs out there so don't limit your choices to these. I once owned a Power Acoustik CK-12D (discontinued) and it would've imploded your head in a vented box and it sounded great doing it. Not highly regarded, but one heck of a sub. A lot of people like Kicker, Alpine, JL Audio, Rockford Fosgate, MTX, Eclipse, Pioneer & Premier, MA Audio, Powerbass (new brand, but some good street bass), Audiobahn, Visonik, Hifonics, Orion, Phoenix Gold, PPI, earthquake, SPL, Soundstream, ADS, etc. There are lots of companies that make good subs. I would steer clear of Sony, Dub (low end audiobahn), Lightning Audio Bolt, and anything super generic, your results may not be too good. I have owned a few good generic subs, but I've also seen a lot that were junk. With brands like Boss Audio (Sound Storm Labs) you never know what you're getting. Some sound good, some are not so good. They don't publicize TS parameters so it is impossible to know what you're getting. Any sub that doesn't include complete TS parameters or come from a highly esteemed line (eclipse titanium, etc.) I would not buy it, because they are probably hiding the numbers for a reason.

Well it can also depend on who the amp is made by. Some amps say that they are 700 watts and only be 200 watts, but on the other hand some amps say 700 watts and can be 1400 watts. But you can put pretty much any combo of speakers on the amp as long as they make the work a little bit.

If that is RMS than a Kicker L7 would be perfect. The Kicker's can handle 600 watts RMS.

Does anyone ever read this thing or do they just continue to ask the same stupid questions over and over and over. Need to know at what impedence....'Ohms' your amp puts out 700 watts. That way we can recommend the right speaker. If you buy wrong impedence...'ohms' on your subs you will either have it shutting off all the time or you will not get full power from your amp. Go here: http://www.caraudiohelp.com/newsletter/index.htm