The TDA7265 has an externally adjusted gain resistor network, and can be bridged for a 50 watt output on only +/- 16 volts. Thats the difference between it and the 64's .The TDA7264 is available in an easy to work with 8 pin package and the 11 pin multiwatt package. Same chips, slightly different pinout but 2 pins are not connected. Nice chips. Like he said, I'd go with the 7265 because it has more options. Cost is probably around 5 dollars each ( or less ) on digikey, but they charge a handeling charge for any orders less than 20 dollars so try and order a lot of parts from them. If your'e going to have 5.1 you might try ordering 6 TDA7265's from them, that should put you over 20 dollars. You might try what I did and call STmicroelectronics and ask for samples.
I went through the TDA7265 datasheet,yes the only difference between TDA7264A and TDA7265 is the external gain setting resistors so far im using TDA2030 which i think is very unstable.
I asked in a local shop here,he didn't have it but said he could order some for about 100 rupees(that's about 2 dollars)
anyway since TDA7265 is a two channel chip im planning to use
3 of them for my 5.1 . I think 25W/ch is good enough for my speakers which have quite good SPL
not exactly, but if you use the tda7265 in bridge mode you get 50 watts, which is a lot of power into an efficient sub
although, I'm gonna go with everyone else on here and say don't go with anything under 100 watts. A 100 watt 12 inch or 10 inch should give you good performance, if the cab is designed properly. There are a lot of DIY links out there for speaker building, check around this site as I'm new here and don't know it very well. Hope I could help
by the way I forgot to add, 25 watts per channel is VERY good for speakers.. especially sattelites that don't demand much bass, therefore technically the speakers will be capable of being a lot louder because bass really sucks up an amps power. My Marantz floor speakers will kick you in the chest with 25 watts out of this chip amp. Unless your going with full range, I think 25 watts will be absolutly fine.
Remember to order a few extras just in case you have any problems