100w but at what OHM RATING? many lower cost receivers dont support higher speaker impedence at high wattage.
it could be that they only put out 100w @ 6ohm. (if it supports 8ohm its probably only at 75-80w)
many $200+ can handle 100w @ 8ohm (which is typically about 120-130w @ 6ohm or 150w @ 4ohm)
speakers also have different wattage and impedence (ohm) ratings. whether or not the receiver will work or not depends on both values not just one.
you need to give an example of a product (link us to one) if you want any other comments.
edit:
also of note is that some receivers have a higher value when only the front channels are being used. for instance a receiver with 100w @ 8ohm might say 150w if its used with just two speakers. in...