300 watt or more amp in 250 RMS cab

[JumpKing]

I have two 1*12 8 ohm cabs rated 250 RMS. Now i'm looking for an 500 watt amp. In an ideal situation this amp should give 250 watts at 8 ohm (with one cabinet) and 500 watt at 4 ohm (with two cabs connected).
However, most 500watt amps give 300w or more at 4 ohm. My question is : How harmful is a 300 watt or more amp in a 250w RMS cabinet? is it enough to be cautious with the volume knob? Or are there other more fundamental problems?

[bmc]

Not a problem at all. Not to worry.

[PhiDeck]

OP: Did you read the 2nd Sticky in Amps [BG]?:
AMPS FAQ!! Info on OHMS, Allsize RIGS-OverUnderPowerCabs DIY TechTalk-Links

[BassmanPaul]

Originally Posted by bmc

Not a problem at all. Not to worry.

Agreed, up to a point!

As always, listen to your cabinets. If they start to complain turn down!

[JumpKing]

Originally Posted by PhiDeck

OP: Did you read the 2nd Sticky in Amps [BG]?:
AMPS FAQ!! Info on OHMS, Allsize RIGS-OverUnderPowerCabs DIY TechTalk-Links

No, i'm working through it now. Thanks.

[MuzikMan]

While you're getting through the FAQ I'll add that you will be happy to know that a 300 watt amp will play nice with a 250 watt cab. If you wanted you could connect a 1000 watt head to your 250 watt cab without issues................until you turn it up too much and hear the cab complaining! The key is to use your ears.

[Aussie Player]

My practice amp for home is a Hartke 350W head that puts out 275 W at 8 Ohms. The cab I use is a Hartke 120W 2x10 box so the Wattage is more than twice the speakers rating.

It is no issue at practice volume and I have pushed it at rehearsals on occasions, but....I only turn up to the end of where it plays clean.