Minimum Wattage Cab

[Bassman62]

There are 12" speakers out there by the shed-load that will handle well over 150 watts.
The days when you had to double the amp wattage in speaker wattage are long gone, in the 70s heyday of Orange voice coils were not anywhere near as reliable as they are now.
Modern developemant in technology and materials now means that voice coils will stand levels well in excess of their rated power handling.
A 300 watt bass speaker is far happier getting a good quality signal from a 500 watt amplifier than from a 150 watt that is clipping.
The downside of a high wattge single 12 is that it will be loud and possibly offensive to the ear compared to a 2x12 or 4x12 creating more volume of sound which more acceptable than loudness.

[irish_admiral]

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Modern developemant in technology and materials now means that voice coils will stand levels well in excess of their rated power handling.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">Whoa... not quite, but they should be able to handle what they are rated at, and sometimes beyond. Be prepared to field a blown speaker if you assume you can push them beyond their rating.

[VintageJon]

Here it's speaker rating = output rating X 2, at a minimum.

The classic engineering rule-of-thumb is 3X power-rating for everything.

-Jon

[Andy H.]

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by VintageJon</i>
<br />Here it's speaker rating = output rating X 2, at a minimum.

The classic engineering rule-of-thumb is 3X power-rating for everything.

-Jon
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">I'd certainly advise ideally using speakers rated 150 - 200% power rating anyway <i>for <b>valve</b> amps</i>, yes. (You may well get away with less headroom with strong drivers, but valve amps can usually easily put out more then their rated wattage, and not all speakers are as conservatively rated as Celestions have always historically been.) So <i>for valve amps </i> that is reasonable enough advice.

But I agree with Bassman62 here <i>if talking solid state amps</i>. (As I suspect he was - he tells me he's been using a big SS bass bruiser in recent years...) <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Modern development in technology and materials now means that voice coils will stand levels well in excess of their rated power handling.

A 300 watt bass speaker is far happier getting a good quality signal from a 500 watt amplifier than from a 150 watt that is clipping.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
Going with speakers of double or even triple <i>a <b>s/s</b> amps</i> rated wattage will guarantee <i>nothing</i> if you hard clip its output section. Then, like him I'd prefer to use a more powerful amp to ensure it never clips. Fed a clean signal, (even from an amp a bit above the speakers power rating), speakers will be safer then if fed from a lower wattage amp run into clipping.

Valve and solid state ain't the same, and neither are the rules you should apply to choosing loudspeakers for them. So with those qualifications I actually agree with you both!

Andy.