Speaker wattage to amp wattage ratings

[Shack]

So, if I have a 100 watt amp, and need speakers, do I have to buy a speaker with over 100 watt rating.....and if I use 2 speakers, or 4, what wattage ratings do I use?

I think a marshall cab uses like 4 speakers that arent 100 watts

[John]

2 100 watt speakers gives you 200 watts power handling. Pretty sure it doesn't matter if they're hooked parallel or in series. And your speaker rating (total) should be about double your amp wattage, as when things start to distort the power handling goes down on the speaker. Square waves hammer harder than nice smooth sine waves.

[Shack]

so 4 celestion greenbacks in a cabinet is 100 watts total, I think

[jjasilli]

For guitar amps: the total speaker wattage should equal the "output" in watts  of the amp.  N.B.: if the guitar power amp is overdriven, then double its wattage output rating.  So a 50W amp overdriven should be considered 100W.  So the speaker(s) should be 100W.


For hi-fi, generally the amp should be 2X the continuous wattage rating of the speakers.  Here we're working backwards.  The speakers should be of sufficient wattage to fill the room with sound at the loudest desired volume level.  The amp is 2X that wattage so that transient spikes will remain clean.  Amp distortion can blow tweeters.

[PRR]

*For Guitar Amplifer* speakers should be rated by maximum amplifier power. Say you have that 100W amp, you certainly want to buy at-least 100W of Guitar speakers. An EVM, or four 25W, or two 50W.....

Going double is not bad, though I think most reputable Guitar Market manufacturers take all-out square-wave into account.

The usual 1"-1.25" coils with modern glues are good for 25+ Watts. 50W and up suggest 2" coils, though modern adhesives and other cooling techniques mean you can't really go by gross size anymore. EVM's 2.5" poly-epoxy *will* take 150W of gross heat for hours. As 100W amps are rare and 100W in one cone is not optimum, smaller ratings are more popular.

As said, Hi-Fi "never clipped" figures different. We often use 100 Watt amps with speakers that would melt with more than 10 Watts for more than a few seconds.

[Ed_Chambley]

Take into account the tone you prefer as well. Foi instance, i have a 30 watt weber ceramic in a bassman 5f6a. A 40 watt amp, but I was wanting the speaker to move and give tons of punch since a single 12.


I have also burned through voice coils on 2 celestion blues playing a 80 watt amp. I did not push them and was playing clean, but usng a es335. I had to get a original recone done on them.


Do I still do it, sometimes sure. I do always have a extenion cab with a ev loaded. I really like early excursion to move air. I have paper cone 12 no dope weber 15 watt in a princeton reverb. I have burned it 2 times and weber recones for 25 dollars. The difference is worth it to me. Much easier to get the cranked amp tone.


I have found 10 inch speakers to need to follow the 2 times rule. Also if alnico ceramic mix I find it best to use lower watt alnicos with ceramics. Like 20 watt alnico with 30 watt ceramic. This gives the alnco compression which have a smoother  high and retains a nice low mid from the ceramic.


Speakers are IMO the most overlooked things. I just got a pair of Eminence AlNiCo that were designed for the new fender tweed twin and they reallu knocked it out of the park with these for a vintage tone.


If you want them to last double the wattage and run them hard and long. When they loosten up they will sound great, just like an ols marshall cab.

[Shack]

Cool, thanx for the responses. Right now im playing through the Fane in a Crate G-60 SS amp, since its the only 4 ohm speaker I have while waiting on cab and speakers. I believe its 120 watt, since the usual speaker that the Crate came with from factory is a 120 watt Celestion, and this Fane came from factory.

I was asking because im trying to figure out what setup ill want....1 x 12( for weight) 2 x 12 or 4 x 10 .

Thinking 2 x 12 would be best , and I seen alot of celestions on EBay for less than 75.00 only alot of them were 25 or 30 watters

[Beezerboy]

check Musicians Friend, they got some stuff on sale.  I've been using the "Warehouse" brand.  well built, great sound.... 70 bucks