• New Sponsor: ShipNerd, Ship Your Gear with Us... for less! Click Here.

Speaker wattage and amp output

MasterEvan07

Where's that buzzing coming from...?
Gold Supporting Member
Messages
4,494
This is a silly question...but if I have a 70W speaker being driven by a 100W head am I (potentially) damaging the speaker even if the volume is kept low? I'm still learning the relationships of all the parts of amps as I continue my journey of building!
 

capnjim

Senior Member
Messages
1,228
The potential for damage is there, but as long as you are smart, and use your ears, you should be fine. If it sounds like the speaker is farting out, or getting nasty distortion, then it might be on the verge of being blown up. But if it sounds smooth it should be OK.
Just resist the urge to turn up the amp.
 

MasterEvan07

Where's that buzzing coming from...?
Gold Supporting Member
Messages
4,494
Heh, I think the only nasty distortion I'm getting is from a lousy gain channel ;)
Thanks for the response.
 

J M Fahey

Member
Messages
2,929
It depends a lot on where you play.

At home, "honey" or neighbours will complain whenever you reach 5W (or even lower :( ) so no big deal there, but in a stage or even rehearsal studio situation, with a drummer by you, ears get progressively dulled and the amp does not seem to be "that" loud ... until you start smelling charred paper or toasted VC adhesive.
 

MasterEvan07

Where's that buzzing coming from...?
Gold Supporting Member
Messages
4,494
Thanks for the thoughts all...my primary concern was that despite the ohm resistance being appropriate the wattage was still an issue. I hate to display my electronics ignorance but my pursuit of knowledge in this field I'm so new to has left me paranoid...I can only afford expensive mistakes, uh, rarely... ;)
 

RussB

low rent hobbyist
Messages
11,157
It's a good question, but one that can't be simply answered...


First, there are speaker ratings. Some speakers, like Celestions, can usually handle more power than their rating. But to what extent? You only find out after you've blown one :(

Second, there is amplifier output ratings. The example I like to use is a 50 watt Marshall, 1987 or 2204. They are "50 watt amps" but they put out about CLEAN watts. On my 2204 that's about 4 and 4 on the volumes. Go to 5 and 5, and not you're hitting about 70 watts output. Crank it up, and you get around 95 watts!

To further confuse things, there are peaks. Slam a chord hard, and a surge of power hits the speakers, and causes it to move abruptly. When the cone moves in and out, it's called the the cone's excursion. Riff some chugga-chugga chords and the speakers are moving back 'n forth fast and hard. This is another way to stress a speaker especially if you're exceeding it's rated power capacity.

Another thing to consider is damping. A speaker mounted in an open back box may handle less power than a the same speaker in a closed-back cab. This is due to damping. The air in a sealed box acts as a "damper" and restricts the cone's excursion.

All in all, if you want to be "safe" use twice the amp's output in speaker rating. If you have a 100 watt amp, run it into 200 watts of speaker
 




Trending Topics

Top Bottom