Same Impedance, Different Wattage

[Resonance129]

I searched for a while but couldn't find any info, so I figured I'd ask:

I want to know if hooking up an amp to a cab of the same impedance but low wattage rating will hurt my amp or cab.

I picked up my 2x12 yesterday and was prepared to purchase or place an order for 1 of 2 amps I've been researching. But the store didn't have any and the guy said they were on back order, meaning NONE of the US stores had either of these particular amps. Sounded fishy to me, but I couldn't really contest it - if there aren't any available, there aren't any available...

So I bring the cab home. It's 400w @ 8ohm. I have a small Ampeg head that's a part of my practice rig rated 100w @ 8ohm. Would hooking this small head into my 400w cab of the same impedance hurt either of them? I really want to test this cab out, but don't have an amp aside from the practice amp, but I'd hate to damage either of them...

 

[Gluvhand]

You'll be fine. The only time there is an issue is if the cab is rated lower than the head, like a 4 ohm cab into a head with a minimum rating of 8 ohms.

 

[Deezer Butler]

No.... It will not hurt it

 

[Old Garage-Bander]

Can't hurt a cab by "under powering" it.
Mythbusters should bust that myth.
Though it might be pretty boring busting that one.
I just come for the stuff they blow up after the bust.

8 Ohm cab, 8 ohm or lower amp... good to go.

Have fun playing that puppy at home!

 

[blubass]

You can run 1 watt into the cab if you wanted. The rating on the cab is power handling- it's the safe working wattage for the cab. The wattage rating on a head is what it puts into a cab.

Also, you could use a head that puts out more wattage than the cab is rated for. However, you MUST be careful and start with the volume at 0. Then, slowly bring the volume up. The cab will tell you when it has reached its limit, as it will start to chuff and fart out. This isn't recommended until you really understand what's going on, if you ever encounter it.

 

[Mystic Michael]

So I bring the cab home. It's 400w @ 8ohm. I have a small Ampeg head that's a part of my practice rig rated 100w @ 8ohm. Would hooking this small head into my 400w cab of the same impedance hurt either of them? I really want to test this cab out, but don't have an amp aside from the practice amp, but I'd hate to damage either of them...

This seems to be an issue of continual confusion here on TalkBass, i.e. the power-handling capacity of the cab(s) vs. the maximum wattage of the amp head..and the fact that you don't need to match the two measures, number by number. I'm sure there must be a thread on it that's been stickied here on the Amps & Cabs forum.

MM

 

[Resonance129]

Cool. Good to know.
I had a feeling it would be fine, but didn't want to chance it.
Turns out, the cab is Speakon only, and the practice amp head is 1/4" only... So I'm just gonna have to wait until I can get the amp.

Thanks for all the replies.

 

[ezstep]

There are speakon/phone jack adapters, and any mom&pop music store can quickly (as in 3 minutes) make you a speaker cable - speakon on one end, 1/4" phone on the other.