I Need Help Settling An Argument With A Friend

[Bass Jim]

Could a 100 watt Fender Rumble Amp be able to power a Behringer BB4X10 cab which is rated at 1200W? We've been arguing about this for a while and still haven't found a concrete answer.

[paul_s]

Yes, as long as it has the proper speaker out impedance, ie, 4 or 8 ohms.

[tmut]

Technically? Yes
Practically? Not really

[darthplagis]

does the amp have ext speaker outs?

[electracoyote]

Originally Posted by tmut

Technically? Yes
Practically? Not really

I have always understood that you need to send a healthy amount of wattage to a speaker, approximating its capacity, and there are negative consequences for underpowering a speaker.

So, is it not only impractical, but dangerous to do something like this?

[Febs]

Originally Posted by paul_s

Yes, as long as it has the proper speaker out impedance, ie, 4 or 8 ohms.

According to the manual, it's rated for a 4 ohm load. However, there is no speaker out, so there is no way to hook up an external cabinet.

[tahbass]

I run a 300W tube amp at 4 ohms into an 8x10 1200W cab, also 4 ohm. So I would tend to say yes. However, I'd be reluctant to do this if the amp and cab wattage ratings were switched (1200W amp into a 300W cab = 'splosions).

[billfitzmaurice]

Originally Posted by electracoyote

I have always understood that you need to send a healthy amount of wattage to a speaker, approximating its capacity, and there are negative consequences for underpowering a speaker.

Myth.

So, is it not only impractical, but dangerous to do something like this?

Not in the least. A 100w amp won't drive a 1200w rated cab to full output, but that's hardly dangerous.

We've been arguing about this for a while and still haven't found a concrete answer.

Now you have.

[dmusic148]

Originally Posted by electracoyote

I have always understood that you need to send a healthy amount of wattage to a speaker, approximating its capacity, and there are negative consequences for underpowering a speaker.

Dude. Seriously? Tell me you're kidding.

[HolmeBass]

Originally Posted by electracoyote

I have always understood that you need to send a healthy amount of wattage to a speaker, approximating its capacity, and there are negative consequences for underpowering a speaker.

So, is it not only impractical, but dangerous to do something like this?

My experience, and the published use cases of many manufacturers, suggest that this is not the case - you can't really underpower a speaker cabinet. You can have too little amp to properly cover a gig, but that's fundamentally different than "underpowering a speaker cabinet". This is my opinion, and this is definitely the topic of Holy Wars, so I'll leave it right there at that. I am positive others will disagree.

[BassmanPaul]

The question is not whether you can but more why would you want to. The Behringer cabinets have a terrible reputation on this site.

[SnakeKappele]

Originally Posted by electracoyote

I have always understood that you need to send a healthy amount of wattage to a speaker, approximating its capacity, and there are negative consequences for underpowering a speaker.

So, is it not only impractical, but dangerous to do something like this?

The problem is not in under powering the speaker, it is in overdriving the amp to the point of clipping.

[RickenBoogie]

Which has nothing to do with the cabs rating. And to the op, your Rumble is a 4 ohm min amp, connected to an internal 4 ohm spkr. That's why there's no speaker out, the amp won't support it.

[lunarpollen]

I wonder if people who worry about underpowering a speaker always turn up the volume full blast on all of their audio gear, lest the speaker be damaged or destroyed by not giving it enough power... heehee

[SnakeKappele]

Originally Posted by RickenBoogie

Which has nothing to do with the cabs rating. And to the op, your Rumble is a 4 ohm min amp, connected to an internal 4 ohm spkr. That's why there's no speaker out, the amp won't support it.

Actually, the amp will support it. Just not both the internal speaker(s) and the external. Disconnect the internal speaker(s) and connect the cab. The original question said nothing about powering the cab AND the internal speaker(s).

[BigOldHarry]

Originally Posted by tmut

Technically? Yes
Practically? Not really

That sums it up nicely.

[electracoyote]

Originally Posted by lunarpollen

I wonder if people who worry about underpowering a speaker always turn up the volume full blast on all of their audio gear, lest the speaker be damaged or destroyed by not giving it enough power... heehee

YES! That's exactly what I do! No wonder I keep getting kicked out of bands.

(kidding)

I think that sentiment goes back to my old home stereo audiophile days, and even still today, I will drive speakers rated at 75 watts with a 300 watt stereo amp. Potentially, that's 150 watts per channel into a 75 watt speaker. Yes, it means you can blow the speaker, if you're an idiot, but the conventional wisdom was if you don't push too hard, it's better for the speaker.

But now I'm not so sure, because I am giving in to peer pressure. Now I have low self-esteem. Now I'm going to go eat worms and chew my nails until they bleed.

[billfitzmaurice]

Originally Posted by SnakeKappele

The problem is not in under powering the speaker, it is in overdriving the amp to the point of clipping.

Also myth. What do you think guitar players do to get overdriven tone? Know whereof you speak before you post.

[Tony G]

Originally Posted by billfitzmaurice

Also myth. What do you think guitar players do to get overdriven tone? Know whereof you speak before you post.

I know it has been said many times before in other threads, but could you please specify once again the factors that would lead to damaging a speaker?

[billfitzmaurice]

Originally Posted by Tony G

I know it has been said many times before in other threads, but could you please specify once again the factors that would lead to damaging a speaker?

There is only one: Overpowering.
http://billfitzmaurice.info/forum/vi...hp?f=10&t=1886