#120903  by Stella Bloo
I have 2 K-110's in an HT cabinet rated at 4 ohms. Speakers are rated at 40 watts each. I currently run an SMS into a Rocktron Velocity using only one side @150 watts. I am careful not to crank the power amp as I am quite worried about blowing my K-110's. For a bedroom rig, I have an Emery Microbaby 2 watts and can bypass the the preamp and use the SMS as the preamp and the Microbaby for power amp. My question is, am I harming the 2 K-110's by running such low power through them? Someone told me that you can harm a speaker by not using enough power?

 #120918  by playingdead
Most people will tell you that underpowering a speaker can't possibly cause damage to it, and I think that's the case here. Whether it will sound good is another matter.

There is a scenario where pushing an underpowered amplifier too hard can cause the amp to clip and go way over its rated output, with a waveform that could potentially damage a speaker. But when you're talking about a 2 watt amp and a 40 watt speaker, that seems very unlikely to occur.

I would hook it up and try it out, gently. If it sounds good, and you're not absolutely cranking the little amp up, you are probably okay. Others will weigh in, I'm sure.
 #120938  by Stella Bloo
Thanks Vic,

And yes, those are the K-110's I bought from you and could not be happier, just don't want to do anything to hurt those precious babies!
 #120967  by JonnyBoy
I really can't see a 2 watt tube amp hurting your k110 JBL's, but they are probably not the best match for it either because of their high wattage. On a daily basis we put a small amount of wattage through our speakers in our practice amps, and they seem to last just fine. I mean, who really cranks their amp to 10 everyday at full wattage? I would try using just one with the microbaby if I was at the helm, thats all you really need for that application anyway. Your going to be using an SMS preamp with a hotter signal than the microbaby's pre also, but I dunno what that extra signal translates to in wattage out of the power side. I assume its a bit louder (or could easily be) when you hook the SMS up to the microbaby? My old Mosvalve combo amp manual said the wattage was 100 watts but with both (pre) tube drivers stacked it could be significantly more than 100 watts that it could possibly blow the speaker. Again, I am not an amp expert, that could be the square wave (distortion) causing that issue. I really don't have an absolute answer on how all that equates between pre signal and power side signal.

With your rocktron, I would be very careful at loud volumes, but I wouldn't be afraid of using the cab with it. 150watts could blow those original cone vintage speakers if it gets away from you, but that would be at a high volume. At lower volumes I wouldnt be scared to play through both of them at say 1/2 volume clean (be sure not to unplug your guitar with the amp real hot).
I have seen 40 watt tube amps a 25 watt speaker in them so, you just have to be careful on the higher wattage amp to lower wattage speaker. But, that rocktron set up is probably more suited for that 2x10 cab then the microbaby, so you could use them for both really!