Need opinions on head/cab combination matching

JerryW · #1 03-30-2011, 11:13 AM

I've recently pulled some of my old bass gear out of the closet, and I've got some questions on matching an amp head to speakers. I've read enough stickys here to make my head swim, but they seem to be all over the place for a simple question.

My amp head is an old Acoustic 220 - 170 watts at 4 ohms. My speaker cab has an old Jensen 15" Vibranto with Alnico magnet, 8 ohm, 100 watts. I don't need a lot of volume but would like to get a nice, deep sound. I've also got an empty cab for two 15"'s and another 15" woofer rated at 70 watts/8ohms. I could parallel both in the double cab resulting in 4 ohms, but this might be overkill for my needs.

Basic Questions: If I double them up would I be looking at a match of 170 amp watts matching 170 speaker watts? If so, is a 1/1 match like this desirable? Being I would be driving these speakers at mid volumes, would they tend to sound good or muddy, or am I just hauling around extra weight.

What about paralleling another smaller 8 ohm speaker separated from the single 15"? Or is there some "dummy" load that if added in parallel would make my single 8 ohm speaker look like 4 ohms?

GrowlerBox · #2 03-30-2011, 02:02 PM

It's not clear from this whether you've plugged the Jensen into your Acoustic. If you have, do you like the sound and is it loud enough? If so, problem solved. There is no point in adding a dummy load, all you'll produce is heat and no additional sound output.

"Speaker watts" means almost nothing -- it's just the thermal rating of the voice coil, and says nothing about the other components of the driver and how much they can take before crapping out. Use your ears on this, not your calculator.

Can't say much about the empty cab and speaker, except that you can't just bung any ol' speaker in a cabinet and expect that it will sound OK. And always use identical speakers in a single full-range cabinet.

greenboy · #3 03-30-2011, 02:04 PM

Dummy load:

GrowlerBox · #4 03-30-2011, 02:12 PM

Quote:

Originally Posted by greenboy

Dummy load

Indeed. And just about as useful.

Is that Neil deGrasse Tyson?!