fEARful Equivalence

[1n3]

It's hard to deny the economy right now of how much more performance / dollar ratio you get with the 15s...

... and the ratio of performance/weight.

 

[u84six]

A 15/6 and 12/6 have very similar phase characteristics and will work fine together. Lots of people use this stack.

Doesn't phase have to do with how the speaker leads are hooked up to the power source? In other words, if you have 2 speakers and one of them has their positive and negative leads reversed, then the 2 speakers will be moving out of phase, which produces a pretty bad sound. Yes, that is a concern, but what I was refering to was the frequency response between all 3 speakers; the 6", 12", and 15". You need to send each speaker a different frequency for them to sound good together. That's why most professional 2 channel power amps have a built in crossover. Having the crossover allows for several more cabinet configurations. I hear bass rigs all the time with mixed cab types going through a single channel, and it doesn't sound very good. In fact, if they took one cab out of the equation, it would probably sound better but with a little less volume.

 

[lomo]

Another voice from the peanut gallery: IME 15/6 is roughly equivalent to 410 for functional volume at a rock gig if you have 500 watts on tap, and goes lower. The lows and mids are also cleaner. If you push more than 500 (my M9 is rated at 450) maybe a 610.

 

[thudfromafar]

Doesn't phase have to do with how the speaker leads are hooked up to the power source? In other words, if you have 2 speakers and one of them has their positive and negative leads reversed, then the 2 speakers will be moving out of phase, which produces a pretty bad sound. Yes, that is a concern, but what I was refering to was the frequency response between all 3 speakers; the 6", 12", and 15". You need to send each speaker a different frequency for them to sound good together. That's why most professional 2 channel power amps have a built in crossover. Having the crossover allows for several more cabinet configurations. I hear bass rigs all the time with mixed cab types going through a single channel, and it doesn't sound very good. In fact, if they took one cab out of the equation, it would probably sound better but with a little less volume.

I believe you're referring to polarity in the first part of your post. Which technically would affect phase response, but isn't the same thing. (someone correct me if I'm wrong)

 

[rpsands]

Doesn't phase have to do with how the speaker leads are hooked up to the power source? In other words, if you have 2 speakers and one of them has their positive and negative leads reversed, then the 2 speakers will be moving out of phase, which produces a pretty bad sound. Yes, that is a concern, but what I was refering to was the frequency response between all 3 speakers; the 6", 12", and 15". You need to send each speaker a different frequency for them to sound good together. That's why most professional 2 channel power amps have a built in crossover. Having the crossover allows for several more cabinet configurations. I hear bass rigs all the time with mixed cab types going through a single channel, and it doesn't sound very good. In fact, if they took one cab out of the equation, it would probably sound better but with a little less volume.

Phase is much more complicated than how the speaker leads are hooked up. Every speaker has unique phase characteristics as you move through the frequency response. Trust me when I say this--Greenboy endorses the 12/6 + 15/6. It's fine.

It CAN be advantageous to have two channels of the power amp.

 

[thudfromafar]

Another voice from the peanut gallery: IME 15/6 is roughly equivalent to 410 for functional volume at a rock gig if you have 500 watts on tap, and goes lower. The lows and mids are also cleaner. If you push more than 500 (my M9 is rated at 450) maybe a 610.

When I was playing in a hard rock band, with 2 loud guitars and a hard hitting drummer who thought he was john bonham... 600 watts into my LDS 15/6/1 would get loud enough to keep up with the band -- to the point that earplugs were required for most gigs. I'll never play louder than that, and my LDS cab, at best, is some degree of inferior to a true fEarful...

 

[u84six]

Phase is much more complicated than how the speaker leads are hooked up. Every speaker has unique phase characteristics as you move through the frequency response. Trust me when I say this--Greenboy endorses the 12/6 + 15/6. It's fine.

It CAN be advantageous to have two channels of the power amp.

I agree. But if the polarity is reversed, your speakers will be be moving opposite from each other, causing a not so pleasant sound.

So yes, frequency phasing is a different beast, which can usually be solved with a decent crossover for the cab (is 2 or 3 way), or a 2 channel amp with build in crossover (as you mentioned). Personally, I'd rather mix and match speakers than cabs. There are just too many variables when mixing cabs, IMO. I would never mix a 115 and a 210 cab unless I had a 2 channel power amp and crossover.

 

[steve_rolfeca]

...I hear bass rigs all the time with mixed cab types going through a single channel, and it doesn't sound very good. In fact, if they took one cab out of the equation, it would probably sound better but with a little less volume.

I appreciate your concern, but you need to do some more reading. Assuming you choose the correct models, an external crossover isn't needed with a fEarful stack.

There are frequency response plots on greenboy's fEarful site, that illustrate the remarkable uniformity of the frequency response between the 12" and 15" versions.

Besides, a lot of engineering has gone into making these cabs stackable. There's a 12/6 variant called the Cube, that's the right shape to stack on a 15/6. The cabs have also been designed so that the baffle can be reversed on the top cab. This maintains the correct driver alignment when stacking "non-cube" fEarful's in the correct, inverted position.

The midrange driver and tweeter line up perfectly when you stack a 15/6 and a 12/6 Cube (or a mirror-image pair of regular fEarfuls), like a little line array.

The phase response and dispersion with this setup is actually quite a bit better than with a matched pair of conventional cabs, where the tweeters end up several inches apart.

Here's a picture of a correctly configured fEarful 15/6-12/6 stack...