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Vertical cab stacking---the only way to play

#181
I'll address the "split across stage" bit from personal experience, and it has little to do with LF cancellations or comb filtering really. One of my guitarists tried this, and wanted me to as well. I didn't, but he did. And what did I have? Even MORE loud piercing guitar assulting my ears from close by, made it tougher to hear my own rig, my own personal monitor.

And talking to guitarists, all other sonic degradation aside, I'm sure if I placed a bass cab over by a guitarist that he'd be wanting to hear a lot more of himself and turn up (even more than usual which is already often too loud) to compensate. There goes the stage mix.

Drummers? Just aim the rig slightly their way, or get the cabs in closer to them and/or a little behind.
 
#182
i found this in another thread that sort of answers my question, but please engage (much knowledge to be learned):

Originally Posted by theshadow2001
I maybe wrong on this but I thought that if you split cabs to opposite sides of the room you loose any coupling effects that can be gained by stacking. So if you have a 600 watt amp outputing 300 watts into each cabinet you'll have a total of 600 watts whilst they are stacked. If the cabs are split, the overall volume will be quivalent to having 300 watts.
Again someone feel free tell me I'm wrong on this one

response from BillFitzmaurice:
If the cabs are separated there will still be coupling, but only at frequencies where the two cabs are in phase with each other at the listener's position. Where they are out of phase at the listener's position they will cancel each other out. In between the two extremes they will either add or subtract from each other at the listener's position, and since the listener's position is variable so is the frequency response throughout the room. This phenomenon disappears once you get a few wavelengths away from the source, so it isn't very obvious for anything but the bass, due to the long wavelengths of its content.
 
#184
Johnny Mack said:
greenboy i agree with the volume war deal, but in a perfect world, if one cab was enough to hear yourself on one side, and the guitarist on the other doesnt feel obligated to turn up, what real world audio issues would we be seeing (hearing) happen?
Click to expand...

You pretty much ansawered your own question with the quote you pulled up from the past. Long waveform content is degraded by distance unless the distance is greater than the combined length of the longest waveforms. In the case of a low E fundamental that would be about 56 feet. Its octave overtone would still require 28 feet of separation - or close coupling - to not be compromised in various listening positions.
 
#186
People really don't interfere with the propogation of LF waves.

And yes, not only does the listener and cab positioning interact, but to further complicate and degade the control of it, it interacts with BOUNDARIES. See at least one of my posts in this thread - briefly describing reflections not in phase, room modes based on room dimensions, etc.
 
#189
billfitzmaurice said:
Myth. If that was the case headphones would not work. :D
Click to expand...
Well then that's one of the best myths to ever get around because I've heard it said by audio professionals for years. Here I always thought the reason you could hear the bass in headphones was because of acoustic coupling with your head creating it. Headphones or earbuds always sound bassier when you mash them into your ear and less bassy when they're half on. So is that just a result of the passageway to your eardrums being less direct when they're half on?
 
#190
Sorry I don't have time to read the full thread got through 80% of it though will finish it later anyway

How does comb filtering really affect todays bass player.

I have an idea of what it is and what causes it. But so what if your missing bits and pieces of your sound as you move around the speaker?

Does comb filtering affect my ability to here myself clearly?

Does it effect the ability of my band to here me clearly?

Does it effect the ability of the audience to hear me clearly?

Its it more a tone thing than anything else? Will I just hear different tone as I move around my 4x10?

What is so detrimental to live sound in terms of comb filtering?

I have a 4x10 and 1x15 cab. How can I objectively demonstrate to myself the effects of comb filtering from my 4x10?
 
#192
theshadow2001 said:
Sorry I don't have time to read the full thread got through 80% of it though will finish it later anyway

How does comb filtering really affect todays bass player.

I have an idea of what it is and what causes it. But so what if your missing bits and pieces of your sound as you move around the speaker?

Does comb filtering affect my ability to here myself clearly?

Does it effect the ability of my band to here me clearly?

Does it effect the ability of the audience to hear me clearly?

Its it more a tone thing than anything else? Will I just hear different tone as I move around my 4x10?

What is so detrimental to live sound in terms of comb filtering?

I have a 4x10 and 1x15 cab. How can I objectively demonstrate to myself the effects of comb filtering from my 4x10?
Click to expand...
To answer your questions in order:

Any improvement in your sound is always a good thing.

Yeah, so what if people in the audience can't hear you in one part of the room and they move 5 feet and they get blasted? People have been playing that way for 30 years. Who cares?

Probably not if you stand directly in front of the amp. If you hop around the stage, then it will.

Yes. I have stood in front of my amp and thought it sounded fine, then I'll move to the far side of the stage by the keyboardist and I'll be blasting him out. Eliminating comb filtering means you'll sound pretty much the same everywhere on stage.

Yes, if you're using your amp for the audience to hear. If you use a PA, then it's the soundman's problem.

This is a question I'm not qualified to answer. People hear things differently. It may mean zip to you. But just moving my top speaker two inches from the center of the bottom speaker made a noticeable difference for the worse to me.

You'd like everyone to hear you the way you hear yourself, right? If you're comb filtering and phasing your signal out, people will hear you differently depending on where you stand.

Hook up your 4-10" to a long cable or wireless, then walk as far as you can in either direction. Then hook your 15" cab up by itself and do the same thing. Listen for the differences. This demonstration works much better in a large room.
 
#193
Johnny Mack said:
I have never done this, but am just curious. a few questions:

while i agree my two 112s sound great stacked on axis, is it really not practical to split them approx. 6 feet apart at the drums in a small club or at a club while going FOH?

I think i would gain volume on the other end of the stage for monitoring and possibly give the group more of a "full" sound.

I also know comb filtering will take place, but is this really a concern in real life applications for medium sized gigs?

what if the two cabs were slightly angled out?

other than loss of bass response due to decoupling, what real disadvantages are there to this method?

sorry for the hijack, but its still fairly on topic i think.
if the set-up was 300 watts into a total of 4 ohm load, would it be acting as two individual 150w rigs due to the separation or does it still act as a 300w rig with separated cabs?

thanks TB!
Click to expand...

I do that now and can't wait to see if I'm making a big mistake.:help:
 
#194
#195
JimmyM said:
Here I always thought the reason you could hear the bass in headphones was because of acoustic coupling with your head creating it. Headphones or earbuds always sound bassier when you mash them into your ear and less bassy when they're half on. So is that just a result of the passageway to your eardrums being less direct when they're half on?
Click to expand...
Good observation. I do think there is a lot more complex physics involved than most realize. For example, out in the free field, any wave's particle velocity and particle pressure will be 90 degrees out of phase (think of a string - where the anti-node's maximum displacement, and tensile stress, is at the point/time in which its velocity is minimum); whereas in the near field of a loudspeaker (for example, right next to the cone), the pressure and velocity are in phase. I wish my acoustics texts were not all boxed up, because it would be really interesting to write a paper on it. There is a lot more going on here than most audio guys realize. You really have to take courses in fluid mechanics and gas dynamics (conservation of mass, momentum, and energy) as well as differential equations (particularly Bessel functions) to begin to understand this stuff. It is VERY complex, and even engineers with advanced degrees have some difficulty with it. I often see a tremendous amount of oversimplification of things in these threads to make them grasp-able by lay persons, but the risk is that it's not really right (can sometimes be misleading). Take heart, though: this stuff is not easy to understand by any stretch. I majored in acoustics and I struggle with it.

- Mike
 
#197
MikeyD said:
Good observation. I do think there is a lot more complex physics involved than most realize.

- Mike
Click to expand...
In this case, it's far more simple than it may appear. First, SPL stands for Sound Pressure Level, pressure being the operative word. A sound source pressurizes the air in the vessel into which it radiates. In the case of headphones that vessel is your ear canal. Being so small in volume it's very easy for the headphone diaphraghm to pressurize it to a very high SPL. But if the seal between the phone and the ear isn't tight or the distance from the phones to the ear is increased then the diaphragm has to pressurize all the air external to the ear canal as well. It's like using a hand pump on a bicycle tire. A few strokes and you can reach 30 PSI. Try using that same pump to pressurize an entire house to 30 PSI.:bawl:
 
#199
I played a gig on Friday at a place where we set up in one end of the bar area facing the bar, but there is a dining room off to the side. People sitting in the dining area are 45° to 90° off axis. In the past I have had problems getting a well-defined sound in that area, setting up my two Eden 210XLTs horizontally.

So I thought it would be a good opportunity to get back into stacking the two Edens vertically, which I had not done in a while because of the reduced stability. So I took a relatively light head and stacked the cabs vertically.

I walked around the room before the first set to check the sound of the bass at different places in the room (I got a wireless unit just for this purpose). The sound was clear and even anywhere in the bar area as well as anywhere in the dining area.

There is nothing like walking around the room and listening!

So at least for this room I will continue to use vertical stacking.
 

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