Dispell for me please,...Power/Impedance/Volume/Tone Myths

[warwick.hoy]

I specifically bought a 4ohm cab so I could get more power from my amps under the impression that more power = more volume/better toanz. I definitely realize that I want to push more air too. I'm not opposed to multiple trips with lots of cabs for gigs.

Lately I've been reading up that more power doesn't necessarily mean more volume which is somewhat counter intuitive to me. I definitely feel like more power = better bass response.

For clarification:

Amps used = Yamaha PB-1-->Ampeg SVP 1500 (stereo poweramp). I use this rig with an Avatar B410 NEO (4ohms),...an ancient Ampeg 8x10 refridge cab (also 4ohms) from on channel of the poweramp and the other channel driving an 8ohm guitar cab.

Not sure of the wattage ratings (I think 925 @ 2ohms on one channel and ~300 @8ohms form the other) but it is a rig of doom. The 8x10 stays in the rehearsal studio since it's not mine. This is for the insanely and purposely loud noise band that I'm in. I need to add cabs that I can gig with in this context

I also use a Gallien Krueger MB2-500 into just the Avatar for the more straight forward rock band I'm in. 500 watts. In this case I want to start using 2 8ohm cabs so I can push more air,...and it would be nice to have a cab that is closer to ear level.

I'm looking to add cabs and the plan is to pick up a 2nd B410 NEO in 4ohms and two additional B410 NEOs in 8ohms. I could use all 4 cabs for the noise band and the 2x8ohm 410 cabs with the GK in the straight up rock band.

Feel free to point out any flaws in my logic.

[billfitzmaurice]

Originally Posted by warwick.hoy

Lately I've been reading up that more power doesn't necessarily mean more volume which is somewhat counter intuitive to me. I definitely feel like more power = better bass response.

It doesn't. First, most users assume that power and output are linear. They aren't. Twice the power only gets you 3dB additional output, whereas it takes ten times the power to sound twice as loud. Second, few speakers can take more than half their rated power before reaching maximum output. So if you have a 500 watt cab and a 250 watt amp chances are it's already going as loud as it can, and adding more power won't get you any louder. A larger amp will have more clean headroom, and that in itself is usually a good thing, but the vast majority of players who think that there's any benefit in running with a 4 ohm cab instead of an 8 ohm cab 'so I can get more watts out of my amp' are mistaken.

As for adding more cabs for more output, only half of what's gained is from the increase in power handling. The rest is the result of higher electrical to acoustical transfer efficiency when you add cabs.

[AwkwardLoudness]

All else being equal, more power allows more clean headroom, more bass response and, to a lesser extent, more volume unless the speakers have already reached their maximum dB level or maximum displacement. In general, adding additional cab(s) (of the same type already used) or using speakers/cabs that are more efficient are the best ways to increase volume....unless you mic or DI to a good PA system

Do I understand this correctly: You want to play through a quad of 4x10 cabs with two cabs driven by a GK MB2-500 and two cabs driven by a Ampeg SVP 1500? It's best to stack bass cabinets to allow for maximum dispersion, but it would be difficult stack four 4x10 cabs. There would be more sound wave interference with phase cancellations at some frequencies if cabs are side by side.

[warwick.hoy]

Originally Posted by AwkwardLoudness

All else being equal, more power allows more clean headroom, more bass response and, to a lesser extent, more volume unless the speakers have already reached their maximum dB level or maximum displacement. In general, adding additional cab(s) (of the same type already used) is the best way to increase volume....that or mic or DI to a PA system

Do I understand this correctly: You want to play through a quad of 4x10 cabs with two cabs driven by a GK MB2-500 and two cabs driven by a Ampeg SVP 1500? It's best to stack bass cabinets to allow for maximum dispersion, but it would be difficult stack four 4x10 cabs. There would be more sound wave interference with phase cancellations at some frequencies if cabs are side by side.

No the Ampeg is stereo with each channel capable of running down to 2ohms. I'd run what is essentially a 2ohm stack on one channel and a 4ohm stack on the other and have the cabs setup 2x2. The main reason for wanting the 2 8ohm cabs is so I can run them with the GK. A more traditional setup for a more traditional band.

The rig of doom is essentially for a really obnoxiously loud,...piss the bartender off noise band. We might catch flak for being so loud,...but I don't really care.

Talk to me a little more about phase cancellations and wave interference. The image I have in my mind about soundwaves emitted from speaker cabs is that of a flashlight beem. Are there ways to combat that?

[seamonkey]

Myths are Dispelled with Science

Take some measurements. Do a double blind test. etc.
http://en.wikipedia.org/wiki/Scientific_method

[billfitzmaurice]

Originally Posted by warwick.hoy

The image I have in my mind about soundwaves emitted from speaker cabs is that of a flashlight beem.

That's the single most common misconception in audio. Sound wave radiation bears no resemblance whatsoever to light waves.
Some of the basics are explained here:
http://www.jblpro.com/pub/manuals/pssdm_1.pdf

[AwkwardLoudness]

Originally Posted by warwick.hoy

Talk to me a little more about phase cancellations and wave interference. The image I have in my mind about soundwaves emitted from speaker cabs is that of a flashlight beem. Are there ways to combat that?

Higher frequencies are more focused and uni-directional than bass frequencies which disperse better in all directions. Guitarists have less to worry about when putting cabs side by side for this reason. The nodes in sound waves from two sources can cancel out in some locations, so two bass cabs side by side will sound uneven at best in certain areas of the room. You can use your cabs in a 2x2 formation, but there are better options. I play insanely loud sometimes like you seem to do, and I once had a rig with four Orange 1x15 cabs stacked vertically...loud, even, low, and good.

[warwick.hoy]

Originally Posted by billfitzmaurice

That's the single most common misconception in audio. Sound wave radiation bears no resemblance whatsoever to light waves.
Some of the basics are explained here:
http://www.jblpro.com/pub/manuals/pssdm_1.pdf

Just to clarify,...I was more referring to the "throw" of the cab as opposed to correlating sound waves with light waves. Obviously I have a lot to learn with regards to how sound travels, but I've always envisioned the sound coming from a speaker cab in the form of an invisible conical shape getting gradually wider as it travels away from the cab, not all that dissimilar to a beam of light emanating from a flash light..

Maybe give me the TL;DR version of the PDF you linked with regards to my comment.

[Rob Lewis]

What are "toanz"?

[warwick.hoy]

Originally Posted by Rob Lewis

What are "toanz"?

A meaningful and well thought out contribution.

If you can't figure it out on your own,...I'm not going to tell you.

[Rob Lewis]

Oh, I figured it out OK.
If you mean "tones", why not spell it properly?
In a metal band, are we?

[warwick.hoy]

Originally Posted by Rob Lewis

Oh, I figured it out OK.
If you mean "tones", why not spell it properly?
In a metal band, are we?

Some people might call it metal but it's more aggro improv free jazz jamband IMO with lots of feedback, fuzz,...some synths and samples mixed in. Like a pissed off Phish, but we really aren't trying to be pigeonholed.

It's an internet forum. I didn't realize I was obligated to spell things right,...I mean I caught I few spelling mistakes in my OP; possibly some grammatical errors, but the point seems to be conveyed clearly enough to me.

People have been purposely misspelling things on the interwebs for a while now. I'm not for the dropping of proper grammar,...but if the only thing you have to contribute to this discussion is grammar and stereotyping,...maybe head over to Harmony Central or TGP,...where relevancy has no place.

[billfitzmaurice]

Originally Posted by AwkwardLoudness

Higher frequencies are more focused and uni-directional than bass frequencies which disperse better in all directions. Guitarists have less to worry about when putting cabs side by side for this reason. .

They have more to worry about, as placing cabs, and for that matter drivers, side by side makes the situation worse, extending the zone of laser-beam dispersion further down the bandwidth.

[honestjohnny]

Originally Posted by warwick.hoy

Just to clarify,...I was more referring to the "throw" of the cab as opposed to correlating sound waves with light waves. Obviously I have a lot to learn with regards to how sound travels, but I've always envisioned the sound coming from a speaker cab in the form of an invisible conical shape getting gradually wider as it travels away from the cab, not all that dissimilar to a beam of light emanating from a flash light..

Maybe give me the TL;DR version of the PDF you linked with regards to my comment.

More like ripples on a pond. Air functions much like a fluid with regards to sound.

[Rob Lewis]

You're not obliged (or obligated-your expression-which sounds a bit like Dubya) to spell things "right" or correctly, but it always helps. Anyway, rock on, mon ami...

[warwick.hoy]

All irrelevant posts including my own have been reported,...thanks for playing. (not that anyone is paying any attention).

[Chef]

Mod Alert: We Are Paying Attention.

You don't have to spell correctly here, but it might help you communicate more clearly.
Pointing that out isn't infractable.
Pointing it out impolitely is.

So, y'all play nice.
There enough impoliteness both directions I'm not going to do anything here but some editing, but if y'all make me come back, it'll be different next time.

[seamonkey]

Originally Posted by honestjohnny

More like ripples on a pond. Air functions much like a fluid with regards to sound.

It's sound "pressure".
It's longitudinal pressure waves.
Sound is always drawn using waveforms, but that's just a visual representation. That's not how it travels in air.

Here's a good applet to show sound interference from two sources

http://www.falstad.com/interference/

[billfitzmaurice]

Originally Posted by seamonkey

It's sound "pressure".
It's longitudinal pressure waves.
Sound is always drawn using waveforms, but that's just a visual representation. That's not how it travels in air.

Here's a good applet to show sound interference from two sources

http://www.falstad.com/interference/

That applet only scratches the surface, as it shows the reaction of two sources at only one frequency at a time. To see how complicated things really are run that applet while sliding the frequency tool fully from left to right. Then imagine each of those individual results occurring simultaneously. And then imagine the effect of reflections off all the walls, ceiling and floor.

[warwick.hoy]

So going back to the two stacks side by side,...my motivation is seeing some of the bigger acts using two 8x10's side by side,...is it different with four 4x10's?

Avatar cabs are bottom ported and my plan was to stack the cabs on their sides and meet the ports in the middle/center.