Stacking Question

[Wayward-Wanderer]

Anyway, Why is it that bass stack are 90% of the time the 1x15 is on the bottom and 2x10, 4x10 is on top? Is it a question of sound quality?
I heard somewhere around here that turning 2x10 on there side makes them produces better sound. Is that true for other cabs?

Edited July 26, 2008 by Wayward-Wanderer

[alexclaber]

The dispersion of a source is inversely proportional to its size and the frequency it is producing. So a horizontal 2x10" has worse left-to-right dispersion than a vertical 2x10".

If you have one cab with 10" speakers and one with 15" speakers, generally you want to hear the mids and highs from the 10" cab. By lifting that cab closer to ear level you improve the audibility of those frequencies.

Alex

[bass_ferret]

Your'e a glutton for punishment

The fallacy that the "bass" cab goes on the bottom and the "treble" cab goes on the top when they are both reproducing the same signal (unless they are actually being bi-amped) is an extension of the fallacy that a stack has to have 15's and 10's. Because old skool PA's (lots of modern PA's are multiple arrays of full range cabs rather than the old stack of bass bins, mids and tweeters approach) and most hifi speakers (not mine I hasten to add) have the woofers at the bottom and the tweeters at the top would be my guess.

The cabs on their side bit arranges the drivers vertically. This is because of another bit of science that may or not affect the sound (in your opinion) etc etc. Horizontal arrangement of drivers causes something called comb filtering or lobe filtering, where phase cancellation causes peaks and troughs in SPL depending on your position relative to the cabs. Edited July 26, 2008 by bass_ferret

[Bill Fitzmaurice]

[quote name='bass_ferret' post='248346' date='Jul 26 2008, 06:55 AM'] Your'e a glutton for punishment

The fallacy that the "bass" cab goes on the bottom and the "treble" cab goes on the top when they are both reproducing the same signal (unless they are actually being bi-amped) is an extension of the fallacy that a stack has to have 15's and 10's.[/quote]
It's not a matter of both reproducing the same signal, it's a matter of dispersion. Even if the 15s and 10s have exactly the same frequency response chances are the tens will have wider dispersion in the midrange, so better to have them on top where that dispersion can be put to good use.

[quote]The cabs on their side bit arranges the drivers vertically. This is because of another bit of science that may or not affect the sound (in your opinion) etc etc. Horizontal arrangement of drivers causes something called comb filtering or lobe filtering, where phase cancellation causes peaks and troughs in SPL depending on your position relative to the cabs.[/quote]The existence of comb-filtering isn't a matter for debate, it's a phenomena well known for at least 75 years. Those who deny its effect should also consider memberships in the Flat Earth Society.
OTOH elimination of combing is not the overriding reason for vertically aligning drivers. Expanding the width of the horizontal plane of dispersion, as Alex explains above, is. Second to that is the narrowing of the vertical dispersion pattern, placing more sound in the audience, unless you're playing to dust mites on the floor and bats in the belfry. As a benefit of vertical alignment the elimination of combing comes in third.

Edited July 26, 2008 by Bill Fitzmaurice

[bass_ferret]

But is wide dispersion always desirable? Yes if the rig is FOH as well, but probably not where the PA is FOH, the stack is for stage only and would be better beamed at the bass player rather than dispersed and bleeding into all the vocal mic's?

[Dubs]

Oh sh*t, I’ve just had a massive déjà vou moment. Not this old debate again…are there not about 10 threads on this already?

[alexclaber]

[quote name='bass_ferret' post='248504' date='Jul 26 2008, 05:03 PM']But is wide dispersion always desirable? Yes if the rig is FOH as well, but probably not where the PA is FOH, the stack is for stage only and would be better beamed at the bass player rather than dispersed and bleeding into all the vocal mic's?[/quote]

In my band my fellow bandmates like to be able to hear what I'm playing.

Alex

[warwickhunt]

BassChat wouldn't be BassChat without this perennial favourite

[Bill Fitzmaurice]

[quote name='bass_ferret' post='248504' date='Jul 26 2008, 12:03 PM']But is wide dispersion always desirable?[/quote]Dispersion is not a constant, it varies with frequency. No matter how a cab is oriented low frequency dispersion (roughly 400 Hz and below) is 360 degrees. Going higher in frequency the dispersion angle narrows as frequency goes up, so the cab sounds different depending where you're standing. The wider the dispersion angle is maintained with increasing frequency the more uniform it sounds within the listening area.

[bass_ferret]

[quote name='benwhiteuk' post='248516' date='Jul 26 2008, 05:15 PM']Oh sh*t, I’ve just had a massive déjà vou moment. Not this old debate again…are there not about 10 threads on this already?[/quote]
just playing devils advocate

[Dubs]

[quote name='bass_ferret' post='248578' date='Jul 26 2008, 07:02 PM']
just playing devils advocate [/quote]

as always

I'd give my 2 pence worth on this if I hadn't already given about a quid fifty's worth to some other threads that are very similar to this one. I’m not getting involved in enclosure design or comb filtering debates again, despite how fun they may be

[bennifer]

Who gives a sh*t? It looks cooler with the bigger driver on the bottom of the stack, and thats all that matters!

[bass_ferret]

[quote name='bennifer' post='248643' date='Jul 26 2008, 09:11 PM']Who gives a sh*t? It looks cooler with the bigger driver on the bottom of the stack, and thats all that matters![/quote]
[quote name='bass_ferret' post='246832' date='Jul 24 2008, 01:25 PM']At the risk of being controversial the stack is as much about image as sound.[/quote]

[waynepunkdude]

I played with a band a few weeks back, the bass player had the same cab as me (Ashdown 4x10) so we decided instead of stacking them we set one up on each side of the stage and it sounded amazing, not much help but I'm never much help.

Edited July 27, 2008 by waynepunkdude

[Bill Fitzmaurice]

[quote name='waynepunkdude' post='248875' date='Jul 27 2008, 07:50 AM']I played with a band a few weeks back, the bass player had the same cab as me (Ashdown 4x10) so we decided instead of stacking them we set one up on each side of the stage and it sounded amazing, not much help but I'm never much help.[/quote]
There probably were some places where it sounded amazing, but they would have been exceeded by those where it sounded worse than if stacked. A visual representation of why using spread low frequency sources is a bad idea found here:
[url="http://www.falstad.com/wavebox/"]http://www.falstad.com/wavebox/[/url]

BTW, the same destructive interference that occurs at low frequencies with cabs placed more than a few feet apart occurs in the mids and highs when drivers within a cab are horizontally mounted.