More vs Less Cones - Impact on Tone, not Volume ?

[Wasnex]

I was actually thinking a bit about the acoustic coupling. Had a wild idea to fire one cab the other direction, but then fairly quickly realized that would probably result in a lot of ill effects (phase cancellation, etc) especially since the cabs are rear ported.

Try it, you might like it.

If you have two drivers playing the same tones in approximately the same plane there will be phasing and lobing. Exactly what happens depends upon the angle and spacing between the drivers, frequencies being produced, and the angle you are listening at. Stacking the cabinets vertically will decrease the perception of phasing at the cost of a narrower dispersion pattern and uneven frequency response in the vertical axis. In order to hear the full natural response of the speaker, the cabinet will either have to be at ear level, angled back to aim at your ears, or you will need to be a considerable distance in front of it.

Turning one speaker 90 to 180 degrees in the horizontal axis may actually improve the quality of the sound you hear by eliminating phasing issues in the midrange. Given the wavelength and omnidirectional characteristic of the frequencies that come from the ports and the size of modern speaker cabinets, flipping the polarity is not required for near perfect coupling across the sub 100 hz range. Near perfect coupling occurs when spacing between acoustic centers is less than approximately 1/4 wavelength. I would expect some low-mid lobing in the horizontal plane between the drivers.

 

[Doner Designs]

I have no idea. Why don't you hook it up and have the soundman and yourself judge for yourself?

I like to understand the theory and there are plenty of guys here who do know and have answered very well.

 

[Doner Designs]

God is there when he plays. God cares.

@DD you have the goodies, so why not go in early or stay late and give it a whirl?

Yep, and it's just one more trip to the (close) parking lot and one more cable. This is a satellite location to our main campus - meets in a middle school auditorium and the contract is restricted time-wise but there certainly is time to bring it in. It's probably worth bringing just to elevate the combo. I often sit it on a box of some kind but couldn't find anything last weekend so it was on the floor.

The rest of the instruments are DI only, so I have tried to hold back a little in terms of lugging in a lot of gear. I think the other bass players in the rotation use the crappy 1x15 combo owned by the church.

 

[Doner Designs]

I've got a personal experience relevant to your query, OP.

My band has a regular monthly gig at a real fun rock venue. It's a rowdy crowd and we pretty much let it rip. I've played that venue many times with my usual rig, a Mesa D800 pushing an Arnopol MAS112 cab--and it's loud enough and sounds good.

I happen to have two of those MAS112 cabs, so just for the heck of it I brought both cabs one night. Def, the bottom seemed to punch more. It wasn't simply a gain in volume; I had the master down from where I set it with one cab, and our stage volume is pretty consistent night to night. So now I set both of them up, side by side.

Side by side....so what you heard evidently was not related to getting it up off the floor. I assume that part of the difference in what you hear stacked has to do with the elevation especially when not using tilt back cabs.

 

[NaH]

Did you notice a difference between elevated and on the floor? At a past church I tried both a Markbass Traveller 102p and a vertically stacked CMD 121p w/NY121. Even though it was very close, in that case I preferred the 2x10 cab and I preferred it in the vertical position (at least on that stage). Weight wise (head + cab) it is less.

Right now at my current church I am just using the CMD121p on the floor on the stage (which is just a couple steps up). I've been told they can feel the vibrations when they touch the pews.

 

[Pat C.]

IMO, more comes always better. As others have said, low end coupling provides more even response, even at the same SPL.

 

[JimmyM]

It's the matching cab - so the tone will be the same as your combo. Don't worry about it.

Please also realize that your audience doesn't care or appreciate your tone - as long as they can hear you thumping it's fine as far as they are concerned. It took me a long time to realize this. Only us players care about the tone.

Bless you for this. Getting this overlooked fact out there has, apparently, become my life's work.
The drunk in the back of the room staring at the fat girl's tight jeans could not care any less what your bass tone is.

Using the drunk in the back of the room as your gauge means that you will spend your life playing to drunks in the back of the room. Why not just use a First Act starter kit with a little 5w amp if it doesn't matter? Why even show up if that's how you feel? I find it a position based on arrogance.

You know, a lot of people who come to shows also play music, and they might not be the world's greatest but they do know good tone and good playing when they hear it. I am constantly surprised by how many people come up to me at my shows and comment on the sound, both good and bad. But let's say that the vast majority of people at your gig have no idea about sound...some do, and some of those people might be in a position to help you one day. I've gotten pretty good gigs simply because someone looking for players was in the audience and they liked what they heard. Word of mouth is everything in the music business, and I choose to present myself as someone who cares about what I'm doing and I put my best foot forward as much as I can. It's served me pretty darn well, and while I'm not rich and famous, I do a lot of fairly serious gigs and make a good bit more than most musicians that I know. If I used the drunk at the back of the bar as my goalpost, no doubt in my mind that I'd still be playing to them.

 

[Gizmot]

Assuming you're adding identical drivers, there will be a tonal affect because the acoustic coupling of the drivers is better at lower frequencies, so you'd typically get more bottom end at the same amp settings when you add a cab. Acoustic coupling is most effective at frequencies with wavelengths longer than twice the distance between driver centres and it drops off at shorter wavelengths. So with a pair of 12s you'd get good acoustic coupling below about 560Hz and it would roll off above that giving you a low end boost.

Beautifully stated response - and its correct. Don't forget that at upper mid and high frquencies you'll get some comb filtering (destructive interference) based on enclosure spacing, HF dispersion, etc. Comb filtering is bad for pure audio but in some cases can actually make bass sound better

 

[ofajen]

Correct, sir. Only the Sound Providers./QUOTE]

Is that a band? If not, it should be.

Otto

 

[walterw]

Side by side....so what you heard evidently was not related to getting it up off the floor.

stack 'em, it'll be better all the way around. in fact, if the cabs aren't square, stack 'em tallways, it'll be better still.

Using the drunk in the back of the room as your gauge means that you will spend your life playing to drunks in the back of the room.

sig-worthy!

 

[BAG]

Yep...... the more cones your crowd has smoked the more they appreciate your tone....... man........

 

[chris_b]

If more volume is required I'd always add a second cab before I turned the volume all the way up.

A second cab will get you heard and it'll also make you sound good. Moving air is what creates sound or tone. Moving more air creates more tone. If you've got a good amp and can use the EQ, more tone should be better tone.

Headroom is good in amps and cabs. If any part of your rig is working too hard it's probably moving into an area where it won't be sounding so good.

A second 112 is a no brainer.

 

[Mark Reccord]

Oh No! You did not just mention the type of wood in your bass........!
(I'm a believer.)

I think he meant the type of wood in your bass's knobs...

I was actually thinking a bit about the acoustic coupling. Had a wild idea to fire one cab the other direction, but then fairly quickly realized that would probably result in a lot of ill effects (phase cancellation, etc) especially since the cabs are rear ported.

That will certainly change the way the cabinets couple acoustically because the distance between the drivers will change and they will no longer be coplanar. This will have the most affect at midrange and higher frequencies and won't affect the true low end very much at all. You'll still get good coupling at frequencies below ~150Hz because the wavelengths are long enough (compared to the size of the drivers and the distances between them) that they are not directional and the differences in phase are not significant. The placement of the ports would actually be the least of the potential issues with this.

Beautifully stated response - and its correct. Don't forget that at upper mid and high frquencies you'll get some comb filtering (destructive interference) based on enclosure spacing, HF dispersion, etc. Comb filtering is bad for pure audio but in some cases can actually make bass sound better

Thanks. I'm glad I was able to get the idea across in a way that makes sense. And yes, exactly. Once you get above the coupling frequency limit things can get pretty ugly in terms of pure audio behaviour, but the result isn't necessarily bad unless you're a stickler for "technically correct." I use a 610 cab with no tweeter and on paper the response above about 600Hz starts to fall apart, yet it sounds freakin' great to me with my bass. I wouldn't want to depend on it for music playback, though.

 

[Doner Designs]

If more volume is required I'd always add a second cab before I turned the volume all the way up.

A second cab will get you heard and it'll also make you sound good. Moving air is what creates sound or tone. Moving more air creates more tone. If you've got a good amp and can use the EQ, more tone should be better tone.

Headroom is good in amps and cabs. If any part of your rig is working too hard it's probably moving into an area where it won't be sounding so good.

A second 112 is a no brainer.

I suppose the same idea would apply if I'm already loud enough - adding a cab would allow for turning the amp down. Not only would it add headroom to the amp but if each cone is moving less it seems like there would be more cone excursion on reserve for punchier transients. I don't know much about driver construction, but it seems like they would have to get "tighter" at the limits of excursion to be safe from accidental damage (like when you accidentally unplug before turning down/off).

 

[Doner Designs]

Did you notice a difference between elevated and on the floor? At a past church I tried both a Markbass Traveller 102p and a vertically stacked CMD 121p w/NY121. Even though it was very close, in that case I preferred the 2x10 cab and I preferred it in the vertical position (at least on that stage). Weight wise (head + cab) it is less.

Right now at my current church I am just using the CMD121p on the floor on the stage (which is just a couple steps up). I've been told they can feel the vibrations when they touch the pews.

Mostly I hear myself better when the cab is elevated since it's not a tilt-back. As for nuances, I'm not the greatest player (90% gear-geek 10% part talent) so my mind is 99% focused on not screwing up. The rest of the crew are basically professionals, so I'm busting my butt to keep up.

 

[Doner Designs]

I think he meant the type of wood in your bass's knobs...

I have heard that wood knobs are good for metal.

 

[BadExample]

I have heard that wood knobs are good for metal.

Makes sense. Dissimilar materiais are used in things like solid bearings.

 

[chris_b]

I suppose the same idea would apply if I'm already loud enough - adding a cab would allow for turning the amp down. Not only would it add headroom to the amp but if each cone is moving less it seems like there would be more cone excursion on reserve for punchier transients.

Steve, that all seems very logical to me. IME adding the extra cab brings more "quality" to the sound, an improvement that is greater than the sum of the parts. I haven't found a down side to adding an extension cab.

 

[ofajen]

I was actually thinking a bit about the acoustic coupling. Had a wild idea to fire one cab the other direction, but then fairly quickly realized that would probably result in a lot of ill effects (phase cancellation, etc) especially since the cabs are rear ported.

I wouldn't really be inclined to try that at a gig, but I've played bass thru an open-back guitar cab at modest levels in my studio and it sounded delicious. The openness and spaciousness was cool. I'd think similar, stacked cabs with one pointed backwards might produce a similar effect.

Otto

 

[HaphAsSard]

Another thingie I think and hope I've grasped from these forums is baffle step: having two stacked cabs instead of one lowers the point (or area) of the response below which frequencies are omnidirectional, and above which a 6dB peak, for the same reason (frequencies whose wavelengths are now too short to get around the baffle are projected in half the space), is produced. While the general area is still that of low mids, the downward shift in the step due to stacking (and a wider total baffle) approaches that of the upper bass (depending on the dimensions and shape of the cabs involved) and thickens the sound.
Or sumthin.