What's the deal with Cab size combinations?

[billfitzmaurice]

What about cabs that are advertised by the manufacturer to work well together, but aren't exact matches? I see a lot of folks on the Eden forums talking about how nice the 410XST works with the 410XLT.

That's easy enough, have them show you an SPL response chart of each cab, a pair of both and then the mixed pair. Phase problems and other anomalies will be as plain as the nose on your face.

Oh look, I see a flock of pigs flying overhead!

It still comes down to trying the three possible combinations of two of those cabs. Anyone who hasn't actually done so has no basis for comparison.

 

[gnjpowell]

"but 10" speakers don't reproduce bass frequecies at all" If that's at all true, why has [and is] the Ampeg 8x10 cab been the Gold Standard for ~40 years?

 

[gnjpowell]

Unpredictable impedance anomalies will result when combining non-identical drivers or speakers powered directly [no crossovers] by the same amplifier. This may be what is causing the perception of "holes" in the sound described by others. The Yamaha PB1 bass pre-amp has a very nice and fully adjustable built-in crossover to drive sep amps [bi-amping] to address this very issue as well as other issues. This is one technically correct way to use different speakers & cabs and get EXCELLENT sound.

 

[dhsierra1]

A 30" circle does not have the same area as two 15" circles.

The formula for area of a circle is pi*radius*radius.
radius of a 30" circle is 15"
radius of a 15" circle is 7.5"
pi is about 3.14
so,
area of 30" circle =~ 3.14 * 15 * 15 = 706.50"
area of two 15" circles =~ 2 * (3.14*7.5*7.5) = 353.25"

so the 30" circle has twice the are of BOTH 15" circles.
Another way to say it is that the 30" circle has four times the area of of a 15" circle.

The reason you don't get double the area with double the radius is because area is a 2-dimensional quantity and radius is 1-dimensional. The 2-d quantity has something squared in it (radius*radius).

However,
Notice I said "circles", not "speakers". Speaker cones are cone-shaped. There are equations for the area of conic sections (which I would have to look up and probably aren't necessary here) but the same principle applies. When you double the diameter you get four times the surface area.

As for why they had to use superlight materials for the EV 30" cone, consider that they had to push the mass of the cone. Mass relates to volume, a 3-dimensional measurement. The volume of the cone (area * thickness) would go up with something cubed. So, doubling the radius would raise the mass by something like eightfold (two to the third power = 8).

you obviously missed my ""

I don't have to worry about anemia as I have a lifestyle rich in irony

 

[dhsierra1]

The 'compressed foam' in question resembled the foam used in disposable coffee cups. They used it because the mass of a traditional cone was so high that the driver motor couldn't power it.

geez, that's the biggest disposable coffee cup I've ever heard!

 

[dhsierra1]

I like the bass dhsierra1 suggested to be played through it... this thread made my morning.

think of the weight, though, if they used either carved or plywood

Maybe they used the same compressed foam as the EV 30" driver......

 

[makohund]

I proved the theory to myself by simply comparing a mixed cab rig to a rig with two identical cabs and the difference was staggering.

The point that Bill and Jimmy were making I think is that if you have a mixed rig and nothing else to compare it to, you may be totally satisfied with it and not need to look any further. But that doesn't change the fact that a pair of matching cabs will almost certainly sound fuller, louder and more even when listened to in comparison.

++1

I ran a 2x10+15 for many years. Same manufacturer, supposedly matched well. Liked it. Thought it sounded good. Others always told me it sounded great. Other players would sometimes talk of wanting to put together something similar, liking what they heard of mine.

The main reasons I was interested in a new cab... a little more volume and a little less size. That's it. Wasn't searching for tone improvement, and any achieved would just be gravy.

Had a fEARful built and A/B'd the two... holy crap. The difference was astounding. And it wasn't just pure fEARful bad-assitude... I could totally hear what everyone describes here with the cab mixing, and had never noticed much or been able to put a finger on before. It was an enlightening, "what the hell have I been doing for all of these years" moment.

Even though it did sound good, and I liked it... not doing it was a revelation, and simply sounded that much better. I'd totally sell one or the other to get a matched set instead, if I didn't already have the new cab.

 

[billfitzmaurice]

++1

I ran a 2x10+15 for many years. Same manufacturer, supposedly matched well. Liked it. Thought it sounded good. Others always told me it sounded great. Other players would sometimes talk of wanting to put together something similar, liking what they heard of mine.

The main reasons I was interested in a new cab... a little more volume and a little less size. That's it. Wasn't searching for tone improvement, and any achieved would just be gravy.

Had a fEARful built and A/B'd the two... holy crap. The difference was astounding. And it wasn't just pure fEARful bad-assitude... I could totally hear what everyone describes here with the cab mixing, and had never noticed much or been able to put a finger on before. It was an enlightening, "what the hell have I been doing for all of these years" moment.

Even though it did sound good, and I liked it... not doing it was a revelation, and simply sounded that much better. I'd totally sell one or the other to get a matched set instead, if I didn't already have the new cab.

It's pretty much the same as comparing cars was when I was a kid. Everyone raved Chevy this, Dodge that, Ford (fix or repair daily?) Pontiac, etc. ad infinitum ad nauseum. And like everyone else I fell for the Detroit Iron hype of the '60s. And then I drove my first BMW.

 

[mattpnolan]

Over the last couple days, I've been reading several of the threads on this topic, and a lot of it makes sense to me.

However, I have one question that I haven't been able to get a good answer on (from what I've read).

Does this issue apply to single cabs with different size drivers in them, such as a Schroeder 310212?

I used to own a 310212 that I loved. However, I got rid of it after leaving a band and now only play with two 15" Bag End cabs which I also love, though it's a different sound (fits my current needs better).

Thanks!

 

[Rob22315]

Hey, if anyone wants to give me a 410TVX or a 115BX BW, I'll give it another try!!

 

[steve_rolfeca]

If they have similar phase relationships, they can work well together. Greenboy, who invented the fEarful 3 way cabs, says that his 15/6 works well with his 12/6 because they have similar phase relationships.

Perfect example. While just about any pair of decent cabs will sound OK when stacked, if you want really exceptional performance, you have to sweat the details.

In the case of Greenboy's cabs, the boxes are carefully designed to be complimentary, even to the point that the second cab is given a reversed baffle when used for stacking- so that the mid and HF drivers line up for optimal dispersion. Testing has proved that the placement for the smoothest and best response comes down to fractions, not inches.

This is the way really great, not just good, speaker systems are designed, whether we're talking about a bass rig, a concert sound system, or home audio. For anyone who's had the privilege of auditioning a really first-rate setup, it's well worth the extra effort.

 

[Windreaper]

Does this issue apply to single cabs with different size drivers in them, such as a Schroeder 310212?

Yes, if all the drivers are reproducing the same frequency range. Usually this isn't the case and there is a proper crossover (take a look at greenboy's fEarful thread for a good example).

Dunno about that Schroeder, though. Is it a 2-tie or 3-tie cab?

EDIT: Uh, did some digging myself. Looks like it's a 2-tie cab and a funny one at that. Definitely a culprit.

http://www.talkbass.com/forum/f15/my-schoreder-310212-wimp-out-718629/index2.html#post10097921

 

[billfitzmaurice]

Does this issue apply to single cabs with different size drivers in them, such as a Schroeder 310212?
!

It does. There is no engineering justification for using different driver sizes to cover the same bandwidth. There is a marketing reason for doing so, namely that anything which some people will pay for someone else will sell.

Usually this isn't the case and there is a proper crossover

If only, but where electric bass is concerned the one component that does allow using different driver sizes together, a good crossover, is the one component most often not used.

 

[Windreaper]

I was kind of thinking of PA speakers as I can't think of too many commercial bass cabs with odd driver mixes besides some Schroeder cabs, Peavey 1820, Trace Elliot 1015H, Mesa Powerhouse 1000/1200 and I believe Ampeg had a 4x10/1x15 model too, iirc. SWR kind of went half the distance with the Triad (used a 10" mid, meh).

But you're right, as far as I know, cab makers often skip even 2-tie xovers and just highpass the tweeter. And when they bother including a proper xover...kind of digressing here, but I'm using a GK biamp rig and I can't help wondering why they did not make the crossover frequency adjustable (after going through the trouble of putting an electronic xover into their bass amps...). The P-Audio hf driver is flat down to 1,5k so crossing over at 3k shouldn't be a problem...

 

[makohund]

The Peavey 1820 had a crossover in it. Also had separate inputs for bi-amping. Paired up pretty good with a Megabass. (An old rig of mine.)

 

[bassguitarthund]

A 30" circle does not have the same area as two 15" circles.

The formula for area of a circle is pi*radius*radius.
radius of a 30" circle is 15"
radius of a 15" circle is 7.5"
pi is about 3.14
so,
area of 30" circle =~ 3.14 * 15 * 15 = 706.50"
area of two 15" circles =~ 2 * (3.14*7.5*7.5) = 353.25"

so the 30" circle has twice the are of BOTH 15" circles.
Another way to say it is that the 30" circle has four times the area of of a 15" circle.

The reason you don't get double the area with double the radius is because area is a 2-dimensional quantity and radius is 1-dimensional. The 2-d quantity has something squared in it (radius*radius).

However,
Notice I said "circles", not "speakers". Speaker cones are cone-shaped. There are equations for the area of conic sections (which I would have to look up and probably aren't necessary here) but the same principle applies. When you double the diameter you get four times the surface area.

As for why they had to use superlight materials for the EV 30" cone, consider that they had to push the mass of the cone. Mass relates to volume, a 3-dimensional measurement. The volume of the cone (area * thickness) would go up with something cubed. So, doubling the radius would raise the mass by something like eightfold (two to the third power = 8).

Uhhhhhhhhhh................ I will take your word for it, lol!!!

 

[OOZMAN]

1x18 is ideal. It rolls off every thing you don't want and kicks ass with what you do. 1x15 is OK, but 10" speakers don't reproduce bass frequecies at all......

This guy knows what hes talkin' bout!

fun to find stuff on Google Image, I must say

But think of it, just one of these 30" monsters and that's exactly the same as a 2-15........

A 30" circle does not have the same area as two 15" circles.

The formula for area of a circle is pi*radius*radius.
radius of a 30" circle is 15"
radius of a 15" circle is 7.5"
pi is about 3.14
so,
area of 30" circle =~ 3.14 * 15 * 15 = 706.50"
area of two 15" circles =~ 2 * (3.14*7.5*7.5) = 353.25"

so the 30" circle has twice the are of BOTH 15" circles.
Another way to say it is that the 30" circle has four times the area of of a 15" circle.

The reason you don't get double the area with double the radius is because area is a 2-dimensional quantity and radius is 1-dimensional. The 2-d quantity has something squared in it (radius*radius).

However,
Notice I said "circles", not "speakers". Speaker cones are cone-shaped. There are equations for the area of conic sections (which I would have to look up and probably aren't necessary here) but the same principle applies. When you double the diameter you get four times the surface area.

As for why they had to use superlight materials for the EV 30" cone, consider that they had to push the mass of the cone. Mass relates to volume, a 3-dimensional measurement. The volume of the cone (area * thickness) would go up with something cubed. So, doubling the radius would raise the mass by something like eightfold (two to the third power = 8).

Beat me to it

 

[dhsierra1]

This guy knows what hes talkin' bout!





Beat me to it

again, my ironic sense of humor flies overhead like so many seagulls, I'll have to stop using the smileys and instead use neon fonts indicating that I'm kidding.

:scowl:

 

[TheRealKong]

Hmmm, bass-frequencies are not about the size/radius of the drivers. It's about the frequency the driver goes for-and backwards.

Lets say, "C' " has 264 hz, means movements (vibrations? Don't know the real expression, I am not native english or american...) per second. Tha "A' " has a frequence of 440 hz, means 440 moves / sec. The deeper the tone, the shorter the frequenz, the less movements per second.

The Problem with big drivers - they dont swing proper. This is the case why the cone is in its shape - and Hartke works with aluminium cones. A cone is much mor stout than a plain paper circle, can you imagine?

Imagine a driver in plain round. It would swing quite uncontrolable. The cone shape makes it more stable. But in a moment the size is too big and the driver movement can't be controled propperly.

This makes the 10'' - Speakers so usefull: With 4 x 10 in a cab you have nearly the same inch² as in a 2x15'' - cab. A 1x15 has 176,63 square inch, two of them 353,25 square inch. A single 10'' - Speaker has 78,5 square inch, 4 of em will equal 314 squre inch.

Thats 355 square inch for 2x15 to 314 square inch for the 4x10. The four speakers will accelerate much faster, better response, damping is easier, so the tone is more acurate, clearer, punchier.

I mix up all cabs I have: A SWR 212 Workingpro with a Peavey TVX 210, a Peavey TVX 210 with a TVX 410, the cab fixed wih my Marshall MB 4410 with a more than 30 years old Ampeg 410 - cab (no tweeter), my SWR Redhead with that Ampeg - cab. And it all works! Fine tone, loud, punchy, as I always wanted.

My main setup is an Ampeg SVP-Pro Preamp with a german poweramp, the Ampeg 410 with the SWR 212. No interferrences, I measured them, all the same phase, it all sounds real good together. With my main setup I am often asked about my rig because of the fabulous tone.

30 years ago I had a 2x15 - cab - and I couldn't get a good tone out of it. Maybe the poor amp I used this time was too weak to move this two huge EVM 15 B. After that I had a Marshall 18'' - cab, a huge thing.I traded it to a tech who has already one and who built a three-way-cab, using it as a small PA this times. The PA-thing worked, but I couldn't cut through in the mix with both of them cabs. It was awfull.

So I was that happy when trading the 118-cab with that Ampeg 410-cab. From this verry moment I had my sound.

 

[adivin]

Check out the Victor Wooten article in BPM. He uses Hartke 410 and 115 together. Someone needs to tell him he's got it all wrong.