rank loudness of common cab/driver configs - Page 3

Tuned · #41 11-19-2012, 04:56 PM

Quote:

Originally Posted by Downunderwonder

Cone diameter is well short of nominal. Use the published cone area x xmax if there isn't a Vd.

Xmax is part of "all things being equal", like I said, they're actually not. In reality you have to figure Vd and BL, the motor force behind the cone.

Let's borrow Eminence's stock ratings:

Both the 10" Basslite CH2010 and 15" C2515 have an 11.1 BL product, which is typical between bass speakers of different sizes from the same company. The CH2010 has an Xmax of 7.5mm for a 120cc Vd and the C2515 Xmax is 8.5mm for a 381cc Vd, again typical.

So here's how it plays out:
4x10 = 44.4 BL x 480cc Vd = 21312
2x15 = 22.2 BL x 762cc Vd = 16916

So all things really being equal, a 4x10 has 26% more "output capacity" than a 2x15. Can we get past this already? There's no such thing as a magic 2x15 that blows away 4x10's because the exact same advances in the 15's can and will be applied to the 10's made by the same company. 4x10 is just a better configuration. Deal with it.

scottfeldstein · #42 11-19-2012, 05:01 PM

And heeeeear we go.

Seriously, though, guys. I can't just "get an 810 and be done with it." I need a cab that an old guy can carry safely. Like 50 pounds is the absolute limit.

Tuned · #43 11-19-2012, 05:05 PM

And while we're at it:

4x12 = 44.4 BL x 540cc Vd = 24976 (S2012's)
^ only 12.5% more output capacity than 4x10

However:
6x10 = 66.6 BL x 720cc Vd = 47952
^ almost twice the output capacity of a 4x12

Face it, 10's are your daddies.

Tuned · #44 11-19-2012, 05:09 PM

SWR Golight 4x10 = 56 lbs, probably lightest 4x10 out there with good drivers. A 2x10 may serve your purposes though, beats a 1x15 by the same 26%.

scottfeldstein · #45 11-19-2012, 05:18 PM

No more 410s! I can't take it, 56 lbs or not. My 212 is 50.5 lbs and it's already at the limit, really, of what I should be carrying around with this back. All I need is to go to a gig and seriously injure myself before showtime.

A quality 15 might be ok atop my 212; if it's in distress, I would hear it because it's nearer my ears. Heck I know respectable TBers who like a single 12 atop their 212!

A 210 would be even closer in output, though I would put it on top as well for the same reasons.

I think it's really looking like a cheap 210. If I had to buy today, I'd grab a used Peavey or GK 210 for $150 or less.

dhsierra1 · #46 11-19-2012, 05:24 PM

BL, ie motor strength is going to be resisted by a number of factors including stiffness of the surround, spider, and cone. Just because there is a higher BL in a particular driver doesn't automatically make that the more powerful driver in terms of actual output as measured by displacement. This is partly why you also have to take into consideration the efficiency of the driver at the bandwidth of interest because of all the resistive forces in the speaker in toto: electrical as well as mechanical.

IME I've not heard a 4-10 go as loud w/o breaking up as a 2-15, nor a 2-10 against a 1-15.

scottfeldstein · #47 11-19-2012, 05:31 PM

Quote:

Originally Posted by dhsierra1

IME I've not heard a 4-10 go as loud w/o breaking up as a 2-15, nor a 2-10 against a 1-15.

Really. This is getting interesting. Anyone disagree with this?

Downunderwonder · #48 11-19-2012, 06:12 PM

You just did like I said and used Vd in place of nominal cone area, show me a driver that can't push xmax, puleaze, that's a given, as equal as it gets.

Quote:

Originally Posted by Tuned

Xmax is part of "all things being equal", like I said, they're actually not. In reality you have to figure Vd and BL, the motor force behind the cone.

Let's borrow Eminence's stock ratings:

Both the 10" Basslite CH2010 and 15" C2515 have an 11.1 BL product, which is typical between bass speakers of different sizes from the same company. The CH2010 has an Xmax of 7.5mm for a 120cc Vd and the C2515 Xmax is 8.5mm for a 381cc Vd, again typical.

So here's how it plays out:
4x10 = 44.4 BL x 480cc Vd = 21312
2x15 = 22.2 BL x 762cc Vd = 16916

So all things really being equal, a 4x10 has 26% more "output capacity" than a 2x15. Can we get past this already? There's no such thing as a magic 2x15 that blows away 4x10's because the exact same advances in the 15's can and will be applied to the 10's made by the same company. 4x10 is just a better configuration. Deal with it.

dhsierra1 · #49 11-19-2012, 06:19 PM

Quote:

Originally Posted by Downunderwonder

You just did like I said and used Vd in place of nominal cone area, show me a driver that can't push xmax, puleaze, that's a given, as equal as it gets.

yup, the results (ie output over the targeted bandwidth) are what you're looking to measure in this particular conversation, not so much how it gets there unless you're designing the driver, a different discussion.

RockDoc · #50 11-19-2012, 06:21 PM

"However:
6x10 = 66.6 BL x 720cc Vd = 47952
^ almost twice the output capacity of a 4x12"

Forgive me if I'm overlooking something, and understand that math isn't my forte, but if the quotation above is accurate, then couldn't we divide that by two and get: 3x10 = almost the output capacity of a 4x12? That somehow doesn't seem right....

And Scott, just hang and save for a while, and get a second GK NEO 212!

Downunderwonder · #51 11-19-2012, 06:30 PM

Ignore BL, it is part of the big picture, like air density at altitude.

scottfeldstein · #52 11-19-2012, 07:45 PM

Quote:

Originally Posted by RockDoc

Scott, just hang and save for a while, and get a second GK NEO 212!

That may be exactly what I end up doing. I have no pressing need for a second cab at the moment. All we're doing is recording. I haven't seen a stage in ages, and won't until the album's released in spring.

fdeck · #53 11-19-2012, 07:52 PM

The problem with focusing on any particular parameter, such as BL, is that all of the parameters are intertwined with one another in the equation which governs sensitivity at low frequencies. For instance, BL is the motor strength, but BL also figures into electromagnetic damping, which is a frequency dependent opposing force.

musicman666 · #54 11-19-2012, 08:04 PM

No matter what you guys say my (2) GK Neo 115's are plenty loud for me nowadays. In the past an 810 or (2) 4x10's was the only way to fly.....unfortunately my ears have paid the price, even with ear plugs....

I still think a 115 is louder than a 2x10....lol

Mr. Foxen · #55 11-19-2012, 08:06 PM

Other non equal thing is dispersion. Smaller is better for that, and its one place the 2x15 wins out because typically the configuration of a 2x15 is right for optimal dispersion with that cone size, whereas most other multi driver cabs aren't.

musicman666 · #56 11-19-2012, 08:09 PM

^^ Who can argue with that!

Interceptor · #57 11-19-2012, 09:16 PM

Oh boy.

There are so many variables it can spin your head off. The bottom line is that generalizations are dependent on driver performance being similar across a family line, and the box tuning also being the same. If (and that's huge if) that's the case, your chart is close enough.

But. Ain't nothing the same, and any designer worth the salt in his spit optimizes designs in pursuit of either a singular goal or finding a happy medium. Then there is the economics thing.

What I've learned the hard way is that the best way to pick a cabinet is to figure out what the problem is that you want to eliminate once and for all. Find a cabinet that does that. If it isn't loud enough to handle the volume you need on the biggest stage you play, get as many as it takes to walk close to overkill. Multiples of a cabinet you like get even better.

Jim

scottfeldstein · #58 11-19-2012, 10:03 PM

Quote:

Originally Posted by Interceptor

Oh boy.

There are so many variables it can spin your head off. The bottom line is that generalizations are dependent on driver performance being similar across a family line, and the box tuning also being the same. If (and that's huge if) that's the case, your chart is close enough.

But. Ain't nothing the same...

I think my question was pretty much answered then, caveats and all.

Aussie Player · #59 11-19-2012, 11:20 PM

IME I've not heard a 4-10 go as loud w/o breaking up as a 2-15, nor a 2-10 against a 1-15.[/quote]

I agree with this. Also had an 810+2x215's thats 3 cabs driven by 3 heads and the 810 was in a class by itself.

Downunderwonder · #60 11-20-2012, 02:42 AM

My 2x10 isn't quite as loud as my 1x15 either, but it's a much smaller box, not all is equal, dammit.

Quote:

Originally Posted by fdeck

Displacement does not equal volume. While they are related, one is physical and the other is psychological.

Too clever. We should have quit development at sticks on hollow logs, much better for the hearing, no brain strain.