Multiple cabinets -> matching volume?

[walterw]

Originally Posted by NYCbassist

In my case it's a question. My amp would be putting 225 watts to the 2X10 and 320 watts to the 4X10. So how exactly is the power being divided to make all 6 get the exact amount of power?

no, we're talking about both cabs parallel, straight into one power amp.

that setup gets you the same distribution of power as one 2.6Ω 6x10 cab.

as for the 2x10 not being as loud as the 4x10, of course not! the idea is that the pair would be a bit louder than the 4x10 by itself, just like a 6x10 cab would.

[NYCbassist]

Originally Posted by CL400Peavey

So dual mono set ups aside:

Running a 4 Ohm 410 and an 8 Ohm 210 on a 2 Ohm stable amp, will split the power equally between all 6 drivers.

Okay, Now how about a 1X18 and a 210?? What will be the recommended impedance? I am thinking of this for another Rig that is 2Ohm capable 500 Watts. Are we going to have to start calculating Speaker surface area?

[CL400Peavey]

Originally Posted by NYCbassist

Okay, Now how about a 1X18 and a 210?? What will be the recommended impedance? I am thinking of this for another Rig that is 2Ohm capable 500 Watts. Are we going to have to start calculating Speaker surface area?

I wouldnt recommend pairing those cabs with out running a stereo power amp, preferably with some sort of cross over.

[walterw]

Originally Posted by CL400Peavey

I wouldnt recommend pairing those cabs with out running a stereo power amp, preferably with some sort of cross over.

at which point the 2x10 could probably be swapped out for a 6" mid

(OK, i suppose you could cross them over like a PA stack, down at around 100Hz or maybe 125Hz. the 10s should still be doing something worthwhile at that point.)

[CL400Peavey]

Originally Posted by walterw

at which point the 2x10 could probably be swapped out for a 6" mid

(OK, i suppose you could cross them over like a PA stack, down at around 100Hz or maybe 125Hz. the 10s should still be doing something worthwhile at that point.)

More importantly the cross over will help eliminate potential phasing issues between the two mis matched drivers, and help balance the power distribution.

[walterw]

absolutely.

[NYCbassist]

Originally Posted by CL400Peavey

More importantly the cross over will help eliminate potential phasing issues between the two mis matched drivers, and help balance the power distribution.

I was more thinking of a Peavey 1810 Cab. using the Carvin Bx500. My guitarist has one dirt cheap if I want it. I guess it probably isn't worth messing with.

[lhoward]

I have a somewhat different approach to the idea of mix-and-match cabs. I don't mix dis-similar cabs on the same amplifier channel, only identical ones. I use the preamp output into a stereo power amp with each channel (capable of 2 ohm operation) powering a particular cab or identical cabs. I ensure the thermal power handling of cabs on each channel are fairly close, such as one 4x10 cab on one channel and 2- 15 inch cabs on the other. I don't usually employ this type of system very often, but I have the setup ready to go for high volume requirements such as large venues or outside environments with limited or no PA support.

The problems with using dis-similar cabs, such as one 4x10 and one 15 inch cab results in the 15 inch competing unequally, in terms of thermal and displacement rating, with a 4x10 cab, a competition that it will loose at some point, depending on how hard the entire system is pushed.

I don't like to use cabinets that have a sensitivity of less than 96 dB. The other piece in my signal path is the use of a high-pass filter. I've built my own in the past, but I've been using Francis Deck's product and it works nicely. That keeps frequencies below the effective cab cutoff from over-driving the speaker in the cabinet's infrasonic range which adds nothing of value to the sound of the system. Recall that driving the speaker into its infrasonic zone, where the cone is essentially unloaded, will also result in being driven beyond is xmax limit beside wasting amplifier power on the infrasonics. Excursion-limited power handling is usually below the thermal power limit and so controlling the cutoff/infrasonic frequency range is an important consideration for me.

That's a somewhat simplistic view of trying to keep my signal path clean irregardless of brand and size of cabs used considering my caveats above.

Lloyd Howard

[NYCbassist]

Originally Posted by Bass_Pounder

That is the problem.

You are taking only partial knowledge and trying to use it "across the board"

Your wisdom states that if I connect a 2X10 cab and a 4X10 cab, that I should make sure the impedance matches. That would be a 50/50 power split between the two cabs.

My knowledge tells me that in the same scenario I would want to mix a 8 ohm 2X10 with a 4 ohm 4X10. That would provide 33/66 split between the two cabs.

Since you are running a total of 6 tens (one cab has 2/3 of the total speakers and the other has 1/3 of the speakers) which do you think is the better match:

1/2 the power to 1/3 the speakers + 1/2 the power to 2/3 of the speakers ?

OR

1/3 of the power to 1/3 of the speakers + 2/3 the power to 2/3 the speakers ?

I can't say I fully understand this but is definitely a real world scenario as opposed to a 1x15 & 8x10 combo. The only problem comes in when it's not all 10's and you throw a 12 or 15 into the mix. When I ordered my Avatars, It seemed pretty cut & dry to go 4 Ohm. I'll admit that right now I'm not sure it was the perfect match but it sounds killer.

[walterw]

agreed that trying to add a 1x15 cab to an 8x10 setup is goofy and not likely to happen in the "real world".

Originally Posted by NYCbassist

The only problem comes in when it's not all 10's and you throw a 12 or 15 into the mix.

this is why just "throwing" different speakers "into the mix" is usually a bad idea.

[NYCbassist]

Originally Posted by walterw

agreed that trying to add a 1x15 cab to an 8x10 setup is goofy and not likely to happen in the "real world".

this is why just "throwing" different speakers "into the mix" is usually a bad idea.

Very True but Many people do use a 1X15 and 2X10. I like it quite a bit but I Knew nothing about The math/Science behind it when I put it together. I know that Peavey 1510's Use 1 4 Ohm 15" and 2 8 Ohm 10" drivers. This exactly what I essentially have. But after the discussion's in this thread It seems like many don't approve of the Combo. Or at least the Impedance choice.

[countrybass007]

JimmyM nailed it, mixed cabs need an amp with each cab.

[walterw]

at least a single 15 and a 2x10 have somewhere close to the same speaker area and somewhere close to the same volume. it's the 4x10 over the 15 that's really unbalanced.

[DJ Bebop]

Originally Posted by NYCbassist

I was more thinking of a Peavey 1810 Cab. using the Carvin Bx500. My guitarist has one dirt cheap if I want it. I guess it probably isn't worth messing with.

Try it, I have one that I have used with my Carvin BX1500.
I found it work better bi amped because I could control the volume between the tens and 18. It still sounded fine full range
ie using the built in crossover.

[NYCbassist]

Originally Posted by DJ Bebop

Try it, I have one that I have used with my Carvin BX1500.
I found it work better bi amped because I could control the volume between the tens and 18. It still sounded fine full range
ie using the built in crossover.

Thanks, I'm supposed to play it on Sunday.

[CL400Peavey]

The carvin BX1500 is an incredibly versatile amp. One of the few amps out there that still gives me a bit of gas...

[Bassmec]

Originally Posted by countrybass007

JimmyM nailed it, mixed cabs need an amp with each cab.

I have found this to be the main trick to mixing cabs, to have an amp eq'd to the requirements of each different sized driver in your rig is of paramount importance as an amp eq'd to drive a bright forward midrange 15" cab with no tweeter will sound rubbish driving a modern VLF hyped four by ten with one.
As long as you can arrange to get the cabinets wired in the same polarity the difference in the frequency/phase twist between a 10" full range driver and a 15" full range driver is only really relevant when testing in an anechoic chamber. It is of course utterly irrelevant to any bass rig that then goes on to be amplified by either microphones on purpose or via spill or DI into any other loudspeaker system like the PA or stage monitors.
As too handling power and getting levels correct between each driver
type, if attempting mixed drivers using only using one amp. Nobody has so far pointed out that the sound pressure level of the speaker in question is what's relevant here. For instance there are some gob smackingly efficient fifteen inch drivers like Altec 418's or JBL 130's
That produce average SPL figures in the range of 105 to 103 dB SPL 1 watt 1 m. So a series parallel wired 8 ohm 4 x 10 using modern drivers that are designed to produce extended bass response may only get an SPL of say 95dB 1 watt 1 m per driver and even with close coupling 4
of them is not going to get the 4x10 to be as apparently loud as the single lansing designed fifteen for a given power level.
So the only scientific question that remains is do you have enough speaker power handling to do your job, without blowing up any of them.
No your rig is not limited by the fifteen inch drivers thermal rating
It is however limited by the volume at which it begins to fail to produce
clean clear bass sound.

[Mancub02]

Originally Posted by bassgod0dmw

Have a look in the FAQ at the top of the page, or search out "mixing cabs" or "mixing drivers" You'll have enough reading/arguing to keep busy for quite a while.

To answer your question, it's not possible to control the volume of two different cabinets. It's a big reason why many people do not like the ol' 410 + 115 stack. The 115 can't keep up with the 410, so you never hear it suffering...then...BOOM. You just blew the 115.

I recently bought a Peavy T-Max and was impressed that the crossover frequency can be selected as well as the balance between cabinets. I'm not sure how common these options are in other amps but may be a way to control individual cabs.

best....

[Bmorefoozler]

Originally Posted by NYCbassist

Very True but Many people do use a 1X15 and 2X10. I like it quite a bit but I Knew nothing about The math/Science behind it when I put it together. I know that Peavey 1510's Use 1 4 Ohm 15" and 2 8 Ohm 10" drivers. This exactly what I essentially have. But after the discussion's in this thread It seems like many don't approve of the Combo. Or at least the Impedance choice.

IF you MUST mix 15's and 10's, you SHOULD mix them at a ratio of 1:2 and the 15's having the same impedance as each PAIR of 10's. This is becuase, roughly speaking, each pair of 10's will have roughly the same sensitivity and power handling as each solitary 15.

IN the case of the dreaded 410/115 matchup, it would actually be a wiser choice to use a 2ohm amp with a 4 ohm 4x10 and an 8 ohm 115. While you correctly point out that the 15 would be barely audible, it would actually SURVIVE near the max volume levels capable of the entire rig as a whole. If you wanted their volumes to match, you would actually want it the other way around(4 ohm 15, 8 ohm 4x10) as the sensitivity rating of the 410 is greater. While in this scenario the volume levels would be roughly equal, the 15 would blow LONG before the 4x10 breaks a sweat, making it a TERRIBLE matchup.
TO go further, if you wanted to add 15's to an 8x10, it would be wisest to add 2 8ohm 215's to a 4 ohm 810. This would allow max volume and safety factor.

All of this post ignores the MANY other reasons NOT to mix cabs, and ONKLY addresses getting equal power distribution. There are indeed plenty of other reasons to stick with like cabs.

[Bass_Pounder]

Originally Posted by Mancub02

I recently bought a Peavy T-Max and was impressed that the crossover frequency can be selected as well as the balance between cabinets. I'm not sure how common these options are in other amps but may be a way to control individual cabs.

best....

Lots of head can bi-amp, however it really does not solve anything.

Bi-amping with a 1X15 and a 4X10 is a waste because you are now carrying around a 4X10 to do the work of a single 6" mid speaker.