connecting 4ohm and 8ohm cabs

[Ohabanero]

Ok guys thanks for the info. I have a bunch of small cabs and was just trying to figure out the best way to pair a couple of them for a little more and or different sound and I pretty well understood how the series parallel stuff behaved but there's obviously more to it than that. I appreciate your help so promptly. When searching about this type of stuff on already posted it can be a sea of info to wade through to try and find what your looking for. So to get where I got before you guys chimed in I had read a few things like these which would be helpful for anyone just trying to understand the basics.

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Although I think both these are geared toward guitarist types I guess we are just low end guitarist types

 

[walterw]

I have a bunch of small cabs and was just trying to figure out the best way to pair a couple of them for a little more and or different sound

what all cabs exactly? run from what head?

 

[Ohabanero]

what all cabs exactly? run from what head?

So I've got a homemade 8ohm 212 eminence, 2 ampeg 112's (a 4 and an 8), and 3 115 cabs. 2 are JBL 8 ohms and one is gk All have horns except the 212. The ampeg 112's are both b1 combo cabs. They were factory at 4 ohm but I have one swapped to an 8 ohm eminence and it pairs very nicely with a 115. the b1 head is 150 watts at 4 ohm with multiple outs. also have a gk 1001rb which I believe is 540 watt using external cabs thru 1/4 and 700 capable with its combo (115)on speakon that I pulled it from which must be a 4 ohm but I'm guessing at that.
just looking to play around with different setups but with all that I have unfortunately my options are limited.
Here are 2 amps...

 

[Coolhandjjl]

I’m waiting for that one guy to suggest adding a resistor to the 4 ohm cab....

 

[Ohabanero]

I’m waiting for that one guy to suggest adding a resistor to the 4 ohm cab....

Well basically that was me already but I didn't know what it was. I just asked earlier if a 4 ohm cab could be paired using some sort of device. Lol. I think the immediate reply was yes that's a resistor. But don't bother.

 

[walterw]

So I've got a homemade 8ohm 212 eminence, 2 ampeg 112's (a 4 and an 8), and 3 115 cabs. 2 are JBL 8 ohms and one is gk All have horns except the 212. The ampeg 112's are both b1 combo cabs.

so out of all of that stuff the only identical pair of boxes you have are two of the three 1x15 cabs? or are those cabs even the same?

the simple answer is that the best bass sound will generally come from two of the exact same cab; that will best allow the lows to "add" together, while running different cabs at the same time can cause some of the sound to "subtract" instead.

 

[Ohabanero]

so out of all of that stuff the only identical pair of boxes you have are two of the three 1x15 cabs? or are those cabs even the same?

the simple answer is that the best bass sound will generally come from two of the exact same cab; that will best allow the lows to "add" together, while running different cabs at the same time can cause some of the sound to "subtract" instead.

Yeah jbl's. I know right!? It was just a mishmash of stuff I got for free or cheap over the years except my gk combo. I've never been really satisfied with 15s though.

 

[Bassdirty]

Yeah jbl's. I know right!? It was just a mishmash of stuff I got for free or cheap over the years except my gk combo. I've never been really satisfied with 15s though.

Personally I'd toss em all (or, sell em) and start fresh. Curious why you've never been keen on 15's though. Something..Missing in them, or too much of something?

15's (and actually all speakers) have come a LOOOOOOOOOOONG way since that .."collection" of items that you accumulated "over the years". (nothing personal, tech just advances is all).

Just for funnys, (if ya can) find a Mesa dealer, and stack up a pair of Subway 15s and plug in your favorite amp, or a Mesa head.. or almost any head really. Plug in bass. Give em a rip and post back.

I'm not saying I know more than anybody, heck, I don't even know more than me, and that's sayin something.

I am saying - give some "newer" 15's a shot, you might be, nay, WILL be surprised. These aint grandad's 15's these days.

T$

 

[Ohabanero]

Personally I'd toss em all (or, sell em) and start fresh. Curious why you've never been keen on 15's though. Something..Missing in them, or too much of something?

15's (and actually all speakers) have come a LOOOOOOOOOOONG way since that .."collection" of items that you accumulated "over the years". (nothing personal, tech just advances is all).

Just for funnys, (if ya can) find a Mesa dealer, and stack up a pair of Subway 15s and plug in your favorite amp, or a Mesa head.. or almost any head really. Plug in bass. Give em a rip and post back.

I'm not saying I know more than anybody, heck, I don't even know more than me, and that's sayin something.

I am saying - give some "newer" 15's a shot, you might be, nay, WILL be surprised. These aint grandad's 15's these days.

T$

Missing yes. I guess the higher mids and punchy that I hear out of smaller driver rigs. You're a Mesa fan I guess? Maybe I should check those out. Certainly never heard anything bad about them. I bought the gk to get the power I needed for a band and sent a 210 700rb combo back immediately because it sounded too farty at high volume. at lower volumes it had a killer sound. were into blues jazz funky stuff. The 1001 115 did it for me then in comparison but now I realize I miss some mid range and cut through the mix capability playing on only that. It's plenty loud as I can overpower everyone else but to keep things cool I can't be doing that and we don't have the best sound system so the mix relies more on my amp than the other players. 3 and 4 piece band. I really like the combo of the small ampeg b1 with 1 JBL added. Maybe we just need to upgrade our system but I wouldn't be against looking at a 410 115 setup or something like that. Just been getting by with as is and my gas has been focused on axes of late. A big 10 driver rig might behave totally different than the 210 rig I tried but I always thought I wanted a 15 in there for that real low down but somebody commented here that a number of 10s might actually have a better low frequency response. I don't understand how that'd be possible but not saying it ain't true. I just have no personal experience playing through a big 10 cabinet. Only the twin I tried. I actually looked around for a while to see if I could get a gk 210 of the same era (circa 2000) hoping to sit it on my 15 but not much around and then I started learning about resistance and realized maybe it wouldn't work out anyway because I think since I got this 115 as a combo it (driver) must be 4 ohms already and the 1001 is very powerful but with that cabinet I'm not sure it could be paired since the amp bottoms at 4 ohms. had I not bought a combo it might be different but gk set this up for max output as a combo so I doubt it's an 8 ohm. What Mesa cabs do you use/like?

 

[walterw]

I really like the combo of the small ampeg b1 with 1 JBL added. Maybe we just need to upgrade our system but I wouldn't be against looking at a 410 115 setup or something like that.

see, that's what you need to let go of, the idea mixing different kinds of speakers together is supposed to be an improvement; it's generally not. also the idea that a 1x15 will have "more lows" than a 4x10, generally not true either.

the combo with the 1 jbl under it is better than the combo by itself because it's taller with more speakers, making it louder and bigger sounding. chances are a similar-size and power stack with speaker cabs that all matched would be better still.

try the two jbl cabs stacked up under a bass head, that might be all you ever need.

 

[ak56]

Ok. That's kinda what I figured too. So then on top of that do you or anyone here know of any "devices" that you could run a feed into that increases the resistance of 1 cabinet? For example. Say I have a combo amp that's running an 8 ohm 12" driver but is rated to put out more wattage to 4 ohms. If I have a cab that's 4 ohms (also a 12) can it be bumped to 8 somehow (for a combined 4 ohms running both together) by running it into some sort of box first then to the cab. I thought I saw some sort of thing long ago on the web but now I can't seem to locate such an animal.

Won't help at all. Any black box to change the impedance of a cabinet is going to it by resistance. So any extra power will simply turn in to heat in the box. The audio output will be the same and the amp will work harder is all.

There is one device that would work to increase a 4 ohm cab to 8 ohms if installed in series with the 4 ohm cab without all the power generating heat.

Another 4 ohm cab.

But if you're going to do that...

 

[Passinwind]

There is one device that would work to increase a 4 ohm cab to 8 ohms if installed in series with the 4 ohm cab without all the power generating heat.

Another 4 ohm cab.

But if you're going to do that...

A transformer will work too (Peavey and Glockenklang sell or have sold them), if you love unnecessary weight and expense.

 

[Avezzano]

Would the 4x10 always be louder than the 115? at 2/3, 1/3 im not sure the 115 would do what i'm looking for.

There is another huge factor to be considered. Leave aside the impedence and power distribution on two different cabs issue for a moment: NEVER (n-e-v-e-r) mix on the same frequency range different cabs. It's a false myth that you have the best of both worlds, a fantastic set of speakers, coupling a 4x10 plus a 1x15. Either you'll couple two 4x10 cabs or two 1x15. Make some search around... (My 2 c)

EDIT: Sorry! Already addressed in some entries before (quote here below)!!! But I will leave my comment anyways.

the simple answer is that the best bass sound will generally come from two of the exact same cab; that will best allow the lows to "add" together, while running different cabs at the same time can cause some of the sound to "subtract" instead.

Yes: it makes the overall sound "confused and somehow dirty"

 

[agedhorse]

There is another huge factor to be considered. Leave aside the impedence and power distribution on two different cabs issue for a moment: NEVER (n-e-v-e-r) mix on the same frequency range different cabs. It's a false myth that you have the best of both worlds, a fantastic set of speakers, coupling a 4x10 plus a 1x15. Either you'll couple two 4x10 cabs or two 1x15. Make some search around... (My 2 c)

EDIT: Sorry! Already addressed in some entries before (quote here below)!!! But I will leave my comment anyways.


Yes: it makes the overall sound "confused and somehow dirty"

Actually, there are 2 myths and one of them is the myth that you are suggesting!

If the cabinets are designed specifically to work together, including the science and math behind the equations that describe the performance (which do not contain any reference to driver diameter), then different driver sizes may in fact work very well.

On the other hand, drivers of the same diameter often have different enough parameters that they do not work well together. Add that to different cabinet design (alignment, ported versus sealed, etc) and there's the likely possibility that such a pairing I'll work poorly together.

"Always" and "never" are words that need to be used very carefully in order for them to hold true.

 

[Avezzano]

Well, you're right: "always" and "never" should... "never" be used on a highly volatile matter like this! But on the other hand: how sure can one be that a 1x15 cabinet from a given company has been designed with the "precise intention" to be used with their 4x10, just to stay on the example? I would never couple different speakers on the same range. Furthermore, I was just reporting what I've read here on TB on a specific old thread (and on several others) in which the "no mix" assumption was given as one of the well known truths. And Inhave no problems in believe on this. I would safely prefer using two equal Peavey 4x10 versus one Peavey 4x10 mixed with a Peavey 1x15 (always as an example). But right you are: "No mix" indeed should also include a 2x10 Markbass with a 2x10 Ashdown, just to be clear.

 

[JTE]

A transformer will work too (Peavey and Glockenklang sell or have sold them), if you love unnecessary weight and expense. View attachment 3742652

I bought one of those Peavey Auto-formers back in the '80s. Carried it around bolted inside an Army surplus ammo box with input and output jacks all so I could get the negligible difference out of my M3000 power amp seeing 2 ohms no matter the load. Then went further and bolted it inside my MK IV head (first version Mk IV with the Auto-Mix). The audible difference between 300 WRMS @ 2ohms and 210 WRMS @ 4 ohms was nil. Much like Nigel Tuffnel's "But these go to ELEVEN!"

 

[agedhorse]

Well, you're right: "always" and "never" should... "never" be used on a highly volatile matter like this! But on the other hand: how sure one can be that a 1x15 cabinet from a given company has been designed with the "precise intention" to be used with their 4x10, just to stay on the example? I was just reporting what I've read here on TB on a specific old thread (and on several others) in which the "no mix" assumption was given as one of the well known truths. I would safely prefer using two equal Peavey 4x10 versus one Peavey 4x10 mixed with a Peavey 1x15 (always as an example). But right you are: "No mix" indeed should also include a 2x10 Markbass with a 2x10 Ashdown, just to be clear.

May I respectfully suggest that you spend some time learning about the science and math behind speaker theory? This way, you will understand more about why how the myths developed, and why they may or may not hold true in specific cases or combinations. When you understand the equations that govern speaker performance, you will see that speaker diameter is not a variable that matters (for this purpose). Then, you won't be so quick to spread these myths.

The myths can be both right or wrong depending on the specific designs of the cabinets themselves.

I encourage learning about this stuff, it's fascinating.

 

[Avezzano]

I respectfully ask you, out of sincere curiosity: should you choose between a 4x10 plus 1x15 system and a two 4x10 which one would you buy? But thanks for the input, obviously.
P. S.: I will make my homework! But if you want to spend some time, just out of curiosity, read Bill Fitzmaurice and others in the thread "mixing cabinets and phase response". It is a nice and enlightening reading. That thread alone prevents people from spreading misconceptions.

 

[agedhorse]

I respectfully ask you, out of sincere curiosity: should you choose between a 4x10 plus 1x15 system and a two 4x10 which one would you buy? But thanks for the input, obviously.
P. S.: I will make my homework! But if you want to spend some time, just out of curiosity, read Bill Fitzmaurice and others in the thread "mixing cabinets and phase response". It is a nice and enlightening reading. That thread alone prevents people from spreading misconceptions.

Sure, Bill's comments about phase response apply, though Bill also has a reputation for being fundamentally unyielding in his views.

What I am talking about is understanding what governs the phase response performance and designing cabinets (with appropriate drivers) to produce phase response that delivers the intended acoustic response when the two cabinets are combined.

The reason for doing this is in order to take advantage of specific aspects of a driver (such as mid voicing, low frequency extension, harmonic distribution at higher SPL) that can not be achieved by using a single driver or single design.

There are designers and companies that have an established and verifiable history of designing such products, and there are companies that do not. This is where my "always" and "never" comments apply.

 

[agedhorse]

Regarding your question about mixing a 115 and 410 speaker system, in general it's not something I would recommend but for entirely different reasons. In general (though there are exceptions for sure), the sensitivity and power handling differences do not make an ideal pairing. That said, a 215 with a 410 maybin fact be a good combination if the cabinets were designed with phase response and acoustic response performance in mind by a skilled designer.