4 ohm vs. 8 ohm cabinet

[fsbmusic]

Howdy folks. I'm about to buy an SWR golight 4x10 and am deciding between the 4 ohm and the 8 ohm. I rarely do gigs where I need more than one cabinet so I could probably get away with the 4 ohm, but then I'd lose the flexibility to add another cab if need be.

My question is: Is there a significant volume increase with a 4 ohm cabinet over an 8 ohm, or should I get the 8 ohm to be able to add another cab if I need one at some point?

Thanks!

 

[JxBass]

What head are you pairing it with?

 

[fsbmusic]

Right now I've got a GK 400RB. Planning on picking up an SWR head at some point, but it's the GK for now.

 

[countbassiedad]

Interesting question. Subscribed.

 

[JimmyM]

You'll get a bit of a volume bump when running a solid state head at 4 ohms, but it's nothing significant and it manifests itself mostly as extra headroom. I'd go 8 just for the expandability factor alone.

 

[Ben Heard]

You'll get a bit of a volume bump when running a solid state head at 4 ohms, but it's nothing significant and it manifests itself mostly as extra headroom. I'd go 8 just for the expandability factor alone.

+1

Also, I think (correct me if I'm wrong) a more efficient 8 ohm cab versus a not so efficient 4 ohm cab could result in around the same volume.

 

[KJung]

This question does not have an overall, simple answer that can be applied to all situations. It depends on the power of the amplifier, the efficiency of the cabinet, and the powerhandling and mechanical capability of the cabinet (assuming we are talking about solid state power sections).

All these things work together. So, the answer is 'in some cases it will make no difference whatsoever (i.e., a 112 cab with an amp that puts out 500 watts into 8ohms), and in other cases (the OP's specifically), it can make a noticable difference (i.e., a multidriver, high quality cab combined with a relatively low powered amp).

The volume increase will, on average, but about 2db+, which is pretty close to the same db increase you get adding a second cab to a tube amp (i.e., the impact of doubling drivers without a power increase). So, definitely 'noticable', but surely not 'life changing'. What the OP will notice with his relatively low powered head and a cab that can actually use the additional wattage mechanically (i.e., it won't fart out with the additional power that the 4ohm version of the cab will allow to be generated by the head) is a cleaner, wider, more open low end, a bit more absolute volume (you won't notice it until the end of the night when you are really pushing it), less compression and low end drop off when digging in or slapping.

So, in the OP's case, if he KNOWS (like many of us) that he would never use more than a single 410 on the gig, IMO getting the 4ohm version of the otherwise identical cab is a bit of a no brainer. If for some reason, though, the OP thinks he might add a second 410 in the future, then the 8ohm would be a prudent choice, even if you give a bit up on single cab usage.

IMO and lot of IME on this one!

 

[BassmanPaul]

If you plan on changing your amp in the future to one that can cope with a 2Ω load I'd go with 4Ω. That includes amps with a "stereo" output section. You can then get a second 4Ω cabinet and run them one per channel.

If you plan on keeping the GK then 8Ω is the way so that you can add a second 8Ω cabinet. This will be at the 4Ω minimum impedance of most regular bass amps.

I went with 4Ω as I was going to power them with a stereo power amp. Most stereo power amps will happily run at 2Ω per channel. I've run many times with all four of my 4Ω cabinets connected. Not really necessary but a lot of fun anyway.

 

[KJung]

Also, I think (correct me if I'm wrong) a more efficient 8 ohm cab versus a not so efficient 4 ohm cab could result in around the same volume.

While that isn't relevant here, since the OP is talking about 4 versus 8ohm version of the same cab, this can be very important when comparing a relatively low efficience design (like the 3012LF loaded boxes) with a more efficient design (like a more typical mid driver loaded box). For example, with the same head (a Markbass F500), the maximum volume of my Thunderchild112 (4ohm 3012LF relatively low efficience cabinet) is about the same as my 8ohm, Bergantino AE210 (relatively high efficience cabinet).

Of course, the Thunderchild will put out more absolute low end prior to compressing, since that is one of the rare single 12" drivers that can actually use the 500 watts of a typical micro head at 4ohms.

So, anyone who tells you 'it doesn't matter in general' or anyone who tells you 'it makes a huge difference in general' is not really providing useful info IMO. It all depends! Since so few cabs are available in both 8ohm and 4ohm version, most of the time, it is a moot point... you take what you can get. However, with SWR, Epifani and a few others, the decision can be important.

 

[JTE]

I can tell you from personal experience to get the 8 ohm box. In '98 I had the same choice to make when buying a new cabinet for my Eden WT-400. The amp is rated at 400 WRMS @ 4 ohms, and about 235 WRMS @ 8. I figured I'd never need another cabinet and getting the extra 41% power was important. So, I got an Eden D410XLT-4. A friend of mine liked my rig and bought a similar set up, but he got an 8 ohm cabinet. We compared them once, swapping heads back and forth to account for individual differences in amps, and used another borrowed D410XLT-8. The side-by-side comparison of the 4-ohm cabinet and the 8-ohm cabinet showed a barely (and quite possibly false impression) noticeable increase in volume from the 4 ohm box.

But, running a pair of 8-ohm D410XLTs was a HUGE change in sound, just huge. So, my advice is to always allow yourself the option of adding more speakers, because that will move more air than more power. See, I too thought I'd never need more than one speaker cabinet. But the band took off in a way I'd never imagined and I soon found myself playing regularly in situations where I really needed more speakers. It cost a good deal more to buy another amp to drive the second cabinet I got.

John

 

[KJung]

I can tell you from personal experience to get the 8 ohm box. In '98 I had the same choice to make when buying a new cabinet for my Eden WT-400. The amp is rated at 400 WRMS @ 4 ohms, and about 235 WRMS @ 8. I figured I'd never need another cabinet and getting the extra 41% power was important. So, I got an Eden D410XLT-4. A friend of mine liked my rig and bought a similar set up, but he got an 8 ohm cabinet. We compared them once, swapping heads back and forth to account for individual differences in amps, and used another borrowed D410XLT-8. The side-by-side comparison of the 4-ohm cabinet and the 8-ohm cabinet showed a barely (and quite possibly false impression) noticeable increase in volume from the 4 ohm box.

But, running a pair of 8-ohm D410XLTs was a HUGE change in sound, just huge. So, my advice is to always allow yourself the option of adding more speakers, because that will move more air than more power. See, I too thought I'd never need more than one speaker cabinet. But the band took off in a way I'd never imagined and I soon found myself playing regularly in situations where I really needed more speakers. It cost a good deal more to buy another amp to drive the second cabinet I got.

John

Yes, doubling the drivers and almost doubling the cone area will always win big time (around a 5db increase over a single 8ohm cab). However, realize you will not notice a volume difference between identical 4ohm or 8ohm cabs by just switching the head back and forth at the same knob settings. The 4ohm will allow you to crank the head without compression at higher volumes.

Again, the decision with a lower powered head is if you would even need to cary dual 410's (in this case) around. If you need massive volume, then two 8ohm 410's (assuming you have a solid state head limited to 4ohms minimum) would be the way to go. If you are a player who doesn't need to play any louder than the loudest unmic'd drummer (not sure why ANY player would need to do that, but I guess there are situations), then a good quality, single 4ohm 410 or 212 with an appropriately powered head is a wonderful thing.

Edit: You make a great point though... PLAN your cab purchases and needs carefully. Buying a 4ohm cab and then needing a second can limit your head options. Buying an 8ohm cab and never needing another one can result in paying for a 400 watt head, and getting a 250 watt head.

 

[Ben Heard]

While that isn't relevant here, since the OP is talking about 4 versus 8ohm version of the same cab, this can be very important when comparing a relatively low efficience design (like the 3012LF loaded boxes) with a more efficient design (like a more typical mid driver loaded box). For example, with the same head (a Markbass F500), the maximum volume of my Thunderchild112 (4ohm 3012LF relatively low efficience cabinet) is about the same as my 8ohm, Bergantino AE210 (relatively high efficience cabinet).

Of course, the Thunderchild will put out more absolute low end prior to compressing, since that is one of the rare single 12" drivers that can actually use the 500 watts of a typical micro head at 4ohms.

So, anyone who tells you 'it doesn't matter in general' or anyone who tells you 'it makes a huge difference in general' is not really providing useful info IMO. It all depends! Since so few cabs are available in both 8ohm and 4ohm version, most of the time, it is a moot point... you take what you can get. However, with SWR, Epifani and a few others, the decision can be important.

Oops, didn't notice he had specified that it was the same cab in either 4 or 8 ohm cab. I assumed it wasn't as, like you said, this isn't a very common option! You're always good at putting the (relatively) technical stuff into easily understood terms.

To the OP then, if you're absolutely sure you won't have need for a second 410 in your future, I'd say go with the 4 ohm cab for extra headroom should you need it. If this was a smaller cab, say a 210, 115 or 112 (with the exception of designs like the TC) 8 ohm would IMO/IME be the better option, as those cabs can only handle so much to begin with.

 

[MuthaFunk]

FWIW I would pic the 4 ohm version in a second. For the gigs I was doing I was able to get by for 10 years with just my 4 ohm Eden D410XLT4 with my WT-400 Plus. I had no room or intention of carting out more cabs. I squeezed all the power I could from my 4 ohm minimum impedance amp and it was enough.

There was a couple (2) occasions where I could have used a larger cab just for kicks (outdoor gigs) but the cost and aggravation of owning and storing a second 410 for those odd occasions wasn't anywhere close to being worth it. Even in those occasions having my "maxed out power" 410 proved to be sufficient because of P.A. support.

It sounds like the OP is doing similar gigs to the ones I've done over the years and just don't require that much volume. I haven't needed that 410 for the past 2 years now as 212's have been even enough for me.

 

[Eric Swaim]

I use two 8 ohms SWR Son Of Bertha Bass cabs with my SWR SM400S, I probably would have wanted two 4 ohms. However, I can run my SWR Bridged and get as loud as I need too. I would get the 4 ohm and be happy otherwise you will get the 8 ohm and wonder "why do I have to crank my volume up louder" to get the power of a 4 ohm cab. Your going to lose about 30% if you go with an 8 ohm. It's all about the matchup between the head and the cabs and the ohms each are rated. It's so much easier explaining over the phone.

 

[will33]

Howdy folks. I'm about to buy an SWR golight 4x10 and am deciding between the 4 ohm and the 8 ohm. I rarely do gigs where I need more than one cabinet so I could probably get away with the 4 ohm, but then I'd lose the flexibility to add another cab if need be.

My question is: Is there a significant volume increase with a 4 ohm cabinet over an 8 ohm, or should I get the 8 ohm to be able to add another cab if I need one at some point?

Thanks!

No, get 8ohm cabs unless you have a specific good reason not to, like a tube amp that doesn't have an 8ohm tap, or if it's a large cab where you'll only ever need one, like 215, 810, etc.

 

[xander8280]

I use my acoustic 370 with my 1x15 can at 8ohms and also I use my 301 cabinet at 4ohms. They're different brand speakers and sizes(peavey black widow 15" and a cerwin vega 18") I get a huge volume boost from the 4 ohm. But these cabinets are totally different. I'd go with the 4ohm just to have less resistance; and to achieve 2ohms with double cabs.

 

[fsbmusic]

Thanks for the input everyone. Very helpful info. I'm leaning towards the 4 ohm because it's unlikely I'll need more than one cabinet. As much as I'd like to believe I'll be playing stadiums and arenas someday, it probably ain't gonna happen! And at that point they'd be giving me free gear anyway

Just out of curiosity, anyone know what heads out there can handle a 2 ohm load, just in case I get a 4 ohm cab and want to add another? I like SWR gear but I'm curious to know what else people like.

Thanks!

 

[KJung]

Thanks for the input everyone. Very helpful info. I'm leaning towards the 4 ohm because it's unlikely I'll need more than one cabinet. As much as I'd like to believe I'll be playing stadiums and arenas someday, it probably ain't gonna happen! And at that point they'd be giving me free gear anyway

Just out of curiosity, anyone know what heads out there can handle a 2 ohm load, just in case I get a 4 ohm cab and want to add another? I like SWR gear but I'm curious to know what else people like.

Thanks!

In the Micro amp category, the Carvin BX500 is 2ohm safe. The Genz Shuttle Max 12.2 is fabulous. A bit larger than a micro, but still featherweight, with two separate 4ohm minimum amps that can really push two 4ohm cabs.

Not sure if SWR still makes the SM900, but that can also be run like the Max 12.2, driving two 4ohm cabs, one from each side in 'non bridged mode'.

 

[Ben Heard]

Adding to the 2 ohm stable micro list, there's the Euphonic Audio Micro 550 as well. Genz Benz had the now discontinued NeoPak 3.5 that was 2 ohm stable (and put out 350W @ 4, 500W @2) and Mesa has the Walkabout which is stable down to 2 ohms as well. Those last 2 are not quite micro though, the NeoPak is not big by any means but not the smallest package either coming in at 8 1/2lbs or so and the Walkabout is 13lbs.

 

[sonicblue62]

I searched this thread today and am grateful for everyone's insight as I am also in the market for a new cab. Another question: Do any of the above-discussed factors change if the amp in question is tube rather than solid state? The rig I am considering is an Ampeg v4 with an Avatar 212 cab. One of these cabs is for sale locally at a good price, but is an 8 ohm cab. Should I spend the extra cash on a new 4 ohm cab for maximum headroom? (BTW, if anyone wants to sell a V4 or V4B, let me know).