4ohm 410 cabs.

[Marvin]

I was just wondering what potential benefits and disadvantages there were to using a 4ohm cab.

[Delberthot]

If your amp goes down to 4 ohms then you get the full whack out of your amp but most people would say that there isn't a great deal of noticable difference between what you get at 4 and 8 ohms. Plus from what I've read, your amp will run hotter as well.

Possibly the most noticable difference I think would be if you were using something with lots of speakers like an 8x10" at 4 ohms compared to 8 but then I have never seen an 8 ohm 8x10"

[Marvin]

[quote name='Delberthot' post='1343966' date='Aug 18 2011, 08:05 AM'][b]If your amp goes down to 4 ohms then you get the full whack out of your amp but most people would say that there isn't a great deal of noticable difference between what you get at 4 and 8 ohms. Plus from what I've read, your amp will run hotter as well.
[/b]
Possibly the most noticable difference I think would be if you were using something with lots of speakers like an 8x10" at 4 ohms compared to 8 but then I have never seen an 8 ohm 8x10"[/quote]

This is what I was wondering mostly. If there isn't a significant difference between 4 and 8ohm for the same number of speakers then an 8 would be better I suppose as it could be added to.

[bartelby]

[quote name='Delberthot' post='1343966' date='Aug 18 2011, 08:05 AM']Plus from what I've read, your amp will run hotter as well.[/quote]


That might explain my problem with my PF-500 then...
[url="http://basschat.co.uk/index.php?showtopic=151163"]http://basschat.co.uk/index.php?showtopic=151163[/url]

Edited August 18, 2011 by bartelby

[xgsjx]

I think EBS make 4 ohm cabs because their amps will run fine at 2 ohm.
But yes to the above, getting "full whack" from your amp usually means a 3 db increase in volume (which is barely noticeable) & having a cab that takes everything from your amp means you can't add another cab unless you run it parallel, & then you're gonna be running the amp at 8 ohm & getting less watts going to each cab.

[chris_b]

Amps running hotter into 4 ohm are operating as designed and any heat will not be a problem for the amp, as long as you haven't restricted the airflow.

A lot will depend on which amp and which cab, but a 4 ohm cab gets the full power of the amp, asssuming a 4 ohm maximum load. The extra volume isn't the benefit but the tone of an amp supposedly sounds slightly better and fuller when the amp is running at 4 ohm.

The main difference for me is that you can’t add another cab but how loud do you need to go? I haven’t needed more than a 410 for many years.

[casapete]

I have two 4x10 cabs of identical type, one is 4 and the other is 8 ohms.
To my ears the 4 does sound better - bit louder/fuller, but there's not a lot in it TBH.
Always choose the 4 for a one cab solution, and occasionally use the 8 on its own ,or
with a matching 8 ohm 1x15 for really loud/big gigs
I use the 4 with a Markbass LM2 which never gets hot - am pretty sure amps are designed
to drive the right speaker load these days, so if it says min load 4 ohms then it should be fine!

[Marvin]

[quote name='chris_b' post='1344015' date='Aug 18 2011, 08:46 AM']Amps running hotter into 4 ohm are operating as designed and any heat will not be a problem for the amp, as long as you haven't restricted the airflow.

A lot will depend on which amp and which cab, but a 4 ohm cab gets the full power of the amp, asssuming a 4 ohm maximum load. The extra volume isn't the benefit but the tone of an amp supposedly sounds slightly better and fuller when the amp is running at 4 ohm.

The main difference for me is that you can’t add another cab but[b] how loud do you need to go?[/b] I haven’t needed more than a 410 for many years.[/quote]

Not as loud as the bass player I saw Saturday evening . 500w head through a 410 + 115 - stupidly loud. Even I wanted him to turn it down. I'm sure just the 410 would have done a good job.

[NJE]

I use a MarkBass LM2 with an EBS 4X10 at 4 ohm and it is VERY loud. I have been to a rehearsal with a 8 ohm Orange cab (not mine) and I had to crank the head more to get the same sort of volume out of it. That could be the Orange cab though.

As far as running hot, my LM2 doesnt even really get warm let alone hot and it runs for about 4 hours at a time. Its a perfect solution for me as I have no intention (at the moment) to have any more than one cab, but if I need or want to go bigger in the furture the cab or head will need to go which could be a pain.

[waynepunkdude]

The reason I have a 4OHM cab is because my head is 4 or 2 OHM all valve so an 8OHM cab will cause damage.

[Bill Fitzmaurice]

[quote name='Marvin' post='1343962' date='Aug 18 2011, 02:59 AM']I was just wondering what potential benefits and disadvantages there were to using a 4ohm cab.[/quote]
To using it? Only a very modest increase in output, if any, while making it impossible to run a second cab if your amp doesn't have 2 ohm capability. The exception is a valve amp that has no 8 ohm tap.
To offering it? So you won't lose a sale to someone who 'needs to get all the watts out of my amp', even though doing so is of little to no value.

[EdwardHimself]

From what i've read, the actual amount of speakers and volume of cabinetry is more important to how much sound you actually get put out rather than just having as many watts as possible being put out. If you want loudness, you're better off getting an 8 ohm 4x10 and another 8 ohm cab rather than a 4 ohm 4x10. Of course that is a bit more difficult to lug about.

Edited August 18, 2011 by EdwardHimself

[Lozz196]

[quote name='Marvin' post='1343973' date='Aug 18 2011, 08:09 AM']This is what I was wondering mostly. If there isn't a significant difference between 4 and 8ohm for the same number of speakers then an 8 would be better I suppose as it could be added to.[/quote]

Definately - using my Barefaced Compact on its own, or using the Midget with it as well, the actual volume level doesn`t change that much, but the size of the sound does considerably - a lot fuller.

Had the same with my Ampegs when I had them - I had an SVT410HE, which I used for practices, and at gigs, added an SVT210HE. Not much difference in volume, but due to more speakers, and the added height, was a lot more full, and easier to hear.

So I`d recommend the 8 ohms, because as you say, you can add to it at a later point if you need to.

[cureswhatailsye]

I just swapped 2 8Ohm Aggy 112 cabs for an old Eden 4ohm 410 and for me the 410 blows the stack out of the water.

Literally twice the headroom - for a function band gig with everything through the front I was limiting my head at 1 o'clock output volume with the 112s just to hear myself - with the 410 it sits at about 9 o'clock. (I know that this probably has a lot to do with the amount of speaker area etc).

Having said that, I used an 8ohm Ashdown 210 for ages and it was great and always loud enough. Swings and roundabouts I guess!

[Lozz196]

I think that`s down to Eden cabs being very loud. My 8 ohm Eden Nemesis 410 was easily the loudest cab I`ve had, by far. The same amp I use with my two Barefaced cabs on 4 or 5, I couldn`t use through the Eden on more than 3, 3.5 pushing it, as it would overpower everyone else in the band.

[cureswhatailsye]

[quote name='Lozz196' post='1344676' date='Aug 18 2011, 06:11 PM']I think that`s down to Eden cabs being very loud. My 8 ohm Eden Nemesis 410 was easily the loudest cab I`ve had, by far. The same amp I use with my two Barefaced cabs on 4 or 5, I couldn`t use through the Eden on more than 3, 3.5 pushing it, [b]as it would overpower everyone else in the band[/b].[/quote]

You say this as if it's a bad thing (My inner guitarist bursting to get out)

[Lozz196]

That is indeed your inner guitarist. The dark side can seem very alluring, but you must resist!

[Ed_S]

Maybe I'm in a minority, but I always buy cabs in their 4ohm variant when possible. If I'm only taking one cab out (98% of the time), it means that I get the most out of the rig; even if the difference in output is small on the cosmic scale, it's there. On the other hand, if I'm going mad and taking two cabs (usually more for visual impact), then I can either use a serial box to run the two at 8ohms, take both my terror and little mark and slave one of them, or more likely, use my rack rig which has a stereo power amp that runs very happily with a 4ohm load on each channel. As long as you've actually thought about how you want to use whatever you buy, I don't see the problem.

[xgsjx]

That is a valid reason to going for 4 ohm cabs, but not everyone has a power amp or 2 separate heads.
Question for you. If using the LMII with 1 cab runs at 500w, does running 2 with your parallel box have any volume increase? It's a genuine Q as I've never tried it & I'm assuming (from doing some of the maths) that you'll have @ 175w going to each cab. I work out that if a 4ohm cab gives a 3db increase over the 8, & 2 8ohm cabs in series gives a 6db increase due to more drivers moving more air, then in theory (without thinking too hard) you probably dont have a big increase if any?

[Ed_S]

[quote name='xgsjx' post='1346138' date='Aug 20 2011, 10:22 AM']That is a valid reason to going for 4 ohm cabs, but not everyone has a power amp or 2 separate heads.
Question for you. If using the LMII with 1 cab runs at 500w, does running 2 with your parallel box have any volume increase? It's a genuine Q as I've never tried it & I'm assuming (from doing some of the maths) that you'll have @ 175w going to each cab. I work out that if a 4ohm cab gives a 3db increase over the 8, & 2 8ohm cabs in series gives a 6db increase due to more drivers moving more air, then in theory (without thinking too hard) you probably dont have a big increase if any?[/quote]

I've not actually tried it with my current heads and cabs, I must admit; it's just never been necessary as they're both capable of drowning an entire band on their own! When I did it with my old amp and two 410s (one mine, one borrowed) it did seem to be marginally louder than just one, but I was always dubious about how much difference was due to the extra speakers, and how much was just the fact that the top one was closer to head-height. If I get chance to try it with my current stuff any time soon, I'll post back with the results.

[ficelles]

My SWR head is a lot pokier into 4 ohms rather than 8 even though it only bumps it up from 120W to 160W... it seems to change the sound as well. The amp does run quite hot but the manual says to expect it to.

ficelles

[Bill Fitzmaurice]

[quote name='ficelles' post='1346366' date='Aug 20 2011, 09:41 AM']My SWR head is a lot pokier into 4 ohms rather than 8 even though it only bumps it up from 120W to 160W... it seems to change the sound as well. The amp does run quite hot but the manual says to expect it to.

ficelles[/quote]
The power increase is moot, so changes in the sound are due to other driver and cab specs. BTW, most 4 ohm rated drivers aren't. For example, the DCR of the average 8 ohm driver is 5.5 ohms. By the same token the DCR of the average 4 ohm driver should be 2.7 ohms, but in fact it tends to run around 3.5 ohms. That makes the impedance of the average 4 ohm rated driver closer to 5 ohms. It gets even more complicated. A two driver 4 ohm cab would be loaded with 8 ohm drivers, so it would be a true 4 ohm cab. A four driver loaded 4 ohm cab would be loaded with either 4 ohm or 16 ohm drivers. 16 ohm drivers tend to have DCR values around 11 ohms, so the impedance of a 4x16 ohm cab would be 4 ohms, that of a 4x4 ohm cab 5 ohms. Then you take into consideration all the other spec differences between different impedance drivers, most notably inductance, and it quickly becomes apparent that the rated impedance in and of itself doesn't count for much.

Edited August 20, 2011 by Bill Fitzmaurice