8ohm vs 4ohm cab?

[lowendgalore]

Probably a questions thats been done before...

But im looking at a Markbass 104hf cab

Theres a 4ohm or 8ohm option;
Someone just verify with me the difference !

Cheers!

Edited November 23, 2014 by lowendgalore

[skidder652003]

well if you want to add another cab at a later date you're probably better off with the 8 ohm cab as 2 x 8ohm cabs goes down to a 4 ohm load on the amp, whereas 2 x 4 ohm cabs goes down to a 2 ohm load on your amp and quite a few amps only go down to 4 ohms rather than 2. Theres not a massive difference in volume between 8 and 4 ohm cabs IMO. Does that make sense?, Im crap at explaining stuff.
Just to confuse matters further, if your amp is solid state, what i just said is fine but if its a valve head, you should put it with whatever the amp says it should be paired with

Edited November 23, 2014 by skidder652003

[88reaper88]

[size=3]Ohms are units/measurements of resistance. [/size]
[size=3]In a nut shell: More ohms = harder for the signal to get through = less wattage from the amp. [/size]
[size=3]But due to crazy maths and physics and planets aligning this can be combatted by adding Ohms (more cabs) through the correct wiring. [/size]
[size=3]For example, Two 8ohms cabs going into a head, wired in parallel will produce a total resistance of 4ohms = all the watts of the heads are 'used'. [/size][size=3]But two 8ohms in series will give you 16ohms[/size]
[size=3]There's literally thousands of threads/website/YouTube videos on the subject [/size]

[lowendgalore]

Sweet thanks for reply guys!

Yeah i understand about the dropping ohms when using 2 cabs for example.
I was just wondering same amp and the 2 same cabs one of which is the 4 ohm and the other the 8 ohm what will i hear different?

cheers

[Dad3353]

[quote name='lowendgalore' timestamp='1416754426' post='2613176']
Sweet thanks for reply guys!

Yeah i understand about the dropping ohms when using 2 cabs for example.
I was just wondering same amp and the 2 same cabs one of which is the 4 ohm and the other the 8 ohm what will i hear different?

cheers
[/quote]

All things being equal elsewhere, the 4 Ohm cab will sound slightly louder.

[88reaper88]

If you think of the signal being people and the cabs being doors into a venue, the bigger door (less resistance, 4ohm) will have more people going through it then a smaller door (more resistance, 8ohm)

[Dad3353]

Pure pedantry, but...

The Ohms used in this context refers to impedance, not resistance. What's the difference..? In simple terms, resistance is used for DC measurement, impedance for AC, where frequency becomes a factor. If we measure the DC resistance of an 8 Ohm cab, it will not show 8, but something like 5 Ohms. Impedance is measured with AC (ie: not an ordinary multimeter...) and will vary depending on frequency. Nominal impedance is usually measured at 400 Hz.

Just sayin'...

[stevie]

So how exactly do you measure the impedance of a big door ......?

[JTUK]

I've had the same cab in 4 and 8 ohms ( 212 config ) and they sounded pretty different...to the point that
I loved the 8ohm version and I've never really been that convinced about the 4 ohms version.. seriously...!!

[r16ktx]

[quote name='Dad3353' timestamp='1416759606' post='2613249']
Pure pedantry, but...

[/quote]
It's not pedantry to want to be precise.

[88reaper88]

[quote name='stevie' timestamp='1416760446' post='2613260']
So how exactly do you measure the impedance of a big door ......?
[/quote]

Depends how fat you are

[r16ktx]

[quote name='88reaper88' timestamp='1416761322' post='2613275']


Depends how fat you are
[/quote]
Ah is this what is meant by a 'fat' sound?

[stevie]

[quote name='JTUK' timestamp='1416760708' post='2613264']
I've had the same cab in 4 and 8 ohms ( 212 config ) and they sounded pretty different...to the point that
I loved the 8ohm version and I've never really been that convinced about the 4 ohms version.. seriously...!!
[/quote]

Actually, the 8 ohm and 4 ohm versions of drivers are often different enough for it to affect the sound. So that makes sense.

[stingrayPete1977]

[quote name='88reaper88' timestamp='1416761322' post='2613275']


Depends how fat you are
[/quote]
I'm about 16 ohms then!

[Bill Fitzmaurice]

[quote name='Dad3353' timestamp='1416756383' post='2613200']
All things being equal elsewhere, the 4 Ohm cab will sound slightly louder.
[/quote]Only at small signal levels. Maximum output is determined by the driver xmax. That's usually the same for 4 or 8 ohms, so maximum output is also the same.

[Dad3353]

OK, so the 4 will sound slightly louder until max, when they will sound equal. Is that better..? [size=4] [/size]

[lowendgalore]

Tonally identical though yeah?

[xgsjx]

I don't get the point of a company making a 4 & 8 ohm version of a 4x10 (or any cab that could be used with another) unless they are tonally different.
When it comes to playing in a band, there's no noticable difference in volume & the 4 ohm cab is only going to make your amp run hotter with no benefits for doing so.

[Bill Fitzmaurice]

[quote name='lowendgalore' timestamp='1416785681' post='2613642']
Tonally identical though yeah?
[/quote]Yes, if the specs are otherwise the same. Sometimes they are, sometimes they aren't.

[Oldman]

For what it is worth:

http://www.speakerimpedance.co.uk/?act=four_parallel&page=calculator

[stevie]

[quote name='Bill Fitzmaurice' timestamp='1416778219' post='2613561']
Only at small signal levels. Maximum output is determined by the driver xmax. That's usually the same for 4 or 8 ohms, so maximum output is also the same.
[/quote]

While this is usually true in practice, it's not always the case. Sometimes maximum output is limited by what the amp is able to deliver, in which case a 4 ohm cab can be very worthwhile.

[JTUK]

I saw the advantage of a 4 ohm 212 at 600w being paired with a 8 ohm 210 at 350w.
I could then run both on a bigger stage without the 210 getting a high load from a 750w delivery.
I heard the 210 bottom out so I made the switch from 8 ohm 212 to 4... so the 4 ohm resistance
would accept and handle the majority of the power. Like a crude cross-over effort, if effect.
Whilst the 212 and 210 works very well..and as intended, the 4 ohms 212 on its own doesn't
work as well for me.
If I only used the 212...I'd want the 8ohm 212 back as I loved that sound from that standalone unit.

[Noisyjon]

[quote name='xgsjx' timestamp='1416786887' post='2613652']
...When it comes to playing in a band, there's no noticable difference in volume & the 4 ohm cab is only going to make your amp run hotter with no benefits for doing so.
[/quote]

The only reason I can think of is if you have a valve amp that only does 2 or 4 Ohm like Ampeg - It at least gives you options and a chance at keeping the cabinetry down a bit!

[xgsjx]

[quote name='JTUK' timestamp='1416826731' post='2613871']
I saw the advantage of a 4 ohm 212 at 600w being paired with a 8 ohm 210 at 350w.
I could then run both on a bigger stage without the 210 getting a high load from a 750w delivery.
I heard the 210 bottom out so I made the switch from 8 ohm 212 to 4... so the 4 ohm resistance
would accept and handle the majority of the power. Like a crude cross-over effort, if effect.
Whilst the 212 and 210 works very well..and as intended, the 4 ohms 212 on its own doesn't
work as well for me.
If I only used the 212...I'd want the 8ohm 212 back as I loved that sound from that standalone unit.
[/quote]
Why not go for two of the 8 ohm 2x12s you like?

[xgsjx]

[quote name='Noisyjon' timestamp='1416831288' post='2613936']
The only reason I can think of is if you have a valve amp that only does 2 or 4 Ohm like Ampeg - It at least gives you options and a chance at keeping the cabinetry down a bit!
[/quote]
That's a good point.