4 ohm head into a 8 ohm cab

[Jordy4strings]

Will this be ok? If the head is 500 watts and the cab is 300 watts, how much output am I looking at? Will
I get 300 watt output max? Or is it impossible because its only 8ohm? Kr

 

[ctmullins]

Hi Jordy,

All bass heads are designed to run at more than one impedance. Solid state heads have a minimum impedance, and anything more than that is okay. Tube heads typically have separate output jacks for each impedance.

If you hook up an 8 ohm cab to a solid state head, it will operate at 8 ohms. And while the wattage will usually be lower than the 4 ohm output, it will still work just fine. The difference between 8 ohms and 4 ohms is only 3dB (all else equal), and 3dB is not very much.

As I mentioned in your other thread, don’t think in terms of Watts. Watts are mostly marketing. Think in terms of impedance and deciBels.

 

[Low Class]

Will this be ok? If the head is 500 watts and the cab is 300 watts, how much output am I looking at? Will
I get 300 watt output max? Or is it impossible because its only 8ohm? Kr

Yes it is ok. Your head will be producing around 300 watts. You can also hook up another 8 ohm cab which will give it a 4 ohm load.

 

[Scottgun]

I let others talk about the wattage, but the news is you won't overwork the rig, potentially damaging it. The bad news is the rig will sound dull, which will tempt you to start turning knobs to a risky level.

 

[Low Class]

I let others talk about the wattage, but the news is you won't overwork the rig, potentially damaging it. The bad news is the rig will sound dull, which will tempt you to start turning knobs to a risky level.

I'd like to know how you came about that without even knowing what amp or cab he's even talking about.

 

[Jordy4strings]

Hi Jordy,

All bass heads are designed to run at more than one impedance. Solid state heads have a minimum impedance, and anything more than that is okay. Tube heads typically have separate output jacks for each impedance.

If you hook up an 8 ohm cab to a solid state head, it will operate at 8 ohms. And while the wattage will usually be lower than the 4 ohm output, it will still work just fine. The difference between 8 ohms and 4 ohms is only 3dB (all else equal), and 3dB is not very much.

As I mentioned in your other thread, don’t think in terms of Watts. Watts are mostly marketing. Think in terms of impedance and deciBels.

If the amp is working now at 8ohms will that decrease its output from 500 to 250 watt? Or can I still get the full 300 watt from the cab? Cheers

 

[Low Class]

If the amp is working now at 8ohms will that decrease its output from 500 to 250 watt? Or can I still get the full 300 watt from the cab? Cheers

What amp are you talking about? You won't hear much difference between 250 and 300 watts...and you're not getting 300 watts from the cab, you're getting it from the amp.

 

[Jordy4strings]

Yes it is ok. Your head will be producing around 300 watts. You also hook up another 8 ohm cab which will give it a 4 ohm load.

Hi, is 300 watts enough to play small gigs with a guitarist and drummer? Its quite a loud rock band. Thanks

 

[Jordy4strings]

What amp are you talking about? You won't hear much difference between 250 and 300 watts.

tc electronic bq 500. Im on a budget and cant afford to spend 1000 pounds.

 

[Low Class]

It's probably 250, but I wouldn't sweat over it.

 

[Low Class]

Hi, is 300 watts enough to play small gigs with a guitarist and drummer? Its quite a loud rock band. Thanks

Depends on your cab(s).

 

[ctmullins]

Hi, is 300 watts enough to play small gigs with a guitarist and drummer? Its quite a loud rock band. Thanks

Stop thinking in Watts. You can make a lot of deciBels if you pair that amp with the right cab. Look for one with multiple drivers and high sensitivity.

 

[Jordy4strings]

Stop thinking in Watts. You can make a lot of deciBels if you pair that amp with the right cab. Look for

Stop thinking in Watts. You can make a lot of deciBels if you pair that amp with the right cab. Look for one with multiple drivers and high sensitivity.

Thanks ct. can you recommend a good cab?

 

[Jordy4strings]

Depends on your cab(s).

Probably a stupid question but if you add another 8 ohm cab into the mix, will it give twice the output? If output of head is 500watts and you get 300 watt output from 1 cab, will you get 600 watts in total from 2 cabs?

 

[ctmullins]

Thanks ct. can you recommend a good cab?

Not really. I build my own using Eminence neo drivers. And what’s available to you depends on where you live.

 

[Jordy4strings]

Not really. I build my own using Eminence neo drivers. And what’s available to you depends on where you live.

Ok. One more silly question. If the head is 500 watts at 8ohm and the cab is same watt and ohm, can I get 1000 watts by hooking up 2 cabs?

 

[ctmullins]

Ok. One more silly question. If the head is 500 watts at 8ohm and the can is same watt and ohm, can I get 1000 watts by hooking up 2 cabs?

Generally, for solid state amps, the output power at 4 ohms is almost double the power at 8 ohms. So if your amp does 500 Watts at 8 ohms it will probably do around 900 Watts at 4 ohms. There are exceptions; it depends on how the amp was designed.

Using two identical 8 ohm cabs for a 4 ohm load is a smart approach (and common, because we are all pretty smart ). This lets you “get the most Watts” from a solid state amp, but the real benefit is doubling the number of drivers. You can also just take one cab for smaller gigs.

 

[JimChjones]

Further to good points above:

The power rating of an amplifier is how much power it delivers into the speaker system at a given level of distortion. If the amplifier is driven hard into high levels of distortion it may produce rather more power than that, but it won't be great sounding power and if you have tweeters in your cabinet you will be doing them no good at all.

The power rating of a speaker cabinet is how much power may be sent to it without too much risk of serious damage.

The actual volume delivered by the net rig is a combination of both the power going into the cabinet and its efficiency, which will vary considerably, but a good rule of thumb is the more the area of the speaker cones the greater the volume.

Provided you've got 4 10in drivers, 2 15s or the equivalent the vaguely 250W your amp ought to deliver into 8ohms should be enough for anything but the keenest seekers of tinnitus.

 

[Low Class]

You still haven't told us what cabs you're looking at! A 1x10" is whole lot different than a 4x10" regardless of ohms or watts..

 

[Jordy4strings]

You still haven't told us what cabs you're looking at! A 1x10" is whole lot different than a 4x10" regardless of ohms or watts..

Warwick WCA 115 Light Weight Cab – Thomann UK