real basic question on a Fender cab from a newbie

[XoSo]

Hi Guys,

I know this is probably a very basic question but I'm new to bass and in my previous guitar playing career have only ever had combo amps. A friend has very kindly donated an old Fender 4x10 cab to me - it's a bit of a monster but you don't look gift monsters in the mouth so I accepted it gratefully. I was thinking of maybe getting a little TC BH250 head to go with it (currently using a little vox pathfinder). Now, there is absolutely nothing on the back to tell me what the rating of the cab is other than a little plate that says Fender L082163. It's a closed cab but I suppose I could take the back off it to see what the speakers are. But what's causing me all sorts of newbie confusion is that there are two jack sockets on the back. Does that mean I need to plug two leads in to power all four speakers and what if the amp head only has one input? In your opinions without knowing any more than I've said do you think the cab would be suitable to run a little bass head through it (I'm learning so it will only be for low level practise). Also, at the moment I've got an old HH IC 100S power amp sitting around. It's a guitar amp, but could I get away with using it short term?

[PaulWarning]

I think you're going to have to take the back off, as well as ohms you need to know the wattage it can handle, you don't even know if it's a Bass or Guitar cab, someone else has asked the same question, he thinks it's a guitar cab I think http://www.tdpri.com/threads/what-fender-cab-is-this.290047/
The two jacks are probably in and out for another cab but with the back off you could tell from the wiring

[chris_b]

I don't know about any other Fender cabs, but the current Fender Rumble 410 is (surprisingly) 8 ohms. That's good because if you want to get louder you can just add another cab, but usually 410's are 4 ohms. Your 250 watt amp will only be putting out 125 watts into 8 ohms so I reckon you 'll need to be looking at a 500watt D class amp to get what you need out of this cab, whatever it is.

Most modern D class amps will go into protect mode if you plug the wrong number of cabs in. I would expect that to prevent any damage to the amp if you get it wrong.

[dmccombe7]

If you know an electrician with a multimeter he could check the ohms at the back jack socket.
Otherwise you need to take the back off and look at how they are wired.
Each speaker should have a rating on the back.

Most cabs have 2 sockets at the rear to let you link a 2nd cab.

If your cab is 8ohms and you add another 8ohm cab you'll get 4ohms in total.
With most amps that would increase the output from the amp.
As a very rough guide it would approx double the output.
You probably won't notice an increase in volume to much but you would notice a greater "presence" on stage

Dave

[xgsjx]

[quote name='chris_b' timestamp='1507203163' post='3383868']
I don't know about any other Fender cabs, but the current Fender Rumble 410 is (surprisingly) 8 ohms. That's good because if you want to get louder you can just add another cab, but usually 410's are 4 ohms. Your 250 watt amp will only be putting out 125 watts into 8 ohms so I reckon you 'll need to be looking at a 500watt D class amp to get what you need out of this cab, whatever it is.

Most modern D class amps will go into protect mode if you plug the wrong number of cabs in. I would expect that to prevent any damage to the amp if you get it wrong.
[/quote]
I don't fully agree. You might find that the BG250 will do all you need. Watts don't let you know how loud the thing is going to go.
The more drivers, the more volume. The BG250 would put out a max of 2/3 of the 250 watts, not 1/2 and it's not going to constantly be putting out the max wattage either.
Use your ears, not numbers.
I've no experience of the Fender 4x10 cabs, but DO NOT take 2 leads from the amp to the cab. It's more likely to be to link a 2nd cab. It shouldn't matter which socket you plug in to.

[Bill Fitzmaurice]

Since it's sealed it may be a guitar cab.

[alexclaber]

I'd just plug in and play. As long as it isn't distorting then it'll be fine.

[casapete]

[quote name='chris_b' timestamp='1507203163' post='3383868']
I don't know about any other Fender cabs, but the current Fender Rumble 410 is (surprisingly) 8 ohms. That's good because if you want to get louder you can just add another cab, but usually 410's are 4 ohms. Your 250 watt amp will only be putting out 125 watts into 8 ohms so I reckon you 'll need to be looking at a 500watt D class amp to get what you need out of this cab, whatever it is.

Most modern D class amps will go into protect mode if you plug the wrong number of cabs in. I would expect that to prevent any damage to the amp if you get it wrong.
[/quote]

I've generally found most 4x10's are 8 ohms, certainly slightly older ones.
Newer models often offer a choice of 4 or 8, but as you point out, 8 ohm
versions tend to be more useful / modular.
With newer amps seeming to have more power available too, the benefit of 4 over
8 ohm cabs is getting neglible. IMO of course
Years ago I bought a Peavey 4x10 because it was 4 ohms, quite unusual at the time.
Borrowed an otherwise identical 8 ohm cab one night and really couldn't
detect the difference TBH.

Edited October 6, 2017 by casapete