Rumble combo with 10 inch pa speaker?

[jezzaboy]

File this under stupid question due to being bored.

 

I have a Rumble 500 combo that has a 8 ohms output to another cab to give full power. As I seem to have an abundance of 10 inch pa cabs hanging about, could I connect a active top to the output, will it blow the combo or active speaker? I have to say that I haven`t tried this and dont not recommend trying this until someone with sense comments on this 

[BassmanPaul]

Your question should be can your PA tops handle a bass without being damaged?  Also an active cabinet will not alter the combo's output to 4 ohms. In my mind doing as you suggest will gain you you very little if anything.

 

[ossyrocks]

11 hours ago, jezzaboy said:

File this under stupid question due to being bored.

 

I have a Rumble 500 combo that has a 8 ohms output to another cab to give full power. As I seem to have an abundance of 10 inch pa cabs hanging about, could I connect a active top to the output, will it blow the combo or active speaker? I have to say that I haven`t tried this and dont not recommend trying this until someone with sense comments on this 

Connecting the speaker output of your Rumble to the input of an active speaker is definitely not recommended. You are likely to blow both the output stage of your combo and the preamp of the active speaker. You could run the "LINE OUT" of your Rumble to the active speaker though using an XLR cable, but your combo will still be running though it's own single speaker and seeing total load of 8 ohms.

 

Rob

[Downunderwonder]

Assured destruction.

 

Combo Line Out at least gives a fighting chance for the 10" PA unit to contribute.

 

You would need all four running at low volume to save them from the bass and hear anything useful.

[ossyrocks]

Interestingly, I did recently catch someone just in time, trying to connect the speaker outputs of a powered mixer (1000w) to the line inputs of a house PA system, which were active speakers. I did try to explain the potential results of their actions but they looked at me like I was making a fuss over nothing.

[jezzaboy]

Cool, I had an idea it was a daft thought. Lesson here is don`t post nonsense after being down the pub for a few hours!

[Phil Starr]

I don't think it was a daft thought, it just needs to have a little work done on it. 

 

You can feed a speaker level output into an active speaker but it needs the voltage reduced and some impedance matching. You can buy a DI box which will reduce the signal roughly to a thousandth of the speaker signal and sort all that out for you. In terms of power it would work like adding in an extra Rumble, you'd have the extra power coming from the amp in the active speaker instead of coming from a reduction of the impedance to 4ohms. You'd also have a bit more speaker area radiating sound so you'd get extra volume that way. Though the active might not be as loud as the Rumble depending upon what it is.

 

Connecting the speaker output rather than a line out or FX out from a bass amp means all the tone controls on the Rumble will affect the sound from the active extension. It won't sound like the Rumble though as the combo's speakers are meant to be coloured and the PA speakers to be uncoloured.

 

It might be something to try if you just want a bit more volume but get that matching DI box

[Dan Dare]

2 hours ago, Phil Starr said:

You can feed a speaker level output into an active speaker but it needs the voltage reduced and some impedance matching. You can buy a DI box which will reduce the signal roughly to a thousandth of the speaker signal and sort all that out for you.

 

This is a good solution ,but make sure you use a DI box that has the necessary attenuation (not all do and those which do tend to be more expensive and use high quality transformers, such as Jensen). If you're using a valve amp (not applicable with a Rumble, I know), you need a box that provides a dummy load to to the amp to avoid destroying your output transformer.