setting impedance

[Tachy]

I have a Marshall cab and I can connect my head in 3 different modes:
1 ) set the cab in mono 16 Ohm, 16 Ohm in the head
2 ) stero with 2 cables ( 8 Ohm ) and set the impedance in a head at 4 ohms
3 ) connect the cab at 4 Ohm in mono-4 in the head

My head have parallel outputs.

What is for you the best mode?

I hear people that connect the cab with the impedance in this mode :
8 Ohm in the head and 16 in the cab..only in mono mode.

 

[Niels]

I have a Marshall cab and I can connect my head in 3 different modes:
1 ) set the cab in mono 16 Ohm, 16 Ohm in the head
2 ) stero with 2 cables ( 8 Ohm ) and set the impedance in a head at 4 ohms
3 ) connect the cab at 4 Ohm in mono-4 in the head

My head have parallel outputs.

What is for you the best mode?

I hear people that connect the cab with the impedance in this mode :
8 Ohm in the head and 16 in the cab..only in mono mode.

I also tried out the 3(4) possibilities you mentioned above and I think it doesn't make a big difference which one you choose. What amp do you use, Marshall? I think you get the best results by using the same impedance on amp and box - because you don't have a lack of power then. If you switch the amp's impedance lower than the impedance of the box, the amp needs more power to push the speakers than 'expected'. For example: amp switched to 8 Ohm and Box to 16 Ohm, the amp 'expects' an impedance(resistance) of 8 Ohm but has to deliver the same power to 16 Ohm.

One thing that could make a difference would be using amp and box in stereo, both with 8 Ohm. Assuming you use a Marshall JCM 900 or something comparable: The 100 W modells got one pair of tubes for each speaker output(50 W for one output!) - if you use it stereo you should have some more power in reserve, especially at high volume.

But imo the differences are not that big!

One more thing: never ever switch the impedance of your box lower than the impedance of your amp! Sooner or later this kills every (tube) amp!!!

Rock on!

Niels

 

[Tachy]

Originally posted by Niels

One more thing: never ever switch the impedance of your box lower than the impedance of your amp! Sooner or later this kills every (tube) amp!!!

Yes I know that, ok..thanks !