Passive crossover with tube amps?

[moltenmetalburn]

Can i use a passive crossover in my guitar cabinet ?

Any reason it's bad for the tube amp?

Advice, contraindications?

 

[srinivassa]

Weird. I was just thinking this for the first time. To get more low end without bombing my higher end speakers with bass. Like a crossover between a Classic Lead 80 and a Swamp Thang. Pick 2000 Hz or so.

Seems like it should work, but there's probably a reason people don't do it.

 

[jkdsteve]

I suppose the general reason people don't do it is there's not supposed to be much happening from the guitar in those frequencies.. :shrug:

 

[moltenmetalburn]

I suppose the general reason people don't do it is there's not supposed to be much happening from the guitar in those frequencies.. :shrug:

Not sure what you mean. I would choose the crossover point based on guitar frequencies. Probably around 300 hz or so.

Thinking about using a favorite twelve inch for the high and a 15 inch guitar or bass or two bass 10 inch for the lows.

 

[Sixtonoize]

As long as you do the calculations and make sure that your frequencies and impedances are where you need them to be, it shouldn't be a problem.

 

[moltenmetalburn]

As long as you do the calculations and make sure that your frequencies and impedances are where you need them to be, it shouldn't be a problem.

Could you be more specific relating to the impedance considerations?

 

[srinivassa]

You might have a hard time finding a 2-way crossover with that kind of frequency range. Maybe you could make use of a high-pass somehow? Can you corral an 800 Hz high pass into acting like a 2-way xover?

I think the impedance concerns are to protect your output transformer on your amp. You have to make sure it sees a fairly uniform impedance that doesn't dip when the frequency component of the signal changes.

 

[wolfeman28]

I built one a while back. I thought it would be great for using when micing a cab.

It doesn't make a huge difference, but I like what it does.

As you can see from the graph, it affected the lower mids more than I would have liked it to, but as it turns out that works good with a V30 and an SM57.

With a bit more time and effort, you could probably get the roll off to start at a different point.

 

[moltenmetalburn]

I built one a while back. I thought it would be great for using when micing a cab.

It doesn't make a huge difference, but I like what it does.

As you can see from the graph, it affected the lower mids more than I would have liked it to, but as it turns out that works good with a V30 and an SM57.

With a bit more time and effort, you could probably get the roll off to start at a different point.

Very cool. I was thinking about using a choke as an inductor.

 

[wolfeman28]

You can get all the parts from here, and use this as a calculator to figure out what you need.

Remember, just because your amp says it's a certain ohm output(8 ohms will never be exactly 8 ohms), it will most likely be off by quite a bit and that will affect your crossover.