HF Level Contols

[RobertG 16]

 

Guys, I am trying to rebuild my old speakers with new drivers.  I have a question on the HF level control wiring.  The device has three terminals (see Pic). Labeled:  1 no label 2 from left to right.  I believe the no label terminal is the input 1 and 2 are outputs.  So I can control two drivers such as Midrange and tweeter?

 

Thanks for the help!

 

Robert 

[BillD 239]

It is simply a potentiometer.  The three legs are shown in the diagram below.

 

The outer two are usually the horizontal legs and the middle is the wiper.  To get the value of the pot, measure between the outer legs.  To get the direction of the pot measure from the middle to one of the legs as you rotate the wiper.

[RobertG 16]

BILLD,

 

Let me see if I understand.

Using a volt meter,  I measured resistance between the two outer leads.  With the control set to 0,  the reading was zero on the meter, signifying minimum resistance or on maximum output "on full".  Rotating the dial the other direction,   the effect was the opposite or "off to minimum".

 

Connections:  Plan to run the + positive lead through the device.

Middle lead:  Input from crossover

Outer leads:  To Midrange and Tweeter 

Is this correct?

 

Thanks for you expertise! 

 

[BillD 239]

I would have thought that the two outer leads would give you a fixed resistance regardless of where the shaft was turned to.  I think you want to hook up the pot like this:

 

You should have wires coming out of the crossover for the woofer and the rest if it's a 2-way crossover.  I need to understand what this device was doing in the circuit.  Was it attenuating just the woofer, or did it have an effect on the other speakers also?  Do you remember how it was hooked up before you took it apart?  I'm flying blind here.

[RobertG 16]

It was intended to be used to attenuate the Mid and Tweeter horns -   it turned the output level up and down for the mid and tweeter horns.  

It was not connected correctly when I disconnected it unfortunatualy.  

It want to connected it to the Midrange Horn in my new configuration for attenuation level.  

It was connected similar to your diagram.  The 2 terminal was open rather than going to the negative or ground. Terminal 1 was positive lead to the speaker and the center was the input.

 

Does this help? 

[BillD 239]

Well, the lead doesn't need to be grounded (but it should be if you want  to make sure that nothing goes to the attached speaker in the low position).  With it ungrounded, it will never shut off your speaker completely.

[RobertG 16]

Your were right!  It never turned off.

 

I did a bench test wiring like you diagram ant it worked.  Here is my connection diagram.  The level was able to go from max to low to off!  It was missing the ground connection.

Your the best,  and very good at this!

Thanks.... 

 

/yetanotherforum/uploads/20100109160048475.xls 

[RobertG 16]

BILLD,  one more question.  What type of connector is the best to use with lugs on the device in the first note picture.  I was looking for "spade connectors"  that are crimped with a crimping tool.  What is your advice?

[BillD 239]

The very best thing is wire and solder, but if you want to go solderless, get some solderless connectors from Parts Express.

[RobertG 16]

Thanks so much for your help BILLD!

 

 

[RobertG 16]

I completed the project.  The old speakers sound much better now.  Thanks for all the help.

 

Mods:

I replaced some piezzo tweeter horns with soft done type with magnets. Added some JBL high end crossovers.   Connected the HF pot that started this entire topic.