finding freq points on active crossover?

[duro78 10+ year member]

first off I don't know why manufactures don't put numbered tick marks around the whole dial, it would avoid a lot of error. Some active crossovers have the low and high freq range say from 30-500 and others will have 4 marked points added to the 10 and 2 o'clock position. Most crossovers I see will go from 30,40,80(2 o'clock) then jump all the way to 500. My original thinking would be there would be equal freq increments from the low to high point. My question is do all crossovers have that drastic jump say 80-500. My crossover only has the low(30) and high(500) is the high slop after the 2 o'clock position standard practice or is it equal increments between 30-500. Might be a dumb question but I don't want to just do it by ear

Click to read more...

 

[audioholic 5,000+ posts]

The reason the xover point jumps so drastically is because of the components used. Put simply, the frequency point does not scale linear with the turning of the knob.

I suspect manufacturers dont bother putting more marks on the knob positions because they realize the unit isn't accurate enough to guarantee the indicated point would correspond with that frequency.

Both of the above mentioned problems only really apply to analog pieces. Digital is where the industry is heading, so I doubt we'll see much/any development in analog units in regards to issues like this.

You can verify crossover settings either by using an rta and a sine sweep, or test tones and a db meter (or your ear).

 

[keep_hope_alive Premium Member]

i think using test tones are the best option (since a test tone CD is much cheaper than an RTA rig).

and linear vs. logarithmic crossover dials depends on the amp. some amps use linear potentiometers so the crossover sweep is linear. but frequency is measured as logarithmic so the point may increase faster as frequency increases. as Audioholic says, measuring the slope after the speaker is preferred since you take all components into consideration, including frequency response and phase interference.

i haven't had to worry about that in my setups for a while. my amps have crossover chips and/or i'm running active with digital controls.

 

[duro78 10+ year member]

thanks for the replies, guess I'll just use test tones and get as close as I can once setting the gains with my dimm