I have a 3 way crossover at 750, 5000
Using an L-pad on highs and mids
They’re all wired in the same +/- configuration from the crossover
Wondering if the high and mid should be wired the other way round at the driver input or will i blow something up? 🙂 how do i test for polarity?
very new to this so be gentle
Using an L-pad on highs and mids
They’re all wired in the same +/- configuration from the crossover
Wondering if the high and mid should be wired the other way round at the driver input or will i blow something up? 🙂 how do i test for polarity?
very new to this so be gentle
Normally a 3-way 2nd order (12dB) crossover requires the midrange phase to be reversed. The PRV crossover is labelled and that labelling should take the crossover order into account and be correct for normal circumstances, so start by wiring the crossover terminals labeled (+) to the driver terminals labeled (+), etc, i.e. black wires to (-) for all the drivers.
Very occasionally the actual drivers, their placement on the baffle and/or the crossover frequencies will interact in a way that means that this may not hold true, but there is no way to know in advance. If you have an RTA (real time analyser) or FFT (fast Fourier transform) you can check the frequency response across the crossover points. Start with the bass/mid crossover at 750Hz. Measure at about 1 meter to give space for the drivers to sum. If there is a narrow and deep suck-out at 750Hz, try reversing the mid driver. Choose the configuration that minimises the suck-out. Then do the same for the 5000Hz crossover, except this time change the tweeter wiring to get the best result. You don't need a precision RTA / FFT or microphone for this; any old iPhone or Android app will do. The FFT type graph below is idealised, for a 3000Hz crossover; normally it is not quite so clear cut. Red is wrong polarity, green is correct. If you need a noise source for the measurement, the SSSHHHHHH of an FM tuner off station in mono unmuted is good enough to give you the result you need to see.
Very occasionally the actual drivers, their placement on the baffle and/or the crossover frequencies will interact in a way that means that this may not hold true, but there is no way to know in advance. If you have an RTA (real time analyser) or FFT (fast Fourier transform) you can check the frequency response across the crossover points. Start with the bass/mid crossover at 750Hz. Measure at about 1 meter to give space for the drivers to sum. If there is a narrow and deep suck-out at 750Hz, try reversing the mid driver. Choose the configuration that minimises the suck-out. Then do the same for the 5000Hz crossover, except this time change the tweeter wiring to get the best result. You don't need a precision RTA / FFT or microphone for this; any old iPhone or Android app will do. The FFT type graph below is idealised, for a 3000Hz crossover; normally it is not quite so clear cut. Red is wrong polarity, green is correct. If you need a noise source for the measurement, the SSSHHHHHH of an FM tuner off station in mono unmuted is good enough to give you the result you need to see.
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Try it both ways. Hopefully one will sound better. If not then probably you have some more work to do.
Reversing the connections at the mid (or tweeter) terminals will cause no damage, regardless of whether there are L pads or no L pads.
EDIT: I see there is already a facility on your crossover board to alter the degree of attenuation of both tweeter and mid. Are you using additional L pads - variable ones perhaps?
EDIT: I see there is already a facility on your crossover board to alter the degree of attenuation of both tweeter and mid. Are you using additional L pads - variable ones perhaps?
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Thanks, I had edited my post before seeing your response.
I presume you wanted finer control of the attenuation than was offered on the crossover board.
I presume you wanted finer control of the attenuation than was offered on the crossover board.
Correct!
The sound is good but not great… it sounds kinda bite-y and harsh at times. No matter how much I fiddle i can’t get it right.
Midrange actually sounds kinda flat and recessed. Radian 950be’s covering 750-5000hz
Fostex t90a’s 5000hz and above
Box is tuned to about 42hz.. 12” GPA 414 in a 1.5cb ft box
The sound is good but not great… it sounds kinda bite-y and harsh at times. No matter how much I fiddle i can’t get it right.
Midrange actually sounds kinda flat and recessed. Radian 950be’s covering 750-5000hz
Fostex t90a’s 5000hz and above
Box is tuned to about 42hz.. 12” GPA 414 in a 1.5cb ft box
Since you say you're "very new to this", you may not be aware that your off-the-shelf crossover is unlikely to integrate the drivers perfectly.
The favoured approach is to use computer software, such as XSim, to design a custom crossover that better suits the characteristics of the individual drivers.
However, that's a whole new ball game!
EDIT: Correct software type included!
The favoured approach is to use computer software, such as XSim, to design a custom crossover that better suits the characteristics of the individual drivers.
However, that's a whole new ball game!
EDIT: Correct software type included!
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Or you could download a free copy of XSim and have a play around with it.
https://windowsreport.com/best-cros...are solution,... 3 X•over Pro. ... 4 LspCAD.
https://windowsreport.com/best-cros...are solution,... 3 X•over Pro. ... 4 LspCAD.
