crossover question

[jefffluker]

2 way, 4th order LR at 5k. RTA shows a 6db dip centered @ crossover frequency. Possible causes?

[Chris Roemer]

Re: crossover question

Oop?

[billfitzmaurice]

Re: crossover question

2 way, 4th order LR at 5k. RTA shows a 6db dip centered @ crossover frequency. Possible causes?

Try it with reversed polarity.

[DE Focht]

Re: crossover question

2 way, 4th order LR at 5k. RTA shows a 6db dip centered @ crossover frequency. Possible causes?

You may also need to adjust the delay between the two drivers, relative to your listening/measurement position.

Switching polarity may be too coarse of an adjustment to fix the problem.

[1100xxben]

Re: crossover question

You may also need to adjust the delay between the two drivers, relative to your listening/measurement position.

Switching polarity may be too coarse of an adjustment to fix the problem.

I agree. A polarity reversal should have a notch deeper than 6 dB if the time delay between the two is set appropriately.

[billfitzmaurice]

Re: crossover question

I agree. A polarity reversal should have a notch deeper than 6 dB if the time delay between the two is set appropriately.

Operative word: If. The OP hasn't provided sufficient information to determine that. With a combination of time align being off and reversed polarity you could get only a 6dB dip, especially with the minimal bandwidth overlap of 4th order filters.

[1100xxben]

Re: crossover question

Operative word: If. The OP hasn't provided sufficient information to determine that. With a combination of time align being off and reversed polarity you could get only a 6dB dip, especially with the minimal bandwidth overlap of 4th order filters.

I agree, but if he doesn't have time alignment, flipping the polarity won't remedy the problem either. My guess would be that without time alignment, he'll see the ~6 dB dip regardless of the polarity and the frequency will shift around a little.

[billfitzmaurice]

Re: crossover question

I agree, but if he doesn't have time alignment, flipping the polarity won't remedy the problem either. My guess would be that without time alignment, he'll see the ~6 dB dip regardless of the polarity and the frequency will shift around a little.

Perhaps, but since a polarity swap is such an easy process he's got nothing to lose but a few minutes of his time to see what it does.

[jefffluker]

Re: crossover question

Okay, OP here. Everybody chill!

I tried polarity swap. No effect. Tried different x-over frequencies. Little effect. Replaced the hefty Selenium D 405TI with a newer and nimbler PRV neo. BIG difference in the upper midrange (3-4-5k). Thank you all for the suggestions.

[billfitzmaurice]

Re: crossover question

Selenium D 405TI

Shoulda told us that from the get go. The driver data sheet shows that it drops in sensitivity above 2.5kHz..

[jefffluker]

Re: crossover question

True. I should have included driver info in o.p. Thank you all.