Phase query

In my two way system my mid has a passive low pass filter built into the basket which I believe to be a 6db slope to crossover with the tweeter that came with it at 3khz. I have removed the inline crossover that came with the tweeter and have manually set the highpass on that to 24db LR.

I have a helix dsp with phase control 0 - 360 degrees, electrically speaking what should this be set to on the tweeters so the mid and tweeter are in phase or does it not matter at this freq as long as the freq response looks ok on the rta?

Ok so I think on the helix dsp 270 degrees on the phase slider when the hp is 2db Lw as 90 plus 270 is 360?

You need to acoustically measure the speakers, the setting you actually set in the dsp do not really mean much, other than making sure you are not setting something that is going to destroy your speakers (especially the tweeters!).

So you need to place a microphone at the listening position (acoustically measuring) and play pink noise out of each speaker individually.
Then you need to set a target curve for each speaker. You need to hit that target curve acoustically. So if you want an acoustical crossover at 3000hz and LR 24db, you may not set that electrically in the dsp, it may be 4000hz butterworth 12db slope to get an acoustical 24db LR at 3000hz.

That phase slider is also not doing what you think it is doing to the phase. It is a poor name for it.



This is an example. These are all acoustical moving mic measurements around the Main listening position. The target curves are the pink really smooth looking lines. My goal was what electrical settings in the dsp cause the speakers to hit that target curve. The not so nice lines are the individual speaker measurements.

This will get your phase aligned the best as possible. You may still need some tweaking when multiple speakers are playing TOGETHER, but that would require some all pass filter work, not the phase slider.

https://www.caraudiojunkies.com/atta...5&d=1641329820

Thanks, that makes sense, I will leave the phase slider alone.
I have been using the auto eq feature of the helix and trying the Andy Audiofrog tuning guide but that does the whole of one side + sub the the other side + sub which seemed to result in less bass than when doing the sub separately.

I will have a go at doing each speaker separately and have a look at REW.

When you have done each speaker and then play them all together and there are peaks etc, would it be best to tweak each channel again separately, or is it okay to link the channels in the helix and adjust that way?

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Originally Posted by Crusher

Thanks, that makes sense, I will leave the phase slider alone.
I have been using the auto eq feature of the helix and trying the Andy Audiofrog tuning guide but that does the whole of one side + sub the the other side + sub which seemed to result in less bass than when doing the sub separately.

I will have a go at doing each speaker separately and have a look at REW.

When you have done each speaker and then play them all together and there are peaks etc, would it be best to tweak each channel again separately, or is it okay to link the channels in the helix and adjust that way?

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If you did everything correctly, you should not get a massive peak anywhere. It should look identical to playing all of one side together, only 6db higher.

If you are getting massive peaks/dips, you need to look at what is wrong. Usually that means you have phase alignment issues if you aren't getting roughly 6db increase across the board.