Time delay/ phase angle calculator

[BigAl205]

Erin posted this in another thread and I thought it might be useful

http://www.sengpielaudio.com/calcula...delayphase.htm

[Hillbilly SQ]

Wow wee that's a lot for my simplistic brain to soak up. It sure did explain some of the strange things I've noticed while tuning over the years. I'll have to spend a few hours on that site when I'm not so tired and need some deep reading to occupy an otherwise boring night.

[erinh]

Check my build thread Chris. I tie some numbers to it and give it a practical feel.

[Hillbilly SQ]

I will Erin, I'll do that and try it in my own rig. You might get asked to do a short lecture about it though at the NC meet...yes I'm thinking about bringing my lead-sled to NC:eek:

[erinh]

I may not make that meet. Work travel.

You should come to finals. All weekend event and a lot closer than NC.

[keep_hope_alive]

this is also a good paper on group delay and phase angles (starting on page 8) that include graphs and images. i know Erin is planning on adding more graphics but in the interim, this can suffice.
http://www.rane.com/pdf/ranenotes/Li...ers_Primer.pdf

[BigAl205]

this is also a good paper on group delay and phase angles (starting on page 8) that include graphs and images. i know Erin is planning on adding more graphics but in the interim, this can suffice.
http://www.rane.com/pdf/ranenotes/Li...ers_Primer.pdf

http://www.caraudiojunkies.com/showt...ley-crossovers

[Hillbilly SQ]

I may not make that meet. Work travel.

You should come to finals. All weekend event and a lot closer than NC.

I've been wanting to go to a NC meet for a couple years now and finally in a place financially where I can pull it off. Timing is everything with these long trips that eat up several hundred dollars. Some people drove twice as far to go to Marv's back when he was doing them. Your meets and the NC meets seem to be getting more and more popular with each passing year.

Back on topic sort of, does delaying the entire front stage several ms in relation to the sub have anything to do with what this thread is about? Jim suggested I try it years ago and it worked for one system, but has seemed to be hit and miss for me the few times I've thought to try it. Right now if I add delay to the sub it gives away its location more and more, but my gut feeling is if I delay my whole front stage equal for each driver it will help push the sub forward of the windshield with the rest of the stage. Depending on what the filter slope is on the sub channel of my pdx5 I could pull the 2x4 that's running the sub out and plug the loc directly into the amp since I don't seem to need any eq at my 75hz crossover point. Probably oughta keep it on the dsp though for ease of tuning changes.

[erinh]

It's all a relative thing. So delaying the entire front or just sub is going to have the same effect.

I know people have been talking about adding a lot of delay to the sub for a long time. But AFAIK no one has ever said why. I'm not breaking ground with my post... I'm just tying the reason to the method. The big delta between sub/mid is required for a large phase shift. And I've found the large phase shift is necessary to really like things up.

For example, I have a phase delay angle of 242deg. That's approximately 9.5 ms delay. My front midbass is delayed about 4.5 ms on average. So the delta between them is 5ms. Or about 126 deg at 70hz.

[Bnlcmbcar]

Is there any logic to this method or was I just lucky?

I used the awesome tracerite calculator from erinh (both the distance and XO settings) for a 3 way setup + sub.

It gave me a large delay for the sub of ~28ms.

The max delay on my Helix DSP Pro is 20.82 seconds which I applied.

But this leaves a difference of ~8ms thats missing.

I then used the linked phase calculator from sengpielaudio to delay the sub channel the extra ~8ms at the sub crossover point. The calculator shot back a phase shift of ~146 degrees which I applied on top of the 20.82ms.

Best sounding upfront bass yet. Luck or logical? Have others tried this method for upfront sub bass?