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Active, DSP, REW, Xilica 101


rplace

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3 hours ago, Chris A said:

Try adding an additional 1ms delay to the HF channel...

The hypex software only allows about 10 us feet (think that the unit of measurement).  The third one had a inverted polarity with 36 mm of delay or 107 U.S., 

Before adding your recommended delay showing 5k and above at dang near dead Zero.

image.png.e31784b2900c3282a313820ede82c7e7.png

 

 

 

Here is one with adding 10 U.S. or 4 mm with invert checked

image.png.406e37ecdc670e51260d887490003ab5.png 

 

Then un inverting

 

image.png.7ba5334cc717c4182867cc7c3b40e959.png

 

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9 hours ago, rplace said:

If group delay jumps up at that/those same places try inverting phase.

Group delays before Chris's 1 ms recommendation

image.thumb.png.724ab8c152e4eca74bac18a8e8048b78.png

After Chris's recommendation

image.thumb.png.8c97ef9ca11a9d5560d06eec871a938d.png

 

 

 

9 hours ago, rplace said:

I'm no expert but I think #3 is the best if we only consider the three visually

My thoughts as well

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15 hours ago, rplace said:

You need to really zoom in on the group delay. +/-  10ms or less...like 5 maybe. Go back and look at some of my posts. You want everything above 200 to be under 2ms.

Approaching everything one at a time has been very helpful to understand how everyone has dialed in REW.  This all is starting to make a little more since.  Now to figure out the correct equation.  Unfortunately i was hearing some obvious distortion in higher frequencies from one of the drivers.  

 

image.thumb.png.01cd623f0c971328951e08cf2fe9f40e.png

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1 hour ago, rplace said:

Try 1ms of delay to get rid of that sharp cut to the right on the spectrogram at 802.

Dude,

 

If you could move the HF section back (or the LF forward) 13.5 inches relative to each other, that would help to solve your delay problem.  I know that you said that you were out of delay with the FusionAmps, but physical delay of the HF section could help you get there.

 

What are you using in terms of crossover filter order?  If you're using something like 4th order or higher, I'd recommend using first order filters instead.  That will get you most of the needed delay back.

 

What kind of bass bin section are you using that has more than 10 feet of delay at 800 Hz?  That's about double the delay of the K-horn bass bin, and the K-horn bass bin only goes up to ~400 Hz...pushing it, at that.

 

Chris

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Sorry if I miss worded it, but I am not out of delay (at least I don't think I am), I'm just not able to fine tune it to a 1m as it appears hypex only allows 3m increments (I think). I can say the lost I can add is 11 U.S., which I assume is feet. Oh now think of it, I have convert meters/feet to speed of sound as time, is that correct?

Chris, I am using a diy Belle bass bin. I've tried crossover at 1st, 2nd and 4th order at around 420, 450, and I believe 500. I believe it is 2nd order 420 hp and 2nd order 470 lp, but will need to double check.


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I think that my FusionAmp FA122s provided microsecond-level delay adjustment (10 -3 milliseconds), so I think you can just add another 1 ms of delay to what you've got on the HF channels and take another measurement.  The FusionAmp manual says they have 19.2 milliseconds of total delay per channel.

 

Chris

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4 hours ago, The Dude said:

I'm just not able to fine tune it to a 1m as it appears hypex only allows 3m increments (I think).

 

I am not familiar with the Hypex system, so I don't have any helpful advice about that at this time, but it seems that mixing feet, meters, microseconds and milliseconds may lead to some confusion. I would pick just one for all the calculations and settings.

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4 hours ago, Khornukopia said:

At one time here on the forum there was a JuBelle project with a K-510 horn that listed a time delay of 1.9 milliseconds. That could be a good reference point.

The time alignment is one of the more important issues.

There is no reason to guess. HolmImpulse, REW, and other packages (and these are free) will give you a reasonably precise value. Yes, you do need a microphone, but these are not expensive (and certainly worth the investment). In terms of the phase spectrum:  time alignment and a driver wired out of phase are big issues and easily correctible. 

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According to Google 1 MM = 1MS. If so, than 11 U.S. = 3.8 MM or 3.8 MS of delay. I also noted I incorrectly designed my crossover as I was supposed to design it with a q adjustment of .71. This has now been changed as you can see, my shift is further down to the crossover point instead of the 700-800 hz region.

 

Some settings I found along the way for the K402/jubscala settings. Current crossover should be 4th order LR lowpass  at 420, .71 q and Highpass 470, .71q. 

 

image.png.663d6df5bf13298bc4d916d9d9f25c4f.png

41d78dace60bbae6f4fa76cb3cd50ec7.jpg2b4071655a3339eedb8b23e2565fbd14.jpg

 

There is a slight bump between 1k and 1.6k.  

 

image.png.c97de6a8eec056d9f97b43dace3a7f14.pngimage.png.fa3bfa8ba2ce4e535ea7c3487f78d578.png

 

Sent from my SM-G986U using Tapatalk

image.png.33e9b85d944dc47b80b0f0c17857e32a.png

 

 

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Now what should be considered 2nd order with lp at 450 with q of .5 and hp at 450 with q of .5.  There always seems to be that shift around 700-800.  Now knowing that the crossover was 4th order at the 420/470.  I am going to give that a try next.  Chris had mentioned 1st order, is the a Butterworth versus a LR? 

image.png.2196f79c3fababdbc180715b4047647d.png

 

image.thumb.png.724d73ee63e18aa25a90208730d72b95.png

 

 

 

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