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Xilica 4080

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20K views 94 replies 6 participants last post by  jcmusic23 
#1 ·
I have one of these on the way, I am gonna try bi amping my speakers with an active xover. Anyone here use one of these?
 
#2 ·
No direct experience with Xilica products, but just breezing through the literature on their website this unit seems like pretty massive overkill for bi-amping... how many speakers are you attempting to bi-amp?

My guess is that it will work just fine, provided the UI isn't too difficult to deal with. You'll have a thoroughly ludicrous amount of control over each driver and, if it works even half as well as advertised, you should be able to squeeze every last drop of performance available out of your speakers. After you receive it and you've got it all set up, definitely come back and give us your impressions.
 
#4 ·
I had the 3060 and it was a great unit...the only thing I didn't like is the instructions, and tree structure are a learning curve.

Sent from my SM-T550 using Tapatalk
 
#6 ·
Jay,
Given the proper measurements, I can help you establish or confirm the XO settings and the driver delays needed to provide close phase tracking through the XO range. My approach uses IIR (minimum phase) XO filters.
Would you like me to detail the needed measurements?
 
#8 ·
jay,
Per your interest in an optimized design, first let's first investigate the best XO frequency and slopes to achieve an LR-24 acoustic XO. If you have advice on what filter settings to use from other sources we can start with those. Lacking that, I would suggest we investigate a little ourselves. We can skip this preliminary investigation if you care to.

Setup 4080:
> Set XO filters to target value (450 Hz?). [We'll use the value of the passive XO design initially.]
> Set HPF (horn) to LR-12/450 and LPF (woofer) to LR-24/450. [initial guess of the filter slopes needed to approach an LR-24 acoustical XO.]
> If you have already set relative driver SPL levels and PEQ settings for the Khorns it is good to leave those settings active.

Setup REW:
> Neither Loopback Timing nor Acoustical Timing is needed for this analysis.
> Set sweep range 20-20k Hz

Procedure:
> Chose the speaker to measure, right or left.
> Place mic about 1.5 m from the baffle, ~36" above the floor and located on the listening axis (line-of-sight from LP to the mid horn. [This will be roughly 15° off of the speaker's central axis as the speaker is toed-in ~45° and the LP is only toed-in roughly 30°. It's fine to use the speaker axis instead because the impact of this is probably trivial.]
> Measure the woofer response alone.
> Measure the mid-horn/HF horn alone.

Post the mdat of the 2 measurements here. We will be looking to see if the chosen XO filter settings results in driver responses that approach LR-24 filter shapes. We may want to change the filter settings to improve the result if needed.

After we determine the filter settings we can then proceed to set the delay needed.
 
#12 ·
Hi John,
This is absolutely what I wanted to do and thanks for your help. I started putting in settings last night very similar to my current ones, I know we will have to make changes but; I needed a starting point and figured that my current setting are as good as any to start. I will do more tonight and then this weekend will connect everything.
 
#13 ·
Ok John,
I was able to get everything connected and just put in the xovers and the slopes, WOW!!! what a difference. This already sounds better than before and I have not even touched it yet!!! The overall sound is clearer and the bass has much more authority, so I am pretty excited right now and looking forward to measurements and adjustments. As soon as I am able I will get started...
 
#16 ·
Now you see why Danley uses them for their active speakers, and Studios use them.

Sent from my SM-T550 using Tapatalk
 
#19 ·
Jay,
Thanks for the data, but...
Per Post-8 the objective was to see if the XO settings chosen result in a favorable SPL response. Were looking to approach an LR 48 XO response shape in the actual SPL measurement. To do that we need to see the entire XO range. The instruction was to set the measurement sweep to 20-20k Hz for all 3 drivers so we can see the entire response of each driver. The sweeps used were not full range and thus the driver roll-off was truncated. The resulting data is thus not usable for this analysis. [We also must use full range sweeps for the next step also.]
> Loopback timing was applied so that is good. [We will need that for the next step and it creates no problem in this step as we are only looking at SPL response.]
> It appears you placed the mic at a usable distance for this analysis so it appears that instruction was followed.

I suggest we repeat this step
> Confirm the mic positioning.
> Confirm the 4080 XO filter settings. [Again, the LPF for the W should be set to LR-24 and the HPF for the MF horn to LR-12. Similarly set the HPF of the MR Horn to LR-24 and the HPF of the HF horn to LR-12.
> Confirm that you use these settings or provide me the actual XO filter settings you use. I need that information to evaluate if changes are advised.
> Reduce the MR and HF horn levels both about 8db so that the 3 driver SPL levels are more equal (not critical for this step, but it must be done sometime and now is a good time). We can increase the W level instead if you prefer.
> The HF horn needs to have its polarity reversed to follow common practice. We can do that now or later. That can be done with a setting in the 4080 - no need to change the wire connections. There should be an 'invert polarity' setting for each output in the 4080.
> Sweep range must be 20-20k Hz for all 3 sweeps.
> It's better to sweep and save all 3 driver measurements within one mdat file rather than 3 separate files. Please do that unless an HTS file size limit prevents posting. It should be possible to just mute the drivers as needed within the 4080 for each of the 3 sweeps. Label the measurements as; 'W, MR, TW' or similar instead of the date. Just replace the date that REW applies by default.
 
#20 · (Edited)
John,
Sorry about the misunderstanding on my part. So I will make the changes and measure from 20 hz to 20 khz.

Confirm the 4080 XO filter settings. [Again, the LPF for the W should be set to LR-24 and the HPF for the MF horn to LR-12. Similarly set the HPF of the MR Horn to LR-24 and the HPF of the HF horn to LR-12.

John please explain this to me in detail, I am confused by this??? What is MF and MR? I am thinking Mid Frequency and Mid Range?

So you know the LPF is set to LR-24 on the W and the xover is at 400 hz, the HPF is set to LR-12 on the TW and the xover is at 6000 hz, Now what is it you want me to do with MF or MR??? The MD is xover at 400 hz and 6000 hz is this correct? Also you want me to invert the TW correct?
 
#21 ·
Sorry for the confusion. Yes, I inadvertently switched my reference to the midrange horn from MF to MR (mid frequency to midrange). I see that above in post-8 I also used 'mid-horn'. I will try to be more consistent and use 'MR' for 'midrange' in the future.

So for the MR horn: Set the HPF to LR-12 and set the LPF to LR-24.

The logic here is that the 2 horns are likely rolling off their low frequencies near the XO frequency at a But-12 or greater rate without any 4080 XO filter applied. We likely only need a LR-12 (or But-12) HPF to increase that rate so that the total acoustical rate approaches LR-24. After we see what we actually get we can adjust the filter as needed. The closer we get to a symmetrical LR-24 XO the greater the opportunity to get close phase tracking of the drivers throughout the XO range. That will result in a stable frontal lobe and also a more consistent SPL off-axis (in the horizontal plane). These are relatively minor considerations to overall SPL at the LP, but logically provide the best opportunity to achieve a relatively wide and stable sound field at the LP and likely result in more stable imaging and spatial effects.
 
#26 ·
Okay,
First the issues:
> Your mic calibration file does not appear to be very accurate. The overall roughness is too great and the shape also appears to deviate from the expected profile a little too much. I don't think it is bad enough that it will be a major problem though. We normally adjust the house curve a little to taste anyway so it may wash out due to that. I only mention it in case you a highly motivated to achieve high accuracy measurement to work from. A calibration from Cross-Spectrum Labs would provide higher confidence.
> It appears something went wrong in the loopback timing of the HF horn. It was delayed more than the other drivers were. Make sure your loopback cable is connected in channel 1 output to input and that the input level is properly set on that timing channel. I was able to see the evidence of the issues due to the the timing channel crosstalk into the measurement channel. I made the needed adjustment to correct the HF Horn impulse position so the delay analysis below is still good.

Analysis of the XO filter shapes:
> Both acoustic XOs have reasonably good symmetry with these XO filter settings. The lower XO is shaped a little better than the upper one. The roll-off of the HF horn appears to be lower in frequency and shallower than ideal, but it is still very usable. We could confirm the frequency was set correctly and possibly increase the HPF frequency a little and also increase the slope to 18 dB/octave and see it that helps. The phase tracking looks pretty good though so the impact of any changes is not likely to be significant.

Acoustic XOs:
Text Plot Line Diagram Slope


Timing Analysis:
Since the filter settings look reasonable and I was able to correct the misplaced HF Horn Impulse it was possible to go ahead with step 2 to determine the delay adjustment needed for close phase tracking.
> HF Horn: It's the reference so no changes to its delay. Its polarity is also correct now.
> MR Horn: Invert this driver and increase its delay by 0.86 ms.
> W: Invert this driver and leave the delay unchanged.

Phase tracking Lower XO:
Text White Green Line Plot


Phase tracking Upper XO:
Text Line Green Plot Design


EQ Considerations:
With this mic position it is possible to EQ the range above the floor / ceiling bounce frequencies. With the appropriate window settings we can we can safely EQ down to maybe 500 Hz. At this mic distance there is only minor roll-off of high frequencies. In the EQ chart below I did set a very minor slope to the high end reflecting my personal preferences in my setup. You may want to change this as per your preferences. Below 500 Hz it is better to take an average of several measurements around the LP area. It is normally fine to EQ the range below 200 Hz or so to a single LP measurement if you prefer. The mid range from 200-500 is best done with and average measurement and taking care not to be too aggressive. Many prefer to EQ to account for the baffle step effect, but otherwise not use any other EQ in that range. Below I offer a starting point for EQ above 200 Hz as the response needs some EQ to account for the direct sound SPL. The bass EQ must be done from the LP so you can adjust the Woofer level and EQ the response there accordingly. Just with the rough EQ setting I noted below the sound quality is likely to be very good. Both channels should be EQ'ed identically above 500 Hz. Below that you can experiment to see what works best for you. I have had good luck using identical EQ for both channels down to approximately 250 Hz in my setup.

EQ settings:
Text Font Line Number Screenshot


Predicted Response With EQ >500Hz
Text Blue White Line Green
 
#27 ·
Okay,
First the issues:
> Your mic calibration file does not appear to be very accurate. The overall roughness is too great and the shape also appears to deviate from the expected profile a little too much. I don't think it is bad enough that it will be a major problem though. We normally adjust the house curve a little to taste anyway so it may wash out due to that. I only mention it in case you a highly motivated to achieve high accuracy measurement to work from. A calibration from Cross-Spectrum Labs would provide higher confidence.

John that's strange I guess it is a new mic with cal.

> It appears something went wrong in the loopback timing of the HF horn. It was delayed more than the other drivers were. Make sure your loopback cable is connected in channel 1 output to input and that the input level is properly set on that timing channel. I was able to see the evidence of the issues due to the the timing channel crosstalk into the measurement channel. I made the needed adjustment to correct the HF Horn impulse position so the delay analysis below is still good.

Oops, I didn't have the loopback cable connected. Maybe the cause of some bad info?



Analysis of the XO filter shapes:
> Both acoustic XOs have reasonably good symmetry with these XO filter settings. The lower XO is shaped a little better than the upper one. The roll-off of the HF horn appears to be lower in frequency and shallower than ideal, but it is still very usable. We could confirm the frequency was set correctly and possibly increase the HPF frequency a little and also increase the slope to 18 dB/octave and see it that helps. The phase tracking looks pretty good though so the impact of any changes is not likely to be significant.

Acoustic XOs:
View attachment 142370

Timing Analysis:
Since the filter settings look reasonable and I was able to correct the misplaced HF Horn Impulse it was possible to go ahead with step 2 to determine the delay adjustment needed for close phase tracking.
> HF Horn: It's the reference so no changes to its delay. Its polarity is also correct now.
> MR Horn: Invert this driver and increase its delay by 0.86 ms.
> W: Invert this driver and leave the delay unchanged.

I do have some delay already put into the HF and MR horns, is this gonna be a problem?

Phase tracking Lower XO:
View attachment 142378

Phase tracking Upper XO:
View attachment 142386

EQ Considerations:
With this mic position it is possible to EQ the range above the floor / ceiling bounce frequencies. With the appropriate window settings we can we can safely EQ down to maybe 500 Hz. At this mic distance there is only minor roll-off of high frequencies. In the EQ chart below I did set a very minor slope to the high end reflecting my personal preferences in my setup. You may want to change this as per your preferences. Below 500 Hz it is better to take an average of several measurements around the LP area. It is normally fine to EQ the range below 200 Hz or so to a single LP measurement if you prefer. The mid range from 200-500 is best done with and average measurement and taking care not to be too aggressive. Many prefer to EQ to account for the baffle step effect, but otherwise not use any other EQ in that range. Below I offer a starting point for EQ above 200 Hz as the response needs some EQ to account for the direct sound SPL. The bass EQ must be done from the LP so you can adjust the Woofer level and EQ the response there accordingly. Just with the rough EQ setting I noted below the sound quality is likely to be very good. Both channels should be EQ'ed identically above 500 Hz. Below that you can experiment to see what works best for you. I have had good luck using identical EQ for both channels down to approximately 250 Hz in my setup.

EQ settings:
View attachment 142394

Predicted Response With EQ >500Hz
View attachment 142402
I will wait to hear your reply before I change anything.

Jay
 
#30 ·
Yes, make the settings on the other channel the same as this channel. Then place the mic in the correct place for that channel and take the same set of 3 measurements. We just want to confirm the 2 channels are well matched.
> If there are significant differences between channels then we need to resolve that.
> If there are significant differences between the predicted response and the actual measured response then we need to resolve that.
> If all is as expected then this step is complete.
 
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