# Xilica 4080



## Jay Compton

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?


----------



## DqMcClain

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.


----------



## Jay Compton

I will do that, a few of my friends are using them and say it's the cat's meow!!!


----------



## NBPk402

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


----------



## Jay Compton

I looked at it last night seems it can be a little daunting but, like anything else you learn as you use it...


----------



## jtalden

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?


----------



## Jay Compton

jtalden said:


> 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?


Hi John,
Yes please give me the first details needed.


----------



## jtalden

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.


----------



## fschris

Jay Compton said:


> 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?


i have a friend using these and his system sounds insane good.


----------



## Jay Compton

As I understand it the sound is amazing using one of these, well I will know soon enough...


----------



## fschris

he is also using those Benchmark ABH2 amps


----------



## Jay Compton

jtalden said:


> 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.


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.


----------



## Jay Compton

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...


----------



## DqMcClain

Jay Compton said:


> 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...


I might need you to do me a favor and NOT rant too much about how amazing it is... I can't afford one right now.


----------



## Jay Compton

Sorry brother the ranting has just begun, i will try and keep it to a roar however. LOL!!!


----------



## NBPk402

Now you see why Danley uses them for their active speakers, and Studios use them.

Sent from my SM-T550 using Tapatalk


----------



## Jay Compton

Yes absolutely!!! I can't wait to really start using it...


----------



## Jay Compton

Ok John,
Back from my trip had a chance today to measure, here are the files..


----------



## jtalden

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.


----------



## Jay Compton

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?


----------



## jtalden

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.


----------



## Jay Compton

Ok John,
Thanks for clearing that up for me, now I understand it. Ok will make the changes and also do you want the TW inverted? I will try and do this tonight.


----------



## jtalden

Yes, we can invert the TW's now. Their polarity will then adhere to the conventional setting. 

In the upcoming timing alignment step we will determine the needed polarity of the MR and W to assure all drivers are working together through the XO ranges.


----------



## Jay Compton

Ok great I will make the changes... Thanks.

Jay


----------



## Jay Compton

Ok John,
I hope I got it correct this time, ok the LPF is 24db on the W, the MR LPF is 24db and the HPF is 12db per your instructions. TW is still 12db. The W is xover at 400hz, the MR xover is from 400hz to 6000hz, TW xover is 6000hz. The TW is inverted to neg. polarity...


----------



## jtalden

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:








*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:








Phase tracking Upper XO:








*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:








Predicted Response With EQ >500Hz


----------



## Jay Compton

jtalden said:


> 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


----------



## jtalden

Jay Compton said:


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


Yes, that is a problem for step-2. Fortunately, at full zoom with the 'normalize' box cleared, we can see the weak crosstalk of the timing channel in the measurements. REW also detected this crosstalk in the timing channel and thus placed 2 of the 3 measurements accurately in time. REW didn't detect the HF Horn timing properly though. It was possible to manually do that however, so the proper positioning was manually restored for this analysis. As a result, this was 'good data' for Step-2 (delay) analysis as well as the intended Step-1 (XO Filter) analysis. This was just a heads-up reminder that for future measurements requiring timing accuracy that the cable must be in place for reliable results. 



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


No, the adjustment is just a change to the current setting so just add 0.86 ms to the current MR Horn delay setting. Leave the delay of the W and HF-horn unchanged. Don't forget to invert the polarity of the W and MR-Horn. I forgot to mention the recommended EQ changes should be applied to the left and right inputs in the 4080, not to the 4080 driver outputs. If you had some EQ already applied you can just add these 4 recommended EQ filters to those current settings.

*Next Action:*
It is now appropriate to remeasure to confirm the results of the changes. To do that just make the recommended changes to delay, polarity and EQ and then remeasure the 3 drivers with loopback timing engaged. I also recommend measuring the other channel with all the same settings, but with the appropriate mic positioning for that channel. When the predicted changes are confirmed by the new measurements and both channels look similar then we are ready for Step-3.

If you post the new left and right channel driver measurements, I can help confirm the Step-2 results.

Step-3 involves moving the mic to the LP for bass EQ adjustment.

Step-4 would involve adjusting the house curve as needed to your preference.

Beyond the 4 EQ filters recommended here as a starting point to confirm the XO settings and provide basic direct sound control, I will leave additional EQ work for your investigation and implementation.


----------



## Jay Compton

Ok John,
That is good news, I will make the changes and re measure and post results. 
Now you are saying that after I make these changes and measure to move on to the right channel and do as I did for the left?

Jay


----------



## jtalden

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.


----------



## Jay Compton

John,
I only had time to do the Left channel tonight sorry, I think I have it all correct have a look. Also I just left everything setup for tomorrow, if I got this correct I will do the Right channel tomorrow during the day.


----------



## jtalden

Thanks for the data.
Well, the measured result does not match the predicted result so there is a problem someplace. The EQ looks good and the drivers polarity is correct per the provided instruction. The delay of the MR horn is not correct however resulting in poor phase tracking and an SPL dip in the XO range. On close examination of the timing crosstalk the 3 drivers reference times do not fall on top of each other as expected. This suggests the REW loopback timing may not be working properly for some reason.

*I suggest: *
> Let's first confirm loopback timing is setup and working properly. Measure the MR Horn 6 times in succession still using the same 20-20k sweep. Post the file so I can confirm the impulse location of each measurement is identical.
> If the measurements do not confirm repeatability, we need to investigate further to determine where the problem is.
> When the repeatability test is successful we can we restart Step-2 delay settings from the beginning. that is, repeat the 3 driver measurements on the left channel to determine new delay recommendations.
> Since we will be starting Step 2 over you can change the mic height as needed to be on your line of sight from the LP to a point on the baffle between the 2 horns. [You indicated to me the 36" height I originally suggested was too low for your high seating position so you can make that height change now.


----------



## Jay Compton

Ok John,
Will have that done a in a few hours.


----------



## Jay Compton

OK John,
Six consecutive times.


----------



## jtalden

I reviewed the data and it looks okay for repeatability. Measurement #4 and #6 deviated very slightly from the other 4. Both may have been due to some ambient room noise during the measurements. I see no major problem with loopback timing repeatability in this data. The MR-horn timing however in the May-31 and Jun-01 measurements is significantly different that lead to this problem. I cannot be sure which timing is correct. Each of the 3 sessions is also slightly different in timing. Possibly that is because windows is locking onto an REW session using a slightly different latency??

The safest path forward is...
> Use one REW session for all the following measurements on the left channel. Nothing should change except the driver selected for measurement.
Measure in the following order: (do not deviate from this order)
> HF-horn
> MR-horn
> W
> HF-horn
> MR-horn
> W
> HF-horn
> MR-horn
> W

That is, measure each of the 3 drivers and then repeat that same series 3 times so there are 9 total measurement in the one file. If the file is then too large to post here you can then break the original file into 2 or 3 smaller files or even email the entire file to me directly. 

This way I can confirm again that the timing is repeatable and if necessary I can also avoid using any odd measurement that appears to be corrupted in time or by noise. I will then provide new driver delay adjustments for the 4080 as needed.


----------



## Jay Compton

Ok John,
I will get started now and have the results soon.


----------



## Jay Compton

Here ya go.


----------



## jtalden

Okay the analysis is complete.
The timing of the MR-horn was wrong. It did agree with the Post-31 so it is consistent with the last set of measurement. I can only conclude that my original analysis in Post-26 was erroneous. 

The adjustment needed is to the MR-horn. It needs a delay increase of 0.58 ms.

The polarities are all correct as measured.

The charts of Post-26 still apply. Below is the overall phase response.








Now we should confirm this analysis.
Measure Left Channel with the new MR delay:
> HF-horn
> MR-horn
> W

Measure Right Channel with the new setting and the appropriate mic position:
> HF-horn
> MR-horn
> W


----------



## Jay Compton

Ok John,
That's good news!!! Now adding the delay of 0.58ms plus the 4.083 that is already in would give me a total delay of4.663 ms correct?


----------



## Jay Compton

John,
I was able to measure the final Left Channel group and then the Right Channel group. Only thing is the Xilica would not give me the 4.663 ms I needed, it gave me 4.666 ms hope that's close enough.


----------



## jtalden

Jay Compton said:


> Ok John,
> That's good news!!! Now adding the delay of 0.58ms plus the 4.083 that is already in would give me a total delay of4.663 ms correct?


Jay,
Probably, but...
Are sure the current setting is 4.083? It sounds wrong based on my experience using the DCX2496. The delay is normally only adjustable to 2 decimal places. Even then the second decimal place usually skips some the numbers due to limitations of a 96000 Hz sample rate. There should be no real need to show 3 decimal places, but Your 4080 box may indeed do that. 

So:
> If it really reads *4.083* then yes we want 4.083 + 0.58 = 4.663 ms [and yes then 4.666 ms is good in that case.]
> If it actually reads *4.83* we want 4.83 + 0.58 = 5.41 ms and thus the data in Post 40 is not usable.

Please reconfirm the actual settings and adjustment are correct before I do the analysis of the data in Post-40.


----------



## Jay Compton

John,
I just sent you an email confirming the numbers.


----------



## jtalden

Thanks, I will analyze the new data.


----------



## Jay Compton

Ok great I'll be waiting for your results...


----------



## jtalden

Good!
This time we hit the exact target of post 26.

The only data adjustment I needed to do was to invert all the drivers in the right channel to match the left channel. Make this change in the 4080.

Below is the resulting comparison of the right and left channels. It appears the level of the Right TW is slightly different from the left so one level could be adjusted so that they match.
















We are done with the confirmation of Step-2.

Your next steps are EQ related so measure the 2 channels individually from the LP in order to EQ the bass range. It is a good idea to average several measurements around the main LP for this purpose particularly if you intend to make any EQ changes above 300 Hz. A window 2' high by 3' wide one reasonable option. You can EQ the 2 channels independently <300 Hz. To the extent the bass is mixed as mono, it may be a better idea to EQ based on the both channels operating together. It is probably situation dependent.
> A good option is to EQ the <300 relatively flat initially. A well setup system may not need any significant bass boost.
> A good option is to leave the EQ unchanged >300 Hz even though at the LP there may be some peaks and dips due to room effects. We have already set a good EQ on the direct sound. 
> There is nothing wrong with trying to adjust >300 if you like for comparison, but changes there should be broad and modest in level.
> You can also experiment with different house curves if the overall balance is not to your preference. 

Let us know how it works out.


----------



## jtalden

I intended to intended the mdat of the 2 channels:

View attachment ja Left and Right.mdat


----------



## Jay Compton

Ok John,
Thanks brother I will adjust the left TW to match the Right TW looks like -1db to me, and then I will setup to measure the speakers separately from the LP...


----------



## Jay Compton

John,
You said earlier to match the polarity of the right channel to the left correct? They were already the matched in the Xilica. The attached file is what happens when I flip the right side to opposite of what they were when you looked at the files.


----------



## jtalden

Is the mic at the LP now? This looks good except...

The woofers are at much higher SPL level relative to the horns when measured here at the LP. They way too high to EQ.

Remember, I had you reduce the MR and HF horns 8 dB in the 4080 in an early post when the mic was close to the speakers. I appears for the LP position we now need to increase the horns back up the about the same 8 dB. Just start there and see how it looks. If necessary adjust again as needed. The objective is to have about the same level from 300-2000 Hz. Once that level is found then you can start work to EQ the <300 range as needed.


----------



## Jay Compton

Ok John,
Agreed they are much louder now then earlier, I will the adjustments...


----------



## Jay Compton

John,
Here are the adjustments made to only the gains.


----------



## jtalden

What happened? 
The 2 channels are opposite polarity of each other now. The polarities were correct in Post-48. Did you change one of the channels?

That's a very big sag/dip from 50-80 Hz. EQ will not be able to help with that. You may want to consider moving the LP position forward or backward to see if it can be improved.


----------



## Jay Compton

John,
Here are the first measurements from today, my notes are attached in the note section. The green trace is the left channel with all drivers in the inverted position. The red trace is the right channel all drivers in the inverted position, the blue trace is the right channel all drivers in the positive position. 

As for the sound, the phantom center sound is present when all drivers from both channels are in the inverted position, when I put all the drivers from the right channel in the positive position I loose the phantom center channel sound.


----------



## jtalden

Jay the good news is that the charts confirm your impression of the phantom center. The channels are in phase when the left channel is negative and the right channel is positive. Below are impulse and phase charts: 
















The bad news is that there is a settings or wiring issue that is causing all the confusion. 

Does the 4080 allow you invert the input channels? If so, one of the 2 inputs may be inverted by mistake. Maybe there is a channel mixing page that has wrong settings. I would look at the 4080 first since that is the new element in your system and I assume you did not previously have this problem.


----------



## Jay Compton

John,
Yes the 4080 allows for changes in polarity on the input side. I thought of that too and checked this what I found, all of the polarity's on the input side are set to positive +...


----------



## Jay Compton

John,
I can't tell you how much I appreciate your help, specially getting this wiring problem fixed!!! I was able to grab a new set of cables today for in the future... Looking forward to our next session maybe Friday or Saturday before I can get back to it.


----------



## Jay Compton

Hey John, 
So I have the new cables and adapter and I am ready to continue, what is the first thing you want me to check?


----------



## jtalden

I suggest...

With:
> Mic at LP
> Loopback timing active
> All 6 of the 2040 outputs set to Negative.

Measure:
> Left channel alone
> Right channel alone
> SWs alone

That will confirm the polarity of the 2 channels now measures correctly with the new cabling and also allow us to determine the best polarity and delay timing for the SWs.


----------



## Jay Compton

Ok John,
Here are the measurements you requested, all the drivers are in the negative position. Left and Right and then the Left and Right subs.


----------



## jtalden

Okay. The phase chart of left and right channels now show the correct phase polarity (per the common convention) and the same phase rotation as it should. If the phantom center is present when you listen this way then finally we have the measurements agreeing with the stage imaging.

With these settings the best timing for the SWs is obtained with the current SW polarity and an increase of the SW delay of 5 ms. [An alternate very good setting is obtained by inverting the current SW polarity and using the current SW delay setting.] 

Both of this options still result is a pretty big sag in the response 50-120 Hz. EQ can help smooth this out, but I suggest you also shift the SW-mains XO point from 50 Hz to 100 Hz so see if that significantly improves the result. To do that, just make the same series of 3 measurements with the XO freq changed to 100 Hz.

Below are the results of the from the current 50 Hz XO setting showing the overall responses with the current SW polarity and +5 ms SW delay.
SPL with SWs:








Phase with SWs:








Phase Tracking through the 50 Hz XO range:


----------



## jtalden

Duplicate Entry


----------



## Jay Compton

John,
Here are the Left and Right Channels with the subs delay of 5ms and the xover at 100 hz.


----------



## jtalden

Okay. That worked out much better.
We need to reduce the SWs delay by 3ms for this new 100 Hz XO setting to achieve the best phase tracking.

With that new setting the following SPL is predicted:

First the left channel. Comparing the alignment of the data from Post-59 (50 Hz) to Post-62 (100 Hz). Note that the SPL support from 55-90 Hz is much better with the 100Hz XO. This is due to the SWs being placed better in the room to avoid that room effect.








Now the right channel. We see the same impact.








The 100 Hz XO will be easier to EQ and result in better bass quality. I would not expect the any downside to this change.

Below is the mdat comparison:
View attachment ja Post 62 Vs Post 59 SPL Result.mdat


----------



## Jay Compton

John,
These are the latest measurements left right with subs and eq according to REW. Let me know if you want to see the subs by themselves. I am going to listen like this for now and see how it sounds, so far it sounds really good.


----------



## jtalden

I'm glad we found a good starting point - one you can enjoy.

> The timing/phase looks good just a predicted. That work was very successful.
> The EQ improved in the flatness in the low bass.
> There is a significant broad increase in SPL from 100-400 Hz. Post-62 data, showed a minorbut more modest. If you added any EQ in that range you may want to check to see if you inadvertently added boost instead cut filters in that range.

The only remaining work is listen and adjust house curve/EQ to determine what sounds best to you given your setup and program material.


----------



## Jay Compton

Hey John,
After looking at the two measurements I see the increase in SPL as you pointed out, funny REW eq called for that boost. so I am going to cut it in half and see where it lands. If you notice in the right chaneel in 59 the REW eq didn't ask for any boost at the same frequency strange...


----------



## jtalden

It's strange that REW would boost a rise further. Possibly the settings chosen lead to that situation. If you want me to take a look, post your mdat file that shows the REW calculated filters that you applied.


----------



## Jay Compton

John,
It was pretty much the same you and I covered when you were showing me how to use the eq function. I have lowered the boost on that filter by half, I will make a measurement in the next couple days hard to do when the wife is home the high frequency's hurt her ears. Then if need be I will post the mdat file of the eq for you to have a look. I played with it some and as you said each time the calculation changes ever so slightly, I just found it strange that it called for the boost on the left channel but not the right???


----------



## Jay Compton

John,
Changing the mic position from up to forward made a big difference, so this is where I am now with the new mic position.
This was using REW's EQ. Sounds pretty good!!!


----------



## jtalden

That looks much better.


----------



## Jay Compton

Ok John,
Great now a little advice please, I listened for a couple hours today and really like the sound. What I noticed was I liked it best around 95db which is a little too much, so is there anything I can do to get the dynamics I get at 95db at a lessor gain?


----------



## jtalden

I have no confidence that I can help. It does not help that I am not sure how to understand '95 dB'. How was that measured? Does it mean you listening above live levels? 
My best guess would be that the frequency response (house curve) does not work well for your preferred; listening level, program material, etc.

The best course of action is to modify the house curve and see what impact it has. It takes time and effort, but that is the only way to satisfy yourself that that you have found the best solution for your situation.

Initially, you may want to try resetting the >300 Hz EQ at ~1m to flat or even slightly up-slope above 2 kHz. We initially set a slightly falling SPL above 2 kHz.


----------



## Jay Compton

Ok John,
Well maybe you are correct about the curve we used but, I like what I am hearing a lot I just have to turn it up to hear and feel the impact. I measured the SPL with my Radio Shack Meter, maybe if I could move the whole spectrum up a few db I could listen at a lessor gain and still have the dynamics and impact I have at 95db?


----------



## jtalden

I also find that it takes near live SPL levels to excite my room and provide a sense of dynamics in the way I prefer. I was guessing that if the highs are rolled off too much it may make it necessary to go even higher in SPL to get that effect. I only know what I have experienced in my room so I don't have any general experience. I would guess that too much absorbent, so very dead room, may have an impact also? Room size may also be a factor? Others with more room acoustics experience are likely to be more helpful.


----------



## Jay Compton

Well I am pretty sure my room isn't dead, it does have four bass traps and two corner traps and two first reflection zone panels' also a 9x12 rug. It still sounds plenty alive to me I just like the impact of the dynamics, so sometime I push the gain up to feel the pressure it creates. It's sounding really good right now so no worries, I will try a few changes down the road but for now I am very happy.


----------



## jtalden

Enjoy the Music. :sn:


----------



## Jay Compton

Yes that is the plan!!!:grin2:


----------



## Jay Compton

jtalden said:


> Enjoy the Music. :sn:


Hey John,
As instructed I have been enjoying the music very much still, I do have a question. About 3-4 months ago I changed the tubes in my pre-amp, these tubes are way more linear than the ones before. Do you think I need to remeasure my room to see if the new tubes changed anything? is that even possible?


----------



## NBPk402

Jay Compton said:


> Hey John,
> As instructed I have been enjoying the music very much still, I do have a question. About 3-4 months ago I changed the tubes in my pre-amp, these tubes are way more linear than the ones before. Do you think I need to remeasure my room to see if the new tubes changed anything? is that even possible?


If it sounds different... I would think it would. Measure different too.Try it out, and let us know.


----------



## Jay Compton

ellisr63 said:


> If it sounds different... I would think it would. Measure different too.Try it out, and let us know.


I am now really sure you are correct, I changed output tubes today and the difference was huge. That tells me for sure I need to remeasure and make setting adjustments, I will post results as soon as I am done...


----------



## Jay Compton

Here are the results from today's measurements, lucky I only had to add one filter to get the results I wanted. Changing the tubes in my pre amp sure made a big difference in the two SPL's. The Reference Level is where I started today and the Tape Deck Level is the finished product, sounds great I am happy with the results. You can go back and look at the original SPL's that i had before the tube change to compare if you like, I think it's post #62.


----------



## jtalden

Jay Compton said:


> ...sounds great I am happy with the results.


That's what counts - good adjustment. 

FYI, The preamp alone could have been measured to directly see the impact of old vs new tubes.


----------



## Jay Compton

jtalden said:


> That's what counts - good adjustment.
> 
> FYI, The preamp alone could have been measured to directly see the impact of old vs new tubes.


Ok John,
How would I go about doing that?


----------



## jtalden

Retain the analog cable from the soundcard output to the preamp input.
Disable phantom power on the soundcard input.
Connect the preamp output to the soundcard input instead of; Xilica/Speakers/Mic. 
Disable the mic correction file.
set a low preamp gain level, check levels in REW and adjust the gain to a test level.
Measure the channel
Repeat using the other preamp channel.

This just confirms the proper response of the preamp using the new tubes and provides a baseline if you later suspect there is a problem, or want to confirm that its time to replace the tubes again.


----------



## Jay Compton

Hi John,
Ok I see where your going with this thanks, the reason for remeasuring was that after I changed the tubes in the pre amp I heard a dramatic difference in sound quality. The new tubes are so much more linear that it was staggering!!! Anyway it was like taking a blanket off the speakers, not that it sounded bad before because it didn't. The new sound is just that much better but it needed a touch of adjustment in the 6khz-10khz range, one filter correctly implemented worked like a charm...
Gonna listen to it this week as is and decide if it's good or needs more, my feeling is i am done!!!


----------



## Jay Compton

Hi John,
Here are the results from today's measurements, hopefully this is what you wanted. Left Channel, Right Channel, then both together, now this is exactly the same as when we finished the work last year only the tube change is different.


----------



## jtalden

Jay,
See the Impulse overlay chart below. The right and left channels have opposite polarity again. We had this problem before and you found the it was a TS rather than a TRS adaptor you were using if I remember correctly. The channels were actually the same polarity but the measuring system inverted the right channel measurement. This may be the problem again?

The "Both" SPL is suppressed and that is also indicative of the same issue.


----------



## Jay Compton

John,
Ok I will check the wires used I may have used the wrong ones but, I thought I through the other ones out so this wouldn't happen again. I will get back to you soon enough thanks brother.

Jay


----------



## Jay Compton

Hey John,
I am using the correct TRS connector, so I must have changed a setting in the interface without realizing. I am sure though that I didn't change anything I guess I messed up when checking the levels, I was having trouble at first. sorr man i need to go through the whole thing again to be sure I have it right. Weird sometime I get this stuff easy but when something goes wrong I am at a loss as to why...


----------



## jtalden

If you have any problem identifying the measurement problem, let us know what soundcard and wiring you are using for the measurements. I have forgotten your situation.

You can also just use the current Left and Right measurements to calculate the "Both" measurement. That will be the most reliable method anyway. If the mic is not centered perfectly using a sweep measurement for "Both", it will result in the high frequency not being shown accurately. 

To combine them in REW first invert the right impulse. Then align the left and right impulses in time. [This 2nd step was not necessary this time as they are already aligned correctly by REW.] Then use REW Arithmetic A + B to get the correct result. The result of that is shown below. I also attached the modified mdat file.









View attachment Post-86ja.mdat


----------



## Jay Compton

Hi John,
I checked in the preferences and found a couple things different than what I remember, I won't know if that was the problem until tomorrow when I setup and measure the room. From the look of what you posted it looks like everything is as it should be? If what you posted is correct to me that looks like where I want to be? As I said it still sounds awesome other than maybe a slight bit hot on the HF end but, that may be due to the source material. Your advice after seeing your result would be to do what? Thanks.


----------



## jtalden

Jay,
The timing/phase rotation looks good - no reason to think there is a problem in that regard.
The SPL response of the 2 channels is very similar so no problems in that regard either.
The SPL of A + B is very similar to my preferred house curve:








There are no significant concerns. If you just want to make a small adjustment to both channels that may be worth a try you could make the EQ adjustment below. I would not think this would be a notable improvement it is just something to try if you are looking for a minor touchup.








Below is the same adjusted response, but using the psy smoothing instead of 1/24 octave. I like to look at the data with various levels of smoothing, but recently have been most influenced by psy smoothing recently.








If you want to address the Hot HF specifically, you can just adjust the house curve accordingly and reset your overall EQ to match. It's really not likely I can suggest effective changes for you. Your own experimentation of with house curve/EQ changes is best route to follow. Good luck!


----------



## Jay Compton

John,
Thanks so much for having a look much appreciated, after reading you post and seeing your earlier work with regard to inverting the right channel in the impulse window I feel like it is real good. I mean to me the channels individually look like what I consider a good match, only did I question it when I looked at both channels together. I am thinking that because the right channel was inverted that threw off that individual response? Once I saw your corrected response I felt like that's what it should be based on the left and right individual responses. I am gonna test some tomorrow to be sure my feeling now is that my TT is in need of a minor adjustment because it is where I am hearing the hot HF. Thanks again.


----------



## Jay Compton

Ok John,
I have tried everything I can think of and nothing I do will change the right channel back to a positive polarity!!! I am exhausted trying to figure this out with no ground gained. I will need your help to figure this out, send me a message and I will call you when you have time.


----------



## jcmusic23

I should have posted this a long time ago, anyway here it is in all it's glory a huge thanks to john for all his help!!!


----------

