Select the Holm 'Device & Signal' tab.
On the top right, under 'Calibrations', select 'Import'. You should be able to then find and select the Cal file on your computer.
There should be a popup that confirms the selection. The box next to 'Microphone' is then checked to show that a Mic cal is active.
On the top right, under 'Calibrations', select 'Import'. You should be able to then find and select the Cal file on your computer.
There should be a popup that confirms the selection. The box next to 'Microphone' is then checked to show that a Mic cal is active.
I dont have much hair left, but holmimpulse is making the rest of it grey...
Using this guide without any luck.
The Subwoofer DIY Page v1.1 - Time Alignment using HolmImpulse
Im trying to time align my 3 way speakersystem.
The Midbashorn is the one farest away, then comes the tweeterhorn
and the closest to listening position is the bass.
Witch speaker should i start with?
If anyone is kind enough to help me i will post screenshots after each step.
Using this guide without any luck.
The Subwoofer DIY Page v1.1 - Time Alignment using HolmImpulse
Im trying to time align my 3 way speakersystem.
The Midbashorn is the one farest away, then comes the tweeterhorn
and the closest to listening position is the bass.
Witch speaker should i start with?
If anyone is kind enough to help me i will post screenshots after each step.
I'm not familiar with setting up car systems, but I would probably measure the tweeter first detect time zero (do it twice, I find Holm doesn't always get it right the first time but the second and subsequent times it does.
Then lock it and measure your midbass. Whether or not it is necessary to do your bass drivers I'm not sure but I would say your midbass and tweeter are the most critical to have in alignment.
Tony.
Then lock it and measure your midbass. Whether or not it is necessary to do your bass drivers I'm not sure but I would say your midbass and tweeter are the most critical to have in alignment.
Tony.
Its not a carstereo, i just thought i could use the guide anyway?
My system looks something like this:
An externally hosted image should be here but it was not working when we last tested it.
Will post screencaps of tweetermeasurement soon!
Settings:
Tweetermeasurement:
Seems ok!? Whats the next step?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Tweetermeasurement:
An externally hosted image should be here but it was not working when we last tested it.
Seems ok!? Whats the next step?
If wintermute does not have the time, or a reference to a detailed procedure for you, I can be available to help you with the process to set the delays between the drivers.
My preferred approach is to set the delays such that there is close phase tracking between the drivers through the entire XO range. This results in the direct sound from the 2 drivers to arrive at the listening position at 'same' time for all the frequencies in the XO range. [If the acoustic SPL roll-off is not symmetrical for the 2 drivers then there will be some deviation from ideal, but the deviation is still minimized and the frontal lobe from the speakers is still very stable.]
With drivers side-by-side and spread so far apart there will be very poor/irregular horizontal dispersion. It is considered better practice to use a vertical driver array. A wide horizontal array means that any offset of the listening position to one side will quickly destroys the timing. Also reflections from side walls are negatively impacted. That said, phase tracking at the listening position of the direct sound is still the method I would suggest.
I can provide next steps if needed.
My preferred approach is to set the delays such that there is close phase tracking between the drivers through the entire XO range. This results in the direct sound from the 2 drivers to arrive at the listening position at 'same' time for all the frequencies in the XO range. [If the acoustic SPL roll-off is not symmetrical for the 2 drivers then there will be some deviation from ideal, but the deviation is still minimized and the frontal lobe from the speakers is still very stable.]
With drivers side-by-side and spread so far apart there will be very poor/irregular horizontal dispersion. It is considered better practice to use a vertical driver array. A wide horizontal array means that any offset of the listening position to one side will quickly destroys the timing. Also reflections from side walls are negatively impacted. That said, phase tracking at the listening position of the direct sound is still the method I would suggest.
I can provide next steps if needed.
Im very happy for all the help i can get 
I agree, me and my brother has just finished building the tweeterhorns so
i have been experimenting with levels and crossovers.
I have to build some proper stands for them as well.
This is an updated picture:
The left channel should look the same soon.
Okey, tell me what to do.
I agree, me and my brother has just finished building the tweeterhorns so
i have been experimenting with levels and crossovers.
I have to build some proper stands for them as well.
This is an updated picture:
An externally hosted image should be here but it was not working when we last tested it.
The left channel should look the same soon.
Okey, tell me what to do.
That should work better.
Let's do just the HF XO on those 2 horns as the example. If needed, I can also help with the other delays as well.
As you did above:
> Mic at the listening positon (orientation is not important for this work)
> I always use the 'log sine sweep' signal, but it probably does not matter which is used. I think the sweep will provide a little more S/N ratio, but again I don't expect a need for that.
> Activate all XO's.
> All measurements should be full range.
> Activate 'Time zero locked'
> Activate 'Keep stream active'
> Select 'Restart stream'
> Measure the HF horn
> Select 'Auto Detect' (a couple times is fine - not critical)
> Copy the 'Offset (Samples)' value and paste it into the 'Locked offset (samples) box.
> Zoom in on the IR as you did above to confirm the IR peak is located near 0ms.
All this should put us back to where you were above.
> Select "measure" again using the same memory location to assure that the IR location is repeated. We should be able to repeat that measurement several times with always the same result. If the IR position changes away from 0ms there is a problem with the time lock and we need to troubleshoot. It is normal that the IR location may change if the stream is restarted so when the IR is stable near 0ms do not restart the stream.
> Measure the MR Horn using a different memory location.
> Save the file.
The rest of the work is done within Holm.
If you post the file I can check to see that all is well and also find the delay change needed.
To do this yourself:
> Turn off SPL traces and turn on only the Phase traces.
> Smooth both traces 1/3 octave.
> Adjust the Offset (delay) of the MR Horn as needed to achieve close phase tracking of the direct sound throughout the XO range. [I expect a very clean phase trace in this case but sometimes, particularly when XO <500Hz, there can be room modes or reflections that make phase chart more difficult to properly interpret.]
> I then reduce the smoothing to 1/6 or 1/9 and sometimes make a minor adjustment to the tracking (delay) when more phase detail is being shown.
> We may find better tracking with the MR horn's polarity reversed.
> Now we have a new value in the MR Horn offset box. The difference in samples between and the new and the original value can be converted to time and that represents the delay change that is needed.
I can provide more detail to this process if needed and will provide the delay change that I think is needed to help you confirm your process.
> I then apply the change in delay (in a DCX2496 in my case) and measure again the 2 horns separately and together to assure that the delay change was applied properly and to see that the SPL reinforcement is good throughout the entire XO range.
Let's do just the HF XO on those 2 horns as the example. If needed, I can also help with the other delays as well.
As you did above:
> Mic at the listening positon (orientation is not important for this work)
> I always use the 'log sine sweep' signal, but it probably does not matter which is used. I think the sweep will provide a little more S/N ratio, but again I don't expect a need for that.
> Activate all XO's.
> All measurements should be full range.
> Activate 'Time zero locked'
> Activate 'Keep stream active'
> Select 'Restart stream'
> Measure the HF horn
> Select 'Auto Detect' (a couple times is fine - not critical)
> Copy the 'Offset (Samples)' value and paste it into the 'Locked offset (samples) box.
> Zoom in on the IR as you did above to confirm the IR peak is located near 0ms.
All this should put us back to where you were above.
> Select "measure" again using the same memory location to assure that the IR location is repeated. We should be able to repeat that measurement several times with always the same result. If the IR position changes away from 0ms there is a problem with the time lock and we need to troubleshoot. It is normal that the IR location may change if the stream is restarted so when the IR is stable near 0ms do not restart the stream.
> Measure the MR Horn using a different memory location.
> Save the file.
The rest of the work is done within Holm.
If you post the file I can check to see that all is well and also find the delay change needed.
To do this yourself:
> Turn off SPL traces and turn on only the Phase traces.
> Smooth both traces 1/3 octave.
> Adjust the Offset (delay) of the MR Horn as needed to achieve close phase tracking of the direct sound throughout the XO range. [I expect a very clean phase trace in this case but sometimes, particularly when XO <500Hz, there can be room modes or reflections that make phase chart more difficult to properly interpret.]
> I then reduce the smoothing to 1/6 or 1/9 and sometimes make a minor adjustment to the tracking (delay) when more phase detail is being shown.
> We may find better tracking with the MR horn's polarity reversed.
> Now we have a new value in the MR Horn offset box. The difference in samples between and the new and the original value can be converted to time and that represents the delay change that is needed.
I can provide more detail to this process if needed and will provide the delay change that I think is needed to help you confirm your process.
> I then apply the change in delay (in a DCX2496 in my case) and measure again the 2 horns separately and together to assure that the delay change was applied properly and to see that the SPL reinforcement is good throughout the entire XO range.
FYI, below is a confirmation of phase tracking for a front right speaker using a IIR 2.2kHz XO (7"MR / 1"Dome). This is the result of a remeasurement after the proper delay was found and applied. The XO range is about 1.2k-5kHz for 25dB suppression. We can see the resulting SPL support throughout the XO range is optimized. The frontal lobe in this range will be stable at all frequecies in this range and the horizontal dispersion is also uniform using a vertical array.
The Holm file you sent has a IR tick mark approximately 15ms before the true measurement IR on both the HF Horn and the MR horn. This should not occur. Do you hear a click sound when you select 'measure' or just before the sweep starts? You may want to investigate this. [There is a similar tick mark before the Bass IR, but the timing is different.]
The 'Offset' value of the bass is set to a different value (26949.792) than the 2 horns (27324.946) so possibly there was some issue with the timing lock? It is more likely that you selected 'Auto Detect' after the measurement was made and that shifted the location the IR to its current location - to the tick mark? After making the measurements all of them should be at the same offset value. The other option is maybe you moved the IR manually to try to align the phase after the measurement, but this is not as likely.
Please advise me your thoughts on this.
The 2 horns IRs are at the same 'offset' value so timing was probably properly locked for those 2 measurements. The tick mark on those 2 does not appear to have interfered with the measurement result so I will find the delay change needed. If you do identify a problem with the timing lock then the results I post will be meaningless.
The 'Offset' value of the bass is set to a different value (26949.792) than the 2 horns (27324.946) so possibly there was some issue with the timing lock? It is more likely that you selected 'Auto Detect' after the measurement was made and that shifted the location the IR to its current location - to the tick mark? After making the measurements all of them should be at the same offset value. The other option is maybe you moved the IR manually to try to align the phase after the measurement, but this is not as likely.
Please advise me your thoughts on this.
The 2 horns IRs are at the same 'offset' value so timing was probably properly locked for those 2 measurements. The tick mark on those 2 does not appear to have interfered with the measurement result so I will find the delay change needed. If you do identify a problem with the timing lock then the results I post will be meaningless.
The Holm file you sent has a IR tick mark approximately 15ms before the true measurement IR on both the HF Horn and the MR horn. This should not occur. Do you hear a click sound when you select 'measure' or just before the sweep starts? You may want to investigate this. [There is a similar tick mark before the Bass IR, but the timing is different.]
I have no idea why that tick occurs?
The 'Offset' value of the bass is set to a different value (26949.792) than the 2 horns (27324.946) so possibly there was some issue with the timing lock? It is more likely that you selected 'Auto Detect' after the measurement was made and that shifted the location the IR to its current location - to the tick mark? After making the measurements all of them should be at the same offset value. The other option is maybe you moved the IR manually to try to align the phase after the measurement, but this is not as likely.
Forgot to tell you, dont mind the bass measurement, it was done earlier.
Please advise me your thoughts on this.
The 2 horns IRs are at the same 'offset' value so timing was probably properly locked for those 2 measurements. The tick mark on those 2 does not appear to have interfered with the measurement result so I will find the delay change needed. If you do identify a problem with the timing lock then the results I post will be meaningless.
I will try to make some new measurements tomorrow, my son is a sleep.
I have no idea why that tick occurs?
The 'Offset' value of the bass is set to a different value (26949.792) than the 2 horns (27324.946) so possibly there was some issue with the timing lock? It is more likely that you selected 'Auto Detect' after the measurement was made and that shifted the location the IR to its current location - to the tick mark? After making the measurements all of them should be at the same offset value. The other option is maybe you moved the IR manually to try to align the phase after the measurement, but this is not as likely.
Forgot to tell you, dont mind the bass measurement, it was done earlier.
Please advise me your thoughts on this.
The 2 horns IRs are at the same 'offset' value so timing was probably properly locked for those 2 measurements. The tick mark on those 2 does not appear to have interfered with the measurement result so I will find the delay change needed. If you do identify a problem with the timing lock then the results I post will be meaningless.
I will try to make some new measurements tomorrow, my son is a sleep.
> I found that the MR horn IR needed to shifted 105 samples and also to have its polarity reversed to best align the phase tracking. The delay change needed is then 105/48000 sample rate = 2.19ms. The MR requires less delay. If the current delays are both at 0ms that means, we can instead increase the delay of the HF Horn by 2.19ms.
Below are 2 charts showing the best timing alignment for the 2 horns.
The SPL chart below shows the the acoustic XO point is near 1kHz. The XO range is approximately 600-1500Hz. After the delay offset of 105 samples was applied, I removed smoothing and used 'manipulation/sum' to calculate the resulting MR horn + HF horn response. This way we can see the SPL support that will occur in the XO range using this delay.
The Phase chart below shows the phase tracking with the 2.19ms delay applied. There are many strong reflections below 1600Hz. As Pano noted, this can make the proper phase much more difficult to determine. This is significantly more hash than I expected with this horn system. In this case I left more smoothing on the HF Horn trace than I would usually use to make the chart more readable. I am sure that this is the correct timing as I have experience differentiating between the direct sound phase and the irregularities due to reflections. Possibly your listening position is near the rear wall or there are just a lot of reflective surfaces. My inclination would be to try to improve this if possible using treatments on first reflective points. Both IR's show a lot of hash trailing the initial IR peak. Many prefer a relatively live room however so it may sound fine just as it is?
I will try to address any questions you have.
Below are 2 charts showing the best timing alignment for the 2 horns.
The SPL chart below shows the the acoustic XO point is near 1kHz. The XO range is approximately 600-1500Hz. After the delay offset of 105 samples was applied, I removed smoothing and used 'manipulation/sum' to calculate the resulting MR horn + HF horn response. This way we can see the SPL support that will occur in the XO range using this delay.
The Phase chart below shows the phase tracking with the 2.19ms delay applied. There are many strong reflections below 1600Hz. As Pano noted, this can make the proper phase much more difficult to determine. This is significantly more hash than I expected with this horn system. In this case I left more smoothing on the HF Horn trace than I would usually use to make the chart more readable. I am sure that this is the correct timing as I have experience differentiating between the direct sound phase and the irregularities due to reflections. Possibly your listening position is near the rear wall or there are just a lot of reflective surfaces. My inclination would be to try to improve this if possible using treatments on first reflective points. Both IR's show a lot of hash trailing the initial IR peak. Many prefer a relatively live room however so it may sound fine just as it is?
I will try to address any questions you have.
Very nice work indeed!
When I was getting confused by reflections measuring at the listening position, I moved the mic closer. To be sure the mic was well placed, I ran a string from the listening position to the center between the drivers. The string line made it easy to stay on the axis I wanted to measure.
One question for Sladbarn. Are you getting consistent offsets when you have locked time? Mine were usually spot on, but different soundcards may not be as good. Just curious.
When I was getting confused by reflections measuring at the listening position, I moved the mic closer. To be sure the mic was well placed, I ran a string from the listening position to the center between the drivers. The string line made it easy to stay on the axis I wanted to measure.
One question for Sladbarn. Are you getting consistent offsets when you have locked time? Mine were usually spot on, but different soundcards may not be as good. Just curious.
Thanks for mentioning this. I do this too if needed. For such large horns I would suggest a minimum distance of maybe 1.5m.