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Jason Foi Studio Design - Tuning
Old 4 weeks ago
  #1
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Jason Foi Studio Design - Tuning

Hello, for those of you who do not know, I have been in the process of converting part of my home's 2 car garage into a small home studio control room. I've finally finished construction and was hoping to get some help with the final tuning of the room.

My original design thread is located here at John Sayer's site: http://johnlsayers.com/phpBB2/viewtopic.php?f=1&t=20552
I have attached a Zip file which contains my SketchUp file for those who would like to download it.




Dimensions: 15.2 Feet (L) x 12 Feet (W) x 8.2 Feet (H)

Monitors: 2x Eve Audio SC208 Flush Mounted and 2x KRK KRK10S Subs.

DSP: MiniDSP DDRC88A-BM with Dirac Live

MIC: UMIK-1 with cal file.

For the attached *.mdat all speakers were playing. I have not yet used Dirac Live or any other DSP other than the onboard crossovers on the 2x KRK10S's (they can not be turned off, but are set to their max 90hz and 180hz) and a -6db low shelf centered at 465hz for baffle step compensation.

I have spent a bit of time measuring and repositioning subs and I think I have found the best possible starting point, but I would like to hear some opinions on my results before I move forward and implement DSP.

Thanks for your help!
Attached Files
File Type: zip JasonFoiStudioDesignModel.zip (6.39 MB, 21 views) File Type: mdat AllTogether.mdat (1.44 MB, 37 views)
Old 3 weeks ago
  #2
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Nice Jason!

ETC and waterfall looks great.

Freq. response could be improved.

Can you play around with your subs? Looks like my old measurements when sub was not properly calibrated. Phase and crossover are your friends here.

About high frequencies: maybe the mic was not on-axis? That would explain that slope above 10khz?


PS: I don't know what I look at in your .mdat file. L & R summed? There is only one measurement.

Last edited by JayPee; 3 weeks ago at 04:52 PM..
Old 3 weeks ago
  #3
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Looks very good to my untrained eyes!

Quote:
Originally Posted by JayPee View Post
Freq. response could be improved.
Well it could be improved, but it's still within +/- 4.5dB, which I think is exceptional!

Waterfall shows some sharp little peaks/resonances at certain frequencies. Could be things vibrating in the room? Doesn’t seem worryingly loud or problematic though (I have a metal radiator that produced very similar results, until I dampened it).

Jason Foi Studio Design - Tuning-waterfall.jpg

Minimum phase plot suggests you might struggle to apply EQ to fix the low end <100Hz (i.e. the excess group delay isn’t flat). But perhaps that can be solved by adjusting the position of your dual subwoofers? Or perhaps it's something that Dirac DSP can in fact cope with (it's able to reduce a 100Hz null in my room, where I also have a minimum phase peak).

Jason Foi Studio Design - Tuning-gd.jpg

Spectrogram shows a 'bloom' in the very low end, similar to my own room. Seems unlikely to be modal, so possibly structural? (i.e. perhaps drywall cavity vibrating). Rest of it looks great; perhaps with something vibrating at around 170Hz.
Jason Foi Studio Design - Tuning-spectro.jpg

Quote:
Originally Posted by JayPee View Post
About high frequencies: maybe the mic was not on-axis?
Either that or L/R comb filtering is causing the drop off at 10kHz. Easy to check with a single speaker measurement.

All things considered, I think you have a truly excellent room here Jason! Great work

Paging Stuart and Akebrake for a more useful/surgical analysis...!
Attached Thumbnails
Jason Foi Studio Design - Tuning-waterfall.jpg   Jason Foi Studio Design - Tuning-gd.jpg   Jason Foi Studio Design - Tuning-spectro.jpg  
Old 3 weeks ago
  #4
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Quote:
Originally Posted by Skol303 View Post
Looks very good to my untrained eyes!


Well it could be improved, but it's still within +/- 4.5dB, which I think is exceptional!
Good yes! exceptional, no, I wouldn't say that. There is room for improvement.

Quote:
Originally Posted by Skol303 View Post
Spectrogram shows a 'bloom' in the very low end, similar to my own room. Seems unlikely to be modal, so possibly structural?
Or sounds/vibrations external to the room.
Maybe your insulation and/or decoupling doesn't go that low. (I haven't checked your thread on JS' forum).

Quote:
Originally Posted by Skol303 View Post
Either that or L/R comb filtering is causing the drop off at 10kHz. Easy to check with a single speaker measurement.
Yes! But I doubt 2 signals are responsible for that slope.

Last edited by JayPee; 3 weeks ago at 04:54 PM..
Old 3 weeks ago
  #5
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I know what design inspired you with your DIY desk...
Old 3 weeks ago
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Quote:
Originally Posted by Northward View Post
I know what design inspired you with your DIY desk...
Lol, i may have seen a similar design in some high end rooms. For my version the sides of the desk are made out of 703 wrapped in fabric and all other open areas are covered in fabric. I already had to change my geometry once i started measuring the FR. The one tiny little flat area on the whole entire desk, the computer keyboard tray, caused a 25db dip at +/-700hz. I built a new top for it angled at 10 degrees and it took care of that. Other than that, it seems to be working well. Plus it just looks freakin cool. It's nice when we can stand on the shoulders of giants to see where we need to go.

Jason Foi Studio Design - Tuning-20180701_225121.jpg
Attached Thumbnails
Jason Foi Studio Design - Tuning-20180701_225121.jpg  
Old 3 weeks ago
  #7
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Quote:
Originally Posted by Jason Foi View Post
Lol, i may have seen a similar design in some high end rooms. For my version the sides of the desk are made out of 703 wrapped in fabric and all other open areas are covered in fabric. I already had to change my geometry once i started measuring the FR. The one tiny little flat area on the whole entire desk, the computer keyboard tray, caused a 25db dip at +/-700hz. I built a new top for it angled at 10 degrees and it took care of that. Other than that, it seems to be working well. Plus it just looks freakin cool. It's nice when we can stand on the shoulders of giants to see where we need to go.

Jason Foi Studio Design - Tuning-20180701_225121.jpg
703 has a fairly high surface impedance. I would not be surprised at all if you'd have better results simply without it.

In short: optimize diffraction over absorption by reducing structural surfaces.
Attached Thumbnails
Jason Foi Studio Design - Tuning-dmp-desk.jpg   Jason Foi Studio Design - Tuning-img_5171s.jpg   Jason Foi Studio Design - Tuning-img_5181s.jpg  
Old 3 weeks ago
  #8
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Quote:
Originally Posted by Northward View Post
703 has a fairly high surface impedance. I would not be surprised at all if you'd have better results simply without.
Does something in my mdat lead you to believe this or is that a more general statement? Since my room is so small i opted for more absorbtion, but if you see something that indicates better performance without the 703, i might remove it.
Old 3 weeks ago
  #9
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Quote:
Originally Posted by Jason Foi View Post
Does something in my mdat lead you to believe this or is that a more general statement? Since my room is so small i opted for more absorbtion, but if you see something that indicates better performance without the 703, i might remove it.
I did not look at your files. It's a general statement based on trials and experiments. 703 in that thickness.is also not an effective absorber. It'll depend on how you planned your room, but the effect would tend to be marginal at best.

Diffraction dictates that if the object is smaller than the wavelength it'll simply wrap around it and it won't affect its phase either. While 703 will reflect a bit due to its surface impedance and affect phase.
Old 3 weeks ago
  #10
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Thomas, what is the effect of these racks when fully loaded? Acoustic wise I mean.
Are the slots still have an effect?

Jason, I'm looking forward to see the development of your room response.

Last edited by JayPee; 3 weeks ago at 09:47 PM..
Old 3 weeks ago
  #11
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Noise

Quote:
Originally Posted by Skol303 View Post
.....All things considered, I think you have a truly excellent room here Jason! Great work

Paging Stuart and Akebrake for a more useful/surgical analysis...!
Agree with Skol303! Nice build and thanks for sharing

RE useful (?) analysis...

The noise floor is quite high and show some strange spikes.
Are there machinery/ fans running?
What will your sound card calibration look like? (feedback?)

Best
Attached Thumbnails
Jason Foi Studio Design - Tuning-noise-floor.jpg  
Old 3 weeks ago
  #12
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Quote:
Originally Posted by JayPee View Post
Nice Jason!

ETC and waterfall looks great.

Freq. response could be improved.

Can you play around with your subs? Looks like my old measurements when sub was not properly calibrated. Phase and crossover are your friends here.

About high frequencies: maybe the mic was not on-axis? That would explain that slope above 10khz?


PS: I don't know what I look at in your .mdat file. L & R summed? There is only one measurement.
Thanks JayPee! Yes, I agree, frequency response needs improvement. I still have to add the minidsp with dirac. I'm just trying to get as good as possible BEFORE I implement DSP.

I have been playing around with sub positions quite a bit. This seems to be the best possible position so far.

Mic is on axis with cal file and measurement was L+R with both subs
Old 3 weeks ago
  #13
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Quote:
Originally Posted by JayPee View Post
Thomas, what is the effect of these racks when fully loaded? Acoustic wise I mean.
Are the slots still have an effect?

Jason, I'm looking forward to see the development of your room response.
Yes, they still work as there is distance between them and the racks: the equipment in it has an effect of its own of course, but the furniture performance in itself isn't affected and frames remain transparent over the audio bandwidth (over 8kHz for the larger frame edges and 12kHz for the slotted areas the furniture starts to function more within a pattern of geometric redirection of sound as the wavelengths become very small and stop diffracting around the slots and frame edges). It's purely down to the rack units, their size, spacing, location etc. As they are the largest objects acoustically speaking.

In short how you lay our the furniture matters a lot too to manage racked equipment reflections.
Old 3 weeks ago
  #14
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Quote:
Originally Posted by Skol303 View Post
Looks very good to my untrained eyes!


Well it could be improved, but it's still within +/- 4.5dB, which I think is exceptional!

Waterfall shows some sharp little peaks/resonances at certain frequencies. Could be things vibrating in the room? Doesn’t seem worryingly loud or problematic though (I have a metal radiator that produced very similar results, until I dampened it).



Minimum phase plot suggests you might struggle to apply EQ to fix the low end <100Hz (i.e. the excess group delay isn’t flat). But perhaps that can be solved by adjusting the position of your dual subwoofers? Or perhaps it's something that Dirac DSP can in fact cope with (it's able to reduce a 100Hz null in my room, where I also have a minimum phase peak).



Spectrogram shows a 'bloom' in the very low end, similar to my own room. Seems unlikely to be modal, so possibly structural? (i.e. perhaps drywall cavity vibrating). Rest of it looks great; perhaps with something vibrating at around 170Hz.



Either that or L/R comb filtering is causing the drop off at 10kHz. Easy to check with a single speaker measurement.

All things considered, I think you have a truly excellent room here Jason! Great work

Paging Stuart and Akebrake for a more useful/surgical analysis...!
Thanks Paul!

The noise floor issue is my PC. I have it in an isolation cabinet i built. I can BARELY hear it in the room, but it does show up rather well in REW. There are also some dimmable track lights that have a bit of a hum too. Unless it proves to be a big problem in the future, I'm avoiding this for the moment as in person it's barely audible.

Any suggestions for sub locations to avoid the minimum phase issue? I assume this is due to differences in distance between subs/mains and LP?
Old 3 weeks ago
  #15
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Quote:
Originally Posted by Jason Foi View Post
Thanks JayPee! Yes, I agree, frequency response needs improvement. I still have to add the minidsp with dirac. I'm just trying to get as good as possible BEFORE I implement DSP.

I have been playing around with sub positions quite a bit. This seems to be the best possible position so far.

Mic is on axis with cal file and measurement was L+R with both subs
L+R - At the same time you mean?

You should only do measurements in mono. One side at a time from sweet spot. Never in stereo. You will not get a usable measurement in stereo.

For speaker calibration 1m away perfectly on axis, and fine match speaker drivers that way using trims in amps. Then check at sweet spot.
Old 3 weeks ago
  #16
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Quote:
Originally Posted by akebrake View Post
Agree with Skol303! Nice build and thanks for sharing

RE useful (?) analysis...

The noise floor is quite high and show some strange spikes.
Are there machinery/ fans running?
What will your sound card calibration look like? (feedback?)

Best
Thanks Ake! Yes, my pc and lights are a bit noisy. I am using a USB UMIK-1 that came with the Minidsp DDRC88A-BM. It didnt want a sound card calibration.
Old 3 weeks ago
  #17
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Quote:
Originally Posted by Northward View Post
L+R - At the same time you mean?

You should only do measurements in mono. One side at a time from sweet spot. Never in stereo. You will not get a usable measurement in stereo.

For speaker calibration 1m away perfectly on axis, and fine match speaker drivers that way using trims in amps. Then check at sweet spot.
Yes the measurement was L and R and both subs at the same time. I'm currently trying to get the flattest LF response possible with what I have at the moment. Once I feel this is the best I can do, then I will start using the MiniDsp to iron out any wrinkles.
Old 3 weeks ago
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Quote:
Originally Posted by Jason Foi View Post
Yes the measurement was L and R and both subs at the same time. I'm currently trying to get the flattest LF response possible with what I have at the moment. Once I feel this is the best I can do, then I will start using the MiniDsp to iron out any wrinkles.
You should redo all your measurements in mono, left then right. First only main, then only subs then main +sub and repost. Stereo file is not very useful.

Use the last one to optimize level and phase relationship between main and sub, still in mono. I would keep the main full range and simply lift and extend the LF using the sub. It's best to try and run the sub only at pretty low frequencies, starting with the crossover between 60 and 80Hz. It's likely you'll need to reverse the phase on the subs using these settings. Locate your subs right under each main against the wall.

For main calibration, measure 1m away on axis and select the flatest speaker - calibrate the other to match it. Speaker calibration is done in 1/3 and 1/6 octave, 1/12 if the room and speakers are particularly flat in response (not in 1/24 or higher as used for room measurements) as it's otherwise basically impossible to visually match the curves - too many variations in the curves to have a clear view of the overall differences.

If there is no dedicated LF trim pot in the amplifier, use the sensitivity knob/trim to first match woofers level. Then use the MF and HF trims to match the rest. Your amplifiers should be remote / removed from the speakers (use extension cables between drivers and amplifiers) as they will heat up and fail quickly if kept in-wall. It's also impossible to calibrate if the amps are still in the speakers cabinets. Usual target is to have the L. Vs R drivers under 0.2dB from each other.

It's not unusual with certain entry level and mid market brands to have pretty wild L/R variations, in the realm of the dB. Higher end brands on the other hand are usually pretty tight from factory and within a couple tenth of a dB. Still worth fine matching though.

I'd avoid DSP, if not possible then use it as an absolute last resort.
Old 3 weeks ago
  #19
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That's my experience as well: using full range on main speakers, the sub (only one in my case) just takes care of the 20hz-50hz or so gave me the best flattest frequency response.

Start flat, but remember you can bump the sub a little bit (bump depends on your taste). Very helpful to have more level in sub region, specially at low level (SPL).

You probably know it, but here is a (classic?) paper by Mr Toole "The Measurement and Calibration of Sound Reproducing Systems":
http://www.aes.org/e-lib/browse.cfm?elib=17839

Worth reading.

Are you happy with your insulation?
Old 3 weeks ago
  #20
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Quote:
Originally Posted by Jason Foi View Post
The noise floor issue is my PC. I have it in an isolation cabinet i built. I can BARELY hear it in the room, but it does show up rather well in REW. There are also some dimmable track lights that have a bit of a hum too. Unless it proves to be a big problem in the future, I'm avoiding this for the moment as in person it's barely audible.
I'd expect hum from a PC/lighting, etc, to be more consistent around just certain frequencies - i.e. resulting in fewer little peaks than seen in your waterfall plot. But I'm only guessing and could be wrong! Your result shows quite a lot of little resonances, which might suggest things are vibrating as well as humming.

Again, this may not be problematic - most of it appears to be very tightly focussed at certain frequencies (high 'Q') and below 40dB, so may not be noticeable. But it may be worth checking whether some of the features in your room are vibrating during frequency sweeps (walls, desk, racks, etc). Stuart advised a simple initial test using fingertips - literally touching surfaces - and it helped me to identify that the drywall in my room vibrates slightly at very low frequencies (30Hz and below), which explains my measurements showing a slow decay down there below the lowest modes in my room (looks very similar to your own results).

I've also found that subwoofer transformer hum can look like a room mode on waterfall plots. I spent a long time trying to tackle a room mode at 50Hz that ended up being my subwoofer So perhaps some of the low-end decay in your room may be caused by a hum from your KRK subs? To determine this, you'll need to run sweep using just your mains and with the subs switched off.

Sorry... not trying to distract you from your core purpose here! Just sharing a few things from my own experience that seem to fit with some of your results.

Quote:
Originally Posted by Northward View Post
Your amplifiers should be remote / removed from the speakers (use extension cables between drivers and amplifiers) as they will heat up and fail quickly if kept in-wall.
So if I understand correctly, you're saying that active speakers aren't suitable for in-wall/soffit mounting? (and passive speakers with an outboard amp are preferred). Never seen that mentioned before, but useful to note!

Quote:
Originally Posted by Northward View Post
It's also impossible to calibrate if the amps are still in the speakers cabinets.
This part I don't understand. Why can't active speakers be accurately matched/calibrated? (e.g. using a separate monitor controller with gain/EQ trim pots).
Old 3 weeks ago
  #21
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Active speakers can be used with flush mounting as long as you allow for ventillation.
Old 3 weeks ago
  #22
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Quote:
Originally Posted by Northward View Post
You should redo all your measurements in mono, left then right. First only main, then only subs then main +sub and repost. Stereo file is not very useful.

Use the last one to optimize level and phase relationship between main and sub, still in mono. I would keep the main full range and simply lift and extend the LF using the sub. It's best to try and run the sub only at pretty low frequencies, starting with the crossover between 60 and 80Hz. It's likely you'll need to reverse the phase on the subs using these settings. Locate your subs right under each main against the wall.

For main calibration, measure 1m away on axis and select the flatest speaker - calibrate the other to match it. Speaker calibration is done in 1/3 and 1/6 octave, 1/12 if the room and speakers are particularly flat in response (not in 1/24 or higher as used for room measurements) as it's otherwise basically impossible to visually match the curves - too many variations in the curves to have a clear view of the overall differences.

If there is no dedicated LF trim pot in the amplifier, use the sensitivity knob/trim to first match woofers level. Then use the MF and HF trims to match the rest. Your amplifiers should be remote / removed from the speakers (use extension cables between drivers and amplifiers) as they will heat up and fail quickly if kept in-wall. It's also impossible to calibrate if the amps are still in the speakers cabinets. Usual target is to have the L. Vs R drivers under 0.2dB from each other.

It's not unusual with certain entry level and mid market brands to have pretty wild L/R variations, in the realm of the dB. Higher end brands on the other hand are usually pretty tight from factory and within a couple tenth of a dB. Still worth fine matching though.

I'd avoid DSP, if not possible then use it as an absolute last resort.
Ok, i'll give all of this a shot and post the results. Luckily i can access all of the trim and filter settings from the front of the monitor. Is there really no advantage to using different sub positions? I was interested in Geddes work and the results shown here https://www.andyc.diy-audio-engineer...tml/index.html but i'm inclined to trust your experience. What are advantages and disadvantages of both methods? Purely phase issues with multiple locations?
Old 3 weeks ago
  #23
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Quote:
Originally Posted by Skol303 View Post
So if I understand correctly, you're saying that active speakers aren't suitable for in-wall/soffit mounting? (and passive speakers with an outboard amp are preferred). Never seen that mentioned before, but useful to note!

This part I don't understand. Why can't active speakers be accurately matched/calibrated? (e.g. using a separate monitor controller with gain/EQ trim pots).
That's not what I'm saying. What I'm saying is that you can't leave the amps in the cabinets as they will overheat and fail. In a proper in-wall design they simply cannot cool down, there is zero air flow in there. So they need to be removed and placed remote in a dedicated rack or panel that also allows easy access to settings - which means extension cables etc. With remote amps they are still active speakers. I'm not fond of passive speakers.

On the second point, calibration means access to electronics for very fine and repeated adjustments - the trims are usually very sensitive when dealing in 0.1dB increments. These trims are usually on the amp PCB itself, very seldom accessible from amp main panel. In either cases not removing the amps from cabinets would mean you'd literally spend hours constantly moving the speakers in and out of the wall and then removing amp from cabinet to get access, put speakers back in wall, lock them in again, measure again, rince and repeat many times around. Which is a complete waste of time and includes high risks of hitting/moving the measurement mic stand and creating damage to the front wall and/or cabinets.

All in all there are no good reasons to keep the amps in the cabinets. It reduces their lifespan and performance substantially, and is very unpractical.

It's easy to DIY extension cables.
Old 3 weeks ago
  #24
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Quote:
Originally Posted by Jason Foi View Post
Ok, i'll give all of this a shot and post the results. Luckily i can access all of the trim and filter settings from the front of the monitor. Is there really no advantage to using different sub positions? I was interested in Geddes work and the results shown here https://www.andyc.diy-audio-engineer...tml/index.html but i'm inclined to trust your experience. What are advantages and disadvantages of both methods? Purely phase issues with multiple locations?
What you want is to get as close to a point source as possible. Geddes is a band aid solution to a room with what would qualify as a pretty bad LF response - in your case you can work on the room response so that you don't need a band aid solution. And can go for a much better scenario: as close to a point source as possible. Putting them under the mains will get them as close as practical from the mains and create a corner loading scenario, allowing to get a given SPL using less power and hence lower distortion. They are much closer to proper time alignment too (with no need for DSP).

Stereo subs set this way also load the front wall in quasi minimum phase (no SBIR) and load the room efficiently in terms of LF dispersion.
Old 3 weeks ago
  #25
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Quote:
Originally Posted by Northward View Post
What you want is to get as close to a point source as possible. Geddes is a band aid solution to a room with what would qualify as a pretty bad LF response - in your case you can work on the room response so that you don't need a band aid solution. And can go for a much better scenario: as close to a point source as possible. Putting them under the mains will get them as close as practical from the mains and create a corner loading scenario, allowing to get a given SPL using less power and hence lower distortion. They are much closer to proper time alignment too (with no need for DSP).

Stereo subs set this way also load the front wall in quasi minimum phase (no SBIR) and load the room efficiently in terms of LF dispersion.
Is it better to give each sub their appropriate channel (L/R) or send each sub a summed (L+R) channel?
Old 3 weeks ago
  #26
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Quote:
Originally Posted by Jason Foi View Post
Is it better to give each sub their appropriate channel (L/R) or send each sub a summed (L+R) channel?
Each their channel L/R.
Old 3 weeks ago
  #27
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Quote:
Originally Posted by Northward View Post
Putting them under the mains will get them as close as practical from the mains and create a corner loading scenario, allowing to get a given SPL using less power and hence lower distortion. They are much closer to proper time alignment too (with no need for DSP).

Stereo subs set this way also load the front wall in quasi minimum phase (no SBIR) and load the room efficiently in terms of LF dispersion.
One sub directly under each monitor, like say 2 feet or less for example ? And are they aiming in the same directions as the mains ? Similar to the layout of most club PAs ?

Also, you are suggesting to not use a crossover setting that removes some of the lows from the mains, but instead just to use some type of LPF on the subs and leave the mains untouched ?

Thanks for your input.
Old 3 weeks ago
  #28
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Quote:
Originally Posted by Northward View Post
In a proper in-wall design they simply cannot cool down, there is zero air flow in there. So they need to be removed and placed remote in a dedicated rack or panel that also allows easy access to settings - which means extension cables etc. With remote amps they are still active speakers. I'm not fond of passive speakers.
Thanks for clarifying

My own active speakers are set up on stands (pushed up against the front wall), but I’ve considered moving them in-wall in future. I’ll keep your advice in mind when the time comes.

As for calibration, the monitor controller I use (Drawmer) allows for very fine adjustments - certainly within 0.1dB if used carefully - but it does take some time and patience to get L/R correctly balanced. I use frequency sweeps at 1/3 and 1/1 smoothing to compare and adjust each speaker until they match as closely as possible.
Old 3 weeks ago
  #29
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Quote:
Originally Posted by sage691 View Post
One sub directly under each monitor, like say 2 feet or less for example ? And are they aiming in the same directions as the mains ? Similar to the layout of most club PAs ?

Also, you are suggesting to not use a crossover setting that removes some of the lows from the mains, but instead just to use some type of LPF on the subs and leave the mains untouched ?

Thanks for your input.
Yes, try and locate your L and R sub right under the mains, on the same vertical axis. It will work with in-wall and quasi flush mount.

Correct for the mains: just leave them full range. Use the built in LPF of the subs set fairly low (under 80Hz usually) and just augment/expand the response of mains to taste.

If you're not using mains (as in full range or sufficiently full range speakers ) this may not necessarily work well for a number of reasons (type of port tuning, cut off slope etc) but it's usually worth trying anyway.
Old 3 weeks ago
  #30
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Quote:
Originally Posted by Skol303 View Post
As for calibration, the monitor controller I use (Drawmer) allows for very fine adjustments - certainly within 0.1dB if used carefully - but it does take some time and patience to get L/R correctly balanced. I use frequency sweeps at 1/3 and 1/1 smoothing to compare and adjust each speaker until they match as closely as possible.

But It does so for the whole bandwidth, not per driver, which is a pretty big limitation. Sometimes the midrange is well aligned, but not the tweeters or the woofers - basically any combination of this may happen. So you just lose somewhere to gain somewhere else by averaging over the whole response bandwidth using a level trim on your monitor.

To calibrate, bypass the monitoring section. Go from a good D/A straight to amps and use the same D/A output channel to calibrate so the source is absolutely the same. Select the flatest speaker and calibrate the other to match it.

Calibrate driver per driver until they individually match, which you can only do by accessing the trims in the amplifiers.

Monitor section output must also be calibrated separately, usually using test equipment like an AP (like a 5xxx series) or a Lindos MS-20 (I was recommended the Lindos by a tech I really trust and it's a great tool for everyday studio maintenance, love that thing!).

Last edited by Northward; 3 weeks ago at 10:37 AM.. Reason: Spelling
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