F12 and Sierra2 measurements ?s

[SAFETYpin]

So I'm trying to wrap my brain around as much as I can. I see these same types of posts all over and I've tried to glean what I can from other newbie questions but I can't find "enlightenment".

So, I'm having difficulties understanding all the settings on my F12. Particularly when compared to some of my measurements.

Subwoofer Larger Graph
Round 3 sub settings.jpg
Is 1/3 octave smoothing appropriate while trying to interpret these graphs or is it masking too much detail?

Sub Settings
PEQ=Off
CrossOver is as described in the legend (X50hz or XMax)
Delay/Phase=12oclock (Set without reason)
RumbleFilter=Off
ExtenstionFilter= HI/14hz

AMP Yamaha A-S801
Sub out has a fixed 100hzLPF and no bass management for mains R+L...

Should I turn on the rumble filter to try and tame the bump @ ~17hz?
Which of the Sub measurements looks best for 2.1ch music?
Anything else that stands out as obviously in need of attention?

What does the sub-woofer line in low pass filter do, and how does it relate to the crossover dial? I've measured the difference between all the settings but I don't really understand why or how.

Mains+Sub Larger Graph
Round 3 spl graph.jpg

Should I just be focusing on trying to make the response flat?
Is my sub gain too high? It appears pretty high in the measurements but I don't hear much output from it unless I'm specifically playing bass heavy music.

I assume the rise @ 55hz is room related.

Anyone else have measurements of a well sorted setup to share?

[eyecatcher]

It doesn't look bad at all you did very good. The focus is making the response flat or a little hotter in the sub gain depending on taste from 0 to +3 or +5db.. You don't have an ideal setup control wise because there is no bass management on the mains and a fixed LPF of 100 but your doing okay. The best you can do is crossover where the s2's roll off which would be around 50hz or you will have double bass where their response overlaps each other. Most likely mudding up the mid bass. Just be careful with heavy bass music and high volume because the s2's are running full range since there is no bass management. You will also measure sightly higher distortion in rew in the low octaves due to this. You won't hear the F12 unless it is called upon. It is very clean and mates well with the s2's.

Personally your setup with music I like 14hz/high with rumble off. I would recommend LINE IN and xover dial max for now, and use the LPF fixed 50hz/24 switch filter on the sub amp, then use the phase to smooth out the response near xover. If you want to get fancier there are other settings and ways to adjust like by tweaking the xover dial again. This only works with LINE IN and you'll want to measure with no smoothing but that is usually not necessary to adjust it. You could go with 80hz/24 switch then use the xover dial to bring it down to say 60hz. Most likely the phase will be somewhere between 0 and 90 if it's positioned near the s2's, but it belongs where the response is smoothest near the xover frequency, this will also likely sound the best. Then you can also engage the PEQ to smooth out any bump by toning it down rather than boosting but it doesn't look like you have any major ones at 1/3 octave so I'd leave it off. I wouldn't worry at all about the 17hz, if you wanted to just turn on the rumble filter. I like using 1/12 octave smoothing resolution for fine tuning. You are very close. Good luck sit back and enjoy.

[davef]

So I'm trying to wrap my brain around as much as I can. I see these same types of posts all over and I've tried to glean what I can from other newbie questions but I can't find "enlightenment".

So, I'm having difficulties understanding all the settings on my F12. Particularly when compared to some of my measurements.

Subwoofer Larger Graph
Round 3 sub settings.jpg
Is 1/3 octave smoothing appropriate while trying to interpret these graphs or is it masking too much detail?

Sub Settings
PEQ=Off
CrossOver is as described in the legend (X50hz or XMax)
Delay/Phase=12oclock (Set without reason)
RumbleFilter=Off
ExtenstionFilter= HI/14hz

AMP Yamaha A-S801
Sub out has a fixed 100hzLPF and no bass management for mains R+L...

Should I turn on the rumble filter to try and tame the bump @ ~17hz?
Which of the Sub measurements looks best for 2.1ch music?
Anything else that stands out as obviously in need of attention?

What does the sub-woofer line in low pass filter do, and how does it relate to the crossover dial? I've measured the difference between all the settings but I don't really understand why or how.

Mains+Sub Larger Graph
Round 3 spl graph.jpg

Should I just be focusing on trying to make the response flat?
Is my sub gain too high? It appears pretty high in the measurements but I don't hear much output from it unless I'm specifically playing bass heavy music.

I assume the rise @ 55hz is room related.

Anyone else have measurements of a well sorted setup to share?

this is actually a fantastic in-room response!

[SAFETYpin]

Thanks for the encouragement...! I'm still concerned that the 1/3 octave smoothing is hiding a lot...

Here's the same measurements with 1/12 smoothing, I'll have to remeasure a combined with these specific sub settings.
Bigger Image
Round 3 sub and Main sep.jpg

So if frequency response looks good, next item to consider is RT60 and WaterFall graphs?

[eyecatcher]

I agree with Dave. Your graphs look pretty good and your room acoustics aren't terrible, of course you have great speakers too! I hope you have a calibrated microphone and tripod stand at ear height at the listening position, these help before you get too crazy.

Your looking at the right view to concentrate on. I also like to look at the phase and group delay graphs when dealing with variable tunings and subwoofers in general but thats just me. I'd focus on this one a little more first. The other graphs are cool for seeing the effects of room, treatments or placement but I wouldn't get caught up in those. The data is already collected in these measurements just different ways to look at it to draw interpretations after you take measurements.

You may want to consider changing the axis limits for graphs when tuning by clicking on the limits button. It can be more helpful if you make it vertical 50-110db, it will look more like Ascend graphs and give you a little more detail. The larger axis makes it appear flatter (a trick some speaker mfr's do). Of course you can also change the horizontal frequency limits too if you wanted to focus on say the critical frequency range of the subwoofer blending to midbass from 8hz to 500hz rather than the full frequency spectrum. This will help you fine tune it further. You'll see where the larger peaks and dips are. For instance, you may decide to then get a flatter response you can enable the rumble filter and peq -6db at about 90hz or possibly play the phase.

This is a good baseline. Take good notes of where the settings are before you make changes this way you can go back to the previous if it measures less than ideal. Good luck.

[sludgeogre]

I agree with Dave. Your graphs look pretty good and your room acoustics aren't terrible, of course you have great speakers too! I hope you have a calibrated microphone and tripod stand at ear height at the listening position, these help before you get too crazy.

Your looking at the right view to concentrate on. I also like to look at the phase and group delay graphs when dealing with variable tunings and subwoofers in general but thats just me. I'd focus on this one a little more first. The other graphs are cool for seeing the effects of room, treatments or placement but I wouldn't get caught up in those. The data is already collected in these measurements just different ways to look at it to draw interpretations after you take measurements.

You may want to consider changing the axis limits for graphs when tuning by clicking on the limits button. It can be more helpful if you make it vertical 50-110db, it will look more like Ascend graphs and give you a little more detail. The larger axis makes it appear flatter (a trick some speaker mfr's do). Of course you can also change the horizontal frequency limits too if you wanted to focus on say the critical frequency range of the subwoofer blending to midbass from 8hz to 500hz rather than the full frequency spectrum. This will help you fine tune it further. You'll see where the larger peaks and dips are. For instance, you may decide to then get a flatter response you can enable the rumble filter and peq -6db at about 90hz or possibly play the phase.

This is a good baseline. Take good notes of where the settings are before you make changes this way you can go back to the previous if it measures less than ideal. Good luck.

Excellent comments here. Spot on.

I also think those graphs look really, really good and I'm sure the system sounds fantastic. Good on you for doing such diligent work. I hope to get there some day! Just need to find the time to tweak.

[SAFETYpin]

I hope you have a calibrated microphone and tripod stand at ear height at the listening position, these help before you get too crazy.

I have a MiniDSP UMIK-1 USB mic with the calibration file. I've been placing the mic with the supplied mini mic stand directly on the back of the sofa with the mic pointed forward. I assume this is capturing the listening position?

You may want to consider changing the axis limits for graphs when tuning by clicking on the limits button. It can be more helpful if you make it vertical 50-110db, it will look more like Ascend graphs and give you a little more detail. The larger axis makes it appear flatter (a trick some speaker mfr's do).

5db grads instead of 10db Bigger Image
Round 3 sub and Main sep 5db grad.jpg
Well that changes the picture a bit, I suppose no point in lying to myself about flat straight lines.

I also like to look at the phase and group delay graphs when dealing with variable tunings and subwoofers in general but that's just me.

I'm not sure I understand the phase graph.

I assume I should be trying to adjust my speakers in the room until the Left and Right phases match?

Main Phase Bigger Image
Main Phase.jpg

Bah, more reading and learning... Thanks for the help!!

[eyecatcher]

Yes if the mic is facing forward that would be the 0 degreee correction file. It's best to understand the phase when you measure each speaker individually which your displaying on the phase graph. The phase could be shifted a little since the speakers are possibly not equidistant to the microphone or the room can be effecting it also. Not much you can do to adjust distance in your receiver. But you can see the effect the sound waves have traveling to the microphone where you have a null around 80hz and around 110hz in the full plot and understand it in the phase since one speaker is more positive phase and the other is negative canceling each other out a bit creating the null in the stereo plot. If you look at the individual speaker curves it may help you understand whats going on in the room. Based on the graph most likely somewhere between 90 degree phase on the sub would be best starting point for the flattest overall response with the crossover at 50hz since it would correspond with the sub being "in phase" with respect to the mains.. But you could measure it at 0, 90, 180 to see which yields the overall flattest. Hope this helps.

[SAFETYpin]

But you can see the effect the sound waves have traveling to the microphone where you have a null around 80hz and around 110hz in the full plot and understand it in the phase since one speaker is more positive phase and the other is negative canceling each other out a bit creating the null in the stereo plot.

Well that is interesting...!!! I assume it's due to the right channel not having a wall behind it, while the left is ~19in from the rear wall.... I don't know much about bass port tuning but I assume 80-110hz falls in that range?


http://i.imgur.com/nZvhboU.jpg

I was just going over some of this with someone on reddit they mentioned that the phase measurements are no good with a USB mic, is that correct?

[eyecatcher]

Looks beautiful. I would say it's the room, and the fact that rear firing port could possibly be reflecting off the wall on the left and the right isn't but I would say it doesn't matter too much to loose sleep over it. How does it sound? Are you considering room treatments? Those may help on the wall. You can't do much to fix the timing of anything in your yamaha setup, you'd need external equalization. Something like a MiniDSP. Their FIR filters correct phase shift or something like audyssey. But here is a way to do it for free if you use jriver for streaming https://yabb.jriver.com/interact/ind...?topic=87538.0 The best control you can use to correct timing alignment in your setup is the sub phase control thats the only one you can use to align with the mains.. or moving the speakers/furniture/listening position. Like moving the sub to the right and shift the speakers and entertainment center left?

I found Time-synchronized measurements can be performed with a USB microphone using REW's "acoustic timing reference" feature. To enable it, go to the Analysis tab of the REW Preferences dialog, and in the section labeled Impulse Response Calculation, make sure the Use Acoustic Timing Reference option is chosen before making measurements. This requires REW version 5.15 or later. but if one is using HDMI there are other factors to consider check out http://andyc.diy-audio-engineering.o...ring.html#holm

I would say if you take mulitiple measurements and the phase readings are consistently different then you might not be able to trust them.