just did my first room measurements with REW using a MiniDSP UMIK-1. I took six measurements, two at the centre position corresponding to my listening position and one measurement 20 and 40 cm off axis to the left and to the right.
I overlaid all six measurements and smoothed them (var smoothing).
I hope I interpret the plots correctly: there’s quite a bass mode at 37.5 Hz common in all measurements, and another mode, although not common in all positions, at around 91 Hz.
After reading a lot in this forum, the 37.5 Hz mode needs to be corrected. REW suggests dampening with about -11 dB and a Q around 12. I think this is reasonable. I read in many room EQ forums that dips can’t be reasonably handled, so I first want to target the 37.5 Hz hump, eventually also the 91 Hz peak. Therefore, I don’t really want to export EQ to a wav file and load it into Roon’s DSP panel. Rather I’d like to manually target the room modes with the Parametric EQ tab. Roon however, accepts Q values of up to 10. Is this a different scale Roon uses, or is it just the algorithm’s limit it can handle? Plugins like Fab Filter Pro Q allow much higher Q settings.
Also, would it be reasonable to counteract the dips I’m seeing in the plots?
Does anyone see something that needs to be corrected in addition to the 37.5 Hz peak?
Can you elaborate what exactly is strange in the plots?
Here are two pictures of the room/speakers. Speakers are ATC SCM 19 and they are approx. 150 cm from the side walls and about 50 cm from the rear wall.
Looking at those measurements, I would say the biggest problem is a lack of bass and warmth in your system. In fact, the peak at 37Hz looks to be about at the right level if you put the level at around 78 dB (which is reasonable since thats the level of the 300 - 1kHz).
But with a 78 dB target, the dips in lower frequency will be to large for REW to try and correct, so put the target at 70 dB and do a full range correction on the average, how does that correction look?
You could also try to add some filters manually, something like one Q3 at 150Hz with +10dB and one Q5 at 60Hz with +15dB (it wont make the graph looks pretty but it should improve the sound).
So I averaged all measurements and set the target to 70 dB. I basically get filter settings that dampen a number of target frequencies (see attachment) but wouldn’t boost anything. My question is: which filter settings are required in the ‘Filter Tasks’ pane for ‘Individual Max Boost’, ,Overall Max Boost’, and ‘Flatness Target’ to lift regions in the bass and above.
Individual boost is how much a single filter can boost, max boost is how much all filters together are allowed to boost. Flatness target is how flat REW will try to make the curve, and I often use 3 to allow some irregularities and make sure REW don’t overcompensate (the curve wont look as good but will probably sound better).
But here is where a little trial and error comes into play. There is no absolutes about the sound you like, only opinions. So try to boost everything to the target, and try to limit the boost or even fully prevent it, and see what you like best.
It also depends on how low the speakers plays, you should not try to boost for example 50Hz if the speakers only play at 100% to 70Hz (that will only boost distortion).
Here is a measurement I found of your speaker, done in an acoustically dead room:
No, I am not using SAM. The thing is that I have a first generation ATC SCM 19 and Devialet has only SAM filters for the second generation. I can try, nevertheless, with the SAM for ATC SCM 19 and see what happens.
So I had the target set to 70 dB, and flatness target to 3 dB, while individual/overall boost were set to 0 dB just to avoid any boost below 80 Hz. Here’s the response curve and the filter settings. Does that look somewhat all right? Nevertheless, the restriction of max Q in Roon remains, correct? What happens if I’d export the filter settings to a wav file and let Roon use this. Would the corrections still be lemited within Roon’s constraints?
You could allow some boost in the 100 to 200 region, so maybe set match range from 90 and allow boost. I would also make a little more HF slope although that’s more of a personal preference.
Still can’t understand that huge dip between 50 and 100 Hz. In my opinion there’s something wrong with the measurements or otherwise placement of the speakers… also that big seat does no good…
I should redo measurements and play a little with the speaker placement.
Its the speakers, ATC are excellent speakers but somewhat limited in bass. Look at the frequency response picture I posted above for the ATC SCM 19 speakers. Then you get a big peak in bass due to room nodes, which can be (as seen in his measurement) well below what the speakers typically can manage.
Btw, be very careful about bass traps in your room, chances are they will decrease the bass in the 50 - 150Hz even more but leave the peak at 37Hz virtually untouched.
Unless you have a subwoofer hidden in there, which would totally change everything!
Yeah, you’re right about that, they are no bass monsters. They start to roll off at 80 Hz and the -6dB point is somewhere at 50 Hz. So in room they should go to 40-50 Hz without a problem. I think something is sucking out the bass out of this room…
Maybe Paul_Jeno could give is his room dimensions?
