Room Correction... I like it!

[steadyshot]

It depends from the single case and if you use a subwoofer or not but I believe it can be.
I used to measure with house curves with calibrated mic and then adjusting with the WiiM's PEQ. The result was very good, until I got (for some reasons) a Dirac equipped amplifier. Whilst level correction it's important, nothing is essential as the time alignment of sub and speakers. It was an essential step up. If I understood well, WiiM's RC it's a sort of automated house curve but it can do nothing in impulse alignment and phase. Eve if you can move in the room as required (frequently not allowed to) the subwoofer and the speaker, you won't be able to get such precision.
So, good there is RC, better if it will align time in the future...

Very true …some frequencies are in the same phase others are not . You need individual time alignment which is complicated and adjusting only the amplitude does not work in that case

 

[slartibartfast]

This can be tested with REW acoustic reference feature? (I know using HDMI can, but on a regular hifi?)

Not sure what REW acoustic reference is but you can check the effect of the delay using the RTA or normal sweep measurement.

 

[harkpabst]

That's good but it's not as accurate and it's available on WiiM amp only.

Yes, because sub out is available with the WiiM AMP only (and WiiM Ultra and WiiM AMP). As long as the streaming DAC doesn't have a separate subwoofer output, there's nothing that could use further time alignment.

Regarding accuracy, isn't 1 ms step width sufficient? It's good for 34 cm steps at frequencies where the typical wavelength is usually >= 400 cm. How much changes the relative distance to mains and subs if you just move your head 20 cm to the left or the right?

Personally I am not convinced that time alignment outside the crossover region is all that important for correcting room effects.

 

[merifon]

Yes, because sub out is available with the WiiM AMP only (and WiiM Ultra and WiiM AMP). As long as the streaming DAC doesn't have a separate subwoofer output, there's nothing that could use further time alignment.

Regarding accuracy, isn't 1 ms step width sufficient? It's good for 34 cm steps at frequencies where the typical wavelength is usually >= 400 cm. How much changes the relative distance to mains and subs if you just move your head 20 cm to the left or the right?

Personally I am not convinced that time alignment outside the crossover region is all that important for correcting room effects.

Accuracy is enough but requires a lot of manual work that Dirac system does automatically and very well. Don't remember if phase it's finely adjustable also. There are also huge differences from left to right channel, above all if one sub is used. Dirac manages all speakers timing and not subwoofer only
Yes, time alignment and phase are crucial for subwoofer crossover region. I don't remember what Dirac does for higher frequency also. Personally I prefer coax speakers like my kef ls50 meta, due to the lower parallax in the position of the drivers, they are less prone to receiving interference from early reflections. It's a sort of my bias but is supported by measures.
Regarding measures done at 20cm distance, I got narrow hole in 70Hz zone on right ear only position and no hole on left ear position. Cross reflection from the walls can make difference even from one side of the head to the other,despite wavelengths.

 

[harkpabst]

Accuracy is enough but requires a lot of manual work that Dirac system does automatically and very well. Don't remember if phase it's finely adjustable also. There are also huge differences from left to right channel, above all if one sub is used. Dirac manages all speakers timing and not subwoofer only

It's a matter of philosophy or - keeping it to a more practical level - a matter of approach if automated room correction software should even try to determine the distance to each and every speaker. Most of the typical AVR systems regularly fail doing so.

I love the way my Lyngdorf Amp allows to enter distance values for each speaker and each subwoofer (up to two of them) manually and in addition allows to add an amplifier/DSP delay for the sub. But in the end it's very unusual to have hugely different distances to the main speakers in a 2 channel stereo setup. A single sub might not be placed in the ideal space right in the middle between the main speakers, but in this case the maximum crossover frequency is pretty limited, as the delay of the sub with respect to the mains cannot be perfectly corrected for both speakers, anyway.

Personally I prefer coax speakers like my kef ls50 meta, due to the lower parallax in the position of the drivers, they are less prone to receiving interference from early reflections. It's a sort of my bias but is supported by measures.

No need to convince me here. Finally, it's all down to a very symmetrical off-axis response. A coaxial design is potentially superior here, even more so, if the baffle is very symmetrical and offers highly rounded edges. LS50 (Meta) may be highly regarded, but they are still underestimated by most.

 

[merifon]

A single sub might not be placed in the ideal space right in the middle between the main speakers, but in this case the maximum crossover frequency is pretty limited, as the delay of the sub with respect to the mains cannot be perfectly corrected for both speakers, anyway.

Especially around crossover wavelengths, it's the distance from listening point to each speaker that matters from time point of view, regardless they are on left or right side. A single pulse at 70Hz has to reach your ears at the same instant/phase and this can be easily corrected since sound is a pressure wave moving towards listener. If the subwoofer is on the same position of one of the main speakers and the other is symmetrically placed I don't see particular difficulties.
I would be curious to hear RoomPerfect results and Dirac on same environment.