You can see in that graph that the problem is composed of quite a few separate narrow dips combining to form a bigger problem.The dip got way narrower, shallower and moved upwards - really cool!
You can see in that graph that the problem is composed of quite a few separate narrow dips combining to form a bigger problem.The dip got way narrower, shallower and moved upwards - really cool!
Understood but it could be as simple as moving one speaker relative to the other. I'm only advising to be sure what is happening before deciding which band aid to applyFully agreed, however physical solutions are not an option in my friend's living room hence the band aids
A very important point, manipulating phase while only looking at graphs is an all too easy way to destroy the sound.
For summation problems like that it is important to look at the cause, why do the two speakers cancel each other out? Looking at the SPL and Phase is one way, the spectrogram can also give a clue as often nulls develop in time. Sometimes it is better to attenuate the problem frequency range in one speaker and boost the other side a little to compensate so they don't fight each other as much. Placement can often solve these sort of things without any processing being needed.
Processing like Dirac needs to be the icing on the cake not a band aid for taming acoustic issues that are easily solvable with physical solutions.
You mean the "decay time", which is caused by room's acoustics. Normally the only practical solution is using bass traps, which are absorbers that work on the bass range of the audio spectrum.By ringing I mean the sound of decaying bass notes in the room (post ringing, for example after a kick-drum is hit)
As I explained above, my odd shaped living room produces really weird ringing phenomena that was resolved by the M/S EQ-ing method after years of trying many things
There are two problems presented, the one belonging to the thread title and a second related to a different system with an issue between the two channels integrating.I don’t see how physical solutions can solve this. Unless you’re telling people to live in anechoic chambers. Because at the end of the day in a stereo both speakers should be the same distance away from the listener.
I agree with the fact that everything should be tested by ear, and my corrections are usually not as brute force as OP’s but I don’t see how a physical solution can solve this problem (aside from getting an AVR and a center channel)
A very important point, manipulating phase while only looking at graphs is an all too easy way to destroy the sound.
For summation problems like that it is important to look at the cause, why do the two speakers cancel each other out? Looking at the SPL and Phase is one way, the spectrogram can also give a clue as often nulls develop in time. Sometimes it is better to attenuate the problem frequency range in one speaker and boost the other side a little to compensate so they don't fight each other as much. Placement can often solve these sort of things without any processing being needed.
Processing like Dirac needs to be the icing on the cake not a band aid for taming acoustic issues that are easily solvable with physical solutions.
I set the AP filter at 55Hz Q=3.5
My friend did not have the time to test (listen to) the AP filter I sent him
However I did test it on my own system
This is how my Left and Right channels look like with the L+R summation highlighted
View attachment 278570
Pretty nasty cancellations between 50-60Hz and at about 150-180Hz
I tried to fix the 50-60Hz dip with an AP filter (54.5Hz Q=7) in Jriver's PEQ applied on the right channel
View attachment 278571
As you can see the simulation (and also the actual measurement) looks much better
But when I listened to it I could hear that some bass notes were actually 'crawling' out of the stage from the right channel - as if those notes were coming from a third loudspeaker outside the stage
This is how the spectrogram looks like for the normal summation:
View attachment 278573
and with the AP filter
View attachment 278575
I am wondering if it is the elevated peak of the energy curve that I can hear.... any comments are welcome
For me the conclusion is that these tricks with the AP filters do look great on the FR curve but when actually listened to - not really
I guess @ernestcarl that was your conclusion too
Use filtered IR's. REW's Overlay screen has a few predefined settings, but since I discovered the Alignment Tool > Impulse alignment, it has become much easier.I would love to understand if there is a better way than just trial and error