Hello, welcome! I'm back in that unhealthy vortex of dissatisfaction that is created when you try to listen to music and you are convinced that there is a way to listen to it better. I've had a pair of old but good MTM transmission line tower speakers for a while now, so far listened to in my living room in a 'calm' state, all ok, but perhaps 'too ok' in the sense that I a little bored, and I said to myself: why don't I do some measurements to see if I can liven something up? I then saw that in my opinion the Morel was cut too high, thus losing much of its expressiveness, and causing, again in my opinion, a bad off-axis response, because the mid-high range was entrusted to the midwoofers (Vifa 6.5'' ) up to too high; also the time alignment was good but could be improved. This is what I achieved with fairly simple changes (also perhaps understanding how to avoid the mistakes I made before which always led to sibilance problems):
ORIGINAL situation
MODIFIED situation
OVERLAY of the two (I attach the simulations only for the convenience of superposition and because they are quite faithful to the measurements, which only have a more regular and flat trend)
A more open and emotionally engaging, dynamic, 'fresh' and pleasant mid-high range, which in my opinion exploits the expressive potential of the beautiful Morel much more.
Furthermore, I also installed 5 cm sound-absorbing panels on the rear wall behind the speakers, which are approximately 35 cm from it, for a height and width equal to the height of the speakers; the mouth of the transmission line is on that side about 35 cm from the ground.
The problem is that now I can hear the basses well everywhere in the room... except the listening spot on the sofa in the middle of the living room!! When I sit there, the bass disappear into thin air, if I walk around they reappear in all their beauty.
My question is: what could this phenomenon depend on?
Thank you to all!
ORIGINAL situation
MODIFIED situation
OVERLAY of the two (I attach the simulations only for the convenience of superposition and because they are quite faithful to the measurements, which only have a more regular and flat trend)
A more open and emotionally engaging, dynamic, 'fresh' and pleasant mid-high range, which in my opinion exploits the expressive potential of the beautiful Morel much more.
Furthermore, I also installed 5 cm sound-absorbing panels on the rear wall behind the speakers, which are approximately 35 cm from it, for a height and width equal to the height of the speakers; the mouth of the transmission line is on that side about 35 cm from the ground.
The problem is that now I can hear the basses well everywhere in the room... except the listening spot on the sofa in the middle of the living room!! When I sit there, the bass disappear into thin air, if I walk around they reappear in all their beauty.
My question is: what could this phenomenon depend on?
- from the fact that the off-axis response has worsened rather than improved as I expected (and therefore I haven't understood anything about it so far), and then I 'feel' the mid-high range stronger only on-axis?
- from the fact that before I was more careful to 'look' for beauty in the medium-high range and didn't care about the low range? Yet I am convinced that there wasn't that much difference in bass between sitting and standing....!
- from the installation of sound-absorbing panels?
Thank you to all!
Hi, sound wavelength on low frequencies is similar in size of your room so the room has strong effect on those. However your speakers are relatively small in size and have about no effect (directivity) on lows, unless it was a dipole or cardioid speaker where there is multiple sound sources that together make strong directivity.
Speaker position matters a lot, and also listening position matters as you have discovered.
Read on about room modes, about room correction, about speaker placement, to get some hints.
In practice, you must adjust your positioning to get somewhat balanced bass. You could also use a separate bass system that is also size of your room, and DSP to tune that system to reduce effects of room modes. Effective bass system is at least two subwoofers, people often target for four and distribute them different sides of room. Find information about multisub systems, also double bass array and virtual bass array.
Speaker position matters a lot, and also listening position matters as you have discovered.
Read on about room modes, about room correction, about speaker placement, to get some hints.
In practice, you must adjust your positioning to get somewhat balanced bass. You could also use a separate bass system that is also size of your room, and DSP to tune that system to reduce effects of room modes. Effective bass system is at least two subwoofers, people often target for four and distribute them different sides of room. Find information about multisub systems, also double bass array and virtual bass array.
It's difficult to admit it, the difference between before and after the modification was macroscopic and the environment was always the same, the fault was not of the misunderstood off-axis response or of something scientific in any case, but..... of having wired my self-built measurement box bad, as it had the output connected in anti-phase and since I started the modifications it has always remained connected for convenience....! I apologize, obviously I'm getting older....!
It may be better to archive this thread..... Thank you however.
It may be better to archive this thread..... Thank you however.
