I don't know, those just seem like random lines beaten into submission by a monkey that has no clue.
Target spectrogram value should be somewhere around 200-400ms.
All of your values are around 200ms except from 100Hz to 200Hz
I don't know, those just seem like random lines beaten into submission by a monkey that has no clue.
No. You can measure without sub for check. Strongly delayed energy due to some kind of reflections, IME it's unusual for the near field.Is this caused by +2 Lf trim?
No. You can measure without sub for check. Strongly delayed energy due to some kind of reflections, IME it's unusual for the near field.
Yes, this is a reflection off the mattress, surely. Most use slick, mercerized cotton for the cover fabric, which is probably more reflective than drywall at HF.Could be that the mattress is actually reflecting the 10khz range back sooner than the ceiling was and causing some bump in response there? Very odd, not expected, but if the fabric is dense enough covering the mattress, really HF might not make it through?
I've tried drawing some monoliths into my room plan, but 10 cm thick blocks are just too much of an eyesore is such small space.
I think the only viable solution is to rip the ceiling down and stuff a bunch of rockwool under the dryboard - but it's a tad too much for now, I've just finished painting
But there is hope - I have 30 cm deep bookshelf planned just above the monitors. Position looks perfect, covering the connection point of ceiling and a wall, almost like a proper bass trap. Drivers will be almost flush with it's edge, maybe slightly recessed like 1 cm. At a first glance it should actually cover huge part of a mirror reflection from a ceiling at my listening position.
How good are books as absorbers in 100-200 Hz range?
View attachment 256358
Agreed. Bookshelves on the back wall seem to be popular, but whatever is wrong at the MLP, the shelves there will only make worse...Yeah . . . that's probably not a good idea.
If you can stomach it, I would look at putting some foam on the slanted ceiling above the desk, behind the monitors, and on the walls directly to the left and right of the desk. If your problem is high frequency comb filtering, this is where most of your problems are coming from.
Ah, got it, sorry.I only care about 150-250 Hz range as shown on spectrograms in earlier posts.
Basically, yes. The lower the frequency you want to treat, the thicker the material needs to be. Putting ~30cm inside some of the kallax cubes could actually be helpful.I guess where I can stuff the biggest mass of absorbing stuff, but that's just a wild assumption.
This is mostly to add more material overall, the long dimension of the trap won't tend to change the performance that much.Also, what about height? As seen in couple of videos, usual triangular bass trap for a corner spans from the floor to the ceiling.
For the same length and quantity of material, it *should* work about the same. The real issue is that you need the material to be physically located at a place where the velocity of the air due to sound waves is relatively high. This tends NOT to be the walls, so the corner bass trap thing is more because it's not practical to put them in other places, not because they work best there. Also, depending on the room itself, the nodes might be closer to one corner than the other at a given frequency. You can find this out by moving your mic around the room while playing tones.Would it work when placed only in the upper corner, like over the wardrobe?
Also, depending on the room itself, the nodes might be closer to one corner than the other at a given frequency. You can find this out by moving your mic around the room while playing tones.
Yeah . . . that's probably not a good idea.
I *think* that's how it works but I am somewhat overstating my knowledge here as I haven't done it that way myself. In theory, all of the nodes need to be 1/4WL away from the wall, or more - (which is partly why the treatment needs to be so thick) but in practice walls are not perfect reflectors, and you have more imperfect reflectors beyond the wall, so it can vary.That's really interesting tip.
Like, would it work if I just played pink noise spanning 150-250 Hz range and check potential treatment places with a mic for the loudest signal?
Experiment with two mattresses, one each from behind the speaker to cover about 40-50 cm against center of the middle and a bit up on the wall. Then get or build "real" damping panels behind. 10 cm deep frame with rock-wool covered with perforated board, and covered with 6 cm well-formed acoustic foam.I'm sorry, left the amplitude in log scale. The difference with the mattress is more visible in linear.
No mattress:
View attachment 256267
Mattress on front wall:
View attachment 256269
Mattress on the ceiling:
View attachment 256270
Looks like it fixes something around 200 Hz. I guess couple of those monoliths might do audible difference. It breaks something in the 10k area tho.