Don't forget your brain will adapt to the acoustical characteristics of the room.
Yea, I would say that's likely. It would act just like a free field - outdoors. I have not heard one, but the concept is solid and probably will do what they say - no modes. The question is: Is that what you want to do? Modes are not bad things if they are not high Q. Broaden them with more overlap and the Schroeder frequency falls. The modes then still carry some energy and add to a longer held signal for a better bass perception. Smooth it all out and I'd say that's the best that you can do. In my room there is only a single mode that is evident at about 30 Hz. - the room length mode. It may even be pumping the doors which is why it's a higher Q.
I still like listening outside / no room. But, I built a system for outside. It wouldn’t fit in any anechoic chamber I know of but I would like to try it.
Barry.
Barry.
Which plot do you need? FR of my stereo speakers? Or the one with three subs? I can mail you REW files where you can see more details.
I have some damping but sadly it's not very effective. Side walls are coveres with 20 cm of glasswool and front wall has some rockwool absorbers (8" thick). Walls are solid (brick, concrete, insulation). None of this (and neither different speaker/seating locations) didn't improve my stereo response. This is why I'd like to try "the Geddes method". I have 4 subs now. A picture would not show much because I put a lot of effort to hide all this stuff.
That is correct. And you can get a decent sound with not that great FR. I'll be ready to send my FR to whomever who wants when it'll put a smile on my face.
Hm, to be honest, I never really though this could be an issue. My seats are old cinema seats with metal construction placed on a carpet floor. Thanks for the tip. It sure is worth checking out.
What do you mean by awful resonances? Were they visible on a graph (and then gone when sofa was rebuild) or did you feel them while sitting and listening?
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au contraire
Bass outdoors is as good as it gets imo..... the gold standard.....
…..when there is sufficient clean SPL; and no buildings, walls, etc, to build up reverb
Dont forget to consider mso
Tend to agree on bass outdoors as being the gold standard. Just need enough of them big subs
Thank you, nice setup you got there.Dont forget to consider mso
Tend to agree on bass outdoors as being the gold standard. Just need enough of them big subs
I've heard about MSO before. Just help me clarify some basics: you measure each sub individually and then import the measurements into the MSO? The program then provide optimal settings for each sub? What settings are we talking about?
What if one doesn't have any external DSP? Some subs have all kinds of settings (hi/lo pas filter; hi/lo slope, 8 band PEQ ...). I wonder if this could replace an external DSP processor?
Thank you, the pics in that thread are outdated though. Here are more recent ones.
Indeed you measure each sub (and main) at least the same amount of positions as dsp channels. Than you import those measurements, MSO calculates the resulting combined response at each position. You than add dsp filters and start optimizing. Finally you export those dsp filter settings (and at least check the result once).
You do need an external dsp though since manually setting low pass filters and gains using knobs is not accurate enough.
Indeed you measure each sub (and main) at least the same amount of positions as dsp channels. Than you import those measurements, MSO calculates the resulting combined response at each position. You than add dsp filters and start optimizing. Finally you export those dsp filter settings (and at least check the result once).
You do need an external dsp though since manually setting low pass filters and gains using knobs is not accurate enough.
Thx
MSO is just a program than can "try out" dsp settings. So every parameter that is available in a dsp: delay, gain, xover slopes (all kinds), all pass filters, parametric EQ filters, shelving filters, polarity reversal, notches. So all filters that exist in IIR dsp's. You're free to add filters as you see fit.
That Velodyne also had music/HT setting and contour filter. You can't simulate those of course as those are unknown EQ filters. Xover slope could be LR24 but maybe also some other slope. But you're welcome to try it out.
MSO is just a program than can "try out" dsp settings. So every parameter that is available in a dsp: delay, gain, xover slopes (all kinds), all pass filters, parametric EQ filters, shelving filters, polarity reversal, notches. So all filters that exist in IIR dsp's. You're free to add filters as you see fit.
That Velodyne also had music/HT setting and contour filter. You can't simulate those of course as those are unknown EQ filters. Xover slope could be LR24 but maybe also some other slope. But you're welcome to try it out
.
OK, so MSO is proposing filters which you can insert in a DSP? Am I getting this correctly?
I don't see any DSP unit at your pics...
Contour is for boosting or cutting the signal in reponse to specific types of source material. It's like changing the volume at only one bass frequency. It can be turned off.
Music/theater setting is not really a part of signal processing. It's for controlling servo gain.
I don't see any DSP unit at your pics...
Contour is for boosting or cutting the signal in reponse to specific types of source material. It's like changing the volume at only one bass frequency. It can be turned off.
Music/theater setting is not really a part of signal processing. It's for controlling servo gain.
Beige,
I'll send you a pm with my email and I can take a look at your REW files. Specifically I am looking for measurements between 20-300Hz of:
1. Main loudspeakers only
2. Main loudspeakers + the subs
And a measurement of the mains only > 300Hz to see how the levels of the mains integrate with overall levels of all subs together.
I never used MSO so I can offer no opinion on that. I do know that besides Geddes, Toole and others, the Minidsp website has a nice summary on multi sub optimization:
Tuning multiple subs
Best,
Anand.
There were a lot of resonances in the LF band and sitting on the sofa you felt them all - a very resonant response. These will not appear in a FR plot because they don't radiate sound into the room. But when you sit on a resonant structure the vibrations shake your body and excite the ear mechanically. You sense this as if you were actually hearing the resonance, but it is not in the air (so to speak), but in the mechanical coupling to your body. I have seen this happen many times before, most notably in cars. Studies have shown that much of the noise that you perceive in a car is actually structure borne, not airborne.
au contraire
Bass outdoors is as good as it gets imo..... the gold standard.....
…..when there is sufficient clean SPL; and no buildings, walls, etc, to build up reverb
I don't see it that way. Outside you have to push up the bass level quite a bit to get it to sound full. That's because of the lack of reverberation, which the room adds. But small rooms have modal issues which you have to deal with.
Interesting. What can be done here? Replace the whole thing or what did you do when rebuilding the sofa? I assume covering the metal parts with some sort of foam would help much?
Sometimes braces work well, sometimes reinforcing the joints with a damped glue like Liquid Nails for Subfloors. It's hard to describe all the common means of noise control because it is a huge subject, but there is always something that can be done.
I don't remember the specifics of the sofa, but I do remember that before and after was quite significant.
I won the Henry Ford Technological Achievement Award many years ago for my work in understanding how people perceive noise in cars. A large amount of that work was on the huge impact that structure borne noise has. When you drive a car with engine imbalance (as virtually all engines are not naturally balanced, some much worse than others) you perceive this and almost without exception people sense that they are hearing this. But that is not the case - you feel it (and hear it) but you think that you are only hearing it - humans really can't tell the difference because they both excite the cochlear hair cells, just in different ways. If there is a structure that is vibrating just place your hand on it and it will sound louder - but it's not actually - you just gave it another path into your senses.
I don't remember the specifics of the sofa, but I do remember that before and after was quite significant.
I won the Henry Ford Technological Achievement Award many years ago for my work in understanding how people perceive noise in cars. A large amount of that work was on the huge impact that structure borne noise has. When you drive a car with engine imbalance (as virtually all engines are not naturally balanced, some much worse than others) you perceive this and almost without exception people sense that they are hearing this. But that is not the case - you feel it (and hear it) but you think that you are only hearing it - humans really can't tell the difference because they both excite the cochlear hair cells, just in different ways. If there is a structure that is vibrating just place your hand on it and it will sound louder - but it's not actually - you just gave it another path into your senses.