More recent. Still work to do. Wife's foot-rest thing pushed out of the acoustic path to the ears. TV all the way back, now a Mac mini to run Audirvana rather than my laptop. Similar absorber against window on the right for the first reflection. Son covered up Sinatra with a map of the European football clubs...
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80Hz and below you can't localize the sound even if you are in a large space.
So no matter what you're *never* going to localize 80Hz and below. You can be 100% certain that stereo subs are useless. (assuming subs are 80Hz and below.) I've seen people locate their subs like mains and think they can hear stereo down to 20Hz. They cannot. They are imagining things.
That means your next concern becomes 80Hz to 300Hz based on your specific room size. That's the region that has confused me in the past. Which is why I linked John k...'s post that cited the research paper by Juha Backman.
IMO, follow that paper's advice. However, if you need to make compromises remember the Earl Geddes quote from the original post, that is the region to make the compromises because even though we can localize in those frequency ranges we aren't very good at it. Things get more critical above 1,000Hz.
Consequently, I don't think you are at high risk of messing anything up in your region of concern and I don't think you have any great rewards waiting if you get it perfect.
To a certain extent, if Geddes is right, the sparsely modal region isn't very interesting. That's why I'm wondering about the 1,000Hz and up region. Are there regions of various importance within that region so we can decide where to make compromises too?
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Big enough....
Same here for music styles + some rock & Pop as well + some traditonal music from all the world 🙂 But rock and Pop spl level below 40 hz is often weak in most of that musics annd regarding... if you look at most of the big classic events in venues... not too much energy above 1 k and below 40 hz from what I noticed. Certainly very experienced sound ingeeners here have an opinion. Rock concerts are something else: amplified, etc !
So I surmise (?) discussion is not the same regarding the music genres maybe ?
That's the cool JBL monitors with controlled directivity ?
All my speakers for the bass are not big (small Sd) but sealed ! : slower slope than ported, I find it mre musical and good for all genres. Is it because the cut off is less stiff for the room and a the same time moves more modes ??? I mean -10 db for example is often higher with sealed bass cabinet because the slower slope.
All that subs for me are shaking everything (you talked of wood as well?!) and acts half as counter back wave cancelation... Me prefers not to gives too much to the room in the lows 🙂 (but the punch in the 80/200 hz that needs also good tweeter set up... perhaps what Dr Gedlles are saying about the 1 K hz and more ????
Same here for music styles + some rock & Pop as well + some traditonal music from all the world 🙂 But rock and Pop spl level below 40 hz is often weak in most of that musics annd regarding... if you look at most of the big classic events in venues... not too much energy above 1 k and below 40 hz from what I noticed. Certainly very experienced sound ingeeners here have an opinion. Rock concerts are something else: amplified, etc !
So I surmise (?) discussion is not the same regarding the music genres maybe ?
That's the cool JBL monitors with controlled directivity ?
All my speakers for the bass are not big (small Sd) but sealed ! : slower slope than ported, I find it mre musical and good for all genres. Is it because the cut off is less stiff for the room and a the same time moves more modes ??? I mean -10 db for example is often higher with sealed bass cabinet because the slower slope.
All that subs for me are shaking everything (you talked of wood as well?!) and acts half as counter back wave cancelation... Me prefers not to gives too much to the room in the lows 🙂 (but the punch in the 80/200 hz that needs also good tweeter set up... perhaps what Dr Gedlles are saying about the 1 K hz and more ????
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I would be careful of writing anything is such absolute terms, much of what you say will be true in most cases but David Griesinger has examined this as part of his search for getting more 'envelopment' in small rooms and he puts forward an argument for separate left and right subwoofer frequencies.
He is almost the only well known and respected person suggesting that but if he thinks there's something in it then I would not dismiss it out of hand.
Something in terms of localization or something in terms of something else?
In the context of localization, you can't localize an 80Hz source, especially in a small room because by the time your brain recognizes what it has heard your ear has been hit from all different directions.
If says there is another reason then it might be worth doing whatever it is he suggests. But we need to know what he says and why he says it.
In the context of localization, you can't localize an 80Hz source, especially in a small room because by the time your brain recognizes what it has heard your ear has been hit from all different directions.
If says there is another reason then it might be worth doing whatever it is he suggests. But we need to know what he says and why he says it.
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My point is to be careful of confusing what is generally true with what is absolutely true.
Many of these perception thresholds vary by time, distance and intensity.
This is a reasonable article on Griesinger's experiments
Spaciousness of Bass: Is Stereo Bass a Myth or Reality? | Audioholics
I don't think so, most of his papers are on his website if you want to read them.
Yes, the monitors (mid-field) are a fairly old design, but I think some of the first to manifest Harman's move toward controlled-directivity.
One of the nicest benefits to me of deep, effortless bass is actually an improvement in the sense of venue in concert halls/recording spaces (and the punch in pop stuff is fun, too). And yes, much of what a casual listener would describe as bass is actually mid-bass, 70-150 Hz or so.
I had sold off all of my equipment before moving to BZ for 3 years. I had been through years of all the exotica before that. My goal as I re-built was timbral accuracy and a sense of unconstrained dynamics.
I agree re. sealed bass. Anything I build will be sealed. I tried stuffing the ports without much success, but like that the subs are sealed.
And yes, the multisub approach is all about smoothing out the bass, decreasing the typical peaks and nulls around the room. In the States we have to deal with sympathetic vibrations from our sheetrock walls (Geddes uses two layers separate by compliance to absorb bass).
My next move is to tear out the ceiling sheetrock and install thick absorption extending into the attic, both to reduce higher-frequency reflections (the "ceiling cloud" described in monitoring circles), and to mitigate the ceiling-to-floor modes. Have to work on the wife 🙂
A parametric EQ in the RME at 70 Hz has also been very helpful.
Bill
yup... te major frequency ra👎ge is the woman voice, good luck indeed without the SAP ! (spouse acceptance passeport)...
Well concrete walls and light plaster from Paris walls have also their problems...
Well concrete walls and light plaster from Paris walls have also their problems...
Yes, he said you want to excite as many modes as possible. If your low frequency sources are correlated they activate the same modes.
Griesinger made a YouTube video on this topic, Low Frequency Envelopment in Listening Rooms. Here's his video description:
He's describing his multi-sub strategy. "Stereo" in this sense means two sources, located laterally to the sides separate from the mains. In the video he describes how he tried to position his full range mains (in his home) to produce the desired effect but it didn't work.
How does this help billshurv? It gives him flexibility with regard to the idea one should design their mains to play down to 80Hz. Actually, it's more than that. It means he has nothing to gain from building mains that work all the way down to 80Hz, there's no benefit. He's better off building separate low frequency sources -- detached from his mains -- so he can position them properly in the room. See Post#11 Major Frequency Ranges
I think the article you linked is helpful and includes the following quote:
Stereo subs aren't going to supply imaging. And if you want to achieve bassiousness, your mains aren't going to do it either. You'll need low frequency sources separate from your mains.
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For me the most critical region is around 2KHz to 5KHz. If there is a poor directivity mismatch between midrange and tweeter, midrange induced breakup distortion, tweeter strain or anything that causes a peak (diffraction etc) then this leads to a fatiguing speaker.
Hi,
The 80hz rule of thumb come from different sources ( mainly THX certification where satelites are cut at this freq) but it is not because of imaging in the low, more about to have whole fundemental range of 'typical' instrument emanating from one point ( or the closest possible to a point source).
I agree about modal behavior of room determining the freq 'imaging' or localisation (iow the smaller the room the higher the modal freq and the higher in freq where you can localise) but have you ever played with a 2.1 system where you can adjust the .1 cut off freq? Because if you have tried some 150hz and up as cut off you may have experienced unatural feelings about source which are not located in the same physical position (the sub is usually in between satelites or wherever it is confortable to locate it). It is one of the reason about the 80hz limit to keep 'coherency' of emmissing points.
BradleyPn, you seems quite sure about 80hz being a threshold for localisation but have you ever had the possibility to test that outdoor on a big soundsystem ( without room modes to skr.w things up)?
If no you should try and hear by yourself if this is a truth or a 'rule of thumb' (about localization) in room, you may be surprised (or not as there is variation between individuals).
And about Earl Geddes's quote i interpret it differently than you: it is a case of coupling to room acoustic not an absolute range of frequency of importance.
In this case ( acoustic and loudspeaker combo) Earl quote make total sense ( RFZ are usually effective from 1khz and up sometimes an octave lower but this is rare) but if you forget the acoustic ( which seems to me from your statement) and define some frequency range as being more important to others then the inteligibility range make much more sense ( 300hz to 4,5/6khz depend where you find your info) because this is where understanding of speech reside ( telephone bandwidth).
The 80hz rule of thumb come from different sources ( mainly THX certification where satelites are cut at this freq) but it is not because of imaging in the low, more about to have whole fundemental range of 'typical' instrument emanating from one point ( or the closest possible to a point source).
I agree about modal behavior of room determining the freq 'imaging' or localisation (iow the smaller the room the higher the modal freq and the higher in freq where you can localise) but have you ever played with a 2.1 system where you can adjust the .1 cut off freq? Because if you have tried some 150hz and up as cut off you may have experienced unatural feelings about source which are not located in the same physical position (the sub is usually in between satelites or wherever it is confortable to locate it). It is one of the reason about the 80hz limit to keep 'coherency' of emmissing points.
BradleyPn, you seems quite sure about 80hz being a threshold for localisation but have you ever had the possibility to test that outdoor on a big soundsystem ( without room modes to skr.w things up)?
If no you should try and hear by yourself if this is a truth or a 'rule of thumb' (about localization) in room, you may be surprised (or not as there is variation between individuals).
And about Earl Geddes's quote i interpret it differently than you: it is a case of coupling to room acoustic not an absolute range of frequency of importance.
In this case ( acoustic and loudspeaker combo) Earl quote make total sense ( RFZ are usually effective from 1khz and up sometimes an octave lower but this is rare) but if you forget the acoustic ( which seems to me from your statement) and define some frequency range as being more important to others then the inteligibility range make much more sense ( 300hz to 4,5/6khz depend where you find your info) because this is where understanding of speech reside ( telephone bandwidth).
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I came across this paper on sound source localization.
Sound source localization depends on 3 types of cue: 2 binaural (ITD and ILD) and 1 monaural (HRTF).
Sound source localization depends on 3 types of cue: 2 binaural (ITD and ILD) and 1 monaural (HRTF).
