There is no ratio to hypothesize: it is dependant from room dimension/material ( 'RT60' at 2khz) and the directivity of system ( Vertical/horizontal or Q as Earl use it - directivity related).
Big or small system doesn't matter. It may be of importance ( size of system) wrt point source behavior and 'integration' of multiple drivers though ( for big systems): it may require too much step back to be at critical distance if room is too small, directivity too wide or a mix of both...
Big or small system doesn't matter. It may be of importance ( size of system) wrt point source behavior and 'integration' of multiple drivers though ( for big systems): it may require too much step back to be at critical distance if room is too small, directivity too wide or a mix of both...
Last edited:
In all control rooms i've been listening spot was always located at critical distance. It is a prerequisite.... not something desirable. 
Of course as 'RT' is a variable into the equation the more damped the room the bigger the critical distance will be ( for a given room size and loudspeaker directivity).
Of course as 'RT' is a variable into the equation the more damped the room the bigger the critical distance will be ( for a given room size and loudspeaker directivity).
Last edited:
^ may i ask why? Headphones are better to make a room disapear!
Use the calculator linked Camplo. It'll give you an idea of what to expect ( and the amount of rockwool you'll need to drop RT to the critical distance you planed - listening position).
Im all about it and I appreciate the schooling! Headphones are as you say but provide non of the tactile feedback. Regardless of that fact people are still successfully mastering on headphones but In my experience bass, without tactile feedback is lost on us.... The same store miss judgment of levels happens with the top end of treble, as well. Also this system was meant to create the best mastering experience in a bad room, and I haven't figured out if I succesfully add active cardioid to the system, but regardless of this, creating the most possible direct energy was the other aspect to focus on.
Thank you, finally some reading material on measurements =)
Last edited:
Hello Camplo
Are you or have you considering assisted alignments? As long as you have the power handling and excursion they can work quite well and extend your response significantly. Example would be JBL B380 with a Q2 +6dB @ 26Hz at box tuning frequency.
I use that same alignment with 2216nds and it changes the F3 from 47Hz to 25Hz.
Rob
Rob, do you use the 2216ND in separate sub enclosures or in a 2 way configuration?
It's a stunning piece of engineering, no doubt, but it seems to be a kind of double-edged sword: a subwoofer with midrange aspirations, or the other way around.
A heavy, straight-sided cone with concentric reinforcing ribs, but also exhibiting the rising response that's typical for mid woofers.
Again, no doubt about the performance up to about 500Hz, but the crossover frequency at 800 Hz for the M2 may be a little too much of a stretch.
In the impedance curve this seems to be confirmed > 2 irregularities between 500 and 1000 Hz.
This may be hair-splitting on my part, but it's an expensive driver (US$ 599,00).
Another step up the price ladder is the Fostex FW405N, as used by Marco Gea.
This woofer shows very low distortion figures in the test by Hobby-Hifi.
Marco crosses the woofer at 600Hz, which makes sense considering the first anomalies at 900 Hz.
This woofer looks like a typical large format sub(bass) driver for hifi purposes.
A really big (475 L) BR enclosure is needed to achieve the lowest -3 dB.
Like most subwoofer drivers, this one is also quite inefficient
In my current apartment -3 dB below 40 Hz is overkill and even undesirable in relation to the neighbours, but also because of room modes.
To quote someone on another forum:
"Keep in mind that "room rise" plays an important role, this tends to start the 12 dB/octave rise around 30 Hz in typical living rooms.
This "room rise" effectively EQ's the VLF response of a loudspeaker system. If one has a loudspeaker system that exhibits flat response to 20 Hz
in an anechoic environment it is going to have a pronounced low frequency response in a typical listening room. Some people like that." > I don't!
Attachments
Last edited:
Hey camplo / all, studio folks in particular.....
Dumb question, but what does near-field and far-field mean in terms of studio monitors?
I've had the impression that in studio-speak, it simply means whether the listening control spot is close to, or far from, the speaker.
That it is an arbitrarily user defined distance, independent of the size of the speaker.
I hope that impression is wrong.... don't really know how i got it....
Because i think most of us speaker builders know and use the technical definition of near-field and far-field.
My technical synopsis is that far-field doesn't occur until the coherent summation of all drivers falls together, and the SPL across the spectrum uniformly falls at 6dB per doubling of distance.
I've been taught critical listening begins with the onset of that technical definition of far field, that any closer listening is very compromised.
Old rule of thumb for the far-field onset, is 3x longest speaker dimension.
So how does this work with close listening, like 1m ...with anything larger than a foot tall speaker?
Can big speakers, that aren't very close to true point source, really be used so close?
Hello Ro808
I use it in a 2 way passive with the M2 horn crossed @ 700Hz. I use a large format 4” CD as opposed to the 2430 ring radiators. The 2216 sounds just fine.
As far as a double edge sword look back to the 2235 and you had almost the same things going on. Smooth enough to work in 2 way 4430 studio monitors but also capable of subwoofer performance.
In my current apartment -3 dB below 40 Hz is overkill and even undesirable in relation to the neighbours, but also because of room modes.
To quote someone on another forum:
"Keep in mind that "room rise" plays an important role, this tends to start the 12 dB/octave rise around 30 Hz in typical living rooms.
This "room rise" effectively EQ's the VLF response of a loudspeaker system. If one has a loudspeaker system that exhibits flat response to 20 Hz
in an anechoic environment it is going to have a pronounced low frequency response in a typical listening room. Some people like that." > I don't!
Well it depends on how you do it. I am using all digital inputs which gives flexibility using multiple DSP settings for the bump filter. I have 3 settings one @ +6db +3db and No bump filter that are adjustable on the fly.
That 12 Db sounds a bit optimistic for room gain as it really is placement dependent but there is no getting away from there will be some added room gain.
With the settings used it depends on low bass content with some music going from +6 to 0 has essentially no effect with others I agree +6 can be a bit much. Also depends on listening levels as it acts similar to a FM to fill in bass at lower listening levels.
Rob
Attachments
Hi Mark,
Well for what i've seen: the max loudspeaker distance allowed for stereo is around 3,5m/4m ( above this you need a center chanel or you have a hole in center) so as the listening position is equilateral triangle this makes far field around those value.
For nearfield it is as close as possible so given depth of big analog desks it vary from 1,2m to 1,5m.
The summation of drivers will vary with design choice and i'm not sure a rule of thumb could be applied but yes with multiple drivers and 'conventional' layout you may need some space.
That said with my conventional 3 ways ( WMT 80cm heigth) i was able to have something usable at 1,5m. Better at 2m though.
Well for what i've seen: the max loudspeaker distance allowed for stereo is around 3,5m/4m ( above this you need a center chanel or you have a hole in center) so as the listening position is equilateral triangle this makes far field around those value.
For nearfield it is as close as possible so given depth of big analog desks it vary from 1,2m to 1,5m.
The summation of drivers will vary with design choice and i'm not sure a rule of thumb could be applied but yes with multiple drivers and 'conventional' layout you may need some space.
That said with my conventional 3 ways ( WMT 80cm heigth) i was able to have something usable at 1,5m. Better at 2m though.
That's correct.
A curvilinear cone not only increases geometrical stiffness, but also improves off-axis response in the midrange.
Attachments
Last edited:
Wow, this got deep into a highly confusing discussion.
First the terms "near" and "far" refer to highly technical aspects of a source. They vary with frequency and they do define the transition from "near" wave interactions that do not propagate very far and hence are not see in the "far" field. These terms - in Acoustics - are very specific and do not mean the same things as used for things like "near field monitors" (all that means is "close (near) listening". The correct term should be "direct field monitors".
What is being discussed here is what is called the direct field, where the sound level is dominated by the direct sound from the source and the reverberant field where the opposite is true. First, we must realize that these definitions only apply to steady-state HF (above fS) signals. Next the major take-away is that as the directivity Q goes up, the ratio of direct/reverb also goes up. This is true in all rooms, no matter where one listens, at the critical distance or not. Hence, a higher Q will always diminish the rooms influence not matter where one is in the room. The critical distance location is not important.
Perceptually, this can be demonstrated with some ease. Toe your speakers in so that they cross some ways ahead of you. Now move closer to the speakers along the normal line between them. As one get closer the sound image will sharpen and collapse to dead center as one gets closer. In my system this effect is quite pronounced. The point at which this transition takes place is going to be very close to the critical distance. The effect is pronounced (much like headphones) and many like it very much. I don't so much, I prefer the ambiance of the room being present not absent.
So high-Q directivity diminishes any rooms effect at any location, that's what makes it so important. But high-Q constant directivity is extremely hard to achieve and is very seldom done in home systems because of this. I do it, and to me, it is by far the optimal way to setup a system.
First the terms "near" and "far" refer to highly technical aspects of a source. They vary with frequency and they do define the transition from "near" wave interactions that do not propagate very far and hence are not see in the "far" field. These terms - in Acoustics - are very specific and do not mean the same things as used for things like "near field monitors" (all that means is "close (near) listening". The correct term should be "direct field monitors".
What is being discussed here is what is called the direct field, where the sound level is dominated by the direct sound from the source and the reverberant field where the opposite is true. First, we must realize that these definitions only apply to steady-state HF (above fS) signals. Next the major take-away is that as the directivity Q goes up, the ratio of direct/reverb also goes up. This is true in all rooms, no matter where one listens, at the critical distance or not. Hence, a higher Q will always diminish the rooms influence not matter where one is in the room. The critical distance location is not important.
Perceptually, this can be demonstrated with some ease. Toe your speakers in so that they cross some ways ahead of you. Now move closer to the speakers along the normal line between them. As one get closer the sound image will sharpen and collapse to dead center as one gets closer. In my system this effect is quite pronounced. The point at which this transition takes place is going to be very close to the critical distance. The effect is pronounced (much like headphones) and many like it very much. I don't so much, I prefer the ambiance of the room being present not absent.
So high-Q directivity diminishes any rooms effect at any location, that's what makes it so important. But high-Q constant directivity is extremely hard to achieve and is very seldom done in home systems because of this. I do it, and to me, it is by far the optimal way to setup a system.
What i was questioning was hopefully very shallow take-off from the direct field discussion.
From many sources i trust, i've heard to get far enough away from a mutli-way speaker to get into its far-field.
Using the layman's definition i gave earlier:
"that far-field doesn't occur until the coherent summation of all drivers falls together, and the SPL across the spectrum uniformly falls at 6dB per doubling of distance".
So to me it's really not a matter of direct field vs reverberant field.
It's just a super simple matter of how far so we need to be from a multi-way to let the speaker act as one. (And the 3x longest baffle dimension has appeared to work in all my builds...indoor line arrays excluded of course)
For instance, i think the test you offered, moving in on toed in speakers for finding the approximate critical distance is a great test.....only providing the found distance is in the far-field.
Because basically it seems very questionable as to whether near field listening is valid.
Too close and i hear individual drivers talk independently. With near-field driver measurements subject to far more minute lateral (same distance) mic movements than in the far field.
I like the Klippel interview Erin put up: Klippel's Near-Field Scanner vs Anechoic Chamber: Discussion with Christian Bellmann - YouTube
About 8 minutes in, is a bit on far-field that matches what i've been taught.
I wish it had also gone deeper into multiple driver's phase summation problems in the near field.
It's really cool the science behind the Klippel' Nearfield Scanner....way over my head though...i'd kill for your math ability
From many sources i trust, i've heard to get far enough away from a mutli-way speaker to get into its far-field.
Using the layman's definition i gave earlier:
"that far-field doesn't occur until the coherent summation of all drivers falls together, and the SPL across the spectrum uniformly falls at 6dB per doubling of distance".
So to me it's really not a matter of direct field vs reverberant field.
It's just a super simple matter of how far so we need to be from a multi-way to let the speaker act as one. (And the 3x longest baffle dimension has appeared to work in all my builds...indoor line arrays excluded of course)
For instance, i think the test you offered, moving in on toed in speakers for finding the approximate critical distance is a great test.....only providing the found distance is in the far-field.
Because basically it seems very questionable as to whether near field listening is valid.
Too close and i hear individual drivers talk independently. With near-field driver measurements subject to far more minute lateral (same distance) mic movements than in the far field.
I like the Klippel interview Erin put up: Klippel's Near-Field Scanner vs Anechoic Chamber: Discussion with Christian Bellmann - YouTube
About 8 minutes in, is a bit on far-field that matches what i've been taught.
I wish it had also gone deeper into multiple driver's phase summation problems in the near field.
It's really cool the science behind the Klippel' Nearfield Scanner....way over my head though...i'd kill for your math ability
Doesn't this depend on the coverage angles/directivity versus the distance between 2 speakers?
Personally, I like to listen 8 to 10 meters away, especially at higher SPLs.
Last edited:
Thanks Rob!
I really like your interpretation of the M2 (theme).
I suppose you're using 245. drivers, with Truextent?
Last edited:
Earl is right it is confusing.
When i talked about near/mid/far field i talked about the way differents studio monitors are sometimes called/defined.
Big mains are farfield, nearfields are ns10/1031/... ( ~30liters box) midfields in between.
As the discussions turned about drivers sumation i thoughts it was what Mark was refering to.
The name choosen are not wise i agree and Earl's proposal make more sense ( and wont lead to be mixed with acoustic definition of them) but those are the habits i was exposed to.
About critical distance from the 5 professionals acousticians i worked with ( or been in contact with) they all locate the sweetspot there. I know it is variable with frequency but i understood they considered 1or 2 khz as the freq of interest to define it.
If there is more to it or i am wrong in my understanding i'm open to be corrected.
Mark there is no point to listen above critical distance ( in the acoustic far field) in studio environnement: the last thing you want is to have the own room behavior to dominate what you are listening to. You want it to be part of what you listen but you want to be the most of what you listen to be close field ( below critical distance, sound of loudspeakers dominate).
But you may encounter some control room which are designed to have critical distance and the point where multidrivers loudspeakers merge at the same physical place ( which make sense as no one is supposed to make critical listening above the console).
For closefield monitors critical distance is supposed to be ok as it was defined for the mains which are usually located far away and RT is most of the time low ( 0,2/0,3 seconds).
Ro808,
Not from what i've seen. The limitation was presents in the control room i built ( Lafont design from mid 00, absorbent front, diffusing backwall overall very damped with ATC scm110a ) when we played with the monitors location before finalising the built or the Omega A control room ( very big room with TAD TH/TD and et703, 2x TAD 12" each L-C-R with more than 4m between L/R and subs 6x 15"...).
When you talk of 8/10m is it indoor or outdoor? And i suppose this is for live events?
I've found things to be a bit different outside and like you i like this kind of distance but it is so different to the rendering indoor and at this distance i find the experience to be more about the physical feelings of a big soundsystem pushed than correct stereo rendering.
When i talked about near/mid/far field i talked about the way differents studio monitors are sometimes called/defined.
Big mains are farfield, nearfields are ns10/1031/... ( ~30liters box) midfields in between.
As the discussions turned about drivers sumation i thoughts it was what Mark was refering to.
The name choosen are not wise i agree and Earl's proposal make more sense ( and wont lead to be mixed with acoustic definition of them) but those are the habits i was exposed to.
About critical distance from the 5 professionals acousticians i worked with ( or been in contact with) they all locate the sweetspot there. I know it is variable with frequency but i understood they considered 1or 2 khz as the freq of interest to define it.
If there is more to it or i am wrong in my understanding i'm open to be corrected.
Mark there is no point to listen above critical distance ( in the acoustic far field) in studio environnement: the last thing you want is to have the own room behavior to dominate what you are listening to. You want it to be part of what you listen but you want to be the most of what you listen to be close field ( below critical distance, sound of loudspeakers dominate).
But you may encounter some control room which are designed to have critical distance and the point where multidrivers loudspeakers merge at the same physical place ( which make sense as no one is supposed to make critical listening above the console).
For closefield monitors critical distance is supposed to be ok as it was defined for the mains which are usually located far away and RT is most of the time low ( 0,2/0,3 seconds).
Ro808,
Not from what i've seen. The limitation was presents in the control room i built ( Lafont design from mid 00, absorbent front, diffusing backwall overall very damped with ATC scm110a ) when we played with the monitors location before finalising the built or the Omega A control room ( very big room with TAD TH/TD and et703, 2x TAD 12" each L-C-R with more than 4m between L/R and subs 6x 15"...).
When you talk of 8/10m is it indoor or outdoor? And i suppose this is for live events?
I've found things to be a bit different outside and like you i like this kind of distance but it is so different to the rendering indoor and at this distance i find the experience to be more about the physical feelings of a big soundsystem pushed than correct stereo rendering.
Last edited:
Im aiming for what I know, now, as a large direct field, so that hopefully at 1 meter the direct sound will strongly over power the reverberation field. This is the reason why I never let go of the KA aspect, regarding the crossover from the midwoofer to the horn...the perception of location per frequency is an issue as well, also supporting a lower crossover
So looking at Mark100 point about summation...I personaly don't believe there is any science, per say, around the idea of a listening distance based off of driver diameter or baffle width, rather, our ears have different levels of localizing ability depending on frequency, which the trend seems that the lower the frequency the less accurate it is...( now I wonder if thats the rooms fault to begin with) and KA is absolutely a factor, too which I'd love to get the ka of the 15" down to 0.5 though being to get below 2 is a blessing anyways.
My current 1+4+12 system is 1 meter away and I don't feel like there are any issues of summation that are experience ruining. The 1 and 4 are very tight. The 12" crossed at 130hz to the 4" never made me feel some type of way...though I feel like I can tell that the bass isn't coming from where the tweeter is, its not what I would call experience ruining? With that said I bet the big popular coaxial monitor with the 15" (goliathan or something rather) would be night and day at 1meter compared to my system
For my usage in particular, I'd sacrifice "summation" for accurate FR, if I want summation then I could just move back. With that said, Ive done all I can to create as much cohesiveness at a close listening position as Ive stated above (Low KA at crossover, tight ctc) if not obvious by trying to get a great amount if bandwidth out of a tweeter lol
Last edited:
Krivium, nice summary and separating the parts of the discussion.
Yes, i can easily see "there is no point to listen above critical distance ( in the acoustic far field) in studio environnement"
Here's a link that explains what i was talking about better:
Far-field Criteria for Loudspeaker Balloon Data
Admittedly, it is more for pro-sound, like building EASE data.
But i figure the principles are the same for all speakers. And I've heard the 3x rule of thumb many times over the years from varied sources.