Scott I don’t think you understand at all actually
I am not advocating using sTIpa measurements rather, the root of them is the MTF measurement which is a measure of resolution or depth of modulation, just like it is in optics an MTF is an indicator of resolution.
One can take an MTF measurement alone too at a frequency of your choosing which is what I am talking about.
Just like with optics, as you corrupt the signal, you reduce the modulation depth and resolution.
If you look at a Cumulative Burst Decay waterfall, you can also see the late stuff that reduces modulation depth.
If you wish to believe that reducing the modulation depth is required or better subjectively than how the signal starts out that’s fine because our argument is over, but consider that NO other part of the chain “gets more faithful to the signal” by reducing its resolution, period.
Tom
I am not advocating using sTIpa measurements rather, the root of them is the MTF measurement which is a measure of resolution or depth of modulation, just like it is in optics an MTF is an indicator of resolution.
One can take an MTF measurement alone too at a frequency of your choosing which is what I am talking about.
Just like with optics, as you corrupt the signal, you reduce the modulation depth and resolution.
If you look at a Cumulative Burst Decay waterfall, you can also see the late stuff that reduces modulation depth.
If you wish to believe that reducing the modulation depth is required or better subjectively than how the signal starts out that’s fine because our argument is over, but consider that NO other part of the chain “gets more faithful to the signal” by reducing its resolution, period.
Tom
Repeat after me,
You can control the speaker you can't control every room it's used in therefore...You can control the speaker you can't control every room it's used in therefore...You can control the speaker you can't control every room it's used in therefore...You can control the speaker you can't control every room it's used in therefore...
You can control the speaker you can't control every room it's used in therefore...You can control the speaker you can't control every room it's used in therefore...You can control the speaker you can't control every room it's used in therefore...You can control the speaker you can't control every room it's used in therefore...
Hi Tom,
Actually I meant that understood your premise of a corrupted signal - that I understood what you were arguing for, but not in context with STIpa.
Graci! That's the tie-in I was missing. 🙂
Please note: I read your post and never really got that at all - after several readings. 😱
Post 60:
http://www.diyaudio.com/forums/mult...rns-no-drawbacks-no-issues-6.html#post3622802
It starts with STIpa, makes comparisons, but doesn't mention MFT until much further down. Honestly, to me it appears as if you are making an argument with regard to Intelligibility and the STIpa as a measure of that - with a contextual carry-over from commercial sound to a domestic setting.
Once you do mention MFT, it really appears to be a "build-up" for STIpa.. MFT link first, STIpa link next.
Combine that with the prior statements on STIpa pretty much reads like support for STIpa's use (or bastardization). 😱
It's why I responded in 3 parts originally:
http://www.diyaudio.com/forums/mult...rns-no-drawbacks-no-issues-9.html#post3624677
I should have just made the 1st response.. 😱 but I didn't know that. 😱
-just "running down a rabbit hole" on intelligibility. 🙄
(..you do get the irony of that, right?) 😀
Going to go out on a limb and say that vocal illegibility probably has everything to do with this. (-: It's funny but PWK used to say: It's easy to test a room, have someone talk in it. Not far to go from there to "the speaker should not light up the room any more than it has to" Wishing that guy was still around. Like to say hello.
Hi Tom, (again) 😱
Lets go through a logic sequence based on information I've already provided:
1. Reflections add-in as a noise floor (or the "late stuff" on a room CSD).
2. The noise floor caused by reflections reduces the modulation depth from direct sound.
3. Direct sound has the quality expressed as Intelligibility.
4. Intelligibility specifically references the ability to understand the content of that direct sound (particularly with respect to dialog).
5. The improved ability to understand direct sound (dialog) is by all reasonable use of the word: a particular "measure" of resolution. (..ie. are you more able to resolve the dialog from the loudspeaker, or less?)
6. Intelligibility is improved with reflections (..within a time window common to the small room context). *A well observed/studied fact*.
7. Resolution (of Intelligibility) is improved with an increased noise floor (to an extent common enough in a small room acoustic).
8. When the modulation depth is *lowered* (by reflections and their increased noise floor), resolution (of Intelligibility) is increased.
-period. 😉
..and there are many other examples as well.
In the context of the recording itself reverberation (NOISE) is used all the time to set-back images giving it's location a higher degree of accuracy in the depth plane, both location and character. Without it you'd have images "riding on top" of each other unless they were each lateralized in a stable "line".
..how about dither? (..and not simply in the context of audio.)
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6. Intelligibility is improved with reflections (..within a time window common to the small room context).
You leave out one thing. Tom's designs are not doing away with reflections, but minimizing them. I can't think of any source short of headphones (that many find preferable to speakers BTW) that doesn't already have more reflections than we need. And that is the whole ball of wax. It's not that these speakers would eliminate reflections at all, just reduce them and that can only help in the vast majority of rooms. I have decades of empirical dealing with this to rely on I'm not just pooping it out.
You leave out one thing. Tom's designs are not doing away with reflections, but minimizing them. I can't think of any source short of headphones (that many find preferable to speakers BTW) that doesn't already have more reflections than we need. And that is the whole ball of wax. It's not that these speakers would eliminate reflections at all, just reduce them and that can only help in the vast majority of rooms. I have decades of empirical dealing with this to rely on I'm not just pooping it out.
Oh yeah, lets put the icing on the cake here. If you want the best vocal intelligibility, put on headphones to eliminate room reflections. Like the FBI does when they want to hear who's getting whacked Bwahaaahaaa !!!!!
Is this to say that early reflections will help cut through an otherwise crowded room based noise floor as this sounds like a compromise of sorts. I believe that reducing early reflections is good for intelligibility, at least when the 'bigger picture' is being addressed.
I think the key issue here concerning reflections is that they are already built into the recording, except of course for line in electronic sources. When you hear someone speak into a mic, you are already hearing the room about them. This effect increases exponentially with distance from the source. If humans and for that matter all acoustic sources had a "line out" well then we would need extra reflections from the room till then, minimising them when reproducing is probsably the next best bet (-:
Many recordings have little noticeable reverb and the sources are artificially placed in space. I feel that removing the listening room makes the reproduction of some recordings sound more like an outdoor thing (and not harming intelligibility).
In such cases I can't see adding early listening room reflections as being a good idea. Late reflections, maybe.
In such cases I can't see adding early listening room reflections as being a good idea. Late reflections, maybe.
Yes, late reflections. If diffuse, they help add a sense of space (for me, anyway). A room can be too dry.
Reflections may or may not aid intelligibility. I can see how they would via an analogy to communications theory. The information bandwidth of a channel increases with its signal to noise ration. A matched filter receiver for a channel with multiple paths (possibly due to reflections) can be made by summing the input at various delays corresponding to the delta path lengths so the reflections add in phase. I suppose the ear/brain can do this, if it has to. Would you want to force the ear to have to do this to enjoy music?
Late reflections are always good for spaciousness, but it is simply not true that reflections improve intelligibility. There are cases where a few, mostly one, reflection can improve intelligibility, but in general reflections reduce intelligibility. Just think about listening to speech in a highly reverberant room - the intelligibility is very low.
One does have to keep in mind that intelligibility is not necessarily the same thing as good perception of sound quality, although, like Tom, I believe that it is a factor, but clearly not the whole story.
One does have to keep in mind that intelligibility is not necessarily the same thing as good perception of sound quality, although, like Tom, I believe that it is a factor, but clearly not the whole story.
The only thing the experts in this field are saying is that:
Reflections, actual reflections, from ONLY the direct sound it's produced from, and only when highly correlated (near time of a small room context) - improve intelligibility. And,
Direct sound from *other sources* and reflections from those other sources, lower intelligibility.
Room noise (or *other sources* of sound), is always going to be present in some manner so there is no real set of definite instructions on "optimal" for any given situation when balancing the two opposing conditions (..at least not that I'm aware of).
Honestly, all the experts are saying with respect to this is that it increases loudness and the louder it is (as a net result) the more intelligible it is (..presumably to a point). Always keep in mind the context of those reflections though.
..That's not what the actual experts in this field have found. Read Toole's synopsis. Look at the underlying research from that.
-or have you given-up on the notion of scientific research? 😉
What's the correlation of those reflections in a "highly reverberant room"?
What's the amount of other noise in the room?
Is the speech exciting the room in a manner other than reflections?
Clearly intelligibility plays a roll in the perception of good sound quality.
It's more of a "subset" component, and even a limited one at that if we confine it to the more narrow "dialog" definition.
Still, it is specifically referencing the definite character of resolution.
But yeah, by FAR not the whole story to overall good sound - or even accurate sound (as far as we can define that objectively).
I've just read that chapter in Toole and Scott is correct about the research results. Toole says, among other things, that early reflection have the same effect as increasing the direct sound level. My conclusion that we can eliminate early reflections in hifi without fear of losing intelligibility, thereby enjoying better imaging, simply by compensating with the volume control.
That makes more sense to me than faulting Synergy horns for their directivity.
That makes more sense to me than faulting Synergy horns for their directivity.
The logic sequence was designed specifically as a response to his particular post. 😉
My whole point on the directivity vs. reflection issue (..actual reflections), is that they are largely a "red herring". They rarely matter in our context, and surprisingly they can sometimes be beneficial.
What really counts is the direct sound itself (in this context).
If someone produces a directive design for a small room use (..which isn't Tom), then they should be looking at a myriad of factors as to improved performance relating to their product's direct sound - which might well include directivity.
..yeah, this is really more of a long tangent based on Tom's notion of producing an objective measure for resolution. 😱
Actually I think the Synergy horns should be applauded for the directivity in combination with their other virtues - specifically for their intended use and also in the context of ambiophonics for home use.
..makes me wonder if Tom has even tried ambiophonics with his designs. 😱
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