Right, none of us have anechoic rooms, but I guess there can be quite some variability in the level of reflections. A studio control room can be quite variable in terms of the amount of reflections at LP.
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Perceptual Effects of Room Reflections
- Thread starter amirm
- Start date
As in all things too much a good thing becomes a bad thing. Everything in moderation.
Actually right now my reverb times fail the standard for reverberations times. Perhaps a little too dry.
So yes a mono centered source sounds different. But what’s funny, and I read it recently, people prefer mono out of a stereo set to a single mono speaker.
I think it’s the reflections. They create some phase differences and make things sound more spacious. Instruments spread out of that center bubble.
Apart from panels, I guess just toe in or toe out to ameliorate this tonal change.
I wish there were an easy way to compare the tonal difference aurally in a program or file. That way we could actually know what the change is and tune through various methods how we each like this frequency range to sound.
For example right now i’m enjoying a very damped and perhaps even overdamped environment judging by my latest reverberation time ITU standard between 100-300Hz.
I’ve been controlling that with an excess of panels with varying degrees of success.
As Bjorn indicated above in his post. I have been learning the orientation of the panels to the monitor matters.
However after some time I could try to put diffusion there.
Perhaps toe out. Change the soundstage and reflections. The that out for a few days. Maybe even take notes.
It really does get into art at some point.
There are quite a few threads about crosstalk cancelation to read at ASR.
Cars-N-Cans
Addicted to Fun and Learning
I think strictly based on evaluation of tonality in a relative sense during controlled listening in mono its correct. My experience is the auditory center does a lot of interpolation when there are two speakers, and it seems the more information that is available, the better the job the auditory center does at perceiving the image and reconstructing the sound. Small tonal imperfections can also potentially be filled in if there are two speakers and additional reflections that help the overall response sum to be perceptually flat. My understanding is just having one speaker deprives a lot of that information, thus making it easier to subjectively judge tonality on its own in a controlled listening situation. Edit: There is definitely a difference in sound as you go up from mono, but my take is that its more due to imaging than the actual tonality of the speakers themselves. As stated two speakers in mono can sound vastly different than just one. But objectively its still important to try to find ways to segregate them in terms of evaluation even though the tonality and imaging are intertwined, and in that regard Toole I think did a reasonable job with the approach of using single speakers for evaluation.
Last edited:
Cars-N-Cans
Addicted to Fun and Learning
There's nothing really to compensate for at the mixer for cross-talk, other than the 60's approach of simply panning things hard left and right. I was watching some of the videos from the last Munich audio show to see what was there and one thing that seemed to pop up was older classical recordings, and it was perplexing as to why they were using them until I listened to them directly. The older recordings have things panned to much greater extremes than modern classical recordings which try to approximate (or just simply record) the actual orchestra as it is. In a sound demo, this will give an artificial sense of having a more spacious sound stage than you would really get. I guess they feel that the subjective value exceeds what the older recording loses in terms of fidelity, even though some are still quite good by today's standards.
For XTC, the corrections are applied within the system, and not from mixing. Mixing can help, but that is to enhance the subjective perception of the recording, and not deal with XTC per se. If you were to mix on an XTC equipped system, I would think there is a good chance you'd end up with recordings that sound myopic closed-in on conventional stereo setups. Basically the opposite effect when going back down to regular stereo. On my setup, I do have to compensate for the head shadowing and the reduced SPL that results from about 1 kHz on up. It gives a strange looking measurement with an elevated treble response that's inversely proportional to my specific HRTFs, but is perceptually neutral. However, if I listen through the measurement mic using IEMs to music, the response in the bass and lower midrange is correct, but it gets screechy bright above that due to the fact that the mic records both speakers simultaneously. While there have been various attempts, I don't think its something you would want to do as it would be a mixed bag for many listeners. Some it would help, others not. An example of "not" would be typical pop recordings that are mixed to sound good on things like inexpensive headphones, car stereos, and in-ceiling systems at restaurants.
As far as the stereo recording format itself being "flawed", I don't think it is fundamentally. Done correctly, its the most accurate method, better than multi-channel setups I have heard. But the huge caveat is that its the most difficult to get right since you only have two speakers, and both you and the room have to be integrated into the response to get the correct transfer characteristics, or it doesn't work. In that regard, multi-channel setups make more sense for general use since there is more flexibility with having multiple channels. On the flip-side, proper two-channel setups actually allow the sound sources in the recording to be perceived as the origin of the sound, and not the speakers themselves. This gives a unique experience in that the contrast is jet black, and the sound immersive, vivid, and natural. There's no real sense that you are actually listening to speakers. This is something I don't get out of headphones. Maybe there are some headphones that do get there, but I have not had a chance (nor probably ever will) to sample things like the HE-1. But with speakers there are so many variables, and so many obstacles to overcome, which is why I think it's on a trend towards being relegated to relative obscurity in favor of multi-channel speaker setups and binaural methods for headphones and IEMs like what Apple has.
But, all of this is quite far from the original topic on the face of it, but in some ways its not since the reflections are both a desirable and undesirable characteristic at the same time, depending on how much and when you have them in relation to the direct sound.
Adi777
Addicted to Fun and Learning
- Joined
- Apr 14, 2022
- Messages
- 690
- Likes
- 461
Is stereo "flawed" in a general sense, or only when it is misconfigured, incorrectly combined with the acoustics of the room?
Isn't it better to listen to multi-channel music and concerts on a multi-channel system, such as Atmos and / or Auro3D, and stereo recordings on a 2.0 / 2.1 / 2.2 / 2.4 system?
Of course, if we have a place and enough money for two systems.
Isn't it better to listen to multi-channel music and concerts on a multi-channel system, such as Atmos and / or Auro3D, and stereo recordings on a 2.0 / 2.1 / 2.2 / 2.4 system?
Of course, if we have a place and enough money for two systems.
Cars-N-Cans
Addicted to Fun and Learning
I would say stereo sound reproduction is flawed in the sense that the conditions to get it to work properly are something you cannot attain in the vast majority of situations. For proper imaging, at a minimum in the region where spatial cues in the recording reside, each ear needs to exclusively hear each respective speaker, and not the opposing one in tandem. Some listening configurations can approach this (e.g. carefully configured mixing studios and control rooms), but its not something you will get in a typical domestic listening environment. I think its one main reason speakers in a two-channel setup need to be so good, is that rooms can just be so bad acoustically. You are already going up a hill to begin with. This is why the multi-channel systems offer an advantage in domestic listening rooms is that there are additional speakers that can be used to help with imaging by carrying additional specific cues. These will be somewhat artificial, though, since you are basically using multiple speakers and channels to emulate the location of a sound source. It still can be quite close to what you would hear with proper processing, and less room sensitive. With stereo and proper conditions, the auditory center can be used exclusively to reconstruct the locations of the sound sources instead, which is much closer to what we will get in real life. But then both you and the room become part of the equation, and this is very sensitive to even small errors.
tuga
Major Contributor
2-channel stereo also fails because all sound cues are generated by two sources positioned in front of the listeners, and some of them should be coming from the sides or behind her/him. The most obvious example is the clapping at live events, which in 2-channel stereo is coming from the "soundstage".
Cars-N-Cans
Addicted to Fun and Learning
I guess if you want to hear that stuff. Most live music is in front of the listener, though.
tuga
Major Contributor
If it's in the recording, there's no escaping it. And it detracts from the realism.
But that example was only used for illustration, reverb and envelopment coming from the front in orchestral music is more damaging.
Last edited:
Cars-N-Cans
Addicted to Fun and Learning
With conventional stereo and a more 2D soundstage, yes. However, for immersive systems its not as much of a limitation since only the late reflections and reverberations will be mirrored from their true origin in that situation. The direct sound and early reflections that would be associated with the instrument itself are correctly conveyed. It doesn't necessarily sound wrong, but the imaging stops at the extremes of the listening position. Yes we could fix this detail with multi-channel recording and get that last bit of realism, but then we introduce yet another system for recording music likely to be forgotten about. However, with 2-channel binaural systems all of the two-channel recordings that contain both ILDs and ITDs are compatible, and the effect is more than adequate for a good if not excellent sense of immersion and engagement. Much better IMO than having to wait for the next "X" formatted music recording to come out to enjoy a system, only then to be phased out because people lose interest.If it's in the recording, there's no escaping it. And it detracts from the realism.
But that example was only used for illustration, the lack of reverb and envelopment in orchestral music is more damaging.
Secondly, even with two-channel systems this can be addressed via convolution with suitable HRTFs. The brain doesn't care how many speakers you have, it only cares about the transfer function, and with suitable processing imaging is in principal possible behind the listening position. But, just like multi-channel, this complicates things, and something I have not found to be much of a limitation for music reproduction just using what's in the recording.
Edit: Doh! Can't type...
tuga
Major Contributor
My comments refer to 2-channel 2-speaker stereo only. I don't like listening on or wearing headphones.
Imaging and soundstage is only a part of recorded music reproduction and one which I only treasure when listening to classical music, jazz and traditonal.
Musically it is of lesser importance in my view and I would rather not upmix 2-channel to a more immersive setup because other aspects of sound will be affected negatively.
As with anything in audio, ultimately it's down to personal preference and budget.
Reproducing the original soundfiled in domestic settings is impractical or perhaps impossible, and the stereo illusion requires some degree of abstraction from the listener. I find that 2-channel is enough for my needs, I am not an imaging/soundstaging devotee.
Cars-N-Cans
Addicted to Fun and Learning
I have exactly the same view in that music is also an art, and we want to leave room for the production of music as well. For me a two-channel BAL system provides a nice compromise to get the most out of a recording.
You have to imagine to sit in a lounge.If it's in the recording, there's no escaping it. And it detracts from the realism.
But that example was only used for illustration, reverb and envelopment coming from the front in orchestral music is more damaging.
Yes. Let me offer an anecdote. I was listening to a solo cello recording in a discrete multichannel recording (Channel Classics - 17198) and was enjoying the solid presence of the instrument in the center within a barely noticeable but pleasant ambiance. Then, just at the end of one of the suites, I clicked to instantaneously switch to stereo (on a rare player that permits it) and was shocked by the compression of the space as all the ambiance was sucked back behind the instrument. Especially notable was with the decay of the last note which had before "hung in space." At switching to stereo, it was reduced to a focal buzz.
Take note that one of the main ideas behindLEDE or LEDE/RFZ was actually to emulate the sound of the best concert halls in the world.If it's in the recording, there's no escaping it. And it detracts from the realism.
But that example was only used for illustration, reverb and envelopment coming from the front in orchestral music is more damaging.
That's simply not possible with multichannels playing at the same time due to a high level of polar lobing, combing and high gain specular energy.
True realism from multichannel can only be achieved if one or two speakers are used simultaneously. For example the use of one or two rear channels to let you experience a door is being opened behind you. Combined with recording from a special in ear mic, this was demonstrated decades ago. According to the listeners it was spooky realistics. However, this type of multichannels lost the commercial fight and we ended up with Dolby digital, DTS, etc. instead, and which is basically only a gimmick and achieves no realism.
This is not an absolute. There are thousands of discrete multichannel recordings.
In theory, certainly.
Cars-N-Cans
Addicted to Fun and Learning
This is why I went towards binaural. For years stereo just sounded like nice speakers playing music, so I lost interest. I think no matter which way you slice it, stereo in its native form just lacks the realism and engagement possible with other techniques
To be fair there probably are stereo systems that buck this trend with careful setup…
Binaural works but the library is tiny.
Similar threads
