That's a well damped room! You don't find it too dry?
Interesting that we both started out with that big peak between 1K-2K. Similar room materials, perhaps? Mine looks like this
Would like to flatten it a bit more, still.
I believe that more rooms look like our starting points than most folks want to admit. Might have a little to do with why "flat is not correct."
Missed this little exchange in this thread until now, that's a very live room indeed before treatment!
Out of interest I've just measured my current listening room - a fairly small, far from optimum listening room, 4.8 metres wide and 3.45 metres long.
There are two sofas, curtains to the left hand end, a rug on the floor between the speakers, some miscellaneous furniture, and a door on the rear of the right side wall. Without any treatment I found the room tolerable but a bit too reverberant.
The right hand wall and the right half of the rear wall straddling the door are both largely bare and there is a noticeable slap echo in the room because of it. Some time ago I decided to try hanging a blanket like rug over the right rear door in the middle of that very bare corner which covers about 2/3 of the door and noticed a big improvement in slap echo and overall acoustics.
In the attachment below the red curve is the untreated room, yellow is with the "blanket" hanging on the door. Quite a change indeed from one small change to the worst part of the room, and I'm quite surprised by just how flat the RT30 is, staying between 0.38 and 0.45 over most of the spectrum above 300Hz.
What's interesting though is despite being a small room and me perceiving it as being too live compared to previous listening rooms I've had, the peak RT30 was still only about 0.5 - well short of your 0.85, so I can only imagine what that sounds like...
I think I'd like to get the RT30 down to about 0.3 but I don't think it's going to happen in this room with "mutually acceptable" changes 😀
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Doug,
Do you have something useful to add, or are you just sniping from the sidelines ?
I have never said DBT's are inherently flawed, I said that using them for tests for which they are not appropriate or meaningful is flawed. Big difference. Sheesh.
My room is slightly larger at about 5.3m long X 4.0m wide X 2.5 high. I've got 2 big bookshelves in the rear corners which seems to help alot. There are also a fair number of other surfaces which help diffuse the sound. (Chairs etc)
The floor is hardwood and I only have a relatively small throw rug of 1m X 2m on the floor. It seems surprisingly well behaved. (this is with 180ms window... what setting should be used for a valid comparison?)
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I'm not familiar with the software you're using to take your measurement, so I'm not sure how any measurement options might compare to those in ARTA.My room is slightly larger at about 5.3m long X 4.0m wide X 2.5 high. I've got 2 big bookshelves in the rear corners which seems to help alot. There are also a fair number of other surfaces which help diffuse the sound. (Chairs etc)
The floor is hardwood and I only have a relatively small throw rug of 1m X 2m on the floor. It seems surprisingly well behaved. (this is with 180ms window... what setting should be used for a valid comparison?)
The measurements I took didn't have any explicit windowing enabled, I just had the start maker set to just before the first impulse. FFT size was 256k in Periodic Noise mode, (although I tried swept sine and the result was nearly identical) sample rate 96Khz, there isn't much else you can change.
I'm only using the Demo version of ARTA so you could try using it yourself in your own room to get a direct comparison with the other software you're using if you're curious 🙂
And then what about mic placement? Where should it go? I put mine right in the center of the room - center height, too.
The starting point was very bad. Bare walls and ceiling, nothing else but the speakers. There was carpet on the floor, which by ear was already a big help. I built my own room treatments - see here: http://www.diyaudio.com/forums/everything-else/179901-making-pegboard-acoustic-panels.html#post2449920
The starting point was very bad. Bare walls and ceiling, nothing else but the speakers. There was carpet on the floor, which by ear was already a big help. I built my own room treatments - see here: http://www.diyaudio.com/forums/everything-else/179901-making-pegboard-acoustic-panels.html#post2449920
The docs for ARTA suggest that for measuring Reverberation time the microphone position should be at least 1 metre from any reflecting surface, and also not be "too close" to any source (speaker) position, (giving an equation to calculate what represents too close based on room volume) and that the microphone should be omni-directional.
For a 2 channel set-up this suggests that the listening position is probably the best place to measure, but brought away from the nearest wall or object by at least a metre, if necessary. This is what I did - my listening position is of necessity only about half a metre from the wall behind me, so I set the measurement position 1 metre in front of the wall but otherwise at the same height and lateral position as the normal listening position.
I prefer rooms with carpet for acoustics too, but although I didn't remember to mention it my current room is laminated wood flooring. Only about 40% of the floor area is visible though, due to a 1.5m x 2m rug and the footprint of various other furniture and objects.
Yeah, I remember reading that in the ARTA docs. Which is why I placed the mic as far from any surface as I could.
I really wanted to do pistol shots, but in this county you need a permit even for a starter pistol. Sheesh!
I really wanted to do pistol shots, but in this county you need a permit even for a starter pistol. Sheesh!
A fast moving discussion...stay away a few days and see what happens.
Actually, I was giving a synopsis of what Linkwitz was saying, since people seemed to have different interpretations of it.
I do tend to agree with his emphasis on the direct sound, and others have had similar views on speakers creating phantom sources at different positions. I believe Holman and THX used similar thinking for surround re-EQ.
David S.
"Dave" may have been referring to the user "dlr".
I find it interesting that no one has referenced Sean Olive's blog post and the corresponding AES keynote presentation, which has relevant points: Audio Musings by Sean Olive: The Subjective and Objective Evaluation of Room Correction Products and https://docs.google.com/fileview?id...mUtNDEyNC00ZDcyLWEzZTAtMGJiODQ1ZTUxMGQ4&hl=en
Nothing about this discussion is obvious.
I Listen to recordings of classical music.
Instruments and ensembles, whether a piccolo, a piano,or a chorus all produce a complex waveform which is registered by a mic, (the size and shape of the instrument or ensemble is not relevant, what is relevant is the waveform they present to the microphone), and run through a recording process. The recorded waveform passes through my electronic system to my speakers which reproduce it with minimal nonlinear and linear distortion.
It sounds very good, in mono one speaker, mono two speakers, and stereo. Instruments and voices have good timbre like they do live. (They do not sound at all "synthesized" - synth music sounds synthesized). I have a broad sweet spot and moving off axis doesn't change stereo imaging significantly.
But, but it doesn't sound like the performance. I'm shovelling a symphony, an opera, a string quartet, Thomas Hampson and a grand piano, into a room 23 ft long. This plane doesn't fly. It's a beautiful plane but it only taxis up and down the runway.
I have four ways of modifying this experience: move the mains together and do cross talk cancellation; go to the near field; use earphones; or "enlarge" the listening space.
I like to move around so I'll choose the latter.
Hmmm. Well on classical I don't get much of the "musicians in my living room" sound. On some chamber music recordings, yeah. Mostly it's a window into the recording venue. It even sounds like that in the next room. It's an effect I enjoy.
Pop and rock recordings are all over the place.
Pop and rock recordings are all over the place.
Daisy, Daisy, give me your answer, do. I'm half crazy, all for the love of you. It won't be a stylish marriage. I can't afford a carriage. But you'll look sweet upon the seat of a bicycle built for two …
I find that the more instruments that there are and the larger the venue the more difficult it is to "suspend belief". But is this really surprising? I did a dry recording of a solo piano once and when played back in my room the effect was simply that there was a piano in my room. It is quite astonishing. But a large orchestra! I've heard better and worse, but never anything that is truely convincing. Thats just the limitation of the medium. Fortunately for me large ensembles are not my thing and stereo works very well for what I listen to. I truely sympathize with those who limit their listening to large ensembles because I don't think that full satisfaction will ever be achieved. I mean even with 3D or panographic wide screen, I still know that I am in a theater not on some remote planet. What can you expect?
There's a vinyl recording of the original from around 1964. Kubrick didn't like the nasal sound and so he didn't use it in the movie. Hal has a human voice.
I worked in that department at Bell Labs three years later. The head was a Hungarian. We used to joke all the speech synthesizers had a Hungarian accent.
I suppose human sound production from mouths comes about as close to being shaped more like a loudspeaker than any instrument I can think of. From down the hallway, I do sometimes mistake voices on the radio for real people.
Perhaps there's a new international measure of hifi quality there: how far down the hallway do you have to be to believe you are listening to a real X in your music room. Measuring in meters makes it more scientific, of course.
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It is NOT the limitation of the medium. It is mostly a limitation of the speakers and to some extent the room. I know, I've heard it. It was one of the most surprising experiences of my life.
It's not going to happen with 3 cubic foot box speakers in the typical living room.
But it is NOT the medium - amazingly - it's far better than most people expect.- Status
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