Originally Posted by dynfan
In fact I see many people build amazing systems that can often cost in the tens of thousands of $$$ and yet their room is completely untreated...
There is nothing wrong with an untreated room. If it is an empty room, sure, that is a problem. But in typical rooms there are furnishings and sufficient amount of them does a very good job of reducing problematic late reflections. Early reflections on the sides can actually be beneficial. Floor reflections as I noted should be dealt with but since timbre changes there occur above 500 Hz, simple carpeting with good padding will do the job. Here is a formal study of how techniques like this work very effectively:
We see how addition of standard furnishing lowered the (late) reflections, getting them to the target we want (lower graph). And how on the average, standard western living rooms are more or less there. Here is Dr. Toole's on the above experiment:"Adding some functional storage and display cabinet and bookcases (no significant absorption but a lot of scattering) dropped the RT and eliminated most of the “empty” sound in the room. The scattering devices were redirecting more of the sounds into the carpet, making it work harder. Bringing in the rest of the furniture and some drapes finished the task. The drapes were chosen to be acoustically effective: heavy cotton with lining, pleated to less than one-half fabric length, and hung 4 in. (100 mm) from the wall so they would function at lower frequencies. The room sounded utterly “normal”; conversation was very comfortable, and reproduced sound, then in stereo, was excellent.
It was in this room that experience was gained in understanding the role of first reflections from the side walls. The drapes were on tracks, permitting them to easily be brought forward toward the listening area so listeners could compare impressions with natural and attenuated lateral reflections (see Figures 4.10a and 8.8). In stereo listening, the effect would be considered by most as being subtle, but to the extent that there was a preference in terms of sound and imaging quality, the votes favored having the side walls left in a reflective state. In mono listening, the voting definitely favored having the side walls reflective."
And the following from a presentation from him:"The amount of reflected sound will alter impressions of spaciousness and reverberation (sounds that persist after the source has gone quiet). There is an optimum amount of reflected sound in small listening rooms - not too live, and not too dead. Normally-furnished rooms (carpet, drapes, chairs and tables) tend to be close to optimum, but custom home theaters need to be treated.
This is one of the main reasons why a normal well-furnished room can sound so good. Combined with carpet/underlay, drapes, and seating the combination can work superbly with little tweaking."
It is a mistaken notion on these forums that unless you see a room of full of acoustic panels, the room does not sound good. Get well designed speakers with good off-axis performance and furnish your room as you would per above and you can have excellent sound. Now, if this is a dedicated room and you are only going to put a set of seats in there, then sure, you need to use acoustic products as "furnishings" but let's not subject every living/multi-use room to that based on the notion that if it is not there, it won't sound good. Formal research says it can and it does. The same research says that having acoustic material on places most everyone says to put here, is actually a bad idea.
Below transition frequency the tool of choice is (advanced) correction and proper number and placement of two or more subs. Once there, then you can resort to acoustic products as necessary. You want to reduce the magnitude of the problem first.
So no, there is no need to feel sorry for anyone having an untreated room