Du tres basic!!
THE PLACE TO START in any room is a simple test of where your at. How good, or how bad IS the room. I always focus on frequency balance first. Premiere chose a faire
Walk around in your room and clap your hand once from different locations. Listen to the sound - in particular the decay. The hand clap should sound dry and tight. You should hear the sound come from everywhere at the same time. The sound should stop almost immediately after each clap. If you hear the sound come from your hands and nothing from the room, the room is too dead. If you hear the sound come from the room as being louder then the sound from your hands the room is too live. Ceci est le RT60 en tout petit!
50 milliseconds is considered a good decay. In a hard room it's not uncommon for the decay to last over 1 second. When this happens, there is a ringing associated with each clap. You can repeat this test over as you add treatment to your room.
Assuming your room needs some treatment (most do) The most obvious place to start is with the bass. When bass is properly treated two things happen. A) it tightens up and becomes articulate and
reduces the difference between the hole in the middle of the room with no bass and the area around the perimeter of the room where there is usually too much bass. The most common surprise once someone has corrected the bass response is how much bass effects the midrange and overall focus of the sound stage.
The common 60 to 80 cycle region that is typically way too loud in most moderate size rooms is called "room boom". Room boom is bad. Bass traps are the most common way to correct low frequency issues. The problem is, many bass traps only work across a narrow band of frequencies, most of them too high to correct the whole problem. Bass traps to be effective always end up being large. It's easy when your building a room to incorporate bass traps into the structure in a way that can not be seen. In finished rooms you have limited options. The best product I've seen so far that works for everyone is the CWAL unit by Acoustic Control Co. It is a large corner unit that absorbs across a wide band of frequencies and is always noticeable. Tube traps are less effective but easier to purchase since you don't have to build them yourself.
A separate paper would be required to deal with all the different types of traps and how to use them best so I won't cover it here. If you're not a handyman, the best thing is to buy what you can find, and settle for something is better than nothing.Ici, vous pouvez aussi mettre du feutre sur le baffle de le hp. C'est pas exactement pareil mais si WAF est important...
The next thing do is deal with midrange and high frequencies. Absorbing these is far easier than absorbing bass frequencies. A sponge on the wall can absorb a wavelength equal to around 4 times it's thickness. That means a 2 inch thick sponge can easily handle high frequencies, but it would take a sponge about 15 feet thick to handle low bass notes. That's why bass traps were invented, an attempt to reduce the size needed to get the job done through more efficient means of absorption. Ma maladie non acceptable!
The ringing associated with the hand clap starts at around 2 kHz and can easily be treated with thick rugs, 2 inch foam, or heavy draperies. Carpet, and the type of padding under it will have more effect on the decay of your room than anything you will put on the walls. Unless of course you plan to create layered absorbers for your walls, by placing an air space or padding behind thick materials. Un mini comprehension sur le Comb Filtering
Your room should be a combination of reflective and absorptive surfaces. For example, a soft floor (carpet with padding) and a hard ceiling. An ideal to shoot for is NO TWO PARALLEL SURFACES should be the same. If an area of one wall is treated with absorption, the opposing surface should be reflective. It is possible to make two whole walls soft, and leave two walls hard and get a fair result. A better result comes from mixing it up a bit more than that.
Diffusers can be considered to replace the reflective surfaces of your room and should be especially if your room is small. The smaller your room the more important diffusers become.
If you diffuse the sound that reflects off the front wall you will have depth in your sound stage that appears to go right through the wall. Once you have diffusers placed on your front wall, some carefully placed diffusers on each side wall will enhance the performance of those already placed on the front wall. In addition they will allow your sound stage width to expand in the same manor as the depth did when you treated the front wall.
Adding diffusers to the rear wall will enhance the performance of any other diffusers you have in your room. An ideal that is not too realistic would be to replace every flat surface in the room with some sort of diffusion.
If you listen to a system without diffusion vs. one with diffusion you will notice something else begins to happen that is closely related to frequency balance. In the untreated room the louder you play the stereo, the worse it typically sounds. This is the point where the room takes over. In a treated (diffused) room this point where the room overcomes the system is pushed to a point beyond your worries. In fact it almost seems the louder you play it, the better and bigger it sounds.
In conclusion, you need to create absorptive surfaces with either foam panels or wall rugs in places around your room so that you eliminate as many parallel surfaces of the same hardness as possible. You need to install some sort of bass traps in the corners to absorb the room boom. You need to install diffusers in the correct locations to enhance the focus and size of your sound stage. Doing so will add consistency to the sound of your system. You will have less moments where it sounds bad, less distractions to keep you from the music. Only under these conditions is your system capable of fully showing you the differences between one type of cable or another.
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Ce message a été modifié par Anglofun - 08 September 2008 à 17:13 .