Axiom Home Page Forums General Discussion Advice from Axiom Owners What tone for sub calibration???

Ok, I keep trying to learn how to do all of this stuff, but there is so much, but i love it. Anyway, I have the a yamaha 5790 receiver and the avia disk. Do you use the pink noise to set the sub. Here is why I get confused, When I play a test tone at the 80 hz tone they are off, but when I use the pink noise they are the same??? What gives?? Also how do I create a chart of spl? Where do I get test tones at small increments to be able to adjust everything correctly?? With the tones on the disk they seem to be quick sweeps that I can't write down fast enough. Can anyone help me with this. I realize this has probably been covered before on the forum, but I couldn't find it. thank everyone..

JH, I also was a bit confused about what you meant by "off" and "same" in describing your results. In any case, for the setting of speaker and sub levels you can rely on the auto-calibration part of YPAO to do a good job, at least as accurate as would be done by a manual calibration using a test tone disc or the receiver test tones, aided by a SPL meter. If the resulting sub calibration, although probably accurate, isn't loud enough to satisfy(e.g.,"paid good money for that sub; want to hear it"), then it could be manually bumped up 3-4dB.

The main goal of pink noise is to calibrate all the speakers to the same dB level. Some receivers auto pink noise sets everything to 75dB's, some may be higher, the goal is to get everything the same. I think Avia's pink noise calibration is 85dB or something like that...

As John mentioned, I would run your receiver test with the mic in your primary listening seat at ear position. Many use a tripod and stand off to the side so YOUR not in the way of the speakers during the tests. After I've let my Denon run through the setup, I then take my SPL meter and put it in the same location as where I had the Mic, and verify the settings. Most receivers will let you manually cycle through each speaker one by one and adjust the levels up/down until everything is just right. It would be in the setup menus of the receiver.

Now when your talking about plotting a graph, that is to check your rooms freq response and look for peaks and nulls, this is different. Keep in mind that your graph from the primary position will be totally different than if you graph from another seat or location in the room. I can move my sub a few inches and that can really change the graph of the lower freq's. Position of your other speakers is just as important, and will effect your room response.

I would recommend that you just experiment with your left/right main positions and sub and let your ears be the judge. We can help you with basic positioning that should give you good results.

Graphing can be time consuming and really drive you nuts, ask me, I waste a lot of time figuring it all out. Many of the programs require a computer with full duplex sound cards to play/record at the same time. If your not computer savy I would forget about it.

The only free manual plotting program that I'm aware of is on the RealTraps website. They have files you can download and copy to a CD the play tones from 20hz to 300hz in 1hz increments. They offer a graph you can plot the results to see your low room response. It takes a long time and again the response you plot is only for that position.

Again, I would say just setup the room, use basic positioning and calibration techniques we discuss. Maybe add some room treatments and sit back and enjoy.

jhunt17

I suggest the Rives audio test cd 2. This cd offers tone tests at 20, 25, 31.5,40,50,63 and 80 Hz that are corrected to conpensate for the nonlinearity of the $40 Radio Shack SPL meter. What I did was run through these tone tests for the only 4 locations that I could put the sub in the room and make a graph for each one by hand. Then you can look at which location gives you the flattest response, simple as that. The cd also has tone tests corrected for the radio shack meter at 100, 125, 160, ..., 20000 Hz. You could stop at around 500 Hz to see how your mains and sub match up and tweak them get everything perfect. Or you can keep going up to 20000Hz to see how good or bad your room is. I found that the pink noise was about 5 or 10 dB off on the radio shack meter after comparing it to the results from the rives cd. So this cd is an absolute must buy.

- Nick