R-DES Using the System: Step by Step
Let's just take this slow so that you a) know what you are getting yourself into and b) know what to do once you get this box. These directions assume that you are using an SPL meter (like the Radio Shack version).
Setting up the R-DES and utilizing the Onix Graph Paper program:
- Install software following the supplied directions.
- Connect Onix R-DES box between the receiver and the sub (I used the right in and out). You'll need an extra subwoofer cable - preferably a short one. For now, hook it up near the sub where you can get to it. Later, you can move it to a more discrete place if you like. Press the right button until the Bypass light is lit
- Disconnect your front speakers (simply unplug them from the back of the receiver or turn them off from the speaker selection menu on your receiver). See our Editor's Note below on why we think you may want to actually leave your main speakers on.
- Disable any matrixing DSP on your receiver (set to Stereo with sub).
- Turn the volume on your receiver DOWN! The first track is test tones and they are recorded pretty loud. You don't want to hurt your ears or, God forbid, your speakers by blasting pink noise.
- Set up your SPL meter at your prime listening position - preferably on a tripod.
- Open the Onix Graph Paper program.
- Hit the "New" button.
- Select "Long Sweep."
- Insert the CD (yes the one with the installation program) into your CD/DVD player in your system.
- Hit play.
- Increase the volume on your receiver until the SPL meter reads between 70-75Hz (make sure you set it to "C" weighting). Record that number in the Noise SPL box.
- Hit pause.
- Under "Correction" select "RS Meter" if you are using the Radio Shack SPL meter. If not, leave it on "None." If you select RS Meter, you'll notice a dotted line within your graph. This dotted line shows your actual measurement. The graph is different because the RS Meter is known to be inaccurate at those frequencies. The graph is modified accordingly.
- Turn the directions for installing the software over. Notice the play list. This lists the track numbers and the corresponding frequency being played. Each track is a different frequency. They are listed in order on the left side of the Graph Paper program. If you take a reading and enter them in order, you may never need this. Chances are, though, you'll lose your place at least once. Every once in a while be sure to check where you are just in case.
- Turn your SPL meter down to its lowest setting (60dB for the Radio Shack version) and press play.
- Don't be surprised when you don't hear anything until about Track 6 (20Hz). Those frequencies are inaudible (though you may hear something in your house vibrate). Keep an eye on your SPL meter to see if they are registering.
- Each test tone will play for ~10 seconds. You will quickly become adept at adjusting your meter, taking a reading, and inserting it in the program in that time. Still, have your remote handy.
- When you are done HIT SAVE . If you don't and close it, you'll lose your graph forever (it will not ask if you want to save). If you wish to save an image of your graph to share with others, drag and drop it on your desktop.
Ok, now you've got this pretty graph - what do you do with it?
Editor's Note: Tip on SPL meter usage and the integration of your main speakers
There are few things more important in this process than taking an accurate measurement. It is an absolute necessity to get your body away from the meter when taking a reading. Don't believe me? Set the meter up on a tripod. Play a test tone at a specific frequency. As the tone is playing move toward the meter and reach your hand out to grab it. Watch the pretty needle jump around. The most common mistake when using the RS Meter is to hold it in your hand. You'll think the thing is broken as the readings will change each time you take it.
Also, though the R-DES directions instruct you to turn off your main speakers, we actually recommend keeping them on as most users do not have "brick-wall" crossover points. The bass extension of your main speakers will almost certainly affect overall low frequency and room response.
Using the Onix R-DES program.
When you open the program, you'll notice one preset and four possible curves listed under it listed as "Default" down the left side of the screen (you can right click on these to change their titles). At the bottom, there is a button labeled "New" that will allow you to create a whole new preset with four more curves underneath it (up to five of these). For now, ignore that button. At the top, there is a big arrow pointing up that is grayed out and can't be clicked (yet). There are six columns, five labeled " EQ" and one labeled "Crossover". In each of the EQ columns there are three dials. The top one is for decibel (or degree of change). Move the dial to the right (clockwise) and you'll boost the frequency selected, move it to the left and you'll decrease it. In this process, we will only be decreasing. The middle dial is for the frequency. When you find a frequency you want to adjust, you simply move the dial until the readout indicates the correct frequency. The last dial adjusts the Q or the width of the peak. This will make more sense once we get into it. Lets take a hypothetical situation and go with that - Lets say you have sloping rise at 30Hz and a dramatic spike at 70Hz (see the graphic). You want to reduce these two problem areas by lowering these frequencies.
- In your first curve, set the first column frequency (the second dial in the first column) to 30Hz.
- The apex of the bump is about 5 decibels (look at the number on the left of the graph) higher than the rest of the graph. Set your dB dial (the top one) to -5 or so.
- You'll notice that the shape of that curve is going in the opposite direction as the one in the graph above. That is good -舑 it is what you want. It is also more dramatic than the one on the graph. You want to as closely approximate that as possible.
- Adjust the Q (bottom dial) down or counter clockwise. This will make that slope a bit more gentle. Keep working with it until it approximates the mirror image of the original graph. You may have to use more than one of the EQ columns working together to get the proper results (for example one set at 28Hz and the other set at 32Hz rather than one set at 30Hz).
- Do the same with the 70Hz bump but instead of moving the Q down (counterclockwise) move it up (clockwise). This will increase the angle so that it is sharp.
- Now EXIT THE PROGRAM . It will ask you if you want to save. Hit "yes." Now reopen the program. Get used to doing this. Much better than losing your work.
Setting the Crossover
Honestly, with today's receivers, you may have little use for this function. You have two buttons and two dials. The buttons select how steep a crossover you want to set (the left is a gentle roll-off and the right is more steep). The first dial sets the frequency you want the crossover to be set. This is what you need to do:
- Disable the crossover on your sub by turning it as high as it will go or selecting "Bypass" or some similar setting (you've probably already done this).
- On your receiver, disable your crossover. If you can't disable your crossover (I couldn't on my Denon 3805 ) then stop here and use your receiver's crossover. You can disable the crossover on the R-DES by turning it all the way up to 120Hz (your receiver crossover should be set lower than that).
- Select the frequency and slope you want on the crossover.
- You're done.
Yeah but what about that other dial? The decibels dial? What's that all about? The use for that is if you had a need for more bass in particular applications. Say you EQed everything fairly flat and music sounded great. But now your movies don't have that punch you are used to. Well, redo your entire EQ set up in a different curve and move the decibel dial up a few points under the crossover. This increases the volume of the sub overall. Personally, I'm not using it.
So you're done right? Not quite. Now you need to get the new settings to your R-DES. This is probably the easiest part of the process:
- Open the Onix R-DES program.
- Connect the R-DES to your computer via the supplied USB cable.
- The arrow at the top of the screen with light up, click on it.
- Watch the pretty lights on the R-DES for the next second or so.
- You're done!
Or not. If you are infallible and/or an expert in using a parametric EQ, you can be sure your EQ attempt was successful and go on to enjoy the sonic bliss you've created. If you are somewhat less than an expert, you want to go back and take new measurements and perhaps readjust. Then take more measurements and readjust. You get the idea.
Now for some helpful hints:
- Whichever curve you were viewing on the screen is the one that the R-DES will default to when you upload the EQ settings. If you were viewing Curve 1 and you want the unit to be set on Curve 4, you'll need to change that manually.
- Save your work. Constantly save. When you are absolutely, positively sure you've saved, save again.
- Do yourself a favor; line up the EQ columns from low to high frequency, left to right. If you start skipping around, you're going to get confused and mess up something you had perfect.
- You don't have to keep taking the same measurements over and over once you've got something dialed in. If your problem area is between 20 and 50Hz, and you haven't changed anything, just take those measurements. This significantly reduces your workload. You can also use the short sweep version if that is more appropriate.
- If you have another program that takes measurements, you can use the blank form to graph your response. It will only graph the frequencies displayed (up to 120Hz). The graph will not expand if you include higher data points.
- Your EQing will change the overall level of your sub in relation to the rest of your speakers. You need to check that after you finish this process with your receivers test tones. You'll probably find you can turn your sub up.
- Avoid EQing up (boosting a signal) like the plague.
- You have multiple settings in the R-DES system - use them. While you may get a great response for your primary listening position, it may make sense to take several measurements from different seating areas. When you have guests over you may opt for a setting that gives you more overall good bass response, though the "golden seat" may not fare as well.
Editor's Note: But Why ..........?
Most dips in your frequency response are created by "nulls" or "room nodes" or "room effects." They are all the same thing. Think of it this way - sounds are waves. They bounce off of walls, floors, and ceilings. When they bounce they hit themselves again. If the reflection is at the high point of the wave and it hits another high point, it makes the wave stronger (louder). If it is at the low-point and it hits a highpoint, it cancels itself out. If you cut the artificially increased signal, it will be boosted less. If you boost the cancellation frequency, it will still bounce and still cancel itself out. The only way to fix that is through room treatments. They absorb the sound so it doesn't bounce. No bounce, no cancellation. No cancellation, no null. A simplistic explanation but this isn't meant to be a course in acoustics. Properly placed multiple subs can also help smooth bass response.