A while back we dug into
setting up a front projection system for that oh so sweet movie experience without the extra sticky floors. Today we're digging into the other side of the electromagnetic spectrum.
So you trekked over to your favorite electronics wonder barn and picked up a receiver, a bunch of speakers, and several tons of speaker wire. In an angry Hulk moment, you pulled the entertainment center away from the wall, hooked it all up, arranged your speakers, and then also your furniture. A few times, in fact. You popped in the most powerful sounding movie you could think of (don't tell us, T2?) and crashed on your couch in exhaustion. You've got surround sound.
In today's How-To we'll show you how to dial in your audio to help get the most out of your monster (or not so monster) sound system.
For today's How-To you'll need:
- Surround sound system
- SPL(Sound Pressure Level) Meter
- Test tones
Sorry guys, we're not going to get into deep discussions of speaker arrangements. Speaker placement depends on your speakers and the materials and acoustincs in room you're using. Your receiver should have included some specifications, but if you need some fresh guidance, check out the
Dolby layouts and
THX placement guides and decide what works for you.
The human ear is subjective. Everyone hears things just a little differently. Trying to set sound levels by ear is similar to trying to compare two weights by holding one in each hand. You can make a reasonable estimate, but you probably won't be all that accurate. (Think Indiana Jones and Raiders of the Lost Ark.[Update: Will needs more sleep])
To give us a consistent measurement, we need a mechanical ear. A quick trip to Radio Shack (Part# 33-4050) netted us this handy analog sound meter for about $50. It will give us a consistent frame of reference for measuring sound levels. Don't forget to grab the thoughtfully
not included battery. The analog is a bit cheaper than the digital version, and is generally held in higher regard than its digital counterpart -- gasp!
To tune up the system, we'll play a set of sounds through one speaker at a time. From the listening position, we'll measure the sound level from each individual speaker. In order to get a true calibration, it's better to play test tones from your DVD player rather than the built-in tones that your receiver produces.
If you picked up the Avia DVD from the front projection How-To, it contains audio test tones as well as speaker phase tests under the Advanced section of the disc.
The C setting tells the meter to measure the entire sound spectrum. Setting the response to SLOW will probably be easier to deal with. On fast, the needle might get a little crazy. Cue up some test tones and set the volume on your system to a comfortable level. Have a seat in your ideal move watching position. Now adjust the turn wheel on the meter so that the needle is somewhere in the middle of the gauge. (At 60, the 0 on the meter represents 60dB and so on.) If it makes it easier, you can tweak the volume a bit to center up the needle. From this point forward, don't touch the main system volume at all.
Unfortunately we have to do a little bit of math when it comes to measuring sound levels below 500Hz. When measuring the sound levels from a subwoofer, the meter will read on the low side. The guys over at the
AVSforum have used some high end tools to compare the results and suggest that with the Avia DVD, the meter will read low by about 2-3dB. The discussion was around the older meter, but it should be applicable.
To dial in the settings, you'll probably need the original remote. Ours allows quick access to the test tones, individual channel selection and level controls. Some receivers use software menus to access these controls. If you're not sure how to get there, google up an owners manual for your receiver.
As you cycle through each channel, you should be able to adjust each channel's volume. Some models may not let you adjust one channel. Make sure you start with that one as the control channel (what you compare everything else against).
Now it's time to bring all the pieces together. Sit down in your ideal listening location: couch, loveseat, whatever it is your speakers are aligned around.
- Put on your test tones either using a test CD/DVD like Avia or just the built in tones on your receiver.
- Reset the adjustment on each individual channel to 0.
- Set your volume to your listening level if you didn't already.
- Dial your meter in so that the needle is fairly centered.
- Using your center channel as your control volume, note the location of the needle on the SPL meter.
- Adjust each channels volume level so that the needle is in the same position as for the center channel (except the sub-woofer).
- Add 2 to 3dB from the needle's position and adjust the sub-woofer levels.
- Kick back Peter Murphy style.
That's it for our simple How-To on dialing in your surround sound system. Now it's time to start churning through the action section on Netflix and try this sucker out out. Don't be afraid to adjust your sound levels once you set them up. Even with all of today's sound standards, everything is mixed differently according to the sound tech and director's tastes. Enjoy!
posted Jul 19th 2006 12:19AM
T2 is the best movie ever! :-D
"Today we're digging into the another [sic] side of the electromagnetic spectrum."
What kind of sound are YOU listening to?!
:P
""Today we're digging into the another [sic] side of the electromagnetic spectrum."
What kind of sound are YOU listening to?!
:P"
hahaha i LOVE you for that man...how did i miss it!
You know, the guys at Engadget are living at the very edge of technology. They have radio receives attached directly to their acoustic nerves, eliminating the need for speakers, only a small antenna is needed. That is the future!
What should the orientation of the device be while doing this? I've done this before and there are variations in the levels depending on if the device is pointed straight up, level and towards the center, and everywhere in between.
"Trying to set sound levels by ear is similar to trying to compare two weights by holding one in each hand. You can make a reasonable estimate, but you probably won't be all that accurate. (Think Indiana Jones and the Temple of Doom.)"
That was Raiders.
Tsk, tsk.
THX-mastered DVDs (most of them anyway) should have tones and in/out of phase tests to go through this as well (which is where the T2 DVD comes in handy).
Curtis - I believe the "Video Essentials" disc (another great source for tones and setup screens) recommends holding the meter at ear level and pointed upwards at roughly a 45 degree angle.
I have to agree, I always hold my meter almost straight up when I test systems, that's really how it's designed (at least that's what I've read countless times).
It's nice to see this guide, so many people think you are supposed to "hear" your rear channels. YOU'RE NOT! You're supposed to "feel" them, and that's how the sound guys mix it. Making ALL your speakers the exact same level with test tones is the ONLY way to get this right. I hate it when I hear friends systems and all you focus on is the rear channel and they think that is so cool...
Nice guide...
If you really want to pump out some incredible sound...get a copy of Superman:The Movie Special Edition DVD. They remastered it, movie and soundtrack. It SOUNDS AMAZING. When the letters start to rumble and woosh by from the front speakers to the rear speakers along with that classic John Williams soundtrack blairing away, it just makes me want to wet my pants.
Rears are not meant to be "felt" - most rear sattelites are not capable of frequecy response low enough to "feel" (unlike a subwoofer). The mistake is that people think they should be hearing the rear surrounds all the time or very loudly. I think it is the "hey - I paid all this money for these things, why aren't they louder!!!" syndrome. Balancing the system as suggested in this article is the best path from getting the most out of your system - I know people who were amazed at the difference. It allows you to hear the movie as the director intended while at the same time providing your equipment the opportunity to perform at its best.
An easy way to find the best place to put a sub is to place it right by where you sit during a movie and walk around your room until you find a resonant spot (it will get suddenly louder).
* * * THIS ARTICLE MISSES A VERY IMPORTANT STEP IN DIALING IN A SS SYSTEM * * *
As a pretty die-hard audio guy (check my website), there's one thing that seems to always get missed when calibrating a surround sound system. Everyone always talks about the SPL side, but just as important is the time-delay side of things. Most good receivers permit you to change the relative levels of sound from each speaker, AND THEY ALSO permit you to dial in the time delay from each speaker to the "typical" listening position. If you're rear speakers are farther back than you're front speakers, without adjusting the timing, the sound will arrive at your ears at different points in time. The result is a subtle, but noticeable delay/echo if it is bad enough. So, don't forget about that -- most people just crank the rear speakers more under those conditions, but you might want to check the timing too if you are a true audiofile type.
" It's nice to see this guide, so many people think you are supposed to "hear" your rear channels. YOU'RE NOT! You're supposed to "feel" them, and that's how the sound guys mix it. "
That's not how the "sound guy's " mix it. I am one. And you don't "FEEL" your rear speakers, you obviously hear them. You only feel low frequencies; not mids and highs. Unless your running high SPL's into the pain spectrum of course. That's what the subwoofer is for. It's also why there is bass management. Generally, your rear channels are put on the sides or off axis anyway, so of course you are going to hear them. It all depends on content and how it was mixed. Basically " THE BUDGET". That's why there are good movies and bad movies. Calibrating channel levels is always a good idea. But room acoustics and the dynamics of the content play a big part as well. As well as the ego of the sound director.
This article is a little off. First off it is actually better to use the test tones from your reciever because this will ensure that all of your inputs have the same reference level. If you get a better white/pink noise off a test dvd than your reciever perhaps something is wrong elsewhere. Furthermore do you see a volume knob on your dvd player? Of course not.
The whole point of this type of calibration is to 1) Set the reference level 2) Ensure all speakers produce that reference level from the listeners position.
If you go by these(from the article) instructions you quite possibly will end up with a dramatic decrease in dynamic range,since your starting point is flawed.
Most recievers will automatically set the volume to zero when playing test tones. This is exactly what you should be doing. You want to set this level to a reference standard. Most recievers use the standard THX level and play their test tone at -30dbfs when at 0. This means that you should calibrate your levels so that each channel plays at 75db. This ensures that when at 0dbfs your maximum SPL will be 105db.
Once you have set your reference level, then you can as they say "Set your volume to your listening level".
Also LFE levels are usually 10db hotter so using a dvd test tone may skew your results. But of course sub volume is a matter of taste.
As said above you should also calibrate your delay timings too...