Axiom Home Page Forums General Discussion Home Theater HT Set Up Help

Are both subs calibrated properly in relation to the other speakers using a SPL meter and test tones?

No but could use some help with this, I just go the SPL meter this week and I have the test tones DVD. Not sure how to do this correctly.

Rdelpozo, if each sub isn't calibrated,then meaningful comparisons are almost impossible. Say you set the volume knob on each sub at 50%, but the STF-2 is louder at that setting than the EP175. Almost any sub will sound boomy or abnormal if turned up too loud.

Calibration is very easy. The easiest way is using your receiver's pink noise test tones. You just switch from speaker to speaker while playing pink noise, and make sure the meter reads about the same from each speaker, including the subwoofer. Typical levels to calibrate to are 70, 75 or 80db. For 70db, set the meter on "C" weighting, slow response, 70db scale. When the dial says 0db, you're reading 70db sound. For 75db, use the 70db scale and the needle will reach +5db (75 = 70+5).

Adjust your master volume to about the right level to hit 70 or 75db. The receiver or DVD test tones will usually switch from speaker to speaker automatically. When on the subwoofer, if it reads too low, turn up the subwoofer volume knob. If too high, turn it down.

That said, some people like a little more bass. It's perfectly OK for your sub to be (say) 3db louder than your other speakers, if that's your taste. Just make sure you set both subs to the same +3db point.

Don't point the meter at each speaker. Hold it roughly straight up.

Using tones from the DVD is better because it incorporates the entire playback chain. However most test DVDs have many different test tones for varying purposes. For example, low frequency sweeps to check for room rattles, etc. For your immediate purposes you don't need those.

What you want is a basic subwoofer level calibration so that both EP175 and STF-2 are set properly with respect to your other speakers. Pink noise is the best for that. It only takes a minute once you get the hang of it.

Calibrate the EP175, do some basic listening tests. Then hook up and calibrate the STF-2 and repeat the listening tests. My guess is they'll sound much more similar after doing the calibration.

I'm interested in how much difference you can hear between them after both are calibrated.

Thanks alot Joe, I appreciate the help in getting this done right. I realized once I got all my gear set up that it would take some know how to get it calibrated correctly. I did not realize that my surrounds were not even working until I put the test tones DVD.

Speaking of surrounds do I set this up louder the rest or same, I have the QS4's and when watching movies not really sure how much sound you are suppose to hear from then.

I will do all the steps you have recommended as soon as I get home from work and let you know, I do not know what pink noise is, hopefully the DVD I got from Partsexpress "Ultimate DVD Silver Special Edition" has them.

When calibrating with test tones and a meter you set your surrounds to the same loudness as your other speakers.

During a movie or music, several things affect how much sound comes from the surrounds. If the material is discrete 5.1 (Digital Dolby 5.1, DTS 5.1, multichannel SACD or DVD-A music) the amount of surround is dictated purely by the mixing engineer. It's an artistic and aesthetic choice when the material was mixed. You can't really change it much except by overriding your surround volume and going to non-calibrated levels.

If the material is stereo, you usually won't hear any surround unless your receiver has a mode for reconstructing surround from stereo. Examples are Dolby PLII and Harmon Kardon and Lexicon's Logic 7. In that case amount of surround depends on the reconstruction technology and characteristics of the stereo source. Some stereo material will produce good surround with PLII/L7, and others don't.

Pink noise is what the receiver and DVD player test tones often use. It's usually on your calibration DVD as well, along with a lot of other stuff. Read the literature or on-line documentation that comes with that.

Don't worry, it's not hard at all, once you get the hang of it. After a while you can do it without even thinking about it.

Think of it as an opportunity to 'tweak' your setup. I'm going to take a chance and make the assumption that if you are posting/reading this forum that you enjoy getting as much out of your system as you can.
Personally, I was almost salivating at the chance to dial in/tweak/play around with the settings for my HT to get the best sound I could. Being able to do this was ½ the reason I am getting into this hobby. But then I'm the type of guy who is happy with 5 computers and 7 OSs running in his home. Gee, and I wonder why I’m still single?

Joema - Thanks for all your help. I followed your steps and was finally able to calibrate my system and the 2 subs the same. Both subs sound great and I really can not tell which one sounds better than the other. One is just as good as the other in my opinion once calibrated the same.