Subwoofer's. How much shake?

Garrett Lundy · 02-20-2004, 11:57 AM

I recently received my SVS PCi20-39, and retired my 200-watt RCA subwoofer to being an end-table. I calibrated my levels and started watching movies and listening to music.

I set my speaker levels to 65db using the Sound & Vision home theater tune up DVD and leave the receiver on the same setting when watching a movie. Using my Radio Shack SPL-meter I dialed the subwoofer to 63db's, which I understand to be flat because of the SPL bass-insensitivity.

On my apartment's archaic wood floors the SVS shakes the entire dwelling (Not just the room) during a heavy bass scene (the prologue of LOTR:TFOTR:EE for example). But I only get a moderate "thump" of tactile vibration from a CD with taiko drums or other percussion gear.

Anyway, my question is such: How much should my subwoofer shake my apartment? Is the LFE supposed to be more heard than felt, or is it more felt than heard? I'm finding the SVS super-rumble to get too distracting from my entertainment! (Not nearly as bad as the lesser subwoofers horrible distortion and bottoming-out).

I've heard of people placing their subwoofers on stone or concrete raiser to diminish the bass effect, or even building a "floating" stage to help contain the shakes. Is this a sound idea or just more "green cable" audio-voodoo.

The local movie-plex doesn't have subwoofers and the audio-dealer only carries Paradigm PDR-10's. I don't know how much bass is correct because I have nothing to compare my SVS to! Help!

Any help on this? Is violent shakling normal and I need to get used to it in action movies, or am I suffering from some sort of wood-floor acoustic mess?

PS: Sorry I tend to ramble on alot. :b

ChadLB · 02-20-2004, 03:05 PM

IF I may ask why are you using 65db with the S&V disk. I emailed them and it is 85db? Just curious.

Garrett Lundy · 02-20-2004, 04:04 PM

Because at 85db the test tones are really, really loud. So I use the tones and set them at 65db, thats all.

douglas-b · 02-20-2004, 04:38 PM

I noticed when I used the Sound and Vision disk to calibrate my system...the test tones seemed to be at different levels. I calibrated my speakers to 85db. When my receiver is at "00" I'm at 85db (reference level) then I went to the subwoofer level and I had to have my receiver at "-7" to keep the test tone at 85db. Now that I've typed that I understand why...the Left channel speaker is set to +7 on my receiver.

Philip>L · 02-20-2004, 05:37 PM

If I'm not mistaken, you're supposed to calibrate your system to a reference level. Then, if you prefer to listen at a different level you can. The tones were designed to be used for a calibration at 85db.

Keep in mind that a good home theater should FAR outperform a cinema in sound quality and feel. And a properly calibrated subwoofer should not stand out when playing music.

Sounds like your system is pretty close to being properly calibrated. However, if you don't like the sub's power, turn it down a bit...

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John Garcia · 02-20-2004, 06:37 PM

In all likelihood, what you are hearing is a difference in frequency range. Those drums are low, but are not in the same mid to 20s that you will find on some movie soundtracks. Another possibility is that you have room modes that either accentuate lower frequencies, and/or decentuate something in the 40-60Hz range.

I would have to agree with calibrating at 85dB, rather than 65. It's only loud during the calibration.

Dustin B · 02-20-2004, 06:58 PM

I'd disagree. Calibrating at 65 is fine. All you are doing is calibrating your system to 20dB below reference. I typically watch at 10-15 below reference.

There's little difference between calibrating at 85dB and then using one tone to quickly find out what 20dB below reference is and calibrating at 65dB and then turning one tone up to quickly find out what reference is. Either way you've level matched your speakers and that's all that is really important.

Garrett Lundy · 02-20-2004, 07:41 PM

So nobody is suggesting I buy a heavy-ass rock to set my subwoofer on? Whew..... I didn't want to lug anything into my second story walk-up.

Michael__M · 02-21-2004, 09:08 AM

Movie soundtracks typically have much lower frequency bass material mixed in you will find in music. Sounds effects from the movies are meant to be felt, not just heard as in music. The difference you hear is supposed to be there. I usually read posts from people not getting enough shake from their subs. As stated above, you probably have some room nodes in the mix causing some drones down low.