HSU STF2 sub concerns - please advise

[edwelly]

Hello all - I bought a VT-12 and STF2 combo for my mom. Great sounding stuff and easy install. However, I did have a question about the STF2, please. We watched War of the Worlds - the scene where the machine comes up thru the ground. I realize this scene has a lot of bass but I was concerned with how much the the STF2 woofer moved. I thought it was going to pop as it was moving so much. The system was calibrated using the Avia disc and an SPL meter so I don't feel like it was due to that. I have the sub about 2-4 dbs higher which should be fine. I am basing this woofer movement and sound on my own SVS PB-10 sub. My sub puts out more bass and doesn't move anywhere near what the STF2 did. I realize that we are talking about 2 different subs and 2 different rooms - I am just concerned with the movement. The STF2 is sitting on a hard wood floor - I know I need to put some carpet under it but the whole house is hard wood.

Any suggestions or am I worrying about much of nothing???

Thanks!!!

 

[AVRat]

Do you mean the whole box was dancing? Not to worry, it just needs to be stabilized somehow.

 

[Wid]

If the Stf 2 was not bottoming out (the familiar clapping sound) I wouldn't be too concerned with the movement of the driver. If it handled that movie rest assured it should do fine with most other movies.

 

[edwelly]

box was not moving BUT the woofer had to be reaching close to maximum excursion - same thing on the POD race in Star Wars...
just concerned is all...

 

[Sheep]

That scene in WOTW has bass down to 10 Hz. A woofer tuned to 25Hz will move, no matter what.

You should hav seen my athena on that one., had to turn the volume down for that scene.

Remember, movies tend to have more bass then Music. So, your calibration might need to be adjusted for movies.

SheepStar

 

[edwelly]

Sheep - same with the pod race?

 

[Sheep]

Sheep - same with the pod race?

I don't know. Havent see ntaht scene for a bit. Although it does have deep bass, I don't have any waterfall charts for it.

SheepStar

 

[Wid]

I have the sub about 2-4 dbs higher which should be fine.

If you are reading 87 to 89 DB on your RS meter calibrating your sub then you actually have the sub set to 90 to 92 which is a bit to much. When using the Avia disc there should be a correction of -3 DB on the meter.

Here is the the article where I read this information.

 

[edwelly]

Wid
Hmmm - how I set it up: I used C scale and set everything to 70 db - then on the sub, I would use the sub > Left, sub > center, sub > right and had the sub moving about 2-4 db more than that. That seems like it would make everything the same level - is that not correct?

 

[Wid]

edwelly,

Try and run a test tone with the sub only, if you are using 70db as your reference point and you want the sub to run around +3 db hotter then the rest of the speakers you should set the sub to read 70 db also. The RS meter is around -3 db when calibrating a sub. Here is another good read from SVS that tells one that the "Radio Shack sound meter is relatively insensitive at very low frequencies".

 

[Tex-amp]

What made you turn a down firing sub on side and watch the driver? If the Hsu driver a was in a cabinet as large as the PB10 it wouldn't be moving as far either.