Calibrating new STF-2, am I doing something wrong?

[dkwong]

I just purchased and received an HSU STF-2 yesterday, and first impressions are that it's _loud_! Keep in mind that I didn't have a sub prior to this, so I have nothing to compare it to.

I do have a question regarding calibration though. I bought the Radio Shack analog SPL meter and tried to set up the sub with it and my receiver's pink noise test tones. So I set the volume of the receiver such that the output of the main speakers is at 75 dB and then switched to the sub output only to configure its volume level. However, even before I get close to 75 dB, the sub's output is overpowering. At 75 dB, it's so loud that it's unlistenable. I eventually had to settle for about 65 dB for the sub and 75 dB for all my other speakers. Even at this level, the sub is incredibly loud during movies (I tested with the opening scene of FOTR, the launch scene of Apollo 13, and the New York scene of Armageddon). My question is am I doing something wrong with the calibration? If not, how can other people enjoy any movies with the sub output set so high?

[tdekany]

Did you try to turn the volume down on the sub? Where do you have it set at?

[dkwong]

Well, I am using the volume knob on the sub, but that's not the issue. The issue is that I was under the belief that the sub should be set to the same volume level as my other speakers by using the SPL meter. However, if the sub is set to that level, it is unlistenable because it is too loud.

[Lwang]

What source are you using to calibrate? Some require your sub to be at 75 or 85dB. Also, you have to use band limited pink noise, 20-80hz for the sub and 80-20k for the other speakers. RS SPL meter has to be set to C-weighting and slow response.

If you are complaining about DVD's LFE being too loud. That is the way it is.

[dkwong]

I'm using the receiver's speaker level calibration noise to calibrate. I will try using the Avia disc and see if that produces any different results.

[Lwang]

with Avia disc, you would have to calibrate the sub to 85dB.

[Dudley]

Are you using C weighting? That can make a big difference.

[DavidD]

I admit I don't know what is going on here. 75db should be 75db. Have you tried Avia yet?

[dkwong]

Dudley got it on the nose. I was using A weighting, which does make a big difference. Using C weighting brought everything back in line. Thanks everyone!

[tdekany]

Originally posted by dkwong
Dudley got it on the nose. I was using A weighting, which does make a big difference. Using C weighting brought everything back in line. Thanks everyone!

Just out of curiosity, what is the set up like now and what was it before?

[Dudley]

Glad it is working correctly now.

[Lwang]

Didn't I mention it to you early on about C-weighting?

[dkwong]

Lwang, you're right. I didn't get a chance to try out the SPL meter again until last Thursday, and by that time I had forgotten about your post. Sorry, and thanks for the info.

tdekany, the sub sounds much more natural now. Prior to this, I couldn't rely on the SPL meter's readings so I set up the sub using my ears. That produced a very boomy and rattly (if that's a word) sound. With the SPL meter set correctly, I found that I had set up the sub too loud. Turning it down to the right level corrected the boominess and everything sounds great together.

[mjzraz]

dkwong,

When you say you turned it down to the right level, are you talking about the volume knob on the subwoofer amp?

[DavidD]

I don't know what dkwong did, but when calibrating it could be either on the sub or on the receiver or preamp. Calibrating can involve tweaking both.

[dkwong]

I used the volume knob on the subwoofer amp and left the receiver at 0db.

[IJR]

Is there any advantage/disadvantage to doing it either way?

i.e.
1. Leaving the Receiver at 0db and adjusting level via the subwoofer's volume knob
or
2. Leaving the subwoofer knob at a specified point (let's say 1/4 way up from 0) and adjusting level via the receiver's subwoofer level control?

I would prefer to do it the #2 way purely for convenience sake (sub is in corner, volume control is in back, receiver has remote control for adjusting levels), but if it's better doing it the other way, I am open to it.

[Dudley]

I don't think it matters too much either way. Some prefer to have the value at the reciever to be on the plus side so that the auto on feature gets a nice strong signal. I have my reciever set at about +6. My STF-2 is at about 40% (or about 10:30)