SVS 20-39 PCI Bottoms @ -12? (1 Viewer)

[Larry Marq]

Well it was during the opening of ATOC...I originally thought it wasn't...Am I expecting too much from this sub? Is a PC-Plus less likely to bottom at this level (preferrably even louder, like -5)I haven't tried other movies yet. Will the LFE level setting help under surround parameters on a Denon 3803? I like it loud and am willing to upgrade to the plus (I know, I know...) But I don't want to spend 225 more for only a LITTLE louder..Thanks, Larry

 

[Ned]

"-12" doesn't mean much. Set your meter to C, fast, and see how loud it's actually playing when it bottoms.

My single 20-39CSi is good for about 110-113db of output at my seat in my 12x10 sealed room.

 

[Dan Joy]

Larry,

There are many things to consider. -12 on my receiver is.... well thats pretty F-ing loud,, louder that I have ever came on my DA5ES. I have a SVS25-31PCi and have never bottomed it out. Reference for me with Avia and Rat Shack meter is -26. You better email SVS before you do something you regret. Calibrate before you play loud or take your consequences!

 

[Larry Marq]

104 db about when I hear it clack...17x15 semi open room...
That is calibrated to internal tones, all speaks set to 75db except sub..So I'm set to 12db BELOW this 75db ref
Thanks, Larry

 

[Dan Joy]

What are your other speakers, whats the gain on your sub at , and whats your subwoofer level on your Denon at with ranges?

 

[Tom Vodhanel]

Hi Larry,

Where is the subwoofer located, in/near a good corner of the room? Also, what is the distance between the subwoofer and the key listening positions? Just curious---but what did you end up with on the speaker and subwoofer settings internally in the Denon (to get them all to 75dBs)?

Are the listening positions near large openings into the room? Is the 20-39PCi OK with DVDs like IRON GIANT,The PROFESSIONAL, MATRIX, BLADE-1 ?

Tom V.
SVS

 

[Larry Marq]

Hi Tom,

The sub is about 12' from me at right front corner..there is a hall opening close to the corner on the right wall...Speakers set at
LF -3
C -3
RF -3

RS -1.5

LS -1.5
using internal tones on 3803. With AVIA it was fronts at 0db (forgot the surround setting)

NOt sure about the other movies yet...just set it up

Thanks Tom

Larry

 

[Edward J M]

all speaks set to 75db except sub

Larry:

Waiting for the other shoe to drop here......

I'm assuming you are using Master Volume 00 for speaker calibration. What is the internal sub level setting on the Denon? What is the SPL meter reading (on C-Weighted Slow) at the couch for the Denon's sub test tone when the Master Volume is set to 00?

Also, when you say 104 dB, what is the setting on the meter (C-Weighted Fast or Slow), and where is the meter located?

Finally, have you taken readings on the meter for this passage at more than one location?

I'm thinking three things, possibly:
1) The sub might be calibrated overly hot.
2) The sub might be placed too near a permanent opening.
3) You might be sitting in a room null.

Experimentation with placement might alter your calibration and playback results drastically. Can you try the sub in another location?

Regards,

Ed

 

[Larry Marq]

Finally, have you taken readings on the meter for this passage at more than one location?

Nope.


After Talking to Tom at SVS, it seemed I might be pushing it too hard, considering the attached open rooms. U-571 had no probs and seems much louder overall than ATOC for any given setting on the 3803.

It seems the RS SPL meter show a different method of holding the meter than does the AVIA disc. AVIA states it should be held perpindicular to the source. RS says towards the source if I understand it correctly. SVS says in there manual set speaks at 75 or 85db for "full range" speakers. Does that imply a different reading for other than full range? I think I'll ask Tom that one...

Thanks for the help, Larry

 

[Chris_O]

Larry,

I would try moving your sub. My room sounds very similar to yours. When I first got my sub I place it in my right front corner and was less than impressed with the bass. My right wall has a large opening about 3 ft. from the corner where my sub was sitting. I moved my sub to my left front corner which doesn't have an opening on my left wall. The difference is night and day. I calibrated my sub using AVIA to 87 DB and I have never bottomed out. My sub is also about 12 ft. from my seat. My room is about 14' by 18' and I have a 20-39 PCI.

 

[Willem Vos]

Larry, you still haven't said at what position the gain on your sub was set at.

Tried 0db and -6. Same output...

Am I missing something here? Shouldn't there definitely be a difference in output when you increase the sub level? (Assuming the Gain on the sub and the volume level on the denon stays at 00)

 

[Edward J M]

Larry,

Definitely experiment with room placement to the extent that is possible. I think you could be looking at a combination of loss from a too-close permanent opening, and also possibly a room null.

Do you have the capability to burn a CD with test tones and run a frequency response sweep in the room? It will show if you have a major drop-out anywhere in the curve that could be contributing to a weak bass response. Many users find plotting the FR curve to be a very useful tool in evaluating their sub performance. If you are interested in this, let me know. I can even set you up with a custom Excel spreadsheet that automatically includes the RS correction factors - all you have to do is input the raw data and it will spit out your curve.

If you are not interested in doing an FR sweep, a time honored method that still works pretty well is to place the sub at the listening position and crawl around the room, listening for the best and/or strongest bass response. When you find that location, try the sub at that point and see how you like it.

Regarding the 75/85 dB question - that calibration volume applies to all high quality surround speakers regardless of physical size or bass capability. The real issue here is if you are using tiny satellite speaks, then your high pass filter point needs to be set at 100 or 120 Hz in order to avoid a depression in the FR. You cannot run tiny sats high passed at 80 Hz - it just won't sound right and you might damage them at higher volumes. If you are running decent sized speaks all around (say with an F3 of 55 Hz or lower), then an 80 Hz high pass will work great.

Willem:

I think Larry may have been experimenting with different sub settings to see if his 3803 is experiencing a possible bass management problem discussed over in the AVR and amp section of HTF. I think it was implied that he recalibrated again to 75-78 dB after he lowered the sub setting from 0 to -6.

Regards,

Ed

 

[Willem Vos]

I think Larry may have been experimenting with different sub settings to see if his 3803 is experiencing a possible bass management problem discussed over in the AVR and amp section of HTF. I think it was implied that he recalibrated again to 75-78 dB after he lowered the sub setting from 0 to -6.

Yeah, I suspected that, because otherwise it doesn't make any sense...
I'm still curious to know the position of the gain on the sub itself. If it was turned completely to the right, with the sub level on the receiver at 0 or so (if that was needed to have it calibrated at 78dB with the volume at 00), a "violent" movie scene at -12 denonvolume would probably be too much for the sub.

Probably.

 

[Edward J M]

I'm still curious to know the position of the gain on the sub itself. If it was turned completely to the right, with the sub level on the receiver at 0 or so (if that was needed to have it calibrated at 78dB with the volume at 00)

I agree, and this speaks to a possible null or a huge loss from a permanent opening. If he needs more than about 1/3 gain on the sub amp for 78 dB on the meter, with the 3803 sub setting at 0 and the 3803 Master Volume at 00, I would suspect a problem with the room.

I've never heard of anyone requiring more than 1/2 gain on the sub amp to reach 78 dB even in large rooms. The SVS plate amps are very sensitive to input voltages, which in turn requires much less gain at the amp. I've heard rumor they will actually be making the low level inputs a bit less sensitive in the future exactly for this reason. Heck, the gain setting on my 20-39PC+ is only about 1/4 and I'm running the sub 4 dB hot!

He may likely find after he experiments with placement that his old calibration setting at the sub amp will be too high.

I think the important thing to remember on sub calibration is that the sub level at the meter is dependent on 3 variables: 1) the internal sub setting on the AVR, 2) the Master Volume setting on the AVR, and 3) the gain setting on the sub amp itself. Any one of these settings is irrelevant without the other two for perspective and reference. That's why it is important to make sure we include the sub level setting and the Master Volume setting when discussing the relative significance of the sub plate amp gain setting.

Regards,

Ed

 

[Willem Vos]

Heck, the gain setting on my 20-39PC+ is only about 1/4 and I'm running the sub 4 dB hot!

Hmm, that's very low for the gain setting. (Compared to me, that is)
What is the sub-level on your receiver?

I've also read that voltages outputted through the pre-out vary from receiver to receiver. Apparently denon receivers put out a very modest voltage, which would result in having to set the gain on the sub a lot higher than with other receivers.

I have my gain a little over 1/2 way. Without BFD EQ'ing I can leave it at 1/2. The sub level is set to -6dB. It's calibrated at approx. 78dB.

 

[Edward J M]

Not true about the Denon. I also have the 3803 and my settings are:

sub level: 0
mains level: -3
Master Volume: 00
Sub gain setting: about 1/4
mains calibration: 75 dB
sub calibration: 78-79 dB

I have found with the 3803 (at least mine anyway), I need to run the internal sub level setting a few clicks above the internal mains setting in order to achieve the proper bass response. I know, it's weird but it's true. For more info, chase down that "3803 bass management" thread over in the receiver/amp section.

Since I am running at sub level 0, that would account for the lower gain setting at the SVS plate amp as compared to yours, since you are running at -6.

Regards,

Ed

 

[Willem Vos]

Thanks Ed.

I think I read your thread already...(already a bit hazy though) something about a bass management bug in the 3803.

I have the 3802, so I'm not sure if it has the bug.
Worth a try setting the sublevel above the mains...(I hope I remember to lower the sub-gain first, though )

The -6dB setting I have now is just for the cleaner signal it is supposed to give.

Regards,
Willem

 

[Larry Marq]

Hey guys,

Sorry for the ambiguity...

Yeah, I reset sub gain to acheive 78db after each receiver adjustment. You are correct Ed, when you suspected I was checking my BM (so to speak ). There is a close opening to the sub. It stays very close to 1/3 gain whatever I do.. When using AVIA LFE sweep the meter is all over the place. Gotta go for now...My anniversary and I'm already in trouble for getting the sub , so I'd better go! Be back Sunday...

Later, Larry THANKS!