Pulled the trigger today! SVS20-39+ on its way! (1 Viewer)

[Juan_T]

Hi Guys, back again! =)

OK! Im done mapping my room.. now how can I post my graph here?!

I have a few peaks, 2 small peaks at 22Hz and 40Hz and a 2 huge dips at 50Hz and 89!

After having calibrated my system, I set the volume a -25 on my receiver and started the low Hz test tones.. from 15Hz all the way up to 160Hz, and I graphed them vs DB.
Is that the way to properly do it? set at -25? Also, the way that I calibrated my system pre-sub mapping was thru the internal DENON AVR 3802 test tones.. Does anyone know what HZ the test tones are at? I cant get my Video/Audio Essentials DVD to work on my player.. =( so I had to set it up with my Receiver.

I took readings quickly and rested the sub, and moved on through each track on the CD. The highest Db was 94 (With the radio shack correction vals), so I'm assuming I did not damage my sub.

I'd like to post my chart, so I can get some feed back. Any tips?

btw,
got Titan A.E. the bass is awesome!!! =) got it for 5.50 at Target. The movie is ok, the visuals are a 10 and the sound is also a 10.

 

[Edward J M]

Juan:

You need a website to host the image. You need to grab a screen shot from the spreadsheet, upload it to a website, and then hotlink it to HTF in a post.

Ed

 

[Juan_T]

Thanks Edward!

Could someone host my graph?

I would like some professional opinions from you guys! I'd like to know if I need an equalizer, and if I do, which one to get!

Thanks!

:wink:


ps
"After having calibrated my system, I set the volume a -25 on my receiver and started the low Hz test tones.. from 15Hz all the way up to 160Hz, and I graphed them vs DB.
Is that the way to properly do it? set at -25? Also, the way that I calibrated my system pre-sub mapping was thru the internal DENON AVR 3802 test tones.. Does anyone know what HZ the test tones are at? I cant get my Video/Audio Essentials DVD to work on my player.. =( so I had to set it up with my Receiver."

Anyone?

 

[Edward J M]

When I was running manual sweeps using that technique, I would set the upper tones to around 80 dB as a baseline and then evaluate the transition from mains to subwoofer.

Since your AVR imposes a 2nd order high pass filter on the mains, and a 4th order low pass filter on the subwoofer, the likelihood is low that you will obtain a smooth transition to the subwoofer in the crossover bandwidth (60-90 Hz).

Your first priority should be to roughly match the level of the subwoofer (in the 20-60 Hz region) to that of the mains (in the 60-160 Hz region). After that, start messing with the phase control on the SVS (in maybe 5 degree increments) and select the phase setting which gives you the smoothest overall frequency response. You might find that the phase setting has a significant effect on certain peaks or nulls in your curve. The continuously variable phase control on the SVS products is a nice feature IMO, providing quite a bit more flexibility than the 0/180 switch.

If you still are having trouble obtaining a smooth curve, then experimentation with placement (WAF be damned) is crucial. Subwoofer placement is probably one of the most underrated factors in obtainig the best possible bass response in your room.

If phase and placement don't get you an acceptable FR, then a PEQ (like the BFD) can help to tame peaks and obtain a "house curve" (do a search for the term and seek out Wayne P. for more guidance on house curves). Boosting true rooms nulls is typically met with limited success, and this practice is generally frowned upon; nulls are better handled by placement experimentation or by moving the listening position.

If you cannot get DVE to work with your player and AVR, you have some set-up problems. Make sure your player is set to bitstream and you are using a digital coax interconnect and your AVR is seeing and decoding a Dolby Digital signal incoming from the player. Also make sure any dynamic range compression circuits are off in the player and in the AVR. Set the LFE channel (".1") level (not to be confused with the subwoofer level setting) in the AVR to 0 (maximum).

Regardless, DVE has an encoding error in the subwoofer signal, and most users find that around 87 dB works well as the initial setting (the other 5/6 channels need to be set to 75 dB). YMMV but I think it's not a bad starting point. Your FR graphs will give you a better picture of what the sub is doing in the room anyway, than by simply relying on DVE to set the sub level. DVE will be more useful for balancing the other channel levels, and for video calibration.

Ed

 

[Juan_T]

ok, this is a test.. just trying to post an image.

Heres my system, when I get back home I'll post my graph.

Notice how my sub is "hidden" behind a decorative ladder.

 

[terence]

It worked, real clean.

 

[Juan_T]

ok! here it is.

What do guys think? Is it pretty bad? You guys see the big dips.. or is this a pretty standard curve for a typical room? Are my peaks and drops pretty severe? I know that at 56Hz, my curve shows a big drop in Decibels.

Any opinions? or advice? thanks!

btw, cant moove the sub due to WAF, if this is pretty bad, I can try the other corner.

 

[Juan_T]

ok, since nobody replies.. I guess I do need to get an equalizer to raise those valleys.

Is a ART 351 what I need? Ive also heard about those feedback destroyers.. I looked at the ART 351 but the resolution of adjustability in Hz goes by 5 Hz.

not sure.. what do you guys suggest?

 

[Juan_T]

Does my graph warrant an equalizer??

 

[Robb Roy]

Juan,

I would first try the other corner. If that dip is not a null, an EQ might help, but generally speaking, reducing peaks is better/easier than boosting dips.

-Robb

 

[JohnSmith]

Your graph looks very similar to mine- 20-39 PC Plus too (20hz in pink, blue in 16hz tune)

http://nathansilly.012webpages.com/graph3.jpg

Trailing off under 20hz.
Peak ~22hz-25hz
Dip at 32hz
Big valley ~56hz.
Rising back up ~80hz.
Then trailing off (xover set to 80hz)

 

[Robb Roy]

Juan,

My guess would be that you're actually seeing a *very* slight peak in the 20-25 Hz range, and that you're not really dropping off until closer to 18 Hz (both due to room gain). Pretty much what you'd expect with room gain and a sub tuned to 20 Hz.

Your FR is actually good if you exclude those two large dips, and as I said, placement's probably your best option. Try the other corner, and if that doesn't work, try an EQ (since you said no other options are available to you). If those are true nulls, an EQ won't help, but it can't hurt to try once you're out of placment options.

-Robb

 

[Juan_T]

Thanks for the reply Robb, I will try to move it around to the other corner.. Hopefully my wife wont mind.. :frowning:

JohnSmith, I don't think your link is working right.

Im going to move it a few inches away from the wall, and plot another graph and see if it does anything to the curves. Then I'll try the other corner.

later!:b

 

[Robb Roy]

Juan,

As little as a few feet, and sometimes as little as a few inches, can make a big difference in frequency response, so if you've got some wiggle room before your wife loses patience, you're making the right call in trying that first.

-Robb

 

[JohnSmith]

Copy the link to IE, then press enter. Do not click on the link otherwise it'll come up with hot linking error.