Did I do this right?

up2youjoe

I have an SVS PB2-ISD still crated in the garage and I wanted to plot a graph on my PSW505 before I remove it so I did the following:

On my Yamaha RX-V1400 I went into manual setup and then sound menu and finally to speaker level. A static tone comes out from the front left speaker and I adjusted the volume on the receiver so the RS meter read 75 db. I then adjusted all the other speakers including the sub to read 75db.

I then put in the cd that I burned with the test tones from... http://www.snapbug.ws/bfd.htm and went down the chart and played all the tones on the spreadsheet and it plotted the following:

FREQ.........Raw SPL........Corrected SPL
16..............91.8..............103.3
18..............93.1..............101.1
20..............95.5..............103
22..............94.4..............100.9
25..............97.5..............102.5
28..............102...............106
31.5...........105.9............108.9
36..............107.5............110
40..............104...............106.5
45..............99.8..............101.8
50..............99.................100.5
56..............100.5............102
63..............98.2..............99.7
71..............95.9..............97.4
80..............104.8............106.3
89..............97.5..............99
100............102.8............104.8
111............105.1............106.1
125............107...............107.5
142.5.........98.................98.5
160............101.5............101



Does this sound right? Is it good or bad?


Thanks

POLKOHOLIC

how are you getting 103 dB with the 505 at 16Hz?

up2youjoe

"how are you getting 103 dB with the 505 at 16Hz?"

I don't know!!! Do I have the master volume on the receiver to loud?

I played the 16hz tone and the R.S. meter is placed where my head would be on the couch. The meter read 93(uncorrected) the first time(gain set at 1 oclock) and 91.8(uncorrected) the second time(gain at 11 oclock).

Does it sound completely wrong?

VR3

either completely wrong...

Or you have some KICK ****$ room gain...

LOL

POLKOHOLIC

Dude do you sit an inch away from the port?

gatemplin

That looks weird, I get pretty similar numbers with my sub but it is over 4 feet tall and like 14 cubic feet with a 15" driver. That response is not too bad at all.

up2youjoe

The room is 11x18x7h. The sub is corner loaded and the couch is 11 feet away in the middle of the room. I don't have a bad thing to say about the 505. I will plot the PB2-ISD tomorrow. Heck, maybe I should send the SVS back.

POLKOHOLIC

try rechecking your test tones and the rs meter. those numbers are impossible to achieve with the 505.

up2youjoe

Would lowering the volume on the Yamaha RX-V1400 make a difference? It was set on -5db

VR3

Well first off...

You're supposed to start at 83 db at 100hz for the correction factors to work right...

When you hit what? 100+ at 100hz...

up2youjoe

I just put the numbers into the excel sheet and it did the corrections automatically. I thought the 505 did not go down to 16hz so should I even here anything when I play the 16hz tone? Is there somwhere that has the proper instructions for this?

Thanks

Dr. Spec

Are you switching scales on the RS meter at any point along the way?

VR3

I stop *hearing* the tones at around 22hz..

The rest, the room just kinda falls apart...

Here is my graph -- I hit pretty strong to 15hz in my room

I have the SVS PCi 22-31, and my room is a 10.5x10.5x8

up2youjoe

Dr. Spec,

Yes, I change the scale on the meter. Does it sound like I am doing this right? The sub is on Berber carpet and on a concrete slab. The walls on both sides of it are also concrete. Next to the sub is the RTi8, then the TV then another RTi8 then the receiver rack and then the other wall. The only furniture in the room is the couch about 11 feet from the tv. I can try again, but I ran it twice allready. The first time I had the gain on the sub at 1 oclock and the db's were higher so I lowered the gain on the sub to 11 oclock. Maybe the 505 is better than people thought. I only wanted to run the test to learn how to do it so I can dial in the PB2-ISD I just bought.

Steve

gatemplin

Dont change the scale, leave it on C weighting.

pjdami

I think that gatemplin means don't change the scale on the graph. You do have to change the scale when going to different frequencies as the tone may max or min out the reading in the 10 db increments on the decibel meter.

Also use "slow" and "C" response settings on the db meter. Start off at 85 db (just for comfort and to protect the sub...those tones can be brutal on a sub.)

The Beyond.Gomer website for the 1/12 octave test tones is still unavailable. Send me a PM with a regular email address and I can send you the mp3 files to burn. I will have to make it multiple emails as the entire file is like 5 mb or something. I will send you the spreadsheet to use with those files as well.

Regardless, when you fire up the new sub you should hear a distinct difference in the character of the bass. I haven't heard a 505 myself but if it is anything close to the PSW350 or PSW404 then somethings unusual here especially if the gain is set at 11:00 o'clock (a safe level).

up2youjoe

I leave it set on C weighting and the response is set to slow. What I change is the "range" if the tone pins the needle. I assume that is allowed.


Steve

Dr. Spec

Sure, it's allowed.

I was just wondering if you somehow were misreading the meter on the different scales. It might explain the outstanding FR and deep extension.

Then again, SPL only tells half the story. The meter doesn't know if it is reading a true 16Hz tone, or mostly 32 Hz distortion fundamentals.

Maybe you really are reading everything correctly and you've got some hella room gain!

up2youjoe

Dr. Spec,

Then I'm I can only imagine what the PB2-ISD will sound like when I try out Darla and The Haunting. I really had a hard time buying the SVS because I was very content with the Polk PSW505. Maybe it is a very underated sub. No one has really done a shootout with it and an SVS and an HSU.


Steve

VR3

Trust me broham...

Even with your room gain -- there will be NO comparison. lol

up2youjoe

Well the SVS is pumping out some Pink Floyd as I type this. I can definatly FEEL a difference, and I have not set the phase yet or recalibrated anything. I'm gonna like this. Only problem I see is the SVS makes my RTi8's and my 65 inch Hitachi look small!!!

pjdami

Steve,

I sent you the files. Hopefully you'll get them okay. Had to split them up.

Other users have noticed some differences between the test tone websites. I doubt that is the problem here but at least repeating the process using a different method is a start to finding any problems.

pjdami

Well the SVS is pumping out some Pink Floyd as I type this.

Let me guess, "welcome to the machine" in WYWH or the helicopter track on the Wall?

up2youjoe

Roger Waters "Live in the Flesh DVD". Best $9 you'll ever spend!!!