My Hsu VTF-2 graphs

First off, a thank you to everyone here at the shack. This is awesome stuff and the price is right. Nice job with the help files and guide, no problems here using a RS. I have an ecm8000 too and I was able to use both mics and got similar results.

OK, so here's my first measurement with REW. This is a Hsu VTF-2 with ports plugged.

I've got this in a small room (15x8x10ft). The room is treated with nine 4x2 ft 4" ocf 3.0 fiberglass panels.



So how's this looking? What about that hole at 45hz? That's a pretty big gap from 45 to 70.

[brucek]

I have an ecm8000 too and I was able to use both mics and got similar results.

Perhaps you could help us out then.

Could you tell us which RS meter model you have and its serial number?

I don't know if you've read this thread or not, but we are trying to establish when RS changed their meter response. Can you also tell us which calibration files you had loaded for the ECM8000 and the RS meter?

So how's this looking? What about that hole at 45hz? That's a pretty big gap from 45 to 70.

You can raise the gain of the subwoofer amp a bit and cut with the BFD from ~25Hz-40Hz and also from ~55-80Hz. First though, you should take your response with the sub only and the crossover engaged...

brucek

I bought the RS SPL about two years ago. It's an Analog V2, 33-4050.
On the calibration files I used newrsanalog.cal for the rs and 'Mic Cal typ Behr ECM8000.cal' that came with trueRTA.

In the graph below, the green is the RS and the other two are ECM8000.

[brucek]

Perfect, the RS meter and ECM look very close (they only need +/- trace offset to match). Exactly what we hoped for.

Now if you could tell me the serial number inside the battery case.

It will be something like Q.C 12A05 TEC

brucek

[Sonnie]

privateradio wrote:

On the calibration files I used newrsanalog.cal for the rs and 'Mic Cal typ Behr ECM8000.cal' that came with trueRTA.

I'd be interested in seeing the 'Mic Cal typ Behr ECM8000.cal' file if you don't mind opening it up with Notepad, then copy and paste it here.

Thanks... and welcome to the Shack!

[lovingdvd]

Is this post or pre calibration? I am getting ready to calibration my VTF2.3 and am hoping I can get between 20-80hz with +/- 3dB. Is such a result possible? Currently I have a peak of about +4db at 25hz and +12dB around 30hz which I hope to be able to flatten out. Thanks.

[brucek]

I am getting ready to calibration my VTF2.3 and am hoping I can get between 20-80hz with +/- 3dB. Is such a result possible?

Certainly - Here's my equalized sub with house curve.....



brucek

BruceK: I'll get back to you with the QC for the RS. I don't have it handy right now.

Sonnie wrote:

I'd be interested in seeing the 'Mic Cal typ Behr ECM8000.cal' file if you don't mind opening it up with Notepad, then copy and paste it here.

20.0000 -0.07 31.9
25.1785 0.137 25.8
31.6978 0.275 20.2
39.9052 0.393 16.2
50.2377 0.344 12.3
63.2455 0.534 9.23
79.6214 0.512 6.47
100.237 0.493 4.27
126.191 0.358 3.03
158.865 0.407 0.06
200.000 0.114 -1.7
251.785 0.295 -3.1
300.640 0.204 -3.1
312.495 0.170 -3.4
324.817 0.136 -5.0
337.625 0.103 -4.2
350.938 0.073 -2.4
364.777 0.047 -3.6
379.160 0.021 -4.2
394.111 -0.00 -2.3
409.652 -0.01 -2.8
425.805 -0.01 -3.5
442.595 -0.01 -1.7
460.048 -0.02 -2.7
478.188 -0.02 -2.5
497.044 -0.02 -1.6
516.643 -0.02 -3.0
537.016 -0.02 -1.3
558.191 -0.03 -2.6
580.202 -0.04 -1.5
603.080 -0.05 -2.2
626.861 -0.06 -1.4
651.579 -0.06 -2.1
677.272 -0.07 -1.0
703.978 -0.07 -2.1
731.737 -0.08 -1.0
760.591 -0.09 -1.4
790.582 -0.11 -1.5
821.756 -0.12 -0.5
854.160 -0.12 -0.8
887.841 -0.11 -0.9
922.850 -0.08 -0.1
959.240 -0.04 0.22
997.064 -0.00 -0.1
1036.38 0.019 -0.5
1077.24 0.034 -0.8
1119.72 0.043 -0.7
1163.87 0.049 -0.7
1209.77 0.051 -0.8
1257.47 0.041 -1.1
1307.05 0.011 -1.3
1358.59 -0.04 -1.5
1412.17 -0.11 -1.2
1467.85 -0.15 -0.5
1525.73 -0.16 0.07
1585.89 -0.14 0.08
1648.43 -0.12 0.40
1713.43 -0.10 1.24
1780.99 -0.03 1.39
1851.22 0.116 2.27
1924.22 0.301 1.57
2000.09 0.448 0.89
2078.96 0.484 -0.4
2160.94 0.433 -1.8
2246.15 0.300 -2.8
2334.72 0.098 -3.3
2426.78 -0.17 -2.8
2522.47 -0.35 -1.4
2621.94 -0.41 0.85
2725.33 -0.14 3.37
2832.79 0.370 3.63
2944.49 0.682 1.43
3060.60 0.765 -1.4
3181.28 0.437 -3.8
3306.73 0.049 -3.7
3437.12 -0.23 -2.2
3572.65 -0.24 0.51
3713.53 0.035 2.42
3859.96 0.476 2.65
4012.16 0.803 0.25
4170.37 0.729 -2.8
4334.81 0.295 -4.1
4505.74 -0.01 -2.2
4683.41 0.072 0.40
4868.09 0.528 1.04
5060.05 0.747 -0.6
5259.57 0.813 -2.3
5466.97 0.653 -3.4
5682.54 0.589 -3.2
5906.61 0.635 -3.0
6139.52 0.763 -4.1
6381.62 0.624 -5.0
6633.25 0.475 -5.3
6894.82 0.428 -3.2
7166.69 0.978 -3.4
7449.29 1.015 -6.3
7743.03 0.913 -7.7
8048.35 0.764 -9.0
8365.71 0.691 -8.6
8695.58 0.767 -9.8
9038.47 0.588 -10.
9394.87 0.590 -11.
9765.33 0.493 -12.
10150.3 0.390 -12.
10550.6 0.464 -13.
10966.6 0.245 -14.
11399.1 0.180 -16.
11848.5 -0.25 -16.
12315.8 -0.13 -16.
12801.4 -0.44 -17.
13306.2 -0.44 -17.
13830.9 -0.72 -18.
14376.2 -0.82 -18.
14943.1 -1.08 -20.
15532.4 -1.29 -20.
16144.8 -1.64 -21.
16781.5 -1.90 -21.
17443.2 -2.35 -21.
18131.0 -2.70 -21.
18845.9 -3.12 -21.
19589.1 -3.57 -20.
20361.5 -4.01 -18.
21164.4 -4.46 -16.
21999.0 -4.92 -15.

[brucek]

privateradio,

Your sub response graph extends down to 15Hz, yet your cal file for the ECM8000 only goes down to 20Hz?

I found Sonnies ECM8000 calibration file to be quite consistent with other ECM8000 calibration files I found floating on the internet. These were files professionally created. You might want to consider using that one instead of the one you're using. It extends to 10Hz...

brucek

BruceK:

Thanks for the tip.

The reason I'm using the one with trueRTA is it was the first one I found. A suggestion would be to include these with the installation zip. Where do I find Sonnies?

[brucek]

A suggestion would be to include these with the installation zip.

Don't understand?

Where do I find Sonnies?

In this sticky thread or you can just click here

brucek

Brucek:

What I mean is that it would be handy to have the common .cal files(rs & behringer) in the REW download. It wasn't obvious to me where I find these. Thanks for the links.

[Sonnie]

I think you are suggesting that we could include the ecm8000.cal file with the REW install files.... or built into REW. That's an idea.

Thanks for the .cal file.... I wanted to compare it with mine.

Here's a comparison from 20Hz -22KHz... limited to your corrections. The dotted is yours and the solid is mine. Quite a difference really...

That is interesting. Sonnie, is there a way in REW 4 to re-plot with a different cal file?

[brucek]

Quite a difference really

Yeah, I thought so too. When I went looking to compare ECM8000 files that were done professionally I found most were within ~1dB. I felt I could easily suffer 1dB in positional movement of my microphone or sneezing for that matter. So, I decided to simply use your file sonnie. The ECM8000 all seem to be quite close in response. That True RTA one is strange, especially in the octave spacing they chose.....weird.

brucek

[JohnM]

privateradio wrote:

is there a way in REW 4 to re-plot with a different cal file?

Yes, just load up the different cal file and hit "Apply Windows" from the IR Windows dialog to recalculate the response with the new cal file.

[lovingdvd]

brucek wrote:

Certainly - Here's my equalized sub with house curve.....

Attachment 1848

brucek

Nice! That tracks beautifully along your house curve. I was wondering though why you have it slopping fairly steeply well before 80hz?

I'm new to this but was thinking I'd use a house curve that was a little high at 20ish and then flat from 30-80hz. But after seeing your graph I am wondering if my plan is not a good one... ?

[brucek]

was wondering though why you have it slopping fairly steeply well before 80hz?

I use a 60Hz crossover...........

[lovingdvd]

brucek wrote:

I use a 60Hz crossover...........

Thanks but I'm still a bit confused. At 50hz it looks to be about -10dB and at 60hz about -15dB compared to the 20-40 range. I though the goal was to get things flat? Or in some cases I read where people want to boost the lower frequencies a bit more. But I'm trying to understand why you'd want that type of rolloff well before the cross over point. I'm sure you have a good reason and I'm just questioning this so I can understand the "why" and apply it to what may work best in my room. Thanks.

brucek wrote:

Now if you could tell me the serial number inside the battery case.
brucek

Brucek, mine is RS V2 33-4050, QC 04A04 TEC

OK, I moved my sub and remeasured with both the RS and the ECM8000. This time I went thru my AVRs xover. These are pretty close so I'm confident I have accurate measurements. Thanks for the help.

I'll be back when the BFD arrives.

Green is RS with newrsanalog.cal, Yellow is the ECM8000 with Sonnies ecm8000.cal file.

[brucek]

Thanks but I'm still a bit confused. At 50hz it looks to be about -10dB and at 60hz about -15dB compared to the 20-40 range.

That's what a 60Hz crossover looks like. When the sub has that type of output and the mains have a similar 60Hz crossover they combine to produce a flat output.....

See below:
This shows three responses on a single graph. An 80Hz crossed sub output and a mains 80Hz output response and then the final flat resultant response...



brucek

[brucek]

Green is RS, Yellow is the ECM8000

privateradio,

Is this graph with the ECM8000 cal file from Sonnies mic?

[lovingdvd]

Thanks! Makes total sense. When I use REW, will I tell it what my crossover is and it adjusts the target/reference line automatically to provide this rolloff for the sub channel?

[brucek]

When I use REW, will I tell it what my crossover is and it adjusts the target/reference line automatically to provide this rolloff for the sub channel?

Yes...