Home Theater Forum and Systems banner

1 - 6 of 6 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter #1
Hey,
here I'm showing a few graphs, I'm not sure if I am doing this right.
The hardware list is the ECM8000 (with cal loaded) Xenex802 and the turtle beach external soundcard.

*note: I did set the graphs to the "standard" setup but it does not cut the graph off, I guess all it does is zoom in? I zoomed out to see the information*

1st I calibrated the sound card, loop to itself and got this graph shown. Next I did a sweep and got the second graph shown. I swept multiple times but they were all very close so I figured it was a good representation of the sweep.

Of note: I did the SPL calibrations with my radio shack spl metere but REW said I was getting clipping at 75db, I lowered the volume and it said no clipping but as you can see REW thinks I am getting 90+db. My lines dont follow the arch, (whatever that stands for) like others i've seen so I'm sure there is something off with these.

Thanks for any help.
 

Attachments

·
Registered
Joined
·
7,514 Posts
After you set the input level to the soundcard in the Check Levels routine, you forgot to press the Calibrate SPL button. This then matches the internal REW SPL reading to the real SPL meter you used when you st up ~75dBSPL at the listening position. Without it, REW has no reference. That's why your results are at 100dB...

For subwoofers, always use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - 200Hz) using the Graph Limits button in the top right corner of REW. For full range, use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - upper limits you desire, i.e. 20KHZ - certainly no higher than your soundcard can extend).
For full range, enable smoothing to eliminate the comb filtering. Use a 1/3 octave smoothing.

brucek
 

·
Registered
Joined
·
16 Posts
Discussion Starter #3
Thanks!
I'll give those a try today.
Since it was a full sweep, I think I just put it together that what people are posting (that follow that downward curve) are just subwoofer sweeps (I think) that is why it trails down and follows that arc?
 

·
Registered
Joined
·
7,514 Posts
what people are posting (that follow that downward curve) are just subwoofer sweeps (I think) that is why it trails down and follows that arc?
That's a target for subwoofers that is selectable to different crossovers. There are also full range targets and mains targets that can be set.

Hopefully, you have read and are completely familiar with the REW HELP files.

brucek
 

·
Registered
Joined
·
16 Posts
Discussion Starter #5
I'm trying :)
Its probably not much to you people that do this all the time but for us new folks understanding some of the speech and what we are looking at can be quite a handfull. I'm bashing through it though, slowly, but working it. I'm hoping to use my readings to figure out my room treatments needed.

Thanks for the help though.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #6
Ok,
When I set the levels, if I use the speakers I get a slightly different reading than if I set it by subwoofer. When checking REW levels between the speakers and subs it is a large difference on the mic (from -12 to -18 in REW). And to get these levels I almost had to turn my sub's gain 1/3rd down on each sub. I'm going to try setting everything by SPL again through an outside program to see if something has changed. In REW, using the tone test it SEEMS to be ok. Anythoughts? Is the mike more sensitive to speaker sound vs. sub sound?

Here are the two graphs I ended up with, can anyone help translate these to english for me :D
I have a cal file loaded for my sound card (turtle beach) and my mic, e8000 if that helps to read this.

Thanks!
 

Attachments

1 - 6 of 6 Posts
Top