Fincave's graph

**Fincave** · **05-25-06, 02:49 AM**

monolith.jpg
Alright, just downloaded the new excel workbook and this is the graph it gave me after using the old measurements and leaving the filters as they were. Will do some tweaking at some stage, not today as it is a holiday here and do not want to upset the neighbours. Will tackle REW as soon as I can get hold of a suitable soundcard that is not too pricey! Feel free to comment but please note this is not the final graph, changes will be made at some stage.

**Sonnie** · **05-25-06, 10:23 AM**

That really don't look so bad.

About the least expensive soundcard I've found for use with a lappy was the Creative SB MP3+.

**Fincave** · **05-26-06, 01:44 AM**

Quote:

Sonnie wrote:

That really don't look so bad.

About the least expensive soundcard I've found for use with a lappy was the Creative SB MP3+.

It looks ok, am curious to see what it will look like using REW. The Creative soundcard is the one I am looking at, nobody just seems to stock it here. Any idea if this one http://sounden.terratec.net/modules....rticle&sid=230 would be suitable as it is currently available?

**Sonnie** · **05-26-06, 09:27 AM**

It says it has stereo line input and output (3.5mm)... so it should work fine.

Yeah... that response could look totally differenct with REW.

**Fincave** · **06-08-06, 04:43 AM**

Ok, here are two graphs that I obtained using REW. Am not sure if I have done everything correctly but I did read the intstructions very carefully. All comments are most welcome and I will go back and do some more reading and testing tomorrow morning.

**brucek** · **06-08-06, 06:21 AM**

Quote:

Am not sure if I have done everything correctly

One of the tricks I've learned (to narrow in on problem areas after I've done an automatic sweep) is to select Sine Wave and then check the box below it called Frequency Tracks Cursor. Then I press the Play button and press the red SPL button.

Now as you slide the cursor along the graph, the sine wave frequency associated (where your cursor is located) plays through your system and reads out the SPL level on the REW screen.

This would allow you to move the cursor around that dip at ~52Hz and observe if it really dips that low. The SPL meter will verify this. If it's indeed a dip (and not some computer hitch), you then have the opportunity to dynamically move some things around in the room to try and correct it while you observe the REW SPL level.

brucek

**MikeOates** · **06-08-06, 11:09 AM**

brucek,

Just got to thank you for that fantastic tip, had no idea you could do that.

Mike

**brucek** · **06-08-06, 11:25 AM**

Quote:

had no idea you could do that

It's a great way to set up your phase control on your subwoofer.

After you do an automatic measurement (when you've added in the mains to check for interaction with the sub around the crossover), there's usually a dip or a hump around the crossover frequency.

Now use the frequency controlled cursor and move it over the most affected area and then turn the phase dial on the sub and watch the REW SPL meter. The goal is to match the SPL level you would like the hump or dip to be equal to. Now do another automatic measurement and see the results on the graph....

brucek

**Sonnie** · **06-08-06, 12:31 PM**

Yeah brucek... why haven't you put that tip/trick in the REW Tips sticky thread. You hogging it all to yourself?

uh-huh... being a bad little greedy feller huh? heehee

Of all things... I didn't even know this. My feelings are hurt that you didn't even share it with me until now.

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