first graph questions

[hot grits]

How is everyone. This is my first post and I would like to thank everyone for taking the time to help us all out.

I made my first graph of my sub eD A5-350 and im a little surprised at how steep it drops off at 30 hz. I was expecting a much better response between 20 and 30 hz. I have attached my graph. Could this be because of the frequency response of my soundcard, sub placement or am I doing something wrong?

[hot grits]

That graph is without audessey EQ on my receiver. This graph is with audessy enabled. It is still dropping off sooner than I expected. Do you think my main problem is sub placement?

[brucek]

Could this be because of the frequency response of my soundcard

Hopefully, you've gone through the calibration routine of the soundcard and taken a measure of a straight looped back cable from line-out to line-in, that should have resulted in a perfectly flat response. If you've done that, you know the soundcard is not at fault.

Yeah, sub placement is very important. Is it in a corner?

brucek

[hot grits]

brucek wrote:

Hopefully, you've gone through the calibration routine of the soundcard and taken a measure of a straight looped back cable from line-out to line-in, that should have resulted in a perfectly flat response. If you've done that, you know the soundcard is not at fault.

Yeah, sub placement is very important. Is it in a corner?

brucek

Yes i have done the soundcard cal and it is perfectly straight. The sub is in a rear corner behind the couch. I am going to try 2 other spots. I expected this sub to drop off at around 20hz not 30 hz. Thanks for any input, brucek

[hot grits]

The black solid line is my mic, correct? Does this look right?

[brucek]

The black solid line is my mic, correct? Does this look right?

Sure, as long as the file you downloaded matched the meter you have, then it's correct.

brucek

[jerome]

hot grits wrote:

The black solid line is my mic, correct?

Take a look at the legend behind the graph. What does it say?

I could tell you the answer but it's better if understand the different curves for soundcard and mic...

[hot grits]

yes it is the mic. Moving my sub helped the low end extension a bit. It really is amazing how moving the mic to different seating positions affects things. What do you guys mainly do, find the best spot for the sub when sitting in the main sitting position and let the chips fall where they may for the rest of seating area?

[brucek]

What do you guys mainly do, find the best spot for the sub when sitting in the main sitting position and let the chips fall where they may for the rest of seating area?

Well, most of us equalize with a BFD. This allows you to create one program for a perfect (selfish) sweet spot, and another that is the average over a wider area, so that everyone gets a decent response. You can also create programs for music and HT.

But you're correct, the response at one seating position is very different from another....

brucek

[hot grits]

Thanks, you guys are a big help. I plan on getting BFD sometime soon. Right now I am just trying to find the best spot for my sub. I will post some graphs of my results at different positions.

[hot grits]

ok, I tried a couple different spots for my sub. I made a few graphs at 3 different listening positions.

Main listening spot
Location A / Location B

[hot grits]

Next listening spot
Location A

[hot grits]

Location B

[hot grits]

Disregard the above posts. I had a little trouble uploading the pics. I will make a new thread to ask my question.

Sorry for the confusion.

[jerome]

You can just delete/edit your posts to correct your mistakes. By editing the first post, you can also change the thread name (if you wish to).

When it comes to sub placement, take a look at this one for instance:
http://www.hometheatershack.com/foru...ood-sound.html