Axiom Home Page Forums General Discussion Home Theater Sub Choice...

Thanks! I was starting to panic there.

alright let's try this out

http://i724.photobucket.com/albums/ww241/thefwam/subgraph.jpg

Thanks for the graph Steve. Is this a measurement of just the sub or the sub + mains?

Just the sub. it's normally crossed over at 80 Hz but i just fed the signal directly into the sub. So i suppose it's not as bad as it could be. Looks like I may need to run audyssey again to get those lower freqs raised a bit. the carpet has changed everything. Thoughts anyone?

HAY - how do you get the picture to post in the forum as opposed to the line?

Should I include the mains?

Usually the process in 'tuning' the room is to start with the sub by itself The idea is to see a response that is rougly in line with the curve shown by the blue line in your graph.

Once you are happy with the sub, then look at and work on the integration between the sub and mains.

For looking at a sub response to see what it really does vs. the marketing specs, just the sub is fine.

I would engage the crossover and measure the sub again. It will show give you a better picture of the both the sub's and the room's response.

By the way, if you want to adjust the scale of the x and y axis, there is a button on the top right of the rew window that lets you do that.

Edit: is that a 10 or 12" sub?

Another thing you can do to see how the sub response varies in the room is to do the sub crawl and put the mic where the sub sounds best to you and see how that measures. That may give you a target to aim towards for your primary listening positions.

... or if you want to get totally geeky like me, you can start measureing in a grid pattern over a larger part of your room.

12" sub. I may have to do the crawl again...when I put the sub where I sit and moved around the room I couldn't hear the sub anywhere. I tell ya, i'm all out of sorts right now. I think the volume may have been too low. The carpet's biggest change seems to be just attenuating those lower freqs quite a bit, so it's way out of wack when the higher freqs (right around 80 Hz) come into play.

Carpeting isn't nearly thick enough to absorb anything as low as the sub produces. From your graph it sure looks like the bass below 50Hz has gone missing. With a decent sealed 12" you sould get good extension down to 30Hz or below.