# Is this a good starting point for LF



## Cali (Feb 24, 2011)

Dark Blue line is front row
Blue/Green is rear row.

2 SUBS. I moved them around the whole room and measured, looking for the location with the least dips in response. Adjusting phase and re-measuring.

This is 0 treatments, 0 eq.

The 2nd graph shows all the measures as a cobbled mess.


----------



## bpape (Sep 14, 2006)

Looks pretty even between the 2 rows. Likely the big peak is a width mode assuming you measured at the center seat for each row. Peaks can be EQ'd down pretty easily but you'll also then be taking away from the more side seats. 

If you're going to have a peak, down in the bottom octave is not a bad place for it to be and pretty hard to address via treatment.

Bryan


----------



## Cali (Feb 24, 2011)

Thanks for the fast input!
Fuschia line is rear left seat. Interesting observation that peak is a width mode ( yes measures are in the middle).
I will move my mic to the sides/up/down to understand better.

As I understand EQing down is ok but boosting is a no no.
Given the nature of said peak, it this something Audyssey is capable of handling(sub eq is available) or should I look to acrquire independent eq?


Also when generating waterfall using the info in frist graph, what should I set the lower limit to?


----------



## bpape (Sep 14, 2006)

Manually adjusting with Audyssey should be fine.

Bryan


----------



## Cali (Feb 24, 2011)

Ok having audyssey perform some quick magic - I now have this.
Audyssey set my mains at 40hz, but in the chart below I have them turned off.
The dip at 51hz area appears to be height related. If I place the mic higer it dips more....lower it smooths out.

How does one address that? Ceiling trap? But where do u put it? Or do I try putting the subs higer?


----------



## bpape (Sep 14, 2006)

You can try the subs higher and see if you can get away with it. If not, then yes, ceiling panels over your head but they'll need to be pretty thick to get down to 50hz.


----------



## Cali (Feb 24, 2011)

Ouch- PJ is up there. Too much work( i think). Will try the sub's height.

Thanks for that fast response.


----------



## jim1961 (Apr 8, 2011)

Cali said:


> Ok having audyssey perform some quick magic - I now have this.
> Audyssey set my mains at 40hz, but in the chart below I have them turned off.
> The dip at 51hz area appears to be height related. If I place the mic higer it dips more....lower it smooths out.
> 
> How does one address that? Ceiling trap? But where do u put it? Or do I try putting the subs higer?


If your going to adjust mic height, and presumably listening height, be sure to do a full frequency analysis because you will find that other frequencies are affected. For instance in my case, raising the mic (listening position) a mere 2 inches caused a 6db lull at 600hz.


----------



## Cali (Feb 24, 2011)

I dont know what to say...I put those subs on my head and nothing changed...I swear!
Then I went back and moved one sub about 2ft and the dip went away. 
It really beats me.I'll be trying to build front corner traps this weekend. 24"*24" * 115"H


----------



## Cali (Feb 24, 2011)

I'm resurrecting this thread now since I actually have time to do some work.
I have set aside the corner area for triangular traps. I will be installing a masking system and the frame for it is about 6.5" off the back wall.

Free space(not including corners) is about 50ft*48" total.
I was thinking to do the normal linacoustic, but then I wondered, how about some 2" panels spaced 4" or 4" panels spaced 2" off the walls.

Is the front wall a place to attempt extra bass trapping? Is it worth it? i.e. is there much to trap around that area?


----------



## bpape (Sep 14, 2006)

Front corners are good. Balance of front wall not so much for bass control but should be covered with 1-2" absorption to address reflections from the surrounds off the front wall.

Bryan


----------



## Cali (Feb 24, 2011)

Traps finally installed. Bought from GIK- went with the KNAUF Ecose.

I cant wait to re-measure. I listened to some music and I hear a distinct- very distinct difference in my bass.
I will know how good my ears really are after I re-measure.

This trap is almost 12' tall- should I put a shelf in the middle so that the weight does not crush the bottom? Anyone built such huge traps with the Ecose?


----------



## bpape (Sep 14, 2006)

nicely done. You'll see a most definite improvement in the waterfalls down low with those.


----------

