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Discussion Starter · #1 ·
Here are my first graphs.
Are these any worse, or much worse from the average bears?
One is just the sub, and the other is sub + mains.
The sub is about to get a couple passive's screwed onto it's sides, in short order.
I just wanted a before and after plot to start!
But, I can't help but feel those large divits are from the room, where there is very little I can change. (according to the boss)
My one question right now is, will the passives on either side of the sub cabinet change the ROOM response much? Maybe since they are propagating 90* to the left and and right of the driver? I realize the passives do not do much above 50hz anyway...
 

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Discussion Starter · #4 ·
Here is the passives reference.
It better not lower the output!
http://www.hometheatershack.com/forums/diy-subwoofers/15971-about-go-into-sub-surgery.html

Sorry about the title.

The room is the bottom half of a small raised ranch. Across the middle ceiling is a 4 foot wide by one ft tall duct/ main house beam. I really think that is setting up a weird room mode.

But if you look at the position of the sub in the corner, and picture passives mounted on the each side, I was wondering if maybe they would affect the room mode/node. I am thinking though, that the wave is so long, that it won't matter much.
 

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Discussion Starter · #8 ·
Yes, sorry. Passive radiators. The cabinet is going to be about 2.9 cubes with them in (3.1 now) and each radiator will have about 1600 grams on it, tuning the cabinet to about 18hz. It should give a bit more low end punch/headroom.
Here is a graph I just did about 5 feet away from the first one. Not a normal listening position however.
 

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Discussion Starter · #11 ·
I moved the mic to about 4 feet in front of the listening position.

Here is another curious problem:
Looking at these two plots, can you tell which one has better phase with the mains?
I ask because I have a rather weird amp, an audiosource amp7, a tripath digital amp, that is said to have an inverting output. I then hooked up the sub inverted, to match it. In what I thought was "in phase" wiring, the output seems higher down low, where the mains don't have much response. (Actually, in this case, just one main). But the plot looks better (I'm guessing) with them wired out of phase...

I'm so confused...
 

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Discussion Starter · #14 ·
What freq should I match the mains at?

Or to put it another way, how do you match the mains?

EDIT: The post 11 above shows both graphs with the mains on, just regular (?) and inverted sub hookup.

I really appreciate all the tips I can get. I have been playing with this thing now with *many* different combos, bassis settings, etc.
 

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Discussion Starter · #18 ·


This was the result of playing quite a bit with it. To me, it seems almost too good to be correct. I turned the sub so that it faces the corner. Changed the sony to "small" in the speaker menu.

My receiver is an older 30es model. It has terrible documentation, I have no idea where they cross things at, it looks like about 60hz, but even with small selected I can get significant output on the mains at 40 hz?

I don't know what the new receiver will be, this one sure has worked great over the years, on every day, used and abused. I think one thing that really helps it live is having outboard amps though. The next one though WILL HAVE excellent bass management if nothing else.

I appreciate all the tips guys, great info here!

Edit: This was with 1/3 octave filter on. It may have hid a little sin, namely a very narrow dip at 38hz. I have to find some bass traps and play with them. WAF might be a problem.
 
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