Subwoofer experts please..again !! (1 Viewer)

[ling_w]

Re Ling’s suggestion to move the sub by the couch: There is no escaping boundary effects. Nearfield placement is usually the worse because it allows interaction with so many more boundaries, compared to corner placement.

Nearfield placement allows the direct sound of the sub to dominate the sound as opposed to room sound. With nearfield placement, you feel more of the sub impact, instead of the room boom.
It is a method that Bryston recommends one tries:
http://www.bryston.ca/newsletters/45_files/vol4is5.html

 

[Neil Joseph]

Note that when you switch to a rear placement, your subwoofer's phase would most likely switch to the 180 degree setting rather than 0 degrees. Lots of factors when placing subs. Just thank your lucky starts you are not rying to place 2 or more subs.

 

[JohnSC]

Thanks Wayne.

Does that mean that when using the sine waves recommended in performing the BFD analysis, we are risking damaging our speakers or doesn't it matter so much for short periods of time?

 

[Wayne A. Pflughaupt]

Does that mean that when using the sine waves recommended in performing the BFD analysis, we are risking damaging our speakers or doesn't it matter so much for short periods of time?

It only takes a few seconds to get a sine wave reading – no more than 5-6 seconds, which is not enough time to damage the sub. So sine away!

Regards,

Wayne A. Pflughaupt

 

[Jon Slater]

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Thanks for all your advice...Moved sub to top left of room behind frount left speaker, taken some more readings..this time sub only..
I value your opinions...Does this position look Better ?
cheers

 

[Ned]

It looks much better than the original readings. If you want to try lessen the remaining dip, test it in a few positions along the left wall.

 

[Jon Slater]

Thanks for all the help guys...

Ned, Theres not many places i can put the sub on the left wall.just after the frount left speaker is the fire place..then my tarantula ! And then back to where it was (briefly) before..behind seating position..

cheers

 

[Jon Slater]

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Another graph..this time sub and frounts..sub still in top left position..
Can anyone compare the above results with the blue line below..this was when sub was behind seating position..

I will get this right !!
Cheers

 

[Greg_R]

Double check your crossover settings (small & 80Hz on receiver, crossover _all_ the way up on sub). We shouldn't see a 6dB increase at 40hz when you add the mains. With the exception of the dip at 50Hz, you are +/-3dB from 30-80 (good for the PDR-10) w/o the mains.

 

[Jon Slater]

Hi greg..thanks for the reply..the settings are small and crossover on sub to top..
I am not sure which diagrams you are comparing..but the latest graph i have done is this one : Link Removed
I wanted to find out if it would be better to move my sub to behind the listening position, shown in the following graph as a blue line :

cheers

 

[ling_w]

Jon,

Regarding the 2nd plot. Was the sub right behind the seats or at the rear corner. From what I see, there is a big difference between those 2 positions.

Also, do you have your room dimensiona and your listening position from the front and side wall?

How about right behind the sofa, directly behind the center listener's position? Even nearer field and less boundary.

 

[Jon Slater]

Ling, The second plot (blue) was in the bottom left corner behind the listening position.

as for the room dimentions..The room is about 8 metres across from side wall to side wall. And about 10 meters from the window to back wall.

The listening position is about 1.5 meters from back wall and about 1.5 meters from the side walls.

cheers

 

[Leon Liew]

Hi Jon
My HT system positioning is exactly like yours. The
difference is that my equipment rack is at the left
corner wall thereby allowing me to almost centralise
the TV,front & centre speakers towards the sweetspot.
The positioning is that the door is in line with the
window therefore its 'almost centralise'.Its my living
room !(L21ft x W14ft x H9ft)
The system is 2.5ft away from the window which is laid
with thick curtains and my subwoofer placement is in
line with the right front speaker,firing towards the
sweetspot. The phase is set at 'O' for a more directional approach which I find very satisfying.
The 2.5ft parameter allows me to have access to the cables
& interconnects between A/V amp & DVD,CD & LD players.The
thick curtain acts as a buffer between speakers & wall so
that the bass has more punch. The sweetspot is about 8ft
away from the system and the suurounds are wall mounted,
2.5ft from ceiling to mounted position and distance approx 3ft from listening position towards sweetspot from L & R
But the final say is still oneself.If one is happy with
all the placement then it should be. Certainly I am happy
with mine.

 

[Jon Slater]

Ok guys..thanks for your help so far..heres my last graph...!!
firstly sub only
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secondly sub with amp in pro-logic mode
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I am still interested to here any comments and suggestions on these latest results...
cheers