room change and a large sub

rosconey · « **on:** 24 Apr 2004, 07:55 pm »

since my tempest pre is on the way i decided to get off my butt and make the move into the 2channel room.
the large isnt happy in it new location

i centered in the room so its between the mains.already tried putty adjustments.
going into the corner tomorrow when my back feels better-1 large sub140lbs,80#marble top,4 odyssey monos60#(extremes are heavier than standard

)and my diy mains at 80-90#each and my yamaha rxv1 for a pre 75#

lol
have to install mt 8th nerve corners also

rosconey · « **Reply #1 on:** 25 Apr 2004, 01:56 pm »

moved the sub into the corner and - bass up the wazoo again

zybar · « **Reply #2 on:** 25 Apr 2004, 02:32 pm »

Glad to hear it!

I have my two Larger subs up and running.

For now they are "near" the corner, but firing directly into my 40's (not sure, but I am thinking this is less than ideal).

Besides looking into different placement, I also have the Behringer DSP-1024 Parametric EQ that I will play with.

I figure this + ETF Acoustic Software should get me what I am looking for.

The last piece of the puzzle will be getting a good crossover so I can use the Larger subs in two channel as well as HT.

George

lkosova · « **Reply #3 on:** 25 Apr 2004, 03:13 pm »

George,

How do you like the ETF software???

Larry

zybar · « **Reply #4 on:** 25 Apr 2004, 04:26 pm »

Pretty cool and very powerful.

I wish there was a nice concise and well written manual, but I will figure out things over the next week I am sure. Ethan showed me the basics and I can usually learn things pretty quickly.

I need to figure out how to export the graphs. Once I do I will display some of my graphs.

George

lkosova · « **Reply #5 on:** 25 Apr 2004, 04:56 pm »

George ,

I would be curious to see how the largers respond when moved out away from the corners. I don't think they need help from the corner effect and might make a smoother response when pulled away .

If you have time try this and respond back with graphs etc.

Larry

zybar · « **Reply #6 on:** 25 Apr 2004, 04:58 pm »

Larry,

I agree with you, but I have limited places I can put them until I get longer speaker cable.

George

jgubman · « **Reply #7 on:** 25 Apr 2004, 10:16 pm »

I have 2 subwoofers and I found that I got a smoother frequency response when I moved them away from the corners and put them against the front wall in each of the room's 2nd order width axial mode (one sub at the 1/4 the room's width and one at 3/4). Luckily this placement also jibed pretty well w/ my best placement for my RM-40s (the 40s are just to the outside of the subs, and forward of them a few feet). So all the woofers are in phase and don't seem to be cancelling eachother very much.

Got the idea from Dr. Toole's white paper:
http://www.harman.com/wp/index.jsp?articleId=122

Harmon also had another white paper detailing an experiment on the "ideal" number and placements of subwoofers:
http://www.harman.com/wp/index.jsp?articleId=1003

In that experiment, they found that it was hard to beat putting one sub against the front wall's 1/2 mark and another (I *think* in phase, but I'd have to re-read to be certain) against the rear wall's 1/2 mark. They found this placement better than 4 subs, one in each corner, and as good as 4 subs, one on each wall's 1/2 way mark (as well as a number of different placements). I know John Casler also recommended this placement, unfortunately I have a RPTV against the front wall, so I couldn't experiment.

Anyways, YMMV, but it makes some good reading. I'm sure you'll nail down optimal placement w/ your ETF software.

bubba966 · « **Reply #8 on:** 25 Apr 2004, 10:20 pm »

I've actually had the best luck firing my subs into the wall with them sitting in the corner.

Not the best looking arrangement as I'm looking at the back of them all of the time. But they work better like that, so that's how they've stayed...

lkosova · « **Reply #9 on:** 25 Apr 2004, 11:13 pm »

Bubba,

M&K actually recommends this. I have done this also with good results.

Larry