that's kinda what I figured I'd hear.... bummer.
Only thought I have for you. Cut your OC703 in 6" strips. Go to home depot and buy some of the largest concrete tube they have, make 3 vertical equal cuts so you have 3 "cylinders" for diffusors per tube. Using thumbtacks or whatever is needed, put them unfinished on the walls so the top is about 12" from the ceiling -- alternating between diffusion and absorption with only a couple inches gap between them. Line each wall.
If that gives you "enough" and it makes your room livable, finish them however you see fit.
Move your speakers wider, and add some more toe-in. That will help reduce your sound bouncing directly off of the back wall. Whatever you do, you don't want your speakers 4'-5' from any wall surface. (google for room mode calculator if you haven't already)
What speakers do you have? aka, do you have horn loaded HF drivers? ribbons or dome? I'm obviously concerned with more than just a 250hz notch in your room.
Only thought I have for you. Cut your OC703 in 6" strips. Go to home depot and buy some of the largest concrete tube they have, make 3 vertical equal cuts so you have 3 "cylinders" for diffusors per tube. Using thumbtacks or whatever is needed, put them unfinished on the walls so the top is about 12" from the ceiling -- alternating between diffusion and absorption with only a couple inches gap between them. Line each wall.
If that gives you "enough" and it makes your room livable, finish them however you see fit.
Move your speakers wider, and add some more toe-in. That will help reduce your sound bouncing directly off of the back wall. Whatever you do, you don't want your speakers 4'-5' from any wall surface. (google for room mode calculator if you haven't already)
What speakers do you have? aka, do you have horn loaded HF drivers? ribbons or dome? I'm obviously concerned with more than just a 250hz notch in your room.
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Here is a are bad pix of my speakers. They have changed somewhat since these were taken. They are heavily braced JBL Barzilay cabs with the Lambda TD15X drivers, 350hz Edgarhorns with JBL 2441 CDs with Radian Mylar surround diaphragms, and Big *** Heils for tweets.
I am crossing at 500hz and 5khz. Although I just picked up a DBX active crossover and will go back to active and see what sounds best.
After reading a lot of good thinking here and thinking about how to approach this, I have prioitized it into three steps.
1. absorption panels to kill the 250hz resonence.
2. set up multiple subs to flatten the responce below 50hz or so.
3. deal with reflectivity, back wall, side walls, and ceiling.
I am crossing at 500hz and 5khz. Although I just picked up a DBX active crossover and will go back to active and see what sounds best.
After reading a lot of good thinking here and thinking about how to approach this, I have prioitized it into three steps.
1. absorption panels to kill the 250hz resonence.
2. set up multiple subs to flatten the responce below 50hz or so.
3. deal with reflectivity, back wall, side walls, and ceiling.
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Sub placement is kinda funky... very room dependent.
Try to get one sub off the floor (maybe up behind that louvered door), another one near one or the other front corner, and a third one (if you have it) halfway between front and back, preferably off the side wall if you can stand it... at least this has worked for me for 20 years or so
John L.
Try to get one sub off the floor (maybe up behind that louvered door), another one near one or the other front corner, and a third one (if you have it) halfway between front and back, preferably off the side wall if you can stand it... at least this has worked for me for 20 years or so
John L.
Thanks John. I had an idea when reading your post. I have two good subs one in each front corner of the room behind the speakers. And I have the makings of two more subs. What I though of was to make that big space through those louvered doors the back chamber for a third sub. I have two 12" sub drivers that I'v never used because they need at least 8cu ft to go low. If I make that opening into a baffle, and mount both drivers in it, that could work well......I think.
I did take measurements Face, but then send the OmniMic back to the owner and realized I did not save the graphs. But I do know that I have a room resonance at about 250hz.
uh uh
I tried the two front corners and it seems to exacerbate room modes, especially in the most common listening positions.
If you can move one of them out of a corner, especially on the open side(stairwell), about 3 feet out from the sidewall midway, it will fill in a huge suckout in the bass (at least it does in my room, 25' x 25' x two story).
I've had to kinda 'fake' the placement, because the absolute best location is too intrusive for the front subs.
Anything over 3 subs is sorta redundant (though it won't really hurt). I like to think of the subs as additional room modes I'm strategicaly placing at the suckout nodes to augment the room configuration.
Hope this helps
John L.
I tried the two front corners and it seems to exacerbate room modes, especially in the most common listening positions.
If you can move one of them out of a corner, especially on the open side(stairwell), about 3 feet out from the sidewall midway, it will fill in a huge suckout in the bass (at least it does in my room, 25' x 25' x two story).
I've had to kinda 'fake' the placement, because the absolute best location is too intrusive for the front subs.
Anything over 3 subs is sorta redundant (though it won't really hurt). I like to think of the subs as additional room modes I'm strategicaly placing at the suckout nodes to augment the room configuration.
Hope this helps
John L.
You don't only need to use the subs below 50Hz. The point of multiple subs is to increase the number of sound sources at low frequencies so as to smooth out the effects of room modes and the more the better. Obviously you don't want to use the subs up so high that can localise them, but using them up to 100Hz, so that they overlap with the mains is recommended.
I'll draw up the layout of the room and you will see that I am limited as to where I can place subs. I would "like" to keep the two subs in the front corner just for semitry's sake. This will be something I'll play will.
I agree 5th. As a matter of fact, my bass speakers sound tighter when I plug the ports, but then the F3 goes up to about 80. So having them plugged and running the subs up higher might sound better.
Here is another idea that came out of a discussion I had with a friend tonight. As I said earlier, I have a 4x4x3 foot storage space in the back of the room.....well, the floor of that space is part of the large storage space half the size of the house. So if I mount both sub drivers in the floor of the storage space and take the louver door off, I will essentially have an Infinite Baffle as a third sub.
Thoughts???
Here is a screen shot of the WT3 results for those woofers by the way.
Thoughts???
Here is a screen shot of the WT3 results for those woofers by the way.
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