Best way to calibrate to front of the room dual subs .

M

Mark E. Long

Audioholic
ok got a question for all is there a better to level match dual sub woofers than besides the built in text tone in my receiver a Yamaha RX-A 3020 when i try to set them with the test tone it jumps around so much it seems hard to get an even level to both .They are both in the front corners 16 feet apart it seems hard to get them the same with that built in tone . is there a test disc out there that is more consistent in tone to use .I am using two psw-1200 jbl subs 12 inch ported . i know there not the best but all i have for now
Thanks in advance !
 
mazersteven

mazersteven

Audioholic Spartan
Experimentation is the answer: Since there aren’t any guaranteed best spots when it comes to positioning multiple subwoofers, moving them around and listening for the changes is really the only way to get them locked-in with your lair. But if you have a rectangular room, you can use some general placement guidelines as starting points. Of course, your listening positions will also affect where in the room the subs sound their best. But once you’ve got that dialed in, check out some of the most popular dual subwoofer placement options below:



If you have a rectangular-shaped, dedicated theater room, multiple rows of seating, or just want excellent bass coverage, placing two subwoofers midway along the lengths of opposing sidewalls is the best recommendation. These locations yield the smoothest and most even bass distribution across the widest space due to something known as axial mode cancellation, thereby maximizing bass impact for the most listeners. You can also try placing your bass bins at opposing midwall points across the width if you can’t position them along the length.




No question, loading both subs in the front corners of the room provides the most bass. This is because doing so maximally excites all of the room’s resonances, thereby yielding more output for a given volume setting than ones that aren’t corner loaded. Moreover, you can lower the subs’ volume to increase headroom and decrease distortion. The downside is that corner placement can also provide too much reinforcement: Bass can sound boomy or uneven. If this happens, try bringing them out from the corners in small increments, starting with around one foot of space between each sub and each adjacent wall.




At this point you may be asking yourself, “Is it possible to get the best of both worlds, i.e. bass that’s a blend of both corner and midwall placement?” The answer is a definite maybe: Try positioning your subs along the front wall with their cone centers at the 1/4 and 3/4 distances of the room width. Rooms that are sympathetic with subs at these locations will yield almost as much bass output as corner placement but with a smoother overall frequency response. Of course, this reduces total output compared to full corner placement, but most quality subwoofers nowadays have more than enough headroom to compensate.




Unfortunately, we can’t always place our subs and our chairs in ideal parts of the room due to aesthetic or visual constraints: Many of us simply can’t remodel our room around these items, or have to deal with open floor plans, or irregularly shaped rooms, and the like. Luckily, there may still be a solution—opposite corner placement. Putting the subs in opposing front and back corners will maximally reinforce bass output like the front corners, but can also distribute more linear bass throughout the room. Try tweaking the subs’ positions little by little to see if there are sweet spots where the bass locks with the room. If you’re a bass freak, try this one even if you can do one of the placement options mentioned earlier: You may find this is your preferred bone-crunching, teeth-rattling option.
 
ryanosaur

ryanosaur

Audioholic Spartan
The Welti/Devantier approach is one way. It seems to work best in a truly symmetrical sealed room. I've not been a fan of this approach. (It also does not work in my room.)
Geddes' Approach is more open to any changes in the rooms acoustics that may affect placement. Toward this, he recommends moving subs off the front wall, especially if you have capable towers (true full range is better still) and looking for strategic asymmetric locations in the room.
I do this utilizing 2 subs. Larger rooms may require three. But at that point, you effectively have 5 LF sources, all working together to trigger as many room modes as possible.
I have yet to see anything that really shows the Welti/Devantier approach to account for any room irregularities. Frankly, at the point some suggest that Subs must be added in pairs, I find this to be a much more dogmatic approach that relies more on brute force to overcome acoustic problems rather than solve for them using strategy and finesse.
That's just me, I suppose.
Every room is different, mine included.

:)
 
M

Mark E. Long

Audioholic
Thanks my setup is set up just like the first but closer to the 1/4 placement with my towers inside of them . i get good bass but i am having a tough time leveling them so there both the same i get probably in there best location for my room even auto calibration has a tough getting them level matched volume wise . then i always recheck the levels with a spl meter . it just seems to jump around a lot even when just setting one its a strange warble tone to set a level too as it will move the meter as much as upto 8 deb when matching the other 9 speakers in the system they stay steady but this tone just jumps all over the place . Thanks for your input .
 
mazersteven

mazersteven

Audioholic Spartan
I think we talked about trying this. Next to your couch and table

AU_DS_opposing.gif
 
ryanosaur

ryanosaur

Audioholic Spartan
Thanks my setup is set up just like the first but closer to the 1/4 placement with my towers inside of them . i get good bass but i am having a tough time leveling them so there both the same i get probably in there best location for my room even auto calibration has a tough getting them level matched volume wise . then i always recheck the levels with a spl meter . it just seems to jump around a lot even when just setting one its a strange warble tone to set a level too as it will move the meter as much as upto 8 deb when matching the other 9 speakers in the system they stay steady but this tone just jumps all over the place . Thanks for your input .
This, I think is a matter of measuring LFs. When running Audyssey, my Subs are always a struggle to get in the "Green". Something changed in the way Aud. runs... they used to show a dB window that seemingly gave a little more wiggle room for that initial adjustment of the Sub Gain.
I've spent as much as 5 minutes sitting at one Sub just moving the gain by a micron until I got a stable window! :rolleyes:
The things we do for the love of sound.
:cool:
 
M

Mark E. Long

Audioholic
This, I think is a matter of measuring LFs. When running Audyssey, my Subs are always a struggle to get in the "Green". Something changed in the way Aud. runs... they used to show a dB window that seemingly gave a little more wiggle room for that initial adjustment of the Sub Gain.
I've spent as much as 5 minutes sitting at one Sub just moving the gain by a micron until I got a stable window! :rolleyes:
The things we do for the love of sound.
:cool:
exactly my problem getting them both the same level . i spent an ungodly amount yesterday trying to get them both the same lol . It seems the left is good but bringing the right up to the same level is next to impossible i even put a new battery in the spl just to eliminate for errors i like to tinker as most of us do this is the one calabration i just cant get one always seems louder than the other . I guess i am trying to match the gain to match on both subs as the ypao doesn't set the distance right either but gets the others within an inch every time .
 
WaynePflughaupt

WaynePflughaupt

Audioholic Samurai
What make and model SPL meter are you using?

Regards,
Wayne A. Pflughaupt
 
M

Mark E. Long

Audioholic
Wayne its a old radio shack analog its got to be 25 years old but hey it does what it supposed to . It works perfect on regulsr test tone sweeps but is giving me fits on the sub test noise . ive got a test cd that i use to set 31 band eq's i might try digging it out and try to use it on the sub levels kust to see how it is

Thanks for asking !
 
WaynePflughaupt

WaynePflughaupt

Audioholic Samurai
It's the nature of a pink noise signal to make a meter fluctuate like that. What I do is just mentally note the highest level it hits. Or the lowest - either one will get the same result for level matching.

Regards,
Wayne A. Pflughaupt
 
M

Mark E. Long

Audioholic
It's the nature of a pink noise signal to make a meter fluctuate like that. What I do is just mentally note the highest level it hits. Or the lowest - either one will get the same result for level matching.

Regards,
Wayne A. Pflughaupt
Thank You Wayne thats pretty much what ive resorted to it just seemed odd to me that the sub test wobbled in volume on the reading shows ill try it again when the wife is away she adds a certain amount of unwanted background noise to the mix when iam tinkering with the rig lol at least iam fairly sure iam not crazy on this issue now .

Best regards Sir .
 

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