AVS Forum

AVS Forum (http://www.avsforum.com/forum/)
-   Subwoofers, Bass, and Transducers (http://www.avsforum.com/forum/113-subwoofers-bass-transducers/)
-   -   setting up 2 subwoofers facing different directions? (http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1439963-setting-up-2-subwoofers-facing-different-directions.html)

n00b2 11-19-2012 03:40 AM

Hi

I currently have 1 sub facing the back in the front left corner, however bass feels a bit low in the room. Due to room limitations it isn't really possible to move the sub elsewhere apart from the back left corner where the bass response felt even lower. However I am thinking of adding a second sub and putting it in the back corner facing the right side which is where the bass feels low. My question is would this improve or make the sound worse? I could also have the back sub facing the front but then the 2 subs would be facing each other directly in line.

Thanks

4DHD 11-19-2012 07:51 AM

You can also stack the two subs, this will give a 6db gain. In fact I currently have my two subs stacked up front, with the top one rotated 90* from the bottom. That will save you on running a long line to the back.
In the HT I had from '97~'09, I tried many different sub locations, and I did not really like having a sub in back...but you can certainly try it.

ShaQBlogs 11-19-2012 08:17 AM

try a crawl and see if back is the best position.
with 2 subs you can get even bass through the room. I think Usually it is recommended to load in opposite corners. Thats how i have done with mine and it was much better than the sub playing in its position independently. Havent explored trying to better this

flickhtguru 11-19-2012 09:40 AM

What kind of sub do you currently have?

4DHD 11-19-2012 10:05 AM

Quote:
Originally Posted by flickhtguru View Post

What kind of sub do you currently have?
diy...JBL SUB1500 drivers in 2.5^3 sealed boxes with BASS digital amps.

ShaQBlogs 11-19-2012 10:30 AM

Quote:
Originally Posted by 4DHD View Post

diy...JBL SUB1500 drivers in 2.5^3 sealed boxes with BASS digital amps.
how good are these? Are they musical....tight?
how do they comp[are against infinity 1260, epic12, dayton reference 12 / 15?

I have a pair of 1260W...driving with Crown XLS

4DHD 11-19-2012 11:03 AM

Quote:
Originally Posted by ShaQBlogs View Post

how good are these? Are they musical....tight?
how do they comp[are against infinity 1260, epic12, dayton reference 12 / 15?
I have a pair of 1260W...driving with Crown XLS
The SUB1500 drivers were designed by Revel and built by JBL Pro. They were used in Revel's first sub, the sub15.
VERY musical, and they go very deep, to sub-sonic. I power them with 500w digital BASS plate amps.
Original, when I built them, I was using a Crown K2, 800wpc amp.

ShaQBlogs 11-19-2012 11:44 AM

any equivalents that u wud suggest available today, musical, one that goes deep and powerful?

Bill Fitzmaurice 11-19-2012 11:55 AM

Quote:
Originally Posted by n00b2 View Post

Hi
I could also have the back sub facing the front but then the 2 subs would be facing each other directly in line.
Sub bass frequencies radiate equally in all directions, so where they're concerned it doesn't matter which way the sub faces.

4DHD 11-19-2012 11:55 AM

Quote:
Originally Posted by ShaQBlogs View Post

any equivalents that u wud suggest available today, musical, one that goes deep and powerful?

I have not auditioned any subs in quite awhile, so not sure. The JBL HTPS400 is a very good sub, can be hard to find.
Although there is one auction on ebay now.

craig john 11-19-2012 02:10 PM

Quote:
Originally Posted by n00b2 View Post

Hi
I currently have 1 sub facing the back in the front left corner, however bass feels a bit low in the room. Due to room limitations it isn't really possible to move the sub elsewhere apart from the back left corner where the bass response felt even lower. However I am thinking of adding a second sub and putting it in the back corner facing the right side which is where the bass feels low. My question is would this improve or make the sound worse? I could also have the back sub facing the front but then the 2 subs would be facing each other directly in line.
Thanks
Adding a second subwoofer can be an excellent solution. As Bill Fitzmaurice stated, the direction they face is irrelevant as bass frequencies radiate omnidirectionally.

However, before you consider adding more subs, you should try to ascertain the problem causing the "low bass." If you are seated in a big null, (a cancellation caused by reflected sound superimposed on the original sound, and the out-of-phase waves cancelling the original waves), you may need to move your listening position to improve the sound. Try moving around the room while playing some heavy bass sounds and see if the amount of bass changes as you move. The center of the room is the worst place for bass response. If you're seated in the middle of the room, try moving the LP to either 1/3 or 2/3 of the long dimension of the room and see if the bass improves.

Another way to test would be to download the RealTraps Test Tone CD and play individual frequency tones as you move around the room. If the tones change significantly, you can determine what frequencies are being cancelled at your listening position:
http://www.realtraps.com/test-cd.htm

Once you determine if the problem is your room, your LP or your subwoofer, you can decide whether you need to optimize the sub you have or add more.

Craig

n00b2 11-19-2012 06:26 PM

Would stacking the subs and rotating one of them smooth the overall frequency response in the room or just increase the response on one side? I did a sub crawl and to me these 2 locations give the best response for bass out of 1 sub from all feasible locations. The other side is full of doors and windows making it impossible to put it there. Putting them side by side isn't an option either due to narrow front space. Craig John the problem I am having is that bass feels low on the side where there isn't any sub. Sounds fine on the side where the sub currently is. I have slimline speakers with the crossover at 120hz so I can kind of tell where the sub is coming from at higher frequencies. Would doing the option I was considering (putting it in same side back corner rotated sideways) provide a more smooth and even bass response or just amplify it on one side? I don't really want to fork out for another sub if it's going to sound worse due to poor room placement.

Bill Fitzmaurice 11-19-2012 07:31 PM

Quote:
Originally Posted by n00b2 View Post

Would stacking the subs and rotating one of them smooth the overall frequency response in the room or just increase the response on one side?
It will boost output capacity by 6dB but it won't fix room modes. Rotating one does nothing, read my first post.

4DHD 11-20-2012 04:21 AM

Quote:
The other side is full of doors and windows making it impossible to put it there.
I don't really want to fork out for another sub if it's going to sound worse due to poor room placement.
Well, can you move the sub long the side wall, away from the corner? Every room will provide different results, but subs placed at the mid-points of walls works quite well. And that might improve the overall room response.

n00b2 11-21-2012 01:51 AM

Yeh I guess I'll try putting it in the middle and see if that helps. Cheers

sputter1 11-21-2012 08:08 AM

Quote:
Originally Posted by Bill Fitzmaurice View Post

Quote:
Originally Posted by n00b2 View Post

Hi
I could also have the back sub facing the front but then the 2 subs would be facing each other directly in line.
Sub bass frequencies radiate equally in all directions, so where they're concerned it doesn't matter which way the sub faces.

However it can change your freq response. As little as 90 degrees could reduce a peek or dip.

Bill Fitzmaurice 11-21-2012 09:08 AM

Quote:
Originally Posted by sputter1 View Post

However it can change your freq response. As little as 90 degrees could reduce a peek or dip.
Not within the subwoofer pass band. Doing so would only affect above bandwidth harmonics.

4DHD 11-21-2012 09:57 AM

The best way to even out bass response, throughout the entire room, is to use two or more subs, placed in different locations.
And where those locations are, that is strictly room dependent.
In my last house in NV, the best two locations were right where the mains were. So I mounted the 3-ways to the tops of the subs. So the subs were symmetrical to the center seat position.
But in most rooms that will not happen. Placing sub at mid-wall points generally will produce good results.
Doing a crawl test will pin point those best locations.

sputter1 11-21-2012 01:22 PM

Quote:
Originally Posted by Bill Fitzmaurice View Post

Quote:
Originally Posted by sputter1 View Post

However it can change your freq response. As little as 90 degrees could reduce a peek or dip.
Not within the subwoofer pass band. Doing so would only affect above bandwidth harmonics.

It won't change the db level. It will change your graphed response as measured by REW.

Bill Fitzmaurice 11-21-2012 01:55 PM

Quote:
Originally Posted by sputter1 View Post

It won't change the db level. It will change your graphed response as measured by REW.
Only if so doing alters a room mode caused by the distance from the cone to a wall to shift. In most cases it will point out that the speaker was too far away from the wall to begin with, though with small rooms what might be seen is a shift in a null sourced by a rear or side wall reflection. Even when that's the case moving the mic a foot or two will give a different result, complicating the process of setting the EQ for best results in a wide area versus one spot.

sputter1 11-21-2012 02:30 PM

Quote:
Originally Posted by Bill Fitzmaurice View Post

Quote:
Originally Posted by sputter1 View Post

It won't change the db level. It will change your graphed response as measured by REW.
Only if so doing alters a room mode caused by the distance from the cone to a wall to shift. In most cases it will point out that the speaker was too far away from the wall to begin with, though with small rooms what might be seen is a shift in a null sourced by a rear or side wall reflection. Even when that's the case moving the mic a foot or two will give a different result, complicating the process of setting the EQ for best results in a wide area versus one spot.

You're correct, this works only for the lp. It's not a subsitute for multiple subs where you want to be more consistant over muliple seats.

P.S. I should also add that this isn't for a real null but rather a dip that could be easliy eq'ed out. Kinda a free eq if you follow me.

-edited for the p.s. smile.gif

n00b2 11-25-2012 07:20 PM

4DHD did you say you mounted your normal speakers on top of your subs? i thought that is a bad idea. I could do that to get subs on different sides if it doesn't cause other issues.

Bill Fitzmaurice 11-25-2012 08:39 PM

Quote:
Originally Posted by n00b2 View Post

4DHD did you say you mounted your normal speakers on top of your subs? i thought that is a bad idea.
Usually it is. Where subs sound best and mains sound best seldom coincide.

4DHD 11-26-2012 05:15 AM

Quote:
Originally Posted by n00b2 View Post

4DHD did you say you mounted your normal speakers on top of your subs? i thought that is a bad idea. I could do that to get subs on different sides if it doesn't cause other issues.

Quote:
Originally Posted by Bill Fitzmaurice View Post

Usually it is. Where subs sound best and mains sound best seldom coincide.

That can be true. But I present to you the JBL Performance Series PT800/PS1400 stacks. You would have to spend much more to get better. In the case of my last house, in which I designed/built a new room, with audio the main point of design, I stacked my custom L212 to my custom subs. I had tried subs in different locations, only to go back to the mains location.

Of coarse, using a PS stack does not mean one then can not add other subs, if needed or desired.
Here is a pic of the PS stack.

L212/SUB1500
dcp_0016a.jpg
PT800/SUB1500
dcp_0004.jpg

n00b2 11-26-2012 06:10 PM

That looks like a nice setup!. I'll try it out this way and see how it goes. Cheers.

4DHD 11-27-2012 03:54 AM

Quote:
Originally Posted by n00b2 View Post

That looks like a nice setup!. I'll try it out this way and see how it goes. Cheers.
Thanks, it was for 12 years, until I moved to Ecuador.
Notice all the space between the mains and the side walls, about 5 ft. Makes for a very wide soundstage. And being the mains were out from the back wall about 4.5 ft, quite deep as well. That room also had a vaulted ceiling to 10 ft, adding to the room's volume.
Where I am now, I've put the mains back on their 13" tall bases, which drops the mains about 9". And it works better for the soundstage, most likely cos of a lower ceiling. But there would be other reasons for that, like all concrete construction!
Although I have even more space to each side, about 9 ft, and a minimum of 5 ft to the back walls.

n00b2 11-27-2012 08:32 AM

Yeh if I had that much space on the front wall it would be good. Room shape and space is annoyingly restrictive in this house, though I have them out from the wall a fair bit. Ceiling height is also low in the house. M biggest problem apart from room constraints are gaps where the sound can escape. Too many doors and windows. Don't think there's any way to remedy that w/o blocking them is there?

4DHD 11-27-2012 09:58 AM

That is the case in most homes, systems setup in an open floor plan. Which is what I have now. But in this all concrete structure makes it much more lively than the room I showed, which was closer to neutral than either dead or live.
And in a live room, don't really need much volume.


All times are GMT -7. The time now is 12:06 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.