Setting up two subwoofers--which method? - AVS Forum
Subwoofers, Bass, and Transducers > Setting up two subwoofers--which method?
dftkell's Avatar dftkell 03:55 PM 06-09-2014
I've spent a lot of time trying to position two subs in my small home theater. So far I have been putting them into dozens of combinations to determine the smoothest FR across my couch.

I have been placing them in various combos, running Audyssey Multi EQ and then measuring with Fuzzmeasure. This is pretty time consuming. I've put in a lot of hours doing this but still haven't found a combo that gives a nice smooth response. These are 18" DIY subs. Oddly, a positioning I had dialed in nicely with a pair of 10" DIY subs doesn't work as well when using the 18's. But I guess they are much bigger boxes that energize the room differently.

Now I'm wondering. Is the best way to find the best position for one sub first and then move the second to various spaces and measure each combo? Or should I be just putting them in various combos right off the bat and measuring. I also find that Audyssey can create a very different FR. So would you stop and run Audyssey each time or just wait till the best position of the bunch is found?

Basically this is a long winded way of asking what the most efficient way to ideally set up two subs would be. In the end I'm just a little frustrated that my FR's aren't as smooth as I had hoped.

Thanks,
Dan


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Bill Fitzmaurice's Avatar Bill Fitzmaurice 04:21 PM 06-09-2014
Quote:
Originally Posted by dftkell View Post

Is the best way to find the best position for one sub first and then move the second to various spaces and measure each combo?
Yes. The purpose of the second sub is to smooth response peaks and dips, mainly dips, that are there with only the one. Don't use room correction until after you get the best results without it.
spidey.joe80's Avatar spidey.joe80 04:40 PM 06-09-2014
That's a cool looking room. I would recommend nearfield placement. Like right behind your couch.
This should remove the room as much as possible. Also, this goes without saying but make sure your subs are in phase.
Good luck
derrickdj1's Avatar derrickdj1 05:43 PM 06-09-2014
One in a front corner and one in the opposite rear may work. Good Luck!
dftkell's Avatar dftkell 07:52 PM 06-09-2014
Quote:
Originally Posted by Bill Fitzmaurice View Post

Yes. The purpose of the second sub is to smooth response peaks and dips, mainly dips, that are there with only the one. Don't use room correction until after you get the best results without it.

Thanks Bill. I had been doing hours of putting the two subs in multiple configurations, then running Audessey each time and then measuring each time. Finding the best spot for a single sub first, then employing the second sub to further smooth the response makes more sense and should be more efficient time wise. Wish I'd tried that from the get go. smile.gif

Dan
dftkell's Avatar dftkell 07:55 PM 06-09-2014
Quote:
Originally Posted by spidey.joe80 View Post

That's a cool looking room. I would recommend nearfield placement. Like right behind your couch.
This should remove the room as much as possible. Also, this goes without saying but make sure your subs are in phase.
Good luck

Thanks. The speakers in my signature have just been upgraded as well. I'll be upgrading pictures soon. I'll definitely be trying near filed for a single sub and if that position is the best for a single, then I'll see where the second sub works best in conjunction.
kevings's Avatar kevings 07:55 PM 06-09-2014

Very cool loft....what a great use of a smaller space.

 

like another poster said, one behind the couch might work really well.  i have 3 18's in my room, all along the front wall, and having them like that has caused some peaks and nulls which i may have avoided with different placement ( room is option limited though )

 

also, the subs look great and go with your loft perfectly.  


dftkell's Avatar dftkell 08:00 PM 06-09-2014
Quote:
Originally Posted by derrickdj1 View Post

One in a front corner and one in the opposite rear may work. Good Luck!

I did try that and the results were okay but not great. I thought that would be a home run. But the room is very unique in it's shape so the results have been unpredictable. When I figure out a good configuration, I'll post some graphs.

Thanks
Dan
derrickdj1's Avatar derrickdj1 08:01 PM 06-09-2014
It would be interesting to see the graphs. What type of DSP do you use to EQ everything?
dftkell's Avatar dftkell 10:51 AM 06-10-2014
Quote:
Originally Posted by kevings View Post

Very cool loft....what a great use of a smaller space.

like another poster said, one behind the couch might work really well.  i have 3 18's in my room, all along the front wall, and having them like that has caused some peaks and nulls which i may have avoided with different placement ( room is option limited though )

also, the subs look great and go with your loft perfectly.  
Thanks. The subs in my signature are 10" Dayton DIY subs in a 1 cu/ft box. The 18's I built are also Dayton's in a 4 cu/ft box each.

I'm going to start by seeing what types of FR's I can get with a single sub behind the couch. I'll definitely include near field right behind. Then I'll try a single sub in the front parts of the room. Which ever gives me the best FR, I'll then integrate the second sub with it and see how good I can get it.
dftkell's Avatar dftkell 10:55 AM 06-10-2014
Quote:
Originally Posted by derrickdj1 View Post

It would be interesting to see the graphs. What type of DSP do you use to EQ everything?
I'd be happy to share the graphs when I'm through. I don't have any DSP or EQ. To be honest, that's a bit over my head. But I'd really like to learn more about it. I looked into a mind-dsp to try to learn how it works but it appears to be tied in with REW. I don't use REW and I'm 100% a MAC guy. So trying to learn REW and a PC is a bit much. Is there any thing else I could try? I hear people writing about Behringer EQ's but I don't know how I would use one. So right now, I would be finding the best spots, then running Audyssey, and then my Dayton plate amps allow me to adjust one band with PEQ.
dftkell's Avatar dftkell 09:28 AM 06-21-2014
Here are some measurements if anyone is interested. I'm using larger LCR's than in my signature. I haven't updated it yet. And the two subs are DIY 18" Dayton HO's in 4 cu/ft cabinets. The room is about 1,800 cu/ft with an open stairway. The ceilings are angled. Not really your typical room.

These are all measurements without Audyssey. Audyssey does help smooth out the sub's FR but at the same time it lifts everything from about 2kz and up. So it's a trade off and I'm not sure I like it. happy to post graphs of that as well if anyone wants to see.

So here are the graphs with no EQ.

The red FR is with one sub up front and another in the rear.
The blue FR graph is with both behind the couch.
The green FR graph is with one sub up front--same position--and the second sub in a different position in the rear.

I also included what the different sub configurations look like across the frequency range and how they look from 300hz down--about where the Shroeder frequency is.

Any thoughts are appreciated.

Thanks,
Dan

***I don't know why I can't get these pics to view as large pics. I can only insert them as attachments.
Attached: 1.png (43.5 KB)  2.png (48.1 KB)  3.png (48.6 KB)  4.png (54.6 KB)  5.png (63.5 KB) 
dftkell's Avatar dftkell 08:40 PM 06-21-2014
Here is what each FR graphs looks like after Audyssey is implemented. Audyssey is black in each graph.

Bass is improved for the most part. But there is now a tilt in the treble above 2kz.
Attached: 6.png (59.2 KB)  7.png (53.4 KB)  8.png (59.9 KB) 
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