# Sub-woofer/room tuning procedure?...



## Synergist (Nov 2, 2013)

To Whom it may Interest:

I am a dedicated audiophile/stereo-phile, with reasonably capable electronics/speakers, however, I have never elected to take the time to properly set-up/"tune" my system other than by ear...and now wish to get more precise in terms of listening position frequency response, phase, etc... Please forgive me if my questions
have been asked/answered multiple times, if so, please simply point me in the proper direction(s)...

Transducers: Stereo pair of Lipinski Sound L-707's
Stereo pair of SVS PC13-Ultra subwoofers (tuned to 16Hz., (2 ports blocked)) 

Crossover: Marchand Electronics XM44-2 (Linkewitz-Riley filter design, x-over point 60Hz., 12dB/oct. slope high & Low pass filters summing to resultant 24dB/oct. slope) 

Preamplifier: Audio Research Model LS3 
Amplifier: Aragon 4004
D/A converter, (outboard), Schiit Bifrost for disc and computer/online digital audio feeds...

Unfortunately, I currently must set-up system in VERY small room, roughly 10 ft. wide, by 11 ft. long, by 8 ft. high, parallel walls, with a roughly 30 inch x 30 inch doorway/"hall" into the room...(I know, not ideal...lol...)
Space limitations demand that the subs be placed in the room corners, with the stereo monitors in the same plane, as close as possible to them to maximize stereo spread, toed inward toward the listening chair, with two King size micro-fleece blankets hung on the wall approx. 30 inches behind the listening chair to eliminate early reflection from rear wall...

That stated, with the limitations as already expressed, how do I go about tuning my subs to the room as well as my monitors?...

I have a lap-top computer running Windows 8 O.S. with both USB 2 and USB 3 ports, as well as a 5 year old Radio Shack analogue RTA to use if downloadable software is recommended, and willing to purchase an accurate microphone/necessary equipment.

Any and all suggestions/recommendations very much appreciated.

So, step by step, how do I go about adjusting the SVS subs setting initially to get at least reasonably/moderately close to an ideal room response, (my small, almost cubicle room notwithstanding)?

What settings are suggested, (Subwoofer amp. gain, room size compensation, the 2 parametric equalizer setting, phase settings, etc.,)??? Bearing in mind that I am using the Marchand Electronics x-over at 60Hz.

Secondly, after preliminary setting adjustments are made, what procedures should I follow to "tweak" a better response out of my system, in my room...

Are there one or more recommended, user-friendly online/downloadable programs, (RTA/system/room analysis) that can assist me in my endeavor? 

Thank you for your patience and assistance in advance.

Sincerely,
T.A. Kogstrom


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## dougc (Dec 19, 2009)

An easy way to start would be to do the "crawl test" for sub placement. Place the sub at your listening position and crawl around the room. The place in the room that the sub sounds best is where it should go. Usually, but not always, it ends up being in a corner or at 1/4 points next to the walls. Use your spl meter to play test tones from your processor to each speaker individually so that each reads about 75db at your LP. Next step if you want to take it further would be to get a USB mic for measuring with REW and post some of the results on here. There is plenty to read up on in the REW help file to get your mind spinning and ready to take some measurements. The info recorded by REW can help you determine many things: placement, room treatments, EQ, etc. Have fun, share your results, ask lots of questions - and welcome to Home Theater Shack!


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## sdurani (Oct 28, 2010)

Synergist said:


> Space limitations demand that the subs be placed in the room corners...


Are those space limitations firm, or is there any chance of moving the subs to locations that could result in smoother bass? 

Also, is it possible to move your listening position so that it is around 1/3 of room length from the back wall?


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## Andre (Feb 15, 2010)

I have a PC 12 NSD and its perfectly happy in the corner of my room but if you want to experiment:


1. Do the sub crawl method to find the best place in the room for the sub. 
2. Take your measurements (RTA) and listen well.
3. Put the sub back in the corner, if the difference in sound is enough that you want to adjust, then its time to play.
4. using the RTA reading you took see how close you can match it by playing with the crossover point and all the lovely things your subs amp can do (just looked at the owners manual of the 13 ultra, which does alot more then mine)


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