Help with choosing sub-woofers please

[clear thinker]   You and others advocate the crawl test as if all standing waves are bouncing around along the ground.  Surely they are present throughout the room, in which case we should also test whilst standing?  Would save my knees as well.

Your absolutely correct. Crawl Test is a misleading term / title used to search the net for directions and examples. My subwoofer manufacturer suggests the test near the beginning of the setup procedure. 

In my limited experience I usually elevate one subwoofer onto a sturdy table or side table at the listening position. Using the sofa or chair should be fine. While playing my subwoofers included Sweep Tone CD simultaneously through the main speakers and the subwoofer I walk the room listening and making note of the rooms nulls and modes. I measure the modes slightly varied levels using a Radio Shack SPL meter. I found actually crawling the room will yield slightly varying intensities and locations that I consider overkill.

As a result my two twelve inch subwoofers are asymmetrically located in the rooms two loudest modes. They're mounted on MDF platforms with 2 inches of high density foam using extra soft rubber casters rolling on a suspended wood floor.

Since every aspect of every room and system is unique, like speaker placement the Crawl Test is simply a starting point that I've found indispensable for any new installation. Best of luck with your project.

Good luck to you! I'm hoping you'll post again with your results:-)

I had been using a single 15" woofer for about 45 years, either sum L+R or just use R.  Neither are correct as each channel should have a woofer or more. The electronic filter for low pass was 36Hz at 18db per octave.  Full signal went to the Quad ESL 63.

Recently I replaced the single woofer with two JL Audio E112 subs.  The important points here are there is a woofer for channel, the sub has a built in low pass filter currently set at 50Hz, and the signal to the main speakers has a passive high pass single order filter, 3 db down at 80 Hz.  Perhaps other crossover frequencies would be better but that is what I have.  I tried the high pass filter in the E112s, the flexibility would have been nice, but the ESLs are not forgiving to E112 electronics.

You will likely need test gear to setup subs. When I am close I listen to a string bass recording to adjust and confirm.  I use Room Equalizer Wizard software and a MiniDSP UMIK-2 microphone.

Use yer earballs for setup...a test CD (I use one of the Stereophile CDs) helps but really that's all the technocrap needed unless, well...you can't hear. Also, listening to music is always a good idea. I have 3 RELs bought used over the years and they're great...two for hifi and one for video (different rooms). 200 bucks of so each. One monster Mackie in my music studio also...that one goes down to 19hz and weighs a ton (Mackie HRS 120, no longer made but a way cool 92 lb. beauty). Subs add reality to the show as life (remember that?) is full of natural lowness (frequencies, not "low lifes" although those exist also...my uncle Phil was one...man...) which is why your main speakers will sound happier with subs. 

 ((((( @audioconnection    What is it about the design of the Vandersteens that allow them to behave so differently as a stereo pair with essentially the same control systems?))))

Its real simple every room is different and the Vandersteen Sub 3s adapt first by not having to play around with DSP processing that also spoils mid range. The Sub 3s feature their 11 analog adjustable pots for the left Channel and 11 for the Right channel achieving a far better in room response then other designs allowing the whole system to perform well in any room at its best!

JohnnyR

Vandersteen Dealer NJ