$190 (or less) Powered - Adjustable Bass Shaker


Update at bottom.

 * The Problem: House built on slab. Unlike wood sub-floors, concrete slab won't conduct bass well. Loveseat was not shaking as much as desired. Also, love seat situated midway in room ,not backed against wall (better if against wall, where bass is stronger).

* The experiment: I moved my 15" front firing Velo sub from the front corner of my listening room, to where I could point it directly at the loveseat we use to watch movies. I played parts of ST Insurrection that contained low end bass and it JUST ABOUT EJECTED ME ONTO THE FLOOR!

I then turned the sub down to 1/4 volume and turned the adjustable crossover down to 80hz. This worked great with incredible deep shaking, but the bass was lacking elsewhere in the room. I then knew to put my Velo back into its original place, and a bass shaker transducer was in order.

At $200-$300 for a mid-range bass shaker transducer (plus more for an amp to drive the transducer, and even more for an active network to control the frequencies) I searched for an alternative. Since my 15" Velo was an overkill with this particular usage, I came to the conclusion that a second - smaller sub, pointed directly into the loveseat would do the job and for much less.

It wouldn't take much of a powered sub to accomplish the task. I went to Best Buy and found two that I hoped would do the trick. A $149 Infinity 8" 75w and a KLH 10" 100w for $189; both front firing.

The choice was simple, the KLH was in stock, the Infinity was not.

What I got was a Sub with 100w amp, an adjustable crossover, auto power on, phase reversal switch, and a level control; All for $189. It worked greater than expected. Awesome deep shaking with an out-of-the-box plug-n-play device.

No doubt, you can't beat physical cone size of a driver; now I'm not so certain the 8" Infinity with 75w amp would of done as well.

Front of sub pointed towards and touching loveseat.

Optimum placement would be in the back , pointed in the middle; but no attempts were made to talk the wife into moving the table located along the back of the loveseat. Ya' know, after these tables were pictured in "those" magazines, we (she) just had to have one!

 After some experimentation, I finalized on these settings;

* 60hz crossover setting (you do not want to hear this second sub, just feel it)

* Phase inverted

* Level at 65 %

 The crossover is also set low because I didn't want the second sub to compete with my 15" Velo. Instead I wanted it to bolster the "feel" frequencies only. The phase reversal sounded a little better too.

Also, the sub needed to practically "touch" the loveseat for best performance. This allowed for maximum conduction from the sub to the couch. I'm tempted to make a foam rubber collar (and somehow paint or encase it in something black) to seal where the two meet, but it is working so well now, I'm going to let well-enough alone.

Now, I wish I had found a used sub for sale, instead of buying a new one. I'm sure there are many used smaller powered subs for sale by those who upgraded to larger ones; that would practically give them away.

If you try this, I suggest a front firing sub. Bottom firing will flood the entire room and possibly interfere with your main sub; when all you want is to tickle your (you know what).

Good luck on your setup.

UPDATE: I purchased some close-out Aura bass-shaker-transducers fpr $8.95 each and installed two of them in the same loveseat; and powered them with the amp in my shaker powered sub. There was a noticeable improvement using the transducers over the second sub pressed up against the couch. Sadly I had to wait until the Aura's were selling dirt cheap to experience them. Still, my original suggestion works fine if you have a additional powered sub sitting around collecting dust.

Click HERE to view my Aura installation page.



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