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Other Stuff => Archived Manufacturer Circles => Herbie's Audio Lab => Topic started by: NachoTime on 26 May 2013, 06:23 am

Title: Big Fat Dots with subwoofer spikes
Post by: NachoTime on 26 May 2013, 06:23 am
I'm curious about the recommended way to employ Big Fat Dots with my subwoofer.  It's a very heavy (3/4" MDF, double-walled, sand filled) downward firing 12" servo sub.  These are the spikes I'm using:

(http://www.parts-express.com/images/products/large/240-715_l.jpg)

Should I just place the dots under the existing spikes/disks and call it good?  Unscrew the spike tips and place the chrome foot on on the dots?  Remove the spikes completely and go for wood on dots?

Thanks,
Sten
Title: Re: Big Fat Dots with subwoofer spikes
Post by: Herbie on 27 May 2013, 05:01 am
Hi, Sten. Because all three methods would employ the same dBNeutralizer material that Big Fat Dots are made of to accomplish the isolation and decoupling, all three should give roughly equivalent results. You could try whichever configuration you choose and most likely get satisfactory results that meet and exceed your expectations. As to whether one configuration works better than the others with your particular system and environment, you would have to audition each in order to determine that--not necessarily at once, but over time.

With most subwoofers on a bare floor, Four Big Fat Dots directly between the bottom of the cabinet and floor gives ideal results, no real need for spikes. (On a carpeted floor, you would use Giant Fat Gliders instead of Big Fat Dots.) Down-firing subs often require a minimum floor clearance, however, so using spikes can be helpful to achieve the necessary floor clearance.

Steve Herbelin
Herbie's Audio Lab
Title: Re: Big Fat Dots with subwoofer spikes
Post by: polyglot on 9 Aug 2013, 07:25 pm
With most subwoofers on a bare floor, Four Big Fat Dots directly between the bottom of the cabinet and floor gives ideal results, no real need for spikes. (On a carpeted floor, you would use Giant Fat Gliders instead of Big Fat Dots.) Down-firing subs often require a minimum floor clearance, however, so using spikes can be helpful to achieve the necessary floor clearance.

Steve Herbelin
Herbie's Audio Lab

Steve,

does the weight plays a role on the choice of footers like the Big Fat Dots? I am thinking for a REL Britannica II and a REL R205. Also, do you recommend to top load the subwoofer with e.g. DIY sandbags?

TIA!
Title: Re: Big Fat Dots with subwoofer spikes
Post by: Herbie on 9 Aug 2013, 08:59 pm
Weight of itself is usually not so much of an issue as is the nature of the vibrational environment that the Fat Dots are dealing with. Bigger and heavier subwoofers will typically generate a lot more mechanical vibrational energies than smaller subwoofers, so in this way yes, weight has a correlation. Big Fat Dots should do very well with both subwoofers mentioned in most environments. If you have severe macro-type vibration issues such as with a trampoline-like suspended floor, Giant Fat Dots will surely take care of any problems.

Adding some stabilizing weight on top with sandbags or granite slab is often beneficial, especially if you have a compliant decoupling interface underneath--they'll work hand-in-hand to achieve more of a whole-cabinet isolation.

Steve
Herbie's Audio Lab 
Title: Re: Big Fat Dots with subwoofer spikes
Post by: andycsb on 16 Feb 2016, 02:48 pm
Hi everyone. Need advice with smallish footprint tower speakers used in tandem with stock threaded spikes and possibly big fat dots.

Question...what do spikes do? Couple or decouple or? What would be the ideal situation? What if I remove the spikes and replace them with big fat dots? How about spikes on big fat dots? :)

Speakers are on 3/4 inch mdf platforms. Flooring is concrete.

Thanks for your help.

Title: Re: Big Fat Dots with subwoofer spikes
Post by: Herbie on 16 Feb 2016, 03:29 pm
Spikes couple and "drain" vibration from the cabinet; they also reverberate vibration right back up the spikes the way they came, causing glare, coloration and other distortion. Replacing the spikes with Big Fat Dots is more of an ideal situation; you'll get a better potential of the speakers, most likely a more linear and better-defined bass, and subtle improvements throughout the audio spectrum.

Spikes would punch right through Big Fat Dots, so if going with a spikes-to-Big Fat Dots solution, you would want to use a grounding base under each of the spikes instead: http://herbiesaudiolab.net/base.htm (http://herbiesaudiolab.net/base.htm)

Using four Little Fat Gliders or Giant Fat Gliders under each mdf platform would provide additional benefit and also allow for easier mobility of the speakers.

Steve
Herbie's Audio Lab
Title: Re: Big Fat Dots with subwoofer spikes
Post by: andycsb on 16 Feb 2016, 05:14 pm
Thanks Steve.

Let me understand this correctly...in essence....big fat dots will "drain" vibrations from the speakers (a good thing?) by absorption...while simultaneously absorbing any vibrations from the floor and mdf board that may make it's way back up the speaker. Kinda like a sponge soaking up vibrations from both sides. Or does it "block" vibrations? 
Title: Re: Big Fat Dots with subwoofer spikes
Post by: Herbie on 18 Feb 2016, 02:31 am
All of the above.

Steve
Herbie's Audio Lab