# Box Stuffing Demo



## TOOSTUBBORN2FAIL (Jan 31, 2011)

Well, this was supposed to be a full write up, but 4 tests will have to suffice. Sorry Seafish, I'll have to redo the whole thing later. One of the hurricane nuts backed out, and I'm going to have to tear apart the box to get it out.


So these are measurements of a completely empty box, a box with natural sheep skin wool, one inch thick ocf, and two inch thick egg crate ocf. The test box is about 0.99 cubic feet before driver displacement. The driver is a HAT L6SE. Nominal output was 114db at 0.125 meters. Bandwidth of test is 31.5hz-5000hz. I chose this as its really already past where a 7" midbass/midrange should be used on both ends. 

Frequency Response

I've included them all together as well as separate. 


This is the empty box frequency response.

This is the sheepskin wool frequency response.

This is the 1 inch ocf frequency response.

This is the 2 inch egg crate frequency response.



Distortion plots are in the same order as above, I put them all together to make them easier to compare. Had testing gone smooth, I would have ended with a second empty box measurement just for consistency, but it didn't turn out. Notice the large uptick in 3rd order distortion around 188hz that almost hits 1% on each treated measurement. Also notice the reduction in distortion at 348hz and 700hz on each treated measurement. This corresponds with modes you'll notice in the waterfall plots.






Waterfall plots. Again, all together to make it easier to compare. Pay attention to 348hz and 700hz.


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## Jscoyne2 (Oct 29, 2014)

TOOSTUBBORN2FAIL said:


> Well, this was supposed to be a full write up, but 4 tests will have to suffice. Sorry Seafish, I'll have to redo the whole thing later. One of the hurricane nuts backed out, and I'm going to have to tear apart the box to get it out.
> 
> 
> So these are measurements of a completely empty box, a box with natural sheep skin wool, one inch thick ocf, and two inch thick egg crate ocf. The test box is about 0.99 cubic feet before driver displacement. The driver is a HAT L6SE. Nominal output was 114db at 0.125 meters. Bandwidth of test is 31.5hz-5000hz. I chose this as its really already past where a 7" midbass/midrange should be used on both ends.
> ...


Cool. So..in laymans terms. What are the results?


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## rton20s (Feb 14, 2011)

Sorry to hear about the hurricane nut backing out and ending the testing. Not having had a lot of time to anazlyze the charts, it looks like there may be some tradeoffs? Perhaps a slight smoothing in frequency response (most apparent with sheepskin wool), but you get some increased 3rd Order distortion at some frequencies? Waterfall plots certainly look better across the board.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Well, from these measurements it shows the box/driver ringing at 348hz and 700hz, the treatments eliminated that. 

It did show and increase in 3rd harmonic distortion around 188hz, but a reduction in 2nd order distortion around 200hz, which is bad.

That said, your talking about in all cases less than 1% distortion. I'll be dead honest, I couldn't _hear_ a difference while measuring.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Rton20s beat me too it. Pretty much exactly what he said. I just notices I forgot the pictures of the actual treatments, I'll get them up tonight or tomorrow.


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## rton20s (Feb 14, 2011)

TOOSTUBBORN2FAIL said:


> Rton20s beat me too it. Pretty much exactly what he said. I just notices I forgot the pictures of the actual treatments, I'll get them up tonight or tomorrow.


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## seafish (Aug 1, 2012)

TSTF, nice work…sorry about the problems. 

I still REALLY think that the thicker 4" rockwool pad is going to help the most….though whether the diff is audible will be the real question.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Yeah, that's my thoughts too. That said, there is a clear difference in performance between nothing and something and a clear difference between the 1" and 2" foam. 

I'm also going to try using more than one product after the individual products are done. For instance all the rock wool pads at once.


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## seafish (Aug 1, 2012)

TOOSTUBBORN2FAIL said:


> Y
> 
> I'm also going to try using more than one product after the individual products are done. For instance all the rock wool pads at once.


THIS!!!…different layers of different materials!!

Like the sheepskin OVER the rockwool over some cork…does NOT need to placed directly behind the speaker, but simply inside the enclosure to the sides of the speaker…should leave room for more thickness!!!


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