Build Your Own Multi Functional Theater Seat Riser

[gene]

<P><FONT face="Arial, Helvetica, sans-serif" size=2><A href="http://www.audioholics.com/productreviews/avhardware/SeatRiserp1.php"><IMG style="WIDTH: 125px; HEIGHT: 94px" alt=[IMGP2957001] hspace=10 src="http://www.audioholics.com/news/thumbs/IMGP2957001_th.jpg" align=left border=0></A>As a home theater enthusiast, there can be nothing more exciting than planning out your theater room.&nbsp; If you are contemplating building a riser for your theater room, I highly recommend you make it a dual purpose device such as I have done in this article.&nbsp; Auralex has provided an excellent blueprint which I neatly laid out the “how to” for in this MUST READ article.&nbsp; If you love bass like me, and want to bring a new level of enjoyment to your theater experience, then this is the type of theater seat riser you should be building.</FONT></P>
<P><FONT face=Arial size=2>[Read the DIY Article]</FONT></P>

 

[Sheep]

Wow, you made your riser much beefier then mine...

How much are those U boats? And do I need aurelex fiberglass or would just about and fiberglass work?

SheepStar

 

[Rob Babcock]

I wouldn't mind making a riser even though I only have one "row." It would be a good way to mount a tactile transducer without surgury on the floor.

 

[gene]

I am not sure about the price on the U-boats or mineral fiber. I am sure you can pop Auralex an email to inquire.

You can use fiberglass but this stuff is likely easier to work with and more effective for its purpose.

 

[Sheep]

I am not sure about the price on the U-boats or mineral fiber. I am sure you can pop Auralex an email to inquire.

You can use fiberglass but this stuff is likely easier to work with and more effective for its purpose.

See, my riser is portable. I can take it to whatever room I want. Did you put anything under your riser to hold the material in it, or is it permanent?

Also, would drilling the wholes in the side be necessary, or would the sound get in through the gaps? I though making holes tunes the riser to a certain frequency.

SheepStar

 

[ned]

Great Article Gene! I've the same question regarding stapling a liner on the bottom to prevent the fiber from escaping.

How about a stage, column , soffit for the nest project?

 

[gene]

Why is this thread so stretched verticle? Sheep your pics are huge!

I used a layer of plastic lining over the particle board on the floor before I layed the structure down. That combined with the carpet pad, carpet and molding, there is no chance stuff will leak out.

 

[WmAx]

You can find high density mineral fiber insulation boards at local commercial insulation contractors. The stuff is dirt cheap(at least where I live); about $35 USD for 6 pieces of 2" x 4' x 8', that is 8 lb/ft^3 density. I imagine that the Auralex 'branding' will add a considerable amount to the price tag.

-Chris

 

[JKL1960]

As my luck would have it I am just about to build a riser for my theater room (which is under construction and progressing nicely).

Mine is below grade (basement) as it will sit on a vapour barrier / felt pad on cement is it that necessary to decouple it from the floor with the u-boats? Is the fact that the u-boats create a space under the joists important? I get the impression that it is. I wonder if just drilling the holes between the joists would be beneficial (along with some insulation)? My riser will be approx 10" square.

Pretty timely article for me. Must be all the good karma I've been accumulating.

 

[Savant]

I have used blown-in insulation in riser construction. Messy and something of a pain. (Especially if the top of the riser has already been screwed on!) Aside from that, also quite effective.

As for tuning, the size of the holes do determine the "center frequency" of the riser, but since Gene's riser is floated on the U-Boats, there is some exchange of energy between the riser chambers due to the airspaces at the bottom of the joists. This changes the resonance effect, making the riser more wideband overall. There is still a limited bandwidth of effectiveness, but, relative to a riser with distinctly separated chambers, the riser as a whole has a lower Q with lower overall absorption. Small price to pay. I always prefer low-Q and lower relative α as opposed to high-Q and a higher relative α. I.e., I'd rather hit an octave or more with an LF device like this and sacrifice 25-50% of the absorption instead of having a device with extremely high absorption over a range of 5-10 Hz. Make sense?

 

[Sheep]

Why is this thread so stretched verticle? Sheep your pics are huge!

I used a layer of plastic lining over the particle board on the floor before I layed the structure down. That combined with the carpet pad, carpet and molding, there is no chance stuff will leak out.

Sorry, I uploaded that pic before I started scalling. By the way, it's horizontal

I sent Auralex an Email regarding pricing and dealers. All the ones I searched are for pro audio, and probably won't carry those products.

I'm going to see what I can get as far as local suppliers goes. If I can't get mineral wool I'll just nab some high density fiberglass insulation.

SheepStar

 

[ned]

go online. free shippping, tax free and less MSRP the local retailer,

 

[Scott R. Foster]

Jeff:

Have you ever experimented around with building a riser with chambers of varying volume - any benefit you can see given the extra complexity?

 

[WmAx]

http://www.sweetwater.com/store/detail/MFiber2/

Appears that the markup is about 300% for the Auralex branding, compared to my local prices, at least from above online retailer.

-Chris

 

[Sheep]

http://www.sweetwater.com/store/detail/MFiber2/

Appears that the markup is about 300% for the Auralex branding, compared to my local prices, at least from above online retailer.

-Chris

Wow, yea, not very good.

I need just a bit less then 7feet x 4feet x 7inches. I emailed a canadian company that has similar stuff. See what they say.

SheepStar

 

[RLA]

I am not sure about the price on the U-boats or mineral fiber. I am sure you can pop Auralex an email to inquire.

Gene,

I am not sure but I would think that a U-boat has some historical value and would be fairly pricey. Must have been a real pain to get those U-boats up the stairs, did ya have to take the machine guns off?

 

[Audioholics]

I was totally thinking the same thing the entire time I read the review...

 

[Scott R. Foster]

No!

You keep both the large and small deck guns for AA work and repelling boarders from the riser.

Just set in place and build around the u-boats:

http://www.msichicago.org/exhibit/U505/exhibit/a_restoration/index.html

 

[gene]

I am not sure but I would think that a U-boat has some historical value and would be fairly pricey. Must have been a real pain to get those U-boats up the stairs, did ya have to take the machine guns off?

That's about as funny as a screen door on a submarine LOL I should watch U-571 to really test out the effectiveness of these U-boats

 

[Savant]

Jeff:

Have you ever experimented around with building a riser with chambers of varying volume - any benefit you can see given the extra complexity?

"Experimented" is probably not what I would call it. But, yes, I have explored this. The math involved is run-of-the-mill Helmholtz equation stuff, Scott. You can toy with it yourself to ascertain whether the complexity is worth the effort. The physics here tends to play out in reality quite well, so - in general - WYSIWYG when you run the calcs.

That help?

Edit: I would add that you can often utilize a common joist cavity size and vary the port size to get the desired effect. The only practical limit is how big/how many holes in the joist faces before you worry about structural failure.