IB guys?

[Chris Roemer]

So my buddy has an HT going into his basement.
He's got a stud wall built 2' out from his basement wall. He'd like a sub "in the wall" so he's got no "box" in the room. I'm thinkin' IB?

He'll have around 200 cf behind the wall (2x14x7). When I model the Dayton IB15 it looks like it'll do around 23 hz with a .67 Q. Looks good to me. Also, when reading the specs, it SEEMS like 100w RMS will push it to its excursion limits, so . . . would the 100w plate amp (70-80 @ 8 ohms) be sufficient to push this with, or would the 240w (170 @ 8) be better, or does this 15" IB driver really want more power (350w RMS thermal limit)?

Thanks

[thomasw]

Provided Link: IB sub FAQ pages (http://home.comcast.net/~infinitelybaffled/)


"does this 15" IB driver really want more power (350w RMS thermal limit)?"

When it was first offered Darren said no more than 140 watts/driver.

Your friend is going to need more than one driver. Might checkout the IB FAQ in the link below

[Pete Schumacher ®]

> So my buddy has an HT going into his
> basement.
> He's got a stud wall built 2' out from his
> basement wall. He'd like a sub "in the
> wall" so he's got no "box" in
> the room. I'm thinkin' IB?

> He'll have around 200 cf behind the wall
> (2x14x7). When I model the Dayton IB15 it
> looks like it'll do around 23 hz with a .67
> Q. Looks good to me. Also, when reading the
> specs, it SEEMS like 100w RMS will push it
> to its excursion limits, so . . . would the
> 100w plate amp (70-80 @ 8 ohms) be
> sufficient to push this with, or would the
> 240w (170 @ 8) be better, or does this
> 15" IB driver really want more power
> (350w RMS thermal limit)?

> Thanks

You'll need a manifold if you don't want the wall shaking apart. And you'll want LOTS of drivers if you desire HT levels of sub 30Hz content. You may also consider getting the RSS390HF. You'll get lower distortion than with the IB15.

[Chris Roemer]

> You'll need a manifold if you don't want the
> wall shaking apart. And you'll want LOTS of
> drivers if you desire HT levels of sub 30Hz
> content. You may also consider getting the
> RSS390HF. You'll get lower distortion than
> with the IB15.

I DO understand the "shaking" aspect, but (since this stud wall is only 2' in front of poured concrete) what if the backside of the wall was braced straight back to the foundation wall with, say, 2x4's or 2x6's (one off each "corner" of the driver - so 4 braces) running right back 2' and bonded to the concrete wall with construction adhesive, like "PL1"?

Just asking.

[curt_c]

> I DO understand the "shaking"
> aspect, but (since this stud wall is only 2'
> in front of poured concrete) what if the
> backside of the wall was braced straight
> back to the foundation wall with, say, 2x4's
> or 2x6's (one off each "corner" of
> the driver - so 4 braces) running right back
> 2' and bonded to the concrete wall with
> construction adhesive, like "PL1"?

The sub will be stable, but the rest of the wall will be flexing like a big ol' drumhead. You need to construct a sub-enclosure (hey! it's a pun, get it?) isolated from the wall to constrain the back wave from the driver. This also opens your sub search to just about any driver. Not just the high Q ones...

C

[Pete Schumacher ®]

> I DO understand the "shaking"
> aspect, but (since this stud wall is only 2'
> in front of poured concrete) what if the
> backside of the wall was braced straight
> back to the foundation wall with, say, 2x4's
> or 2x6's (one off each "corner" of
> the driver - so 4 braces) running right back
> 2' and bonded to the concrete wall with
> construction adhesive, like "PL1"?

> Just asking.

Even with the extra bracing, you'll be directly exciting the wall at the worst possible place. I'd go with even eight 2x4 all around the driver flange. And the more drivers you add, the worse it will get. The beauty of the manifold is the near total cancellation of inertia induced vibration of the moving masses. I suppose you could give it a try, making a manifold later on if needed.