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I was considering an Tempest X2 build, but now I am interested in a Shiva X Dual PR build. I am not sure this will work for me though and hopefully someone can confirm for me.

I will be building the same box that is in the Shiva notes. The question I have is that this box will be sitting inside an Entertainment Center where the dual PR's will not really have any open space on the outside of the box on each side. Is this a problem? If this setup needs space to "breath" on the left or right side of the box where the PR's are then how much space do they need?

Also just to confirm with this setup the dual PR's do not need to flex outside of the box and just flex into the box.

With the X2 option I was going to put the port on the front, but I am worried about that build because the depth of the box is not great.

Thanks in advance!

PS if it matters I am looking to power this with Dayton HPSA500 Plate
 

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Think of passive radiators as big ports. They only move at the lowest frequencies, and so with the highest amplitudes. They need as much free space as the driven radiator. Your design sounds like a problem.

That said, I find a single sealed Tempest X fills my space nicely with 500W. How much space are you filling?

Frank
 

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Yea that is what I was afraid of. I could probably cut into each side of the entertainment system, but that would really just be more like building an enclosed box (about same size of main box) on each side of the main box. If that makes any sense. :foottap:

Sounds like I am back to the ported box. This is what I am considering for the ported box

Tempest X2 15" Subwoofer
oAudio - 500W Amp
Box 24" Wide, 20" Deep, 30" Tall resulting in 8.33 Cubic Feet
Vent 6" x 27"
WinISD is telling me 17 Hz Tuning

Since this is being built into an entertainment system it will need the port on the front and since the box will only be 20 inches deep I will need to put some type of angle on the port so that it runs back and then up or down. Does anyone think this port will be a problem?

On the tuning of 17 Hz I think I like this since I want some low bass, but since this will be part of the main house TV setup I don't want to over due it for everyday TV watching. Correct me if I am wrong, but 17Hz should still give me plenty of bang for the HT type movies. The family room is probably 20x20 and then the dinning room and kitchen open to the back to walls which are about the same size again. Lots of open space.

I do have more space to build out a bigger box, but naturally I start to hit trade offs many of which butt up against the wife factor.

Let me know what you think
 

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Kevin posted an EZ Slot port build using the Tempest X2 which would be a good option if you need to go ported. About 5^ft or so.

OAudio amp with a ported design is a no go I'm thinking. The HPF's also come with a certain amount of boost which won't make your driver happy at higher listening levels due to over excursion. From reading this and other forums, the OAudio is more suited to smaller sealed designs.

With that said, I'm using one in my Tempest build (sealed) against Kevin's suggestion. In my case, the OAudio was the most cost effective solution due to the high shipping charges to get stuff over here. My listening levels are low (well below reference) so I'm thinking it should work out ok.

Of course, I'm a relative noob to all of this and just getting ready to do my first build in a LOOONG time so I am just passing on the advice I've received....
 

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I've an Oaudio plate amp on a Tempest X sealed and it's an ideal combination.

The issue with the Oaudio amp in tuned applications is that there's quite a bit of sub-20 Hz boost in the lowest subsonic filter settings, right where the port is rolling off and the driver's excursion is maximized. In a sealed application, it's not an issue due to the low-end roll-off inherent in a small sealed box.

Frank
 

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The OAudio is going to limit your headroom down low in any build. It has boost, which requires power, and when you hit the limits the amp will clip and make a nasty noise.

I don't even recommend it for the sealed builds, because of the boost/clipping. If it were >1000W, I'd have fewer reservations about recommending it because the boost isn't necessarily bad if you have the power on tap to use it.

So... I repeat. I DO NOT RECOMMEND THE OAudio Amp. If you get poor results with it, you have been fairly warned.

Kevin Haskins
Exodus Audio
 

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Yea that is what I was afraid of. I could probably cut into each side of the entertainment system, but that would really just be more like building an enclosed box (about same size of main box) on each side of the main box. If that makes any sense. :foottap:

Sounds like I am back to the ported box. This is what I am considering for the ported box

Tempest X2 15" Subwoofer
oAudio - 500W Amp
Box 24" Wide, 20" Deep, 30" Tall resulting in 8.33 Cubic Feet
Vent 6" x 27"
WinISD is telling me 17 Hz Tuning

Since this is being built into an entertainment system it will need the port on the front and since the box will only be 20 inches deep I will need to put some type of angle on the port so that it runs back and then up or down. Does anyone think this port will be a problem?

On the tuning of 17 Hz I think I like this since I want some low bass, but since this will be part of the main house TV setup I don't want to over due it for everyday TV watching. Correct me if I am wrong, but 17Hz should still give me plenty of bang for the HT type movies. The family room is probably 20x20 and then the dinning room and kitchen open to the back to walls which are about the same size again. Lots of open space.

I do have more space to build out a bigger box, but naturally I start to hit trade offs many of which butt up against the wife factor.

Let me know what you think
You safely have 6.5-7 cubic feet. You can build a ported Tempest-X2, and use the suggested 500W plate amp and be done. You have to deal with the extra complications of designing the port. You are balancing port area vs. length/size of the enclosure. You are going to need to design a slot-port, because there isn't an off-the-shelf port long enough in that size enclosure. If you do a slot with about 30 in^2 in area, you should aim to have it be about 25" long for roughly a 19-20Hz tune in a 6.5 cubic foot box. That assumes 50% fill (roughly 60oz. of polyfill).

For everyday TV watching, any of these solutions are gross overkill. I'd say just build a sealed box design and make your wife happy and keep things simple. You can spend an extra $50 on a EP-2500 type amp, and step up to the Maelstrom-18" if you are concerned about output.

Kevin Haskins
Exodus Audio
 
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