Need help with port length / size based on my enclosure

TX1978 said:

To clarify I know that the color changes when its "on" but mine is green all the time, and then changes to yellow under heavy bass. It still plays bass before this, but the light is green.

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That's just showing you strain on the amp. Green/yellow/orange is ok. Red means your clipping the amp. As long as you don't see red your fine.

Ok, thats good to know.
If I play music, it is LOUD and sounds good. If I play the THX intro, even at lower volumes, the sub clicks and pops like no tomorrow. There is almost no bass, and then click/pop. Its frightening.
Am I bottoming the woofer out, even at low volume?

I think it was the sub bottoming out. At lower volumes, less than 35 out of 70, its ok (sub amp is at 1 o clock). However, there is almost no bass output during the thx intro now. Movies are fine, but that intro has minimal bass when it used to have tons on my old sub. Strange.

My wife says the house is falling apart.

TX1978 said:

I think it was the sub bottoming out. At lower volumes, less than 35 out of 70, its ok (sub amp is at 1 o clock). However, there is almost no bass output during the thx intro now. Movies are fine, but that intro has minimal bass when it used to have tons on my old sub. Strange. My wife says the house is falling apart.

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Could be ULF your feeling. Maybe your sub is attempting to produce high levels of less then 20 hz causing strain to the woofer? These are the frequencies you feel More then you hear. How does the woofer look before it pops? I don't know much about mechanics of a woofer, so I don't have much to tell you.

If you take a video we could all see what your talking about. The THX demo has quite a bit of ULF content. Do you have a Hpass on your subwoofer?

I have the ps3 connected to the receiver via hdmi, receiver running/handling EQ, sub out of the receiver plugged into the SPA500, spa500 connected to woofer.

You want a video of it popping? I took a video of it at lower volume when it doesnt pop, and the woofer excursion has to be close to max. At double this volume i'm sure it was bottoming out.
Still odd that the bass lacks during the intro.

How to post a vid? Where can I host it?

The lack of bass is not bc it is ULF. I would feel that or hear it vibrating the walls.

Also, I am using the LFE input in the spa500, which bypasses the amps eq/filters.

I'm sorry if I missed it, but have you setup a High Pass filter?

No stand alone high-pass filter. Just what the receiver's processing sends to LFE output.

I have a video of the popping & cracking but dont know how to put it up on here.

No low pass on Sub- all the way up.
Receiver takes care of crossover.

Do you understand?

Yes I do.
Did you see the video and the popping at the end?

Says video is removed or deleted. SO I cant see it. I havent a clue what your Hpass is set at from your AVR. BUT without having a Hpass where it needs to be you could easily damage the driver when listening to the THX scene if at reference or close to it volume.

There is quite a bit of movement pass Xmax for protection but that goes quick below the port tune.

I certainly didnt remove the vid, so i'm not sure what happened? I will try again;
<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid35.photobucket.com%2Falbums%2Fd188%2Fgregseman%2Ftheater%2F693294A5-6D12-4391-85F1-A2A9D3D4AF66_zps960ljyqi.mp4">

http://s35.photobucket.com/user/gre...2-4391-85F1-A2A9D3D4AF66_zps960ljyqi.mp4.html

http://s35.photobucket.com/user/gre...2-4391-85F1-A2A9D3D4AF66_zps960ljyqi.mp4.html

That pop/clank at the end sounds bad, like it's slamming the backplate, but I THOUGHT I heard the sub making noises BEFORE that.
What is the actual net volume of the cabinet after all bracing/driver, and the dimensions of that port(in INCHES PLEASE!), and the Driver(I think you said Dayton 18" ?)I want to model this in Winisd.
Sounds like you are bottoming out that driver, the info I've gathered is the SPA500 has either a 2nd or 3rd order HPF of 18hz ( from here and the 'Webz).
The SPA500 manual says the LFE input bypasses the Low Pass on the amp- which is good, but it doesn't say it bypasses the Eq.

Thanks

Total internal volume is 9.8x cu ft. Less driver, amp, bracing and port its 8.8x cu ft.

Sorry, in inches it is 15206 in^3 after the driver, amp, port, and bracing.

Also, it is a dayton 15". Rss390hf-4.