Tempest done... airspeed and test track questions (1 Viewer)

[Owen Bartley]

I'm FINALLY done my Tempest! All I can say is great guggamigga the thing is big. I'll have pics of the construction and stuff up soon, hopefully after the weekend. But for now I'm just breaking it in and playing around tweaking. Once I set the phase a little better and played around with the gain, the levels from the receiver, and the tone controls, it started to blend in really well and sound great!!

Now I'm just working on a few post-construction, pre-finishing things. First off, I'm looking for some more test tracks. I've used LOTR (the typical chapters), Blade II (the whole movie), and the helicopter explosion from Matrix (sounded awesome!)... I'll give SW:Ep II a try this weekend, and I was thinking about renting Titan AE and Maybe U-571 (or 751?) because I've heard they have some pretty goos bass scenes. Anyone else have a reccommendation?

Second, I'm noticing that not a lot of air is coming out of my port. It's a 5.5 inch sonotube, and I'm fairly sure my box is sealed pretty well, so I'm just wondering what kind of movement I should be getting. I think in my LspCad sim it showed around 15m/s, but I'd have to double check when I get home tonight. Do any of you guys with larger ports have a lot of air flow?

Thanks!

-one satisfied Tempest owner

 

[Jeremy Stockwell]

Hey Owen, I just finished my Tempest not too long ago (January 2, 2003), and I'm having a blast with it (sometimes, literally!)

SVS has lots of sub-demo material here.

About air from your port -- what's your tuning point? How big is your enclosure. Mine is 17.5Hz/290L and I generally only get some chuffing from the port (6" PVC) with very loud bass that is below my tuning point. I notice it most when testing sine waves for measurement and calibration (and sometimes, just for fun :b). On movies, there's usually enough other noise going on that I don't notice it.

JKS

 

[Seth_L]

You can buy Titan A.E. in a 2 pack with the "new" Planet of the Apes at Best Buy for $17. I picked it up yesterday. The DTS track on the Titan A.E. DVD will destroy a sub if you're not careful.

Seth

 

[Isaac C]

We Were Soldiers is another subwoofer demo DVD

 

[Owen Bartley]

I generally only get some chuffing from the port (6" PVC) with very loud bass that is below my tuning point.

Actually it wasn't chuffing that I was worried about, but a lack of air movement. I've been putting my hand up to the port (crawling around on the floor like a dumbass) to feel how much air its moving and to feel the driver to see how much excursion I'm getting (don't want to max it out) and it just seems like not much. I don't know, I don't have a lot to reference, I've never seen a port that wide before so maybe its normal.

So Titan AE is on my list to get for the weekend for sure.

Thanks guys!

P.S. Jeremy, I put on test tones for fun as well and run into the adjacent bathroom to feel the wall flex. lol :b

 

[Jeremy Stockwell]

Owen,

Sorry I guess I didn't read your first post well enough. But still, my question is what's your enclosure tuned to? You won't get much air out of the port until you get below your tuning point.

Like I said, I do get lots of air moving out of my 6" port once I get below my tuning point.

JKS

 

[Owen Bartley]

Sorry, I left that out... my box is 210L internal before driver and bracing and port, I think it should be around 190 or 200 net. It's tuned to 19Hz. I wanted a bump a little higher in freq. since its mostly for HT.

I'm going to put it out in the middle of the room this weekend, plug the port, and do the kleenex test around all seams. Also, I'll double seal the amp and driver with another layer of closed cell tape when I put it together permanently after I finish (paint and trim) the sub.

 

[Owen Bartley]

Holy crap... my brother had some demo tracks in mind to test the sub tonight, including the T Rex in JP, the crash in Castaway, and then one that absolutely blew me away. The end of Fight Club where the buildings blow up is insane! When the first one hit it scared the crap out of me. That's my new favourite demo scene. Wow.

 

[Troy_j]

General comment: If it sounds like you want it too, be happy. And don't worry about the small shi-stuff.

 

[Allen Ross]

well i "scored" a copy of LOTR Two Towers, 4 800 mb files, in svcd, and i just have to say gooooooooddddd dammmmmmmnittttt, that is freaking insane, this was the first real test that i gave my sub, and i am still blown away, the entire movie is filled with 15-50hz notes, i never had my tempest perform like that before, when that huge dragon flaped its wings, i nearly shit my pants, the excurtion was insane. When the explosion on the front gates i was litterly blown backward. also when evert the trees took a step, the entire dorm shock. needless to say i was freakn amazed. I littrly cried when i heard/felt that bass, that 450 it cost me was well worth it.

 

[Jeremy Stockwell]

Owen,

How'd your tests go? Are you still not getting any/much air moving from your port, even when you're playing movies or test tones that have loud content well below your 19Hz tuning point?

Is it possible that your tuning point is actually lower than you think? What length of the 5.5" sonotube did you use?

It sounds like you're pretty happy from your comments about Fight Club, etc. so if it ain't broke . . .

JKS

 

[Owen Bartley]

Jeremy, I think you're right. When those buildings blew in Fight club I got some good air movement, and I ran through Titan AE this weekend as well, and I'm still smiling. That was a great demo/test DVD, I'll try to pick it up if I see it used/cheap. I forget the exacl length of the tube, I'll check when I get home tonight, I thought it was about 25" or so. I didn't get to do much air leak testing, but I will try to do it before I finish the sub.

On the bright side, I did get around to whacking up some pics of the construction process. Take a look at http://www.geocities.com/needfiles1/ (go to the SUB page).

 

[Owen Bartley]

Updated my page (moved it off Geocities). Much faster, and actually avaialable!