Axiom Home Page Forums General Discussion Technical Questions Building a sub box

Got a question for those versed in building speakers.

I've been building speakers since I was a kid. I've built many subwoofer enclosures (mostly for cars). Since I can't afford to buy a new sub anytime soon I was thinkin about RE-buidling my current HT subwoofer enclosure. It's pretty ghetto right now but thats mostly because I had hoped to buy something to replace it by now. Well its going to have to last a bit longer but in the meantime I want to get the most out of it as I can.

I have two average quality 10 inch Pioneer car subs in my HT right now, but I was thinkin about taking my two 10 inch Kicker Solo-Baric subs out of my car and using them instead (moving the Pioneer's to the car) because they far better drivers.

Now my questions comes from this... The Solo-Baric's manual is very clear about not using a vented or large box for them. Now in a car the cabin gain allows for this, but in a big HT room I need a bigger enclosure and I'd like to go vented to pick the lower region's response up. I thought I learned years ago that speakers really weren't only good in say, a sealed enclorure, or only a vented one. I just don't want to risk ruining these speakers if I put them in a large vented box.

What do you all think?

I have built a few boxes myself for both home and car. I don't think you are going to hurt the speaker by putting it in a large box and venting it, you just won't be getting the best bass that that particular speaker can put out. If the manufacterer states that it should be in a sealed box then you probably will have better results in a sealed enclosure.

I don't know about using car sub's in a home theater setup though. I once built a vented enclosure that I used in my car and it was probably the loudest cleanest sub I had heard in an auto, but I tried hooking it up in a living room and the results were way less than dramatic. Anyway just some thoughts. . .

Well, *generalizing* you design enclosures off of need and the driver's Theile/Small Paramters don't you? At least thats how I'm looking at it here.

Its jsut the manual for these Kickers warns of damage to the driver if not used in a small sealed box. That's where I'm confused (concerned).

There are two possibilities :

1 The power rating for the driver assumes that cone movement is partially limited by the air in the sealed enclosure; you can use them fine without a sealed box but be careful with the power.

2. The surround design is something wacky with almost no "spring" effect (ie the cone will flop in and out as you turn the speaker over) and can only be used in a sealed enclosure.

I kinda doubt it's #2 but you could probably tell by turning the loose speaker over a few times

I would ask your question on the Parts Express message board. I built a sub and got a lot of good advice from those guys.

It is very important to follow the recomendations of the driver manufactures. If the specs says sealed box, and you use a vented box, there will not be enough of an air spring behind the driver, the driver will bottom out and get damaged very easily, to avoid this you will have to keep the volume very low.

It is possible to get very good performance out of a sealed box. I built mine using a Parts Express 15" Quatro driver ~$90, and the 250w PE plate amp in a sealed box about 3 cubic feet. It sounds damn good. Almost as good as my Outlaw Audio LFM-1

http://www.pesupport.com/cgi-bin/config.pl?#213392

hmmm, I've had a lot of ppl comment on how vented boxes cause the speaker to move more...

Try this on your vented sub:

First find something with a fairly constant bass track to play. Look at the movement of your sub (ie get an idea of how much its moving). Now take a sock or something similar and stuff the port so no air can get thru (freely). Now go take a look at the movement of the speaker again. If you take the sock out while its playing you should definitely see a difference. What kind of difference you ask? Well you might be surprised.

Inane, Go here and download WinISD. You can design Closed, Vented and Bandpass boxes with this program, and has the specs for both subs you mention. It calculates the responce & performance as you change box volume, port size, etc. Pretty cool program.

Let us know how you make out.

Shawn

hehe thats the program I already use

But my subs aren't in there... however I got the T/S for them and entered em manually.

a friend of mine owns a mobile electronics store and i think he uses sealed boxes for the solobarics,ill ask him tomorrow,he has 2-8 inch in his nissan p/u and they are powerhouses,those speakers deliver the most incredible slam for thier size.im sure they will give your ht a kick in the ass if set up properly

I wish I had that program 20 years ago when I was in high school. Using the Fs, Qts, & Vas, I did all the calculations manually. If I look hard enough at my parents, I'm sure the formulas are still tucked away in a box somewhere!

I grew up in a small town (35 to 40 thousand people) and back then, in that town, I was the king of car audio. People started to call me Mr. Bass. (It's amazing what a little knowledge will do) And it wasn't just a thumper, either - 5 amps and 12 speakers. And you couldn't see any of it in the cabin. Too bad I went through 3 alternators. Of course, the kids today wouldn't be overly impressed at that system, but 20 years ago it was sweet.