Sealed 1503 for newbie

[PoorboyMike]

Hi all.

I just purchased a used BP1503 and plan on building a downfiring sealed enclosure that looks like a nice end table. Size isn't really an issue, but it would be nice if I didn't need a fork truck to move it. 8O

My current living room is 12X20 with one end opening up into the kitchen the entire 12'. I will use this about 60/40 HT to music and it will be replacing an Athena AS-P400 10" sub. I would like good slam for HT of course, and have considered going ported, but I think the whole family would kill me if had something that put out 120 db. I think it would be too tempting for me. :W
So, I thought a large sealed box would be a good compromise and still handily spank the Athena. I don't have an amp yet but I'm considering the Behringer EP1500 running bridged and of course a BFD. Would the claimed 1400 watts be too much? I thought this amp would be a good choice because once we get our addition put on, I plan on doing an IB.

I downloaded Unibox but it confuses me somewhat. Could some of you fine people give me some recomondations for a sealed cab? The amount and type of fill I should use would be helpfull too, because I'm not to sure I understand that yet. Any help would be greatly appreciated.

Thanks!

[ThomasW]

The 1503 has a fairly high Fs 26.8Hz, so it would take a pretty big box to get a low tuning.

Reasonable options are small sealed box with an LT circuit, or a 2' cube with PRs tuned to 18Hz.

If you go ported just copy the design in this link and use a forklift

http://home.comcast.net/~klone-audio/page30AS-15-1.html

[KeithM]

I suggest using WinISD. It's a lot easier to use and I say it's better than unibox. For a low tuning, it sounds like you'd be looking at a linkwitz transform circuit. You'd still be better off with porting with an Fs that high. Also, 1400 watts can be used, but you would rarely use that kind of power unless you sit 100 feet away from your sub.

[PoorboyMike]

Yeah, 1400 watts seems like overkill but if I use a pro amp, the single 4 ohm voice coil doesn't leave me many options. The guy I'm getting it from (Florida Chuck) says I'd be quite happy with the Oaudio 500w Bash amp with a little boost on the low end. Unibox says I should still get over 100db at 20hz (without boost) in a .5 Q sealed box (90l is what unibox says; this seems small) and I'm hoping room gain would fill in the rest nicely, but I wouldn't have any way to compensate for room modes.

I don't mind going ported either, and I love Thomas' Aeriel Stryke sub, but damn is that thing big and heavy. :E Maybe I'll try modeling a 120l ported sub and see what I get. I'm at work right now so I guess it will have to wait.

If you can't tell, I'm pretty excited about this project. I just don't want to be disapointed when I'm done so that's why I'm asking advise from the experts. Tomorrow is my day off and I'm ready to go to the BORG and get some MDF! :B

[ThomasW]

Having access to high power doesn't mean you need to use it. If you're going with a really small sealed box I suggest getting one of the pro-sound amps just in case....

The primary problem going with a smaller ported box is that your limited by the port length. These high excursion drivers do better with larger diameter ports and that dictates a longer port.

[PoorboyMike]

OK, so I'm pretty set on sealed so I can keep the weight of the thing managable. After playing around with Unibox a little more, I think I will go with a Q .5 box, which calculates out to around 80 liters.

My question is, when I try larger box volumes, I get a little more extension, but the driver will reach xmax at a lower frequency. What would be better, a 80 liter box with 1000 watts, or a 120-150 liter box with less watts? Or wouldn't I really notice a difference? I guess I could just build a larger box and try putting in some wood to take up some volume and see what I like. I just would like to know before I start this thing if there would be any real advantages to going with a larger box and less watts based on others expierences with sealed designs.

And thanks for the advise given so far. I appreciate the help.

[MDJones]

If you are worried about the weight and are planning on a tube design, a ported sub won't really weigh any more than a sealed sub. If it is size that you are worried about, then yes, a sealed design will be smaller.

[PoorboyMike]

If you are worried about the weight and are planning on a tube design, a ported sub won't really weigh any more than a sealed sub. If it is size that you are worried about, then yes, a sealed design will be smaller.

As far as ported goes, I'm refering to ThomasW's AS15 design, which I'm assuming is about the optimal size for a ported 1503. I would like to build something like that but I don't think I really want a 300 lb sub in the living room. Actually, I wouldn't mind too much, but the wife wouldn't be happy. :M I'm hoping a sealed sub with this driver will sound better and be considerably louder than my 10" Athena, and still be managable for moving it around the room when needed.

I guess I could always rig up a mobile base for it similar to the one on my Ridgid table saw. hehe

[Bent]

What. mine "only" weighed 260 pounds. LOL.

[PoorboyMike]

What. mine "only" weighed 260 pounds. LOL.

Oh, so it's only 260lbs? That's not too bad. lol

So how did you like it before you fried your 1503 and what are you using now?

Did you ever fire that thing up with your boy sitting there? If so, how long did it take you to locate him afterwards? :B

[Bent]

I can't actually say the 1503 "fried", I believe it had an adhesive failure - eitehr the former to cone has come loose, the former to spider joint, or possibly the v/c adhesive/varnish has allowed a turn-or-two to loosen. It is still useable (and is being used), and the performance was absolutely stunning (just not as much so, now).

I don't do anything too "loud" when the kids are around, as the sound pressure immediately at the face of the subwoofer can be high enough/low enough freq. to actually make one feel nauseous - I've never measured it, but to put it simply, if the flares were still available, I'd build another one or two for my friends... I believe in the design completely

[PoorboyMike]

I can't actually say the 1503 "fried", I believe it had an adhesive failure - eitehr the former to cone has come loose, the former to spider joint, or possibly the v/c adhesive/varnish has allowed a turn-or-two to loosen. It is still useable (and is being used), and the performance was absolutely stunning (just not as much so, now).

I don't do anything too "loud" when the kids are around, as the sound pressure immediately at the face of the subwoofer can be high enough/low enough freq. to actually make one feel nauseous - I've never measured it, but to put it simply, if the flares were still available, I'd build another one or two for my friends... I believe in the design completely

Stop it dang it, you're going to get me in trouble with my wife when I end up building that beast. :M

What amp are you using for that sub Bent and what were you playing when the damage occured?

[Bent]

Mine has a 1200 watt Adire Audio ADA 1200 (1200 watts) mounted to the back panel.

I'm almost embarrassed to say that I had a dance remix of Sarah MachLachan's "the possesion" absolutely cranked. dance music doesn't normally go "low", but this one did.
it developed it's rattle about then, and there are no more re-cone kits available for them anywhere.