No more 60 degree, but I still have an old Kicker 10" s

[weisinator]

And it's getting a massive Tapered Quarter Wave Pipe enclosure:



I masked and primed the bottom board of the enclosure so I could see what I was doing while I was putting together the enclosure. That and my Trig sucks.

I have several more construction and finished enclosure pics, but I have two more pics on the roll. I own no digicam.

I learned a bunch about these designs at www.quarter-wave.com and figured I had to try one out. I've been intrigued by quarterwaves since the summer of 1996 when I picked up a copy of Speakerbuilder and read about the theories behind the design. I thought they'd be too big for a car.

Externally the box is 34x18x11.5. I'll lose 60% of my Cavalier's trunk with this box, but it's not too big. I never use my trunk anyways.

The "bierbitzch" is a marker for a contest I entered to prove that I really built it.

I haven't listened to it yet. I got the carpet stretched and glued at 9:30 last night. I figured I'd give the liquid nails some time to cure before playing music through it. Tapping the cone causes a really deep resonance.

I'm not kidding when I say blowing across the terminus (small open end) causes a resonance like blowing across a beer bottle, only deeper. You have to blow really hard though. I should utilize the air compressor.

I'm gonna burn a tone CD tonight (2khz "normalizing" track and 150-20hz steps in 5hz increments) and measure some differences between this and the 0.8 cubic foot sealed box I have sitting in the garage.

[RidgeRunner]

Hey Tim, you wanna build me a box for my BA Proseries ten? :-D jk

[weisinator]

MDF = heavy, Shipping = expensive

[bszopi]

Awesome. Definately interested in hearing the outcome!

[weisinator]

I'm interested in how it sounds, too. I haven't had a chance to hook it up to anything yet. It's sitting across the room, staring at me, telling me that I have an old Marantz receiver in the next room that can handle a four ohm load.

The only thing I can definitely say is that it weighs 62lbs.

[Juglenaut]

You can tune the box by placing a small port in the very inner chamber wall close to where the sticker is. This will allow flexibility in design for Q'ing in different speakers response curves, for speakers that don't move that much air, and so on.

Looks nice

[weisinator]

Porting it anywhere would defeat the purpose of having a quarter-wave pipe, since the whole thing is basically one giant port.

Not my picture but it was my design inspiration:



I played with it until 1:30 last night. I didn't have it loud, but it did a good job of filling the room with bass when playing some old-school Chemical Brothers and even older White Zombie (already in the changer)

Tones revealed one of two things:
1) the enclosure introduces a dip between 80-110hz and pounds like hell at 45hz

OR

2) my rec room introduces a dip between 80-110hz and a boost at 45hz.

I won't know until I actually test it against the sealed enclosure with the dB meter. I don't have a lab, so I gotta control what I can.

The thing unloads at 20hz. It was a bit scary to see how little power it took to make it move that much. I might invest in a subsonic filter.

[Guest]

Sweet, not too many people actually know about transmission line type enclosures, usually only us old school guys.

Get some finished pics up.

[Lyle's GTP]

Looks like a shitload of port noise to me.

Lyle

[weisinator]

Looks like a shitload of port noise to me.

Lyle

Well, if you hear with your eyes...

I had the ducting throughout most of my house rattling at 40hz this evening. I only had the volume at 3/10 on a ~125x2 marantz receiver. It's exceptionally clean, too.

Sounds pretty good getting full range orchestra pieces, too. Cellos, concert bass drums and tympanis are very separated. I actually think it sounds better than the sealed enclosure did.

My opinion will probably change when I get it into the car.

I really need to install my amp and fronts in the Crapalier. I haven't had a proper car audio system since my Lumina and I parted ways.

[Juglenaut]

I was just saying to offer flexiblility in design, not all speakers will sound the same as a Kicker 10. There are different resonances involved. The hole would only be about 1 inch inner diameter then tube it to length for a given amount of relief. So the air pressure(resonance) is just releaved into the second stage of the port canceling some resonace out before the second stage, not to much air pressure would be different between the sides of the first stage wall it is the resonant that will be affected. Adjusting this will raise and lower box resonance to the speaker Q for maximum speak output.

Now that I see a better rendering I realize that using a port may cause whistling, but by placing a buffering medium will keep only the high frequencies going through the port.
My friend had one of these types in his 280Z and it had two holes that pointed right to the speaker on the first stage. His kicks butt.

Our looks like it would kick arse and I wish I could get one.

[weisinator]

The design is incredibly flexible as it is. I'll fire up MathCad Explorer 8 tonight and show you how different woofers react in this enclosure. I'll make graphs for the Kicker, a Dayton Qu4tro 10 and a Resonant Engineering XXX10.

Higher frequencies are irrelevant. It's a subwoofer. The mathcad sheets I point to above allow for line stuffing, which controls upper-frequencies at the expense of bass output.

Besides, if I was switching woofers, it would probably be because I didn't like how the Kicker sounded, and therefore would want the enclosure to sound different.

[weisinator]

As promised...

Kicker's response:


Quatro Response:


XXX10 Response:


The responses aren't as flat, but the other speakers in the same enclosure are a good 1/4 octave* deeper.

* 5hz/(40/2) = 1/4