mrogowski

Hahaha! Pretty good They should be on their way...

Why don't you rebuild the box for the driver you have? You may not have to purchase a new driver at all...

Sub box is coming together. Six cubes per driver. Mach 5 CEO pictured here "supervising" Ports being glued to baffle

I'm sorry you feel that way. Everyone has to start somewhere, and a little praise here and there doesn't hurt. It's all a part of learning and understanding.

Here are more shots of Joel's progress: Another shot of truck He decided to paint his Audison amps - nice A shot of his Eclipse deck going in The MLI's in their pods A shot of his Memphis amp - not sure why the cap is there tho.. Here he is doing some work on the doors (I think)

Nice score!

Here is the crossover design with a response curve. I listened to it for a good hour using a variety of music (rock, pop, jazz - no rap though). It sounds quite balanced. A person can add a resistance circuit if they feel the need to drop the highs a bit. Keep in mind that this is a nominal 2 Ohm load setup so make sure to use a suitable amp to drive it.

Indeed, some plywood is more flexible but that is not because of the way it is made, but rather how dense the wood fibers are. MDF bends under its own weight because the wood fibers are very weak to begin with, are surrounded by glue and do not support each other. If MDF was structurally as strong as it is dense, it would be like concrete. Of course, there is good and bad ply. Many folks here talk about 13 ply Baltic. That stuff is super expensive but superior in all respects. I like to use Fir as it is a hardwood and much denser than your standard Birch. m

Indeed.

Strength comes from fiber length. MDF has fibers that measure at best, a fraction of 1mm in length and are surrounded in glue. Since the structural strength is in the fiber itself and not the glue and the fibers are aligned randomly there is little strength. Plywood however has very long parallel fibers, each supporting the other. On top of that, each layer of ply is positioned at 90* from the other, so you end up with strength in all four directions. Try breaking a ply board - you will notice how much it splinters verses a clean break with MDF.

Agreed. If you plan to rebuild, use plywood for the box and MDF for the bracing. I was chatting with a Civil Engineer friend about it, and he suggested the bracing material be MDF. Reason being is MDF is already compressed to extremes at its edges, which makes it excellent for stopping the box from compressing/expanding. There simply is *no* give there whatsoever. Where MDF fails miserably is in it's structural support (along the flat surface), which is the reason to use plywood instead. All of my finished boxen will use this method from now on...

What is the problem with your original build?

Yeah, I guess you're right. I'll do that.

Sounds like the new model will be a winner. I might as well close up shop now...

Excellent point on the car movement Todd. That never crossed my mind. A person would have to ensure the cabinet is sealed real tight to minimize such things. The weight thing is largely dependent on how strong/stiff your suspension is.

Glad to hear it Aaron. The SEAS tweeter we selected it pretty decent. If folks at DIYMA/here are interested, I'd be happy to post the crossover schematic we will be using.

** Update ** Joel responded with his equipment list: Vehicle: 1999 GMC Sierra Extended Cab Head Unit: Eclipse AVN 5500 Front Amp: Eclipse LPX 4001 (2) Sub Amp: Memphis Audio 4000d Tweeters: SEAS 27TFFNC/G NEO Fabric Dome (2) Mid-Bass: Mach 5 Audio MLI-65 (4) Subs: Mach 5 Audio SPL-15 (2) Mid/High Crossover: Custom designed passive 2-way He will be taking more pics this weekend.

Looks pretty good. The only thing I might suggest you look out for is excessive flexing of the port top and bottom. If you see this occurring glue a brace attaching the two, running from front to back.

Depending on the excursion capabilities of your active drivers, passives and planned input power, this will determine how many you will require. For example. you could squeeze two IXL-10's per one MJ-PR provided you don't drive the subs too much below the tuning of the box. But Jim is right, the general rule for passives is about 2x the cone area/throw to each active driver. Best, Mark

Well, I'm glad you like it. Post up some pictures here, and if you want, throw them up in the Builder's Corner as well for prosperity... m

Yup.

Freezing (this is what I call it) occurs when a driver is placed in a bass reflex with a very long port and is pushed to levels above and beyond normal port compression. At these high levels the enclosure no longer acts as a bass reflex enclosure and for split instants at certain frequencies (if memory serves its at resonance) the driver will actually freeze up. It was a problem years ago as we had to deal with it when designing, but technological advances have minimized this issue. Using port flares is one way. Ensuring that you have adequate port area for the size of driver is another, but this of course, can work against you.

Yeah, I agree. A box that small would definitely be affected by driver volume.

I have soft parts for MAW-15's if you want 15 inch sizes. Send me an email through my website.

0.11 cubes.