this question goes out to those who know more about electrical and audio stuff than me, which is pretty much everyone here.

why is it that some enclosed woofers enclose the back of the sub, and why do some enclose the front? what does either one accomplish?

 

As far as I know........the main reason for eclosing the cone, and leaving the back of the sub exposed is that the back of the sub is really "purdy". Some speakers have very nice looking baskets and magnets.........and, likewise, people want to show them off.

I don't know if there is any sort of sound performance benefit to this at all.

As far as I'm concerned........speakers are built to put sound out of the cone of the woofer..........not out of the ___. But whatever floats your *******.

KiL

 

The following is from www.The-Woodshop.com they have been producing a box that has the subs bacwards for quite a while; they actually mass produce it and sell to public.

"Xposed Back Wave

Our "Xposed Back Wave" series is a new concept in enclosure design. It is a unique
design because in this line, all of the magnets are exposed. It seems that the rest of the
world of speaker enclosures is backward. These enclosures are much louder and
mellower and deeper in tone than any standard enclosure, it boggles the mind. We are
still in the process of completing R & D on a complete line of these enclosures to
include; single, dual, trips, and quads in all sizes of drivers, 10", 12" & 15".
Many have been built and have performed very well in competition in several states
earning many first place trophies and many state records.

Look at our competition page to see what we've accomplished.
These XBW designs are the brainchild of Mr. Dugle of Mississippi."


I carry their boxes and have two of their subs and one of their boxes and it sound awesome. It hits hard! As an example, I bought one of those amplifiers off of ebay for $100 or so, it was a 3000 Watt Boss REV3000D; supposedly a Class-D amp putting out 3000Watts (yea right, more like 500max at 20.0%thd). Needless to say, they still hit hard and reached 143.7 dB, I couldn't believe it, and that was in a Toyota Camry w/ no sound deadening, just thrown in.

Now, what actually occurs that causes it to sound differant, I can not explain; however, I do know that all of their accusations are correct.


Dual twelves
Competition Record
7/8/01, Columbus,MS, 161.1,First Pl.,State Record.
31.5"L x 14.5"H x 20"D.

 

From what I understand I agree with KiL. I think that most people leave the rear of the sub out for show rather than sound. Almost all sub enclosures that are made for sound are builty with the cone enclosed rather than out in the open. So from what I know the "backwards" sub enclosures are usually for show.

 

I have done amateur free-lance installation for years now.

Advantages, mounting your speakers backwards (ISO-vent) allows fresh air to pass acrossed a magnet, this has its advantage when using small sealed boxes with alot of power. It also increases availible box volume by removing the speaker displacement from the box.

Disadvantages, It looks stupid sometimes, especially with small, puny, ugly magnets. You can sometimes hear tinsel lead slap much louder than if it was inside the box, especially at high power.

Basically, other than increased air flow acrossed the magnet and increased usable box volume, there is no other reason.

 

For one, that BOSS REV3000D although cosmetically different, is the same as the Lanzar Vibe 1200D and the Pyramid PB2400D. All of which put out around 1200wRMS @ 1 ohm. They have been benched before to confirm this, by Car Sound magazine. Also, the THD is not near what you think it is...

And 143.7 while decent, isn't all that loud. Especially with 1200wRMS.

I love that "State Record" too. 161.1 db. Now, thats an outlaw measurement for one... and for 2 that would NEVER be loud enough to hold a record. You can put the mic in the port for outlaw... and I'll tell you what, you can get a 170 out of a 10" sub with 200w in outlaw.

Ugh. I hate shady manufacturers.

 

oh! and i wuz at best buy the other day where i saw a set of two enclosed subwoofers with one pointing in and the other pointing out. the sub is manufactored by Dual.

 

wassup with this one?

 

JDaniels, did you even go to the homepage of The-Woodshop. I am appauled that you would consider a company that has been in business for over 16 years a "shady" company. They mfg. good quality boxes at a good price. They have an amazing track record and actually have done very well in the competition area. Below are juts a few comps using the box I placed a picture of in my post. By the way, there is no way that the REV3000D put out 1200 watts, I have an MTX 81000D that I put on those same speakers, it really has 1200 watts!

7/8/01 COLUMBUS, MS JEREMY WILLS XBW D212.112CFS 12"/2 SPL OUTLAW 161 FIRST STATE REC.
7/21/01 BOSSIER CITY, LA JAMES RICHEY XBW D212.112CFS 12"/2 SPL & PORT 313.8 FIRST DASH + PORT
7/21/01 BOSSIER CITY, LA JAMES RICHEY XBW D212.112CFS 12"/2 PORT WAR 170 FIRST
7/21/01 PORTLAND, OR DAVE GOODRICH XBW D212.112CFS 12"/2 DB DRAG 145.6 SECOND

Thank you,
Eric.

 

Id like to see a STREET car do 313.8 dBs or 170 dB.

What organization is this?

Here are some other records:





Another Legal B&K World SPL Record Broken Again!



The Story…

At the 2002 USACi World Finals Steve Cook and Michael Jones dominated their competition. The USACI Legal World Record of 172dB was shattered by an amazing 1.8dB when Steve Cook hit 173.8dB and backed it up by an equally impressive 173.7dB. Crossfire teammate Michael Jones proved that he too was one of the loudest in the world by hitting 173.3dB, bettering all other competitors by almost 2dB.

In 2003 Michael Jones got his revenge by destroying Steve’s record, setting the mark at an amazing 175.7dB. This means that Crossfire has now broken and held the USACI Legal World Record 7 times in a row, proving that Team Crossfire has the loudest teammates in the world running the loudest amplifiers in the world…


Michael Jones ’01 168.5dB
Steve Cook ’01 169.4dB
Michael Hughes ’01 169.6dB
Michael Jones ’02 171.8dB
Michael Jones ’02 172.0dB
Steve Cook ’02 173.7dB
Michael Jones ’03 175.7dB

**Bruel & Kjaer has been the leader in sound and vibration measurement since the 1940’s and their products are currently used by leading aerospace and automobile manufacturers such as NASA and Toyota. For more information on Bruel & Kjaer visit their web site www.bksv.com/

 

Eric,

True, the MTX is a higher quality amp, BUT the Boss DOES put out 1200WRMS. Don't believe me? Go take a trip on over to Termpro.com and ask about it, it's old news. Competitors were using them, since they were cheap and effective.

But, those numbers aren't exactly great. I do consistant 150s on the dash LEGAL competing street class in db drag with my garage built boxes that cost me 19 bucks to build.

They're a shady company in my eyes, because I believe they lie about their box design being something extraordinary, which it's not. It's a basic slot vented enclosure.

Believe me, I wouldn't just make this information up... I am a long time competitor/hobbyist/installer, I know what works and what doesn't.

 

those are the ones that sell at best buy, they're like 0.99 cent a piece, buy one get one free.....crappy

 

Please do me a favor and don't ever buy those, unless they're less than 20 dollars.

That's a 4th order bandpass. Poorly made, with poor quality subwoofers.

Bandpass has its place, it's best suited for open air vehicles such as Jeep Wranglers/CJ7's where there is no cabin gain.

It also has it's place in the competition scene, where a narrow band of frequencies need to be amplified.