Ok, so I'm making a temporary sealed enclosure for all 4 18" woofers I have sitting in my room (Mach 5 MJ18). The enclosure is gonna be 7'x2'x2' roughly 800L.

I need someone to model this with whatever program so I can see what to expect.


Edit: This IS NOT the subwoofer going into the theater, the box will not be used, just the drivers.

Looks pretty darn good if ya ask me! Thats 200w/driver. The final Qtc is ~ .5 on the dot.
http://i9.photobucket.com/albums/a79/Amigo207/CBResponseMach518CQ.gif

112db at 10hz. That seems ok...:P

BTW this is assuming an Le of 1.0...I dont know what the actual Le spec measures on these drivers...overall the above is a good indication of max output from 4 of these drivers in a box that size.

The enclosure is gonna be 7'x2'x2' roughly 800L.
So has anyone built a box yet to look just like a coffin? It'd double as a great conversation piece... "oh, that's my sub".

....where demands are met with enthusiasm!

The box is a bit too big giving a low Q which puts the F3 at a very undesirable 66hz and it is
-16db at 20hz so some EQ might be needed and or a smaller box.

Actually no matter what size the box is you'll have a relatively high f3 with these drivers, with their Fs of 30hz. The larger box ensures good efficiency down in the lower frequencies.

I'd keep the low Q allignment/large box, and incorporate some EQ.

You guys are thinking this too hard.... This is not a permanent project, this is just something I can make to mess with (and test) the drivers until IB is ready to be made. It may even double as a christmas and new year parties subwoofer.

Oh Exocer, how do you get 112db from that graph, I see only 102db at 10hz ???

....where demands are met with enthusiasm!

My Winisd was acting stupid so I figure someone on here has to have the specs for these cheap-o drivers already saved on their modeling programs.

This is not a permanent project, this is just something I can make to mess with (and test) the drivers until IB is ready to be made.
Ahhh! your doing an IB with these eventually. That should be real nice with 4 18"s.

Ahhh! your doing an IB with these eventually. That should be real nice with 4 18"s.

Yup yup yup!

I just want to experience the subwoofage so I can get an idea on what to expect from the IB.

man, you guys are anal!!!! heheheh....I love you guys! :p :D

yo chris, you still going to chuck's this weekend?

man, you guys are anal!!!! heheheh....

Pot, meet kettel!

Mister I only want a driver with a silver cone, and mister I hate seams, I can't handle two visable seams.


Sheeeeachhhhhhhhhh!
:)

Pot, meet kettel!

Mister I only want a driver with a silver cone, and mister I hate seams, I can't handle two visable seams.


Sheeeeachhhhhhhhhh!
:)
tis true! :D

but the man just wants a weekend project to play with until he is ready to isntall the IB! :p

yo chris, you still going to chuck's this weekend?

Yeah, but I gotta build the coffin on friday for the drivers (as Darin calls it).

Can anyone answer me why Exocer says 112db at 10hz when all I see on his graph is about 102db?

Yeah, but I gotta build the coffin on friday for the drivers (as Darin calls it).

Can anyone answer me why Exocer says 112db at 10hz when all I see on his graph is about 102db?
LOL....the coffin!! that's classic! :) hehehe.

Exo just made a typo.....it's 114dB @ 20hz, and 102dB @ 10hz......pretty freakin awesome if you ask me!

Can anyone answer me why Exocer says 112db at 10hz when all I see on his graph is about 102db?
I'm gonna guess either a typo or he just read it wrong if the model is right. Quickly glancing at it, the 100db level can look a little like 110. These drivers aren't very efficient down low and don't have lots of excursion to spare, so I wouldn't expect too much low end.

Yeah, I figured it was a typo, I was just making sure he didn't have another graph or something that he didn't post.

I'm still not sure what exactly to use to build the box. I have plenty of 5/8" scrap plywood nextdoor. I figure using double 5/8" to make the bracing, and double up on the baffle, the rest of the sides with a single layer should be fine.

Bracing on all walls except for baffle (ThomasW-style), and some shelf bracing in between the drivers.



I figure I can drill some small holes in the back and run some 12awg wire to get them ready for the amp, then seal the holes with epoxy or liquid nail.

800 liter, double wall, braced, and sealed enclosure as something to use just to mess around with? :o That's some dedication. Even with plywood, it's gonna be HEAVY. Have you considered maybe going smaller and just using lots of fill?

800 liter, double wall, braced, and sealed enclosure as something to use just to mess around with? :o That's some dedication. Even with plywood, it's gonna be HEAVY. Have you considered maybe going smaller and just using lots of fill?

Oh c'mon Steve, you should know the best about going big with the enclosure, you're not wimping out on me are ya? :p

Well, I forgot to mention that the face of the box is basically the IB's future manifold, for the IB we are just gonna take off the back end of the sealed box and stick it in the roof.

We have upgraded our idea of fastening the box, we will probably arc-weld some braces from steel truss to steel truss then mount the IB to that. We were worried that the vibration from the IB could affect the integrity of those little metal anchors in the concrete deck.


Edit: Coffin will be built on Saturday, testing will commence on Sunday.

I'm not wimping out on you, but wanting to build a disposable double wall, adequately braced, 800 liter, sealed enclosure that will get used for a few weeks is probably where I draw the line :p There, you've exposed my limits. Wouldn't two drivers in 400 liters suffice for messing around?

Oh sorry for the typo.

Chris, looks like we've got similar numbers.

I'm not wimping out on you, but wanting to build a disposable double wall, adequately braced, 800 liter, sealed enclosure that will get used for a few weeks is probably where I draw the line :p There, you've exposed my limits. Wouldn't two drivers in 400 liters suffice for messing around?

I think you didn't read part of my post, the front baffle and all sidewalls of the sealed enclosure are going to end up being the manifold for the IB. All I am doing for the temporary sealed sub is adding a back panel.

And used for a few weeks... this will only be a sealed enclosure for about a day and a half unless I buy a 2500.

Interesting to say the least...

Interesting to say the least...

Hahaha, you know your woofers are tempting me to do this.

I can't imagine 4 of these 18" drivers not being enough for most dedicated home theaters.

But we all know how it is...once you get lots of bass you only want more ;) I suspect Chris might be ordering another quadruplet set of drivers in the future for even MORE headroom ;)

I can't imagine 4 of these 18" drivers not being enough for most dedicated home theaters.

But we all know how it is...once you get lots of bass you only want more ;) I suspect Chris might be ordering another quadruplet set of drivers in the future for even MORE headroom ;)

In a year or two I will upgrade to some 30mm xmax 18's.

Until then, I guess I'll have to deal with having only 4 12mm xmax 18" drivers. :D

Woah, 30mm xmax 18" drivers? INSANE hahaha.

I thought Sherv was sick :p

Are these the upcoming mach 5 high excursion 18" drivers by any chance?

Woah, 30mm xmax 18" drivers? INSANE hahaha.

I thought Sherv was sick :p

Are these the upcoming mach 5 high excursion 18" drivers by any chance?

I don't plan on upgrading any time soon so time will tell what I'll upgrade to. :p

Yeah fair enough...you haven't even completed this project yet ;)

How to make an audiophile subwoofer in 2 hours and 30 minutes.



Step 1. Make the baffle out of a single layer of 5/8" plywood and cut holes using a Sawzall.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00268.jpg




Step 2. Find the most dirty termite infested 2x4 members to stiffen the front baffle because everybody knows, the more rotten the wood, the faster the bass.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00270.jpg




Step 3. Make the back of the sub like the front, the wood bracing doesn't have to match or be the correct length, because if it does, the sub won't be musical.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00269.jpg




Step 4. Put it together with sides, who needs bracing on the side walls, it will make the subwoofer heavy and in turn, it will sound heavier (not good) Besides, who uses braces? That's right, only losers and nerds; your audiophile subwoofer is no punk.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00271.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00272.jpg




Step 5. Put in audiophile grade cable that is a multitude of colors with no red cables because they are inherently slow (which is why stoplights and signs are always red)Put in drivers. Sealants are not needed because it will muddy the sound.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00273.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00276.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00277.jpg

Nice.

Step 6 Use the proper audiophile amplifier to test the subwoofer.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00274.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00275.jpg




Step 7 Put wheels on it. Everything with wheels is inherently fast by nature. Your bass will be faster by association.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00278.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00279.jpg





Step 8 Load audiophile subwoofer into a fast car. Preferably the color red since red cars are faster than regular cars, unlike red wires which are slow.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00283.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00282.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00281.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSC00280.jpg

:D :eek:
That thing is pure badass.

Funny comments too haha my favorite was" Load audiophile subwoofer into a fast car. Preferably the color red since red cars are faster than regular cars, unlike red wires which are slow."

That isn't going to work ,you need to add more drivers on the side panels if you want to achieve any decent SPL. :D

Do NOT rest any drinks on top of that sub! Between the leaks and enclosure resonances, it's gonna be pure audiophile bliss :)

For people who are new to this section, you might wanna put a disclaimer on this project.....otherwise I fear we are gonna see a crop of similar projects....amd the sad part is that it's probably true :)

In all seriousness though, the subwoofer sounded really really good for its ****** enclosure.

After running the sub through a quick warmup, Chuck decided to put on master and commander and got his LLT to bottom out at the same level mine was breezing through. :eek:

I will admit, his sub dug alot deeper and cleaner then mines, then again, I had no eq and had a real ****** box.

Chuck decided to put on master and commander and got his LLT to bottom
:eek: http://www.diyaudio.com/forums/images/smilies/shutup.gif ;)

:eek: http://www.diyaudio.com/forums/images/smilies/shutup.gif ;)

Ok, before SteveC brings out the American Gladiator Hammer of The Dead I will explain.

First my sub was put on with the volume very loud to begin with and the BFD off, he then just switched the wires straight to his sub without playing with any levels.

His sub sounds awesome and can play very loud, but in all fairness, I had 4 drivers and 10 liters of displacement to play with.


EDIT: So people can understand, the amp's load was spread to 4 of my drivers which overall played around the same level as his LLT. When he plugged the LLT back in, he didn't mess with any settings so I can ASSUME that the gain was way high.

:eek: http://www.diyaudio.com/forums/images/smilies/shutup.gif ;)
oh oh ;)

After running the sub through a quick warmup, Chuck decided to put on master and commander and got his LLT to bottom out at the same level mine was breezing through. :eek:

I'm sorry, my mind hasn't really moved past that comment :eek:. So was it a really loud "clank" or a soft "thud" you guys heard?

I'd expect your quad sub to never bottom even with lots of power(of course that depends on how much power we're talking...but nothing within the pmax of each driver), at least not until EQ is thrown into the mix...

I'm sorry, my mind hasn't really moved past that comment :eek:. So was it a really loud "clank" or a soft "thud" you guys heard?

I'd expect your quad sub to never bottom even with lots of power(of course that depends on how much power we're talking...but nothing within the pmax of each driver), at least not until EQ is thrown into the mix...

It was definitely a clanker, I know the sound that TC Drivers make when they bottom. ;)

But he was really blasting it loud when it happened.

It was definitely a clanker, I know the sound that TC Drivers make when they bottom. ;)

But he was really blasting it loud when it happened.

Yeah man, I still don't understand how that happened with a HP. He does still use a HP right?

Lol, I like the anticipation :)

Chuck can correct me if I am wrong, but I think the dirty little secret is that he isn't amp limited. He's powering each voice coil on a D4 driver with 750 watts as opposed to using a D2 wired in series off one channel.

Yeah man, I still don't understand how that happened with a HP. He does still use a HP right?

I edited my post a little bit so you can understand a little better what took place before it bottomed.

Lol, I like the anticipation :)

Chuck can correct me if I am wrong, but I think the dirty little secret is that he isn't amp limited. He's powering each voice coil on a D4 driver with 750 watts as opposed to using a D2 wired in series off one channel.

Yeah, he is powering each VC with the 750watts. But don't get me wrong, the EBS LLT whatever you call it sounds very good and can dig down deep and stay 'tight and fast'.

If I couldn't do an IB I would definitely build one...... or four.

Yeah, thats a lot of power. ;)

Chuck can correct me if I am wrong, but I think the dirty little secret is that he isn't amp limited. He's powering each voice coil on a D4 driver with 750 watts as opposed to using a D2 wired in series off one channel.
ahhh...I seem to recall this coming up in the past. :)

Heck of a rig you built there Chris, the new standard in Quick Sub. :cool:



.

In all seriousness though, the subwoofer sounded really really good for its ****** enclosure.

After running the sub through a quick warmup, Chuck decided to put on master and commander and got his LLT to bottom out at the same level mine was breezing through. :eek:

I will admit, his sub dug alot deeper and cleaner then mines, then again, I had no eq and had a real ****** box.

Point to clarify! Neither sub was EQ'd. I had disabled the BFD when I was running Chris' 4 Mach 5's and did not re-enable it when running mine. It bothered me that it clunked very loud and hard, so I reran M&C after Chris left with the EQ on. No clunk!

I'm sorry, my mind hasn't really moved past that comment . So was it a really loud "clank" or a soft "thud" you guys heard?

I'd expect your quad sub to never bottom even with lots of power(of course that depends on how much power we're talking...but nothing within the pmax of each driver), at least not until EQ is thrown into the mix...

It was a loud clank. As for power, the drivers are 8 ohms each, and so I paralleled 2 per channel which gives about 650 to 700 per channel from the EP2500. Approx. 350 watts per driver. My tube runs with 650 watts per VC for a total of 1300 watts for one RL-p15 driver.

Lol, I like the anticipation

Chuck can correct me if I am wrong, but I think the dirty little secret is that he isn't amp limited. He's powering each voice coil on a D4 driver with 750 watts as opposed to using a D2 wired in series off one channel.

Steve is correct. No amp limited, just careful calibration and a steady hand on the throttle (until I forget to put the EQ in). I have taken the High Pass filter out because I found I did not need it and found that I liked the sound better without it. The HP was built for 17 Hz fixed and that is too high for me. I am going to rebuild (with all my spare time) with a different frequency point later on. Actually what I am working on doing is building a unit where different modules can be inserted for different frequency points and adding phase control along with balanced +4 and unbalanced -10 outputs.

ahhh...I seem to recall this coming up in the past.

Heck of a rig you built there Chris, the new standard in Quick Sub.

Yeah Steve, kind of makes your wimpy dual 15 look, ummm, wimpy! I really think Chris should put some veneer on that cabinet to spruce it up.

In all seriousness, after seeing these drivers in person and getting to play with them a bit, I believe they are perfect for an IB. When you want to use multiple drivers with lower wattage needs in an IB situation where the drivers are set up to just sort of coast along without ever being stressed to the limit, these are perfect. Even at $100.oo each shipped from Canada, if Chris needs to, he can just drop 4 more and an amp in his HT . I mean, we are talking about $700.00 to put in an EP2500 and 4 18 inch drivers! For an IB it is champagne taste on a beer budget. Obviously not everyone can have an IB, but if you can these are a very attractive driver. Other manufacturers are "coming out" with an 18 inch model "shortly", but these are here and available now and don't forget the price.

Chuck

In all seriousness, after seeing these drivers in person and getting to play with them a bit, I believe they are perfect for an IB. When you want to use multiple drivers with lower wattage needs in an IB situation where the drivers are set up to just sort of coast along without ever being stressed to the limit, these are perfect. Even at $100.oo each shipped from Canada, if Chris needs to, he can just drop 4 more and an amp in his HT . I mean, we are talking about $700.00 to put in an EP2500 and 4 18 inch drivers! For an IB it is champagne taste on a beer budget. Obviously not everyone can have an IB, but if you can these are a very attractive driver. Other manufacturers are "coming out" with an 18 inch model "shortly", but these are here and available now and don't forget the price.
The only "issue" I have noticed, based on measurements of IB's using these drivers over at the Shack, is that the low end efficiency is kinda poor. For the price, you really can't complain, but the subsonic stuff won't be very powerful.

The only "issue" I have noticed, based on measurements of IB's using these drivers over at the Shack, is that the low end efficiency is kinda poor. For the price, you really can't complain, but the subsonic stuff won't be very powerful.

Yeah but with some major EQ it can be really improved.





Heck of a rig you built there Chris, the new standard in Quick Sub. :cool:


Thanks! It was real fun to build and test. We now have it running off the sony boombox in the new house running full-range. Good thing the sony has a 6-band eq! :D

My friend let me borrow his old Onkyo reciever. Oh my god if I am not getting at least 120db from regular car sub frequencies something is wrong, lol. We were BLASTING car sub music, chips of cement started falling off the wall.... it hurts to breath.... all while playing completely ful-range from the amp. It sounded awesome (besides all the air-leaks resonances, etc...)

I have made a monster... My ears hurt so bad, next time I am definitely wearing hearing protection... My ears are even used to loud booms and gunshots from recreational shooting.... but man, a whole other experience.

My ears hurt so bad, next time I am definitely wearing hearing protection...
Or you could spring for a higher end receiver that has a volume control. :D

We even had my portable DVD player hooked up to the sub playing WOTW. The first tripod coming out of the ground was amazing. It sounded like the house was coming apart.

Batman Begins was crazy too.

The bass was strong enough to really shake the 4" concrete deck of the second floor. :D

THAT is a lot of bass ;)

THAT is a lot of bass ;)

Yes, now comes the tedious process of getting rid of every in-room resonance and sealing every single gap and seam and somehow trying to keep the majority of the sound energy inside the theater and not the rest of the house. :(

Best of luck with that Chris.

I often find that room "rattle" becomes REALLY annoying with high output subs...If only i could find what the heck is rattling :rolleyes: and hammer it down ;)

But honestly I couldn't imagine how much output you're getting with 10liters of displacement. My sealed Tumult with a bridged Ep1500 was the most bass I've ever heard. You're at roughly twice the displacement of my Tumult :D That has got to be a blast to experience. Once you have some good EQ dialed in and something other than a Sony boombox behind it you're in REAL business.

Best of luck with that Chris.

I often find that room "rattle" becomes REALLY annoying with high output subs...If only i could find what the heck is rattling :rolleyes: and hammer it down ;)

But honestly I couldn't imagine how much output you're getting with 10liters of displacement. My sealed Tumult with a bridged Ep1500 was the most bass I've ever heard. You're at roughly twice the displacement of my Tumult :D That has got to be a blast to experience. Once you have some good EQ dialed in and something other than a Sony boombox behind it you're in REAL business.

Yeah, we are powering it now with my friend's spare Onkyo reciever. Im not sure of its wattage but its probably about 75watts for each channel. We have it wired 2 and 2 drivers together in parrallel to make a 4ohm load. From there hooked up to the front left and right channels on the reciever.

LOL

Why not just make it into a trailer and tow it behind the truck KABOOM, BOOM KABOOM!

Mate I sure hope you sealed all the holes around that to prevent any noise, play a steady sine wave at 20Hz and walk around it placing your palm against the sides the back the fronts and feel for any air passing though it. If you can sense any seal it! This will tighten the low end up!

LOL

Why not just make it into a trailer and tow it behind the truck KABOOM, BOOM KABOOM!

Mate I sure hope you sealed all the holes around that to prevent any noise, play a steady sine wave at 20Hz and walk around it placing your palm against the sides the back the fronts and feel for any air passing though it. If you can sense any seal it! This will tighten the low end up!

Haha, the air leaks on this thing can blow out a candle :p

But even if I did go through all the hassle of sealing it, it's only going to be a sealed sub for a few more months before we trash the enclosure.

it's only going to be a sealed sub for a few more months
Ah ha! See...see :D

I'm not wimping out on you, but wanting to build a disposable double wall, adequately braced, 800 liter, sealed enclosure that will get used for a few weeks is probably where I draw the line
And used for a few weeks... this will only be a sealed enclosure for about a day and a half unless I buy a 2500

Well SteveC I didn't know that my friend had a spare Onkyo reciever that he found on the side of the street that still works!

Hi Chris,

Its been awhile since I've been here and you have obviously been busy! Those shots of the box in the truck was great - you should have stood it on end facing the rear to show folks what they're missing. :D

Glad you like the units. Just don't blow out your ears! I'm not liable... ;)

Best,
Mark

Hi Chris,

Its been awhile since I've been here and you have obviously been busy! Those shots of the box in the truck was great - you should have stood it on end facing the rear to show folks what they're missing. :D

Glad you like the units. Just don't blow out your ears! I'm not liable... ;)

Best,
Mark

Well Mark you would definitely benefit if I blew out my ears... then I'd have to buy more woofers to make it sound as loud as it used to! :D

I can't wait to get these in the IB

:eek: :eek: :eek:

I could imagine visible sound waves coming from that thing! :eek: :p

where is a picture of sub in the theatre ?

does diet soda affect the performance of the sub? :D

where is a picture of sub in the theatre ?

does diet soda affect the performance of the sub? :D

Don't get too jealous of my expensive gear.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/ent-center.jpg

In a year or two I will upgrade to some 30mm xmax 18's.

Until then, I guess I'll have to deal with having only 4 12mm xmax 18" drivers. :D


I've got four 18's (soon to be six) with close to 30mm one-way xmas :D They are very nice, and having lots of headroom is wonderful. Those new Mach 5 drivers should be great for the price.

JP

Hmmmmm.... http://www.coffinitup.com/sub2006/speakers.htm

Naaaah.... Not big enough (nice thought tho.)
A car nut buddy picked up an OLD hearse and started to restore it... never finished.
I had visions of a bomb-bay door roof and raising a real casket on hydraulics with that kind of woofage... doors that creaked open with a plastic skeleton hanging on thin bungee (thin for extra bounce) and blasting some Greatful Dead. So many "best laid plans" are laid to rest, unfortunately.

I don't remember what happened to the antique hearse.

I've got four 18's (soon to be six) with close to 30mm one-way xmas :D They are very nice, and having lots of headroom is wonderful. Those new Mach 5 drivers should be great for the price.

JP

Yeah I'm waiting for those in particular to come out.

You may be asking why this thread is being resurrected. Well it's just because I can't find my IB thread here. And work has been started on building the IB.


Used a piece of 1/8" aluminum to create the stencil / circle-guide on the router.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0048.jpg



Making marks.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0049.jpg



First hole cut!

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0050.jpg



Number 2; MDF dust (YUM, smells like popcorn!)

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0051.jpg



Almost there...

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0052.jpg



Complete with holes.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0053.jpg

Here is the very rough layout of the manifold. It will be like an extruded triangle with the drivers installed in the top and the point of the triangle towards the roof and the bottom part towards room. There are going to be two of these manifolds and two drivers in each.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0054.jpg

Wood pieces will be glued braced and fastened together tomorrow.

That's one heck of a big fan you have there...

That's one heck of a big fan you have there...

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0053.jpg

I hope you aren't talking about the orange fart pusher.... In the rear right of the picture behind the ladder is the real fan. It is 20A and has a fin-span of four feet. it came out of one of my Dad's friends house. Houses in South Florida used to have gigantic fans in the attic, because the lack of affordable AC. With the flip of a switch, giant vents would open and WHOOOSH out went the bad air.

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0055.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0056.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0057.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0058.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0059.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0060.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0061.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0062.jpg


http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0063.jpg





We still need to cut the center stud on the left manifold as well as adding bracing.

Only single ply on the manifold?

Were you posing during the router pics or do you really route MDF without a mask?

Be sure to brace straight up to the roof joists if possible.

Should sound awesome!!

so chris....you got your own "chuck" too? :p Who is the old bald guy with the white goatie in these pics? lol


congrats man, coming along nicely.

cecaa850: Yeah, these manifolds are so small that once we are done with bracing and everything adding a second layer would just mean more weight. It's not like we are snorting the MDF dust :p we got those fans running full blast to blow the dust away and out the house. That's the old man, not me, I was taking the photos. I'm thirty-something years younger with shaved head and beard. We are still working on the whole bracing situation And I'm considering running the drivers that are near the center of the two manifolds in reverse so the manifolds can be directly side to side.



Sherv: Don't you notice the resemblance :p The only reason I'm not in the pictures is due to the fact that my old man is an enemy of any electronic device. Last time he used my computer he ended up hammering my mouse into the computer table with his fist.

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0064.jpg

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0065-1.jpg

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0066.jpg

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0067.jpg

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0068.jpg





Manifolds are installed and braced. Paint needs to be touched up where the bracing was installed. Driver was test fit and works fine both facing the right direction. Manifold is located front center-left and front center-right (not on any room modes)

Lookin' good Chris...

so chris....you got your own "chuck" too? :p Who is the old bald guy with the white goatie in these pics? lol


congrats man, coming along nicely.

The 'bald guy' with the 'white goatie' is the one that knows all on this job!

Looking good, Chris. I can't wait to get down and see it soon.

Chuck

The 'bald guy' with the 'white goatie' is the one that knows all on this job!

Looking good, Chris. I can't wait to get down and see it soon.

Chuck

You can swing by whenever you want!

We probably won't fire it up until we have the drywall done in the room. I already have him wanting to paint the room black :p

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0071.jpg

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0070.jpg









Aggressive!

http://img.photobucket.com/albums/v202/zer04evr/House/DSCF0069.jpg

Still some minor issues to attend to (like rattles and the sorts) before we finish up the drywall. Needs to be painted over caulking also. The small amp can easily bring the subs to the limit because of the high sensitivity ( I guess). Soffit movement is barely noticeable knocking at full power so shaking is a non issue.

The major issue is rattles because the AC vent is directly behind and the straps are made of thin galvanized steel so you can guess how that sounds. And also the recessed-lighting rattles bad too. So this week we'll be finding every little rattle before we put up drywall.

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0073.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0074.jpg

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0075.jpg




And a picture from all the way in the back of the theater which has not been this clean since Christmas Eve....

http://i2.photobucket.com/albums/y22/crackyflipside/ht/DSCF0072.jpg

crazziness....

I like the wheels :)

I'm very, very impressed!

Did you order some IXL-18.4?

I'm very, very impressed!

Did you order some IXL-18.4?

Nah, I gotta enjoy the MJ18s for abit before I change them.

Looking very good cracky, I am a lil sad to see your old "audiophile" subwoofer enclosure go though, will change the avatar now?

Hey guys, got down to doing some semi-proper tests with the IB using a weak 75w amp, but thanks to the very high sensitivity, it went well. The IB is now properly sealed and is complete pending it's proper amplification.

All dB numbers on the post are as read on Radioshack SPL meter, no calibration.

I just wanted to see the roll-off of the IB. (all numbers are uncalibrated) I first ran a sort of benchmark at 20hz then dropped the frequency. It seemed the subs roll-off is at about 13-12hz because below that, there is no pressurization felt (although probably with SPL correction values it still is flat). It is strange because if you stand directly below the manifold you hear nothing at all, not even a sense of pressurization. Once you move back about 10ft it gets obvious as the ambient sound in the room begins to oscillate at low frequency and if you get to the back wall it gets ridiculously more powerful.

I tested it with 15hz to observe the phenomenon. I put the tone so at listening position it was 91dB(~15ft away). 1ft away from either manifold it was 88dB... at the back wall it was 98dB.

These were done at listening position
90dB at 20hz
88dB at 15hz
86dB at 12hz
84dB at 10hz (no sense of pressure or room activity)

So the sub system is flat to the low teens and I was able to reach a corrected value of 110dB @ 15hz (uncorrected 98dB@15hz) but I didn't want to push the system further since the amp was so weak. It did look like the drivers were nearing excursion so that also made me stop here.

Let me know when it will be time to bring a real amp and some decent test gear down to see what it will really do! You might be very surprised how well it can do. :D

Chuck

I'm guessing it was impossible to IB the 4 of those 2 front/2back to even out room response?

I lol'd at the 2.5 hour cabinet, good stuff. The rest looks like fun too, grats on the set up.

I'm guessing it was impossible to IB the 4 of those 2 front/2back to even out room response?

I lol'd at the 2.5 hour cabinet, good stuff. The rest looks like fun too, grats on the set up.

If you put 2 front and 2 back you would have phase issues with the sound arriving at very different times and the room response would probably be dramatically more erratic with some possible cancellations happening.

With an IB, you can't really 'play' with positioning like you can with a box sub.

I did model the room to find the right locations (avoiding modes and the such)

Cracky, good to see you on here again! It seems like I haven't seen you here in a long time! I always loved this low cost IB build, nowadays, folks are going with higher xmax, higher value drivers, but I still love the MJ-18!

Cracky, good to see you on here again! It seems like I haven't seen you here in a long time! I always loved this low cost IB build, nowadays, folks are going with higher xmax, higher value drivers, but I still love the MJ-18!

There is something to like about the cheap guy still getting really good results! :D

Haven't been on here in a while, mostly because of school and my new hobby of Olympic weightlifting.