John, I was with ya on the construction for awhile there until you said; "the bottom would be an insert instead of a cap", it seems so obvious the bottom plate would be relocated, but since you mentioned it, makes me wonder if I missed something there.  I understand we're talking adding hieght to the enclosure, but are you saying attach the extra wood to the SIDES of the box extending lower? Then I see how the cap plate would fit inside.  What kind of numbers we talking here for extra box length, port length and diameter? WinISD program is at home, I'm not. Wanted to get started on construction in my head. ( besides, like I said, I know just enough about the software program to ruin some wood.  ::) )

I'd almost be willing to build the TT and start my collection of subs to fill the hz/db gaps if needed. I've got an older Sony stereo receiver that does 100wpc I could use. But would rather alter what I've got.

Bob

Additional charts are provided in the plans and have been discussed in the forums.  The 120db figure is obviously not 1w/1m but what someone measured, not predicted responses.  These figures also do not apply to the TT, I was referencing the T36 if that wasn't clear.  

There's no point to arguing with imagined numbers. It serves no greater good.  Any figures I quote are going to be measured responses.

If all you care about is an octave and a half, BP is right up your alley and I wish you all the enjoyment it can provide you.  Audio is too much a subjective topic to have a right and wrong answer.  I want as many freq's as I can get to sound the same.  That's just me.  

For my purposes, my overcompromised horn is a better performer than the HWK ever could be.  I'm not going to try to shove my beliefs down anyones throat and tell them what they should like.  

My opinion, and it's just that, the best solution is to ditch the HWK and build a horn enclosure.  If that doesn't work due to desires/sunk costs/taste/etc then disregard.  

Unfortunately I do not have the knowledge of bandpass enclosures to offer any advice on modifying the HWK so I don't have anything else positive to contribute.  

problems solved with this

Bob, if i had 1k$ i'd jump on an rl-s 15 and a 2kw pa amp. but i don't have that money.  :D
sure i'd lend you a couple grand.
it's too much xmax (38.5mm) for the hwk. it would blow up  :D

Well Adrian the thing is, I've got this house wreckin' beast in my room that I'd like to tweek. Sure there's some pretty sexy looking units out there that have more than peaked my interest (grass is always greener) but I was trying to stay monogomous [sp?] if you know what I mean. Would love to have the ability to have several to swap/play with, I've got plenty of space, but it's not possible.

EBS? have heard of it, forgot what it means. Please refresh my memory...

Bob

John are you teasing me?

Bob

Bob do not get rid of the HWK. Just build another sub, of course on a budget, to complete the circus. WO36, WO32, or some of John suggestions that could be located in front of you to play lower bass than the HWK and use the HWK to fill in what you might be missing(50Hz to 100Hz). The klopping noise is the speaker being over driven to the point of bottom out just like the others said. With the amp only turn up a quarter of the way it seems that you gains on the receiver might be set to high. Not that I am the master of adjustment but when I play the movies you talked about with excessive gain on the receiver my HWK15 sounds like the "Budweiser Beer Wagon" pulling up to the front door and loudly I must say(klop/klop/klop). Just my "Brain Wiped" two cents.       HT-EXT

Bob,
I wouldn't even worry about WinISD, since it won't model the center chamber.  Just go with Dan's dimensions for the big chamber and build it with an extension to your current bottom chamber.  To get it to his size just do the following (You'll need a sheet of plywood plus enough for say 3 or 4 shelf braces similar to your current driver cutout baffles, but only 1 thickness is needed, and a new end cap, same as your current one but the new interior dimension will be the same as your original cab exterior dimension):

Cover the 2 current bottom port holes from the inside.

Cut 4 side panels-  48"x (current exterior width + 1 material thickness).  I go a tad wider, then use a flush bit for the router to perfect the edge after assembly.

Cut 3 or 4 braces-  Original cab exterior width X depth.  Make a big cutout for air flow (driver cutout size should do the trick).

Now if you didn't do wrap around assembly the first time, you get to learn the easy way.  Attach the braces to one panel, flush with one edge.  Then, starting at the non-flush edge, attach the other panels one at a time to the existing panel and braces by wrapping them around the braces.

To make it so you can take it apart and get to the bottom driver but get a good seal, build a sealing ring on the interior of the new construction 4" from one end.  Say four 1" peices of material forming a ring around the interior, 4" from the end.  Using foam rubber as a gasket on that ring, it will give you a seal when you slide the end of the original cab into the new construction and attach it with screws.

Build your end cap the same way as the original.  I'd put the port in the end for simplicity and go with a temporary straight port at first and try a few different sizes for desired tuning, starting with Dan's recommended 4" by 17".  You'll probably settle on something a little shorter (higher tuning), since the other end is tuned a little higher than Dan recommended.  Once you get the tuning you want, buy flares for both ends.  I'd replace the coffee can port with a real flared port too, unless it has zero port noise.

That should give you impressive extension, eliminate the whacking noise, and make you feel like you're inside the fish tank when Darla taps on it in Finding Nemo.  If you still have some excursion problems at very low frequencies, then you'll need to tune coffee can port lower with a longer port.  Your current banging problem is most likely with your current bottom driver and chamber, not the top, so the new big chamber should resolve it.

Bob,

You got the idea, but I think more exactly 7' 10.25" with top and bottom caps and using the current bottom cap as a brace and cutting a big hole for air flow.  You have room to lay it on it's side right?

I wouldn't even take the drivers out or disconnect them.

Maybe save the padding for another project, or leave it there.

We haven't talked about your mains.  Do they go low enough to work with a sub that only goes up to 40-50hz ?

82 dB sensitivity on the RL-S sucks hard.

Well, considering your 89 dB will get as loud with 300 watts, you should feel proud. lol.

I mean, full wattage the RL-S thing will ony go to 122 db. (without the box in the equation....)

Ok, John let me make sure I've got this correct.

-Build your idea as planned.

-Don't "SEAL" the double ports permenantly on the old HWK.

-You said; "Put them both behind you firing at each other and the ports firing into the corners resulting in some extra down low." --- You lost me there. "AT each other, but ports AWAY from each other?"

-Does the new box have the 3 ports just like Steves, or eliminate the doubles in the second build? The single center port would be 4" X about 17"?

I've modded this reply seven or eight times, got frustrated, removed it once, and started over.  >:(  Just when I think I've got it straight, and only have a couple questions .....  :o ? bla bla bla.


I THINK I'm with you John

Bob

[quote author=Bob  link=1145573673/75#75 date=1146779361]One driver in each box mounted with magnet in lower chamber, so "top" chamber now includes the center chamber also?

Continue running amp bridged with a "Y" in cable?
Or, run each sub on it's own channel? It might have some kind of neat stereo thing, or it might just sound funky running it that way.

Bob [/quote]

No, each box would have the driver mounted on one end and a port on the other end, no more chambers.  You'd just be able to easily convert it to the HWKenstein later.

Another alternative is to build HWKenstein exactly as described and leave the cap off of the original cab.  Give me a few days to crunch some numbers first and get port lengths for your different options and do some modelling to be sure they all make sense.  Plus I have another idea that I need to model first, and it might involve even less construction.

The bottom line is that you don't need different drivers or amp and you can put what you already constructed to good use.  At most all you need is some wood and port(s) and end up with impressive bass.  

Sometimes I forget and talk about what I would build for myself.  I already have plenty of subs to choose from and most have much more output than sane people would want.  I'm into this mode now where I want to outdo Dirt Dawg's Big Whistles and make my chair move with big LFE's.

Thanks John... "Gotta get back to burning CD's to bring with me to listen on Silver Iris OB-RLH's down at the beach."

Don't work too hard.  :)

Goal #1 this weekend, build a deck. (WAF ya' know....)
#2 tweek sub. (my play time  :()

I'm sure I can find a reason to "need" to go to Home Depot to get one more nail for the deck. A couple pieces of MDF and a lenth of 4" PVC may happen to fall into my truck, 'How'd that happen?'  (just in case HWK needs steroids. Can ALLWAYS use MDF.)

Thanks again, John

Bob

p.s.  John said, "I already have plenty of subs to choose from and most have much more output than sane people would want.  I'm into this mode now where I want to outdo Dirt Dawg's Big Whistles and make my chair move with big LFE's."

This is a good thing!

Hey BTW John, how do you keep your projector bulb from exploding with the LFE's?

Thats the movie we were seeing how much the big pair of SV subs could handle. we had to remove the wall lamps and stuff off the walls even before we turned the sunfire power subs loose.
felt like the carpet was rippling under our feet.
too bad it was my cousins system. Well maybe a good thing because my wife got pretty cranky during a couple cannon shots.
she was on the deck outside and I got a earful when we left.

LOL
Bob I am very interested in Johns mods as much as you, and rain is good news for both of us.
If you were closer I would  help ya so you could get to your sub. I like building decks No really!

Try the simple one first.  It may be enough.  You can't beat that size, but port noise is my concern as an ultimate solution.  Plus, you can squeeze in doing the new bottom port while she goes to the store.  Then after dark (can't build pretty decks in the dark), you can swap the driver over to the top and be testing Master&Commander that night.  The HWKenstein won't work with your current mains anyway and the single isobarik BR may be enough for now.  That way you'll have a better idea of what you ultimately want (more extension, more max output, etc).  Plus you can start tracking down your room rattles and get wifey used to the concept of high impact LFE's.

Oh, I almost forgot.  Stop banging that back plate on your drivers.  You have some good drivers and you don't want to mess them up.

Get one. well worth the money.
I have to sneak a replacement into the house for my old one.
great for balancing HT I use it at first then by ears

PJ noise is VERY tolerable. Almost not even there!  :)

You may have missed an earlier question I had John, Do you do anything special to isolate the PJ from the LFE?
I'm already getting a slight amount of "jitter" on the screen from the HWK during 'Darla and the cannons'. (worried about bulb failure)

Why is the meter so expensive there, is it the cost of the equipment, or shipping? If it's the cost of the item, let me know if I can ship you something?

A buddy has a Sony 'Commander' he lent me. It won't control the Sanyo PJ for some reason. I got frustrated and put it down a month ago or so. I'll pick it back up one of these days.

Bob

[quote author=Bob  link=1145573673/75#88 date=1147384299]PJ noise is VERY tolerable. Almost not even there!  :)
[/quote]

Ok, what is PJ noise?

Jason

Bob,

Shorten that mounting pipe for the projector, which will reduce the wiggles tremendously, or do you have a beam between the PJ and screen like I do which requires a low mount?  If nothing is in the way then getting it up high will have other benefits;  less shooting in the eyes, less heads blocking the image when someone gets up, brighter image because more light reflects down to the viewing area, brighter image because less light reflecting to the ceiling, less chance of someone bumping into the PJ, and best of all, a better picture because you'd use less keystone correction, which distorts the image somewhat.

Ahh...it now makes sense. Thanks.

What about movie theater style where it's in a seperate room, shining through plexiglass or glass? Or, just build a plexiglass box around it (with ventilation of course).

Jason

Shooting through a piece of glass will eat 6% of the light output and Bob is already giving up a lot more than that with the see-thru screen (I see your speakers now on the screen only pic).

Bob,
You can probably pick up some stability by bracing those supports up above the ceiling tile and maybe a glass right triangle brace on each of the 2 front supports.  It all looks kind of wiggley.  Paint the supports all the same color at your walls for the PJ floating in the air look (at least the pair in the front).

BTW, work was done early last night, so we watched Finding Nemo with the kids.  We did the Darla scene a few times and just running  a single 100L ported 12" Shiva that is tuned to 24hz, we were getting quite a nice effect and that's probably -12db or more in the teens where the tapping really hits.  It was enough to get a little eyeball jiggling, but not the strange chest compression like in a car.  

I really think the iso loaded Dayton 15's in the box you already have and the single port making it a low tuned BR should hold you over until you're ready to get radical.  Plus the finish work is already done.  A tube for a port, bolts to clamshell the drivers, a small piece of wood to block the 2nd port, and something to seal is all you need.  Worry about HWKenstein later.

The center could go behind the screen.  Just turn the volume up for it to match.  You can also mount the PJ upside down, which can shorten the mount length by 4" and make it that much more stable.

[quote author=Bob  link=1145573673/90#99 date=1147470770]Don't think flipping the PJ upside down will give anymore vertical hieght. The lens is placed directly in the center (top to bottom). [/quote]

You did need the weekend.  You mount the PJ to the bottom of that platform and shorten the supports for same overall height of lense, but shorter supports will be more stable.

BTW,  It's good to get away from the speakers behind the screen.

With a new screen, if you can lower the top of it, then you can raise the projector.

I want to see smileys on Monday.  Do that conversion on your HWK this weekend.