Well I I guess I will get my 5 messages in my own thread. From all the box calcs I could do today calls for a port the size of the top of the enclosure. I read some of the past constructions threads running into this same phenomenon. They had better sound with the top off the box. Did I screw up purchasing these plans?

Time will tell....

Drew up the plans and cut sheet.... 4.5 sheets of 1' mdf at around 130lbs a sheet.....?

This is not going to be portable that is for sure. Maybe doubling 1" is overkill. I seem to remember large rock bands having to use forklifts to move their speakers.

This current setup will weigh 720 lbs.. I may need to go back to the drawing board.

When it comes to building enclosures that most people would not dream of building you will find it hard to get replies.  I am not even sure what to tell you what will work and what will not with the HWK18.
Trial and error will be the only method to figure out the madness of HWK18 build but I bet you will be more than happy with the results.

Don't forget to post some pics.

HT-EXT

Amp is now on the way and speakers have been shipped. I made a pair of 5 way 15" speakers for my midrange. They do pretty good to about 55hz and then dont like much power. They will however drive a person out of the house. They are old school JBL d130's, I bought 3 of them for $50 at a yard sale. The same week I was given another jbl e130 in perfect shape. I have been busy.

Started on the box and it sure is heavy. Standing inside the speaker box is a strange feeling. My amp has still not shown up and the company is claiming the tracking number is messed up. The box is large enough that torsional loading starts to happen and I have to support it in sections. It should only be a full day of work until I can test the box and speakers, I will just have to use a smaller amp.

Once again I cannot attach pics and they are only 47k.

Nice work.

Well it sucks bad....however. I took the front lexan cover off the the top speaker and it came to life. It needs a port of 102 or 10"x10". I have to cover up the top speaker (so I dont drop something through the cone) and cut a new port on the top or make a death box style port. With the front top lexan off it is awesome and makes the 12"s sound like toys with no depth of field. I dont know if the bottom needs another port or not. Any ideas on determining this?

I have worked with allot of stereos and my 12"s have scared me before when they came on and I was half asleep. Today I was running the 18"s through there paces and turned my back on them. Dont turn your back on the 18"s in the house wrecker. The bass hit so hard I thought the box was falling on me....

I put a third port in the bottom and found that it made me lose 3-4 decibels in the bottom range and gain 3-4 in the 50hz+ plus range. No good, 2x22" 4" ports is all the bottom box needs any more than that and you lose bottom end. I will keep posting the experiments as I go.

I currently have a 112db at 25hz and I am running off of the 120 15 amp outlet. The amp is clipping and I have to keep an eye on it not to over heat the speakers. Some sustained spikes in the 125+ db in the 30-35hz range. This really gets the house shaking nice. It is really deep bass that sometimes will have some subharmonics that hit hard and make things fall off of the shelf.

Well.... I seem to have got something going with it. I kept my 8 cubic foot bottom, minus speaker and 22" of 4"abs ports. My upper 8 cubic feet minus  port volume of 24 3/4"wide x 4"high x 29"long. My center chamber is large enough but not critical. From 25hz to 85hz I am getting a 9db variation. With the gain turned up I am hitting 125-126 decibels all over that range and am right at the limits of my household wiring. I am popping the breaker box with extended run time. I can push 122db almost continuous. I am sure that with the wiring done and running my second amp I can push 130db at 45hz.

What is really nice about running center fire and 2 different ports is that you have different ranges that might conflict somewhat but begin to reinforce the harmonics of the building. In other words you get some huge rumble. My wife  could feel the bass in her chair watching tv in the next door neighbors house, not to mention they live 2 houses over and there windows where rattling to pieces.

I cant stress enough the need for a decibel meter. It is to easy to do something and not make an improvement and think that you did. I tested top and bottom speakers separately and combined using multiple variations of port size and number of ports. I really think that this is it and trying to get more output through dimensional changes would really sacrifice transition and balance.

Lining half the bottom chamber with foam got me 2db at 45hz and 3db at 50hz. The upper chamber it gained me 2-5 db. 2db from 30-60 and then went higher all the way up to 5db gain at 70hz. The upper box could have been bigger but I would have run into needing 3 sheets of 1"mdf for very little gain.

I have to go back in and radius some corners and glue the whole upper port together now that I know this design is a keeper. I need to finish beveling the edges of the center chamber which will stay open and mount my Lexan viewing port below the center chamber. Another days work ahead.

Well 2nd Crown xls 5000 hardwired in and I am no longer popping breakers. I think I may have come to the end of conventional exploring. Any questions feel free to ask them.

I have not reached 140 db as far as I know. I have pegged my meter and I am clipping both amps on 30 amp breakers and 12/2 wiring running directly to the amps and only them. I have to go larger wire to the speakers or double up my existing.

The local audio guys have been driving past me trying to show off their bass. I guess when they drive by the house when I am 80 yards from the road and their mirrors rattle they get impressed(or they hear the bass over their own).

I do have to say that the bass level are dangerous. Please resist the urge to stick your head in the center chamber, I tried it and my left eye wanted to pop out of my head and felt like it was going to. This is not something I would want to explain to my wife. Also 125+ dbs of 35hz and below causes all sorts of strange energy in the body. I felt levels of euphoria mixed with panic and pain all mixed together. It definitely hurts the ears, I mean it causes pain and I have to plug them when doing long exposure tests.

In order to go louder and deeper the box will need to be bigger and enclose better speakers and 220 volt amps running 7000 watts will be needed. I would have had to pay at least a $1000 a speaker to get more wattage and power output. And then my amps would not be enough. My pockets are not that deep so I will let the next guy do it, unless I win the lottery, or they go on sale For now my home 12,000 watt entertainment center is done

Jeremy, This is insane! You are my new hero. I say go for broke and build a second copy. If one is too much, two must be even better. I need a Housewrecker because I hate my neighbors, that would teach them to not build a house across the road from a madman.
Cudos!!

Greetings
Just wondering how your HW played out for you and what you settled on after tweaks and mods.
I have built a couple of the Decware subs in the past.
Just curious how things turned out for you on this monster. Someone approached me to build a HT sub to fill a large room and I was going to go with a horn but this 18HW might fit the bill and use up less room.
I have always wanted to built a HW this big

All the best,
Gex