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Discussion Starter · #1 ·
Is it possible? I got swallowed up by the new fad a while back, but I am only concerned with 35Hz on down. I know these tapped horns are amazing, but I don't like how they perform better as you get higher in the FR. If I build one large enough to go low enough, this might just be my thing. Otherwise, I am still looking at dual 21's in 128 cubic feet each, 16" port each, 10Hz-15Hz tune. The portion of the room I'll be placing them in is over 8' x 12' in a 4' section... actually a little over 6" play in each direction. Is that big enough to be able to implement such a driver with such a bandwidth?
 

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Is it possible? I got swallowed up by the new fad a while back, but I am only concerned with 35Hz on down. I know these tapped horns are amazing, but I don't like how they perform better as you get higher in the FR. If I build one large enough to go low enough, this might just be my thing. Otherwise, I am still looking at dual 21's in 128 cubic feet each, 16" port each, 10Hz-15Hz tune. The portion of the room I'll be placing them in is over 8' x 12' in a 4' section... actually a little over 6" play in each direction. Is that big enough to be able to implement such a driver with such a bandwidth?
To be honest a well built horn sub is probably going to smash any other type of sub given the proper driver and space. This is a real theater type of sub(jet plane kind of output). However the size of a horn for the 21" Maelstrom if it's even suitable for such a build is going to be something very large. I see no reason to do such a build since even a horn loaded shiva will easily fill your room.

I doubt a 21" Maelstrom horn has any practicality in a home.
 

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Discussion Starter · #3 ·
To be honest a well built horn sub is probably going to smash any other type of sub given the proper driver and space. This is a real theater type of sub(jet plane kind of output). However the size of a horn for the 21" Maelstrom if it's even suitable for such a build is going to be something very large. I see no reason to do such a build since even a horn loaded shiva will easily fill your room.

I doubt a 21" Maelstrom horn has any practicality in a home.
I have an IB3 18" got it for $240 shipped. 4 of them are $800. A single MX 21 is $650. Practical isn't what I'm aiming for :)

dual 128 cubic foot boxes when 30 cubes each would be plenty.... not goin for practical.

I used to rent but I bought this house specifically to build this. If I wasn't into audio, I'd drive a small 4 cylinder 2 door car, but I got an ugly Aztek to put a 22 cubic foot box with a single 18" sub in it. Dumb? yes. I like it.
 

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Ryan, I may have made a mistake by presenting these photos to you. During the many years of speakerbuilding, I've collected some interesting photos of some unusual builds. After reading your post, and now that you own the home, you may want to break out your foundation and build a "Real Subwoofer". Check out this transmission type in the floor subwoofer. I beleive it has 8 large subwoofers in the driver panel. Just when you thought it couldn't get any bigger....
 

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Oh Mike I think with Ryan you really messed up showing him this. All kidding aside Ryan have you looked at the modeling programs for horns and seen what you can come up with? I bet you would have to have a room as big as the one your listening in for the horn alone. If I get the itch one day I would like to build one myself. I think it would be a cool project. Good luck on the new build.
 

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Oh Mike I think with Ryan you really messed up showing him this.
Yea...He did open the door by saying he wasn't trying to be practical!

I forgot to post that if memory serves me correctly, this floor sub is ported out just in front of the stage/theater and has a left and right configuration with 8 massive pro drivers for each side.

It's always nice to see how "normal" we really are after looking at builds like this one....tehehe....:dumbcrazy:
 

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Discussion Starter · #7 ·
Ryan, I may have made a mistake by presenting these photos to you. During the many years of speakerbuilding, I've collected some interesting photos of some unusual builds. After reading your post, and now that you own the home, you may want to break out your foundation and build a "Real Subwoofer". Check out this transmission type in the floor subwoofer. I beleive it has 8 large subwoofers in the driver panel. Just when you thought it couldn't get any bigger....
:-D over the last 6 or so years I have re-visited that build... I love it! I wish it were tapped or somehow implemented the rear wave but what was that thing, 110dB @ 20Hz 1 watt or something crazy? Before I finalized closing on this house I considered all kinds of crazy things including removing 1 of the bedroom floors for the biggest horn mouth I've ever seen...
 

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Discussion Starter · #8 ·
Oh Mike I think with Ryan you really messed up showing him this. All kidding aside Ryan have you looked at the modeling programs for horns and seen what you can come up with? I bet you would have to have a room as big as the one your listening in for the horn alone. If I get the itch one day I would like to build one myself. I think it would be a cool project. Good luck on the new build.
you said it! I've been watching these horns closely, just as I've watched these great drivers come out... I just cant choose so I want to mix them... take up a whole room to tap horn an MX21 if I have to!
 

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Ryan,

You have posted on my Mael 21 build thread.

http://www.hometheatershack.com/for...trom-21-4-2100-gram-18-passive-radiators.html

I'm tuned to 15hz, have a 23" x 23" x 62"h footprint sporting 13 cubes. This subwoofer goes incredibly low, especially with the LFE in the movies. I'm pumping it with the Face Audio TS1200 amp bridged to mono at 2719 watts. With the 1.25" mdf, I hear no resonance. Check out my final pics on the last post.

I sold my dual stacked Soundsplinter subwoofers to a fellow in Peroria Illinois, but he lost his job just after Christmas. He has them listed here at:

http://www.hometheatershack.com/for...nter-rlp-15-d2-8-ae-15-passive-radiators.html

He really needs the money and wants to sell them fast, so you might get him to remove all of the drivers and passives and ship them to you and he can discard the cabinets and grills. It's a shame because they are awesome sounding subs. You get 8 - 15" 1800 gram flat mdf passive radiators (the best) with a low fs of around 3.9 from AE Speakers, and 4 of the Sound Splinter RLP-D2 15s you could sell or use later.

Just a thought.....

I couldn't ask for a better subwoofer with my new build; without question!

Good luck,
Mike

You could do some modeling and I think that four of the 15" 1800 gram passives and the Mael-X would be an excellent combo and get you way down low in the box tuning frequency and give you more floor space in your L/R or HT.
 

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I've never done PR... like horns, I am cautious about taking the dip!
Me either, until I built my first one.....I've been hooked on them every since even though the build is more expensive.

I have a saying I learned from a very successful business person:

"If you don't swing at the ball, you won't hit it".

Mike P. or Kevin may be able to do some modeling for you....

Take the driver(s) parameters and the passive radiators' parameters, then decide what box tuning frequency you want. The fourth and final part of the equation will be figured in your net volume required for the enclosure by the software program. It's fairly straight forward and I've found it to be within 1 hz of the modeled sub. Mine modeled out at 15.5 hz and after completing the build, using Linkwitz's test tone CD, I'm at 15hz tuning. Add a dash of room gain with proper sub placement, and hold on! 118 to 120 dB @ 20hz is not too shabby.

In my case, the 13 cu ft worked out very well for me. Using the 15"ers, you may need more cabinet volume or more passives to get a lower tuning frequency depending on what and how many drivers you will be using. No port noise, no chuffing, no port resonance.....

I've come to realize that one of these Mael 21s is almost too much. L/R is 20' x 25' x 9' ceilings opening up to the kitchen bar and dining area.

I really wish folks riding the fence on the PR designs could have the opportunity to sit in on one of my auditions. Their smooth, low, but yet well defined bass is awesome. It's a deal maker, not a deal breaker.....

Good luck with what ever you build Ryan,

Mike
 

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Discussion Starter · #14 · (Edited)
You get 8 - 15" 1800 gram flat mdf passive radiators (the best) with a low fs of around 3.9 from AE Speakers
I'm only seeing the Passive Radiators PR18-1600 on the website

Standard units come with 1600gram Mms and have the following parameters. Custom massed units can also be ordered.

Fs: 4 Hz
Qms: 85
Vas: 1840 L
Mms: 1600 g
Sd: 1200 sq cm
Vd: 9 L
Xmax: 3" p-p

PR18-1600 Highlights:
Soft compliance for optimal performance
Capable of moving nearly 9L of air
Cast aluminum frame
Can be custom massed for any desired tuning


MDF! wow! Jus saw a pic from one of your threads!
 

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Discussion Starter · #15 ·


ok then here we go! I used those 18's... you done it man.. made me ____ or get off the pot... I gotta go to work soon but I'll play a few minutes before I go... if I fall in love with these, I may do them in the van too!
 

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Ryan,

Don't throw your money away to get them specially massed for you. I never buy a preloaded passive. It's worth my time to add mass unless there is a special deal going on.

You know they are already 1600 grams so you need 500 more. (18" PRs) I've included a couple of pics of my loading. The last pic is while they were in the house overnight curing. Round up several large washers from your hardware store to obtain the extra 500 grams. I have a chemists scale, but you can figure out something. I bought a full box of washers and it was cheaper with just a few left. I would get some thinner washers to get the exact weight as noticed in pic #2. These are the 15" 1050 gram passives I loaded to 1800, but the same mass loading principle applies for the 18" passives as well.

Purchase one container of Devcon two part epoxy per passive radiator. Use the container to mix it up very well and then at the same time without stopping, pour a small amount around the center of the passive where the first washer will rest; continue pouring and drop in a large washer and pour another bead of epoxy on the top of that washer in a circular motion. Keep the pour continuous as it is easier to get an even amount on all of them without wasting any epoxy. Drop in the next washer until you have them all in the passives.

Have the passive sitting where they will be flat for the night and center the washers and also press down on them with a small stick. Once they are centered, leave them alone. I gaurantee they will never come loose on you.

You won't be disappointed! Sure the passive radiator has a quicker rolloff on the low end, but when you are tuned down to 15hz or lower, who cares! LFE effects are unaffected, play extremely low and with authority, and these are also extremely musical. Not much esle one can ask for out of a great subwoofer. I hear -0- distortion with my new build.

Hey, I just noticed that your thread made my 400th post here at the forums! That means you are required to pay for a trip for my family to the Carribean for a week, all expenses included....
 

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I'm tuned to 15hz, have a 23" x 23" x 62"h footprint sporting 13 cubes. This subwoofer goes incredibly low, especially with the LFE in the movies. I'm pumping it with the Face Audio TS1200 amp bridged to mono at 2719 watts. With the 1.25" mdf, I hear no resonance.
I'm just doing the math here, but how did you lose more than 5 cubes to port and bracing!?
 

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I'm just doing the math here, but how did you lose more than 5 cubes to port and bracing!?
I added a 3/4 birch plywood bottom with 3/4" runners for feet to get my 62". Using the calculator
http://www.hometheatershack.com/forums/enclosure-volume-calculator/ I came up with 14.227 cu. ft with an actual cabinet height of 61" (23 x 23 x 62 is the finished product.) I estimated with my internal bracing and driver displacement that would compensate for the 1.227 cu. ft. difference, not 5 cubes; which for build purposes, is very close. The 1.25" thick braces do displace a lot of cu in.
 

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Discussion Starter · #19 ·
Ryan,

Don't throw your money away to get them specially massed for you. I never buy a preloaded passive. It's worth my time to add mass unless there is a special deal going on.

You know they are already 1600 grams so you need 500 more. I've included a couple of pics of my loading. The last pic is while they were in the house overnight curing. Round up several large washers from your hardware store to obtain the extra 500 grams. I have a chemists scale, but you can figure out something. I bought a full box of washers and it was cheaper with just a few left. I would get some thinner washers to get the exact weight as noticed in pic #2. These are the 15" 1050 gram passives I loaded to 1800, but the same mass loading principle applies for the 1800 gram units as well.

Purchase one container of Devcon two part epoxy per passive radiator. Use the container to mix it up very well and then at the same time without stopping, pour a small amount around the center of the passive where the first washer will rest; continue pouring and drop in a large washer and pour another bead of epoxy on the top of that washer in a circular motion. Keep the pour continuous as it is easier to get an even amount on all of them without wasting any epoxy. Drop in the next washer until you have them all in the passives.

Have the passive sitting where they will be flat for the night and center the washers and also press down on them with a small stick. Once they are centered, leave them alone. I gaurantee they will never come loose on you.

You won't be disappointed! Sure the passive radiator has a quicker rolloff on the low end, but when you are tuned down to 15hz or lower, who cares! LFE effects are unaffected, play extremely low and with authority, and these are also extremely musical. Not much esle one can ask for out of a great subwoofer. I hear -0- distortion with my new build.

Hey, I just noticed that your thread made my 400th post here at the forums! That means you are required to pay for a trip for my family to the Carribean for a week, all expenses included....
sounds like I could have a lot of work cut out for me... but I may be interested in those 8 15's... I just needed some numbers to punch in quick to get my very 1st PR plot running. All that mass... doesn't that kill efficiency? I guess no... just lowers the fequency it will move the most at (Fs) but will move just as much... but still...

And those PR cones are 3/4" MDF?!?!?!?!?!
 

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Ryan, I've never considered an audio project for myself work...that's a dirty word. I call it a challenge cause I know what I hope to expect and enjoy every moment in the shop until my projects get rolled into the home.

I don't know if you read my post, but those are the same type that Dan Wiggins of the old Adire Audio & Stryke Audio days were selling. They were, and still are, IMHO the best passives around. To add to that, having a 3" point to point excursion allows them to work without losing them. I've never had to push them that hard. These have such a low fs to boot. You ought to gobble up my lead to my old subs and strike up a deal and get four extra RLP 15" drivers for almost pennies. I'm surprised they aren't gone yet!

If you do get those 8 15s, I have them loaded to 1800 grams, their maximum suggested mms from 1050 grams initially. The ones in the photos I posted for you are the same ones that are for sale.

Losing efficiency?....not a chance. Increasing envy with your buddies, a given.....making points with your wife, TBD......
 
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