Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

57957 Views 180 Replies 23 Participants Last post by Mike Cason, Jun 1, 2010

Mike Cason

Discussion Starter · Nov 21, 2009

Here is my build thread for the Maelstrom 21. I'll try to provide enough quality pics during my build for you.

I'm using Kevin's Maelstrom 21"er with the passive radiator design. I normally don't like building a passive radiator sub with a Qts over .4, but it is so close, I won't have a problem.

Here's the deal....23" x 23" x 60"; 13 cubes and 15.5 hz box tuning. With the typical passive radiator design there is more of a roll off but at this already low box tuning, I'll have more than plenty of bass. I needed the height to match my main speaker's height and get the cabinet volume I need. Better WAF here.

I just picked up the pallet of materials from my mill. My construction material is 1.25" mdf. It looked like I had ten bags of concrete in my truck going down the road. In the roll of plastic, I've got two sheets of Pionite black slate laminate to match all of my other speakers.

Cabinet resonance with this thick material; I don't think so. Moving it? Now that's another challenge.

Just got back from Houston with the materials so here is the first build pic:

Read more: So where are the Maelstrom-X 21" Build Threads! - Home Theater Systems - Electronics and Forum - HomeTheaterShack http://www.hometheatershack.com/for...elstrom-x-21-build-threads.html#ixzz0XWvNWnLo

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Mike Cason

Discussion Starter · #101 · Dec 13, 2009

Here it is Mike....

I still had a spot or two on the camera lens. The grills I'm making won't be full length like the mains to break up the looks a bit. To get a prospective on the driver sizes; the mains have 12" Lambda woofers and 15" passive radiators; and the sub has 18" passives with the sweet 21.

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Mike P.

· #102 · Dec 13, 2009

Looks good, the sub blends in nicely with the mains. I can imagine the output after the sub and PR's loosen up a bit. It should be an experience! :hsd:

Mike Cason

Discussion Starter · #103 · Dec 13, 2009

Mike P. said:
Looks good, the sub blends in nicely with the mains. I can imagine the output after the sub and PR's loosen up a bit. It should be an experience! :hsd:

Thank you Mike....:wave:

They are improving by each day.

I was going to run some pink noise through them for a couple of days while I was out, but decided to burn them in during normal playback. As you know, I was going to part out and sell the drivers out of my other two subs in my avatar, but I sold the pair to some Shacksters in Illinois. Here's the report I got back from them this morning about them. I can't stress enough the quality of the bass you get out of a good passive radiator design. I'm so glad they went to a good home instead of being parted out. I was able to step up to the 4 - 18" 2100 gram passives too:

That 21 is looking nice! I have been following it on the SHACK. Bravo on another amazing build. That 21 looks intimidating!

I have gotten the subs integrated as of last night. I updated the firmware on my Velodyne SMS-1 which allowed me to set my subsonic filter even lower than 15Hz. I have usable output to 12Hz! I have been listening to music at moderate levels and am loving it. I watched a blu-ray concert last night in Dolby True-HD and was all smiles!

I found that the subs have so much clean output that I continue to turn the volume up until the levels are insane. I recently had my neighbors complain of things shaking in their house. They are over 300 feet away from the subs! My house does not like the new found power, judging by the groans and oscillating walls, but that is too bad.

I am a movie buff too, and the LFE on my favorite movies is superb.

I just wanted to tell you how much I am enjoying the subs. They are excellent!

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favelle

· #104 · Dec 14, 2009

Holy , that's crazy!

Lonely Raven

· #105 · Dec 14, 2009

Looks fantastic Mike!

So, I'm guessing you have some issues with those large reflective surfaces at the front of the room...and I'm not seeing any room treatment in there. How do you deal with all that? I can barely stand it in my theater/living room and I've got a huge super-chunk with more absorption on the way.

Mike Cason

Discussion Starter · #106 · Dec 14, 2009

Lonely Raven said:
Looks fantastic Mike!

So, I'm guessing you have some issues with those large reflective surfaces at the front of the room...and I'm not seeing any room treatment in there. How do you deal with all that? I can barely stand it in my theater/living room and I've got a huge super-chunk with more absorption on the way.

Well Raven, you know I build a much better speaker than you do! Mine don't need a doctor and special treatment!! :devil:

I really don't have any issues. I do have a lot of reflective walls for sure. The reason we don't have room treatment is now handed over to the wife for the blame. We built our new home ourselves. It was a 3 year project. She wouldn't make or buy the drapes until we got rid of our well used sofas. "Color co-ordination" she said. We do have very thick pile carpet and padding with throw large rugs that help.

Well, I made a grueling non stop trip to some remote spot in Alabama and bought the 6 Lazy Boy recliners from Sonnie and now she has the color she can use for the drapes. Any neutral color would have worked for me. So now, I'm waiting on the economy to pick up so we can work again and get the drapes up. That's all I'm going to do for treatment because we still want our living room and not a room with bass traps or foam panels stuck in the corners and on the walls. In a dedicated HT room, you betcha!

Check the reviews on the Houston DIY Group thread and you will hear rave reviews about the sound quality it has as it is.

The system sounds fantastic as it is and we can listen to it for hours at high levels withought fatigue, so that is the most important thing to us.

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sub_junkie

· #107 · Dec 15, 2009

Mike Cason said:
I'm proud of you for taking up this hobby son. There are so many other 15 year old's out there taking on hobbies that lead them down the wrong road. You are in a forum with a bunch of great guys and we'll support you all that we can.

Mike

Definitely well said, and thanks. :T
The bold part is exactly right. Teens get involved in skate boarding and a lot of other things, then get into drugs, and it all goes downhill from there. Its actually happened to two of my old best friends that were 13 and 16. Sad stuff.

I can say that I am enjoying my music more now, although my mom might not be, especially on slowed down songs lol. :bigsmile:
I try to keep the bass turned down for her, but my dad doesn't really care.

Are you by any chance going to get some vids of the passives and the sub playing some bass heavy songs, Mike? I've never really seen a video with passives bigger than a 10" IIRC. Nice mains also by the way. I bet they can crank out the sound.

Mike Cason

Discussion Starter · #108 · Dec 15, 2009

Well, I was a bad dad because I didn't allow skateboarding.....He never had a head split open either.....
We did a lot of other things that made up for it.

No, I don't plan on making any vids. I've got too much else to do to this time of the year.

I hit the system with the 1812 Overture this morning after I was told the cannon shots were 10 hz and wouldn't play them and would probably destroy my driver. After I played it once, I replayed it again at high SPL and no strain on this ole sub. She performed well. :rofl2: I did look across the room for the cannon ball hole~~~~

I checked out your build. Lots of work and I bet you have great bass. Keep up the good work! :bigsmile:

My mains have a pair of the Lambda TD12s midwoofers paralleld that can handle 500 watts each and I've got them crossed over at 700 hz, so they can speak loudly when needed. The Lambdas have a great motor design and build. Many a fine artists have played their concerts through them and they seem to get sweeter by the day.

Cheers

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robbo266317

· #109 · Dec 15, 2009

If you have the Telarc recording of the 1812 it contains 3Hz fundamentals....

Mike Cason

Discussion Starter · #110 · Dec 15, 2009

robbo266317 said:
If you have the Telarc recording of the 1812 it contains 3Hz fundamentals....

Woooo..got to get it....got to get it.....I saw it on Amazon but am not buying anything until work and business picks up. It was neet to hear it even at the 10 hz though. Thanks for the tip robbo266317 :bigsmile:

Lonely Raven

· #111 · Dec 16, 2009

sub_junkie said:
Definitely well said, and thanks. :T
The bold part is exactly right. Teens get involved in skate boarding and a lot of other things, then get into drugs, and it all goes downhill from there. Its actually happened to two of my old best friends that were 13 and 16. Sad stuff.

I can say that I am enjoying my music more now, although my mom might not be, especially on slowed down songs lol. :bigsmile:
I try to keep the bass turned down for her, but my dad doesn't really care.

Are you by any chance going to get some vids of the passives and the sub playing some bass heavy songs, Mike? I've never really seen a video with passives bigger than a 10" IIRC. Nice mains also by the way. I bet they can crank out the sound.

Well I see who wears the pants in this household. :whistling:

sub_junkie

· #112 · Dec 16, 2009

Lonely Raven said:
Well I see who wears the pants in this household. :whistling:

Haha, on certain things yes (like school :rolleyesno:. I'm homeschooled, and it's a much better education), and on other things no...
My dad usually just chills in his garage working on R/C Cars until my next race lol. I would wrench on them, but he's better at it. :T

I recently found out that I can move quite a bit of air through my door on Bass I Love You with the HPF turned off and the sub near Xmax. It will move by shorts around quite a bit. I guess that's pretty good for HT? considering its a much bigger space than car stuff.

Sonnie

· #113 · Dec 17, 2009

What's with you Mike... you only built one of these? You need a at least a pair in your room... :dontknow:

Very nice work!

Mike Cason

Discussion Starter · #114 · Dec 17, 2009

Sonnie said:
What's with you Mike... you only built one of these? You need a at least a pair in your room... :dontknow:

Very nice work!

Thanks but I just listed it for sale in the classifieds.

UPDATE: I can't let go of this one....I'm pulling it off the market. It gets better by the day!

Sonnie, thanks for the suggestion but one more will destroy my home!....:T

Mike

Lonely Raven

· #115 · Dec 18, 2009

Ahhh, crumbs. I'm sorry to hear that.

I'm teetering on that same abyss as well. For this month at least.

Mike Cason

Discussion Starter · #116 · Dec 18, 2009

Lonely Raven said:
Ahhh, crumbs. I'm sorry to hear that.

I'm teetering on that same abyss as well. For this month at least.

As Dave Ramsey calls it, "beans & rice" time.....

sub_crazy

· #117 · Dec 18, 2009

Good luck to you Mike, in fact good luck to us all as these times are worse than I can ever remember.

What kind of passive radiators are you bringing in?

lsiberian

· #118 · Dec 18, 2009

Mike Cason said:
Thanks but I just listed it for sale in the classifieds. My work stopped and accounts receivables aren't coming in. :spend:

We're both out of work right now. :sweat:

Sonnie, thanks for the enthusiasm....:T

Mike

That stinks buddy. I have hope that things will improve soon. But it's not easy at the moment.

Mike Cason

Discussion Starter · #119 · Dec 18, 2009

sub_crazy said:
Good luck to you Mike, in fact good luck to us all as these times are worse than I can ever remember.

What kind of passive radiators are you bringing in?

Peerless Tymphany quit building the 830880 5.25" truncated passives with an fs of 23 hz. I use them in my Bang and Olufsen Redline RL60 modification and one of the owners of their Redlines said they were no longer available. I spent two years and a lot of money buying up used Redline speakers to help folks rebuild their Redlines, and I designed a replacement passive radiator system for the failed ABR plates the engineers used. Without these passives, two years of my work would have been for nothing. I had to pay for re tooling from Tymphany and had to buy a mininum of 1000 of them to keep my Redline modifications availble to folks. They are an excellent product and I've got a lot of information on my website about both the Tymphany passives and the Bang and Olufsen Redlines with a pictorial step by step on "how to" rebuild their faild ABRs. I paid more money today to LA customs and they will be here by rail on the 29th, even though I have purchased almost two hundred of them already from other distrubtors who dropped them.

This is a tough business and it takes a lot of capital to keep it going. I only make a few bucks on each of them so it's going to take a couple of years or so to break even, if I can manage to even do that.

They are excellent for many other applications and you can build deeper sounding bass in smaller cabinets with smaller drivers. Their use is endless. Computer speakers, boomboxes, Ipod speakers, mains, surrounds, and so on.

Mike

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sub_junkie

· #120 · Dec 18, 2009 (Edited)

Mike, I'm sorry to hear that your having to sell your awesome sub. These are definitely hard times, although they could be handled better by the president.

Just out of curiosity, how much did you list your sub for in the classifieds?

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