Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 181 Old 11-20-09, 07:52 PM Thread Starter
Senior Shackster
 
Mike Cason's Avatar
Mfishmike
 
Join Date: Mar 2007
Location: Philippines
Posts: 565
Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

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/foru...#ixzz0XWvNWnLo

If it is too loud, then you may be too old!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Mike Cason is offline  
Sponsored Links
Advertisement
 
post #2 of 181 Old 11-20-09, 09:09 PM
Elite Shackster
 
Mike P.'s Avatar
Mike
 
Join Date: Apr 2007
Location: Chitek Lake, Sask.
Posts: 19,397
re: Maelstrom 21" With 6 1800 Gram 15" Passive Radiators

1.25" MDF, it's gonna be a monster! With 2 A.E. 18" passive radiators on each side this is going to be a first as far as I know. Looking forward to this build.




We're all in this together!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Mike P. is offline  
post #3 of 181 Old 11-20-09, 11:00 PM
Shackster
Colby
 
Join Date: Oct 2009
Location: Thunder Bay
Posts: 61
re: Maelstrom 21" With 6 1800 Gram 15" Passive Radiators

I like where this is going. Can you say heavy?
ridecolby is offline  
 
post #4 of 181 Old 11-21-09, 07:10 AM Thread Starter
Senior Shackster
 
Mike Cason's Avatar
Mfishmike
 
Join Date: Mar 2007
Location: Philippines
Posts: 565
re: Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

Mike, it's nice to be the first with a successful build. I usually don't copy others because I don't feel that it was my build and that takes away a little from the fun of it all.

As far as being heavy, it's going to be like building a tilt wall concrete building and then moving it! With a subwoofer driver like the Maelstrom 21 and all of the passives working together, I want a solid cabinet which will be resonant free. It is going to be tough to work with during the build. My two stacked subs in my avatar weight 235 lbs. ea.

If it is too loud, then you may be too old!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Mike Cason is offline  
post #5 of 181 Old 11-21-09, 12:36 PM
Pending
Kevin
 
Join Date: Nov 2007
Location: Port Angeles, WA
Posts: 1,026
re: Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

This is about what you can expect with that enclosure Mike. I stuck a 13Hz subsonic filter on this, figured 20% fill and used 2000W with this simulation. I used my PR-15"s because I was too lazy to load the exact parameters for John's PRs but they should be roughly the same.

Even with 2000W (EP-2500 type amp) you have plenty of safety margin. The PRs are < 40mm P-P so they should be alright using six of them. I wouldn't worry about the main driver excursion @ 10Hz, simply because there isn't much down there and the rest of your system probably has DC blocking filters cascaded, which attenuate down there anyway. Depending on your room, I'd say you have very respectable output @ 15Hz and above.



Kevin Haskins
Exodus Audio
Kevin Haskins is offline  
post #6 of 181 Old 11-21-09, 01:00 PM
Senior Shackster
 
dyohn's Avatar
David
 
Join Date: Apr 2008
Location: Valley of the Sun
Posts: 704
re: Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

125dbSPL @ 20Hz?

Last edited by dyohn; 11-21-09 at 02:41 PM.
dyohn is offline  
post #7 of 181 Old 11-21-09, 01:06 PM
Pending
Regnar
 
Join Date: Oct 2009
Posts: 18
re: Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

Look forward to the build. When ever someone breaks out a pair dial calipers to measure MDF must have some precision in mind
Regnar2 is offline  
post #8 of 181 Old 11-21-09, 01:19 PM Thread Starter
Senior Shackster
 
Mike Cason's Avatar
Mfishmike
 
Join Date: Mar 2007
Location: Philippines
Posts: 565
re: Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

Thanks for the very nice graph and modeling work Kevin! I've only got the QSC 1450 amps I've been using for my current subs, so it looks like I'll be upgrading the amp as well. I don't like the term clipping, and with the 1500 watt rating of the Maelstrom, my 1450s briged will only put out 1400 watts; 4 ohms at 1khz. Bring the sub output level down to the high teens or low twenties, and the amp's output will probably be down around 900 to 1000 watts maxed out and will probably clip.

John's 18" flat mdf passives I think have an fs of 3.9 at 2100 grams. 3" P-P on cone travel.

I appreciate your excellent communications, the phone call, and your service beyond what is expected out of a dealer.

VBR
Mike

Quote:
Kevin Haskins wrote: View Post
This is about what you can expect with that enclosure Mike. I stuck a 13Hz subsonic filter on this, figured 20% fill and used 2000W with this simulation. I used my PR-15"s because I was too lazy to load the exact parameters for John's PRs but they should be roughly the same.

Even with 2000W (EP-2500 type amp) you have plenty of safety margin. The PRs are < 40mm P-P so they should be alright using six of them. I wouldn't worry about the main driver excursion @ 10Hz, simply because there isn't much down there and the rest of your system probably has DC blocking filters cascaded, which attenuate down there anyway. Depending on your room, I'd say you have very respectable output @ 15Hz and above.



Kevin Haskins
Exodus Audio

If it is too loud, then you may be too old!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Mike Cason is offline  
post #9 of 181 Old 11-21-09, 01:25 PM
Pending
Kevin
 
Join Date: Nov 2007
Location: Port Angeles, WA
Posts: 1,026
re: Maelstrom 21" With 4 - 2100 Gram 18" Passive Radiators

Quote:
Mike Cason wrote: View Post
Thanks for the very nice graph and modeling work Kevin! I've only got the QSC 1450 amps I've been using for my current subs, so it looks like I'll be upgrading the amp as well. I don't like the term clipping, and with the 1500 rating of the Maelstrom, my 1450s briged will only put out 1400 watts; 4 ohms at 1khz. Bring the sub output level down to the high teens or low twenties, and the amp's output will probably be down around 900 to 1000 watts maxed out and will probably clip.

I appreciate your excellent communications, the phone call, and your service beyond what is expected out of a dealer.

VBR
Mike
Hey... no problem. I love getting people pointed in the right direction. You can use as much power as you can afford on this driver. I have several people using 3000-5000W worth of amplifier (ratings) and there is not an issue with using "too much" power. They eat it up.... and what you get out of the wall usually limits what you put into the driver anyway.

Kevin Haskins
Exodus Audio
Kevin Haskins is offline  
post #10 of 181 Old 11-22-09, 07:44 PM Thread Starter
Senior Shackster
 
Mike Cason's Avatar
Mfishmike
 
Join Date: Mar 2007
Location: Philippines
Posts: 565
Re: Maelstrom 21" Beginning build pics....

My wife got home and thought I was building a coffin to save money. I had to remind her that mdf wouldn't last very long buried.....

Well, here are the first pics.....many more to come.

I'm really not sure how I am going to be able to work with this heavy of a cabinet during construction, but that's never stopped me before. This material is so thick I used 2.5" decking screws and filled up the holes. They will be sanded and I will laminate the entire cabinet. This is just too heavy for a glue up construction project and there will be a lot of internal pressure. I did use generous amounts of glue too.

If it is too loud, then you may be too old!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Mike Cason is offline  
Reply

Bookmarks

Tags
maelstrom-21" , passive radiator

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome