Very low budget sub. - Page 3 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #21 of 54 Old 02-01-07, 12:51 PM Thread Starter
Senior Shackster
Mike
 
Join Date: Jan 2007
Location: Chattanooga, TN
Posts: 292
Re: Very low budget sub.

What about, instead of using a port, I put this in there? That could probably cut down on the size of the enclosure and boost the low end some. Suggestions? Remember, I'm still a newbie at this.
mgboy is offline  
Sponsored Links
Advertisement
 
post #22 of 54 Old 02-01-07, 12:58 PM
Senior Shackster
 
BoomieMCT's Avatar
Boom
 
Join Date: Dec 2006
Location: Fairfax, Va
Posts: 866
Re: Very low budget sub.

Quote:
mgboy wrote: View Post
What about, instead of using a port, I put this in there? That could probably cut down on the size of the enclosure and boost the low end some. Suggestions? Remember, I'm still a newbie at this.
That 12" Dayton PR has an xmax of 10mm. I've always heard you want the volume the PR moves to be 150% - 200% what the driver moves so you'd need at least two. After that, it basically acts like a ported enclosure which means if you were hitting overexcursion in a 8 cubic foot ported box, you will also hit overexcursion in an 8 cubic foot PR box.

But, yes, with a smaller box this should work and be interesting.

EDIT - BTW, please note that PR's can not be downward firing.
BoomieMCT is offline  
post #23 of 54 Old 02-01-07, 01:01 PM Thread Starter
Senior Shackster
Mike
 
Join Date: Jan 2007
Location: Chattanooga, TN
Posts: 292
Re: Very low budget sub.

So If I got two of those, get the enclosure size down to day, 5 c.u. ft, How well should/would it perform do you reckon?
mgboy is offline  
 
post #24 of 54 Old 02-01-07, 01:09 PM Thread Starter
Senior Shackster
Mike
 
Join Date: Jan 2007
Location: Chattanooga, TN
Posts: 292
Re: Very low budget sub.

I wasn't planning on downfiring them anyway, but thanks for the tip. =)
mgboy is offline  
post #25 of 54 Old 02-01-07, 01:11 PM
Senior Shackster
 
BoomieMCT's Avatar
Boom
 
Join Date: Dec 2006
Location: Fairfax, Va
Posts: 866
Re: Very low budget sub.

Quote:
mgboy wrote: View Post
So If I got two of those, get the enclosure size down to day, 4 c.u. ft, How well should/would it perform do you reckon?
Off the cuff I'd say once tuned it would sound okay. I will plug the numbers into Unibox when I get home to verify. One thing you will want to verify is whether it is best for you to have a $25 active driver with $45 in pasive radiators or just find a $70ish driver you like.

For example, for $86 you can get a Dayton 15" Quatro which would work well with a 300 watt BASH amp and a ported 6 cubic foot enclosure.

Please note that while PR's will allow you to construct a smaller box because you aren't dealing with the volume of the ports, they do not dig any deeper then ported designs. Actually, all things being equal they are usually 1 Hz or so less deep digging.
BoomieMCT is offline  
post #26 of 54 Old 02-01-07, 01:20 PM Thread Starter
Senior Shackster
Mike
 
Join Date: Jan 2007
Location: Chattanooga, TN
Posts: 292
Re: Very low budget sub.

Well I already have the $25 driver, so I guess I'll have to work with what I have. And I always like to try new things and experiment. So, PR's do that job.

18*18*45 box, with the two PR's on the sides of the ED sub.



** Wait, you said 'tune' the PR's? How does that work?
mgboy is offline  
post #27 of 54 Old 02-01-07, 01:24 PM
Senior Shackster
 
BoomieMCT's Avatar
Boom
 
Join Date: Dec 2006
Location: Fairfax, Va
Posts: 866
Re: Very low budget sub.

Quote:
mgboy wrote: View Post
Well I already have the $25 driver, so I guess I'll have to work with what I have. And I always like to try new things and experiment. So, PR's do that job.

18*18*45 box, with the two PR's on the sides of the ED sub.



** Wait, you said 'tune' the PR's? How does that work?
Instead of using a column of air as a "spring", a PR uses a column of air's equivalent mass. Each PR will have a bolt that you can remove and add washers until it is the proper weight. It is actually very easy. For tuning you just install the PR's backwards so you can easily get to the washer bolts. When you get them set right, just flip the PR's around and re-install.

PR's are neat and I'm always tempted to use them. Every time I do I end up doing cost calculations and wussing out and just using a design with a larger port.
BoomieMCT is offline  
post #28 of 54 Old 02-01-07, 01:27 PM Thread Starter
Senior Shackster
Mike
 
Join Date: Jan 2007
Location: Chattanooga, TN
Posts: 292
Re: Very low budget sub.

Ooh. I'd definatey need some help with that. >_> Also, would I have to buy more washers?
mgboy is offline  
post #29 of 54 Old 02-01-07, 01:34 PM
Senior Shackster
 
BoomieMCT's Avatar
Boom
 
Join Date: Dec 2006
Location: Fairfax, Va
Posts: 866
Re: Very low budget sub.

Check out this link - tuning isn't as hard as it sounds. I don't think the PR comes with washers, but the bolt is just an M5 bolt so you should be able to get washers at any hardware store.
BoomieMCT is offline  
post #30 of 54 Old 02-01-07, 01:46 PM Thread Starter
Senior Shackster
Mike
 
Join Date: Jan 2007
Location: Chattanooga, TN
Posts: 292
Re: Very low budget sub.

Thanks, that link helped a lot.

* Hmm, I was doing it wrong, and when I plugged in the right numbers, I get something crazy like 23 lb's on each PR. What am I doing wrong?

Last edited by mgboy; 02-01-07 at 01:59 PM.
mgboy is offline  
Reply

Bookmarks

Tags
budget , low

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