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acoustical stuffing / sound dampening subwoofer cabinet REL BRITANNIA B1 subwoofer

Hello,

 

Quick question on acoustical stuffing / sound dampening in a subwoofer cabinet.

I am the 2nd owner of a REL Brittania B1 subwoofer.

Opened it up, and NO stuffing. A bit surprising. My guess is the original who was a dumb &*(&#$   removed it.

I am guessing there should be some stuffing in the cabinet.

 

IF SO, I am looking for recommendations as to how much to put in the cabinet and where.

THANKS for the help!

Please see pictures for view of interior of cabinet. Bottom-Middle- Top pictures

 

FYI--- Interior of cabinet is approximately 13” x 15” x 19”

 

 https://drive.google.com/open?id=0B01U3HhYR3nZZUJ6U0lzZVNMYkE

https://drive.google.com/open?id=0B01U3HhYR3nZbGZNR1ktRHBOMmM

https://drive.google.com/open?id=0B01U3HhYR3nZS3kzSWpOaF9ySmM

REL BRITANNIA B1


stevethe4th
auxinput
2,920 posts
 

Depending on cabinet volume and tuning frequency, some drivers may want a port that is 25-35" long (based on 4-3/4 diameter).  That's what I really mean.  A shorter port means the tuning will be at a higher frequency, which could mean a bump/increase at something like 35hz where the port and the driver are working together.  This may not be really bad at all.  It's up to you, but the goal would normally be to engineer a flat response with a controlled roll-of.

Do you have a copy of Bass Box Pro?

https://www.parts-express.com/bassbox-6-pro-software-cd-rom--500-923

It might be good just to buy at $129.  Then try to measure/calculate the actual interior volume of your cabinet.  Then select a driver at random (say ScanSpeak 30W/4558T) and then play with the Fb port tuning frequency until you get a 4.75" port close to the 17-18" length.  Then do a frequency response graph to see how it looks.  I did a few, and some may have a very slight bump at about 40hz.

stevethe4th OP
37 posts
 
Great advice, that was actually going to be my next step down the rabbit hole!! LOL

I that worth $129 versus some of the free software out there?
timlub
2,039 posts
 
My experience with any type of stuffing on a ported or vented box is closer to Dukes.  It isn't always about the slight changes in effective cabinet volume as much as it is the dampening effect and the amount of output or cancellation because of wave front cancellation inside the box. On a ported box,  I personally like 1.5 to 2 inches of unfaced fiberglass glued to the paralleled walls.  It does a great job.  Some of the foam type products mentioned do a very good job for dampening also, but be aware the more dense or hard the surface is, things start to change from effectively enlarging the box to effectively making the volume less.  
Good luck with all of this. 
Tim
auxinput
2,920 posts
 

I haven't used other software, but if you are serious about building your own subwoofers, Bass Box Pro is really the best.  You don't have to buy anything.  It's up to you if you are really picky about how a sub performs.

You could just buy a SanSpeak or Morel subwoofer.  Then do dynamat damping on the interior walls, and then spray-glue some Acousta-Stuf Polyfill on the inside walls.  Like timlub said, the stuffing will damping some of the peak that happens right before frequency roll-off.  This might help work with some of these other subwoofer drivers.

auxinput
2,920 posts
 

If you're still looking for possible drivers, the Rythmik Audio appears to be very nice:

http://www.rythmikaudio.com/DS1200driver.html

The specs say the DS1200 works fine in a 3-4 square foot vented cabinet.  I don't know the pricing, but you can contact them.  They are in Texas.

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