Perhaps a little more info is needed.
This is for my DIY speaker project. I purchased high gloss cabinets that were assembled and sized for a particular woofer, but I have decided to experiment further and change the woofer.
The new woofer specs indicate that it would work better with a smaller sealed cabinet.
So, I would appreciate some creative suggestions to make the internal volume smaller.
ozzy |
|
Wow! Thank you all for some really creative suggestions.
Questions though:
It sounds like the Black Hole 5 would be similar to adding wool, fiberglass, acousta stuff etc. material. These materials are used to absorb and to compensate for a smaller box, not reduce for a larger box. But, I will investigate.
How is the Cascade V applied?
Adding wood bracing inside is the best way to go, but the inside of the cabinet is curved with very little room to use tools inside.
How about PVC pipe sealed at both ends?
Or a cardboard box sealed on the outside of the box with that Black sealant spray that I see on TV?
Can the spray expandable foam be used? Or will that absorb? Perhaps after it is applied I could spray the Black sealant over it? But that would be messy and stinky for a while.
ozzy |
toddverrone,
Will the expandable foam absorb sound like the other products such as wool, fiberglass etc.? If so I think that would be the opposite of reducing the internal box volume. That's why I thought of sealing the exposed area with the Flex Seal spray.
Cutting the pieces of mdf wood and installing them as you suggested might work. I guess I worry that the glued wood may come loose and then rattle or move around.
theaudiotweak,
I will look into the Casacde V sounds interesting.
Geoffkait,
I agree and I was intending on limiting the amount of fill used.
pbnaudio,
Will the Styrofoam blocks absorb? Should I coat them with something?
ozzy
|
So using the Styrofoam...
Please correct me if my math is incorrect or if I am on the wrong track.
First my assumptions.
1 cu foot is equal to 1728 inches.
My present speaker cabinet is 0.75 cu feet or 1296 inches.
The woofers I am getting are said to perform best in a 0.45-0.65 sealed cabinet.
So, if I use 0.45 cu feet as the goal that would equate to about 778 total inches.
I have found available a 8x8x8 styrofoam cube and that would math out to about 512 in total inches.
So, if I subtract the 512 from my present 1296 it would leave the internal volume to be 784 inches or a little more than 0.45 cu feet internally.
Does this sound right???
ozzy |
ivan_nosnibor,
Thank you for that info. I was thinking of just using the flex seal over the Styrofoam IF the Styrofoam alone would act as an absorbent. But it sounds like it does not.
theaudiotweak,
I will order some of the Cascade to be used as a inside lining.
eric_squires,
Wouldn't a mixable 2 part epoxy require putting it into some type of mold? What type of thickness do you suggest?
pbn,
Not sure what type of Styrofoam thickness I should be using. I was thinking 2-4", does that sound about right? I'll try Hobby Lobby first.
ozzy |
geoffkait,
So, what is the negative of having a slightly larger internal volume than optimum size? Lack of bass definition? Low efficiency?
theaudiotweak,
Can you provide a source to obtain the Cascade V? I see something called Cascade listed at Parts Express but it is a spray. Is that it?
BYW, The woofers I have ordered are the ScanSpeak Revelator 18w/8532G-007
ozzy |
asvjerry,
Thank you so much for your information. I am now leaning towards the higher volume 0.65 internals. This means I only need to reduce the inside by 173.
I guess the only issue I have with using 4x4’s is that they would probably need to be just glued at the top inside. And then the cabinet with the 4X4’s glued would be placed on its back to finish the speaker / front baffle install until it can be uprighted again to rest on the stand.
So, I am not sure how well a glued 4x4(s) would stay stationary during that movement. Does liquid nails work that great?
ozzy
|
theaudiotweak,
Thanks. First I’m going to try the Styrofoam. I have a piece that should work out fine cubic inches wise (177.42).
I will be gluing this underneath of the inside top. I just hope it doesn’t come loose or rattle.
Shadorne,
Too much holiday cheer?
ozzy |
toddverrone, cliffkhz, theaudiotweak,
Thank you for the help and the posts.
The woofer I will be using will be located very close to the bottom of the cabinet. Because of this it will be near impossible to place wood at the bottom of the cabinet.
The upper inside top appears to be the best place for any type of cabinet internal volume reduction.
So, at this point, I am first going to try the Styrofoam route. I think I can glue a chunk of it to the inside top. If this rattles or comes loose then the next plan would be to change the front baffle so that the woofer can be raised up and allow the installation of wood or bricks etc. at the bottom.
The front baffle is 1" thick and cutting openings again for the ribbon tweeter and the woofer is not an easy task.
ozzy
|
Well I've changed my mind about the Styrofoam.
It looks like I can install some 2x4's pieces inside. I have some 2x4 material made out of Trex that seems to be quite dense an much heavier than a regular 2x4.
ozzy
|
I just installed the Trex 2x4's.
I installed (2) of them 18" long on each long side placed in the middle of the cabinet.
I figure with that wood my cabinets math out to be .62 cu feet. I already can tell the difference with tighter and deeper bass. The woofers will probably need some time to break in fully, but at this point I am very happy.
I really want to thank you all for the ideas and support.
ozzy |
toddverrone, asvjerry, ptss, theaudiotweak,
The speakers are breaking in quite nicely. I am very pleased with the results.
Thank you for your help.
ozzy |
