A few more sub woofer questions..

SS4927

Member
2013-12-08 3:15 pm
How would these fair in 1.00 cubic feet closed box with EQ?

Or two per 1.00 cubic feet single chamber CB, also with EQ.

Another plan had me making two 1.00 cubic foot baltic birch sealed boxes, Im half way there having completed one. Then got to thinking what If I had some better suited sub drivers, and since Ive already invested half of the time. That plus I can get a good price on three of these SB acoustics if don't hesitate. The chap said he wants a prompt answer as he will or will not bother advertising them basing it around my decision https://www.madisoundspeakerstore.c...cl45-8-8-polypropylene-cone-sub-woofer-8-ohm/

The example the page notes is roughly half the size of mine which begs these questions. Although that may or may not be an optimum volume what could I expect with double the volume, more extension with less EQ? Or results that leave a lot to be desired.

As I was also suggesting I could deviate from original plans and house two of them in a single 1.00 cube foot sealed cabinet with the appropriate baffle alteration and a little shifting of the internal brace placement.

Ideally I would like if the 1.00 cubic foot previous planned closed boxes could work well while cancelling out more work, for me the diy'er.

Or ultimately I could always start over.
 
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So...

Bigger sealed cabinets are more efficient at LF than smaller sealed cabinets. Those drivers will produce an acceptable Qtc in ~0.5cu.ft, as recommended by the manufacturer. A bigger sealed box would give less output around 60Hz, and more at the bottom end. Since its a sealed box, you'll probably have EQ available. In which case, the difference will be lower power requirements at the bottom end, resulting in a (probably slightly) cleaner sound compared to a smaller box.

If you wanted, you could put a pair of those drivers in a cabinet. You'd need some power, but there'd be plenty of output. By putting them on opposite sides of the cabinet, you'd cancel out most of the forces acting on the cabinet, helping to prevent structure-borne vibrations (through the floor etc) and stopping the cabinets walking around at high volumes.

They're nice drivers - I'd snap them up if you've got a good deal.

Chris
 

djk

R.I.P
2001-02-04 4:23 am
USA
A 2 cu ft 2nd order sealed box with an F3 of 30hz can only be 0.18% efficient (84.55dB).
A 2 cu ft 4th order vented box with an F3 of 30hz can only be 0.36% efficient (87.56dB).
A 2 cu ft 6th order vented box with an F3 of 30hz can only be 0.90% efficient (91.54dB).
 

SS4927

Member
2013-12-08 3:15 pm
Thanks very much, I dont think I could ask for more helpful string of answers for my sting of questions.

I do have an EQ for them yes. I also like that they are 8 ohms and the thought of running them tandem parallel on a class D in either box vol. venture. Im leaning a bit more towards the 2 x 1.00 cf. with EQ as it sounds like it may better suit my listening styles and tastes. Not to say things will be too quiet for me when I want to shake things a bit. The amp I have is bridgeable to achieve 400w x 1 channel @4.

With all that being said I will probably be willing to build a smaller box to house the two drivers in later though in some time to see how everything sounds the other way.
 

SS4927

Member
2013-12-08 3:15 pm
I decided to take all three on he will knock a little more off what I thought was a pretty good price already, so $240 total.

I would like to box all three but I don't know if my amplifier is up to it. It will go 200x2 or [email protected] ohms respectively. I would like to keep impedance at 4ohm or close, aside from swings not much lower.

Being that the subs are 8 ohms each and that there are 3 of them, what would be a best way to go about wiring them?