Possible to re-cabinet an existing sub?

The situation - see pic - is I need a widescreen monitor stand. The Velodyne 12" sub is, er, temporarily serving the purpose for a bass extension test. Thinking something along the lines of second pic, albeit taller. FWIW - I also have a Dayton 12" front firing ported sub I could re-purpose.

Would it be possible to build a shorter, wider cabinet for the Velodyne components combining the function of subwoofer and monitor stand? One would think cubic volume is volume for the same driver / port dimensions... I have 13" depth on the tile slab - a little overhang in OK.

Let's say it works out that I have ample opportunity for increased cabinet volume. Could I then make it a sealed design? How much (1.X) volume increase to keep, roughly, the same performance between a sealed and ported enclosure?

Finally, if I wanted to turn it into a downward firing sub, with airflow exiting on 3 sides, does this then require a complete rethink of how the existing amplifier EQ is done? I seem to vaguely recall "bandpass" along with downward firing driver yields flat room response.

Thanks for any help with / commentary on this idea. (99% of the time, the sub is absolutely loafing, so I'm not real worried about rattling the monitor to death)
 

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Last edited:

conanski

Member
2013-03-31 3:53 am
Cabinet shape doesn't really matter as long as the ports don't get obstructed and the internal volume remains the same. A sealed box for the same driver would be smaller but even if you made it much bigger it won't match the ported box in lowend output, some EQ will be needed for that.
A bandpass box can produce more output than sealed or vented over a narrow range but it is very driver specific and it's not likely a driver designed to be in a reflex would work very good, and this design has a lot of group delay making them sound slow
 
Finally, if I wanted to turn it into a downward firing sub, with airflow exiting on 3 sides, does this then require a complete rethink of how the existing amplifier EQ is done? I seem to vaguely recall "bandpass" along with downward firing driver yields flat room response.

Could, just depends on how much floor loading you use. Note the driver must be suitable for downfiring: Resources - Woofer Mount Up Down

GM
 
A bandpass box can produce more output than sealed or vented over a narrow range but it is very driver specific and it's not likely a driver designed to be in a reflex would work very good, and this design has a lot of group delay making them sound slow

True, a max flat BP alignment will be tuned higher, so need to start with a lower Fs for a given tuning.

It can, but properly designed/tweaked they can sound as 'tight'/'fast' as a compression bass horn. I mean how many BP6 THs have been reviewed as 'slow' once TD, EQ'd? ;)

IIRC, Dr. Geddes did a 'killer' performing BP4 with several different length pipe vents to smooth out its response for a manufacturer some years ago and in recent years even higher order BPs have been developed for prosound that's gaining in favor with DIYers, so let's not dismiss them just because so many bad ones have been/still are being built.

GM