128h woofer box size help

[tyler]

H i this is my first post so be gentle.
I have a pair of 128h woofers laying around and I would like to make some subwoofer boxes for my main speakers to sit on top of.Here are A couple questions.


1. what is the best for this woofer ported or sealed?

2.Anyone tried them in a ported box if so how did they turn out?

3.if ported what amount of cubic feet used and length of pot and diameter?

4.are there any posts onthis website using the 128h drivers..


thanks Tyler Allred

[duaneage]

H i this is my first post so be gentle.
I have a pair of 128h woofers laying around and I would like to make some subwoofer boxes for my main speakers to sit on top of.Here are A couple questions.


1. what is the best for this woofer ported or sealed?

2.Anyone tried them in a ported box if so how did they turn out?

3.if ported what amount of cubic feet used and length of pot and diameter?

4.are there any posts onthis website using the 128h drivers..


thanks Tyler Allred

1. Definately ported, sealed box does not yeild much bass.

2. I just finished a pair yesterday. 1.63 cu ft tuned to 32 hz. Bass is tight and clean. 4411 used same woofer with 5 mh choke in series. Also used in L-150 and 4312 series.

3. Will also work in 2.5 cu ft with deeper bass and 28 hz tuning but the cabs might be a bit big.

4. Use the search feature for 4411 and other models that use the woofer

[duaneage]

Arguably the best bet for a 128H based sub is the L150/L150A sized enclosure.

http://audioheritage.org/vbulletin/showthread.php?t=3194

Brace your boxes better than the L150/L150A. Go with something like a 1.25 : 1.0 : 0.8 ratio.

I believe the L-150 used a passive radiator design, might be a bit tricky for home construction without the right passive radiator and the proper xover network. If your looking for Sub duty a powered amplifier driving two 128H in a 3 .5 cu ft enclosure that is well braced and tuned to 32 hz may be the ticket.

You can use shareware box software like BOXPLOT (google boxplot to find it) and run some curves.

VAS 9.8 cuft
FS 23
QTS .24

Submit that there are two drivers in one box if designing that way.

[DavidF]

Will this truly be a sub woofer? Used for 100hz and below? Then a box loading ala the L150 will provide extended low end- 4 cu. ft., 4/6 inch port or 3/3 port.

Optimum loading is in the 1.7 to 2.5 range. A 1.8 box with a 3/8.75 vent; 2.5 box with a 4/8.5 port or 3/4.25 port.

Jbl recommended 2.5 used a low woofer. Monitor and bookshelf models take this down to around 1.7. This adds punch/thickness in the bass but limits extension.

DavidF

http://www.jblpro.com/pub/manuals/enclgde.pdf

[Zilch]

Build Citation 5.4 or this GordonW bandpass design with one 4" port 7.25" long:

[Zilch]

Heh.

We all oughta build our designs and send 'em to tyler to test. :p

[duaneage]

My 4411s used 128H in 1.6cu ft 3inch port 6 inches long. Had 5 mh inductor on the crossover adding .5 ohms series resistance.

Bass is real tight and defined though not very deep. I like em' anyway.