JL Audio 10W3V3-4 Mod on a Sunfire Truesubwoofer MKII

[OldiesButGoodies]

It works as advertised by Rev in his post here:  http://vintagehifipgh.com/forum/index.php?topic=2010.msg19049#msg19049.  The JL Audio driver looks puny and weighs half as much as the hivi,  but it sounds better,  much better integration with the mains.  I think it basically has atad faster response and is tighter - just my theory.  The JL Audio logo does not align perfectly vertically, but who cares,  it sounds great. 

I am wondering about coupling the sub with the floor.  I have spikes on it right now to keep it steady on the floor.  Would it do better floating on the carpet?  (I know,  you are going to say "try it both ways...") - I am seeking a scientific theory to back up the approach.  To, anchoring the sub to the floor forces the cone to move the air instead of moving the sub.  Some websites promote the opposite,  citing the horros of coupling the speaker to the floor.  Who is right?



Untitled by JSifontes, on Flickr


Untitled by JSifontes, on Flickr


Untitled by JSifontes, on Flickr

I took the radiator out so I could wire the super short leads to the JL woof after mounting it:


Untitled by JSifontes, on Flickr

The hivi looks 2x as impressive - cast basket - gynormous magnet.  But that is all skin-deep,  the JL is faster.


Untitled by JSifontes, on Flickr

Chassis ready:


Untitled by JSifontes, on Flickr


Mounted:


Untitled by JSifontes, on Flickr

Hooked up:


Untitled by JSifontes, on Flickr

Ready to test:


Untitled by JSifontes, on Flickr

[TNRabbit]

Less movement = better accuracy.

[OldiesButGoodies]

Rabbit - the other theory is that the spikes couple the speaker to the floor and the floor then vibrates sympathetically with it and runs the sound,  sort of like a poorly braced speaker enclosure.  That makes some sense, specially on a wood floor (would not make sense if the floor is concrete). So that has me wondering.  I have seen it described as the floor coupling problem. 

[EndersShadow]

They also do make decoupling devices.  Such as the Auralex Gramma pad.  I have one with my Polk PSW125 and IMHO it made the bass sound tighter.

I use mine on Carpet too boot and then dont have any spikes on my sub.

[Reverend]

With the new driver, you will see less movement of the cabinet.  Both Tom and I are seeing this firsthand.  The cabinet still shakes but because the new driver disperses energy better, we didn't see it walk at all.  Of course I'm assuming the shop is carpet over concrete which is what I have in my basement as well.  What also works well is that perforated rubber drawer liner.  You can pick this stuff up at the dollar store.  I'd give that a shot.  It's slightly tacky and provides some insulation.

[Kingman]

What also works well is that perforated rubber drawer liner.  You can pick this stuff up at the dollar store.  I'd give that a shot.  It's slightly tacky and provides some insulation.

...Great idea! never thought of that. Got some in the garage...will try it out. 

[OldiesButGoodies]

Will try the liner idea and remove the spikes - I know my wife uses it in the kitchen so there has to some leftover somewhere,  or a shelf will go without for a while so I can experiment. Good idea. 

Rev - what are you going to do with the old hivi driver?  Mine is not signed by Bob,  so I see an epay posting in future.  I can hardly see a scenario where I would put it back in the Sunfire (other than perhaps to sell it). 

OBG

[Reverend]

Rev - what are you going to do with the old hivi driver?  Mine is not signed by Bob,  so I see an epay posting in future.  I can hardly see a scenario where I would put it back in the Sunfire (other than perhaps to sell it). 

OBG

Already sold it.   

[TNRabbit]

The Sunfire subs are better if you keep the crossover below 50 hz.

Also, if you use spikes AND a HEAVY weight on top it will give you a more accurate bass.  One of the issues with the small enclosure is that they will "walk" around & that is just not good for accurate bass reproduction.

You guys should check out an EPIK sub.  Excellent quality, U.S. made, & their prices are among the best I've seen for a world-class sub.  They aren't JL Audio good, but they also cost about 1/10th as much~

[Reverend]

The Sunfire subs are better if you keep the crossover below 50 hz.

Also, if you use spikes AND a HEAVY weight on top it will give you a more accurate bass.  One of the issues with the small enclosure is that they will "walk" around & that is just not good for accurate bass reproduction.

Spikes and weights are no longer needed.  As I mentioned previously, the driver movement of the JL makes the cabinet much more stable and the accuracy is increased 10x.  The crossover can also be run much higher to take advantage of the higher range that the JL driver has.  All previous issues with the sub can be thrown out with this mod. 

[camaross1475]

Wonder if the sub would get tighter if the radiant sub was removed and replaced with a block off plate? MDF? Steel?