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Is There A Replacement Passive Radiator for a 12" Sunfire True Subwoofer Signature??

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And the answer is 'Yes' and Vicious-Poodle has created THE SUNFIRE TRUE SUBWOOFER SIGNATURE 12 EARTHQUAKE SOUND HYBRID MONSTER!!!! MWAHAHAHAHAHAHAH (Lightning crackel and thunder crash!)

So, about two weeks ago, I purchased on EBay, a used Sunfire 12 inch Signature with a bad amp plate for under $400 in piano black. I always wanted one and that price was a steal. When it arrived, I swapped in the plate from my 10 inch Sunfire Mk II. I was horrified to hear a terrible Death Rattle in the passive radiator. All my research showed no one sells a replacement and the odds of finding used body parts for the 12 incher are slim. I took out the PR and tried rubberized epoxy where the rubber meets the wood disk, glued around the center weight, tried everything, and still the Death Rattle. What to do. And I don't take no for an answer.

While watching TV I had an epiphany: The Earthquake Sound Supernova 12 looks and works a lot like this Sunfire. Maybe that passive radiator can be bought and fit in? A search on Ebay showed that there is indeed an Earthquake Sound 12 inch passive radiator for sale. The one closest in size is the SLAPS M-12. Looking at the specs, the cut out needs to be about 1/8th inch larger. The SLAPS technology is better tech than the original passive radiator. There is no spider, glued on disk, heavy center weight that can rattle and cause issues. And it's very affordable! (The original seller on Ebay paid for it! How nice is that?)

With a huge wood file in hand (see photo), I enlarged the opening enough for it to fit in snugly. Took about an hour w/ interruptions. The bolt pattern is identical to the original so no new drilling of holes is needed. All the hexagonal bolts were replaced and tightened (one bolt was stripped so I used a larger screw and nut in its place.) Everything was nice and tight so it was time to give it a try.

I was beyond amazed! I did a frequency response sweep and there was huge output you feel at 20 HZ diminishing to an unbelievable 14 HZ. The SLAP-12 has like 3 or 4 inches of excursion. Where the Jurrasic World trailer would crash my Sunfire 10's, this monster had no issues. The bass was awesome. It could even do that 16HZ organ piece (Symphony No. 3 (Saint-Saëns).

Since this is a better passive radiator than the original, I ordered a SLAPS M-10 for my MK II Sunfire. I think that might even fit in with less filing. I will let you know how that works and if it improves the performance. (Right now these 20+ year old subwoofers seem to easily get over-driven on new material. My theory is it's the passive radiator.)

So, everyone, there is a replacement passive radiator for your Sunfire Signature 12. I will let you know in another week, if the same can be done for the 10 inch model.

Best wishes and stay safe!




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I'm sad that no one really seems to care on this forum about such a great discovery! However, as promised, even though I am probably talking to myself, the EARTHQUAKE SOUND SLAPS-M10 passive radiator, is a perfect bolt in, no modifications needed, replacement fit for the 10 inch Bob Carver Sunfire True Subwoofer. It was a simple unbolt removal and bolt back install. A custom, perfect fit. The change and increase in bass was DRAMATIC! I couldn't believe the difference.

I strongly suggest, even if your passive radiator (right side of the amp plate) 
is not broken, replace it with this model and you'll be thanking me!




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1 hour ago, Vicious-Poodle said:

I'm sad that no one really seems to care on this forum about such a great discovery!

Not that no one cares. I found the post quite interesting and wonderd whether the whole Earthquake Sound Supernova is good. 

Don't know how many "classic New England speaker" fans have Sunfires so that probably accounts for the apparent indifference but it's always cool to know a member found an innovative solution to an apparently insurmountable problem.


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14 hours ago, JKent said:

Thanks, Kent!   I appreciate the comment.  I would think Sunfire are now considered classic.  I would love to hear the 15" Supernova Model.   That has to put out insane bass.  It's very expensive, however!  Also surprised how affordble the Passive Radiators were on Amazon!   Stay Well!


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