EARTHQUAKE Sound SLAPS-M12v2 12-Inch Mass Tuned Passive Bass Radiator for Home and Mobile Audio Subwoofer Enclosures

I was given am old 12" MK powered sub, with a dead amp. After using it for a while , I really did not like the sound, is was not low enough. So I decide to retrofit the unit by removing the amp, closing the gap and slapping a 12" slap in its place. The result has been tremendous and strong clear bass, it has taken the sub to new levels. You can add weight to tune it to your liking by using washers and nuts. It has a very robust and strong thick rubber surround with a very respectable XMax. The unit is very nicely built, very robust and ready for low bass "abuse".

This was my first time adding a passive radiator to a sealed speaker. It's amazing how much additional volume this adds to such a small box. The sub digs deeper without unloading like it would with a port. It sure does shake the box around when it hits the resonance with that weight... the radiator is much heavier than the woofer coil. It's a good idea to install two radiators on opposite sides of a box, i might try that next. I would buy this again. I added 1 to a single Skar VXF 12 in 15 cubic inches.

Got 8inch to replace broken Bass Radiator. I had to spend over 1hr to do modifications.1. 8 inch port did not fit, I had to re-sand opening.2. Mount holes did not fit, I had to re-drill everything.After it was complete, it sounded great but again, a lot of work required.

I absolutely love the performance of this passive radiator. This is very likely the highest performance passive radiator on the market today.1. Tuning it though is made unnecessarily difficult though. The screw & nuts holding the tuning weights have some sort of thread lock glue on them that is quite permanent & very difficult for someone like me who is disabled & don't have a lot of power tools in order to get it off. It took me a couple hours of trying different ways to remove it without damaging the radiator.2. They don't provide any extra tuning weights. I had to go to the hardware store a couple of times in order to get weights. The first weights I bought were totally inadequate, but did use one as a large washer to help hold in the tuning weights that I eventually bought. This was necessary due to the large size of the hole in the weights that did work. Otherwise the bolt could have pulled through damaging the radiator. It would have been very nice if they had actually provided a set of tuning weighs for various tunings in the box.3rd, they need to provide a longer bolt.About the performance. You can gain a lot of performance & headroom using this passive radiator. I gained almost 10db at my tuning frequency of 16Hz & 5db at 25Hz. This represents a minimum of having at least 3 times more power without having to actually have a bigger amp. At 16hz that is almost equivolent to having an amp 10 times more powerful.Other than the issues listed above this appears to be a very well made passive radiator.People say it is cheaper to build a ported speaker. True, however if you make a mistake in your cabinet when utilizing the cabinet walls as part of your port it just became more expensive than a good passive radiator if you make a mistake in tuning as you will have to start from scratch again. With a passive radiator you can just add or remove weights to correct your tuning.A passive radiator won't be as loud as a port in a properly tune system but this one will get you close. It is truly super high performance. You also won't have unplanned resonances as you would with a port.Like the sound of your sealed system but need more output without a bigger amp or losing that nice tight sealed system bass. Look no further than this passive radiator. Make sure you get some DSP unit though so as to help balance the system. My sub amp has built in DSP but fortunately I didn't have to make any adjustments other than turning off my 5.5db bass boost @16Hz & adjusting the overall subwoofer volume down 5db.

I own four of these now. Even talked a few friends into purchasing them as well. Good quality product. Still confused on the version. 12 V3 or the added V3 on the end. I must be blind. I didn't see any difference between the point or version 2 versus version 3. Maybe it's marketing? Maybe it's the manufacturing material but they are quality but I don't agree with the price of them at this time. But the price of everything else has gone up too. But back to the review. These don't appear to make any type of flapping noise they handle. All of the pork pressure frequencies a port would use, but instead they stroke their suspension in and out to create the base wave from that port instead. Thus, they're silent. If you're looking to do a sealed enclosure and it's too small, you might put one of these in there. I've done experiments from using the old Sunfire subwoofer with these to a good high quality car audio f or home audio subwoofer with these as well. Don't think you'll go wrong. Give him a try. They are much better than using ports.

The media could not be loaded. I assembled a home subwoofer with these passive radiators. The frequency range turned out to be 24-120 hertz. As a home sub on 5.1 acoustics, Dolby Atmos was almost perfect. At low frequencies the whole house shakes. There is no bass reflex noise, the entire range plays perfectly. Box 0.7 ft.

I have 2 12in slaps paired with 1 12in sub running around 1200-1500 watts in a properly designed enclosure for this setup. My initial impressions, I was amazed to achieve the output and sound quality I was able to achieve with these. Fast forward only two weeks and I start hearing what sounds like a loud interior panel rattling. After further inspection, I noticed one of the slaps has a crack on the front side, Starting right below where the weight is mounted internally. So I exchanged it through amazon return thinking i received a bad unit. Not even a week later another crack in roughly the same area. CONCLUSION: these do allow for big deep bass from a smaller sized enclosure but will only last if you’re using them on a low power system, maybe 1000watts max if you use two passives per driver, maybe 500 max if you use 1 passive per driver.