These are a clever way to convert my acoustic kit into a practice kit. A little pricey, and I was a little apprehensive at first, but the attenuation and feel is great. I didn't see a whole lot of info explaining this product so I'll try and fill in what I feel are a few gaps.
The heads themselves are like a Remo Silent Stroke or similar mesh head that you'd see on e-drums and the like and there's a soft black dot in the center. The mesh head fits into an interior channel in a heavy rubber ring. The ring is about 1 1/2" tall and about 1/2" is exposed above the head and about 1" below. That 1" side stretches over your snare and tom hoops. RTOM says that for die cast hoops you may need straps (sold separately) to hold it on, but these fit snug on both my stamped flanged hoops as well as die cast. For kick, the Black Holes fit INSIDE the hoop and you stick on some foam to the exterior of the rubber ring to hold it in. This also fit securely and I also didn't need the supplied extension bracket for the pedal in order to play comfortably.
Another important thing: because these heads aren't stretched tight over a hoop, they need to be pre-tensioned so they're not flabby and floppy. RTOM does this with a steel rod, a few mm thick that's formed into a circle and mounted inside the head. A turnbuckle lets you exert more or less pressure to stretch or compress the ring and the head is tensioned without being stretched over a rim. Pretty clever and I've been happy with how it feels.
Because these are mesh heads, your kit will feel like a nice electronic kit and not real acoustic drums. I can live with this, but yes, it does feel spongier than a regular mylar head. I'd say the attenuation is good, probably 25% of what my acoustic kit is normally. I'm using Zildjian L80 cymbals and the balance is in the ballpark.
You should know if you're getting into these and low volume cymbals that your kit is going to sound pretty lame. These Black Holes are replacing Evans neoprene SoundOff pads for me and are actually a big step up, as now I can actually hear some acoustic drum resonance happening. Real drums sound awesome. These Black Holes do not sound awesome, but my drums sound acceptable for practice and I'm not annoying neighbors and harming my hearing. My kit sounds pretty balanced with these, but maybe the kick is a little louder than toms and snare.
Please note that a 75% reduction in sound for me means now my next door neighbors can't hear me playing, but other people in the house still can. This may not be acceptable for some folks, so be aware. I bet if folks need, more padding could be added under the Black Holes to quiet them down even more, but 75% is good for what I need.
What remains to be seen is durability. I've had these for a week and played rock and punk on them and there are no dents or noticeable stretching. These mutes are 3 times the price of a regular head so I hope they have a long life. Because the Black Holes are essentially a regular edrum mesh head with a rubber ring and steel stretcher. It seems like you might be able to just swap the mesh head part out, which could be a huge cost savings. RTOM literature didn't make that clear.
Overall I'm super impressed with these but hope they hold up.
Note that I purchased the 12", 14", 14" and 20" heads separately but I feel like this review would best apply to the complete set. I wish they had a few other combos available but this configuration didn't work for me.
RTOM
