REL G1 MkII Subwoofer ReviewPreambleThe first time I heard a REL subwoofer was in July 2013, the sub was next to a pair of Magnepan 3.7 speakers that were driven by a Krell Full Power Balanced 200 (Class A) amp. The subwoofer was the smaller REL Gibraltar G2 and it integrated perfectly with the Maggies, this sub was fast and tight without a hint of overhang all the while going down to 20 Hz, I instantly knew I had to have one.
I had played around with a couple of cheap subs over the years, they all had a slow ponderous sound better suited to movie sound effects. The cheap subs always made stereo music sound worse so except for movie nights they remained turned off.
The retail price for a new REL G2 was $3500. That's a lot of money for a single sub, until you actually hear what a REL Gibraltar sounds like in your system, or better yet, what it doesn't sound like in your system. Once adjusted it is literally impossible to tell if a REL G2 is on. Except now there is space around the instruments, room sounds emerge, midrange and lower treble is clearer, and on the rare occasion there is deep bass the REL clearly lets you know what you have been missing all these years.
The G2 retail price was a lot more than a self-employed woodworker could afford so I started saving and waited... and waited... and waited, never losing sight of my goal. Then, in April 2019 The Music Room had a used G2 for sale and I jumped on it.
The REL G2 transformed my system exactly as I imagined with seamless music from 20 Hz to 40 kHz, not that I can hear that high. I could clearly hear The Cowboy Junkies 'Trinity Sessions' was recorded in a huge church along with the deep boot stomps keeping time on the wood floor. The bass drum on Mickey Hart's 'Planet Drum' rolled around my living room. A lot of artists now put low level beats into tracks, they are like Easter Eggs waiting to be discovered.
The REL G1, G2 and the current No. 31 and No. 32 Reference Series all come with a handheld remote. The remote is calibrated in 1 dB steps which makes adjustments easy, the subs have a digital display so settings are easily adjusted and then returned to the preferred neutral setting. This feature is so important that I will never have a sub without it. Bass on recordings is all over the place, new pop music will blow you out the room while early rock & roll and cool jazz has no bass. When listening to Miles Davis's cool jazz recordings I will raise the sub's crossover and loudness until Al McKibbon's standup bass emerges from the background and he becomes part of the band. Early Rolling Stones albums now can really rock once the deep drum and bass tracks are revealed, all without muddying up the sound. Reset the bass to neutral and Patricia Barber's 'Cafe Blue' puts you in the middle of a small club.
The Gibraltar Subwoofer HistoryThe REL G1 and G2 with their distinctive teardrop shapes were first announced at the 2009 CEDIA Expo, the G1 was first demoed at the Feb. 28, 2010 Sound and Vision: The Bristol Show. The G2 arrived later that year. The two subs had a long life with the G2 being discontinued about the time I bought mine in 2019. The G1 was upgraded to the MkII in 2017 and then silently disappeared from the REL website in August 2022 when the new No. 31 and No. 32 Reference subs were announced, which are bigger, better, badder and more expensive than the G1 MkII.
Home TheaterMy stereo and home theater has always been integrated since the early days of the Hi-Fi VCR and matrix audio. Both setups have slowly improved with the home theater evolving to a 7.1.4 Dolby Atmos setup in the last few years. I now have big theater sound and the 10" REL G2, as excellent it is with music, wasn't quite up to the task with the latest blockbuster movie sound tracks (damn you Christopher Nolan). Movie sound has dynamically improved and it was time for the sub to improve along with it.
The REL G1 MkIIThe G1 MkII is a beast at 22.5" wide, 26.8" deep and 18.2" high and weighing in at 108 lbs. The sub has a single 12" long throw (2" forward and back) carbon fiber cone in a curved sealed box powered by a 600 watt ultra high-current class A/B amp. The manual says:
REL's use massive power supplies that can require 3-4 days to fully charge. During this time, your G1 Mk II sub will begin to play louder. This is normal. It may require the user to lower the volume slightly during this period.At $5500, the REL G1 MkII has always been above what I felt comfortable paying. The new REL No. 31 with the 12" driver is $7000, that's into forgetaboutit territory. What's a guy to do? The answer is the same as before, wait.
I was poking around the internet recently when I noticed that
Upscale Audio has open box REL G1 MkII subs on sale for $4395. Not cheap but since they are discontinued... this is probably the last time to get a new G1 MkII with full factory warranty and free shipping. So throwing all caution to the wind, I bought one. (Still available when I posted)
SOLD OUT https://upscaleaudio.com/products/rel-g1-mk-ii-reference-subwoofer-piano-black SOLD OUTYup, that did it. Solid, loud, tight, earth shaking 15 Hz bass. Take
that Mr. Nolan!
Comparing the G2 and G1 MkII

For home theater, the G1 MkII wins hands down. The sub has the same clarity as the G2 but moves a lot more air effortlessly, it's the combination of a larger A/B amp and a 12" driver with a longer 2" stroke. For music it's a bit of a toss up. The G1 MkII is still breaking in but I feel the G2 is a tad quicker. The G2 has to work a little harder to move the same amount of air, it sounds a little punchier, the effect is addicting. The G1 MkII is more natural with lows effortlessly spreading throughout the room with definitely more space around the performers on naturally recorded music, -6 dB at 15 Hz will do that.
The big REL subs are sub-bass subs and designed to be used with full range speakers using the high-level speaker terminals. My Salk HT2-TL speakers go down to 34 Hz, the REL sub crossover is set to 34 Hz, there is no bass hump using either the Stereophile Test CD with a Radio Shack meter or the Spectroid phone app, I got lucky with my room dimensions. The smaller REL subs can be crossed over higher but don't go as low.
The Salk HT2-TL speakers are similar to studio monitors and are less forgiving by nature, never harsh but very revealing of bright sounding anything, from electronics to recordings. Reviews of the G1 MkII mention how midrange and lower treble sound clearer, it's true but I have no idea how this phenomenon works. This effect also mellows out the HT2-TL, like changing out JJ tubes for Mullard, not a huge change but very nice just the same.
The original G1s are always for sale, usually for around $2250. I passed on those, they are getting old and the MkII is an all new design from the driver to the amp to the analog filters and crossover that fixed the long term reliability and other flaws of the original.
Over The Top BassI still have the REL G2 in the house, a couple friends would like to borrow it. Eventually I will sell it because I don't have room, my house is only 750 sq ft. REL always recommends using two subs. I then had an epiphany: "Hey, I got two subs, what the hell am I waiting for?"
Music is interesting but the 2nd sub location is not ideal. Maybe I can hear an even larger recorded space but the added bass is a little too much of a good thing. But for movies, OMG!

I have this test album: Blade Runner 2049, Denis Villeneuve's masterpiece with music by Hans Zimmer. Sound demos usually include explosions, submarine depth charges, Godzilla stomping and roaring but nothing has sustained 15 Hz - 30 Hz bass that goes on for 15 seconds or more like this soundtrack album has. Track 1 - '2049' and track 3 - 'Flight to LAPD' will tax any home theater. Playing both tracks at theater levels scares me, I eventually have to turn it down. Everything in the house vibrates including my body. Eyeballs are filled with fluid, when that fluid starts vibrating and my vision starts getting blurry it's time to turn down the volume, yet another successful experiment. Don't try this at home kids.

ConclusionCompared to the other subwoofers I have heard, the RELs are still the best. The guys in our audio club have terrific sounding systems with dual Rythmiks, dual open baffles, a REL S/510, and a variety of smaller subs. Those subs fill in the bottom octave but none do what a G1 MkII or G2 does. The open baffle subs can create a huge sense of space like the RELs but work best with open baffle speakers and you need a huge room to make it all work. Rythmik subs are excellent for the price but I have never heard them punch hard, their bass seems softer. Smaller subs are just that, smaller.
I like this hobby because there is so much variety, each audio system is like a gourmet meal for the ears. Get out and listen to as many audio systems as possible, each will be different with a unique flavor combination. And when I hear something I like, I start thinking about how it can be added to my system to make my music listening experience even more exciting.
Wayne
More Info and ReviewsREL G1 MkII retired web page
https://rel.net/uk/shop/uncategorized/g1-mark-ii/REL chief designer John Hunter describes the REL G1 MkII
https://www.youtube.com/watch?v=Ct8iT_NkEhMUpscale Audio's Kevin Deal and John Hunter discuss the REL G1 MkII
https://www.youtube.com/watch?v=pSHkpy2280QPositive Feedback Gibraltar G2 Subwoofer Review
https://www.positive-feedback.com/Issue76/rel_gibraltar.htmTONEAudio Gibraltar G2 Review
https://www.tonepublications.com/review/rel-gibraltar-g-2-sub-bass-system/The original G2 driver has a design flaw, the woven wire leads from the terminals to the voice coil are glued to the spider. Over time the leads close to the voice coil get wire fatigue because of the 1-3/4" maximum cone travel and break, this is a catastrophic failure and cannot be repaired. REL sells a G2 MkII 10" driver that fixes the flaw and are electrically and mechanically identical to the original so it is a drop-in replacement. The MkII driver costs $800 each so I would not pay over $1100 for a used G2. A G2 with the MkII driver will easily surpass any $2000 sub available today. I don't know if the original G1 sub 12" driver has the same design flaw.