GR Bass AT-112H – Structural Reliability Issue

[gil_mor]

Hi Folks,
Sad story about my beloved GR Bass AT-112H.
About 3 years ago, I bought it from a fellow TBer and it’s been awesome.
I'm an older "responsible adult" kind of bass player. I'm very careful with it, always put it in the backseat of my car, don't slam it against things, etc. I use it about 5 times a month.
Recently, I noticed the bottom front edge has separated and twisted, and the metal siding on the bottom is getting unglued.When I took out the cover, the wooden piece that is Velcroed to the cab also got unglued.
See below.

I reached out to GR and after a little back and forth, they are saying that some of the damage can’t be fixed and offered me a nice deal on a new cab (minus the 12” driver).

While I appreciate the product support and offer, a cab should last more than 5-6 years. It sucks, but I have to change my recommendation to “Don’t Buy” these cabs.
I love everything about it other than the structural reliability.
YMMV, but i'm going back to wood.

 

[Jim C]

FWIW GR also makes a wood cabinet AT 112-H that is standard construction but still really light.
I have one.

 

[gil_mor]

FWIW GR also makes a wood cabinet AT 112-H that is standard construction but still really light.
I have one.

True, but I was really excited about using the lightest 1x12 cab possible.

 

[gtirard]

Hi Folks,
Sad story about my beloved GR Bass AT-112H.
About 3 years ago, I bought it from a fellow TBer and it’s been awesome.
I'm an older "responsible adult" kind of bass player. I'm very careful with it, always put it in the backseat of my car, don't slam it against things, etc. I use it about 5 times a month.
Recently, I noticed the bottom front edge has separated and twisted, and the metal siding on the bottom is getting unglued.When I took out the cover, the wooden piece that is Velcroed to the cab also got unglued.
See below.

I reached out to GR and after a little back and forth, they are saying that some of the damage can’t be fixed and offered me a nice deal on a new cab (minus the 12” driver).

While I appreciate the product support and offer, a cab should last more than 5-6 years. It sucks, but I have to change my recommendation to “Don’t Buy” these cabs.
I love everything about it other than the structural reliability.
YMMV, but i'm going back to wood.View attachment 7365829View attachment 7365830View attachment 7365831View attachment 7365833

It's a bummer but I'm not surprised.
I've had a GR Natural Fiber cab. At the time I was also looking for the lightest possible cab.
The first cab I've received had a vibration problem. The GR Bass support was super efficient, they repaired it quickly. But it left me with a lack of confidence.
It's no longer my ultimate goal, now I think a cab should simply be "light enough".
If I had to buy a GR Bass again it would be a wood cab, because they are light enough, in the same weight category as Barefaced or Markbass.

 

[xiaoma]

Thanks for the update. I respect a company innovating to make our life easier (and keep our backs healthy) but it seems they need to figure out how to do it without them breaking down after only a couple of years.

 

[gtirard]

Thanks for the update. I respect a company innovating to make our life easier (and keep our backs healthy) but it seems they need to figure out how to do it without them breaking down after only a couple of years.

I agree with the first half of your sentence, but I don't think they can do anything to make robust a concept that is inherently fragile.
I think OP's photos show very well that it's really a structural problem: it's almost impossible to keep this material together firmly with all the vibrations a bass cab has to endure.
If you design a car to beat world records, you want it to be as reliable as possible but it will always be more fragile than a familly car.

I'm sure there are many Talkbass members who have enjoyed their carbon fiber cab without any issue for years and years, they are lucky. But if you want to have the lightest possible cab, you have to accept the risks.

I'm not in the "world record" team anymore, more on the "easy life" team. My cabs are "light enough" => Barefaced.

And if it was easy of even possible to make sturdy and reliable carbon fiber cabs, GR Bass would have figured out by now, and you would probably see other brands making carbon fiber cabs.

Carbon Fiber cabs are not design for easy life, they are like race cars.

 

[JamesGrant]

I have a GR AT410 and it is great but… the factory fittings are shockingly poor. The metal trim and plastic corners are not ‘road worthy’ here’s what Infid to mine a couple of years ago and it’s been great since.
The feet were absolute crap - screwed into foam core. I’ve replaced them with hard wearing nylon skids.
The corners were also terrible - I replaced them all with original ones and they all broke too. So I replaced them with proper hardware (lightweight flight case hardware - the postage and packaging was more than the 8 corners!). I used a resin glue with sets with a bit of elasticity. I had to remove sections of the trim to fit my DIY corners.

I’m surprised that GR used such poor components and thought that screws into foamcore would hold up to real world use.

Anyway - hope this encourages you and provides inspiration. It’s an awesome cab (and now super thanks to my DIY efforts!)

(Really great sound, 1200Watts RMS, 11.5Kg (less than 20lbs) - awesome!)

 

[blastoff]

not all it's cracked up to be. at least its not a submarine

 

[Mr Horse]

not all it's cracked up to be. at least its not a submarine

Too soon, too soon.

 

[Alain Bass]

I reached out to GR and after a little back and forth, they are saying that some of the damage can’t be fixed and offered me a nice deal on a new cab (minus the 12” driver).

Keep the speaker and ask them to send only the box. Could be a deal.

 

[gtirard]

Keep the speaker and ask them to send only the box. Could be a deal.

Or better: keep the speaker and ask them to send only a wooden box.

GR 112H: 10,9 Kg - 24.03 lbs
AT 112H: 6,3 Kg - 13,9 lbs

The wood version is less record-breaking lightweight, but it's still very light, this will make your life easy + peace of mind.
That's what I would do anyway.

Edit: or I would have it repaired, then sell it and buy a Barefaced cab

 

[Guitalia]

That they're willing to offer a deal for a way-out-of-warranty, extensively gigged cabinet to someone who isn't even the first owner is amazing. The vast majority of manufacturers would tell you to pound sand.

 

[Gervais Cote]

If I may ask, do you live in an area where there are big variations of temperature with high humidity in summer and cold and dry conditions in winter ?

High humidity will make pieces of wood getting longer/bigger while very cold temperatures will shrink any material other than wood causing such delaminating.

 

[Gervais Cote]

I should also mention that plastic and metal have different thermal expansion properties, aluminum being the one with the biggest thermal expansion rate.

 

[MCF]

That they're willing to offer a deal for a way-out-of-warranty, extensively gigged cabinet to someone who isn't even the first owner is amazing. The vast majority of manufacturers would tell you to pound sand.

I agree. That’s great on them for offering to do that.

Assuming 250 gigs at a price of $1100 for new ones. That $4.40 a gig. Not to mention practices, rehearsals, etc. Doesn’t sound bad at all to me. Super light weight convenience and good sound costs a premium.

 

[roccobass]

If I may ask, do you live in an area where there are big variations of temperature with high humidity in summer and cold and dry conditions in winter ?

High humidity will make pieces of wood getting longer/bigger while very cold temperatures will shrink any material other than wood causing such delaminating.

I should also mention that plastic and metal have different thermal expansion properties, aluminum being the one with the biggest thermal expansion rate.

Exactly what I was going to mention. Even though his region (Talent, Oregon) isn’t known for humidity fluctuations, sometimes the room where it’s stored may have dampness issues. I know. I used to live in a house that had humidity issues in one room. I was going to ask the OP if the cab showed any signs of previous repairs in those trouble spots.

 

[JazznFunk]

Carbon Fiber is a beautiful thing, and incredibly strong, but once you break that weave it's toast.

 

[matthewbrown]

I have a GR AT410 and it is great but… the factory fittings are shockingly poor. The metal trim and plastic corners are not ‘road worthy’ here’s what Infid to mine a couple of years ago and it’s been great since.
The feet were absolute crap - screwed into foam core. I’ve replaced them with hard wearing nylon skids.
The corners were also terrible - I replaced them all with original ones and they all broke too. So I replaced them with proper hardware (lightweight flight case hardware - the postage and packaging was more than the 8 corners!). I used a resin glue with sets with a bit of elasticity. I had to remove sections of the trim to fit my DIY corners.

I’m surprised that GR used such poor components and thought that screws into foamcore would hold up to real world use.

Anyway - hope this encourages you and provides inspiration. It’s an awesome cab (and now super thanks to my DIY efforts!)

(Really great sound, 1200Watts RMS, 11.5Kg (less than 20lbs) - awesome!)

View attachment 7366099

I'd love to know where you got the corners.

 

[Zooberwerx]

Carbon Fiber is a beautiful thing, and incredibly strong, but once you break that weave it's toast.

Can't tell but did the weave actually break or are we seeing compromise in the interfaces between dissimilar materials? I'm wondering if this is something we can wrestle back into shape with clamps, epoxies (Western Systems), and internal reinforcements & bracing. The velcro grille mount separation is particularly disturbing and may very well be representative of the balance.

We've got tons of boat repair guys here who COULD tackle the project but at a hefty cost. I'd check in with @Bruce Johnson first...not necessarily a cab guy but knows his way around epoxies, glue-ups, TOS, etc.

Riis

 

[JimChjones]

Honestly folks. There is a lot in this thread which is a little less than accurate. One could make carbon fibre cabs that you could stand an elephant on if needed.
To my mind the big challenge with CF cabs is building them down to an acceptable price. The materials can be as solid as you like. You know the sort of thing, cheap, light, strong, pick any two.

As ever, the engineering is a question of compromise and learning. If this is a cab they built five or 6 years ago then its probably not built the way they make the things now. I'd need to see the thing to give a serious opinion on what went wrong, even as an amateur boat builder with carbon, but on the face of it this looks as if it could be a design issue with that particular product as they were making it 5 or 6 years ago. Rubbishing the entire concept because of a failure of one particular implementation isn't really rational thinking. Don't get me wrong, I think there are serious challenges in putting together a roadworthy CF cabinet, but they are mainly about affordability.