Composite Nidacore Fearful 15/6/1 Build

[Mr. Foxen]

Had to laugh the other day when someone said their 55-pound tube head was vibrating off their 2-driver Emperor cab. There's no excuse for that design/build flaw.

That sor tof thing is a boast/point of honour in Emperor cab toting Doom circles, where people need to quantify their loud to boast on the internet. People were all impressed at the update on my drone band saying '3rd vintage valve head exploded', then started asking why we hadn't recorded any new music.

 

[jlepre]

Any updates? Photos would be GREAT!

 

[greenboy]

That sort of thing is a boast/point of honour in Emperor cab toting Doom circles, where people need to quantify their loud to boast on the internet. People were all impressed at the update on my drone band saying '3rd vintage valve head exploded', then started asking why we hadn't recorded any new music.

Yeah. If I was playing doom I'd want to have at least a few 1515/66. And the best highest-value earplugs money can buy. And I'd brag about NOT having cabs wihtout adequate bracing. Not that people would hear.

They'd be deafened by that point.

 

[Mr. Foxen]

Yeah. If I was playing doom I'd want to have at least a few 1515/66. And the best highest-value earplugs money can buy. And I'd brag about NOT having cabs wihtout adequate bracing. Not that people would hear.

They'd be deafened by that point.

Are those cabs happy with wrecked old valve amps screaming their guts out? The extra top might end up being disagreeable, and those amps ain't rich in EQ options. It has kind of been putting me off a build, because a 200w valve heads + uber high excursion woofers seems to not be appropriate.

 

[greenboy]

Are those cabs happy with wrecked old valve amps screaming their guts out?

Sounds marvelous! And addicting! At least with 15/6, or 12/6, or stacked with mid drivers in between the woofers like this: [Invalid or Expired Link Removed]

With an old mod'd Fender bassman I can barely stand to go to 10 on the master, but that's because of the loudness in a smaller space. The tone itself is incredible - if not quite as flexible as I've enjoyed with something with a switchable center Baxandall (ala Ampeg), which cops the kind of tones I'm more used to using the V-Bass (ie more adjustable to various types of band mixes).

With 1515/66 I'd want to be offside more, and further back.

I could gig with these and a tube head night after night and would always be jonesing for enough tunes variety to be able to get various shades of nasty or grungy. I'd definitely want to add an octave-up doubling pedal though - because guitar range ultra drives and more bluesy overdrives alike sound glorious through that mid driver!

 

[Robby Hoinsky]

I am reading this, and I have a slight concern. Being polypropolene I think epoxy is not the correct thing to use in bonding it. I beleive you need a polyster resin...not epoxy. That being said, and having done some composites before I have a couple other thoughts. First, when making the fillets on the inside joints one might wish to consider an amendment to the resin. Something like a chopped carbon fiber, chopped glass, or kevlar pulp. Most resins by themselves are brittle, and addign an amendment to them toughens them significantly.

Secondly, I am surpised that he did not consider using a nomex cored fiberglass panel. Epoxy will adhere to this, and epoxy is generally better than polyester resin in temrs of strength.

Actually epoxy or polyester resin with a thickening agent would work very well bonding the nidacore. The polypropylene is just in the core, the outer panels are f'glass with poly resin, which epoxy bonds to very well.

I'm not using either though, I'm using PL premium adhesive for bonding the panels. I used it on a BFM Titan 39 that I load in and out of a gig every saturday and it is holding up with no signs of failure. Not only does it bond well to the fiberglass, but it expands into the honeycomb core and makes a very good physical bond.

Any updates? Photos would be GREAT!

I pulled apart the test panel a bit prematurely. The shop where this is being built is only heated when we're working, and being under 10 degrees outside, inside it didn't cure fully. So the test panel has been remade and placed in a warmer place. I don't anticipate any problems with adhesion, but I'm not going to risk it until I can test this panel tomorrow night after a full 48 hours of curing.

Once I get started building, it should come together pretty quickly. Pictures by this weekend, I promise.

Robby

 

[Robby Hoinsky]

Yeah. If I was playing doom I'd want to have at least a few 1515/66. And the best highest-value earplugs money can buy. And I'd brag about NOT having cabs wihtout adequate bracing. Not that people would hear.

They'd be deafened by that point.

GB, how would inset 90 degree handles affect the tuning of a 1515/66? Would it be necessary to build it a bit deeper to maintain airspace? How about for smaller cabs, like a 12/6 or 15/6?

Robby

 

[greenboy]

GB, how would inset 90 degree handles affect the tuning of a 1515/66? Would it be necessary to build it a bit deeper to maintain airspace? How about for smaller cabs, like a 12/6 or 15/6?

Hey Robby,

Sorry I couldn't answer last night. Social life, whot? ; }

When you say 90° handles is this what you refer to?: [Invalid or Expired Link Removed] ...If so, the 1515/66 has allowed for them without retuning.

Without retuning the 15/6 allows for a High Frequency section anad this type of handle: [Invalid or Expired Link Removed]. If right angle handles were added I'd retune a little by adding some shelf. Unless the player is tuning lower than I am, which is A0/G0 [http://greenboy.us/fEARful/frequencytables.htm#fundamental] on a drop tuner, I wouldn't add box size. Are yo considering a tilt-back handle or two in addition to standard medium cup handles for 15/6?

hey deb, better say howdy to you once in awhile too : } - you guys might want to check this page below out, and then talk about what type of LF profile you are shooting for. Ask away once you've kinda digested some of this: [Invalid or Expired Link Removed]

 

[Robby Hoinsky]

Hey Robby,

Sorry I couldn't answer last night. Social life, whot? ; }

When you say 90° handles is this what you refer to?: [Invalid or Expired Link Removed] ...If so, the 1515/66 has allowed for them without retuning.

Without retuning the 15/6 allows for a High Frequency section anad this type of handle: [Invalid or Expired Link Removed]. If right angle handles were added I'd retune a little by adding some shelf. Unless the player is tuning lower than I am, which is A0/G0 [http://greenboy.us/fEARful/frequencytables.htm#fundamental] on a drop tuner, I wouldn't add box size. Are yo considering a tilt-back handle or two in addition to standard medium cup handles for 15/6?

Those are the handles I'm talking about. Not for the 15/6 but for a 1515/66. I figured that the airspace in the larger cabinet would be flexible enough for them, but didn't think that the smaller cab would be. I can't see it making sense on the smaller cab anyway, given how low to the ground they are. Unless it was a stack with the bottom having casters and the top having handles, then some butterfly latches to make them easily transportable together.

So in that case, it would be better to extend the shelf than making the box larger?

Robby

 

[greenboy]

As I said, Robbie, those handles are figured into the 1515/66 already along with a pair of medium cup handles on the side. And indeed, as you surmised, less compensation was required in larger cabs. It was easy to do all that in the 1515/66 size I desired and not have to add even a 1/8" to the shelf. The 1212/6 is compensated for one tilt-back/right angle handle and a pair of medium cups. you don't need to add shelf depth. Unless you want to for a different rolloff slope.

Actually all of these have room for plate amps too without losing my desired LF target, just by adding a little shelf depth! 15/6 gained some internal space in revision 2 plans to allow this but all the others already were there.

I just trotted out the shelf extension page in case you guys hadn't seen that yet.

 

[deb]

Hey greenboy, thanks for the links and suggestions. These are always greatly appreciated! I do enjoy reading up on the various fEARful options, and thoughts underlying their implementation.

I'm strictly playing 4 stringers these days. The handle options relate to another project, I think. Unless I'm getting a bonus package for being the guinea pig.

Tonight is the Phase II PL curing test. Robby's using warmer temperature, 48 hours cure time. We're expecting great results. But, with all prototypes, much tinkering is to be expected and, of course, the build time will be lengthier. So, patience grasshoppers! As soon as I know, I'll update this thread.

Ken: thanks for your offer to test the cab. I think it would be useful for the community to listen to the nidacore fEARful 15/6/1 and compare against your other offerings. That way the basses, amps, recording devices, playing style, etc. will be kept consistent.

 

[bigfatbass]

Nidacore is nothing like what Flite uses. Their composite is layers of wood and foam. Strong enough, but a bit plinky acoustically, and not the most dent resistant stuff. I would spray it with duratex or similar if I was working with it, and it seems that to brace it enough to be neutral, you would be adding back the weight you saved in the first place.

Mine are older, I'm curious to hear what the new designs sound like. I'm even more curious to see how the nidacore rig of doom turns out!

 

[NickyBass]

The handle options relate to another project, I think.

Those are for a 1515/66 nidacore cabinet that Robby is building for me! I've been lurking in the fEarful threads since the begining and really like the concept. Now that it is possible to have a 50ish lb 2x15 cabinet, it seemed like the perfect time to jump on it.

Are there any updates on your cabinet?

 

[jlepre]

I believe it was said earlier that they would have something to show this weekend. I can't wait to see as well.

 

[greenboy]

Nidacore is nothing like what Flite uses. Their composite is layers of wood and foam. Strong enough, but a bit plinky acoustically, and not the most dent resistant stuff.

Yep, for the last several generations Flite has used what's called foamcore - veneered building foam. Even with "normal" woofers rather than the incredible bruisers found in fEARfuls, it only works good on small panel areas. And Flite never braces, so they are wasting a lot of acoustic output/energy and focus because of it. With a larger panel enclosure and a REAL woofer, that approach would be more than negligent - it would be madness.

10 or more years ago and at least one owner ago they used a honeycomb composite but that too was nothing like Nida-Core in terms of structural integrity.

 

[deb]

The Nidacore + PL premium glue-up test was a success!! Seems that the PL adhesive is curing well at the higher temperature and the next phase of the build is ready to go ...

Robby mentioned the Nidacore panels are extremely stiff. Bracing doesn't seem to add to the stiffness of the panels and is therefore probably not necessary. Nevertheless, it's done and we're sticking to the plans.

Braces glued to cut panels. Shelf port on left.

Assembled mid-driver enclosure:

Dry fitting of panels:

Bonus naughty peek through the woofer cutout:

Robby's gone ahead and ordered the finishing materials and cabinet hardware I've requested. Drivers and crossover components are being bought from Leland at speaker hardware. Looking forward to the next phase! Thanks Robby!

deb

 

[Chef]

sweet!!!

 

[WCunha]

Looks great! How much does it weigh?

 

[deb]

As much as a bag of feathers.

Seriously, we're not getting into that this early in the build. When it's done I'll measure the weight and inform everyone. Robby estimates that the empty cabinet will weight about 10-12 lbs.

 

[MultiScaleMale]

Very interesting!