NCabsD: Stacking on top of a fEARful

[lucas303]

Yesterday I finished my fEARful 15 Sub build. If you want to read the build thread, here's the link: Build thread: fEARful 15 sub

I've really wanted a rig that could push some low frequencies, and after doing a ton of reading online I came to two conclusions: (1) getting any serious power below 40 Hz would be difficult at best; and (2) for getting anything approaching serious power at 40 Hz a fEARful was the most cost-efficient option (cost-efficient as long as I'm not accounting for my own time/labor, that is). I'd never built a cab before, and the sub seemed like a good place to start because the enclosure is relatively straightforward and it's just the single speaker to deal with.

My plan from the start was to pair the 15 Sub with a cab dedicated for midrange/highs. Since some of my favorite bass players used guitar cabs for that purpose (in one form or another, depending on the player), I was drawn to the idea of using a guitar cab. I considered building one, but then lo and behold I found a cheap 212 guitar cab (without speakers) on Craigslist. So while I was in the last week or two of the fEARful build I finished up the guitar cab as well. I was also interested in using a guitar cab simply because I have a natural tendency to want to do things a little bit different.

On to the pictures:





I haven't cranked this yet, but so far I'm loving the sound. My low A string sounds massive through the sub, and the 212 is more than enough for the high end. I don't think I'll ever push this guitar cab to its full capability. Right now I've got the crossover set at 280 Hz. There's no real science behind that decision, I just adjusted it by ear. I'm sure I'll tweak it more as time goes on. (And, FWIW, I have a HPF on the sub set at 40 Hz.) Also, for now the guitar cab volume is set at -4 on the power amp, with the sub volume set at 0. I wouldn't be surprised if that gets adjusted the first time I really crank this rig.

The guitar cab has Celestion G12T Hot 100s (8 ohm) wired in series. I put new damping material in it (leftover acoustic foam from my fEARful), and wired it with a Speakon input jack instead of 1/4". The fEARful has the speaker it was designed for.

I think that about does it. Hopefully someday soon I'll get to play this rig with a band and really hear what it's capable of. Until then, I'll just be rocking out at home as loud as the cats will tolerate (which isn't very loud).

 

[Flamingo21]

It looks very impressive. You obviously know a thing or two about woodworking.

I suspect I should look into your build thread before asking any questions.

 

[lucas303]

It looks very impressive. You obviously know a thing or two about woodworking.

I assure you I don't, and that's not just false modesty. I genuinely don't have any woodworking skills. That should say something about how accessible a build like this is.

 

[Flamingo21]

Frankly, until I read you build thread I didn't even realize it's a kit.

 

[Flamingo21]

Hmmm... I actually do have woodworking skills. Also, I'll need an extra cab at some point. This is beginning to look tempting.

 

[Bill Whitehurst]

Sounds like a practical crossover freq for what you are doing.

 

[singlemalt]

Nice job on the build thread! You did great with minimal tools, and lots of patience. Good sequencing and creative problem solving on the issues that always arise in DIY.

Cool rig you've created.

Thing with a fEarfuls is.... you can't build just one. It's too much fun.

And now you know someone with a table saw. A cheap router, a few more clamps...next thing you know you've got gas for tools. A biscuit jointer is my favorite shop toy, maybe $120. Always good to have a small air compressor in the garage (flats happen) and maybe a narrow crown stapler....

12/6 cube is a cool brain twister.

 

[lucas303]

Nice job on the build thread! You did great with minimal tools, and lots of patience. Good sequencing and creative problem solving on the issues that always arise in DIY.

Cool rig you've created.

Thing with a fEarfuls is.... you can't build just one. It's too much fun.

And now you know someone with a table saw. A cheap router, a few more clamps...next thing you know you've got gas for tools. A biscuit jointer is my favorite shop toy, maybe $120. Always good to have a small air compressor in the garage (flats happen) and maybe a narrow crown stapler....

12/6 cube is a cool brain twister.

Thanks for the kind words. Though I don't have plans for another build, if anything I'd be tempted to make another 15 Sub so that if and when I want to pump out some serious low frequencies I could really rattle the walls. I don't see a need for that anytime soon though.

 

[bassman10096]

I stack a fearFul 15/6 on a featFul 15 sub. Fantastically loud, clearest highs and mids I've ever experienced. Wow. A 12-based top cab would be interesting too. But the 6" mid speaker is the secret sauce - it projects the highs and high mids so well. I chose not to build with a tweeter and haven't missed any high end at all.

 

[Redbrangus]

What's the concept behind running the 12s in series...got too much power? Also, is the guitar cab open-backed? (I'm guessing not, since you put foam in it, but just checking.)

What color are you thinking of for the top cab? Something contrasting...maybe Fiesta Red?

 

[lucas303]

What's the concept behind running the 12s in series...got too much power? Also, is the guitar cab open-backed? (I'm guessing not, since you put foam in it, but just checking.

What color are you thinking of for the top cab? Something contrasting...maybe Fiesta Red?

Yeah I have them in series solely because of the amount of power this amp puts out. A 112 would likely be more than enough to compliment the 15 Sub, but then the 112 would be getting way too much power from the amp. It's a closed-back cab.

I'm not planning on painting or refinishing the guitar cab in the immediate future. If I do it would probably be in the same green. But in all likelihood I may never feel like doing that.

 

[Passinwind]

I stack a fearFul 15/6 on a featFul 15 sub. Fantastically loud, clearest highs and mids I've ever experienced. Wow. A 12-based top cab would be interesting too. But the 6" mid speaker is the secret sauce - it projects the highs and high mids so well. I chose not to build with a tweeter and haven't missed any high end at all.

I really missed having a tweeter with my 12/6 build and my EUB and fretless basses. For me a really good tweeter is the secret sauce, not the 6. Vive la difference!

But I love this thread and I do have a 112 or maybe 212 cab in the works myself to sit next to my 15/6/1 fARFul cab or on top of just the 15. @lucas303 : don't discount the possibility of doing a fEARful headcase style top box at some point if you decide to dabble in FRFR applications. I've done five so far, some close to Dave's design and some quite different. IME lots of different approaches can work pretty well.

 

[lucas303]

But I love this thread and I do have a 112 or maybe 212 cab in the works myself to sit next to my 15/6/1 fARFul cab or on top of just the 15. @lucas303 : don't discount the possibility of doing a fEARful headcase style top box at some point if you decide to dabble in FRFR applications. I've done five so far, some close to Dave's design and some quite different. IME lots of different approaches can work pretty well.

I definitely wouldn't rule it out. I saw it mentioned here and there when researching this, but didn't see any flat packs or plans. Maybe I simply missed something? It's certainly something I'd like to investigate.

 

[Passinwind]

I definitely wouldn't rule it out. I saw it mentioned here and there when researching this, but didn't see any flat packs or plans. Maybe I simply missed something? It's certainly something I'd like to investigate.

For those who are registered on Dave's forum: [Invalid or Expired Link Removed]. He simply adapted an existing rack case.

Edit: not sure if this requires login, but it's fairly thorough: [Invalid or Expired Link Removed]

AFAIK there were never any official plans. At least a few other TBers have built their own though. Since my photo link in the Greenboy Forum is now hosed you can see some of mine here:

Passinwind DIY Cabs

The one with the horn loaded six is my favorite and it's my practice rig at home. Once I get my DIY 100 watt tube amp finished I'll do another round or two of experiments, but I'll need a dedicated guitar cab anyway and something closer to what you're doing may easily be the call. For bass I am looking at a 700 watt clean channel and then a complementary separate 100 watt rig for slide bass that can be either clean or dirty. Maybe something like a 12/4/4, not really sure just yet.

 

[lucas303]

For those who are registered on Dave's forum: [Invalid or Expired Link Removed]. He simply adapted an existing rack case.

AFAIK there were never any official plans. At least a few other TBers have built their own though. Since my photo link in the Greenboy Forum is now hosed you can see some of mine here:

Passinwind DIY Cabs

The one with the horn loaded six is my favorite and it's my practice rig at home. Once I get my DIY 100 watt tube amp finished I'll do another round or two of experiments, but I'll need a dedicated guitar cab anyway and something closer to what you're doing may easily be the call. For bass I am looking at a 700 watt clean channel and then a complementary separate 100 watt rig for slide bass that can be either clean or dirty. Maybe something like a 12/4/4, not really sure just yet.

I love the look of yours! I wouldn't know where to start with figuring out the volume of the box needed, chambers for the drivers, etc though.

Just out of curiosity, has anyone considered using BMRs for the midrange/highs? For reference: BMRs They don't appear to put out a ton of decibels, but maybe some sort of array of them could compensate for that? The frequency response is really flat and also smooth off axis.

 

[Passinwind]

I love the look of yours! I wouldn't know where to start with figuring out the volume of the box needed, chambers for the drivers, etc though.

You can just go with the smallest practical volume that will enclose the 6 and stuff like crazy, as shown in Dave's links. I added a second link that should help a bit.

I'm doing a matching natural finish head case for the new amp, here's the general idea:

My luthier friend has done a few different front panel fascia testers and the wood for the final version just came in a few days ago. I'm still getting up to speed on laser engraving but it sure is fun to play with!

 

[cableguy]

Looks great! That rack looks like it wouldn't take much to topple though. I preferred my 12/6 on my 15/sub when I had it, though I'm sure yours sounds great. The thing I liked about my 15/sub was it was more punch than low end boom if that makes sense. I'm sure you HPF would help with that as well. I'm not sure of your signal chain, but that top cab is screaming for some distortion to be played through it.

 

[lucas303]

I'm not sure of your signal chain, but that top cab is screaming for some distortion to be played through it.

I've got two Ibanez PD7s running at the moment, so I'm with you there!

 

[Wasnex]

Here is the frequency response plot of the Hot 100s.

Not too bad, although the sound might have a lot of gank and fret rattle without corrective EQ.

As long as you are crossing them over at a relatively high frequency you have plenty of power handling. I believe running them in series can magnify resonances in the frequency response. So I suggest trying parallel if you will use the rig exclusively for bass. If you will use the cab for guitar, consider the output impedance of your guitar amp.

I would experiment with a crossover between about 150hz and 400hz.

Regarding whether a fEARful 15/6 or fEARful headcase would sound better. That is going to be entirely subjective.

If you were to run a full fEARful rig, I would suggest abandoning the biamp idea and going with the fEARful crossover. The disadvantage with biamping is your crossover is generic (also probably fairly low quality) and not tailored to the characteristics of the design. In contrast, Dave Green put quite a bit of engineering effort into building crossovers that would work well with the fEARful designs.

If you decide to use a tweeter, the later True 3-Way design will give the most accurate response. In the original design, the mid was allowed to run full range and the tweeter was brought in to compliment the natural rolloff of the mid driver. With the True 3-Way the mid has LPF section, so there is a true (full) crossover between the mid and tweeter.

I have biamped bass rigs with PA cabs running as the mid-high pack, and I have also used JBL E120s in open back and closed back cabs. With a bit of tweaking, I have gotten pretty good results from all.

In particular, the thing I like about this design is the vertical array. This particular guitar cab splays the top driver back in an attempt to widen the vertical dispersion patter. The results will not be perfect, but it will probably be an improvement over a straight cab. So although I agree that a single 12" would be plenty, there are potential advantages to using two drivers.

IMHO, this is a great opportunity to have some fun and perhaps learn a thing or two. It's probably not going to be the absolute best sounding rig in the world, but it should sound pretty darn good.

 

[lucas303]

Here is the frequency response plot of the Hot 100s.

View attachment 4072197

Not too bad, although the sound might have a lot of gank and fret rattle without corrective EQ.

As long as you are crossing them over at a relatively high frequency you have plenty of power handling. I believe running them in series can magnify resonances in the frequency response. So I suggest trying parallel if you will use the rig exclusively for bass. If you will use the cab for guitar, consider the output impedance of your guitar amp.

I would experiment with a crossover between about 150hz and 400hz.

Regarding whether a fEARful 15/6 or fEARful headcase would sound better. That is going to be entirely subjective.

If you were to run a full fEARful rig, I would suggest abandoning the biamp idea and going with the fEARful crossover. The disadvantage with biamping is your crossover is generic (also probably fairly low quality) and not tailored to the characteristics of the design. In contrast, Dave Green put quite a bit of engineering effort into building crossovers that would work well with the fEARful designs.

If you decide to use a tweeter, the later True 3-Way design will give the most accurate response. In the original design, the mid was allowed to run full range and the tweeter was brought in to compliment the natural rolloff of the mid driver. With the True 3-Way the mid has LPF section, so there is a true (full) crossover between the mid and tweeter.

I have biamped bass rigs with PA cabs running as the mid-high pack, and I have also used JBL E120s in open back and closed back cabs. With a bit of tweaking, I have gotten pretty good results from all.

In particular, the thing I like about this design is the vertical array. This particular guitar cab splays the top driver back in an attempt to widen the vertical dispersion patter. The results will not be perfect, but it will probably be an improvement over a straight cab. So although I agree that a single 12" would be plenty, there are potential advantages to using two drivers.

IMHO, this is a great opportunity to have some fun and perhaps learn a thing or two. It's probably not going to be the absolute best sounding rig in the world, but it should sound pretty darn good.

Thanks for your thoughtful comments. I'll probably come back to this thread multiple times to try to fully digest the sort of insights provided by you, @Passinwind and everyone else.