Isobaric cab?

[CL400Peavey]

I've always thought it strange that greenboy doesn't list a range of acceptable T-S specs the way BFM does. Not everyone has access to the same speakers, and not everyone needs top of the line either. The 2226 is a perfect match with the Simplexx 15, BFM doesn't mention it specifically because the current $500 USD price is pretty ridiculous.

He doesnt list a range of speakers because the plans are free, so he has not spent time to 1 check suitability of other drivers, 2 work out plans that are suited to multiple drivers. He had a set design goal, that was based around a specific woofer, price point, and ease of build.

Its kind of like asking why Ford doesnt put Hemi or Vortec engines in their vehicles.

 

[spwath]

I've always thought it strange that greenboy doesn't list a range of acceptable T-S specs the way BFM does. Not everyone has access to the same speakers, and not everyone needs top of the line either. The 2226 is a perfect match with the Simplexx 15, BFM doesn't mention it specifically because the current $500 USD price is pretty ridiculous.

And it's worth the 15$ to get the plan instead of making one myself? I was planning on using a midrange driver, not a tweeter.

Also, why not just build one myself using the dimensions from WinISD, and some internal bracing and such?

 

[pie_man_25]

And it's worth the 15$ to get the plan instead of making one myself? I was planning on using a midrange driver, not a tweeter.

Also, why not just build one myself using the dimensions from WinISD, and some internal bracing and such?

Well, you've got the drivers, might as well figure something out, but BFM likes his eminence drivers, and also specializes mostly with horns - which are great for sensitivity and low-distortion, but can be big (though he does mitigate the heavy part with the use of thinner, well-braced plywood and neo drivers).

They're very good designs within their parameters, but IMO if you're using your JBL's, I don't necessarily see much point in spending the $15. BFM designs are kind of like baking recipes - the product is virtually guaranteed to turn out and be great, as long as you follow the recipe, any changes in the recipe will change the product and may not be a positive change.

 

[spwath]

Well, you've got the drivers, might as well figure something out, but BFM likes his eminence drivers, and also specializes mostly with horns - which are great for sensitivity and low-distortion, but can be big (though he does mitigate the heavy part with the use of thinner, well-braced plywood and neo drivers).

They're very good designs within their parameters, but IMO if you're using your JBL's, I don't necessarily see much point in spending the $15. BFM designs are kind of like baking recipes - the product is virtually guaranteed to turn out and be great, as long as you follow the recipe, any changes in the recipe will change the product and may not be a positive change.

Ok, I think I'll try my own design.

I might finish it in a mirrored white finish, like piano black, but white. That would be cool.

 

[Passinwind]

He doesnt list a range of speakers because the plans are free, so he has not spent time to 1 check suitability of other drivers, 2 work out plans that are suited to multiple drivers. He had a set design goal, that was based around a specific woofer, price point, and ease of build.

Its kind of like asking why Ford doesnt put Hemi or Vortec engines in their vehicles.

Yep. For the original 15/6 Dave did manage to find exactly one workable alternative woofer. It cost a lot more money and was/is extremely difficult to source in the US. AFAIK I am the only one to ever try it, and it turns out to work better in a smaller cab format anyway, as expected. Personally, I find it strange that people want more of something for nothing, like eight free lunches isn't already enough. But vive la difference.

 

[BadExample]

I would consider at least testing those drivers without the crossover and midrange. That is if you don't require Hi(er) Fidelity for modern, slap or something. My 15 is rated 20-2.5KHz, about the same, and reproduces open low B up to the highest octave G very nicely.

 

[spwath]

I would consider at least testing those drivers without the crossover and midrange. That is if you don't require Hi(er) Fidelity for modern, slap or something. My 15 is rated 20-2.5KHz, about the same, and reproduces open low B up to the highest octave G very nicely.

The JBL's are only rated to 1.2k. That doesnt seem high enought at all.

 

[Passinwind]

The JBL's are only rated to 1.2k. That doesnt seem high enought at all.

Yep, 2226 drivers used standalone for bass guitar are not really happening for most people, IME. Here's an old thread addressing that and some other factors that may be worth considering: JBL 2226 for bass

 

[40Hz]

I've always thought it strange that greenboy doesn't list a range of acceptable T-S specs the way BFM does. Not everyone has access to the same speakers, and not everyone needs top of the line either. The 2226 is a perfect match with the Simplexx 15, BFM doesn't mention it specifically because the current $500 USD price is pretty ridiculous.

I think a lot of it has to do with how the crossover is designed. There's some subtle tweaking going on there. They also said they were out to develop a perfectly optimized cabinet to produce a certain sound quality. So I'm guessing the tweaks also extended to the cabinet metrics as well, hence the very specific speakers they use in them.

Having a heard a few of their commercial Fearless models I think they succeeded rather admirably.

Greenboys are the first cabs I've heard that succeeded in bumping Bag End off my top spot. But to your point, they are expensive and unapologetically top line. And I don't play out enough to justify getting an F112 much as I'd love to.

 

[ajschnitzelbank]

Can't think of a bigger waste of time and effort for no real increase in performance, plus the need for a mid driver, crossover and the size continues to grow...

Ok, I'll just do a smaller cab then.
Anything will be better than my horn loaded 120lb Yamaha pa cab.
90l would be a nice size.

I dunno, man. Sometimes doing crazy oddball stuff is fun. Throw the rulebook out. Use what ya got to build something no one else is without a good reason why. Wow, that sounds sarcastic, but I am serious. Great stuff has been made by people who are doing things in an impractical way that doesn't work well on paper. Think of the humble Porsche 911: the engine is mounted with a bunch of weight behind the rear axle. Nobody seems to think that's a great idea. But to me, the 911 is awesome!

 

[ajschnitzelbank]

Though the advice here to not attempt isobaric is good. I wouldn't. But I admire someone who would be willing to try it.

 

[agedhorse]

I dunno, man. Sometimes doing crazy oddball stuff is fun. Throw the rulebook out. Use what ya got to build something no one else is without a good reason why. Wow, that sounds sarcastic, but I am serious. Great stuff has been made by people who are doing things in an impractical way that doesn't work well on paper. Think of the humble Porsche 911: the engine is mounted with a bunch of weight behind the rear axle. Nobody seems to think that's a great idea. But to me, the 911 is awesome!

It helps to understand why it's not a very good approach... almost no benefit and plenty of issues, none of which exploit the basic good properties of that driver.

(without trying to sound sarcastic) If you want to try something new, understand how the principles work so that you have some kind of positive odds to work with. Otherwise, you might just be reinventing yest another "square wheel".

 

[ajschnitzelbank]

It helps to understand why it's not a very good approach... almost no benefit and plenty of issues, none of which exploit the basic good properties of that driver.

(without trying to sound sarcastic) If you want to try something new, understand how the principles work so that you have some kind of positive odds to work with. Otherwise, you might just be reinventing yest another "square wheel".

May invent another square wheel. Wow, good point! Guess I'm just feeling vicariously adventurous today. Hah!

 

[gumtown]

If you must re-invent the wheel, remember..

Octagonal wheels are less bumpy than square wheels.

 

[agedhorse]

I'm all about developing new technologies... In fact it's my day job. It's helpful to look around to determine what's been done before, and the pros/cons of that work so that you don't re-prove other folk's failures!

 

[abarson]

I don't assume to know the OP's level of experience with building cabs. Myself, I've only built one of my own whacked out design, with disappointing results. It taught me how much I don't know, and how much there is to learn from what works first. Only then can you springboard off of that knowledge into something that deviates from the norm. So then it comes down to whether you want to build something of verified results that you can turn around and use within a reasonable amount of time, or if you have the luxury and curiosity to turn a single project into ongoing research, refining and building off of mistakes made along the way. But a good grasp of what and how you want to accomplish something is really essential.

Oh, and Ferdinand Porsche was an automotive genius and had a deep enough understanding of physics, mechanics and electricity to be innovative and groundbreaking.

 

[BadExample]

The JBL's are only rated to 1.2k. That doesnt seem high enought at all.

Sorry I thought it went to 2.5K.

 

[agedhorse]

Sorry I thought it went to 2.5K.

On axis the response is pretty close to 2.5kHz at -6dB, but still this is generally too dark for many players. Throwing it into an isobaric design and I could see the top end being limited to a few hundred Hz depending on the specific orientation.

 

[BadExample]

If you must re-invent the wheel, remember..

Octagonal wheels are less bumpy than square wheels.

That is making an assumption of what the goals of the OP on talkwheel.com are.



You actually can make any shape of wheel run smoothly on the right "road." It just so happens that at they least try to make roads flatish.

 

[BadExample]

On axis the response is pretty close to 2.5kHz at -6dB, but still this is generally too dark for many players. Throwing it into an isobaric design and I could see the top end being limited to a few hundred Hz depending on the specific orientation.

I need to not read specs on my phone.