is this too much volume??? speaker enclosure.

[Prana Ferox]

The 12A-2 is the current model, the original 12a has been out of production since 2008 or so.

Go here and click on manuals & resources: Home

(I'd say go straight to Eminence but their site isn't loading tonight for whatever reason.)

 

[bon viesta]

The 12A-2 is the current model, the original 12a has been out of production since 2008 or so.

Go here and click on manuals & resources: Home

(I'd say go straight to Eminence but their site isn't loading tonight for whatever reason.)

well the places i’ve looked and found those specs are from 12a betas that are in stock!! here’s a site: Invalid Link Removed unless they’re all flubbing their copy and paste specifications, i feel inclined to believe that these places are selling speakers with those specs. your specs are the first i’ve seen of those numbers, though please give me all the information i need to not have any doubt, because i don’t want to have any.

 

[bon viesta]

here’s where i originally found the specs

 

[Chickenwheels]

When I was in my teens I didn’t ask questions...I just went for it lol! I went through a pile of janky setups, blew up some stuff, had a blast. Just got to
follow your heart and have fun.
Having said that, if you want to DIY, check out Bill Fitzmaurice designs. They’ve done all the maths so you can just do the fun stuff.
P.S. drivers are expensive. A quality mid-bass 15” is vastly superior to and more economical to than 4 12” drivers in a huge box. 1 or 2 12” drivers in a properly designed cabinet is more than ample for most gigging musicians.

 

[lug]

Don't listen to these naysayers! I say build this!!!!

 

[Prana Ferox]

Adorama is a camera store, good place to get lenses but I wouldn't depend on them for correct speaker documentation.

In your linked doc, it say ' suitable for... Bass guitar as a woofer in a vented enclosure, also works well for PA in a sealed enclosure." Generally woofer ( as opposed to full-range) means you have a midrange or tweeter giving some high end frequency output. The PA application assumes subs or bass bins handling <120hz as the sealed cab rollout makes integration simpler.

 

[agedhorse]

When I started, I did study as many sources as possible BUT access to GOOD information was difficult as it was still very much the HI-FI hobbiest era. My father was an EE (I followed in his footsteps), my grandfather was an ME, and I was surrounded by a lot of study, learn, study, experiment on what you have been studying and learn some more. I took electronics in high school, more or less a waste of time as there wasn't much learning involved, but I did study and built kits where I could be successful and learn.

There are so many more ways to learn now, access to information is unbelievably easy compared with the good ol days when we relied on data books and spec sheets that had to be MAILED to us, sometimes we had to pay for data sheets and application notes. An engineering education forces you to learn math, to learn basic principles, methods of experimentation so that a project can proceed step by step with each step being an opportunity to learn without wild ass guessing, without blindly believing folks who don't know what they are talking about (good life skill by the way), and build a foundation for learning more.

You also might spend some time on this forum studying what we have to say about these topics. There are some very smart folks here who have a track record of good advice and information. These are the folks you want to learn from, not the knuckleheads who posts their random theories that they themselves don't understand. (another good life skill to learn). Some of us have been working in this industry for a very long time, and some of us have also been designing for both the pro audio and musical instrument industries (you can tell even if they don't disclose the details of their work).

 

[abarson]

US Speakers is more reputable than Adorama, and you can tap into their expertise for advice on your project. They also provide full Thiele-Small parameters that you need when doing your design. Granted, they are a few dollars more than Adorama, but you're dealing with dedicated professionals at USS. It's likely they can make a recommendation more appropriate for a 412 sealed cabinet than the Beta-12A.

https://usspeaker.com/homepage.htm

 

[agedhorse]

Another life lesson... sometimes it's worth spending more to get better service, accurate information, a better quality product, etc.

 

[spatters]

Speaking as someone who was once a teenage hobbyist, if you aren't at least plugging numbers from Eminence's website and spec sheets into WinISD, you're throwing away a goldmine of information that is available to you with literal minutes of work.

I get that you want something that looks like a classic slant 4x12! You can make that work, and even make it sound great (the slanted upper speakers will help you hear yourself)...but it'll have to be deeper than a guitar 4x12 in order to get the internal volume you need.

 

[Johnny Fingers]

When I was 12 I tried to build a copy of a Dual Showman cabinet with 2x15” Jensen speakers.
It sounded ok but looked pretty rough. It ended up getting burned as firewood and the speakers were used elsewhere, but it was a step up from the crystal radio set a few years earlier.
About 20 years ago I had a couple of EV 15” speakers so I made a couple of bottom ported cabinets for them but they ended up sounding flat and mid-rangey. After a stint in the living room under my JBLs they got sold at a garage sale along with two huge empty 18” subwoofers which weighed a ton.
Whimsical projects for sure, but not a complete waste of time.
My dad was an aeronautical engineer and could design or build anything, but couldn’t sing or play a note. Too bad he bailed out on us or I might not be all thumbs today.

 

[byacey]

When I was 12 I tried to build a copy of a Dual Showman cabinet with 2x15” Jensen speakers.
It sounded ok but looked pretty rough. It ended up getting burned as firewood and the speakers were used elsewhere, but it was a step up from the crystal radio set a few years earlier.
About 20 years ago I had a couple of EV 15” speakers so I made a couple of bottom ported cabinets for them but they ended up sounding flat and mid-rangey. After a stint in the living room under my JBLs they got sold at a garage sale along with two huge empty 18” subwoofers which weighed a ton.
Whimsical projects for sure, but not a complete waste of time.
My dad was an aeronautical engineer and could design or build anything, but couldn’t sing or play a note. Too bad he bailed out on us or I might not be all thumbs today.

Any project that you undertake and learn something from is not a waste of time. Too many people are self-defeatist saying "I could never do that."

To that I say, "You don't know what you're capable of, until you try." I believe that there are many people walking around with natural talents that they never discover, for lack of trying.

 

[bon viesta]

what about basslite speakers??? i’m willing to put more money into a project if it means the project will be worthwhile in the end. i’ve seen a bunch of the threads about how people with boxes that have even less volume than i do put basslite speakers into their cabinets and it sounded pretty great.

 

[lark_z]

Ignore the naysayers, listen to the inner voice pushing you. Ask the elders for advice. It'll all work out.

 

[chadds]

Too much volume? Might not be enough volume. I can't hear it yet.

 

[bon viesta]

i see the irony of the thread title!!! in retrospect i really let my ignorance hang out, but the idiot has gotta ask questions before he becomes a not-idiot.

 

[Redbrangus]

Just to be clear, this cab definitely WILL be sub-divided into two independent sub-chambers, right? I'm asking because an enclosure like that wouldn't seem to need the previously described 2x4 brace running from baffle to back.

I also want to confirm that this cabinet design app that you're using -- the one that uses the exterior dimensions -- has the function of allowing for the baffle set-back distance. What value are you using for this number?

 

[bon viesta]

Just to be clear, this cab definitely WILL be sub-divided into two independent sub-chambers, right? I'm asking because an enclosure like that wouldn't seem to need the previously described 2x4 brace running from baffle to back.

I also want to confirm that this cabinet design app that you're using -- the one that uses the exterior dimensions -- has the function of allowing for the baffle set-back distance. What value are you using for this number?

hahaha, it’s definitely a stretch to call it a “design app”. man you guys give me too much credit! it’s a simple calculator function on a site called “box wizard”. just look up “box wizard volume calculator” and you should find it. if you’re talking about how the speakers amount of volume is different than simply the inside of a cabinet shaped box (with the right thickness) because of the way the baffles have the speakers further back into the cabinet, then that has…. not been accounted for. i suppose i can try to estimate the distance between the cabinets exterior and where the grill cloth is, but all in all it shouldn’t set back the volume too much. i’ll be honest you guys, i’m starting to think back to using a bassman cabinet instead because, contrary to the thread i made where i put the head cabinets dimensions in the post by accident and led many to believe i wanted to put two 12 inch speakers into a blackface tube head, the volume per driver in that cabinet is ~ 1.7 cubic feet, a much better deal than what i’m working with here. and it’s less expensive of a project, AND it’s more portable.

 

[bon viesta]

and as for the dividing… i don’t think so. on the picture, you can see a board running vertically down the middle, but it doesn’t take up the entire cabinet and it seems to just be a sort of “half divider” between the two sets of speakers. it may be more accentuated when the back panel is screwed in. also i thought that back running little 2x4 board was sort of a way to brace the cabinet and “raise the resonant frequency” by pushing against the back of the cabinet when you screw in the back panel.

 

[Redbrangus]

if you’re talking about how the speakers amount of volume is different than simply the inside of a cabinet shaped box (with the right thickness) because of the way the baffles have the speakers further back into the cabinet, then that has…. not been accounted for.

Yes, I am talking about the distance the baffle is recessed into the cab's interior. This is much more important to allow for than the niggly bits like a 2x4 brace. If the interior is all one, un-subdivided chamber, then all this jockeying of numbers about the upper and lower parts of the cab aren't relevant, or even valid; just divide the overall chamber volume by 4, as was previously stated. [Post #4]

I'm going to encourage you in your reconsideration of this 412 project, if for no other reason than it's a somewhat expensive concept for a learning project. Four times any driver worth a dang is a significant investment versus that of a less ambitious project. If I understand correctly, your intended use is for this to pair with a Marshall-type amp; If you're absolutely wedded to the vintage look; your original idea of a horizontal 212 might be a better place to start. It could be styled as a old Fender or Marshall easily enough, just don't use those old original Fender dimensions as the starting point.

If you're looking at the Basslite drivers, you want to use the 'regular' version vs. the 'LF' versions in your design considerations. The LF versions are not suitable for cabs that don't have additional MF or HF components. IMO anyway. Both the Parts Express and Eminence Web sites have design recommendation documents that will give you some valid internal volumes which can then be manipulated to suit the form factor you're looking for. Just for the record, bass reflex enclosures are slightly more difficult to design than sealed ones, but can yield a smaller overall cab design than a sealed one with similar LF performance. Or, viewed another way, you can get more LF from a bass reflex design than from a similarly sized sealed box. Again, the design recommendations from the manufacturers are very informative, but you need to educate yourself to the point where you can understand what they say.

I would also encourage you to look around on the Web at some different box calculators -- I'm suspicious of one that doesn't make an allowance for the baffle set-back. It might be enlightening for you to calculate the volume of one simple, rectangular enclosure with pencil and paper, just so you know what the calculator is doing for you. Use cubic inches (or better yet, liters) rather than fractions of a cubic foot, and start by calculating the interior linear dimensions.