Base-Reflex enclosure.

Re: Base-Reflex...

Hi Grey...
First tnx for the very quick response. Did not expect it. Any way it looks like this is going to be a little more difficult than I had anticipated. After choosing a spkr to use (spkrs) how does one go abouit using the chara. of it to develope proper spec.'s for an enclosure? The intent here is not to reinvent the wheel but certainly would be nice to get fair results for my effort.
Larry.
 
Larry,
You'll need what are known as the Thiele-Small parameters. (Named after the two guys who did the analysis back 25 years ago, or so.) Then hit the Links section. There are several places online where you can access programs that accept those numbers as input and generate cabinet volumes as output. The configuration you use to achieve that volume is up to you, but I'd caution against getting too far off of a normal box configuration--a cabinet 2" deep by 4' square will not behave the way you expect, due to rear loading of the driver.
If you build a reasonable approximation of a Thiele-Small enclosure for your driver, you will get good results (assuming that you started with a decent driver).
Sometimes, the driver manufacturer will give suggested enclosure volumes. Those are assumed to be Thiele-Small volumes.
Proceed patiently and carefully and you'll have a good speaker. Oh, and be sure to plan ahead--you're going to need either a passive crossover or an active one. More fiddle-factor, I'm afraid.
Good luck.

Grey
 
Larry,
Something else to consider as a possibility is a project speaker where someone has done all the hard parts, design wise. There are several designs on the web. The unfortunate thing is that your next impulse is to ask which one is the best...you are then rewarded with 25 replies, each touting the speaker *they* happened to choose to build. Rarely will you find someone who will stand up and say (or admit, I should say) that the speaker they built really is pretty mediocre after all. This is a variation on Beranek's Law, which states something to the effect that: If you have invested the time to design and build the cabinet, and bought the drivers, and fiddled the crossover, and so forth, then you're going to say it's the best speaker in the world.
Make the best choice you can, then live with it--shouldn't be too hard. To you it will be the best speaker in the world...

Grey
 

blmn

Member
2001-02-01 2:43 am
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Larry,

GRollins is right. I just add you must looking for some information on the Internet or in a good Thiele-Small book about the alignements of bass-reflex enclosures, to achieve the response characteristic that you prefer.

Regards
 
Ok Gentelmen...GREY & REGARDS.
I think that may be I have lead you astray as to excatly what I'm trying to do. Yes, build a "Base-Reflex" (2 enclosures) and I am going to put them in my wood shop. Now that should tell you guys somehing right there. I like music. The spkrs I have now (on a scale of 1-10) are in the area of about -3. Thought it time to up grade a bit. There are quiet times in the shop and though the units dont have to be greatest I would like to have something with nice fidelity and of course not cost me an arm/leg. By the way Grey, liked your analogy of my thing is better because it took 10 min. longer to make. Had to laugh at that. So true. And of course REGARDS is supporting you so I am in good company. True you would think there was a site that could show some detailed drawings, enclosures that have been found to work well BUT I sure as ____ cant find them. Beleive me I've tried. So I'll take Grey's suggestion, pick out a couple of drivers, contact the mfr. get some volume requirments and go from there.
Thanks again to both of you for the help. This is a good site for the quick response. Bye guys
Larry
 
There are not enough words in the English language to cover how much I hate Windows...merde!
Larry,
I had a reply all ready, but this machine had other ideas.
Okay...Take 2.
If your shop is anything like mine, it's frequently loud.
Time to do the 'Grey thing' and break this down into bite-sized pieces:
1) Are you going to want to play loudly enough to hear over the equipment? (*Please* say no...)
1a) How loud do you want it?
2) Do you even care if it's stereo? We're out of the realm of delicacy and finesse, here. If it's just background music
you're seeking, you can save a lot of money.
Depending on how you answer the questions, here are some suggestions:
-Consider picking up a pair of used speakers locally.
-Low cost PA drivers may do the trick, rather than hi-fi stuff which is going to be more expensive.
-What about--don't laugh--car stereo? I ran an old car stereo in my shop for years. Think about it--they're engineered for a harsh environment (temperature extremes, dirt, vibration, you name it). They're compact. They can play loudly (if you get a big enough one). If you think this is your ticket to ride (sorry, couldn't resist), I'll bow out and let blmn take over, as I believe this is more his area of expertise.

Grey
 
Hi Again~~
Friend of mine doe'nt like Window either. The other he dislikes is Mr. Gates. ha-ha
Your Questions::
1. No. Need to keep my attention on the board I'm cutting, and not my fingers.
1a) Cant have it too loud for the Mrs. up stairs gets cranky if its TOOOOO loud.
2). It must be stereo.
Did use an old car radio (monaura) and thought it time to upgrade. My dtr bought me a AM/FM receiver so there you go.
Keep in mind my wish is to have something with good bass response
with perhaps a fairly good coax spk, yes second hand. Good suggestion you had there.
Alright Grey, take care and we'll talk again another day.
Larry