well, if you hang out here, you'll get earfuls of information from everyone here... Lots of information to be had, though it may take a while to start sinking in.
As far as I know, there aren't really any newb sites for DIY speakers; if you want to learn, your best bet is to get a book. The one I seem to hear about the most is Loudspeaker Design Cookbook, but I don't know anything else about it, as I have never read it or looked it up.
Also, start building simple projects--start with full-range driver projects, or 2-way, or open-baffle, which are easier (IMO) to design and build than more complex designs like 4-way active 18th-order bandpass sub, and 5 of 'em for home theatre... Don't get too ambitious from the get-go. Patience, grasshopper!
Good luck to you, I hope you find all the information you need.
As far as I know, there aren't really any newb sites for DIY speakers; if you want to learn, your best bet is to get a book. The one I seem to hear about the most is Loudspeaker Design Cookbook, but I don't know anything else about it, as I have never read it or looked it up.
Also, start building simple projects--start with full-range driver projects, or 2-way, or open-baffle, which are easier (IMO) to design and build than more complex designs like 4-way active 18th-order bandpass sub, and 5 of 'em for home theatre... Don't get too ambitious from the get-go. Patience, grasshopper!
Good luck to you, I hope you find all the information you need.
Start with The Loudspeaker Design Cookbook as has been suggested.getafix said:
You can try the Madisound forum but I think that this forum (diyAudio.com) is by far the best.
Ask the question and you'll probably get the answer.
Good luck.
Not to be contrary, especially to such knowledgeable fellows but, if the first book I read on loudspeaker design was the Cookbook I may have given up right there. It's very involved and possibly overwhelming to someone just getting started. I usually recommend The Great Sound Stereo Speaker Manual by David Weems to get started. Once you're comfortable with that the Cookbook will be much more enjoyable and understandable.
I think that's a fair point. We forget how long we've been playing this game. I haven't read the David Weems book that you mentioned but I've dug out an older book by the same author and it does seem a little more basic. My version of the Cookbook is from the 80s. I suppose it has moved on a bit since then.Timn8ter said:
Steve
Re: Re: DIY sites
I can't recommend starting with that book. It's tough going for a complete newbie. I speak from very recent experience. There are far too many terms that he uses without defining, or without defining adequately. It gets very, very frustrating.
For example, on the first page of chapter one, he gives,
Q -- ratio of reactance to resistance (series circuit) or resistance to reactance (parallel circuit)
Qts -- total Q of driver (woofer) at fs, considering all driver resistances
I couldn't figure out what that meant the first time I read it, and if the awful truth be known, I *STILL* don't know what it means. I've now seen enough graphs of low-Q this and high-Q that to have an intuition for what the effect of Q is, but that's about it.
I've read the book three times now, and I still can't understand most of it. Furthermore, the name is deceptive. It's not a cookbook at all. It's more like a sophmore textbook for wannabe cooks. We freshmen can't make heads or tails of it.
7V said:
I can't recommend starting with that book. It's tough going for a complete newbie. I speak from very recent experience. There are far too many terms that he uses without defining, or without defining adequately. It gets very, very frustrating.
For example, on the first page of chapter one, he gives,
Q -- ratio of reactance to resistance (series circuit) or resistance to reactance (parallel circuit)
Qts -- total Q of driver (woofer) at fs, considering all driver resistances
I couldn't figure out what that meant the first time I read it, and if the awful truth be known, I *STILL* don't know what it means. I've now seen enough graphs of low-Q this and high-Q that to have an intuition for what the effect of Q is, but that's about it.
I've read the book three times now, and I still can't understand most of it. Furthermore, the name is deceptive. It's not a cookbook at all. It's more like a sophmore textbook for wannabe cooks. We freshmen can't make heads or tails of it.
Q.... *sigh*
I've read tons on Q, and all I know now is this: low Q is GOOD, lower Q is BETTER.
Having built 4 dipole cabinets, I have to say, if I'd had any idea the effect of Q on the final sound quality, I'dve spent the extra $50 per driver to get lower-Q woofers. For dipoles, this is a must. Forget what anyone says about using Q as a crude EQ--just turn up the "bass" knob on your reciever!
Getting into this esoteric and complicated subject is very hard for noobs, and I'm frankly amazed I got as far as I did without burning out, like I do on all my other major goals.
Good luck to everyone anyway, and I hope we can, over time, flatten the learning curve some...
I've read tons on Q, and all I know now is this: low Q is GOOD, lower Q is BETTER.
Having built 4 dipole cabinets, I have to say, if I'd had any idea the effect of Q on the final sound quality, I'dve spent the extra $50 per driver to get lower-Q woofers. For dipoles, this is a must. Forget what anyone says about using Q as a crude EQ--just turn up the "bass" knob on your reciever!
Getting into this esoteric and complicated subject is very hard for noobs, and I'm frankly amazed I got as far as I did without burning out, like I do on all my other major goals.
Good luck to everyone anyway, and I hope we can, over time, flatten the learning curve some...
Q is not that hard guys. first break it up into electrical and mech.
the mech part simulates a spring. high school spring physics would give you a good idea. remember those expriments eith small weights at the end of the spring? the srpin in this case is the spider, surround etc...
electrical Q is a matter of an electromagnetic ckt with a coil in ca mag gap. this is a little more diffcult to understand as once cannot "see" the operation. one has to visualise it. it is like equating a mech equation like F=ma to a electrical one like P=VI.
before i hijack the thread i think there are sites out there that deal with both springs and compliance and electromagnetiism that can offer detailed explanations.
the mech part simulates a spring. high school spring physics would give you a good idea. remember those expriments eith small weights at the end of the spring? the srpin in this case is the spider, surround etc...
electrical Q is a matter of an electromagnetic ckt with a coil in ca mag gap. this is a little more diffcult to understand as once cannot "see" the operation. one has to visualise it. it is like equating a mech equation like F=ma to a electrical one like P=VI.
before i hijack the thread i think there are sites out there that deal with both springs and compliance and electromagnetiism that can offer detailed explanations.
I think this is what they mean, navin and also what I meant when I said that we have forgotten how long we have been playing this game.navin said:
Do your paragraphs above explain Q to complete newbies?
The mech paragraph doesn't link Q with the spring. For instance, what happens if a spring has low Q or high Q?
The electrical paragraph is even more obscure to a beginner.
Also, many people were totally turned off high school physics at school. I suspect that many would-be speaker designers need to relearn the basics of high school physics.
I don't say this as a criticism and I don't say that I could do any better myself. Just that it's not easy describing these concepts so that beginners can understand them.
Can anyone else come up with a simpler explanation of Q or expand on navin's version?
7V said:
one day when i can afford to retire i will spend more time on this site right now i butt in and out between work. unfortunately high school physics turned me on. i was (still am) too ugly for the women anyway.
changing mech Q (in spring physics) would depnd on the spring qualities as well as the load (if any). and dont forget that a loudspeaker suspension is actually many srpings in series and parallel (if you can visualise the suspension to be one spring and the spider(s) to be another) spring qualities are dependant on the thickness of wire, number of turn, distance bet turns, dia of turn etc....
maybe these links can help
http://physics.nad.ru/Physics/English/spri_txt.htm
http://www.maximacar.com/enclosure_design.htm
http://www.physics.csulb.edu/151lab/exp9/theory.html
http://theory.uwinnipeg.ca/mod_tech/node33.html
i am sure there are better (can anyone find a copy of Fundamentals of Physics by Resnick / Halliday) we used that in school.
http://physics.nad.ru/Physics/English/spri_txt.htm
http://www.maximacar.com/enclosure_design.htm
http://www.physics.csulb.edu/151lab/exp9/theory.html
http://theory.uwinnipeg.ca/mod_tech/node33.html
i am sure there are better (can anyone find a copy of Fundamentals of Physics by Resnick / Halliday) we used that in school.
I thought Q was the funny old guy in the James Bond films.
Anyway, back to the speaker building sites ... If you're new to speaker building, it might be worth tackling a kit speaker first off. There are lots of them out there - pick something simple (not your ultimate speaker), learn from that and then launch into designing your own. Some of the kit sites have information on them which is of general use.
Regarding books, there is a little book called AN INTRODUCTION TO LOUDSPEAKERS by Vivian Capel, published in by Babini (www.babanibooks.com). It's very simple and straightforward - only includes one speaker design but good on general principles.
Colin
Anyway, back to the speaker building sites ... If you're new to speaker building, it might be worth tackling a kit speaker first off. There are lots of them out there - pick something simple (not your ultimate speaker), learn from that and then launch into designing your own. Some of the kit sites have information on them which is of general use.
Regarding books, there is a little book called AN INTRODUCTION TO LOUDSPEAKERS by Vivian Capel, published in by Babini (www.babanibooks.com). It's very simple and straightforward - only includes one speaker design but good on general principles.
Colin
Timn8ter said:
Good point. I only just bought the 6th ed Loud speaker design cookbook (haven't had a chance to read it yet).
I cut my teeth on:
"Designing, Building, and testing your own speaker system with projects" By David B Weems. Would recommend it for newbes as it's not too technical.
List of chapters:
1. How a speaker works
2. Kinds of speaker enclosures
3. Speaker box construction
4. Closed Box speaker systems
5. Ported Box speaker systems
6. Crossover networks
7. Fun with a computer program
8. How to choose and use your speakers
9. Testing your speakers
10. Projects
Appendices
A Usefull Formulas
B Wire data for Homemade coils
C computer programs
D mail order houses.
Regards,
Tony.
Ray Alden's "Advanced Speaker Designs (for the hobbyist and technician)" is another good beginner's book. Vance Dickason's Loudspeaker Design Cookbook should make more sense after reading Alden's book.
Of course, all theory and no play is no fun at all. Theory should make more sense if you play around with simulation software...
begin shameless plug {
Subwoofer Simulator -- bass enclosure simulation program
Crossover Simulator -- electrical filter (crossover) simulation program
} end shameless plug
.... to help make better experimental enclosures and crossovers. Almost everything you'd need to successfully design loudspeakers from the ground up can be found at the FRD Group site.
Steve Ekblad maintains one of, if not the biggest, audio links page.
HTH
Isaac
Of course, all theory and no play is no fun at all. Theory should make more sense if you play around with simulation software...
begin shameless plug {
Subwoofer Simulator -- bass enclosure simulation program
Crossover Simulator -- electrical filter (crossover) simulation program
} end shameless plug
.... to help make better experimental enclosures and crossovers. Almost everything you'd need to successfully design loudspeakers from the ground up can be found at the FRD Group site.
Steve Ekblad maintains one of, if not the biggest, audio links page.
HTH
Isaac
Re: Re: Re: DIY sites
Finally someone who has the guts to tell the truth about that book. I had exactly the same feelings about it. I have a science background and I can say that if I ever wrote something like that during my student days, my professor would throw it out of the window.
The guy probably knows a lot about speakerdesign, but he sure can't write a decent scientific work.
Not a good beginners book.
Dave Jones said:
Finally someone who has the guts to tell the truth about that book. I had exactly the same feelings about it. I have a science background and I can say that if I ever wrote something like that during my student days, my professor would throw it out of the window.
The guy probably knows a lot about speakerdesign, but he sure can't write a decent scientific work.
Not a good beginners book.
Hmm.
After seeing plots of impulse (step? correct me if I'm wrong) response for different Q woofers, I think a good analogy is a car suspension. A good mechanic friend of mine told me that checking a suspension is easy--stand on the bumper and bounce once. If the car goes down and up once, your suspension is good. If your car goes up and down a bunch of times, your suspension is shot.
Good suspensions have low Q, bad ones have high Q. High Q will give you a horrible ride, and floppy, slow bass. Low Q will get a smooth ride, and tightly defined bass.
After seeing plots of impulse (step? correct me if I'm wrong) response for different Q woofers, I think a good analogy is a car suspension. A good mechanic friend of mine told me that checking a suspension is easy--stand on the bumper and bounce once. If the car goes down and up once, your suspension is good. If your car goes up and down a bunch of times, your suspension is shot.
Good suspensions have low Q, bad ones have high Q. High Q will give you a horrible ride, and floppy, slow bass. Low Q will get a smooth ride, and tightly defined bass.
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