Loudspeaker design cookbook over my head

[patch]

Well, while you're at it, why bother learning to read? Pictures are good enough.

I want to include in the picture category both charts and overly chunked-down bullet lists. Set out without a clear description of the meaning.

One exception I like is Dr. Klippel - he is one of the best at explaining what his graphics and tables are saying. The explanation is right below or above the picture, not three pages away like the student has to deal with in lots of textbooks.

When having my hair cut recently, the technician was bubbling about her new experience "reading the classics." A walk-though at Barnes $ Noble proved to me that "picture books" are available as literature - and these are *not* sold in the juvenile section. All new to me. They are in the form of a well-bound comic book.

[ttan98]

Originally posted by SY

It may be hard line of me, but trying to do an original speaker design without math is like trying to compose music without knowing what a scale is. If you're not willing to get the basic mental tools, stick to kits. Original designs ARE a challenge, and a hard enough one that most home designs have egregious flaws. Why go into a fight unarmed?

there are people that I know that don't understand extensive Maths but able to design and build x-over and very good ones too. Mr Murphy, from Murphyblaster is one an ex-economist by profession. Also Danny from GR research has a business background, he seems to able to design x-overs.

They are electrical engineers who can design x-over but they don't sound good.

some people just have a nack for x-over design. It is easier if someone shows you the first few designs and after that lots of practice, talking and reading.

[Lynn Olson]

Hi there in Oregon - my old stomping grounds for thirty years! Still think about it every now and then ...

I was in your position back when I was working at Audionics. It was either learn how to design loudspeakers or look for another job - the manager assumed I knew all I needed to know based on an half-hour chat I had with Laurie Fincham at KEF and glad-handing the folks at the BBC. Well, there was a little more to designing loudspeakers than that ...

Before you get all tangled up in math, get a good physical grasp what sound is about. 1 kHz is about 14 inches long, 10 kHz is 1.4 inches long, and 100 Hz is about 11.5 feet long. This may seem obvious, but these dimensions tell you a lot about why enclosures and speaker drivers are the sizes they are. It also tells you why good speaker design is difficult - a frequency range of 1:1000 is an extremely wide range, even if you're making a radio antenna. Loudspeakers, unlike radio antennas, actually convert electricity to sound, an additional electromechanical conversion step that creates distortion and is abysmally low in efficiency (as low as 0.3% up to a high of 10%).

Most of the work in enclosures and crossovers is nothing more than filter design. When you select an enclosure to match XYZ driver, you are actually creating an electromechanical high-pass filter (typically between 20 and 80 Hz). All of those funky-looking parts in the crossover are there to separate the lows and highs for their respective drivers - and in a high-performance design, equalize them as well.

All of this fiddling with filter theory is to force the drivers to give you a reasonably flat response over a usable frequency range. That's what all the boring and arcane theory is about - making those doggone drivers behave.

[sreten]

http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/

http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm
http://www.humblehomemadehifi.com/
http://www.rjbaudio.com/projects.html
http://www.zaphaudio.com/

http://focus.ti.com/docs/toolsw/fold...t/tina-ti.html
http://www.linearteam.dk/default.aspx?download=winisd


Hi,

All the above are somewhat better than a cookbook. Understanding
the process rather than misunderstanding electrical theory is in my
book a better approach. Crossover design does not need advanced
mathematics if you know what you are doing and use tools to help
you. Theoretical derivation of electrical filter design is all well and
good if you want to design electrical filters but basically due to the
fact driver responses are acoustic not electrical most basic theory
will confuse you rather than educate you.

/sreten.

[bunzinthesun]

Richard, you said:

"finding delta for PRS and V t_ test volume equal tp V b, given cubic meters". I really don't know what that means in any language.

Yes, abbreviations and jargon can make an understandable subject completely impenetrable. It can be a real help to write down all of the words and symbols that puzzle you, then find, list and refer to the definitions while you read again.

If authors really want to be helpful they can go through a worked example. With a worked example, it is relatively easy to substitute our own parameters.

If you have a specific problem, like measuring Vas (Vas volume of air having the same compliance as the driver suspension [a way to numerically express the stiffness, or springy-ness of a speaker], perhaps some one here would be willing to help you through the steps. Or if you have an extra $100 check out WT3 woofer tester from PartsExpress.

Yes the Weems book is pretty useful to get a feel of the various speaker design concepts.

That said, speaker design is a very difficult venture, if you are looking for superior results. I like a challenge, understand math and electronics so I am not too intimidated. But design requires test equipment to be able to measure where you now are and figure what needs to be changed in order to get to where you want to go.
Without expensive test equipment it is going to be pretty difficult to achieve superior results.

As much as I am fascinated with speaker design, I would say that the smarter thing to do is to find a well respected existing design and copy it. Darn, it hurt me to write this!

You might want to check out:
Loudspeakers For Musicians
available from Parts Express

I don't have experience with this book, so I can not recommend, but there is some difference in design philosophy between musical speakers and home speakers. As in the difference between producer and re-producer. Efficiency, ability to play at high volumes without (undesired) distortion, burn-out and yes, deliberate tonal imbalance are of great importance.

[patch]

For me, technology and its math is a growing wilderness where it's easy to get lost and the night falls early. Always take a map and compass. Here are two math-friendly guides I refer to a lot.

"Contemporary Precalculus, a Graphing Approach" by Tom Hungerford.

"Electrical Principles and Technology for Engineering" by J.O. Bird.

To have basic audio science all in one place, I made sure to buy the big one from the man in Georgia. No-nonsense explanations and diagrams, even if they are set out alongside and around equations that look something excavated at Ur:

"Introduction to Electroacoustics & Audio Amplifier Design" by Mr. W. Marshall Leach Jr.

patch

[speakerman]

Hi, Richard -
Don't know if you're still interested in responses to your original post.

I highly recommend HARRIS TECH's speaker programs:
BassBox Pro
X-Over Pro
The manuals that come with these programs are terrific reading and will painlessly bring you up speed on speaker design. They are phenomenal tutorials on woofer box and passive crossover design.

Also very highly recommend Douglas Self's "The Design of Active Crossovers" should you want to understand active filter/crossover design.

Good Luck,
Angel

[Akrambash]

I too have the same problem understanding the math in "loudspeaker design cookbook"... even tough the book is very resourceful ,vance dickason's approach is bit weird. Weird in the sense that the book never follows bottom to up approach... To understand the book the reader should be well acquainted with all technical stuff. Then why a cookboook,which it is not, nor it is a total reference guide

[fatmarley]

Although the Loudspeaker-Design-Cookbook is full of interesting facts and also some interesting opinions. I thought there was far to many graphs and Vance seemed to waffle on a bit. i'm sure it could have been made much smaller without loosing anything important.

On a personal note, i've been getting much better results using my ears, rather than completely relying on facts and software.

[GloBug]

Originally Posted by planet10

The Basic & Advanced speaker building books (by Alden?) from Radio Shack might give you some of the background you need...but you will still have to be able to grasp the math -- or get into vintage full-range systems, then you can just say, if its a box, bigger is better (has to be solid too) and an open baffle is better but needs to be even bigger... then the math boils down to bigger

dave

I like this guy.