Suggested reading on passive filter design?

[Porksoda]

Hey All,

I am looking for some reading material on filter design as it applies to loudspeakers. I have a fairly strong background in electronics and a VERY strong background in mathematics. I have a basic knowledge of analog filters, but anything beyond a simple RC or RL filter is a mystery to me. I know how to analyze a filter using simple paralell/series addition of real and imaginary numbers given an existing design, but I would like to learn the theory and math behind the design and development of more advanced filters as this is one area where Art of Electronics falls rather short.

Thanks!

'soda

[alan-1-b]

There is an enormous amount of stuff out there . If you have access to a technical Library , the look in the Journal of the Audio Engineering Society - {J.A.E.S.} - Peter Garde's paper from Vol.28 , No.9 , September 1980 , "All-pass Crossover Systems" gives a good sumary of the developments earlier and his ideas for new {then} . The References at end of his paper list some of the prior developers . ____ Look also at Siegfried Linkwitz's papers - at least one is in J.A.E.S. somewhere , and two were in "Wireless World" {now "Electronics World"} sometime in the 1980's - I have forgotten exactly when . Google search and find Linkwitz's web-site - plenty of links to things there-in . Look for what is named a Linkwitz-Riley crossover - in both 2nd Order and $th Order . ____ There is a lot more out there , but look at those and then post your comments here-under so I can know more precisely what you want , and I'll try to refine and condense down to a few References . ___ Happy hunting , Alan .

[Porksoda]

To be a tad more specific, I am trying to break into the world of home loudspeaker system design. I have been very active in the headphone audiophile DIY scene for a few years, and have gotten pretty good at that scale of electronics design. Sadly, it just doesn't drain my pocketbook to my satisfaction so I decided to really put myself into the poorhouse I would have to step up to full speaker systems

Basically I am trying to fill in the gaps between these two worlds, most of which in my opinion is in loudspeaker design (never mind greater than 2.1 channel setups for now). Things like passive crossover filters, enclosure design, driver selection, interference between drivers due to output signal phase, lobing, etc. are areas that I have a basic concept of, but not detailed enough knowledge to design anything. Moreover, because of my technical background, if there is a complex or difficult design out there that is worth the effort, I enjoy the challenge of trying to realize it.

I will start looking into those journals, and not to be an ingrate or anything but I was hoping there was a nice, thick book out there somewhere (like Art of Electronics) that covers the subject of speaker design in suitable detail in one huge volume.

[lufbramatt]

The first three references from my recently finished dissertation:

1. Colloms M, 1997. “High Performance Loudspeakers”, 5th Edition, Chichester UK: John Wiley & Sons Press.

2. Borwick J, 2001. “Loudspeaker and Headphone Handbook”, 3rd Edition, Oxford UK: Focal Press.

3. Dickason V, 2004. “The loudspeaker Design Cookbook”, 6th Edition, Peterborough USA: Audio Amateur Press.

are all quite informative and have chapters on passive crossover design, the first two are probably the best though with all the relevant maths in and sections about how to tune components to get the desired results. (and the first one is the thickest at about 2 inches )

[kwantam]

Much more theoretical, but an excellent read:

Guillemin, E.A. Synthesis of Passive Networks. New York: John Wiley and Sons, Inc. 1957.

-kwantam

[Ron E]

There are no big thick books that cover speaker design in one shot.

Loudspeaker Design Cookbook (LDC) by Vance Dickason is an entry level book with a primer on everything with non intimidating math. The cookbook formulas in the LDC will give you the coefficients for the different types of crossover transfer functions if you solve the circuits and substitute in the values from the formulas. This is the only thing I find it useful for, now.

Testing Loudspeakers by Joseph D'Appolito is a "look over my shoulder as I test and design" type of book with a fair amount of measurement theory and general discussion on crossover design.

Acoustics by L.L. Beranek is a timeless classic on general acoustics with applications - very theoretical, very mathematical, but a bit old school (1954) in methods compared to Thiele and Small articles in JAES (ca. 1971-1973)

Theory and Design of Loudspeaker Enclosures by J.E. Benson is an irreplaceable text on enclosure design. Almost entirely math, not for the faint of heart. Covers a single model that works for Sealed, Vented, PR - and 4th order bandpass if you learn a simple trick . The Benson book has a huge bibliography of firsthand sources (prior to ca. 1972).

Any college level electronics text that shows how to solve circuits with impedance using laplace transform methods (Zl=s*L, Zc=1/(s*C) will be required at a minimum to understand the last two books.

[ocool_15]

Speaker building 201-Ray Alden

Of the books I read he goes into the most detail on passive 3 ways.