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Get familiar with the reaction system: Introducing the Reaction System
I have only been waiting almost a year
in DIY
To finally get my hands on a copy!
Comments
The things it shares with the LDC it also goes far beneath the formulas, and also talks history of loudspeakers, drivers, advantages and disadvantages of different designs and alignments, and on and on. Psycoacoustics is also discussed throughout.
I have come to find thecombine of the LDC, Toole's Loudspeaker book, Newell's loudspeaker book, D'Appolito's testing book, and hopefully now this which Collums is quoted by Toole, and made a contribution to Newells book will round it all out.
For me, there is so much available on the web by "well respected" sources. None of it sorts through opnion- bedazzled -by -"fact" like the books have which cite the real, scientific work that has been done in the past 80 years, put together by the real pros who have actually been a real part of moving the needle.
Absent reading the entire book, I cannot comment except to say it is all too easy for anyone in a hobby, of any kind, to get caught up in an apostle/disciple relationship. It is why it is very important to seek information from as many sources as possible and combine it with copious amounts of empirical data - read books and set up your own experiments etc.
I often draw a parallel between my martial arts career and other hobbies - in this case, there are thousands of people who have decided to adopt design philosophies espoused by one person (not any one in particular, keep in mind). Similarly, I saw many karate students drift off after an instructor moves or dies or retires or quits.
At this point in time, not sure what is left to discover on speaker design, nor am I sure I am interested in digging deeper into the underlying mathematics. To pull another correlation to martial arts - the best fighters don't need a PhD in biomechanics, they just have to be better at applying technique than the next guy.
That all being said, I would probably be curious to see what this book includes. I am always interested in different views and alternative means of analyzing data.
Let us know, Mike.
Also, what the one year wait - is this book out of print or out of stock?
During the 1st chapter he discusses that there have been speakers that have historically had a "house" soind, or gained popularity for not having a mainstream sound, but they all ultimately fall back into thw fray and proper execustion of all design variables comes back to rule.
He also mentioned that one downfall of many speakers is an improper handling of the acoustic power from lower midrange to tweeter crossover, and the aggragate of changes in frequency reaponse as a spectrum, like boosting the tweeter as little as 1dB, will appear to make the midrange more desirable, but long term leads to fatigue or noticable coloration to the sound to spite it sounding very attrative in a short-term test. So he states that the mjdrange is the most critical aspect of the sound to get BOTH technically and subjectivly right and the rest of thw loudspeaker will fall into place and be easier to execute.
My favorite quote so far:
The art of the loudspeaker deaigner is to use science to help increase the meaning of reproduced sound.
Interesting stuff, and in leiu of typng out the first 30 pages, I am leaving out a lot of detail...
The best is taking it and applying it, like you have said, added to other good info on the tool kit insted of simply subscribing to one single way.
It is not out of print, just hard to get. I use a lot of crayons and color in my books so I can look at them later, so I rather get new, but many are available used.
Basically here is my collection. None are useless and all are worth the read even if info overlaps.
https://www.amazon.com/gp/aw/d/0240520092/ref=mp_s_a_1_6?ie=UTF8&qid=1489611271&sr=8-6&pi=AC_SX236_SY340_FMwebp_QL65&keywords=loudspeaker+books&dpPl=1&dpID=51l2IVWvyaL&ref=plSrch
https://www.amazon.com/gp/aw/d/1882580478/ref=mp_s_a_1_1?ie=UTF8&qid=1489611271&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=loudspeaker+books&dpPl=1&dpID=51daWsDwhkL&ref=plSrch&dpPl=1&dpID=51daWsDwhkL&ref=plSrch
https://www.amazon.com/Testing-Loudspeakers-Joseph-DAppolito/dp/1882580176
https://www.amazon.com/gp/aw/d/1882580451/ref=mp_s_a_1_3?ie=UTF8&qid=1489611472&sr=8-3&pi=AC_SX236_SY340_FMwebp_QL65&keywords=loudspeakers+201
https://www.amazon.com/gp/aw/d/0240520149/ref=mp_s_a_1_1?ie=UTF8&qid=1489611522&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=loudspeakers+for+music+recording+and+reproduction
https://www.amazon.com/gp/aw/d/0470094303/ref=sxts1?ie=UTF8&qid=1489611582&sr=1&pi=AC_SX236_SY340_FMwebp_QL65
The key is taking it all and using it to understand how it works for you. The whole "doing" part.
One big question I am beginning to for a nebulous answer to is why the top 10 speakers I have heard are all commercial deaigns, and not one DIY design, even from some VERY popular designers and smart engineer-types sit on that list.
All the while I tinker and play with designs of my own to try and reconcile it all.
I just got the 6th. I do not have the 5th.
It is still a hoot, and the stratigy makes it a blast to have a few beers over and battle it out.
In chapter 3 he discusses diaphram types starting with domes. Since there is a time difference in raidiated frequency from the rim to the apex of the dome, there is a phase element called phase loss.
Looks like comb filtering and from reference level, can effect the power response of up to an octave below the forst phase mode. This has zero to do with break-up.
Phase loss does not always show up in the frequency domain, either, at least the low harmonics. Typically the dome hight of a 25mm dome is 7.5mm, putting the first phase mode at 23K, an octive below is audible if not properly delt with by the transducer designer. While axial measured response may be good, this can cause peaks and dips in the reverberant field in a room. I am gues(my note here) tjis accounts for some of the flavor tweet to tweet.
A 19mm dome does not have its first phase loss element assuming a typical dome height of 3.75mm until 46K, pushing any subharmonic effects to above 20K.
Interesting to note, too, is metal domes of 25mm diameter typically have a 5mm height which means due to phase loss alone, all else being equal to soft domes, they will have an inherent difference in timbre.
Thought this was cool. We focus so much on frequency response, axial response, and distortion there is a lot more at play to think about. Though this is out of our control, I think it can help us undestand how to better select drivers when thinking about a design.
Bill
Even the LDC does not give them a heck of a lot. They are more specitaly/niche, and most times similer performance can be had with less complex alignments. At least thats my guess why the love is limited.
Though notably, one of the best bass sections I have heard is from the Troles Elam which uses a 9"scan in a TL.
".....and in this case impared the overall fidelity. This design has enjoyed critical acceptane and it goes to show you that careful subjective assessment is a vital part of the design process amd may throw up inexpected contradicrions. When in doubt believe your ears first and look at explanations second."
This from the guy who WROTE the book on high performace loudspeakers. Sheesh.