No I more or less don't like the abuse of the term DBT. I went in and tweaked my language a bit for clarity. I encourage all that took issue with my article to please pain thru re-reading it and tell me if it reads better now.
I never said I was OK or content with Bose. I respect/admire their marketing and business model however. They are brilliant.
Here is what Bose doesn't do that some high end loudspeaker companies do:
- they DON'T publish measurements
- they DON'T publish specs
- they DON'T publish papers pretending to be DBT's
- they don't declare their speakers are "similarly good" to the very best and elaborate designs
- they DON'T target audiophiles
Bose mostly compares their product to what appears to be BIG white Van type rack systems. In most cases, their stuff will sound better than the alternatives they show in their ads and their stuff is a lot more compact and easier to use.
This is a good thread Gene, and I agree with your sentiments. It has taken a while to get through this thread.
I have a number of observations about speaker evaluation, and some are understandably controversial.
First DBT of speakers is nothing like DBT in medicine.
In the years of rapid pharmaceutical progress powering a study was easy. For instance it did not require many subjects to get a statistically significant result for treating pneumococcal pneumonia.
However as effective treatments for many problems progressed, it became important to find benefits of new treatments over old. In order to find small benefits of A over B enormous numbers of patients have to be often involving different centers world wide.
Now to make the data meaningful you have to minimize the variables among the enrolled patients. Otherwise you have to many confounding variables.
Now the end points are definite, such as death, strokes, bleeding episodes, days in ICU, all kinds of definite endpoints.
However, so many studies run on the rocks because of necessary inclusion and exclusion criteria. So endless arguments rage of selection bias and also about drop outs. There are frequent arguments over statistical methods. Don't forget we are dealing with definite identifiable end points as a rule, and not subjective issues like the sound of a speaker.
Now with speakers there are usually large easily identifiable differences between speakers, unlike other parts of the audio chain. So this helps.
However, I think testing speakers with other than highly trained listeners with well developed acoustic memories means nothing at all: - zero.
In my opinion only natural instruments in a known acoustic space can be used for loudspeaker evaluation.
In other words, the panel need to have heard musicians in a space in which they were recorded with the same music in a proximate time period. I firmly believe anything else is useless.
Pop and electronic instruments are hopeless for speaker evaluation.
That is why I use recordings made in a venue I'm familiar with for critical evaluation. If there is a CD available were I have heard a concert I buy it.
When I was at
Mahtomedi, MN for the concert celebrating 30 years of Pipe Dream broadcasts I bought a well recorded CD on the Pro Organo label.
The main reason that I made so many recordings over the years, was to evaluate speakers. To go from auditorium to the control room and hear it over my monitor speakers, really developed in me an enormously heightened awareness for the evils of speakers, and a steady improvement in results.
Measurements get you some of the way, but all the good designers I have known voice to a very large extent by ear. The good ones make changes to the design over long intervals after first getting the speaker reasonably balanced.
You are right that power handling is a huge confounding variable not addressed in almost all measurement programs, but it is among the most important factors in the design of a speaker, especially for classical music.
Recently I took measurements while listening to a very impressive BD release of the Mahler symphony No 5. There were prolonged quiet passages were the SPl was below the low range of 50 db. There was a lot between 65 and 85 db, with loud fortissimo peaks going to 102 db at least at the listening position. Now that presents a huge problem to the speaker, and drivers need to be underslung with good heat transfer from the VC among other attributes.
Now we get to an area others have touched on. That is the pretty much impossible task, in the US in particular, of being able to audition a wide variety of speakers. This is especially true at the upper end of the market.
This leads me to believe that the surest way to good sound in the home is to learn to design and build your own speakers. I'm unusual, in that I have never owned a set of commercial speakers. I have always listened to speakers I designed and built. So is there a selection for a particular
sound field? Yes, there must be. Friends and acquaintances have said my speakers have a definite stamp to them, which is usually described as full bodied with a very tight bass. Musicians in particular note the correct space around instruments. I think they mean by that, that the sound does not seem to emanate form the speakers, and the cues from the original acoustic space are preserved. They seem to like them. In Grand Forks we had a listening group and we all had very decent speakers. We would rotate venues, but overtime it seemed to drift more and more often to my place. I think that it all comes down to voicing to the space among other things. I believe speakers like organs have to be voiced to their space.
When I was recording, by monitors had switches on the back to subtley voice them to my most frequent monitoring venues, such as the Green Room at the Chester Fritz auditorium Grand Forks.
The above is yet another inducement to build ones own speakers. The down side is years of progress, but it is a fascinating journey, to Peter Walkers "Closest Approach to the Original Sound." That really has to be the goal of acoustic engineering.
