This note is for Brad.
I really don't know anything about the WR125 driver you mention. Nonetheless, I am in the mood to ramble a bit.
1. The WR125 frame appears well suited to a larger spider. I believe this is important and is a normally a good thing. It is always a good thing to have a larger spider when a longer throw is needed. The larger diameter spider will provide greater linearity through the length of the voice coil travel. The only downside to a larger spider is that it will also have a higher moving mass. This will reduce the sensitivity and Fs of the driver.
2. Discerning the sound character of the driver isn't possible for me without actually hearing it. There is an art to properly integrating the cone and surround. This is true for stiff cones and soft/flexible cones. If done correctly the surround will damp unwanted cone vibration, yet move with the cone when desired. Some of this can be measured with a frequency response. Some can be measured with a waterfall plot. Some of this can only be measured with a Kippel. Oh, and it can also be heard with the human ear. Not all paper cones sound equal. I really liked the early GR130 Paper Cone driver from GR Research made by Peerless.
3. X-Max is measured differently depending on manufacturer.
Some manufacturers measure the distance from the "top" of the voice coil to the top of the top-plate. This may also be called the air gap. For example, an 18mm overhung voice coil having a 4 mm thick top plate would convey a 6mm X-Max. IMO, this seems fair and reasonable. While the motor force is somewhat reduced at full X-Max (depending on motor configuration), there is still a good motor grip on the voice coil.
Other manufacturers measure the distance from the "top" of the voice coil to the bottom of the top-plate. For example, an 18mm overhung voice coil having a 4 mm thick top plate would convey a 10mm X-MAX. A thicker top plate will increase advertising impact, but decrease performance. IMO, this is unreasonable because at full X-Max there is no substantive grip on the voice coil. Nonetheless, I have seen this method used for advertising.
//
I have thought of using an accelerometer to analyze cabinets. The raw part is fairly inexpensive, but it remains in the category of things that "I really should get accomplished". It would indeed be very simple to attach to loudspeaker measuring gear. The accelerometer would simply replace the microphone.
I agree with your wife. You need to make some coin.
I do appreciate your sentiment
, but my our perspective on this issue has changed slightly. I am smart enough to know this hobby is a blessing. How many guys have a hobby that only costs $1k/yr (or less) to maintain? As such it's a blessing. And, my wife has mellowed too. She recalls that her Father had a small hobby farm that never did make any real money. The farm lost money many years. Crudely crunching the financial numbers on his corn planted in sandy fields resulted in @$ .50/hr IF none of the 40 year old equipment broke. My wife and I both believe that all things will happen in God's time.
I wish TC sounds would get with the program, you are losing ROI on the work you have done. I would have purchased a three way from you.
Me too, and I appreciate your vote of confidence. Certainly a good 3 way will sound better.
Herein I would like to ramble a bit.
In my formative years any decent speaker was a 3-way. This perspective was very deeply ingrained and seemed immutable.
Nowdays a good 2-way can sound... really darn good. Certainly many companies have sold a plethora of very respectable 2-way speakers. At the top of the heap, kharma sells a 2-way floorstanding speaker for $45k:
http://www.audiofederation.com/dealership/kharma/ . Sonus Faber sells a good 2-way. The ACI Jaguar is also exemplary.There are others to, but the hour is late and my mind is getting foggy. Anyhow, my point is that a 2-way can sound very good. I would much rather listen to a good 2-way (i.e. the 1801 or Jim Salks 2-way) than the vast majority (perhaps all) of the $3k (or less) 3-way speakers. IMO, 3 lesser quality drivers cannot equal the results obtained when using 2 very high quality drivers.
My desire to build a big 3-way speaker isn't driven by a holistic desire for better sound. My desire is driven by male testosterone, and American lust for something bigger & better. I have a similar lust for a fancy sports car or some Marchesini forged magnesium wheels for my Aprilia. The only way I can truly justify the construction of a larger speaker is through my mental exploration during the process and the resultant knowledge obtained. I really don't think it can be justified from a value perspective because it'll be very very expensive. Sure, it'll sound better than the 1801, but there are so many other things in hifi that can be obtained that are a better value when implemented in a stereo system.
On top of this you are honest about the science/engineering or lack of within the audio industry. There is way too much hype and pseudo science within the industry.
Lately I have started to believe quality control is the most neglected aspect of loudspeaker manufacture, and the aspect most customers assume competence. This is a sad dichotomy. Fortunately there is at least 1 guy in a good postion to convey the truth about this arena. Dennis Murphy is a professional postion of legal immunity with regard to such issues, and has conveyed very painful truth regarding many of the more commercial speakers he has tested. Probably the most painful was the Norh 9.0 from Mr. Barnes.
http://murphyblaster.com/content.php?f=marble.html I do NOT think this an is the only speaker with such problems. I actually think Mr. Barnes is well above average. I have heard many other stories of commercial measurements of "big company" X loudspeakers that were equally bad. However, as a loudspeaker manufacturer without substantial legal staffing I cannot an will not convey this openly. // Heck, a couple years ago I noticed that Monster Cable was suing a company that made kids video tapes having the word "Monster" in the title. I didn't follow this story completely, but it may have killed the kids video tape company.
okay... that's enough rambling.
Good night,
Dave
