Exciting new line of fullrange drivers from Feastrex

[mluckow]

Incidentally, just to clarify, he just said that he has heard two drivers with the same T/S data sound very different. For all I know, he might have been talking about drivers made by some other company! Or maybe even two drivers made by two different companies.

So, I don't think we can assume too much from this.

Mike

[planet10]

Originally posted by GM
Even 'cookie cutter' high volume manufacturers that design them with minimal component tolerances can still be +/- 5%

From my experience those would be tight tolerances... the stuff i've been testing, +/- 10 acaerage across a number of parameters is normal, and +/- 15% or more on a specific parameter.

dave

[DaveCan]

Originally posted by cdwitmer


They are definitely matched in pairs . . . in fact Mr. Teramoto does not want to recone just one driver in the event reconing is needed for some reason . . . he'll want to work on that pair of drivers as a pair, even if there is nothing wrong with the one.

Comparison to Ferrari is scary . . . my next door neighbor works on expensive sports cars for a living and that manufacturer's cars seem to spend as much time in the shop as they spend stuck in heavy Tokyo traffic . . .

-- Chris

That makes perfect sense and is also very wise imo, just like you should never only repair the brakes on one wheel but rather do them in pairs!! I would imagine the same approach should also be taken in the boob job industry, otherwise one could assume very lop sided results

Dave

[cdwitmer]

I think the level of inter-driver consistency indicated by Nelson Pass for the D9nf drivers on a separate diyAudio thread is probably representative.

-- Chris

[BTW]

Here's the graph that Nelson Pass posted on the Feastrex Fun Thread....

[GM]

Originally posted by planet10


From my experience those would be tight tolerances... the stuff i've been testing, +/- 10 acaerage across a number of parameters is normal, and +/- 15% or more on a specific parameter.

dave

Well, admittedly my info dates from Altec, JBL back when vendors/employees usually took some pride in their work. I've seen the +/- 10% bandied about in a few threads, but nothing to validate it. WRT individual specs being far off, as long as the calc'd eff. is reasonably close to spec it doesn't matter from a box design POV.

GM

[jogi59]

Originally posted by cdwitmer


They are definitely matched in pairs . . . in fact Mr. Teramoto does not want to recone just one driver in the event reconing is needed for some reason . . . he'll want to work on that pair of drivers as a pair, even if there is nothing wrong with the one.

Comparison to Ferrari is scary . . . my next door neighbor works on expensive sports cars for a living and that manufacturer's cars seem to spend as much time in the shop as they spend stuck in heavy Tokyo traffic . . .

-- Chris

May i ask, how a manufacturer, that cannot measure T/S parameters or frequency response properly, can match speakers?

[soongsc]

Originally posted by BTW
Here's the graph that Nelson Pass posted on the Feastrex Fun Thread....

Hmm, there seems to be some similarity in response of these and EnABLed drivers. Although I have not listened to any of these. But the multiple SPL peaks seem somehow related with people hearing more detail.

[cdwitmer]

Originally posted by jogi59

May i ask, how a manufacturer, that cannot measure T/S parameters or frequency response properly, can match speakers?

1. Always build speakers in pairs.
2. Pay careful attention to consistency of all components.
3. Follow exact rituals for all aspects of assembly.
4. Take in-house electronic measurements
5. Extended listening to and confirmation of operation of drivers, including repetition of step 4 ("extended" is relative; days as opposed to a few seconds for most mass-produced drivers)

Remember, the voice coil former and cone assemblies, including surrounds, are all made by one person, who is also in charge of assembling all the drivers from beginning to end.

The consistency of matching does not seem to be inferior to what people get through mass production techniques.

There is more than one way to skin a cat, as they say . . .

-- Chris

[Russell Dawkins]

I guess one non-tech way to match drivers would be to mount them nearly face to face and in reverse polarity in large closed boxes and go for maximum cancellation.