Break-up in woofers

[KSTR]

On the other hand, a proper acoustic low pass filter after the radiator but before radiation can reduce the total distortion..

Yeah, just like you do in the Synergy's. Placing lowpass chambers in front of drivers is something we hardly see in classical domestic and studio speakers, direct radiator type. The Genelec coaxials with hidden woofers are the only exception I'm aware of.

 

[Digital_Thor]

Thank you Indeed I understand that non-linear distortion is not something nice and absolutely not fixable with EQ.
What I still cant wrap my head around, is why so many start to use hard cones in even very expensive loudspeakers - and when I look at the datasheet - then a Paper version of the RS225(+8dB at 3kHz), has a larger breakup, also lower in frequency - than the RS225 Alu version(+6dB at 6,5kHz).
But as KSTR points out - both the RS125 that I cross at 2kHz and the RS225, would be way past 4 times higher in fequency before breakup occur.
Does breakup gain anything from EQ? I mean, could I simply notch the breakup before I apply the filter, to have even less off second and third harmonics?

 

[Digital_Thor]

Yeah, just like you do in the Synergy's. Placing lowpass chambers in front of drivers is something we hardly see in classical domestic and studio speakers, direct radiator type. The Genelec coaxials with hidden woofers are the only exception I'm aware of.

Is this kinda of what they try to do with the small cap on the Scan 9800 and SB ADC tweeter?

 

[KSTR]

Is this kinda of what they try to do with the small cap on the Scan 9800 and SB ADC tweeter?

No, that little plate in front of the tweeter center is more a diffusor but it might affect distortion as well.
A true acoustic lowpass via front chamber is different in that it encloses the full active aread of the driver in an air volume with only one small and defined outlet.
https://en.wikibooks.org/wiki/Acoustics/Filter_Design_and_Implementation#Low-pass_filter

 

[Jim Matthews]

I'm tripping about Tom Danley posting here.

Dude is a genius : he makes things that exceed the standards of the day and they actually work so well even college kids can't break them.

*wow*

 

[Digital_Thor]

"With the aluminum cone Dayton woofers, the 8" and 10" inch versions I have tested have an aluminum cone and a LARGE resonant peak which when used as a woofer alone, is still audible with music.

A driver engineer once told me the reason we mostly use paper based cones is, it is the lightest, strongest thing that has enough internal damping and is cheap enough.
Best Regards
Tom Danley
Danley Sound Labs

Thank you for your comment I know it's been a while, but when you refer to the 8 and 10 inch versions of the Dayton drivers.... at what frequency did you use them in the test? If the resonance of the RS225 starts at around 4kHz and I intend to cross at 400hz with LR4 filters.... then what?

 

[Digital_Thor]

So... been thinking about possibilities, while printing a waveguide for a SB26ADC and waiting for at set of MW13TX - and building boxes for a set of RS390HF
When I look at a driver like the SB WO24-8, what technically makes it better than SB23CAC/BAC or RS225? - which in the end should make me want to pay twice the price per unit.

I don't need low-end extension (below 50-60hz) - because I have four subwoofers in mulit-setup
I want closed boxes - easier to build, and mostly I find them sounding better
I don't play insanely loud, have lots of amplifier power, and run fully active with a DSP
Aiming to cross to my midrange at around 400-600hz to relieve it from woofer duty

Could it be that most woofer are actually fine in my case? Because the breakup is mostly so high up, that it's only an issue when using it for both midrange and woofer - like in a 2 way?

 

[Digital_Thor]

Found this one - needs translation though - but the message is pretty clear:
http://www.justdiyit.com/grand-comparatif-de-10-pouces-partie-1/3/

Seems like Dayton RS line, is just pretty hard to beat (price/performance), when used within it's limits

 

[Digital_Thor]

So... a follow-up. I finally made up my mind on woofers
They should be coming in the beginning of next week and be part of my newest project with a KEF coax.
Wavecor WF223BD02 - four of them, for a stereo set in an MCM like KEF R900.
I got a good deal, and they seem like a technical good driver, well-built, pretty smooth, can play deep and have a very detailed data-sheet.
http://www.wavecor.com/html/wf223bd01_02.html
Will it make a difference? I don't know. But I tried to challenge myself with all possible sides, from others, my own experience and raw data from all angles.

Let's see what happens....

 

[Digital_Thor]

Open up my new stuff. Nicely packed, all seems good. To the workshop and build a pair of new frames to accomandate the slightly smaller basket. Then I measure and see the difference.

Apples and speaker drivers.... thought the color scheme looked nice.... and they were there, and handy

 

[Ramon Cota]

Soo, are they better than sb23? Comparing distortion they are much cleaner 500-1000hz , but frequency response is less linear.

 

[Digital_Thor]

Soo, are they better than sb23? Comparing distortion they are much cleaner 500-1000hz , but frequency response is less linear.

I ended up with the SB Satori WO24P instead. Just a bit more expensive, but better motor and more surface area for its given size.
The Wavecor had an unfortunate small ticking sound, when playing low frequencies. And since I'm super nit-picky, the company I bought them from, was kind enough to swap for the Satori instead
The Wavecor seemed very good at everything, but I am very sensitive about stuff.... especially when I first got a hint of something that annoys me
It could have been a bad batch or something.... but I wanted to have something special and excellent this time. So that's why I swapped.

The Satori has more punch, because they seem to EQ better than the SB23. Somehow, they do not have an annoying "ring" to them in the mid-bass. They play deeper, with more fullness, without being slightly muddy, when I turn up the volume. They also have clearer representation of voices, when crossed at 400Hz to my coax.
And this is in the exact same enclosure as the SB23, same amp, same DSP, same room and same placement.
Just by listening to them.... after all these years of trying different drivers. I think I finally found woofers that do what I like and need

I will link to a further description of my current project. But here's a teaser