17W75 D260

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Have a friend. Has Contour 1.3. Set a switch: 1.3 original / 17W75 only, without everything (0,6 solid core)!!! JLH (exacter CLH,-) for driving. Believe it or not, the friend says, he becomes matured,-)))
His switchposition: 17W75 without crossover or so (very clean amps are requirement).
The 1.3 are disasters. Dynaudio does build good chassis, but not speakers,-)

Dynaudio is a legendary manufacturer that certainly knows how to
voice a good sounding loudspeaker, on top of how to produce a
speaker unit. The simple logic says that it's harder to manufacture
a driver than to voice a finished loudspeaker. The proof is this


I am willing to simulate a loudspeaker based only on official data
but it won't be optimal.

How do you feel about making yourown measurements?

This thread will help you.

Is a community a proof,-?

I would try much more:
- how to build in a chassis,
- how to modify a chassis,
- how to build a stable and light case,
- how to build a less influencing case
- how to connect the components,
- wich diameters of wires,
- wich wires
there is so much, what a crossover, simulated or look-measured, not performs,-)

And: good sources, good amps, good "rooms" are necessary,-)
Try to do something along these lines.


  • Filter.jpg
    37 KB · Views: 377
Most designs I have seen for this bass driver are limited to a pretty small box.... 10L. But, on the spec sheet, it says "up to 15L".

I was hoping to go for a larger box for a little more low bass. Is this going to pose a problem? I have a box that's 10L already but I was going to experiment with something larger.
The bigger, the imprecise.
Cause the case becomes unstable, resonances (to inside and outside!) in all directions,
cause the encased air/volume builds a mass-spring, it does resonate,
cause the reflections (and more in-front-resonances) on/off the, probably, larger front -
tones, which are not recorded - much more diffusity...
... you would need a tweeter:)

Much better than a wooden case you build a stone-/concrete-case.
The opposite is the truth with 17W75. The greater cabinet volume gives
a lesser Qtc value, deeper bass output cutoff frequency and greater excursion
at Fc.

This driver has been known to bottom out at higher voltages,according to
some of the owners. I haven't got that particular type, only a more modern
version mw160 gt with a very stiff suspension.


  • FR 10 lit.gif
    FR 10 lit.gif
    17.7 KB · Views: 204
  • Excursion at 10W in 10 lit.gif
    Excursion at 10W in 10 lit.gif
    9.2 KB · Views: 201
  • FR 20 lit.gif
    FR 20 lit.gif
    17.6 KB · Views: 221
  • Excursion at 10W in 20 lit.gif
    Excursion at 10W in 20 lit.gif
    9.2 KB · Views: 201
I would put the driver in a 15-20 litre cabinet to get a deeper
bass out of it, bearing in mind that the price of it would be increased
excursion for the same wattage. The diagrams show it. The needed
wadding (light to heavy) will lower the Qtc somewhat and kill the
standing waves. That's allright.
FWIW, ~15 L net is a ~1.1 Qtc before stuffing and what was considered by the pioneers of audio to be the most correct for the driver's compliance [Vas], so it wouldn't surprise me that's why Dynaudio recommends it. for a T/S max flat 0.707 Qtc OTOH requires a ~764 L cab, so this seems the reasonable size range by modern dtandards.

Being somewhat math challenged, I've no clue why, but have found that using the mean of most things speaker cab design related yields an excellent compromise between size Vs performance, so personally would use ~107 L based on its published specs and assuming a low total output impedance.

An adequately sized box volume stuffed fully would lower the
Qtc to about this simulated value(10W), not counting the Rdc
of the low pass inductor. That is a sane approach. I know that
because I have already done the same thing with 24W75, whose
Qt rised to 1,2 ( manufacture 0,9) after being fitted with a new
foam surround.


  • 1.jpg
    40 KB · Views: 146
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.