Does someone know this speaker?

[docjoe]

hi
audax is definitely out of buiseness
you can have some answers on :
http://www.audax.fr/forum/index.php3?idpage=1

http://www.e44.com/

this is a HM 170 Z 2 speaker
z stands for "aerogel"
2 is the number of voice coils

if you read 4 ohms , this is a made to order speaker, usualy they were 8 ohm.
you use the first voice coil for added bass ( or baffle diffraction compensation) through a 10 mH inductor.
then the second VC is filtred as usual with a series coil or coil/capacitor cell.
my advice is to use a simple 0,15 mH coil in series with the second VC and add a high pass filter to the tweeter.

[e-side]

Thanks for all the information.

the hm170z2 also really looks like this driver...
maybe even more than the hm170g8, because the 170g8 has a different dust cap.
But what kind of material is aerogel? the cone looks like paper

[Stixx]

me jumping back in again...
Aerogel is a mixture of different fibres formed to a cone that was devellopped by Audax and used exclusively. I still have a pair of HM 170Z lying somewhere waiting to be used...
From the pictures I'd say it is a paper cone......

Maybe you have to find somebody to have your TSP measured...

[docjoe]

Well from the looks of the backside of the cone, i would say it IS aerogel!
if your cone backside looks like a grey rough surface kind of felt, and when you touch it is feels stiff that's definitely aerogel.

I have suffisently dealt with such cones to know!

the dustcap is maybe Vision proprietary, usualy it came with a rubber cone or larger dustcaps.

if i have time tuesday, i'll take a few shots of paper cone and aerogel cone backsides, just to compare
then i'll probably find some audax technical sheets...

[docjoe]

Hi e-side:
here are two shots of the back side of a paper and aerogel cone: you can see the small lines on the black paper caused by pressing the pulp
the aerogel cone, seems thicker, it is grey and rough feeling to the touch

first the paper cone:

[docjoe]

now the aerogel cone

remark : both cones come from audax and are used undifferently in cast or stamped frames.

[e-side]

When i see this aerogel cone i think my driver has a paper cone, because the cone's back surface is smooth, and it doesn't look like the aerogel cone. But thanks a lot for the effort!

I also emailed e44, but they sent an auto-message telling me they don't accept emails at the moment, because of spam.

[docjoe]

well, I tried
but I cannot help much for paper cones...
hope you'll find by another means

[e-side]

Apparently i have to measure the TSP. At http://www.diysubwoofers.org/measure.htm they explain how to do. Could I use this method or should i use an other??

[Stixx]

To measure the tsp you'll need a suitable software and a decent soundcard on your PC.
When my memory doesn't fail on me there is good freeware available, like Justmls (??) or the german Hobbybox (full demo). They measure via a mls-signal, you can even measue frequency response and such. Hobbybox also lists suitable soundcards....