Replacement for discontined Woofer found

[fin1bxn]

I have been trying to find a Audax 8" woofer for my Tangent RS2's
specs were
FS:25hz
QTS .24
VAS 3.35 cf
VC 25mm
magnet 26oz
Impeadence 8 ohm

I found a Pioneer B20FU20
FS: 29hz
QTS .20
VAS 3.9
VC
Magnet 20oz
Eff 93db/watt

This is the closest driver I found, I woudl replace both. Any ideas how bad a trade off this is and what might happen?
Thanks
Bob

[dcanuck]

Bob,

I would buy your Audax woofer if you decide to replace it with the Pioneer drivers.

David

[planet10]

Originally posted by fin1bxn
I found a Pioneer B20FU20

Is that the B20 with the whizzer?

The RS2 midbass is the same as the RS6 midbass, The RS6 woofer is different. The midbasses were off-the-shelf Audax diy units (the woofers tweaked a bit). I sold lotsa Tangents & the Audax midbasses so they are out there. Tweeter failure is most common, so woofers should be out there.

Another option would be to sell the good drivers on eBay (good T27s will fetch a fair bit) and retrofit the RS2 boxes. With the removable front baffle, it is pretty easy. For instance a Fostex FE167 BR would go.

dave

[sreten]

Hmmm.......

Taking a very large gamble they would suitable, not a good idea IMO.

As p10 says sourcing replacement drivers is your best bet, but finding
them is the main problem. I believe you need the large magnet version
of the two versions of the Audax bextrene 8" commonly used.

Or as also suggested by p10 retro fit something else into the cabinets.

The main issue with bextrene cone drivers is that they usually
have a large midrange peak corrected by the crossover, this
can be checked by sketching out the c/o topology.

Another option is to contact Wilmslow Audio in the UK and see if
they have a recommended replacement, they claim to be "experts"
on the subject, and certainly sold quite a few of the wanted drivers
when they were sold as kit drivers by Audax.

Personally I'd do a bit of research on really good older 2-ways and
find a tatty pair cheap and retro fit the drivers +c/o into the RS2's.

I'm assuming here the RS2's are the largish stand mounting reflex.
(may have got my models mixed up, but that model had T27's)

/sreten.

[planet10]

Originally posted by sreten
I'm assuming here the RS2's are the largish stand mounting reflex.
(may have got my models mixed up, but that model had T27's)

RS2s are the smaller sealed standmounter (~20 litre). The same drivers in a larger stand mount BR was the RS4. The RS6 was a stretched RS4 with a 0.5 woofer (same cone but with the 4 layer VC instead of 2 (IIRC) + some mass added to the dustcap.

dave

[planet10]

Originally posted by sreten
The main issue with bextrene cone drivers is that they usually
have a large midrange peak corrected by the crossover, this
can be checked by sketching out the c/o topology.

The XOs were made by Falcon or Badger AFAIK... i thot i had an RS4 or RS6 XO-map but all i can find is a picture of the TM3 XO (same box as RS2, but with KEF B200)

dave

[sreten]

Originally posted by planet10


RS2s are the smaller sealed standmounter (~20 litre). The same drivers in a larger stand mount BR was the RS4. The RS6 was a stretched RS4 with a 0.5 woofer (same cone but with the 4 layer VC instead of 2 (IIRC) + some mass added to the dustcap.

dave

Hmmm.....

It was common at the time, for Audax and Peerless to name 2, to
make 2 versions of esentailly the same driver with different magnet
sizes, the smaller magnet version going into commercial sealed boxes
and the larger magnet version generally going into larger vented boxes.

If I remember correctly the smaller versions had a J suffix, larger H.

/sreten.

[sreten]

Hi,

B200/T27

shows a typical crossover of the period, 2nd order / 3rd order
electrically asymmetrical. What is also typical is the LC circuit
that controls the typical bextrene mid range peak.

Ideally this would be adjusted for the particular driver .......

/sreten.

[planet10]

Originally posted by sreten
If I remember correctly the smaller versions had a J suffix, larger H.

It has been a long time since i could rattle of the exact Audax numbers.

They all had H in them IIRC... H2 = 2 layer VC, H4, 4 layers

dave