Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

In this Discussion

Who's Online (4)

Please review the site Rules, Terms of Service, and Privacy Policy at your convenience. Rules, TOS, Privacy
Get familiar with the reaction system: Introducing the Reaction System

Orevox WP-4008 - Parts Express 4" Poly cone buyout

I believe these were around $13 for a pair when I grabbed them. They did not last long IIRC. 

Sample 1

Loudspeaker parameters:

Fs  = 63.03 Hz
Re  = 3.40 ohms[dc]
Le  = 125.01 uH
L2  = 216.15 uH
R2  = 6.48 ohms
Qt  = 0.42
Qes = 0.52
Qms = 2.06
Mms = 4.85 grams
Rms = 0.930019 kg/s
Cms = 0.001316 m/N
Vas = 4.44 liters
Sd= 49.02 cm^2
Bl  = 3.538650 Tm
ETA = 0.21 %
Lp(2.83V/1m) = 88.94 dB

Added Mass Method:
Added mass = 10.00 grams
Diameter= 7.90 cm

Sample 2

Loudspeaker parameters:

Fs  = 58.88 Hz
Re  = 3.53 ohms[dc]
Le  = 131.08 uH
L2  = 212.85 uH
R2  = 6.48 ohms
Qt  = 0.38
Qes = 0.47
Qms = 1.96
Mms = 5.45 grams
Rms = 1.027011 kg/s
Cms = 0.001340 m/N
Vas = 4.52 liters
Sd= 49.02 cm^2
Bl  = 3.894322 Tm
ETA = 0.19 %
Lp(2.83V/1m) = 88.42 dB

Added Mass Method:
Added mass = 10.00 grams
Diameter= 7.90 cm

Free air impedance:



Simulated in 6L tuned to 55Hz - pretty decent extension for a 4", and the two samples are pretty close in the models.



I took some FR measurements a while back.

So to get a rough idea of things, here is the baffle signature as calculated by Response Modeler:



Here is the farfield - I don't remember exactly the distance but I almost always measure at 1/2M:



Here is a nearfield:



Here is a distortion plot taken at 1M, 90db. It goes to hell at that volume level.



As can be seen from the variety of measurements, it exhibits a "cliff" in the response similar to many other cheap (and some not so cheap) drivers between 1 and 2K. While this can complicate crossover design, at least it does not have a corresponding breakup to deal with. 

One thing to observe, as well, is that this distortion measurement is taken on the wide open baffle - it is sure to be better in a properly design enclosure meaning it is probably pretty solid on the bottom end. 

I have a signature.
greywarden

Comments

  • Thanks for the measurements JR.  I picked up 2 pair at the tent sale for $12.80.

    Ron
Sign In or Register to comment.