Jump to content

Klipsch speaker Impedance curves


NOSValves
 Share

Recommended Posts

You do not need much.

A couple of 10 Ohm power resistor (you can wire in series or parallel to get different values). They have these for a dollar at Radio Shack

Volt meter (does not need to be fancy)

Tone generator (PC can do this and use any old receiver that is available).

 

This is just one way. use Google to get specifics

Link to comment
Share on other sites

  • 2 months later...

back in the day before I had WT, I sometimes used a non-RMS meter.  A 10 ohm resistor would be switched in as a load at every spot of interest, then the generator's output set to read "10" on the meter. When the 10 ohm load was switched back to the speaker under test, a fairly accurate reading could be taken.   The series resistor was 1K.  Time consuming but ballpark.

Link to comment
Share on other sites

  • 6 months later...
  • 2 months later...

Google "Impedometer" by Dick Pierce (of Usenet fame).  It will gives basics to measure the magnitude only of the complex impedance.  For complex impedance (R +jX) you  need the phase angle and the piece part setups don't do it unless you get a phase meter or like struggling with X-Y plotting on an oscilloscope.  Dayton Audio makes a thing called the DATS for $100 that you might considered.  I don't have one but if it outputs the results of a sweep in a spreadsheet your good.  If not then don't bother.

 

Link below shows how to use Excel spreadsheet to acquire complex impedance from test signal frequency, impedance magnitude and phase angle.

http://www.northreadingeng.com/Impedance/impedance.htm

  • Like 1
Link to comment
Share on other sites

  • 1 month later...
  • 4 months later...
  • 2 months later...
  • 3 months later...

I have a noob question that is unrelated, looking up the specs of my Cornwall Is I see their impedance is 4-ohms but I read it online where it says they are also 8-ohms compatible.

 

Does this mean I can run them with my amp setting at 8-ohms?

 

I also have a set of KEF 105.2 which is 8-ohms, can they be run with an amp that is set at 4-ohms?

 

Thanks,

 

Jimmy

Link to comment
Share on other sites

  • 1 month later...
  • 1 month later...

Well I did this sort of just for my own interest but others might find it interesting as well. Attached picture shows simulated R28F based solely on crossover parts (in black) overlaid with actual speaker impedance measured the other day (in yellow). Crossover parts list taken from here. VirtuixCAD2 used to create the overlay and sim the crossover, using 2 generic, flat 8 ohm drivers on LF and 1 generic, flat 8 ohm driver for HF.

Sim_Impedance vs Real R28F.png

Link to comment
Share on other sites

  • 2 months later...
  • 3 weeks later...

KG 5.5 all measured with DATS V2  in the free air (outside of enclosure) without crossover.

 

Workbench Notes for KG 5.5 woofer:

 

f(s) = 32.97 Hz

Q(ts) = 0.4774

Q(es) = 0.521

Q(ms) = 5.71

V(as) = 125.1 liters  (4.417 cubic feet)

R(e) = 6.336 Ohms

Piston Diam. = 215 mm (8.465 in.)

SPL = 91.24 dB SPL 1W/1m 

SPL = 92.25 dB SPL 2.83 Vrms

C(ms) = 0.676 mm/N
L(e) = 0.68 mH at 10kHz

BL = 9.321 n(0) = 0.8205 %

M(ms) = 34.49 grams
 

 

 

KG Lower Woofer free air.pdf KG Woofer data free air inc Vas.pdf KG Upper woofer free air.zma KG Lower woofer free air.zma KG Upper Woofer free air.pdf

Link to comment
Share on other sites

  • 8 months later...
  • 3 months later...
How this thread is very technical.....sorry too much for me. 
So for my 1990 Khorns what impedance should i choose ? 4 or 8 ohms ? on my Almarro 318 B ?
Thank you for your help 

I would choose the one that sounds the best.

I get tinny sound on the 8 ohm tap on my amp with Khorns. Tha 4 ohm tap sounds great. YMMV
Link to comment
Share on other sites

  • 2 months later...

Took an hour and measured my CF2's, Serial #'s 2335970xx

Low Frequencies:  Blue line is the later-series port (shorter), red line is with a construction paper tube to extend that port to first-series length, ~5" if I remember.
Pretty typical for a ported cabinet.  Looks like the shorter port tunes at around 38Hz, longer port is around 32Hz.  Impedance peaks shuffle around a bit, but the lower peak is always lower than the upper peak indicating they're maybe both tuned a bit 'low' for the drivers in the box.

 

High Frequencies: Definitely seeing the effect of the Constant-Directivity crossover attenuating lower horn frequencies to give the horn a 'rising slope'.  Surprised to see the impedance settle out to around 4 ohms at the top, considering the 8-ohm driver used, and the 8-ohm nominal impedance of the cabinet.
 

 

CF2 Impedance Low.PNG

CF2 Impedance Hi.PNG

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...