Wallin II / SW impedance calib problem

ultrachrome · 19th September 2005, 05:31 AM

I'm having a heck of time peforming the impedance calibration with my jig.

My impedance curves for my drivers never dip below 12 ohms for what should be 7-8 ohm drivers.

My jig measured out correctly after I built it but I notice that when I have J2 and J3 connected to my sound card (M-Audio Transit USB) and set the jig to 16 or 4 ohm calibration mode that BP3-BP4 measure 31 and 8 ohm, respectively. Is that normal?

My other problem is that the calibration process says that I appear to have an open connection.

I've tried connecting it to the laptop's internal sound card and have tried different cables but I still keep getting the same error message.

Any ideas?

noodle_snacks · 19th September 2005, 08:26 AM

Have you gone through the process of setting the levels using loop record mode and a sine wave? I found the peaks of the waveform clipping were giving me some trouble in impedance measurements.

Vikash · 19th September 2005, 10:15 AM

Quote:

Originally posted by ultrachrome
My jig measured out correctly after I built it but I notice that when I have J2 and J3 connected to my sound card (M-Audio Transit USB) and set the jig to 16 or 4 ohm calibration mode that BP3-BP4 measure 31 and 8 ohm, respectively. Is that normal?

That's not normal. I suggest going through the jig electrical checkout first.

ultrachrome · 19th September 2005, 03:56 PM

Looks like it's a problem with my laptop. In the IMPCAL16 mode, the BP3-BP4 resistance measures 32R when plugged into the Transit and 64 when plugged into the laptop's line in.

Did the Wallin checkout a second time and found no problem.

Took the jig downstairs to my desktop line in and IMPCAL16 meausures 16R just like it's supposed to.

Crap. Now I need to drag my desktop upstairs. Girlfriend is not going to like that.

ultrachrome · 19th September 2005, 03:59 PM

Wow, that auto-censor is touchy. If you make that word plural, it's a dice game.

wintermute · 20th September 2005, 11:04 AM

Did you try measuring again after doing the first calibration? sometimes if the calibration is out it will take a few goes to get a proper reading.

The other thing that might help is working out the impedance of your laptops sound card, and put that in instead of the default.

Tony.

ultrachrome · 20th September 2005, 03:18 PM

I tried using my desktop machine with its cheesy built-in Realtek AC97 sound card and it calibrates fine and I now have accurate looking impedance plots of my tweeter and midrange.

19th September 2005, 05:31 AM	#1
ultrachrome diyAudio Member Join Date: Jan 2002 Location: Puget Sound	Wallin II / SW impedance calib problem I'm having a heck of time peforming the impedance calibration with my jig. My impedance curves for my drivers never dip below 12 ohms for what should be 7-8 ohm drivers. My jig measured out correctly after I built it but I notice that when I have J2 and J3 connected to my sound card (M-Audio Transit USB) and set the jig to 16 or 4 ohm calibration mode that BP3-BP4 measure 31 and 8 ohm, respectively. Is that normal? My other problem is that the calibration process says that I appear to have an open connection. I've tried connecting it to the laptop's internal sound card and have tried different cables but I still keep getting the same error message. Any ideas?

19th September 2005, 03:59 PM	#5
ultrachrome diyAudio Member Join Date: Jan 2002 Location: Puget Sound	******** Wow, that auto-censor is touchy. If you make that word plural, it's a dice game.

20th September 2005, 11:04 AM	#6
wintermute just another diyAudio Moderator Join Date: Aug 2003 Location: Sydney Blog Entries: 22	Did you try measuring again after doing the first calibration? sometimes if the calibration is out it will take a few goes to get a proper reading. The other thing that might help is working out the impedance of your laptops sound card, and put that in instead of the default. Tony. __________________ Any intelligence I may appear to have is purely artificial! Some of my photos

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Wallin jig, sound card and connection problem	JacquesK	Multi-Way	5	19th May 2008 09:48 PM
Switch impedance issues in Wallin 2 Jig	Dave Bullet	Multi-Way	9	28th May 2007 10:13 PM
problem with Wallin preamp 2	wintermute	Chip Amps	10	18th January 2005 07:37 PM
OT impedance problem	m0rg	Tubes / Valves	2	9th July 2004 04:58 AM
Wallin Jig 1 for Speaker Workshop: Wiring Problem?!	Rarkov	Multi-Way	1	12th September 2002 08:18 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

19th September 2005, 08:26 AM	#2
noodle_snacks diyAudio Member Join Date: Mar 2004 Location: Hobart, Tasmania	Have you gone through the process of setting the levels using loop record mode and a sine wave? I found the peaks of the waveform clipping were giving me some trouble in impedance measurements.

19th September 2005, 03:56 PM	#4
ultrachrome diyAudio Member Join Date: Jan 2002 Location: Puget Sound	Looks like it's a problem with my laptop. In the IMPCAL16 mode, the BP3-BP4 resistance measures 32R when plugged into the Transit and 64 when plugged into the laptop's line in. Did the Wallin checkout a second time and found no problem. Took the jig downstairs to my desktop line in and IMPCAL16 meausures 16R just like it's supposed to. Crap. Now I need to drag my desktop upstairs. Girlfriend is not going to like that.

20th September 2005, 03:18 PM	#7
ultrachrome diyAudio Member Join Date: Jan 2002 Location: Puget Sound	I tried using my desktop machine with its cheesy built-in Realtek AC97 sound card and it calibrates fine and I now have accurate looking impedance plots of my tweeter and midrange.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read