Primitive harmonic distortion test of Dayton DVC 8"

arjscott · 16th February 2007, 08:40 AM

Hi all,

I'm seeking opinions on the results below. To my relatively untrained eyes this looks like 3rd order harmonic distortion 10 dB down from the fundamental frequency. And also 5th order 20 dB down, 7th order 30 dB down.

The first result shows the measured response playing a 50Hz sinewave, and the second is 100Hz. Obviously all I'm doing here is using TrueRTA. Is this a valid test?

I have to admit I have been using it for a few weeks in a temporary enclosure, and at usual low listening volumes this distortion is not obvious to me.

I suppose I can't complain about the performance of a US $23 driver, but I was expecting the distortion to be a little lower than this.

Andrew.

arjscott · 16th February 2007, 08:41 AM

Second pic

Ron E · 19th February 2007, 12:06 AM

What is the drive level?

-10dB is ~30% distortion

That is pretty high for 100Hz - you may want to make sure you are not overdriving your microphone or clipping the input signal from having the mic gain too loud. Experiment with mic gain settings, if turning down the gain gets you lower distortion you are overloading your inputs.

arjscott · 19th February 2007, 05:16 AM

Hi Ron,

Thanks for your response. You were right. I had the mic a little closer than normal to the speaker, and I didn't think to check this.

What an idiot... Well I'm pleased the driver's distortion is nowhere near this level.

Andrew.

19th February 2007, 12:06 AM	#3
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	What is the drive level? -10dB is ~30% distortion That is pretty high for 100Hz - you may want to make sure you are not overdriving your microphone or clipping the input signal from having the mic gain too loud. Experiment with mic gain settings, if turning down the gain gets you lower distortion you are overloading your inputs. __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

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
Harmonic Distortion In Maggies	JimOfOakCreek	Planars & Exotics	2	20th April 2008 04:04 AM
Why is distortion harmonic?	dsavitsk	Tubes / Valves	48	12th March 2008 02:49 AM
What effect does a TL have on harmonic distortion?	owdi	Multi-Way	0	26th April 2006 03:55 PM
second harmonic distortion	tenderland	Tubes / Valves	5	5th August 2004 11:29 AM
Non Linear Distortion testing - Harmonic Distortion	JMB	Multi-Way	0	20th July 2004 02:54 PM

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


	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 February 2007, 05:16 AM	#4
arjscott diyAudio Member Join Date: Apr 2006 Location: NZ	Hi Ron, Thanks for your response. You were right. I had the mic a little closer than normal to the speaker, and I didn't think to check this. What an idiot... Well I'm pleased the driver's distortion is nowhere near this level. Andrew.

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