DIY phase plug, snug fit or not?

jamesdb · 19th June 2007, 06:16 PM

When making a DIY Phase plug, should the plug fit very snugly against the hole, or should there be a tiny gap/free space between the sides of the plug and the hole of the paper cone? Thanks

MarkMcK · 20th June 2007, 03:07 PM

The inside of the voice coil former should not rub against the sides of the plug. The tolerances for VC former ID and plug OD do not have to be extremely tight. At some point, however, the gap will contain enough air to resonate at audible frequencies. So, the voice coil must be able to move freely. A small gap between the VC former ID and the plug OD is fine. A large gap, however, is not fine.

I usual chose a ratio of VC former ID and plug OD that allows free motion of the VC to the mechanical excursion limit of the transducer. Keep in mind that as you approach the excursion extremes you will get some drift in alignment.

As a rule of thumb, if you use the pole piece OD for your plug OD you will be fine on all counts.

Best on your quest for better sound,

Mark

jamesdb · 20th June 2007, 08:34 PM

much appreciated

19th June 2007, 06:16 PM	#1
jamesdb diyAudio Member Join Date: Jun 2007	DIY phase plug, snug fit or not? When making a DIY Phase plug, should the plug fit very snugly against the hole, or should there be a tiny gap/free space between the sides of the plug and the hole of the paper cone? Thanks

20th June 2007, 08:34 PM	#3
jamesdb diyAudio Member Join Date: Jun 2007	thanks! nt much appreciated

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
Phase Plug, how does it works?	Antonio	Multi-Way	5	17th June 2009 12:05 PM
Phase plug seems to make a new BSC necessary.	G	Full Range	3	28th March 2008 06:05 PM
making a phase plug?	nerd of nerds	Multi-Way	27	25th April 2007 03:25 PM
Phase Plug Dims ?	valveitude	Full Range	0	16th November 2006 03:10 PM
Anywhere to buy off-the shelf phase plug?	bcherry	Full Range	6	19th October 2005 07:22 AM

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

20th June 2007, 03:07 PM	#2
MarkMcK diyAudio Member Join Date: Aug 2003 Location: Ohio	The inside of the voice coil former should not rub against the sides of the plug. The tolerances for VC former ID and plug OD do not have to be extremely tight. At some point, however, the gap will contain enough air to resonate at audible frequencies. So, the voice coil must be able to move freely. A small gap between the VC former ID and the plug OD is fine. A large gap, however, is not fine. I usual chose a ratio of VC former ID and plug OD that allows free motion of the VC to the mechanical excursion limit of the transducer. Keep in mind that as you approach the excursion extremes you will get some drift in alignment. As a rule of thumb, if you use the pole piece OD for your plug OD you will be fine on all counts. Best on your quest for better sound, Mark