You are here

Focal Tweeter Phase Plugs

For everything after the recording stage: hardware/software and how you use it.

Focal Tweeter Phase Plugs

Postby Mick C » Tue Jan 26, 2016 7:46 am

I'm looking for a pair of monitors and I've noticed that the Focal CMS range ship with a Tweeter Phase plug. You remove the protective mesh grille from the tweeter and fit this small (flimsy) plastic thing in its place.

Does anyone know what it does, how it works, and is it necessary? I've got young kids so I'd prefer to keep the protective grilles in place!
Mick C
Regular
Posts: 77
Joined: Tue Oct 26, 2010 12:00 am
Location: Manchester, UK.
Mick

Re: Focal Tweeter Phase Plugs

Postby Random Guitarist » Tue Jan 26, 2016 9:50 am

As I understand it the phase plug is intended to help with even sound dispersion. I have the CMS-40s as a second pair of speakers, but have never used them without the plug. I do know they don't sound as good with the grill in place. One thing to bear in mind is the plugs are only a push fit s I don't know if you could repeatedly swap plugs and grills without degrading the fit.

Perhaps you could make some kind of case to slip over the speakers to protect them when not in use?
Random Guitarist
Frequent Poster
Posts: 692
Joined: Tue Apr 01, 2008 12:00 am
Location: West Sussex UK
I've never liked a solo violin, you need at least five for a proper fire.

Re: Focal Tweeter Phase Plugs

Postby Hugh Robjohns » Tue Jan 26, 2016 1:24 pm

Mick C wrote:Does anyone know what it does, how it works, and is it necessary?

It controls the HF dispersion from the tweeter. Without it the stereo imaging will be significantly compromised.

H
User avatar
Hugh Robjohns
Moderator
Posts: 28945
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Focal Tweeter Phase Plugs

Postby MarkOne » Tue Jan 26, 2016 1:42 pm

Hugh Robjohns wrote:
Mick C wrote:Does anyone know what it does, how it works, and is it necessary?

It controls the HF dispersion from the tweeter. Without it the stereo imaging will be significantly compromised.

H

Why on earth don't they just factory fit them then?
MarkOne
Frequent Poster
Posts: 1203
Joined: Thu Feb 15, 2007 1:00 am
Location: Bristol, England, Earth, Perseus Gap, Milky Way
Debut Album 'Fantasy Bridge' available now!

Re: Focal Tweeter Phase Plugs

Postby Hugh Robjohns » Tue Jan 26, 2016 3:10 pm

Probably because they tend to get damaged when the speaker is removed from the carton...

H
User avatar
Hugh Robjohns
Moderator
Posts: 28945
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Focal Tweeter Phase Plugs

Postby Mick C » Wed Jan 27, 2016 4:59 pm

Thanks for your input guys.

I ended up buying the CMS 50 as they were the best sounding compared to the others I tried (to my ears anyway). I'm now running them in so it'll be interesting to see the effect of the phase plug afterwards.

For reference I compared against Adam 5X, Genelec 8030B, Genelec M030, plus the next size up for each of these types.
Mick C
Regular
Posts: 77
Joined: Tue Oct 26, 2010 12:00 am
Location: Manchester, UK.
Mick

Re: Focal Tweeter Phase Plugs

Postby mmathieu » Fri Nov 20, 2020 6:32 am

Re: Focal CMS monitors with phase plugs.

Thanks Hugh for the short and excellent direct answer. Comment: The phase plugs do control the dispersion and should be used and/or retro-fitted if possible. The grills are for protection and they detract from the performance of the tweeter as would be expected by how they are constructed.

I comment at this late date as a Focal CMS50 user and I can assure you that the number of used monitors you see for sale with damaged tweeters is overwhelming! MAYBE, in addition to contributing to good dispersion, the phase plug can keep fingers and equipment from ruining a delicate (and EXPENSIVE) high-tech tweeter. Hope, hope.

I comment because these monitors are "little" gems and highly recommended for use within their "near-field" and shear SPL limits.

Good luck,
MMathieu, Advanced Audio Engineering
mmathieu
New here
Posts: 6
Joined: Tue Jul 13, 2010 12:00 am
Location: California, USA