John Sayers' Design Forum

John Sayers' Recording Studio Design Forum

A World of Experience
Click Here for Information on John's Services
It is currently Tue Nov 30, 2021 10:28 am

All times are UTC + 10 hours




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Sun Feb 12, 2006 4:10 am 
Offline

Joined: Sun Feb 12, 2006 3:16 am
Posts: 63
Location: Sweden
Hi there!!

Anybody with experience regarding soffit-mounting of the Genelec 8050's?? Genelec is about to release a kit for that purpose. What bothers me is the pricing of that kit ( 650 Euros).

The shape of the speaker and the fact the the bass-port is on the rear-end makes it difficult...

Cheers,
Ola


You do not have the required permissions to view the files attached to this post.


Report this post
Top
 Profile  
 
 Post subject:
PostPosted: Sun Feb 12, 2006 7:04 am 
Offline
Senior Member
User avatar

Joined: Sun Mar 16, 2003 11:11 am
Posts: 6976
Location: West Coast, USA
That flush mount kit sounds to me like a serious attempt at theft; when they first came out with that series I just thought they were intended ONLY for free-standing use - the rounded edges, etc, will lessen diffraction effects but make it really difficult to get a flat plane baffle extension. But 650 euros is more than some people pay for their speakers in the first place :evil:

If I were going to attempt to flush mount those, and didn't want to pay so much, here's what I'd try -

Build the soffit enclosure and leave a cutout larger than the largest speaker I'd ever plan to install.

Cut out a blank front panel (bezel) that just fits the larger opening.

Lay the speaker face down on top of the blank bezel, centered where you want it to be.

Mark a cutout around the perimeter of the speaker; angle the pencil so that the resulting cutout will allow the FULL size of the speaker cabinet to fit into the resulting hole in the bezel.

Cut out on the marks you made (a saber saw, otherwise called a portable jig saw, works best), and clean up with sandpaper (coarse only; you're not done yet.)

Lay the speaker on its back, drivers up, and wrap it snugly with at least 3 layers of plastic food wrap.

Place the cutout bezel over the speaker, and make sure it comes to rest with about 10-12mm of the speaker projecting forward through the face of the bezel -

If the speaker doesn't protrude EVENLY at all corners, find some spacers (like wood blocks) to put under that corner of the bezel until the speaker is EVENLY protruding through the bezel by about 10-12mm.

Don't panic; we're not finished yet, I know the baffles should be in the same plane...

If your cutouts are 90 degrees to the face of your bezel, there should be a tapered GAP all around the face of the speaker that is wider at the FRONT of the bezel.

Mix a batch of patching plaster (the Fixall brand is good) and carefully fill the GAP around the speaker box, being careful NOT to tear the layers of plastic wrap protecting the speaker box. Let this dry for at least TWICE as long as the directions recommend.

Remove the speaker from the bezel and use medium or fine sandpaper to clean up the edges of the hole in the bezel. Remove the plastic food wrap from the speaker.

Now, when you hold the bezel up to the speaker and use a straight edge to ensure that the two are FLUSH at the front, there should be a uniform but SMALL (6mm or so) gap all around the speaker box edge.

Cut a heavy shelf large enough for the speaker to rest on, and cut two equally heavy support gussets to support this shelf; glue/screw the two together, and mount the shelf to the front bezel so your speaker can sit on the shelf and maintain the EVEN gap around the perimeter; you should fill this perimeter gap with insulation, pressed in until it's even and flush with the front. This will treat any high frequency diffraction due to the small crack between the speaker box and the bezel.

If the feet on the speaker keep you from positioning the face so it's FLUSH with the face of the bezel (and they might) you will need to rout out a couple of pockets at the front of the shelf and into the face of the bezel to let the feet clear. This can be done with a router, or maybe a wood-carving gouge or a rotary rasp on an electric drill.

Also, if the feet aren't soft rubber designed to decouple the speakers (I've not seen these so don't know) you would need to allow for a pad under the speakers to accomplish decoupling.

I've done a simple sketch showing only the basics, hopefully the idea comes across... Steve

(Now, we BOTH understand why the 650 euros... :?


You do not have the required permissions to view the files attached to this post.

_________________
Soooo, when a Musician dies, do they hear the white noise at the end of the tunnel??!? Hmmmm...


Report this post
Top
 Profile  
 
 Post subject:
PostPosted: Mon Feb 13, 2006 12:13 am 
Offline

Joined: Sun Feb 12, 2006 3:16 am
Posts: 63
Location: Sweden
Thanx for your reply Steve!!

Well, you got a point there. The 8050's are made for free standing use. Maybe it's meaningless to soffit mount them?? Read some posts on this forum where someone really questioned the benefits of that (Just having it for looks to impress the clients). Maybe our ears are tuned to the sound of a free standing speaker??

Got to consider it...

Cheers,

Ola


Report this post
Top
 Profile  
 
 Post subject:
PostPosted: Thu Jun 29, 2006 7:56 pm 
Offline

Joined: Thu Jun 29, 2006 7:50 pm
Posts: 1
Hi,

Because of the cabinet shape you don't actually benift (acoustically this is) by sofit mounting them. So....

If you want the speakers out of the way just mount them on a shelf on the wall in the right place. The 8050's have enough control DIP switches on the back to compensate for this position.

Ste


Report this post
Top
 Profile  
 
 Post subject:
PostPosted: Thu Jan 24, 2008 3:07 pm 
Offline
Senior Member
User avatar

Joined: Sun Mar 16, 2003 11:11 am
Posts: 6976
Location: West Coast, USA
I don't agree with this at all - although the rounded design will improve diffraction of mids/highs over hard, square edges, it will NOT keep low frequency modes from being more complex than necessary - only flush mounting in a properly shaped room/soffit construction will do that.

I received a PM with a link to the available kits for soffiting, if you have the $$ -

http://www.genelec.com/documents/other/ ... t_kits.pdf

Only thing I might add to my "workaround" would be a port extension, exiting under the speaker box - although since flush mounting tends to increase bass response, I'm not sure without hearing it whether the port extension would be necessary... Steve

_________________
Soooo, when a Musician dies, do they hear the white noise at the end of the tunnel??!? Hmmmm...


Report this post
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 5 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group