Infinity Column II Speaker Grill Build

[Zenith4me 1,480]

Hello all,

 

I’m working on a set of Infinity Column II speakers. So far, I’ve refinished the cases, refoamed the woofers, and rebuilt the crossovers.

 

The speaker grills were MIA when I bought these speakers so I’m going to need to build new ones.

 

Just so I don’t try to reinvent the wheel has anyone ever built speaker grills? If so, any advice would be appreciated.

 

The original speakers used a primitive form of Velcro to mount the speaker grills and I’d like to update that method with rare earth magnets.

 

I’m considering just a basic pine rectangle with a brace in the middle since the grills are fairly large. 

 

Anyway, you can’t have enough projects!

[stereo_dog 1,218]

Post pics when you can. I have a pair of the Infinity 2000, same hard velcro-like mounting. The grills on mine have an MDF frame, pretty heavy and rigid. 

[timmyjim 449]

Iv'e used these in the past, very strong, a bit pricey:

 

https://www.parts-express.com/Neodymium-Disc-Magnet-3-8-x-3-16-320-016?quantity=1

 

They used to sell in a set of 4, but now seems to be individual.

[BobTFM35 2,767]

@timmyjim Another alternative web site for magnets of different shapes and sizes.

 

 Strong rare earth neodymium magnets | K&J Magnetics (kjmagnetics.com)

 

Neodymium Magnets | K&J Magnetics (kjmagnetics.com)

 

 

Edited February 1, 2024 by BobTFM35

[3M_Audio 2,023]

I've built several speaker grills in the past. I used poplar for the frame with lap joints at the corners and depending on the speaker outer case, I either left the corners and edges square for a flush setup or when the grill was full-face, I usually rounded off the inner and outer corners to minimize phase and edge diffraction effects. Good quality grill cloth stretched and stapled over the frame finished very nicely.

 

In addition to magnets, standard speaker pegs like Parts Express sells work well for holding everything in place without adding any extra depth.

[Kurt 2,899]

I've used magnets before.  They can work great.  A few lessons learned: 

 

Make sure you note polarity if you are using magnet for both sides of the attachment.  I started out with a magnet on one side, metal on the other side and realized the attachment wasn't strong enough.   So, I went to a magnet to magnet connection in the four corners of the speaker grill.  This worked great on 3 corners of the grill.... the fourth corner not so much because I had inadvertently installed the polarity to be in opposition... 

 

You have to make sure that the attachment of the magnet to the frame is a stronger bond than the force needed to pull the grill off, else you will rip the magnet out of the frame instead of detaching the frame from the speaker.  I tried press fitting the magnets into a hole in the frame.  This was tricky... the hole size is critical.  Too small and you risk cracking the magnet trying to press it in...too big and the magnet will fall out when pulling the grill off.  I ended up using epoxy.   This worked.  Except, I made the mistake of not securing the magnets in place while the epoxy cured and I had a screwdriver sitting close to one of the magnets.... the attraction of the magnet to the metal screwdriver pulled the magnet out of position before the epoxy cured it in place.  So, I had to redo that one.  I used tape over top of the magnets to hold it in place on the try (and made sure no other magnets or metal were close by).

 

I eventually got it right.  You will too.  I think magnets are a good way to go.  Velcro is too cheap feeling.  You can buy the actual plastic/rubber male and female ball/socket connectors on line.  But, using them means you'd have to drill holes in your speaker...something a lot of folks don't want to do.

 

Have fun and post pictures!

[PMAT 2,038]

Be careful of wood selection. Solid wood can easily warp with weather changes. MDF is preferable for flat builds like this. If you use solid wood look for lumber that is quarter-sawn. If the lumber is laying flat on a table you want the grain lines vertical when looking at the end of the board. Avoid curved grain and horizontal grain. The species is secondary. Avoid getting a wide board and ripping several lengths from it. The tension in the board may be released and warp immediately or later. Good luck!

[Ar9Jim 6,512]

Magnets and hardware of many types. Industrial supplies.

 

https://www.mscdirect.com/browse/tn?searchterm=Rare Earth Disc %26 Cylinder Magnets&tg=Matching Categories&rd=k

 

[Kurt 2,899]

One more tip... along the same lesson learned of bonding magnet to frame.... I bought these kind of neodymium magnets from home depot, first.  The foam adhesive backing is not nearly strong enough to attach the magnets to the frame.  Don't waste your money on magnets that come with adhesive backing.

 

[Zenith4me 1,480]

22 hours ago, Kurt said:

Have fun and post pictures!

 

Here's some pictures. The case with the plastic sheeting on it is in the process of being painted. The other case has not been painted and you can see the faint outline of where the old Velcro style tabs were located.

 

 

[stereo_dog 1,218]

Looks good. Were those painted originally?

[Zenith4me 1,480]

2 minutes ago, stereo_dog said:

Looks good. Were those painted originally?

 

Yes, the front (where the speaker grill is attached), the top, and the back were painted. I refinished the sides as can be seen in the pics.

 

I'm in the process of painting the one that you see with the plastic covering the part not to be painted.

 

I bought these from a thrift shop and they were totally disassembled when I bought them. The speakers and crossovers were in a box next to the cases. No speaker grills. The cases had varnish on them. I was amazed at how nice the veneer was after removing the varnish. 

 

BTW....I hooked up the speakers to one of the rebuilt crossovers and they sound great. 

 

If I can ever get past my honey do list I'll be finishing these up.....lol.

[stereo_dog 1,218]

They will look good. A nice score. I've got a set of Altec Valencias that I picked up a few years back. I've built new crossovers and they sound great, but the cabinets are terrible. The guy had them in his basement and let his dog pee on them... needless to say, they sat in my garage for a year before I brought them into the house. I need to rebuild the cabinets, but, they're huge and I don't have much space in the garage to work on them. Maybe this Spring. Enjoy the Infinitys.

[stereo_dog 1,218]

Do you have the glass tops?

[Zenith4me 1,480]

1 hour ago, stereo_dog said:

Do you have the glass tops?

 

No, I wish I did. I think that were tinted and thick glass. I've priced custom tinted glass cut to fit and let me just say it isn't cheap. I paid $75 for the speakers and the glass was ~$500. 

 

I'm thinking about alternatives such as plexiglass. 

[4krow 6,590]

This went deeper than I had anticipated. You found these in unlikely place for an unlikely price. Glass tops may fall into your lap. Don't go out for quotes, go hunting instead. I am not that big into trying to find what I need just anywhere, but then sometimes I end up at this recycling type store with OMG results. You have done this much on a chance. Either local or some weird little place you wouldn't normally think of. 

[4krow 6,590]

Looked on eBay for the hell of it. This may not be real glass, but I saw chip in it and then wondered if it might be. WTH is poly glass?

 

 

Look at 1/4" Thick Tinted Rectangle Poly Glass Window      It is for a boat. It costs $29+$9 for shipping. It is a pair. Sorry that I cannot be of help for links and crap like that.

 

 

[Zenith4me 1,480]

1 hour ago, 4krow said:

This went deeper than I had anticipated. You found these in unlikely place for an unlikely price. Glass tops may fall into your lap. Don't go out for quotes, go hunting instead. I am not that big into trying to find what I need just anywhere, but then sometimes I end up at this recycling type store with OMG results. You have done this much on a chance. Either local or some weird little place you wouldn't normally think of. 

 

I'm in no big hurry to get glass for it. I saw a pair of these speakers in San Diego and they had cut a thick piece of wood to fit in that area and then a normally priced piece of standard glass on top of that. Where it starts getting expensive is when you buy bronzed glass with polished edges.

[Receiver2000 4,014]

Those look good the way they are but very cool with the glass.

[Receiver2000 4,014]

I have these HK-50's with a stone top. I don't know what they were thinking - to set a drink or potted plant? Anyway, a piece of stone or porcelain might be options as well.

[Zenith4me 1,480]

Stone...that is wild. 

 

Lot's of options to consider. I'm not that big of a purist. 

[Receiver2000 4,014]

This is the way the HK-50 is set up. Omnidirectional.

[stereo_dog 1,218]

3 hours ago, Zenith4me said:

 

No, I wish I did. I think that were tinted and thick glass. I've priced custom tinted glass cut to fit and let me just say it isn't cheap. I paid $75 for the speakers and the glass was ~$500. 

 

I'm thinking about alternatives such as plexiglass. 

Try One Day Glass on the internet. I had some glass bases made for my Silver 9t's, (4) for around $185... I think.

[Sk1Bum 11,404]

Granite, slate, the right ceramic tile, corian...

[BobTFM35 2,767]

Project is looking good. Several good options for the top, to top it off.

 

Found this for the grills..

Speaker Grill Peg Mounting Kit, Ball And Socket, 8 Pack, GC-SMPEG (simplyspeakers.com)

 

Speaker Grill Peg Repair Kits (simplyspeakers.com)