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[Peter Kowalczyk]

Has anyone else had trouble with their M20 threaded Pole Cups?

I use Meyer X40 and 900-LFC with a single threaded pole, and found that setup was a bit wobbly, and that wobble led to one pole cup failing. A colleague had the same issue. So, I came up with a more robust solution and had these Truss Adaptors built. 

I'm posting to see if there's enough interest in the community to build a small batch to share. 
Mods, please move to a more appropriate forum if necessary....

These adaptors work with 35mm (1-3/8") pole cups that have an integrated M20 threaded socket, such as Penn-Elcom M1557/M20
https://www.penn-elcom.com/us/universal-speaker-mounting-top-hat-m1557-m20

These pole cups are standard on some Meyer Speakers, but I'm guessing are common with others, and are likely an easy retrofit for others still.

These adaptors use an off-the-shelf Global Truss F34 12" square base plate, with a 35-mm aluminum tube welded on. An M20 bolt fits through the tube to secure the speaker to the plate.

The end result is basically a Global Truss SQ-4137SAP with an M20 hole through the middle, except that the 'Speaker Pole' stud is welded instead of bolted on to allow for the coaxial hole.

I put a pair of these adaptors on each end of a stick of truss. I use 1.25m segments, naturally you can pick whatever length suits your need. Each end bolts securely into its respective speaker. The 12" footprint is far more stable than a single pole. Plus they look pretty cool 😎.

My cost for the first round was about $400 / pair in a batch of 8x. That includes a pair of plates, pair of bolts and washers. If there's enough interest and we can run a larger batch, we can hopefully get the cost down a bit. If you're interested in getting a set, please DM me (info <AT> sierraaudiosolutions <DOT> com) and we can talk!

Thanks!

PK

[Peter Kowalczyk]

... Addtional Photos...

[Scott Helmke]

Very cool, but seems a bit overkill? 

We ended up putting M20 pole sockets in the tops of our small Meyer subs, and bought some of the K&M speaker poles that have M20 on the bottom and 1-3/8" on top.

[Jeff Lelko]

Maybe I’m missing something, but why not just put an M20 bolt through the middle of the plate straight into the cup?

[Peter Kowalczyk]

Very cool, but seems a bit overkill? 

We ended up putting M20 pole sockets in the tops of our small Meyer subs, and bought some of the K&M speaker poles that have M20 on the bottom and 1-3/8" on top.

Oh, its definitely overkill.   

However, after having an M20 pole cup fail at a gig, I don't trust the straight poles anymore.  The weight of an X40 on top of a straight pole was able to apply enough torque to break a pole cup. Can you imagine with a UPQ?  These truss assemblies feel solid with a UPQ on top of a 900LFC.

[boburtz]

Has anyone else had trouble with their M20 threaded Pole Cups?

The end result is basically a Global Truss SQ-4137SAP with an M20 hole through the middle, except that the 'Speaker Pole' stud is welded instead of bolted on to allow for the coaxial hole.

I put a pair of these adaptors on each end of a stick of truss. I use 1.25m segments, naturally you can pick whatever length suits your need. Each end bolts securely into its respective speaker. The 12" footprint is far more stable than a single pole. Plus they look pretty cool 😎.

I did this with F14 truss, which still has a very small visual footprint, but much more stable than a pole. This is an RCF NX-L24a on top of a JBL SRX818.

[Robert Lunceford]

Oh, its definitely overkill.   

However, after having an M20 pole cup fail at a gig, I don't trust the straight poles anymore.  The weight of an X40 on top of a straight pole was able to apply enough torque to break a pole cup. Can you imagine with a UPQ?  These truss assemblies feel solid with a UPQ on top of a 900LFC.

What did Meyer Sound have to say about the pole cup failure?

[Jeff Lelko]

However, after having an M20 pole cup fail at a gig, I don't trust the straight poles anymore.  The weight of an X40 on top of a straight pole was able to apply enough torque to break a pole cup. Can you imagine with a UPQ?  These truss assemblies feel solid with a UPQ on top of a 900LFC.

Is that plastic?!  Very frightening if so.  I get that manufacturers are trying to shave weight and cost where they can but this seems to be a very poor place to do that...

[Chris Hindle]

Is that plastic?!  Very frightening if so.  I get that manufacturers are trying to shave weight and cost where they can but this seems to be a very poor place to do that...

May be aluminium, but I'm betting on white metal.
Chris.

[John Schalk]

In the picture of the broken pole cup, is that some kind of dual mode cup?  The M20 mounts on my subs are flush with the speaker cabinet such that the bottom of the air-assisted poles that I use make contact with the metal plate of the M20 mount when screwed down tightly.  IOW - there's no "cup" at the bottom, just a solid metal plate.  I've never felt like my speakers were wobbly on my poles.  I agree that the speakers do look cool mounted on the truss!

[ProSoundWeb Community]