Help hanging R150s

Yardman 49

Hello Polk Support & everyone else:

I need to hang four R150s that I have on order.

http://www.polkaudio.com/homeaudio/products/individual/bookshelf/r150/

They would be hung on the walls about 7.5 feet up.

The mounts that I have on order will require me to screw into the back of the cabinets. Here are my questions:

1- how thick is the MDF on the back panel of the speakers: 3/8", 1/2" or 3/4"
2- Instead of using wood screws to screw in from the back of the speaker cabinet, I'm thinking about putting in machine screws from the inside of the cabinets into the bracket adapters. Can I remove the back panel of the speaker cabinets to do this without causing damage to the internal wiring or components?
3 If I need to open the speaker cabinet, do I gain access via what looks to be the four allen head screws in the front panel?
4) If I drill into the cabinets, does this void the warranty?
5) If I open the cabinets, does this void the warranty?

If there are other things that I need to look out for, that would be helpful.


Thank you in advance for you help.

Frank

Erik Tracy

Frank,
What kind of mounts did you buy?

If the speakers have to go up that high, then I'm guessing that you'll have mounts that allow you to point the speakers down into the listening area?

I had a similar issue with the RTI4s I use as surround rears - no side walls to mount them to and so they had to mount from the ceiling.

I used the Omnimount 20.0
http://www.amazon.com/Omnimount-20-0-Stainless-Steel-Speaker/dp/B00006LHDW

The RTI4s rear firing bass port has the keyhole for wall mounting, but what I did was buy some oversized washers, then used the threaded portion of the ballpivot to go into the keyhole with the washers and used the nut to tighten everything up.

That way I did not have to use any screws going into the speaker cabinets.

The ballpivot allowed me to adjust/point the RTI4s for best listening position.

Just thought I'd throw that out - not sure if the R150s have the rear facing port/bracket. But if they do, you may want to reconsider putting screws into the speaker cabinet.

fwiw,
Erik

obieone

^^^+1 to what Erik said. Another consideration, is weight. It sounds like you may be using satellite mounts for bookshelf speakers. I don't recommend that, I like a lot of head room when it comes to weight issues. You don't want those to come loose.
Try Googling 'bookshelf speaker mounts'
Good luck

Yardman 49

Hello Erik and Obiene:

Thanks much for the replies!

In regards to your questions: yes, they are satellite mounts. But they are good for up to 11 pounds. The R150s weigh about 8 pounds. So that's a 30% margin. I think that should be ok. From the looks of the mounts, the swivel heads appear to be quite "beefy"; I agree that I'd rather really overkill on robustness. But I also have to balance that with acoustic and aesthetics considerations in this case. Also, if they are rated for 11 pounds, and have been adequately engineered, their safety margin should be above their rated limit.

Erik: unfortunately, the R150s don't have a keyhole mount (see the pictures of the R150s at the bottom of this reply). I like the solution you used, but I won't have that as an option. Thanks for the idea, though.

Here are the mounts that I would like to use. They are the "Pinpoint AM20" mounts sold by Crutchfield

(http://www.crutchfield.com/App/Product/Item/Main.aspx?g=15830&i=121AM20B&c=9&tp=2727):







The long 100mm shaft on these Pinpoints can also be used to make the mount longer (as can be seen in the last photo). The mount can be used for ceiling or wall, and seems much more secure than the Omnis. Also, as you can see from the photos, there are two different types of bases (J-Box adapter plate or flat surface mount). This would work well for me, as I have reinforced my J-boxes on the studs, and I could easily hang 8 lbs off of them.

I currently use Omni 10s for my existing satellites (Polk RM101). I don't like the polymer ball system on the Omni 10s. It's harder to keep them from moving when the speakers have any real weight to them, and you need them to hold a set angle.

The problem is that I'm really limited without tearing open my walls, or moving the speakers to stud locations where I don't want them. I know that I could use the B-Tech BT77s that Crutchfield sells. But this would be as a last resort for me:





Also, these B-Tech mounts only have 7 degrees of tilt. I'd like to have a little more than this, since the satellites are up near the ceiling.

**************************************************

Here are photos of the R150s:





It looks as though the grill mounts are some sort of allen or torx head screw. If I remove them, does that allow the back of the cabinet to be removed?

***********************************************

So I guess that my main questions are in regards to how to properly open the R150s, and also if doing so will negate the warranty. If anyone can answer these questions, it would be helpful indeed.

Thanks again,

Frank

Erik Tracy

Bummer about no bracket on the back of the R150's.

Looks like the bracket you've picked is rated to hold the R150s - and with no keyhole - you'll just have to use the screws to mount the bracket on the back.

I also use the same B-Tech mounts for my RTI4s as fronts - great product, but my speakers are mounted much lower than your setup - sometimes the room constraints can be frustrating, eh?

Good luck,
Erik

Yardman 49

Hello all:

I just wanted to give an update on hanging my Polk R150s.

I was able to use the two-point mounting adapters that came with the Pinpoint AM20 brackets. I mounted the adapters vertically to one side of the binding post plate. I simply removed the two wood screws on that side of the plate, and replaced them with longer screws that secured the adapters to the binding post plate.

This arrangement is very secure, thanks to the MDF used on the cabinets. But it does position the adapter off-center to the back of the cabinet. (I had other reasons than not wanting to add new holes to the speaker cabinet. It was really due to the mounting constraints of my room.)

The AM20's are robust enough that this doesn't cause a problem. But what did cause a problem was that on one wall I needed to use the supplied 100mm post (usually used for ceiling mounting), and then had to turn the speaker almost perfectly sideways to the wall. This put a lot of torque on the mounting post.

It's indeed a weird situation that I have with this one speaker. Because of the way the room is laid out, it has to mount on a side wall, rather than on the front wall where my other front speaker is located.

The articulate joint of the AM20 handled this challenge acceptably, holding the speaker at about a 20 degree sideways horizontal angle to the wall. I had to very securely tighten all the set screws on the articulated joint. But it worked. The joint is pretty robust.

But the excess torque caused the 100mm mounting post to start to turn in the flat-sided hole in the j-box mounting plate (I have reinforced my j-boxes, so they can hold the speaker weight with no problems).

This did not happen as much with the wall/stud mounts that come with the AM20s, because the metal on those mounts are thicker than the j-box plates.

I solved the problem by using a small amount of epoxy when assembling the post to the j-box plate, and also using a larger washer under the post binding nut. This solved the post torsion problem completely.

Considering that I was using these mounts in ways that the manufacturer never intended, I was actually pretty pleased with the outcome. They are much less obtrusive than the BT's. But for may application, I would not go any heavier than these speakers with the AM20 mounts. I think that my R150s weigh about 8 lbs apiece.

If I get a chance, I'll post a photo.

Best wishes,

Erik Tracy

Glad you got the speaker mounting figured out.

For some room layouts you do have to get creative in placement and 'adapting' commercial products to work for your application.

Keep us posted and get that picture!

Now, sit back and enjoy the enveloping goodness of Polk sound!

Cheers,
Erik