Summit Spike Decision

sleepysurf · Apr 14, 2007

sleepysurf said:
... to slide easily on carpet, like these sliding pads available for moving furniture... http://

Doh! I just remembered that I had an old set of furniture sliders sitting somewhere in my garage. Lo and behold, I found them, and they worked perfectly for positioning of the Summits. The one's I have are Easy Mover II's, and have fairly thick foam cushions, which the spikes dug into (without perforating). It was then a BREEZE to slide the Summits around to get the perfect toe-in and distance from front wall. Here's a pic of them in action!

paulo m · Apr 14, 2007

Gordon Gray said:
Look at each string and, if the tilt angle is exactly the same, you should be able to measure the same "offset" horizontal distance from the string to the front of the panel. Measure the horizontal offset distance, at the bottom of the woofer module, from the string line to the front of the panel. Let's call that dimension "x". Now measure the vertical distance from the bottom of the woofer module to the top of the panel where you've attached the string. Let's call that dimension "y". Divide "x" by "y" and hit the tan -1 (may be called "cotan" on some calculators) on your calculator. That result is the tilt angle, from 90 degrees, for the panel.

Before doing the division described above, you must first convert inches to its "decimal" equivalent in feet.

To be accurate, tan^-1 is arctan, not cotan. Cotan is simply y/x. It should be noted that you need to calculate the tangent only if you want to know the angle. The same offset in both speakers will always yield the same angle, so you don't really need any trigonometry to ensure both panels have the same tilt. One final note: There's no need to convert from inches to decimal feet, as long as you don't mix the two. The simplest would be to just use inches. This is because the unit of measurement will cancel out when you do the division.

Joey_V · Apr 15, 2007

sleepysurf said:
Doh! I just remembered that I had an old set of furniture sliders sitting somewhere in my garage. Lo and behold, I found them, and they worked perfectly for positioning of the Summits. The one's I have are Easy Mover II's, and have fairly thick foam cushions, which the spikes dug into (without perforating). It was then a BREEZE to slide the Summits around to get the perfect toe-in and distance from front wall. Here's a pic of them in action!

So... what's the perfect toe in and distance from the wall for your setup, SS?

Joey

sleepysurf · Apr 15, 2007

Joey_V said:
So... what's the perfect toe in and distance from the wall for your setup, SS?

Joey

Well, placement is still limited by my large A/V wall unit and RPTV (hopefully both will be gone by end of year). Summits are now tilted at 93 degrees, 8.5 ft apart (center to center), with panels ~ 4ft from front wall, with moderate toe-in so they're now facing DIRECTLY at me in the "sweet spot" (where I cannot see the sides of the woofer cabinet). For EXACT mirror-image positioning, distances from the rear woofer cabinet top corners to wall are 33" and 37", respectively.

I have a number of FLAC tracks I stream with my Squeezebox, for reference after every change. These include the Chesky LEDR Imaging Test, Jacintha Moon River, Gary Karr Gavotte, Michael Hedges Hot Type, Diana Krall A Case of You, Miles Davis Round Midnight.

jtwrace · Apr 15, 2007

sleepysurf said:
Well, placement is still limited by my large A/V wall unit and RPTV (hopefully both will be gone by end of year). Summits are now tilted at 92.5 degrees, 8.5 ft apart (center to center), with panels ~ 4ft from front wall, with moderate toe-in so they're now facing DIRECTLY at me in the "sweet spot" (where I cannot see the sides of the woofer cabinet). For EXACT mirror-image positioning, distances from the rear woofer cabinet top corners to wall are 33" and 37", respectively.

I have a number of FLAC tracks I stream with my Squeezebox, for reference after every change. These include the Chesky LEDR Imaging Test, Jacintha Moon River, Gary Karr Gavotte, Michael Hedges Hot Type, Diana Krall A Case of You, Miles Davis Round Midnight.

sleepy-
are they 92.5' toward you or away?

sleepysurf · Apr 15, 2007

Tilted slightly BACK (3.0 degrees from vertical).

jtwrace · Apr 15, 2007

sleepysurf said:
Tilted slightly BACK (3.0 degrees from vertical).

OK. I was just curious being it could've been either way.

Gordon Gray · Apr 15, 2007

Thanks for the clarification

paulo m said:
To be accurate, tan^-1 is arctan, not cotan. Cotan is simply y/x. It should be noted that you need to calculate the tangent only if you want to know the angle. The same offset in both speakers will always yield the same angle, so you don't really need any trigonometry to ensure both panels have the same tilt. One final note: There's no need to convert from inches to decimal feet, as long as you don't mix the two. The simplest would be to just use inches. This is because the unit of measurement will cancel out when you do the division.

Paulo,

Agreed on all accounts. One of the purposes of my post was to describe how people could figure the tilt angle if they wanted to know. I've revised my previous post to reflect your corrections. A much easier calculation. I'm just wired as a "civil engineer" and I always convert to feet / decimal equivalents when I do calculations. Sorry to the other members for making this more difficult than it really is.

GG

sleepysurf · Apr 17, 2007

sleepysurf said:
This leads me to another idea. It would be cool to have a granite (or perhaps wood) base for the Summits, that has a teflon (or polymer) coating on the underside, to allow it to slide easily on carpet, like these sliding pads available for moving furniture... http://www.asseenontv.com/prod-pages/Movingmen.html.

Once the ideal speaker position is found, you would then screw in OUTBOARD SPIKES ON THE BASE (raising it slightly) to firmly anchor it to the floor substrate.

The other day, on a whim, I googled "Summit+granite+spikes", and found this site from OregonDV... http://www.oregondv.com/Martin_Floor_Standing_Speaker_Stands_Plinths.htm

I have NO INTENTION of undermining Tgun5's great deal on outrigger spikes for ML's, but was curious, and emailed OregonDV inquiring if they could create a sliding base/spike combo for the Summits. Paul (from OregonDV) sent me the following reply, but my furniture glider solution already turned out to be sufficient for my needs. However (with his permission) I'm posting his reply here, for anybody interested in a more permanent solution...

"We could incorporate adjustable casters into our outriggers that would allow the user to move the speaker into position and then be able to lower until the spikes start penetrating. The outriggers allow for height adjustment on the spike side and the casters would have the same ability. Please let me know if this sounds interesting and I can make up a drawing with pricing."

Gordon Gray · Apr 18, 2007

Another benefit / lower preamp volume settings

Howdy all,

Besides a significant increase in overall transparency and imaging that Jason's spikes have brought (my current tilt angle is about 91.6 degrees or 1.6 degrees "clockwise" or back from perpendicular), I've verified that the volume level of my preamp is now 2 to 3 settings lower than what is was previously, to attain the same volume level. Each setting on my CJ raises or lowers the volume by 0.7 DB. This means an additional 1.4 to 2.1 DB of amplifier headroom, which may be significant for some.

GG

jtwrace · Apr 20, 2007

Gordon Gray said:
Howdy all,

my current tilt angle is about 91.6 degrees or 1.6 degrees "clockwise" or back from perpendicular)

GG

glad to hear. I'm going to try this angle as well. Oh, this would be when your standing on the right of the speaker...

benleeys · Apr 20, 2007

jtwrace said:
glad to hear. I'm going to try this angle as well. Oh, this would be when your standing on the right of the speaker...

Jason,

Just realised something. The amount of tilt is actually related to the height of your seat in the listening spot. Try this - at your listening spot, stand at full height, then slowy lower yourself towards the floor. You will hear the sound change at different levels, especially the brightness.

marck · Apr 23, 2007

I spent some of the weekend tweaking the positioning of the speakers after installing the new spikes.

I could definitely hear an improvement in midrange and imaging - so much so that my friend was convinced the voices were eminating from the center speaker!

I would strongly recommend this tweak. Many thanks again to Jason :cheers:

Btw, has anyone spoken with ML and explained what we have been trying and the results obtained? It may be something that they could experiment with to determine if that would be a beneficial future change.
Rgds
Marc

sleepysurf · Apr 23, 2007

marck said:
Btw, has anyone spoken with ML and explained what we have been trying and the results obtained? It may be something that they could experiment with to determine if that would be a beneficial future change.

I emailed ML requesting "longer" spikes a while back, explaing why, but they declined to make them. Fortunately Jason stepped up to the plate. We'll definitely ask them about why they chose the default tilt when we visit them in June!

marck · Apr 23, 2007

sleepysurf said:
I emailed ML requesting "longer" spikes a while back, explaing why, but they declined to make them. Fortunately Jason stepped up to the plate. We'll definitely ask them about why they chose the default tilt when we visit them in June!

It will be interesting to hear what they say...

stereoman · Apr 23, 2007

Hi:
I e-mailed ML regarding another issue and mentioned the improvement I heard after reducing the backwards tilt. Here is the response I received from Jim Power:

Regarding tilt, to be honest, I have never tried listening to the Summits in any configuration other that the textbook. I will share your observations with Sales and Engineering. Sounds interesting. Hopefully they can give it a listen sometime soon. I know that the listening lab is in very high demand with other projects at the moment but it sounds like something worth trying.

Thanks,

jp

jtwrace · Apr 23, 2007

who needs them to make them if I do???

Hmm. Maybe I could supply ML with all there spike needs.

jtwrace · Apr 27, 2007

still have some 2.5" & 3" Summit spikes if anyone is interested.

jtwrace · Aug 3, 2007

jtwrace said:
still have some 2.5" & 3" Summit spikes if anyone is interested.

this is still the case for all you new Summit owners...

stereoman · Aug 3, 2007

Hi jtwrace:
Thanks again for supplying this great tweak. Here is a picture showing the spikes on top of Black Diamond Racing Jumbo Pits.

Summit Spike Decision

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