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Cornwall riser replacment tweak


No Disc

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For some time now I've been experimenting with riser replacements and surfaces to place my Cornwalls on. Before I started this quest I felt the stock Cornwall bass was a bit sloppy and the presentation lacked a bit of focus. (my opinion).

Based on a a simple suggestion from Mobile Homeless I began to experiment with different methods of getting the Cornwall off the floor (de-coupling). First with tennis balls cut in half and then with vibrapods. Each time the sound improved so I knew I was on the right track. Each of those tweaks improved the bass so that it was better controlled and less muddy.

After researching further I discovered that coupling, not de-coupling was the answer. I ordered a custom maple 3" thick stand from Timbernation to act as the riser and coupling point. I also ordered brass triplepoint footers from Mapleshade records to couple the Cornwalls to the maple riser.

The results were just what I was hoping. Everything came into focus. Gone was the muddy bass, and each instrument was clear and distinct in the soundstage. The improvment was so drastic that I was was awestruck. I believe the improvement is due the vibrational energy and cabinet resonance that without coupling, have no where to dissapate thus blurring the sound. Coupling the Cornwall to a solid foundation allows the resonance to dissapate into the foundation.

This may be too radical a idea for some of you, but for me, it was just the ticket to sonic bliss. I'm never going to put my stock risers back on, I know that for sure.

No Disc

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Allan you sent me pictures of your setup a while back when I first started thinking about this.

The difference in your setup that I can tell is that your using a soft cushion between the cornwall bottom and the riser. My setup is different in that I am hard coupling the cornwall to the maple riser.

I believe your approach is more of de-coupling than coupling. A improvement over stock for sure. In my opinion, coupling is better still, at least for my floor setup which is carpet over cement.

No Disc

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On 3/11/2005 8:13:02 PM Allan Songer wrote:

I've been doing this for the last 6-7 years. It works. The only difference with my set up is that I use sand-filled walnut and steel risers that mimic the factory risers.

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NOPE! There is nothing between my Conrwalls and their risers. I have no carpeting under mine and they sit on hardwood floors on a raised foundation. My risers are mass loaded to the floor with spikes and the Cornwall sits on the riser. I'll bet my system works pretty much the same as yours.

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If thats the case then yes it works the same although the coupling methods are somewhat different. The pictures you sent me showed strips of felt or cushion material on top of the riser you made. You had said this was to protect the bottoms of the cornwalls from being damaged.

My understanding is that any soft material between the risers and Cornwalls would act as a de-coupler instead of a coupler.

If you have changed that configuration great, would be an improvement in my opinion. Although the bottoms of the Cornwalls might suffer slightly, it would be offset by the sonic improvement.

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On 3/11/2005 8:54:52 PM Allan Songer wrote:

NOPE! There is nothing between my Conrwalls and their risers. I have no carpeting under mine and they sit on hardwood floors on a raised foundation. My risers are mass loaded to the floor with spikes and the Cornwall sits on the riser. I'll bet my system works pretty much the same as yours.

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No Disc.

Very Nice.

Just last night I was listening to my system and decided I needed to raise my Cornwalls about 6 inches off the ground. This would get my tweeters about ear level.

With your mod, about how much did it raise your speakers?

Again very nice.

Danny

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Moon,

I'm not a scientist and don't have a full understanding of the physics involved. I only know it works.

If your truly insterested in knowing why this works, contact Pierre Sprey at Mapleshade and can explain the hows and whys. He's a scientist and is a huge advocate of this approach.

Email tweaks@mapleshaderecords.com or call 301-627-7922.

Also I don't feel just getting the speaker off the floor is the key, but rather coupling the speaker to the floor. In this case the mechanical grounding provides resonance control. It drains the vibrational energy out of the speakers enclosure and into the stand, or floor below. The better the coupling the more energy that is removed and less muddy the sonics will be. This is dependant on what type of flooring you have.

No Disc

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This does work.

I raised my lascalas 14 inches off the ground. I built platforms filled with sand.

The tweeter was at ear level and the bass just sounded so much tighter and full.

I didn't spike them, but I did spike my KLF20's and this also made a difference.

I also think it helped because I am living in a one story house with a crawl space underneath. I think by building the platform it helped reduce vibration going to the floor.

Again nice tweak. How did you go about ordering the platform. I built mine out of 2x4's and plywood. Your idea is just so much nicer.

Danny

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Danny,

Both MapleshadeRecords.com or timbernation.com can make solid maple risers. I got mine from Chris at Timbernation. I just gave Chris the size, thickness and finish I wanted and he did the rest. The brass spiked cones are from mapleshade. If your going to experiment more I would also suggest you call Pierre at mapleshade before going further.

No Disc (Tim)

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Here is a humble attempt at the physics behind coupling the speakers to the floor.

Air has mass and therefore when the speaker cone pushes against it the air pushes back. Newton explained it this way: For each force applied to an object an equal and opposite force is applied.

The cone applies force to the air molecules and the air molecules apply and equal force in the reverse direction. Now its true that the combined mass of the speaker and the box it is housed in is much greater than the air so the speaker remains in place. Ok so far. Well in theory the speaker may move a little in response the opposing force of the air. Especially if the speaker box is sitting on a rug. You can apply force with your hand (large mass) to the speaker and push it along the surface of the rug with ease. It would be of course be a very small a movement when the force is applied by the air (small mass). So small is the movement, it would be difficult to measure. However the movement of the speaker box small as it is would be subtracted from the extension of the speaker come.

So.... if the speaker box is anchored to the floor by its own mass pushing 3 or 4 pointed spikes through the rug and into the wooden floor it would even resist moving if you applied force with your hand. Now when the speaker cone is moving against the air there can be no cone extension loss due to speaker box movement.

That's the best I can do toward explaining. Others can take it from here.

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Correct..

If the speaker box remains in place, then the speaker cone housed in it also remains motionless .

The speaker cone moving against the air, can therefore move more air molecules. This results in a sound wave more consistent in magnitude and frequency to the electrical signal sent to the speaker by the amplifier. Energy loss by way of kinetic energy applied to the speaker box is eliminated.

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I just realized that there is an explanation about how conepoints improve speakers in my Brass Footers owners manual. Here is the text verbatim.

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Conepoints Improve Speakers

Nothing hurts the sound of a speaker more than mounting it unrigidly on a carpet, on rubber feet, on damping pads, on flimsy stands or on shaky shelves. Flexible mounting less the speaker rock back as the cone moves forward. That means boomy bass with weakened attack and dynamic punch. Similarly, freely vibrating speaker enclosure panels muddy the midrange and treble.

To make a speaker sound its best you must stop it from rocking and you must drain panel vibration efficiently. The requires coupling the speaker, via massive brass footers, directly to the floor or directly to an ultra-ridged stand. You can't get good sound just by placing the speaker's flat bottom on the floor or on a stand. because of the large area, low-pressure contact, must of the cabinet's vibrational energy is reflected back instead of being drained efficiently and cleanly down into the floor.

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Depends... what's under the carpet? If wood, then yes, sharp carpet piercing spikes would be good, if cement, then you would have to go a similar approach to mine.

Coupling a speaker to cement would be bad. Cement is a bass killer.

No Disc

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On 3/14/2005 7:47:10 PM m00n wrote:

I have carpet so spikes would be my best bet then, as I understand it.

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NoDisc, I'm confused now. If I understand the above, the goal is to lock the speaker to the flooring, so how would spikes thhrough carpet onto cement floor below be bad? Not flaming, just curious. It would seem to me the connection would be better. Is is a matter of cement being so hard it resonates vibration back into speaker?

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