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Sand and Spikes


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5 replies to this topic

#1 of 6 OFFLINE   Ryan_Papineau

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Posted August 03 2006 - 06:35 AM

No I'm not talking about beach volleyball. A couple questions that seem somewhat related. I've read of some people using spikes on the bottoms of their speakers. What exactly does this do...it seems bass related but I'm not sure what it does. The other question is about the front stages(I assume) that some people use for their home theatres and putting sand in them. Is this another bass improvement trick? My front speakers are B & W CDM 9NTs and I'm just currently starting to do the research into making my own home theatre in the basement and wonder if these are things I should consider for mine.

#2 of 6 OFFLINE   Seth=L

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Posted August 03 2006 - 07:36 AM

placing spikes on certain floor standing speakers is supposed to tighten up the bass. I did this to my PSB Century 600i's and I noticed significantly less boom and more accurate bass reproduction. I do not understand what you mean by front stages. The only time I have noticed sand being used was to fill a speaker stand that was so equipped to decrease resonance and increase stabiliby and bass accuracy. Being that the CDM 9HT's are floor standing I do not understand the question. Seth=L

#3 of 6 OFFLINE   Ryan_Papineau

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Posted August 03 2006 - 08:02 AM

Well to tell the honest truth maybe I'm just wrong on the stage. I'm speaking in reference to the raised area that some people put at the front of their rooms(usually when using a projector). The front speakers then usually sit on that from the pictures I've seen. I'd have to look around but I'm pretty sure I've heard sand mentioned but perhaps I misunderstood. Regardless I guess from you explanation that if sand was used it was to cut down on resonance/increase stability.

#4 of 6 OFFLINE   Bob McElfresh

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Posted August 03 2006 - 04:52 PM

Hi Ryan.

Ok, you need to understand something. There are a lot of tweeks/techniques you can use for a MUSIC system to try to create totally accurate musical reproduction. (Accuracy is the goal of a music system).

But many of these tweeks dont work for a HT system. This is because:

- Home theater sound is highly compressed (6-to-1) compared to an audio CD
- Home theater sound is highly artificial (much of it is added in as background sounds in a studio)
- With home theater the primary focus is the video and audio, but with music it is 100% audio. People notice slight nuances in a music system that they would never notice with a movie soundtrack.
- Humans will sometimes listen to the same CD several times a day/week, but they dont usually listen to a movie soundtrack as frequently.

Dont get me wrong. Many music concepts DO apply to your HT speakers like proper placement, level-adjusting, proper subwoofer placement, etc. But a HT system is not nearly as ... 'sensitive' to things like spikes or sand.

Does this make sense?


In general, spikes are used on the bottom of a speaker to isolate it from the floor and let the speaker cabinent resonate. (A suprising amount of sound comes out of the sides and rear of your speakers). Sand in the speaker stands is to help create a solid footing and keep the pipe from ringing.

Both of these issues are for a Music system played at high volume. (Many people want it to sound good in the next room or throughout the house). A HT system has an array of 5 speakers surrounding 1-3 primary seats. The speakers tend to not be driven as loud so the vibration issues tend to not exist.

Some other Music myths you might want to stear away from:

- You need 200 watts per channel. No, a circle of speakers with a HT sound-track does a great job with a 80 watt per channel receiver.

- You need full-range speakers all around. No, you DO want identical speakers all around, but the easier to adjust/better sounding systems separate the BASS by using a self-powered subwoofer in a premium position. The 5 speakers can all be 'monitor style' and these are placed in the best position for the primary seat. The only thing you really get with tower speakers are the built-in stands (but at the cost of 50% more than the same drivers/crossover in a smaller cabinent).

- You need high-quality, 12 ga wires all around. Well.... I suggest you buy good quality 12 ga like the "Sound King" or Carol brand from www.partsexpress.com, but you just dont notice any difference spending 10x more for high-end retail copper for a HT system. About $0.50/ft is a decent price.

- You need to put 'Vibra Pods' and ceramic disks under all your electronics to improve the sound. No. Having a good rack with lots of air-flow to keep the electronics cool. But exotic 'feet' under your VCR/CATV box wont really do anything.

- You need a power-conditioner to clean up the dirty AC power for your sensitive electronics. Well... if you live in the burbs, your AC power in the evening is usually decent. If you live in the inner-city and your AC power is on the same wires with the gas-station on the corner, the pizza resturant and 20+ neighbors in the building, a power-conditioner CAN clean things up. My advice is to find a store that sells these things and has a 30 return policy. Buy the unit and try your own A/B comparison with the Video equipment to see if it makes a difference. Then return the unit if your spouse does not notice a difference. (Spouses are usually not emotionally invested in tweeks so they are less biased).

There are more myths, but these might be ones you were curious about. Ask about others and we will try to give you honest, although conservitive, answers.

#5 of 6 OFFLINE   McCall

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Posted August 06 2006 - 07:32 AM

You are absolutely correct. People building dedicated home theaters often use sand filling the front stage, the area where the screen, front speakers, center speakers and often sub woofer are for the reason you mention. Others use packed fiberglass.

#6 of 6 OFFLINE   Mark R O

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Posted August 23 2006 - 10:25 PM

Sand is occasionally used as ballast inside the loudspeaker cabinet itself. Lead shot is often used as well. In some speakers this idea is part of the design. The Monitor Audio Silver series are great examples. The Silver 5i had a plug on the back that provided access to the cabinet interior. The Silver 9i used a screw on plate. I have a pair of 5i's with about 70 lbs. of shot in each cabinet. The improvement is anything but subtle. A comment on conditioners. Many are glorified surge protectors. That said, many serious, thoughtful designs are out there too. Even if "the burbs" has a decent power grid (unlikely), your house very well may not. Bob's advice is solid, audition a couple. You may find electrical issues you didn't know you had.
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