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Topic: home stereo sub woofer |
Jon Light (deceased)
From:
Saugerties, NY
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Posted 11 Aug 2021 7:48 am |
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I'm not an audiophile and don't care to be. But I just bought a new receiver & active sub for my 'home theater' system. Not a big deal. Just upgrading from some 40 year old components.
This is the passive sub I was running. It worked! I thought it sounded ok!
Now...how can it even sound like anything? In case you can't make out what I'm showing, there is no -- zero -- surround left on this down-firing 12 incher.
Why does it work? How is this possible? What is reality?
I am expecting delivery today on the new components and maybe I will plug them in and realize that what I thought was ok was actually awful. Or maybe not?
Clearly, I do not understand how a speaker physically works.
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Joe Hensley
From:
Boise, Idaho, USA
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Posted 11 Aug 2021 8:02 am
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| Basically it is still moving air, creating the sound waves, regardless of the surround. Imagine hitting a sheet of metal, it moves the air and makes a 'thunder' sound without a surround or voice coil, etc... |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 11 Aug 2021 8:07 am
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Would I assume that with a proper surround, it would move air at 20W that it now takes 80W to generate?
Something like that? |
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Joe Hensley
From:
Boise, Idaho, USA
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Posted 11 Aug 2021 8:18 am
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Oh, I don't know all the math & physics behind it, but I do know that enclosures are generally built specifically for a speaker's optimal air volume & other things like being sealed, ported, or isobaric. By losing the surround, there's no longer that 'seal' to ensure the enclosure is doing its job to the best of its ability along with the speaker.
I'm sure you'll notice a difference with your new setup. |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 11 Aug 2021 8:47 am
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| Thanks. Nah -- I'm just throwing numbers around. I assume that efficiency is the first casualty of this. I just wouldn't have expected this to work well enough that I never felt compelled to inspect it to see why it was rattling or fluttering or something. No symptoms of any issues. To my non-audiophile ears, at least. |
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Larry Dering
From:
Missouri, USA
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Posted 11 Aug 2021 9:07 am
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| Jon, that's amazing. I can't see how it would have stayed functional without blowing the voice coil. Almost like a car suspension without springs or shocks. |
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Joe Hensley
From:
Boise, Idaho, USA
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Posted 11 Aug 2021 9:08 am
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| All good friend! I still get amazed at the sounds that can come from a groved piece of vinyl, a magnetic tape, or a bunch of 1's & 0's. |
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Jerry Overstreet
From:
Louisville Ky
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Posted 11 Aug 2021 9:19 am
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I guess the voice coil is still centered so there's no rattling or rubbing. Bet it would if you crank it though.
Cool old CV driver though and you can get a DIY kit to replace the surround and it'll probably be good for another 20 yrs. at least. Those old school units are hard to beat. |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 11 Aug 2021 9:21 am
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| I only pulled it out of storage and set it up a few months ago. The cat kept reaching under and pulling out bits of red paper. I knew something was....not right. But it was working so all's good, right? Anyway, new stuff coming in later today. Then I'll go out and check my shocks. |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 11 Aug 2021 9:26 am
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| Jerry Overstreet wrote: |
Cool old CV driver though and you can get a DIY kit to replace the surround and it'll probably be good for another 20 yrs. at least. Those old school units are hard to beat. |
I am definitely thinking of doing that. Don't have much use for this big honking unit though. |
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Marty Nemanick
From:
Madera, California, USA
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Posted 12 Aug 2021 8:55 am
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| The DIY foam surround kits are very easy to install, I've done a few of them and this speaker would certainly be worthwhile giving it some new life! |
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George Biner
From:
Los Angeles, CA
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Posted 12 Aug 2021 10:21 am
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The higher frequencies will be driven by the paper cone which is still moving back and forth and centered by the spider. For the high frequencies, air is maybe a better surround than foam. But where you'd have difficulties is in the lows because you no longer have a sealed box/port system -- so the port and box, which extend the response at low frequencies, basically now have a huge air leak.
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Electrical engineer / amp tech in West Los Angeles -- I fix Peaveys
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