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How far must the K33 be sealed?


KT88

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Let's put it this way:

Would you buy a speaker that you knew ahead of time that it leaked air or a pair that you knew ahead of time didn't? The R. Small quote indicates that even a gasket leak is measurable.

I'd want the pair that didn't leak. So the answer is YES, if you have older speakers and a question about the quality of the gasket seal in your speakers, open them up and check it!

WARNING: Snide comment follows...

However, if you are listening to crossovers that are over 20 years old, WHY BOTHER?!

DM

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I agree with John too. I would'nt want a single air leak in a sealed chamber if I could hear the difference or not. Sealed is sealed, NOT kind of sealed. Just pump a little Silicone sealant in the void, lick your finger, wipe it clean, let it dry and be done with it. It'll take all of about 2 minutes. And afterall, piece of mind is what you are looking for, is'nt it? [;)]

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I guess I agree and disagree at the same time. Can I do that? [:D]

I agree with everyone's position that it should be sealed, and it is either completely sealed or it is not (which is not good). Period.

But, looking at both pictures Bob posted, all the old ones definitely leak by design, and even the new gasket does not appear to be of the integrity that it seals "hermetically" or completely. It is just a cardboard spacer that looks more like a vibration absorbing material than an air leak preventative.

If it was so crucial, that gasket could have much higher integrity, and a better material type, like rubber, especially around the screw holes. Klipsch used rubber gaskets on their access doors, but cardboard spacers on the woofers.

Think of the oil pan or transmission pan on your car. Those are gsakets, and made not to leak.

So in the end, yes, take extra care when you install a new woofer, but don't be fooled that some miniscule amount of air isn't getting past that cardboard seal and other parts of the woofer.

And I still can't believe that any of us could hear the difference between the 2 woofer seals Bob has posted. Does anyone think they could?

Other than that, we agree.[:D]

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I don't know if we can hear that lack of seal in the gasket or not. I do believe though, that I could measure it with doing T/S testing in a sealed enclosure. I will, in any case, plug up the hole in the gasket on this one before I put it back in a speaker.

Bob Crites

post-9312-13819300643648_thumb.jpg

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Fine then, don't take "my" word for it...

"Leakage losses are the most significant, giving Ql values of

between 5 and 20. The last result is surpising, because the enclosure tested

were well built and appeared to be quite leak-free. In fact,

some of the more serious leaks were traced to the drivers.

These leaks were caused by imperfect gasket seals and/or by

leakage of air through a porous dustcap and past the voice

coil."

Small, R. H., "Vented-Box Loudspeaker Systems Part I:

Small-Signal Analaysis," J. Audio Eng. Soc., 1973 June.

Not trying to argue, but there are many times where increasing the Ql is beneficial. This notion that "not sealed" as a negative attribute seems to me as a bit misguided. There are tolerances built into every design and "compromises" are constantly being shuffled back and forth. Choosing the Ql of the cabinet is just one of many variables that can be adjusted to improve performance.

I think the reason Klipsch moved to the newer gasket material is due to the fact that their drivers are all OEM and it's probably much easier/faster for Eminence to manufacturer a gasket that "locks." Ever try reconing a speaker with the old style gaskets? It's much more difficult to get it all lined up versus the newer notched versions.

But I'm surrounded by Klipsch engineers right now, so why don't I just ask them and see what they say? [;)]

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A proper seal is critical to achieving the modeled performance. I can't believe this actually deteriorated into a debate. Those four slots add up to be a good sized hole, so this is more than just "minor" leakage. It seems silly to me to pull the drivers out, see the problem, be concerned enough to ask about it -- and then do nothing. The drivers are out, the gaps shouldn't be there -- fix it!

You use wood screws because you're screwing into wood?:) Four may not be as many as we want, but it doesn't help matters if we don't make things as right as we can make them.

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Just so everyone knows, I certainly wasn't trying to start an arguement or anything like that.

Obviously it would be a good thing to ensure the best possible seal. I guess if I only had 1 pair of speakers I might have inspected and sealed them up just for the heck of it, because my speakers are all old.

But....since I have several pair of old Heritage it's like "Do I REALLY need to go and do this"?

It would be cool if Bob or someone could present some information from a practical test that specifies how much leakage is "excessive" or "significant", and how little doesn't matter, or if any tiny leak can be measured and makes a difference.

It would just be nice to know the true impact of a small amount of leakage.

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Hello,

It is very important that boitié of the woofer is tight!

For an assembly in low reflex camera to a certain extent it is less important.

if you want that your enclosures sounds the best it is necessary to return seals has the 100% woofer. Not to forget that the escapes of air are audible!

My Scala were re-examined and sounds really well.

It is not difficult A to make silicone and especially to make the assembly of the woofer with 8 screws.

Cordially. From Belgium

Pierre

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