And this experience comes from?
Please I asked this of Dr. Geddes.
Now if you want to comment on the following go for it... 🙂
I throw out many suppositions from time to time, often times already knowing the answer and have been beat down with illogical conclusions based on Joe down the street. Honestly I have no time for it and 99% of the time it is not me that's incorrect and is critical or important to note. These simple leaks can cause great harm to the intended result depending on design. AS speakers should not be leaky. The slow build up or decrease in pressure normalizes due to a leak, but not a pinhole. Think more along the lines of a gas permeable membrane. It is slow and gradual. Atmospheric pressure builds and recedes slowly under normal conditions. It's not like we're going from sea level to 10k feet in altitude in a matter of minutes, or a concern when a tornado passes through the neighborhood. Even hurricanes pressure drop is of no concern. It simply doesn't occur fast enough.
Please I asked this of Dr. Geddes.
Now if you want to comment on the following go for it... 🙂
I throw out many suppositions from time to time, often times already knowing the answer and have been beat down with illogical conclusions based on Joe down the street. Honestly I have no time for it and 99% of the time it is not me that's incorrect and is critical or important to note. These simple leaks can cause great harm to the intended result depending on design. AS speakers should not be leaky. The slow build up or decrease in pressure normalizes due to a leak, but not a pinhole. Think more along the lines of a gas permeable membrane. It is slow and gradual. Atmospheric pressure builds and recedes slowly under normal conditions. It's not like we're going from sea level to 10k feet in altitude in a matter of minutes, or a concern when a tornado passes through the neighborhood. Even hurricanes pressure drop is of no concern. It simply doesn't occur fast enough.
Even if the pressure equalizes in seconds its still insignificant in the audio range.
Yes, I have modeled this. Unless the "port" (or "pinhole") has a mass such that this "port" and the box volume resonance is up above about 1/2 of the in box resonance of the driver, Fs, the effect is negligible. Small holes have huge acoustic mass because of the square of the area in the denominator. It takes about a 1/4" hole in a small box to get to this. And remember that small holes become highly resistive so the "leak" is not as big a deal because it is not out of phase with the radiation.
Biggest issue with a small hole is a whistle (been there).
🙄
Yeah, I tested it with Hand Clapping recordings and there was not an effect
😀
A pinhole won't have any effect on the operation of the box within a periodic range. While the size makes the prediction of the operation of it a little finnicky, it's like a pinhole sized port. What frequency would a .025" x 1" vented box operate at?
Yep, whether the enclosure is tiny or huge, <.5Hz. I've built my share of boxes, and the volume of the box and effect upon enclosure operation is not meaningfully affected by miniscule leaks.
If you've got some feedback that's not useless I'd welcome it. Perhaps you have an example you'd like to share rather than talking about how great and experienced you are?
which is highly pressure dependent. I've not found it to be an issue in any of my boxes- though I could see it as a challenge in something like an eq'd sub at high displacement.
What circumstances have you encountered this during? What kind of enclosure, where and how big was the hole, etc?
Your 801's may be ported, mine are not. As a source of fatigue I would guess barometric pressure has more of an effect on the listener than on the speaker.
I fully agree, David. I've never liked FM very much. IIRC from my radio frequency engineering days, AM is a very tidy system where the broadcast bandwidth is exactly twice the frequency response of the input signal. It really can be as good as you want in terms of quality, and American stations often allowed a frequency response up to 15 kHz.
Sadly to cram more stations into the spectrum, the frequency response of most transmitters was limited to about 5kHz. That's almost telephone quality. 😡
FM (no static at all....😀) is much more demanding of bandwidth, and a fast rising signal is almost unlimited in its spectrum demands, a Bessel response IIRC. The practical result is the signals are severely constrained in rise time when you try to cram lots into a band. We would call that slew rate limiting in an amplifier, and it sounds HORRIBLE! 🙄
Just putting a plug in for Visaton TW 70 cone tweeters here, since NOBODY is interested. But here's why they sound unfatigueing:
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Robin Marshall: A Modicum of Genius Page 4 | Stereophile.com
No man, its fight or fight (-:
This is The Mississippi Swamp
We have big trucks in our garages, big speakers in our living rooms, deer heads on our walls and guess what? "Honey" *still* brings us a beer now and then. The concept of a "man cave" makes us feel bad for ya'll. Guys getting pushed into the garage with your big TVs and stereos by your own women and then you let them disparagingly call it a "man cave" (-: No men in them caves.
To us, a "man cave" is a little pocket under the water where the gators stash the remains of those of us who took "flight" instead of fight'n Here in the south Mississippi/South Louisiana swamp, last bastion of manhood, all of us diverse mixed mutts know It's still *fight or fight*
Yeah, you are right it is testosterone paradise.
Proud?
Damn right we are!
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LOL I live in Biloxi for a while when in tech school USAF. Not the same place today as it was some 30 years ago (is Fiesta Fiesta still there?), long before the casinos infiltrated the coast. Never saw so many people everyday lookin for mudbugs. Do you suck the head? 😀
Earl, these are ported speakers, your speakers are designed "correctly". All ported speakers exhibit what I was speaking of to some degree depending on suspension. The B&W 801 series 3 and many more like it are particularly offensive. It's just a bad idea, another bad compromise.
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Read "Mississippi Mud" one of the best real crime books ever. I can attest that that book is 100% accurate. I was there I was involved with all of those people but I never let them suck me into the dark side. I can tell you "the rest of the story" but damn sure not here. Come visit, bring me some work, oh I guarantee you will get your moneys worth on this story, some things that will make your jaw fall off, even before we look at yout project. Ps playing crawfish boil at a Casino dead on the site of Maladnitches old Fiesta tomorrow! but you can have those ditch roaches. Yuckk.
hes
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Reality check for the no bullschitt inclined. Small leaked in speaker like EGs and Heresies are not acoustally significant and they are needed.
I don't have a strong view about ported versus closed box, beyond the observation that they sound wildly different and are DIFFERENT solutions! 😀
You choose your poison. Reflex has a smoother sound in general, but actually is inaccurate in time response and tends to distort more due to larger cone excursion. Closed box is much more demanding of good cabinet design but can slam in a good and lively way.
Like the classic Gale GS401A speaker, that would sure wake up the neighbours down in the swamp:
I'd lose the Celestion HF2000 dome though. LOL
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You choose your poison. Reflex has a smoother sound in general, but actually is inaccurate in time response and tends to distort more due to larger cone excursion. Closed box is much more demanding of good cabinet design but can slam in a good and lively way.
Like the classic Gale GS401A speaker, that would sure wake up the neighbours down in the swamp:
An externally hosted image should be here but it was not working when we last tested it.
I'd lose the Celestion HF2000 dome though. LOL
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I grew up in West Germany where due to some post-war allied regulations almost all radio stations were FM. I've never noticed any audible problems with FM except that sometimes the 19kHz carrier tone was audible. Very much unlike AM where I have never heard anything which even remotely resembled HiFi.
If I remember right in Stuttgart a good tuner could receive different 28 FM stations in glorious stereo and without undue noise.
You guys didn't have to live across I75 from Fuzzbuster. Back in '79 they ran tests (one of my fathers HS classmates owned FB) that would scramble everything like a massive continuous solar flare, or an EWO gone crazy! Hated it then, Laugh about it today (especially after being in ECM 😉
The McCarthy audio BS Filter:
A. Do you or any publication that you are involved in do cable reviews other than on mechanical and LCR merit?
B. Do you or any publication that you are involved in refuse to do cable reviews other than on mechanical and LCR merit?
If you answered *no* to A your thoughts have validity and are worthy of reading.
If you answered *yes* to B your thoughts have validity and are worthy of reading.
If you answered *yes* to A, have a nice day.
A. Do you or any publication that you are involved in do cable reviews other than on mechanical and LCR merit?
B. Do you or any publication that you are involved in refuse to do cable reviews other than on mechanical and LCR merit?
If you answered *no* to A your thoughts have validity and are worthy of reading.
If you answered *yes* to B your thoughts have validity and are worthy of reading.
If you answered *yes* to A, have a nice day.
Hmm, what I notice about our horribly compressed FM stations in the UK is that my own CDs sound way better than anything broadcast on FM. Perhaps my aerial is no good, it is, after all, the usual internal dipole rather than a roof mounted jobbie.
But even when I had a PROPER 7 element roof aerial, it was never that good. Low hiss, but lacking something in terms of clarity. 😕
I do know the BBC used a 15kHz 14 bit PCM system to distribute live broadcasts, so that was a bit of a constraint.
What is fuzzbuster and 175? I'm lost. 😀
Big reflex with tight susension seems to be fine. Ala Cornwall and big Altecs etc.
Big tip to speaker maker guys. Pretend you are PWK and you are at your prime. Design the prime 3 way speakers again using the knowledge tools and drivers we have now. Send me a check for lighting a fire under your acss. (-,
Big tip to speaker maker guys. Pretend you are PWK and you are at your prime. Design the prime 3 way speakers again using the knowledge tools and drivers we have now. Send me a check for lighting a fire under your acss. (-,
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Could be multipath causing issue.
Fuzzbuster was the first company to produce police radar detectors. I-75 is a main interstate artery through the US from Sault Ste Marie MI. to Miami Florida. It follows an ancient indian trail home of the mound builders, believed to be related to the Anastasi indians. The county I grew up in was Miami county Ohio.