Are loudspeaker dust caps important?
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- เผยแพร่เมื่อ 11 ก.ย. 2024
- We see dust caps guarding the inner workings of loudspeaker drivers all the time but just how important to the speaker and its sound are they? Have a question you want to ask Paul? www.psaudio.com...
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Dust caps are there so children have something to poke their fingers through, everyone knows that.
😆🤣😆🤣
I thought that's what the tweeter dome is for. 😖 😖 😖
@@terrywho22 Can't leave the short ones out of all the fun.
I did that with a pencil trough a 15" infinity speaker when I was little.
Ok, if we're in confession mode here, I'll be honest...
I totally crayoned the grilles of my dad's AR3ax, thought he was going to kill me.
@@poserwanabe How old were you? I feel your old man's pain.
You know you've been watching Paul too much when you're waiting for him to apologize to Ohm's Law listeners.
"really gets pissed" love it, what a way to describe touching it lol.
Funny dust cap story. My friend dragged over a pair of Event 20 powered studio monitors with poly drivers and caps. Anyway, one was missing a cap (that one sounded fine) and the one WITH a cap was highly distorted (or worse) at any reasonable volume level or higher (okay?? if at low volume). The voice coil measured good, decent match for coil dcR and coil inductance to the "good" one. Also, it didn't rub.
It was a "head scratcher" and maybe a new $$$ speaker to repair.
Last chance for something we might be able to repair.... maybe an intermittant connection from the tinsel to the voice coil that needed to be resoldered. The cap need to be removed to do that.
Discover the "loose" cap in the process.
Weirdness starts here:
It turned out the cap was partially unglued (not obvious) and acting like a check valve. The speaker motion could pump air "out" of the magnet/coil motor thru the unglued part of the cap on the speaker's backstroke... but the cap reseated tightly on the glue line and wouldn't let air back in on the forward stroke. Play it loud and the cone's average position kept moving back until something was hitting (suspect the coil former was hitting the bottom of the magnet annulus.
So... two new matching caps and a tube of glue later.... they were as good as ever.
dennis walsh very similar problem with my 18, there was a small cut in the dust cap and the woofer would make a terrible noise sounded like the whole thing was junk, ended up putting a piece of tape over the cut and sounds perfectly fine now
5:12 I used to pull the main fuses on my stereo when I was out of town so the kids couldn't power up the monster without supervision :)
"dust caps don't affect sound much"
Phase plugs has left the chat.
😂
well thats why i searched for an explaination on that subject. I have some focal 6.5 coax speakers but i removed the tweeters to place them upper on the door. now the speaker is missing its center piece, i know the original component ones have a phase plug on them. so will it really affect sound or dust collection on the vc?
@@fabiuh991 I am not using the tweeter with my coax unit, either, I found it at least important to put a foam bung in the back hole where the tweeter goes. Them I (recently) doped the dust cap and found it improved phase coherence.
In addition, doesn't the dust cap add some rigidity to the speaker cone to aid in mitigating physical distortion of the cone itself?
I love how super expensive home speakers look like cheap car audio subs
I feel that the dust cap provides more surface area on the cone itself and helps with rigidity, increasing overall efficiency
Wow, I'm a bit surprised to hear that having no dust cap doesn't make a whole lot of difference.
Especially in sealed box speakers! Essentially you're making the speaker ported in some sense, when the cap is missing. How can this not affect the sound?
Also in ported speakers, the sound would change if you add another hole to the box.
I guess I'd have to try to find out, I just don't have a speaker lying around right now to try it O:-)
Removing the dust cap can sometimes help in dipole (Open Baffle ) applications : some motor designs have a rattling sound emanating from the rear of the speaker at high excursions (before Xmax) . In a closed box , not a big deal , in an Open Baffle a very big deal . I personally have experienced that the rattling completely dissapeared after dust cap removal on 2 woofers I had installed in a Ripole sub
in some drivers the dust cap could extend the high frequency response of the driver.
Old speakers lacked a dust cap as there was a second spider attached to the voice coil and the magnet which was attached by a screw in the middle.
You forgot an important point. The dust cap reduces clearance volume, forcing air through the voice coil air gap with a good amount of pressure. That's crucial to cooling the voice coil. With out it, the coil cannot handle as much wattage without heating up, causing power compression, noticeable odor, and at worst, SMOKE! The size of the cap, and the chamber volume of it also help dampen the free air resonance of the driver, giving a flatter sound. Not only does the cap act as a diaphragm to force air past the coil, it actually tunes the driver. Removing it can change the Thiel Small parameters of the driver. When replacing it, it's important that the effective chamber volume be as close as possible to the original. It's best if it's non-porous.
Vincent Robinette : ... best if non porous... that’s a big claim, not sure I would agree if I was designing scratch up for low compression/ high dynamics.. ( I don’t disagree) ... it does go against phase plugs and many successful driver designs... ( I’ve never favoured that direction myself though)
@@justinmallaiz4549 That statement is made purely on a power handling standpoint, especially for woofers. Porous is perfectly OK, as long as there is enough air forced past the voice coil, to handle the power. To run with a porous, or even no coil cap reduces the amount of force needed by the coil, to move the cone, thus, produce more sound per watt. If you're doing Hi Fi at low listening level, this is not a concern. If you're running hundreds, or even thousands of watts RMS into high performance subwoofers, then, it's a HUGE concern! Phase cones are particularly effective, if a driver is reproducing frequencies high enough, that the wavelength of sound is shorter than the diameter of the piston of the driver(not counting the surround). At high frequencies, the cone cap becomes a major player in the acoustic character of the driver.
I’m 12 years old and I was into amplifiers and speakers sconce I was like 3 you got me laughing when you said that kids and stereos don’t go well😂😂
Tonight I just rebuilt my old 1991 JBL LX-33 surrounds (successfully swapped the crusty foam surrounds with new rubber ones) and used shims to centre, and was wondering if I can test tomorrow (after T7000 glue fully cures) before I order dust caps... this video answered my concerns, yea!! LOVE you and your channel Paul, such a lovely person, I could listen to you for hours, many thanks.
If the speaker is vented the dust cap is very important as it allows the cone to suck air in through the vent hole and blow it back out to help cool the coil at high volume. With out it the coil will overheat at high volume and damage the coil.
Dust caps are not snake oil. They serve a protective and performance purpose. Less cone area means less SPL and interference patterns at the center of the cone are not good for the audio fidelity.
my 3 year old has pressed the dust cap and broke it on both speakers :(. Will try to replace it, but you are right "Kids and electronics don't get along well :( "
Thank you wery much for your videos 🙏🏻, I just saved a pair of B&W dm601 s3 speakers, got them for free couse my friend wanted to throw them away 😵💫. You just saved them, and they work amazing. Thanks 🙏🏻❤️
Larger dia bass speakers like 15" 18" use an inverted dust cap to give more cone face allowing more air movement but I agree with most midrange/midbass speakers don't actually need the dust cover for performance reasons it's just to keep the dust out
I have to replace some dust caps on a pair of infinity speakers myself. Was impossible to find the exact same geometry cap. I hope things go well while trying to replace them. I have not had much luck refurbishing old speakers... yet. 😐
Woofers pp cones have a bigger dust cap. The cone is very thin ang Light. To work efficiënt. The cap make the cone structure stronger. Airtight caps also push air trough the coil vent holes. Without a dust cap you can hear on some speakers air pussing trough the coil.which distorts the sound.
and the famous aluminium JBL dust cap.... The K110, K120 and K140's had a sound of their own 🎵 Now worth more second-hand than they were new.
fuck me that's a beautiful woofer. these speakers are gonna be gorgeous
I'd love to have this guy as my loudspeaker course professor!
Ehhh there are many speakers that are designed without a dust cap ie Revel for one a very high end manufacture of incredibly good speakers actually some would say the best
I've always wondered why not make the port in the center of the subwoofer making it kinda like a coaxial subwoofer? It would help keep the voice coil cool. The more you turned up the volume. The cooler the subwoofer can be. Until you run out of excursion. Im sure that it can be done with the right design and tuning. I could see it working on a very large subwoofer driver.
Just to confirm, coil travel within magnet is small for higher frequency and longer for lower frequency. So what is the total travel dimension of a woofer ?
It varies, but the biggest SVS does this...78mm peak to peak Xmech excursion (65mm Xmax)
Skip to 5:27 to get the answer you came here for.
Surface area of membrane......?
SO...what about the hard bullet cap on some car audio speakers? My kicker 6" failed with a stuck cone. I managed to get the bullet out and the plastic was melted, binding the cone. Works fine without it now. But I live in a very dusty dirty environment. This driver is actually in a box as a bookshelf speaker. One thing I see is that a bullet inserted into the coil is not acting nearly so much as a dust cap. It's not affecting the cone at all and only keeps out some of the dust since there is a gap (unless it's melted!). I guess I'll just replace the reworked bullet. But this is making me wonder why premium car drivers have these bullets in the first place. Just for looks? Less interference with the cone?
Thank you for the information. The woofer on your desk makes me wonder why modern dustcaps are so much wider than the voicecoils that they cover. Is there a sonic reason?
guy asks about a dustcap and it goes into a long winded spider conversation.
Why do my Monitor Audio towers have no dust caps on the mid & bass drivers?
How to cleaning the speakers?? if my speaker doesn't comes with dust cap,which way do you recommend it without getting harm to speaker?
KEF uni-Q drivers and mid bass/woofers with phase plugs never had dust caps.
I’ve been looking into a DIY speaker kit called the Volt10. It has a soft dust cap you can see through with a tweeter mounted to the back of the woofer magnet. What are your thoughts on this? (As a surround speaker)
You'll love it. It is call a coaxial driver. With the tweeter in the center, your time alignment stays the same for off axis listening. Off to the side, it won't be as loud, but the sound quality is still there. You can't beat it as a side fill in a surround sound system! Just get the crossover frequency right, so the drivers are in phase at the crossover point, and they can perform quite well.
if the speaker cons tear can it cause distortion? my speakers are distorting but the only tears i'm finding are on the cones
120 can one install aftermarket an excellerometer into a sub cabinet? What and how can it be done?
White cones, I could never understand why designers used different colors on their cones. KEF uses blue and orange for example, and they are as ugly as sin. I would think a nice black would be the least intrusive.
The white cone would look better with pink poka-dots on it. But I would like a pink speaker with purple poka-dots!! :)
I believe everything should be made grey, not to offend the colorblind.
@@mankepoot9440 They don't need to be favored. We should not offend them by realizing that they are not below letting us enjoy the freedom God gave us to see colour and enjoy it. :)
One of my center channel woofers dust caps is discolored but doesn't effect the sound
Help to move air which cools the voice coil
How about whizzer cones?
Thanks Paul ole chap. My cat or the cable man put a small hole on one of my woofers on my Infinity 2000.5 killas! Hahahahaha Have a great day my friend
so if you have air coming out where the dust cap is supposed to be what do you do?
I also have a buzzing noise. I figured if I put a dust cap on there and held the air from blowing out of there it would stop.
Some logitech speakers does not have dust cap on. Instead a tweeter is placed over the main coil, like with car speakers
"Like with car speakers"
*Advent leaves the chat*
Dust caps DO change the sound. Remember JBL's (and others), using aluminum ''chrome'' caps?. They were there to increase midrange output, as means of a rigid dome midrange driver would. Some dust caps are very acoustically transparent, to acomodate a coaxial tweeter, try changing that cap, for a paper one!...
This was great. Thank you! Love watching your vids, by the way.
i would have thought the dust cap would add a significant amount of rigidity to the cone and therefore be quite important!?
I added a 5" dustcap to a 8" sub, purely for kicks.. and to my surprise it made for more punch and output. Made the cone seem a lot stiffer, and I can't find one negative effect on sound.
Reasons for a dust cap: Dust, smoke, humidity, bugs, pets, kids.
You forgot 2 reasons: Cooling of the voice coil by forcing air through the gap, and dampening. The pressure created by the piston helps dampen the free air resonance of the speaker. The volume of the chamber created by it is actually tuned!
... even frequency extension... eg : dust cap attached to voice coil former.. sometimes using alluminum or with wizard cone...
If you knew Arnie Nudell personally, why didn't you attempt to make a new accelerometer?
Sounds like the philips motional feedback speakers.
I’m at 2:03. Has he answered the question yet?
What would happen of you put a weight inside the dustcap
Who knows what effect the dust cap has on a speaker .... it will vary a lot from speaker to speaker. Since in the case of those IRS bass speakers the dust cap has been removed there is an air bypass... if that speaker went through a T/S test set and the figure for Vas was derrived then that figure has a lot to do with determining the box volume. Now the dust cap will affect that Vas value .... I don't know if those 6 bass drivers have their own separate divided enclosures or not but if they do then the speaker without the dust cap but with the accelerometer is now working in the wrong size box and is trying to " correct" the responses of the other 5 ... via the servo system ... doesn't sit well with me I gotta say
I just bought a new set of speakers, when the first thing one of my friends did was push the tweeter cone🤬
Big plastic caps help as a piston I like the look too like a big wock
If it is fed a full range signal, the dust cap will affect the sound.
Yup. I remove mine because of dust cap resonance.
If you ever get magnetic particles in your motor they can be neer imposible to remove
How would you remove it and why would you want to?
4:40 did he say schmutz? i dont understood what he said
It's true automotive coaxial speakers will not have dust cap yet they sound great.
thank you sir for clarifying that
Help! I have a dent on my woofer on my wharfadale 9.1 . Do i need to fix it? Will it effekt the sound quality ? The dent is the size of a finger tip.
I wouldn't worry about it.
@@Paulmcgowanpsaudio man i really appreciate the answer!
hey Paul what is the use of a grill on speaker/subwoofer good for?
They are mainly there to prevent damage to the speaker cones and to keep STUPID people from touching the speaker and putting a big dimple in the dust cover. It seems today the trend is to have no cover and it would seem to help the sound somewhat because many cloth grills interfere with the woofers air movement.
I prefer a grill over the speakers anyway because of the risk of damage.
I really don't know how much the grill cloth can affect the woofers, the fact that I can see the cloth move when the woofer is producing strong bass would seem to indicate a possible issue.
So.... Yes or no?
The simple answer is if you run a woofer without a dustcap the woofer will not last long at all
This video doesnt explain anything... Dustcap is to keep the dust out, because speaker will suck it in by the cone movement and the dust will get stuck between magnet and coil and make some scraching sound, worst is when this dust is attrackted by magnet, then ist harder to remove it.
Is that a Wavecor?
"schmuts"?
Spelled how in English?
In Swedish it's smuts but I didn't knew it was used in English =P
Schmutz. That's german for dirt. I'm german and i was suprised hearing that xD
Ah huh, so that's why the dust cap was removed from the IRS bass driver!
The Visaton w130x uses a metal plate as dustscape. This is to create more weight.
At 4:20, nice technique keeps friend happy.
Paul, I’ve noticed last few years many speaker manufactures using what I’d call an inverted dust cap. Iam guessing this is due to the idea dust caps look a bit like giant belly buttons on an otherwise beautiful piece of audio. Is this just cosmetics? I tend to forgo any speaker with an “outie ‘ especially if the drivers are to be exposed.
Matt K : ....for the most part cosmetic.. 🙂 ...
my berylliums and my nice... not mix well ...
My dad used to say "keep your zipper up",
Whatever that means.
Lol
Nice thumbnail
In speakers as with all things electrical always wear protection.
Damn kids...
^^^^Best Woofer Ever Made^^^^ Right There Folks! Just "Ask Paul".
You know the brand? I´ve seen this design somewhere before, but I can´t remember what it was.
I love how he refers to it as a monster , clearly never seen a competition SPL woofer.
chris vinicombe ~ like a 25 inch 5.5Kw job
Wow ask a simple question and hear everything that's irreverent and bloated. Yes or No would have been sufficient. Simply put does not having a dust cover effect the sound quality of the speaker. Oh sorry at the end of the video we came to a conclusion. Great thanks
Schmutz =)))) heheheh