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simmel
02-15-2009, 12:24 AM
I don't know if this topic has been covered in the forum before or not, but here goes.

Over the years I have had my speakers performing with the so called dust covers both on and off. Just recently I took the covers off on my Sonus Fabers for the first time in about a year, and experienced a completely different sound. The mid range and sound staging seemed much more open, and the base was not as warm as it had been.
I had not moved the speakers and they were playing though the same amp as usual. I'm not too sure if this was the sound I liked or not. I must admit I liked the nice warm sound, but the not overly bright mid range did sound good as well.
So what's your opinion?

theaudiohobby
02-15-2009, 01:59 AM
Having covers on or off is very much dependent on the speaker design in question, my current Tannoys seem to prefer covers on (which is good for me), whereas I seem to recall that the small ELAC 310 prefer cover's off. I had Sonus Faber Concerto Homes once, but I can't remember whether they sounded better with grills on or off. :2:

emesbee
02-15-2009, 03:40 AM
I have a new pair of VAF DC-Xs (local Australian brand, check their website if you like, www.vaf.com.au. I've tried them with the covers on and off. Can't really say that I've noticed any noticeable difference in the sound, but I prefer to leave the covers on.

Kevio
02-15-2009, 06:46 AM
Speaker manufacturers try to design their covers to be acoustically transparent. If you're hearing a difference, they either failed at that or you're fooling yourself. Have a friend blindfold you and choose a cover configuration. See if you can tell the difference in a blind test. Let us know what you find.

Ajani
02-15-2009, 07:35 AM
Speaker manufacturers try to design their covers to be acoustically transparent. If you're hearing a difference, they either failed at that or you're fooling yourself. Have a friend blindfold you and choose a cover configuration. See if you can tell the difference in a blind test. Let us know what you find.

I disagree.... Covers on or off can make a big difference... only some manufacturers design the covers to be acoustically transparent...

Some manufacturers, such as Paradigm, design their speakers to be used with the covers on... and the difference in performance can actually be measured (check Stereophile's review of the Paradigm Studio 20 V4 for example)...

02audionoob
02-15-2009, 07:56 AM
The covers on my primary speakers are perforated metal with fairly large holes. The sound seems the same with the covers on or off. However, for the bedroom stereo and the home theater setup I have speakers with cloth covers and there's no doubt in my mind they sound clearer with the covers off. I keep them on, though...don't like the looks with the covers off.

Kevio
02-15-2009, 09:20 AM
Some manufacturers, such as Paradigm, design their speakers to be used with the covers on... and the difference in performance can actually be measured (check Stereophile's review of the Paradigm Studio 20 V4 for example)...OK, looks like transparency is not the only design approach. Sounds a little suspicious though. Along the lines of improving NS-10's by hanging tissue in front of the tweeters.

02audionoob
02-15-2009, 10:26 AM
OK, looks like transparency is not the only design approach. Sounds a little suspicious though. Along the lines of improving NS-10's by hanging tissue in front of the tweeters.
I've actually done a similar thing with my Focal speakers on occasion...depending on the music being played. Not tissue, but a cloth. It can be less fatiguing.

Edit: I've done a little reading on the NS-10 tissue thing. I see now it's a bit different than what my cloth is doing. The tissue is apparently reflecting highs back into the tweeter. I think my cloth (linen) is probably mostly absorbing rather than reflecting.

theaudiohobby
02-15-2009, 11:00 AM
OK, looks like transparency is not the only design approach.

Some manufacturer use grills to tune the FR, Here is the Dynaudio Sapphire, here the grill cover is specifically designed to modify the speaker lower treble behaviour.
http://stereophile.com/images/archivesart/109Dysfig6.jpg

Auricauricle
02-15-2009, 11:26 AM
I think that listening to music is about psychology as it is about physiology. Saying that, I have no doubt that certain "expectancy" effects, much like placebos, crop up now and then, when we expect a certain sonic characteristic to be produced in a given situation. For example, I sometimes think that I perceive locations of instruments, vocalists, etc., with the grills removed. At the same time, I realise that I am more congnizant of the speaker's location and their directionality, for they have been made visible. So, is there a difference, or am I just psyching myself up to perceive it? I agree with the comment that grills ought to be sonically transparent, but this may be naiive, as I am sure that some manufacturers design their speakers with the grill as in important and integral part of the architecture....

Food for thought.

IBSTORMIN
02-15-2009, 11:32 AM
I believe the speakers are designed with the cover in consideration. My speakers sound warmer with the covers on, more bright and open with the covers off. The brightness with the covers off wears you out listening to them for extended periods.

Auricauricle
02-15-2009, 11:39 AM
Well, there ya go, then! Mebbe we should design covers for the ears for that very reason!

Kevio
02-15-2009, 04:02 PM
:lol:

Pat D
02-15-2009, 04:30 PM
I disagree.... Covers on or off can make a big difference... only some manufacturers design the covers to be acoustically transparent...

Some manufacturers, such as Paradigm, design their speakers to be used with the covers on... and the difference in performance can actually be measured (check Stereophile's review of the Paradigm Studio 20 V4 for example)...

I think the grille assembly for Paradigms and some others (PSB) is designed to cut down diffraction effects from the edges of the speaker cabinets, and this smooths the frequency response and helps even out the dispersion. My Paradigms and my older PSBs certainly sound better to me with the grilles on, and the reason is easy to find.

http://stereophile.com/standloudspeakers/705paradigm/index3.html

See fig. 5.

http://stereophile.com/standloudspeakers/629/index4.html

See fig. 4

In other words, if you put a grille on for aesthetic and protective reasons, you may as well make it so that it improves the sound. Makes sense to me.

Kevio
02-15-2009, 06:43 PM
I may be misreading these but it looks to me like you've got the same 5 dB magnitude of squiggles in the high end with and without the grills. Clearly there's a difference in location of peaks and valleys but I don't think you could predict which would sound better based only on these measurements.

But, I agree the designers would have probably (hopefully?) done their critical listening and final design tweaks with grills on so that's probably the way you want to listen if you want to hear what the manufacturer was shooting for.

simmel
02-16-2009, 12:25 AM
I think that listening to music is about psychology as it is about physiology. Saying that, I have no doubt that certain "expectancy" effects, much like placebos, crop up now and then, when we expect a certain sonic characteristic to be produced in a given situation. For example, I sometimes think that I perceive locations of instruments, vocalists, etc., with the grills removed. At the same time, I realise that I am more congnizant of the speaker's location and their directionality, for they have been made visible. So, is there a difference, or am I just psyching myself up to perceive it? I agree with the comment that grills ought to be sonically transparent, but this may be naiive, as I am sure that some manufacturers design their speakers with the grill as in important and integral part of the architecture....

Food for thought.


Some of this reply I agree with, however my Sonus Fabers have a beautiful leather cover surrounding the bass and tweeters, so why cover that up with the grill?
Also if the manufacture intends the grills to be an integral part of the speaker, why make them so easy to detach, why not fix them with screws from the inside for instance. I refer for instance to the B and W who's speakers have magnetically detachable grills to make them easy to detach quote.

hermanv
02-16-2009, 12:59 AM
Commercial acoustic cloth attenuates tweeter frequencies, many speakers come with a tweeter level adjustment which should be adjusted up if covers are added and down if they are removed

Even when adjusted carefully some of the character of the speaker will change since cover attenuation is not flat with frequency.

Most speakers will sound more detailed with the covers removed, often this is a false improvement because it overemphasizes the highs. For many of us, this will lead to listener fatigue.

GMichael
02-16-2009, 09:50 AM
Kids in the house = covers on.
No kids = covers off.

Auricauricle
02-16-2009, 11:07 AM
Yeah, GM, I bet you're a "covers off" kinda guy, eh?

GMichael
02-16-2009, 11:36 AM
Until this summer, yeah.

E-Stat
02-16-2009, 03:38 PM
So what's your opinion?
I agree with Hobby that it is speaker dependent.

The 'stats use stretched spandex, so as Kevio suggests, their affect is nil. This I determined with my previous stats which originally used a thicker weave cloth that did attenuate the highs. I later had a seamstress make some similar spandex socks which were acoustically transparent. In the HT system, I find the Polks are a bit bright, so I prefer leaving the grilles on (along with a 2 db treble cut). With the vintage double New Advents, I split the difference after much experimentation with not only grill position, but tweeter level. The grilles definitely make a difference and I prefer running the lowers on and the uppers naked. With them, it also opens up the soundstage a bit as well. I run the lowers on attenuate and the uppers on normal.

While I am largely an audiophile minimalist, I prefer having tweeter level controls on speakers. I find that speakers that are flat in an anechoic environment to be intolerably bright.

rw

Auricauricle
02-16-2009, 03:43 PM
I notice that my socks are not so accoustically transparent; my wife still hears me when I sneak into the kitchen in the middle of the night....So, spandex, eh?

E-Stat
02-16-2009, 04:32 PM
I notice that my socks are not so accoustically transparent; my wife still hears me when I sneak into the kitchen in the middle of the night....So, spandex, eh?
That's the ticket! :)

rw

emaidel
02-17-2009, 05:19 AM
It's interesting to recall the evolution of grille cloths on loudspeakers in this industry. (I'm curious as to when "grille cloth" was replaced with "dust cover" - perhaps someone can enlighten me.)

In the mid 60's, when AR, KLH and EMI were the predominant loudspeaker brands, no grilles were removable, and in order to repair a defective driver, the entire loudspeaker had to be shipped back to the manufacturer as the grille was thoroughly destroyed by removing it. Removable grilles began to make their appearance in the late 60's, notiably on KLH models, not for the sake of listening to the speaker without the grilles in place, but to expedite repairs.

Eventually, removable grilles became standard on almost all loudspeakers, and retailers would often display the speakers without the grilles, simply to show off what was inside. It was a very common sight to see the dust cap in the middle of all the woofers and midrange drivers to be pushed in by inquisitive consumers.

Foam grilles gained prominence with the introduction of JBL's famous L-100 loudspeaker. No one knew that "foam rot" would eventually set in and destroy the grille, but foam was the most acoustically transparent material available at the time (early to mid 70's), and very well may still be.

I can't say which loudspeaker manufacturer designed their loudspeakers to be listened to with, or without the grilles, but I would suspect most would have designed the units to be operated with the grilles in place, simply because that's how most people would be using them. Certainly with the Dahlquist DQ-10, the speaker was to be listened to with the grille in place, because the speaker looks downright awful without it!

Lastly, let us not forget what some Japanese manufacturers brought to the scene: huge, expensive looking, plastic trim rings surrounding junk drivers to try to make them look like they were actually decent. I seriously doubt that fooled anyone who reads this forum, but it sure sold a ton of stuff!

Today, it's probably a matter of user preference. Whether the manufacturer designed the speaker with the grille in place or not, the user himself will decide which way he prefers it, and, as long as his wife can stand the looks of the speaker without the grille in place, that very well may be the way he listens to it! I don't mean to sound so chauvinistic, but when I bought my B&W 802F Specials, there was an optional "wife-hood" to place over the exposed midrange/tweeter assembly. Now there was a sexist item if there ever was one!

GMichael
02-17-2009, 06:53 AM
That's the ticket! :)

rw

I think that you should, "give him a ticket."

Auricauricle
02-17-2009, 07:33 AM
I'll tell ya where ta ticket!

hermanv
02-17-2009, 09:51 AM
<snip>
I don't mean to sound so chauvinistic, but when I bought my B&W 802F Specials, there was an optional "wife-hood" to place over the exposed midrange/tweeter assembly. Now there was a sexist item if there ever was one!I think you missed it, the wife hood was meant to go over the wife leaving the speaker operating at it's best and attenuating a great deal of audio spectral noise to boot. :D :D :D

GMichael
02-17-2009, 09:56 AM
I think you missed it, the wife hood was meant to go over the wife leaving the speaker operating at it's best and attenuating a great deal of audio spectral noise to boot. :D :D :D
Did it come with a rope? My wife is smarter than most and may even be able to figure out how to get the cover off if not tied down.

Hyfi
02-17-2009, 11:57 AM
My Dynaudio Audience 82s have the plug holes on the back so if you take the covers off the front, you have some place to put them. I would take that as designed to be off but I leave them onn due to the ugly black fronts. Mt JM-Labs on the other hand have the wood grain on front baffle so they look better without.

emaidel
02-17-2009, 01:34 PM
I think you missed it, the wife hood was meant to go over the wife leaving the speaker operating at it's best and attenuating a great deal of audio spectral noise to boot. :D :D :D

Damn! How could I have been so dumb?

simmel
02-18-2009, 02:59 AM
Well after an extended listening session last night the covers are back ON.
The only adjustment I made was to pull the speakers about two feet into the room away from the wall. With the covers off the highs got a bit tiring on my ears after about an hour, so I put the covers on again and that was much better certainly in the mid range and on the highs. The base on female vocals sounded a bit muddy but more than acceptable but on piano and guitar parts it was superb all round.
So they are staying ON. :thumbsup:

Ajani
02-18-2009, 06:15 AM
Did it come with a rope? My wife is smarter than most and may even be able to figure out how to get the cover off if not tied down.

No need for rope.... I find that a little Chloroform works perfectly...

GMichael
02-18-2009, 06:39 AM
No need for rope.... I find that a little Chloroform works perfectly...

You vary smart man.

Auricauricle
02-18-2009, 06:42 AM
I think you missed it, the wife hood was meant to go over the wife leaving the speaker operating at it's best and attenuating a great deal of audio spectral noise to boot. :D :D :D

Is that the device that we saw used in the film "Fargo"? Mebbe I should look into dat!

hermanv
02-18-2009, 08:35 AM
Well after an extended listening session last night the covers are back ON.
The only adjustment I made was to pull the speakers about two feet into the room away from the wall. With the covers off the highs got a bit tiring on my ears after about an hour, so I put the covers on again and that was much better certainly in the mid range and on the highs. The base on female vocals sounded a bit muddy but more than acceptable but on piano and guitar parts it was superb all round.
So they are staying ON. :thumbsup:Muddy bass is often a room effect. Moving the speakers even further from the wall may help.

According to George Cardas here are the best initial speaker placements:

The distance from the center of the woofer face to the side walls is:
Room Width times .276 (RW x .276)

The distance from the center of the woofer face to the wall behind the speaker is:
Room Width times .447 (RW x .447)

Every time I've tried these dimensions bass was excellent, next fine tune the treble with toe in. This will get you close to a correct final placement.

Kevio
02-18-2009, 11:17 AM
The distance from the center of the woofer face to the wall behind the speaker is:
Room Width times .447 (RW x .447)
That's in the middle of the room. Where do you sit?

E-Stat
02-18-2009, 12:41 PM
That's in the middle of the room.
Only if your room is square. Hopefully, that is not the case.

Cardas Method (http://www.cardas.com/content.php?area=insights&content_id=26&pagestring=Room+Setup)

rw

hermanv
02-18-2009, 04:21 PM
Conventional thinking was that speakers worked best placed along the long wall. I've used this equation to put them on the short wall with great success.

IBSTORMIN
02-18-2009, 05:53 PM
I took a cover off my speaker and found the cover isn't just cloth like I thought. There is a plastic sheet with closely spaced holes behind the cloth. No wonder it sounds different with it in place.

simmel
02-19-2009, 12:09 AM
That's in the middle of the room. Where do you sit?


I agree with Kevio, my room is almost square and this formula would put my speakers in the middle of the room, but if you add the space that the chest of drawers along the back wall takes up, then I would have about three feet between me and the speakers. So that puts the mockers on that then.
Not everyone has the advantage of a dedicated listening room and one which is specially built for the purpose (the nearest I have got which would fit this, is the hallway from the front door to the foot of the stairs). And if you do not have such a listening room then you have to make the best of what you have.
I go to my local Hi End dealers every so often to have a mooch and hopefully do some listening. He has got some serious Hi-Fi gear, but his room is also almost square and the speakers invariably placed approx three to four feet from the rear wall and about six feet apart some toed in and some not. This guy has been in the business for over twenty five years and knows what he's talking about.
Of course when I win the national lottery things will change but until then...... :frown5:

hermanv
02-19-2009, 09:29 AM
If you visit the Cardas site, he does offer a special placement solution for square rooms.

http://www.cardas.com/content.php?area=insights&content_id=33&pagestring=Room+Setup+8

This placement while less ideal regarding bass nodes does recognize the limitations for a room that has other uses besides dedicated listening.

Golden Rectangles, 1.618 (side wall) x 1 (rear wall) on one side and 1 (side wall) x 1.618 (rear wall) create diagonal lines for speaker placement in a square room.

JoeE SP9
02-19-2009, 11:29 AM
I agree with Hobby that it is speaker dependent.

The 'stats use stretched spandex, so as Kevio suggests, their affect is nil. This I determined with my previous stats which originally used a thicker weave cloth that did attenuate the highs. I later had a seamstress make some similar spandex socks which were acoustically transparent. In the HT system, I find the Polks are a bit bright, so I prefer leaving the grilles on (along with a 2 db treble cut). With the vintage double New Advents, I split the difference after much experimentation with not only grill position, but tweeter level. The grilles definitely make a difference and I prefer running the lowers on and the uppers naked. With them, it also opens up the soundstage a bit as well. I run the lowers on attenuate and the uppers on normal.

While I am largely an audiophile minimalist, I prefer having tweeter level controls on speakers. I find that speakers that are flat in an anechoic environment to be intolerably bright.

rw
Thanks E-Stat. I think I'll try some spandex covers on mine. My stats have that "double knit" fabric. I've always liked the sound of them naked but the agricultural look has always been too much for me.
Maybe I can have a picture silk screened on. Does anyone know if you can silkscreen spandex? Will it muddy up the sound?:mad2:

E-Stat
02-19-2009, 12:20 PM
Thanks E-Stat. I think I'll try some spandex covers on mine.
I updated my original 2+2s to the OFC wired panels back in '86 or so which required removing the socks. It was then I discovered the veiling effect of the stock cloth. For a while, I ran them naked and trying painting the frames white to match. Eventually, I had the spandex socks made. They need to be very tight vertically. So much so that it might seem at first they will not reach top to bottom. They were visually open to the degree that you could easily make out details of the panel grid. Also, I bypassed the fuse block and replaced the oxidized Monster cable. Those changes really opened up the top.

rw

JoeE SP9
02-19-2009, 02:52 PM
E-Stat;
Replacing the monster cable in the interfaces is something I hadn't thought of. It's a very good idea. Is there anything in particular you recommend.

Auricauricle
02-19-2009, 03:23 PM
Might to be able to find sumpin suitable at the local Victoria's Secret....

E-Stat
02-19-2009, 04:10 PM
E-Stat;
Replacing the monster cable in the interfaces is something I hadn't thought of. It's a very good idea. Is there anything in particular you recommend.
I didn't use any exotic wire as a replacement. The problem was the horrible oxidation that had occurred over time. It added an edgy "zing" to the sound.

rw

E-Stat
02-19-2009, 04:14 PM
Might to be able to find sumpin suitable at the local Victoria's Secret....
LOL! I ended up buying around fifty yards of "swimsuit fabric" at the local Hancock Fabric store to cover my DIY bass traps. Victoria's Secret would have been waaay too expensive. I'm sure the ladies there wondered what the heck I wanted with so much of that material. :)

rw

JoeE SP9
02-19-2009, 04:25 PM
Well E-Stat you've given me my project for this Saturday! I've got 20Ft. or so of TRS Megacable lying around. A quick look at it shows no discoloration. Now, where did I put my big soldering iron?

Auricauricle
02-19-2009, 07:28 PM
Yeah, but think it, E-stat....You would've DEFINITELY given the music yer undivided attention!

Wunner if they sell spikes? Y' know...for the speakers 'n such stuff.

simmel
02-20-2009, 12:04 AM
Good, now all I have to do is see if I can squeeze two large leather sofas, a book case, a large chest of drawers, one dinning table and six chairs, the wife's TV and the four foot square glass table into the bedroom and the kitchen, and I'm all set.
Now I can set up my HiFi in the almost empty living/dining room.

That's if I live long enough. :yikes:

Luvin Da Blues
02-21-2009, 01:57 PM
I prefer the grills off when I have vinyl spinning, otherwise, I usually have them on.