Speaker Grilles On Or Off: Which Way Sounds Better?

How do you listen to your speakers?

  • Grilles On

    Votes: 9 42.9%
  • Grilles Off

    Votes: 10 47.6%
  • What are grilles?

    Votes: 2 9.5%

  • Total voters
    21
S

shadyJ

Speaker of the House
Ratings
4,294 33 17
#42
I'm wondering with items like acoustically transparent screens just how transperent are they? Or could there be subtle issues of diffraction as well?
Screens can affect the sound, sometimes, but normally only at very high frequencies, we are talking like 18 kHz and above, stuff most adults wouldn't hear. Some companies like JBL actually compensate for screen loss in their cinema speakers, so they have just a tad more energy at the top end that they know that the screen will attenuate.
 
ryanosaur

ryanosaur

Audioholic Field Marshall
Ratings
891
#44
There is some evidence that diffraction can be audible, but no one really knows how audible these quantities are. The paper cited in the article that demonstrated the audibility of diffraction effects can be read in full here. In a normal listening environment, diffraction caused by grille frames isn't likely to be a serious detractor from the sound quality- unless that grille was just terribly designed. As was discussed in the article, poor speaker placement is going to cause much worse diffraction than most grilles.
Thanks again for linking back to that paper! Looks like audibility starts to happen probably at about 3-4dB in distortion, is my take away. Would be cool to have been in a test like that!
Cheers
 
TLS Guy

TLS Guy

Audioholic Slumlord
Ratings
7,413 17 25
#45
What ever the sonic merits, I think leaving the grill off leaves drivers too exposed and vulnerable. I test and tweak my speakers grills on.

Damage to any of these drivers that would be left exposed would be a significant financial knock..



This give peace of mind and security.



In my opinion, leaving drivers exposed is courting trouble and expense.
 
Sef_Makaro

Sef_Makaro

Audioholic
Ratings
60 1
#46
I usually have the grills on. For the loudspeakers I might take them off just for a different view. But I never take the grill offs my subs. We have a Corgi that chases the cat around the house and they sometimes slams into things. With the steel grill protecting my subs I don’t have to worry much about damage.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
243
#47
@shadyJ those pics came out great. What a snazzy studio you have there!

I want to add to the discussion, since I'm the one who foisted that Geddes article onto James. I told him I would never speak to him again if he didn't include it.

What James says about the threshold problem is really important. We should be very careful about talking about diffraction as not being audible. It's really unclear how audible it is. Direct testing of diffraction by physically causing it while holding all else constant has proven beyond difficult, so what Geddes did was surmise the effect of diffraction like this on a speaker. Group Delay. He then inserted differing amounts of group delay into test material to figure out what its audibility was like. it was a crude but accurate test, which is to say, it wasn't intended to establish thresholds. It was designed to see how it behaves.

It's not a non-linear distortion, its a linear distortion that behaves like a non-linear distortion. That is, its no different than something like an uneven frequency response or polar response, but its negative audible effect increases with volume. This actually suggests that our hearing system is non-linear. That was one of the interesting conclusions of the Geddes study, it supports one of the more current view on the human hearing model. Don't treat what he did like you would THD, it isn't that kind of distortion. It is not possible to measure it in a room. You can't take a measurement and then say, Oh you have 3% diffraction distortion, unfortunately.

As for the takeaway from this paper, I'll just say that when Geddes investigated this, his feeling was that diffraction is quite audible and should be avoided at all costs. He designed his speakers and his rooms to be minimal in this regard. Huge roundovers, very smooth and gradual transitions in the waveguides, extensive attention to detail in the mating of the driver to the waveguide, as well as optimization of the front area. He would give me a serious hard time every time I showed him my front stage and the speakers, TV, and equipment were all in line with each other. He was the one who really pushed me to stop doing what we all do.

How audible is all this? I don't know, Geddes study was a good start, his reasoning is sound enough, but there isn't enough research to conclude thresholds. It does seem likely that placing speakers inside a bookshelf or cabinet, ontop of a cabinet, against a wall, etc. are all more common problems that cause far more severe issues.

In fact, I think placing a speaker near a wall requires a special consideration. This causes a kind of acoustic mirror where by the output of the speaker is smeared in the time domain due to the slightly delayed nature of the reflection which is too delayed to be inaudible but too short in time to be filtered out by our hearing. This mirror causes a kind of diffusing of the sound along with a lot of reflections and diffraction effects which mess up the response. Placing a speaker near a wall is especially harmful.

James great article. Next! Let's measure just how significant each of these positions are on the response and then, maybe, test the audibility. Ok maybe not the latter bit, that would be pretty hard to do.
 
killdozzer

killdozzer

Audioholic General
Ratings
631 6 11
#48
@shadyJ damn shady, you really ripped the guts out of this one. The "choice" is clear in my case; grilles were never produced for my model. I do think it was taken into account though. :)

I wanted to share a related paranoia; sometimes I have kids over coming with their parents - my friends or family. I found myself thinking should I even stir their attention towards the speakers. :D:D:D I don't know how many of you here read the Dostoevsky's Idiot. There was this epic episode with Prince Mishkin attending a high society ball. Everyone knowing how clumsy the idiot is, they filled his head with instructions to avoid the cabinet where a famous, expensive vase stood. But his tragic character/destiny just turned this into blueprints, into a doted path of motion towards the vase. It ends with him braking it, what else.

So now I'm thinking should I even get children's focus and attention on the speakers. Some of you remember my ordeal when I dented the membrane (all good now, no worries),I have a hard time relaxing.

My brother was visiting some time back and after spending a few days at my place I told him what happened with my speakers and how easy it was to damage them. He went berserk!! He said; you MUST warn people, I have a habit to tap on a membrane to hear the sound it makes.:eek:

@Matthew J Poes where are the studio pics, I'd like to see these?
 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
243
#49
@Matthew J Poes where are the studio pics, I'd like to see these?
Oh I was teasing. I meant “photo” studio and was referencing the fact that those pics were in my basement. They are outside the theater in an area used as both an office for my wife’s tutoring business and my daughters millions of toys. It is nothing great to look at.

Here is my fancy voice over booth.

 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
243
#50
Thanks again for linking back to that paper! Looks like audibility starts to happen probably at about 3-4dB in distortion, is my take away. Would be cool to have been in a test like that!
Cheers
I can send you the files if you really want. It’s not nearly as fun as you think!

I have some stereo bass recordings for tests David Greisinger did. Those are even more fun.
 
killdozzer

killdozzer

Audioholic General
Ratings
631 6 11
#51
Oh I was teasing. I meant “photo” studio and was referencing the fact that those pics were in my basement. They are outside the theater in an area used as both an office for my wife’s tutoring business and my daughters millions of toys. It is nothing great to look at.

Here is my fancy voice over booth.
So no studio pics... :oops: And where's the leg room in your voice over booth?
 
I

ichigo

Full Audioholic
Ratings
36 2 1
#53
@shadyJ those pics came out great. What a snazzy studio you have there!

I want to add to the discussion, since I'm the one who foisted that Geddes article onto James. I told him I would never speak to him again if he didn't include it.

What James says about the threshold problem is really important. We should be very careful about talking about diffraction as not being audible. It's really unclear how audible it is. Direct testing of diffraction by physically causing it while holding all else constant has proven beyond difficult, so what Geddes did was surmise the effect of diffraction like this on a speaker. Group Delay. He then inserted differing amounts of group delay into test material to figure out what its audibility was like. it was a crude but accurate test, which is to say, it wasn't intended to establish thresholds. It was designed to see how it behaves.

It's not a non-linear distortion, its a linear distortion that behaves like a non-linear distortion. That is, its no different than something like an uneven frequency response or polar response, but its negative audible effect increases with volume. This actually suggests that our hearing system is non-linear. That was one of the interesting conclusions of the Geddes study, it supports one of the more current view on the human hearing model. Don't treat what he did like you would THD, it isn't that kind of distortion. It is not possible to measure it in a room. You can't take a measurement and then say, Oh you have 3% diffraction distortion, unfortunately.

As for the takeaway from this paper, I'll just say that when Geddes investigated this, his feeling was that diffraction is quite audible and should be avoided at all costs. He designed his speakers and his rooms to be minimal in this regard. Huge roundovers, very smooth and gradual transitions in the waveguides, extensive attention to detail in the mating of the driver to the waveguide, as well as optimization of the front area. He would give me a serious hard time every time I showed him my front stage and the speakers, TV, and equipment were all in line with each other. He was the one who really pushed me to stop doing what we all do.

How audible is all this? I don't know, Geddes study was a good start, his reasoning is sound enough, but there isn't enough research to conclude thresholds. It does seem likely that placing speakers inside a bookshelf or cabinet, ontop of a cabinet, against a wall, etc. are all more common problems that cause far more severe issues.

In fact, I think placing a speaker near a wall requires a special consideration. This causes a kind of acoustic mirror where by the output of the speaker is smeared in the time domain due to the slightly delayed nature of the reflection which is too delayed to be inaudible but too short in time to be filtered out by our hearing. This mirror causes a kind of diffusing of the sound along with a lot of reflections and diffraction effects which mess up the response. Placing a speaker near a wall is especially harmful.

James great article. Next! Let's measure just how significant each of these positions are on the response and then, maybe, test the audibility. Ok maybe not the latter bit, that would be pretty hard to do.
A lot of engineers and musicians mix with their monitors near a wall. The question is running something like the Genelec room correction software enough to fix this?
 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
243
#54
A lot of engineers and musicians mix with their monitors near a wall. The question is running something like the Genelec room correction software enough to fix this?
Are you referring to when the monitors are placed against or in a wall? If so, that is different. That only reinforces the low frequencies, which they can compensate for. Most good studios wouldn’t place the monitors next to side walls or the ceiling. The areas that would be most problematic. If they do, it’s often because they have narrow dispersion and it’s been built into the design. Some of the environment free designs integrate the speakers into the front wall and shape the side walls and ceiling to manage dispersion and diffraction. All of that is different from what James is talking about in the article.

Now one known bad habit of studios is the placing of monitors inline with the speakers, or even in front of them. That causes not only serious acoustic problems but also serious problems with the imaging. The engineer has to either know the problem and mentally compensate or else risk compromising the recording. I know which one i think is more common!

I’ve seen a number of studio redesigns where a main focus was getting the monitors out of the acoustic path. In fact one of the jobs I worked on specifically explored switching in an acoustically transparent screen instead of the LCD monitors. Ultimately the client chose a custom desk to help move the monitors out of the way. Basically everyone does it, even pros who know better, but some of them have good enough ears to recognize the problem and need or want a fix. Sound-on-Sound has done a few SOS episodes where the client didn’t even hear the problem until it was gone (which I suspect is most common).

I suspect a lot of people wouldn’t notice the severity of the problem until it was gone.
 
MR.MAGOO

MR.MAGOO

Audioholic Chief
Ratings
311 9 10
#55
For my system it's grills off, with this exception: The Definitive Technology Studio Monitor 65's and 55's and Pro Center 1000, all look ugly without grills (the top one for the 65's and 55's, and the center speaker).
 
CB22

CB22

Full Audioholic
Ratings
215 1 1
#56
Took the grills off and listened. And then put the grills on and listened. I don't think my ears can tell the difference :oops:. But I'll leave them off just for good measure.
 
ryanosaur

ryanosaur

Audioholic Field Marshall
Ratings
891
#57
Took the grills off and listened. And then put the grills on and listened. I don't think my ears can tell the difference :oops:. But I'll leave them off just for good measure.
Love having my BMRs naked!
Poes put up a good statement about the idea that so much is perhaps not actually audible... even flashing back to my TV question over a month ago...
But the point stands... what is audible? And at a certain point, how much does it matter? I can't hear the diffraction to my right, but I can see it when I look at the Audyssey measurement. To a certain extent, aesthetics probably don't affect sound quality that much in terms of grilles. But I'll still keep them off. ;)
 
djembeman

djembeman

Enthusiast
Ratings
3
#58
For 5 years I've run my home theater with grills on. Andrew Jones says that he designs his speakers with the intent to use them grills off. That's good enough for me. I just took all my grills off and have enjoyed seeing my drivers. Unfortunately my animals previously knocked over one of my towers and the grill nubs got broken off. I think because that grill doesn't fit as intended anymore, It affects the sound more. It's Interesting that my Infinity Primus speakers have grills that have less impact on diffraction/sound than others, but they are a little on the "distinct" side of looks. Maybe they were designed to be under a veil? I like leaving my subwoofer grill off, just because it's easier to emplace or remove the port plugs on my HSU VTF-2 MK5. We keep the dogs out of the basement now, so the speakers are more protected now than when a speaker got knocked over.
Resized_20190301_025320_8425.jpeg
 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
243
#59
Love having my BMRs naked!
Poes put up a good statement about the idea that so much is perhaps not actually audible... even flashing back to my TV question over a month ago...
But the point stands... what is audible? And at a certain point, how much does it matter? I can't hear the diffraction to my right, but I can see it when I look at the Audyssey measurement. To a certain extent, aesthetics probably don't affect sound quality that much in terms of grilles. But I'll still keep them off. ;)
It's a big unknown. We know from past research that how audible these kinds of effects can be dependent on how familiar a person is with the effect. That's the ol' expert vs novice argument. Once you know what to look for, it can become more evident. There is something to be said for being ignorant of these effects. When James and I do testing outdoors, we often can hear when a speaker or subwoofer is distorting, but the measurements will show low measured levels that probably are borderline audible. Why do we hear it so plainly? We've heard it so many times that we know what to look for. What does that mean? We've been ruined forever.

In any case, when it comes to this, my opinion is that, to some extent, this stuff is audible, but that its audibility depends on two factors: 1)The musical content containing the right sound information to actually excite the problem in a noticeable way. 2)This problem not being swamped by worse problems. A speaker with bad placement is likely creating more noticeable problems than is a speaker with its grill on. For many speakers, the problems introduced by the grill is fairly benign.

As for the musical content, this might be a surprise to some, but a lot of music contains very little energy in the high frequencies. I don't mean up above 20khz. I mean up above 10khz even. It obviously depends on what the music is, but a lot of music, especially acoustic music, has very little HF content. When that is true, the likelihood that those effects above 10khz are audible becomes low. There just isn't any musical content to excite it.
 
wilmeland

wilmeland

Audioholic Intern
#60
I still use an old pair of Monitor Silver Six speakers from the early 2000's for the majority of my listening and I really have a difficult time telling much difference with or without the grills. However, they are in a room that is probably on the lively side, which I think might make it difficult to discern diffraction from the grills.
One thing about these speakers though is the tweeters come with a metallic protective grill that is held in place by the magnetic field of the driver. That was immediately removed from the speakers right after I brought them home and it really opened up the sound of the tweeters. Fortunately the sales person pointed this out to me when listening to the speakers, as I probably would never have thought to try to remove those little grills otherwise. This made me think about how the shrinking numbers of dealers with good listening environments and knowledgeable staff really impacts our selection and use of equipment.
 

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