I had a conversation this week with a person who works at Linn and then another at B&W and they said something that I just did not believe but they were so sure in what they said.
"The speaker cloth or grills have no affect on sound quality at all"
I said that can't be possible, they said its true, what about HF?
"Nada, Zero! zip, zilch, Zero none!
I did not reply after that, but I just did not believe it.
What is the truth?
"The speaker cloth or grills have no affect on sound quality at all"
I said that can't be possible, they said its true, what about HF?
"Nada, Zero! zip, zilch, Zero none!
I did not reply after that, but I just did not believe it.
What is the truth?
I though that the fabric resonantes and this is absorbing sound and converting it into machanical movement plus I thought that the HF sound would be defused or even time delayed?
The fabric is a physical membrane and even though alot of sound is passing through it, It cannot be 100% transmission, there must be some reduction, even if its 0.05%
How many times have we looked at amplifiers and seen distortion figures of %0.05 distortion and then %0.005 which would you go for all things being equal.
I have seen many new expensive loudspeakers with foam around the face plate of the tweeter, because even the dimples for the screws affect the disperssion, so again I though a cloth grill would have a similar affect?
I do not personally like grills on speakers, I close my eyes when i listen to music so its not like I am looking at the speakers.
The fabric is a physical membrane and even though alot of sound is passing through it, It cannot be 100% transmission, there must be some reduction, even if its 0.05%
How many times have we looked at amplifiers and seen distortion figures of %0.05 distortion and then %0.005 which would you go for all things being equal.
I have seen many new expensive loudspeakers with foam around the face plate of the tweeter, because even the dimples for the screws affect the disperssion, so again I though a cloth grill would have a similar affect?
I do not personally like grills on speakers, I close my eyes when i listen to music so its not like I am looking at the speakers.
Depends on the design, I know our ATCs sound different with the grilles on to the grilles off, but IMHO that is more a design of the framework to hold the grille than the actual cloth, I listened to them without cloth in the grilleframe and with different cloth in the grille frame and could not distinguish any difference, without the frame though the change in baffle edge (they have a very harsh 1"or so step around the edge of the baffle that the grill frame sits in and makes it a nice radius) is what I believe is making the difference.
IMHO grille cloth probably does have a small influence on the sound, I do not know if it impares the 'quality' of the sound or not and it is far to small an issue for me to lose sleep over. Especially with issues like baffle edges and mechanical rigidity of cabinets to worry about.
Hows things Troy, not seen you about for a while.
IMHO grille cloth probably does have a small influence on the sound, I do not know if it impares the 'quality' of the sound or not and it is far to small an issue for me to lose sleep over. Especially with issues like baffle edges and mechanical rigidity of cabinets to worry about.
Hows things Troy, not seen you about for a while.
There is no debate IMO. I recall seeing Joe D' Appolito's measurments of varous speakers with and w/o grills and generally there was serious response abberations at mid and high frequencies. How much of this is due to the frame and how much to the grill itself is hard to say, but I suspect it both would have some effect.
OTOH, JBL L100's used acoustic foam for grill covers. -And we know what acoustic foam does...
C
OTOH, JBL L100's used acoustic foam for grill covers. -And we know what acoustic foam does...
C
Hi all,
I love grill clothes, don't like to see the drivers as I don't like to see the engine of my car.
But yes, it needs to be part of the design/developement. If you want to use a grill, you have to design the speakers to work with grills, not just ad grill (and frame) once your done. As example, the whole BBC Monitor series was designed and used with grills, and AFAIK all messurements and adjustments where taken with grills on. The BBC even added a metall grill on the tweeter of the LS3/5a, which improved the frequency response.
never say never
LC
I love grill clothes, don't like to see the drivers as I don't like to see the engine of my car.
But yes, it needs to be part of the design/developement. If you want to use a grill, you have to design the speakers to work with grills, not just ad grill (and frame) once your done. As example, the whole BBC Monitor series was designed and used with grills, and AFAIK all messurements and adjustments where taken with grills on. The BBC even added a metall grill on the tweeter of the LS3/5a, which improved the frequency response.
never say never
LC
Hi Bill 
I have been busy having a life instead of working myself into early grave.
Musical Fidelity on the famous MC-1 speakers used Velcro and a soft foam panel as grills, they also believed the plastic or wooden frame for the grill had an undesirable affect on the sound.
I had a chat with Hans Madsen from Vifa at the London Hi-fi show, his new corner loudspeakers use a mesh steel compression fit grill which is rounded like the cabnet, its sound profile has been designed with the grill in place, do all engineers designed speakers with the grill in place now?
I have been busy having a life instead of working myself into early grave.Musical Fidelity on the famous MC-1 speakers used Velcro and a soft foam panel as grills, they also believed the plastic or wooden frame for the grill had an undesirable affect on the sound.
I had a chat with Hans Madsen from Vifa at the London Hi-fi show, his new corner loudspeakers use a mesh steel compression fit grill which is rounded like the cabnet, its sound profile has been designed with the grill in place, do all engineers designed speakers with the grill in place now?
Talking about the grill clothe itself, I have measured -1.5dB absorption above 8kHz for thick clothe (like the one that West Coast speakers had in the 70s - good on dust) to -0.3dB for light women shocks like synthetic same as the one used in mic pop shields (poor on dust). For hexagon 6mm perforated metal grill there is about 1 dB rise above 10kHz. No comb filtering for all the above. Elastic strings like in Sonus Faber and Krell I have seen creating comb filtering from high mid upwards in independant technical reviews.
Now, grill frame is another story and its the main offender for comb filtering due to diffraction leading to audible coloration. Some manufactures go to lengths in integrating the frame design in an innocuous acoustical manner and tone up the tweeters as much as the minute absorption of the particular clothe demands. There are caution paragraphs in their manuals about non removing the grill for best results. In my experience 90% of the speakers don't really get measured and developed for wearing grills and even if the frame + clothe design is minimal they still perform with more clarity without them.
For DIY, a good test is to strech the clothe to be used in front of someones head that his / her voice is very familiar and ask the party to talk using words with many consonants. This way you can judge clothe absorption only. For very light frame design you can use thin cardboard, and cut out an 8 shape. Then use stand offs so it will be standing 2 cm in front of the drivers like a masque. No dust protection though.
Now, grill frame is another story and its the main offender for comb filtering due to diffraction leading to audible coloration. Some manufactures go to lengths in integrating the frame design in an innocuous acoustical manner and tone up the tweeters as much as the minute absorption of the particular clothe demands. There are caution paragraphs in their manuals about non removing the grill for best results. In my experience 90% of the speakers don't really get measured and developed for wearing grills and even if the frame + clothe design is minimal they still perform with more clarity without them.
For DIY, a good test is to strech the clothe to be used in front of someones head that his / her voice is very familiar and ask the party to talk using words with many consonants. This way you can judge clothe absorption only. For very light frame design you can use thin cardboard, and cut out an 8 shape. Then use stand offs so it will be standing 2 cm in front of the drivers like a masque. No dust protection though.
Attachments
salas said:
I have been asked to design a in wall hidden/stealth loudspeaker system which means I have to use a grill, because I had planned on colour coding the surround, cone and basket to wall, to what ever colour the customer wanted but even than is just not possible, grey to me is simple, I dont know what a dolphine grey is or a slate grey is, and alot of parts cannot be had in fine color tones.
This customer is artistic type and wont let me get away with anything plus they know there sound quality and I will not risk making a grill as an after thought, so I need to make a grill which is as invisible to sound as possible, I am not sure that is even possible?
I have to deal with customer service myself, and think what's impossible would be to convince your customer that there are trade-offs between looks and sound.
From my perspective, I'd ask the customer directly which of the two is more important to them.
It's not a matter of all or nothing, but whichever feature is less important to them is the one where you will have a "little" leeway in the design that they should easily be able to accept.
One thing to do is use material designed for grill cloths. Acoustical Solutions has been making acoustic materials for decades. They can supply the transmission vs. frequency of all of their grill cloth material. Typical loss at 20kHz varies from 0.5db to 1db, depending on cloth. I feel that when it is properly implemented, it has negligible effect on sound. Find out more here:
http://www.acousticalsolutions.com/
http://www.acousticalsolutions.com/
I like grilles on speakers because they give them a finished look; on the other hand I like to see the drivers too, so I'm working on building grilles that will be both acoustically AND visually transparent, as well as simple to make.
I'm using a frameless design, the screen being made of what's known as "expanded metal" - think aftermarket diamond-shaped automotive grille screen - the kind you see on a lot of modified import cars (available cheap and in bulk on eBay). It provides its own rigidity and has large "holes" that I assume will minimize diffraction and leave the drivers very visible.
For aesthetics (and safety due to sharp points where the metal is cut) I'm considering actually using lengths of automotive door edge guards around the perimeter - it just slips on and will look like a frame but without the bulk.
I will probably paint the screens flat black and glue small wood squares or triangles at the corners, to which I will attach adhesive-backed velcro for fastening to the speaker baffles.
Thus the grilles will not touch the baffles except at the small attachment points, hopefully allowing the sound to radiate much as it would without grilles or traditional thick frames, especially those that contact the entire perimeter of the baffles - I think those are probably the biggest offenders in terms of diffraction.
Depending on how they turn out, I may also cover them with black fiberglass screen door mesh - a la Home Depot - this will provide an even more finished look but will still be very sonically open and, though much less so, see-through so the drivers will still be somewhat visible - best of both worlds.
I may post pics when they're done - I've seen other ideas here in the past but this would be a great thread to resurrect pics of DIY grilles if people have them - anybody game?
I'm using a frameless design, the screen being made of what's known as "expanded metal" - think aftermarket diamond-shaped automotive grille screen - the kind you see on a lot of modified import cars (available cheap and in bulk on eBay). It provides its own rigidity and has large "holes" that I assume will minimize diffraction and leave the drivers very visible.
For aesthetics (and safety due to sharp points where the metal is cut) I'm considering actually using lengths of automotive door edge guards around the perimeter - it just slips on and will look like a frame but without the bulk.
I will probably paint the screens flat black and glue small wood squares or triangles at the corners, to which I will attach adhesive-backed velcro for fastening to the speaker baffles.
Thus the grilles will not touch the baffles except at the small attachment points, hopefully allowing the sound to radiate much as it would without grilles or traditional thick frames, especially those that contact the entire perimeter of the baffles - I think those are probably the biggest offenders in terms of diffraction.
Depending on how they turn out, I may also cover them with black fiberglass screen door mesh - a la Home Depot - this will provide an even more finished look but will still be very sonically open and, though much less so, see-through so the drivers will still be somewhat visible - best of both worlds.
I may post pics when they're done - I've seen other ideas here in the past but this would be a great thread to resurrect pics of DIY grilles if people have them - anybody game?
The only info I have on this is 2nd hand, but FWIW, Dan Wiggins was trying to design some sound absorbtion panels a couple of years back, so he tried measuring several types of "grill cloth" material with Praxis. One cloth that he measured was a white burlap type of material from a local fabric store. He told me that much to his surprise there was very little Frequency Response change (with or without the cloth). I would expect that the various weaves and compositions of the material would have some effect, but it indicates (to me) that the frame would have a more pronounced influence than some (many?) of the yardage that is often used. This is hardly scientific, but is an indication that perhaps some of the old adages about grills and grill cloth may be somewhat overemphasized, or just wrong.
If you want to be sure, or are an out and out purist, design your speakers without grills.
Best Regards,
TerryO
If you want to be sure, or are an out and out purist, design your speakers without grills.
Best Regards,
TerryO
I have been testing many types of materials which I could use but so far I can't decide on anything
I do not like the steel grill I have seen used on Epos loudpeakers models but I can't help but think its creating a reflection on the baffle, the grill surface area has 80% material removed via the round holes, these leaves a very solid 20% to reflect sound waves around or acts like a lens in the thickness of the grill, even though it is very thin at 0.8mm
There is something about the cloth that bothers me, I can't put my finger on it, the grill material needs to cover a whole wall, cost is not an issue the end finish and result is.
I have been thinking maybe I could use a electronic filter to replace any loss due to the grill which I would have to measure in the first place but I do not believe in using filters.
I think I may have bitten off more than I can chew with this design brief.
I do not like the steel grill I have seen used on Epos loudpeakers models but I can't help but think its creating a reflection on the baffle, the grill surface area has 80% material removed via the round holes, these leaves a very solid 20% to reflect sound waves around or acts like a lens in the thickness of the grill, even though it is very thin at 0.8mm
There is something about the cloth that bothers me, I can't put my finger on it, the grill material needs to cover a whole wall, cost is not an issue the end finish and result is.
I have been thinking maybe I could use a electronic filter to replace any loss due to the grill which I would have to measure in the first place but I do not believe in using filters.
I think I may have bitten off more than I can chew with this design brief.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.