Does a cloth grille affect the sound of a sub?

[KEW]

Doesn't sound like you are into DIY much, so just call the manufacturer and get a replacement grill (or just the grill frame if they will sell it). Buy some of the cloth like TLS recommended and take them to a local upholsterer. It'll cost you a bit, but I can't believe you are considering keeping a vigil on the cat. Sooner or later it is going to happen and it'll cost more to replace the driver than a second grill!

 

[Irvrobinson]

Doesn't sound like you are into DIY much, so just call the manufacturer and get a replacement grill (or just the grill frame if they will sell it). Buy some of the cloth like TLS recommended and take them to a local upholsterer. It'll cost you a bit, but I can't believe you are considering keeping a vigil on the cat. Sooner or later it is going to happen and it'll cost more to replace the driver than a second grill!

Good point. I'll look into it.

 

[Send Margaritas]

Parts Express sells grill cloth. It's thin, stretchy, and might be good to experiment with, if you get a manufacturers grill frame (was a good idea).

I did some 80's speakers, and the grill cloth thing was less intimidating than it looked at first. (I knew I could do it, but it was easier to do a decent job than I had anticipated.) They came out well with some hot glue and careful razor blade work.

 

[sholling]

Time to buy a dog with a taste for cats.

 

[Irvrobinson]

Time to buy a dog with a taste for cats.

Time to switch to a forum where the advice is better quality than recommendations for leaving my wife or getting the cat eaten by dogs? I know you guys are just kidding, but enough already.

 

[j_garcia]

I thought that was true for high frequencies, but for bass? That's where I'm thinking maybe not.

The waves for nearly all of the sounds coming from the typically crossed over at 80Hz sub are far too long to be meaningfully affected by a piece of cloth IMO Sort of like putting that piece of cloth in the ocean. It will diffuse and slow the flow down, but not enough to matter.

You could also consider a perforated or waffle style cover for the woofer, but those will also have some "blocking" effect, possibly more than acoustically transparent cloth.

 

[Irvrobinson]

Well, listening with the grille off sure does seem to sound different and better. I'm still with TLS Guy, but I'm thinking any grille is going to have a negative impact, so I'm going commando when I'm in the room, and a 22" bass drum head box covers the entire front of the sub when I'm not in the room. When company comes the grille will go on.

Since this is really the first time I've done extended listening sessions without the grille on, I'm surprised at how much cone movement I'm seeing. Not that it's actually flapping in and out, but I didn't think any cone movement would be visible from my listening seat. Perhaps I'm stressing the DD18+ more than I think. Perhaps I need a second one, or perhaps ditch the Velodyne and get a Funk 18.3 and have him put those bars over the drivers. (Mostly kidding... not completely kidding, but mostly kidding, I think.)

 

[KEW]

Back in the day, I remember my AR-3a woofer hopping around. You couldn't hear or feel anything, but you could see it easily enough. I was happy my amp had a subsonic high pass filter at 16Hz (or so it was labeled). When I turned it on, the woofer would calm down and I couldn't hear a difference.
That may have been only when playing the turntable?

 

[KEW]

Well, listening with the grille off sure does seem to sound different and better.

Well, if you want, you can still protect it from the cat. Go to the hardware store and ask for "hardware cloth" to make the grill with. It definitely will not create any back-pressure against the driver and your cat will find no joy in it.

 

[Irvrobinson]

your cat will find no joy in it.

And either will I...

 

[Nestor]

I was listening to some music yesterday, and the sun hit the grille cloth in such a way that I could see it pumping in and out with the bass notes of the music. So I wondered, would the sub sound better with the grille off? I removed the grille, and of course it sounded better, because I expected it to be better.

Thinking about it a little bit, the back pressure from the cloth to sub's cone must be inconsequential compared to the force of the voice coil. Or is it? With the grille off you can feel the force of the bass with your hand. Would the back pressure cause distortion? Just lower efficiency a bit? Or have no audible effect whatsoever?

For the time being I'm leaving the grille off, but the carbon fiber look of the sub's cone attracts the cat every time she walks by it when I'm listening. So I'd rather use the grille. If she scratches that driver I will be livid. (When I'm not listening I put a cardboard box for a bass drum head in front of the sub to keep the cat from treating it like a scratching post. Yes, it looks stupid, but my wife insists that if she has to choose one of us, well, she hasn't always had a husband, but she has always had a cat. There's no practical way to close off the room.)

Anyway, is it likely that the sub really does perform better without a grille cloth?

Save yourself the headaches and put the grill back on. No speaker company of any credibility would use a weave so thick as to affect the sound at sub wavelengths.

 

[Irvrobinson]

Save yourself the headaches and put the grill back on. No speaker company of any credibility would use a weave so thick as to affect the sound at sub wavelengths.

Yeah, that's what I thought, until I saw the fabric moving in and out with the music. As I mentioned, I've become convinced any fabric is detrimental, and I'm not messing up a $5800 sub with some kludgy solution. So, as I've posted, I'm going commando while I'm in the room, protect it by a thin box when I leave the room, and save the grille for company.

 

[pbc]

Yeah, that's what I thought, until I saw the fabric moving in and out with the music. As I mentioned, I've become convinced any fabric is detrimental, and I'm not messing up a $5800 sub with some kludgy solution. So, as I've posted, I'm going commando while I'm in the room, protect it by a thin box when I leave the room, and save the grille for company.

It's a $6k sub and the fabric is moving? Haven't read the entire thread, but have you tried contacting the manufacturer or dealer to see what they say?

I still can't imagine it impacting the sound. Could always go through a "blind test" by having someone blindfold you, then listen to the same few scenes over and over again with the person taking the grill on and off. Somewhat of a hassle though, but it will tell you whether you are simply "thinking" it is impacting the sound because you can see the grill on and moving?

That would drive me insane as well though.

 

[Irvrobinson]

It's a $6k sub and the fabric is moving? Haven't read the entire thread, but have you tried contacting the manufacturer or dealer to see what they say?

I still can't imagine it impacting the sound. Could always go through a "blind test" by having someone blindfold you, then listen to the same few scenes over and over again with the person taking the grill on and off. Somewhat of a hassle though, but it will tell you whether you are simply "thinking" it is impacting the sound because you can see the grill on and moving?

That would drive me insane as well though.

No, I haven't contacted Velodyne. My last highly technical encounter with their customer service folks was not especially satisfying. I have high confidence that Velodyne will stand behind the product if something goes wrong, but they haven't proven worth my time on technical discussions.

I've thought about a blind test of some sort, but the grille is so over-engineered it is a PITA to mount and dismount, so the test would be pretty contrived. As in I'd probably have to enter the room blindfolded and leave the room for the grille dismounts. Also, my previous experience with blind tests is that they suck for proving subtlety.

My intuition says the air pressure behind the fabric has got to affect the sub's performance, the only question is how much. So the grille is history for serious listening.

 

[BM1]

Well it would be simple enough to measure SPL changes using a good meter and test tones throughout the frequency range with the grille on and off. It'd be more difficult to compare sound quality though.

The placebo effect can sometimes be a problem with such minor changes without objectively testing the difference with quality test equipment.

 

[Hocky]

The grill on my F212 has fairly thick fabric wrapped on a heavy plastic frame. The plastic actually covers the entire surface of the speaker with round holes in it all over to allow sound transmission. At first glance, I thought that it appears very restrictive and that it had to be making a difference. We did some sweeps with the grill on and off and didn't find any real difference. I don't see any movement of the fabric even pushing it silly hard, but I don't think that the plastic frame would allow it to move either way.

 

[j_garcia]

If it has a grille, it is most likely designed to be used with it in place. If it was intended to be used with it off, the manufacturer would have stated such. On highs and midrange one can definitely tell the difference with them removed, but bass frequencies are longer than your typical room so there's no way a piece of cloth is going to make a significant difference. What you may be hearing as "more sound" is likely higher up in the range, but that does not necessarily mean "better".

 

[Irvrobinson]

Well it would be simple enough to measure SPL changes using a good meter and test tones throughout the frequency range with the grille on and off. It'd be more difficult to compare sound quality though.

The placebo effect can sometimes be a problem with such minor changes without objectively testing the difference with quality test equipment.

I did some SPL measurements a couple of days ago, and the results are not conclusive; that's why I was looking for technical theory. With 25Hz warble tones played back at 82db measured at my listening seat, there was approximately a 1 db difference in sound level, as measured at my listening seat, in favor of no grille. At 20Hz the difference was nearly 2db. At 31.5 Hz I must have a room mode, because fine positioning of the microphone changed the measurements enough I couldn't tell what I was measuring. At 40Hz the difference was about 0.7db.

When I replayed some of the tracks I thought "sounded" better, it was mostly the feeling of a bass "shock wave" that made me think there was a difference. I'm not sure if I could tell blind-folded, but I'd probably bet against myself unless the bet was under $10.

I haven't run bass distortion tests yet.

Overall, the results still seem to support leaving the grille off. The measurements are repeatable and consistent, but, who knows? I've noticed at these frequencies another person in the room, or my position in the room, affects the measurements.

 

[Steve81]

That is poor quality material and will affect the sound. The grill should not move and will change the compliance of the driver as well as other T/S parameters and change the tuning.

Do the Carter blow test. Get the grill up to your mouth and blow through it. You should feel very little increase in resistance compared to blowing in free air.

Do you have a link with further information on this? I tried searching for "Carter blow test speaker grille" on Google and came up with nothing relevant except a link here after 5 pages of looking.

I guess on the upside, it isn't something I have to worry about since my sub doesn't have a grille at the moment.

 

[Alex2507]

Do you have a link with further information on this?

no ...