# Restrictive Stock Speaker Grills?



## mojozoom (Feb 11, 2012)

My factory speaker grills look too restictive off axis to me. I've hunted threads on the subject and it sounds like it wouldn't be a big deal if the driver was handling low frequencies only, but as this is a two way active setup the drivers in the doors have to reach up to 3.5k. Won't those higher frequencies be partially blocked if the grill poses a restriction off axis?

Here's what it looks like:

On axis shot -









45 degrees off axis -









60 degrees off axis -









I'm wondering if I should go through the effort to cut these out and replace them with metal ones?

Thanks!


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## mojozoom (Feb 11, 2012)

82 reads so far but no comments.

This seems to be a topic that many are interested in!


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## gravel (Jun 24, 2012)

I'll bump it because I'm interested in the answer but have no useful knowledge to add..


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## Spyke (Apr 20, 2012)

Not gonna make any difference. Leave them alone. There have been guys that have covered there mids with cloth (for stealth reasons) and had zero issues.


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## Spyke (Apr 20, 2012)

I can't even see my mids. They are far forward in the kick panels almost concealed by the dash. I run them to 4k without issue.


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## minbari (Mar 3, 2011)

I tend to believe that what you say is right. higher freqs trying to get through those grills will be effected.

unless you are willing to make new grills, I would try it the way it is. to make new ones you would have to dremel out the current grill and replace it with grill cloth.


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## Spyke (Apr 20, 2012)

I'm surprised to hear you say that Mini. I thought this was a well discussed topic.


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## minbari (Mar 3, 2011)

Spyke said:


> I'm surprised to hear you say that Mini. I thought this was a well discussed topic.


look at home audio, you will never see a tweeter blocked by solid mesh or grills. only grill cloth. lower freqs dont matter, but higher, could be. moreso off-axis, since response is worse off-axis to begin with.

personally. I would try it before going to all the work of altering the door card.


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## Spyke (Apr 20, 2012)

minbari said:


> look at home audio, you will never see a tweeter blocked by solid mesh or grills. only grill cloth. lower freqs dont matter, but higher, could be. moreso off-axis, since response is worse off-axis to begin with.
> 
> personally. I would try it before going to all the work of altering the door card.


He's not putting a tweeter behind it. The question was about a midrange.


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## minbari (Mar 3, 2011)

ok, I went back and re-read it, I thought he said he has a set of 2-ways behind them.

in this case, I doubt it would make much difference.


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## Spyke (Apr 20, 2012)

Indeed. And like you mentioned, axis response is likely to be the limiting factor in this case.


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## 07azhhr (Dec 28, 2011)

When I had my 6.5's in my doors I found there to be a large difference between having the door panel on and having it off. Try this for yourself and see if this is true in your car too. My 6.5's were playing from 3.5k and down. 

Grill cloth is made to be 100% transparent.


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## Spyke (Apr 20, 2012)

07azhhr said:


> When I had my 6.5's in my doors I found there to be a large difference between having the door panel on and having it off. Try this for yourself and see if this is true in your car too. My 6.5's were playing from 3.5k and down.
> 
> Grill cloth is made to be 100% transparent.


You were prob hearing cancellation from the speaker playing partially into the back of the panel. Sound is not water. It doesn't spray out of the speaker and nor is sound(in the lower freq) blocked by grills of any type. Sound works by pressurizing the air. It doesn't care about the obstacle presented by the grill.


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## 07azhhr (Dec 28, 2011)

I built rings to prevent this. Basically I sealed the area surrounding the speakers and their grills so that cancelation could not happen. 

Low frequencies may not get blocked but higher frequencies do. Just placing your hand in front of a spreaker playing upper vocals will cause the volumn to decrease. Why does this hppen then if your theory is correct?

Remember we are talking about thick plastic solid grills and not cloth or thin screan materials.

My factory grills had the plastic area covering close to 50% of the speakers. This is very restrictive to even air movement since the air had to squeeze thru the 1/8" holes. 




> Hard Grilles
> Hard grilles can be made from many types of construction material including metal, wood or plastic. Some solid grilles are made from a board or sheet of material with holes drilled or cut for the sound to pass, while others are made with thin strips of material either crosshatched together or equally spaced in parallel.
> Because hard material is not free to move with the speaker's sound like soft material, the speaker's output level must be considered when designing the grille. A grille with more holes will allow more sound to pass but will offer less protection from small objects. A speaker with too much material in front of the driver will begin to distort at higher sound pressure levels, and in severe instances could damage the speaker, resulting in unwanted rattling at the least.


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## billymonter (Apr 15, 2009)

My experience with the grills is this: If you have the OEM system don't change the grills. It will make whatever little imaging you have shift or go away. You will notice it immediately!!. If you are changing speakers, EQ etc. It will make a huge improvement going from the hard plastic to cloth. I replaced the plastic ones in my 04 bmw 3 coupe with fabric and the difference was ver noticeable. Of course I had to EQ the whole system all over again. But it was a lot better.


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## mojozoom (Feb 11, 2012)

I ran some quick tests this morning with REW. In each case green is with the grill on and blue is with it off.

First the on axis comparison:








This looks the way we all would have expected. Bass below 100 hz drops off because the inner window weatherstip is gone, leaving a gap that lets the backwave out. There's a small increase from 2.2K to 4.4K, but other than that it's pretty much the same.

Now the 45 degree off axis tests:








Here there apprears to be some additional separation from 250 to 800 that wasn't present in the on axis comparison.

And the 60 degree off axis tests:








Now there's even more separation between 250 and 800, as much as 5 dB. The 2K-4K range shows a pretty substantial separation as well, again about 5 dB.


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## billymonter (Apr 15, 2009)

I wonder how the graphs change when the speakers are sealed against the grills eliminating the backwaves. That's how I did mine.



mojozoom said:


> I ran some quick tests this morning with REW. In each case green is with the grill on and blue is with it off.
> 
> First the on axis comparison:
> 
> ...


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## Spyke (Apr 20, 2012)

mojozoom said:


> I ran some quick tests this morning with REW. In each case green is with the grill on and blue is with it off.
> 
> First the on axis comparison:
> 
> ...


Well hold on. This doesn't really tell much. You said that with the door panel off it opens up a gap at the top of the door due to the weatherstrip not being there. This will affect all freq, not just bass freq.


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## mojozoom (Feb 11, 2012)

It's interesting how my eq settings compare to the grill attenuation plots. I've got to boost 500 & 630 and the 2K-4K range, the same areas that the curves show the grill impact to be at.


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## Spyke (Apr 20, 2012)

mojozoom said:


> It's interesting how my eq settings compare to the grill attenuation plots. I've got to boost 500 & 630 and the 2K-4K range, the same areas that the curves show the grill impact to be at.


So you're boosting the freq that the grill attenuates in order to match that roller coaster of a response curve?


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## minbari (Mar 3, 2011)

have to agree, with spyke (ducks)

unless you run your tests with a flat eq, the results dont mean much.


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## mojozoom (Feb 11, 2012)

minbari said:


> have to agree, with spyke (ducks)
> 
> unless you run your tests with a flat eq, the results dont mean much.


So you are proposing that the grill can tell if the response of my speaker is flat and then it attenuates the sound differently based on what it sees? It's just a dumb old piece of plastic.

I'd expect that the insertion loss due to the grill when measured off axis is relatively consistent regardless of the shape of the frequency response curve the speaker is emitting.

The measurements were taken near field so you don't see the room response included as you would at the listening position. The shape of the two lines in each graph means nothing - it's the difference between them that is important.


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## Spyke (Apr 20, 2012)

mojozoom said:


> So you are proposing that the grill can tell if the response of my speaker is flat and then it attenuates the sound differently based on what it sees? It's just a dumb old piece of plastic.
> 
> I'd expect that the insertion loss due to the grill when measured off axis is relatively consistent regardless of the shape of the frequency response curve the speaker is emitting.
> 
> The measurements were taken near field so you don't see the room response included as you would at the listening position.* The shape of the two lines in each graph means nothing - it's the difference between them that is important.*


I understand this. I didn't understand what you were trying to accomplish by bringing your eq settings up. Were those settings before or after and with or without the grill? Why does it matter that you needed to boost the freq that were attenuated by the grill? Your speakers sound fine with no eq as long as the grill is off? Also, I still think the open area at the top of the door when the panel is off will affect results.


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## BuickGN (May 29, 2009)

From a different perspective, my midbass has more bass with the grills on. I play them up to 500hz. I nearly removed the factory grills and covered with cloth but after driving around for a week with no door panel and then putting them on and getting the bass boost I decided not to mess with them. With my current midbasses I can feel air moving from the grills. I don't know why there's a boost but there is.


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## mojozoom (Feb 11, 2012)

I gotcha. The eq settings shown are what it takes to get a flat response from the passenger side mid when measured at my right ear. Those settings were in place before I did the tests. When you measure your speakers near field you really get an idea of the effect the car itself has on the sound.

If I can figure out how to fix the attenuation caused by the grill I should be able to bring my eq settings down at 500, 630, and 2k to 4k and still end up with a flat frequency response at the listening position. The sound that isn't escaping the grill probably impacts the sounds quality.

I'll probably cut out the areas between the honeycomb supports and stretch grill cloth across it. The silver ring comes off so I can tuck the fabric under it and reinstall it.


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## Spyke (Apr 20, 2012)

I'd be interested in your results. I think that it has more to do with putting a large piece of plastic in the radiant area around the speaker than the nature of the grill itself. Just my guess.


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## fuji6 (Feb 4, 2008)

What's interesting to me is the slightly increased output at 5k in the first two graphs.


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## mojozoom (Feb 11, 2012)

fuji6 said:


> What's interesting to me is the slightly increased output at 5k in the first two graphs.


I'd expect that to be a result of something in the plastic door panel resonating.

Once I have the mods done I'll retest. Right now i have 12 inches of snow to worry about.

Would love to see someone else run similar tests though.


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## mojozoom (Feb 11, 2012)

I revised the factory grills to use speaker grill cloth. I ordered dark grey, but it isn't really very dark. No biggie.

I started by cutting out the areas between the honeycomb bracing:









And super glued the cloth to the nice little ring the factory used:



























Here's the way it looks on axis now:









And at 45 degrees off axis:









And at 60 degrees off axis:









I'll do some additional testing and post the results when I do the left side. I've already had to cut many of the upper frequencies on the right side to keep it level with the left.

In listening, I noticed something unexpected: additional width on the right side. I doubt the same will occur on the left, but it's still a nice surprise.


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## LovesMusic (Mar 29, 2012)

Nice work, curious as to your definitive results, I had ventured similiarly with my door cards with the same thoughts...


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## Hanatsu (Nov 9, 2010)

Measured distortion/FR differences with the stock grill in place as well. I think it's a worthwhile upgrade. Looks nice btw ^^

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mojozoom (Feb 11, 2012)

I did some more listening this morning, and the stage is noticably higher on "Sweet Georgia Brown".

Since the left has the stock grill and the right has been modded, I can do some comparisons tests between them in the near field and see what shakes out.

One thing I am seeing is that the FR measured off axis isn't symmetrical across the speaker because it's actually offset to one side of the factory hole in the door card. Neiter the cone or the surround are covered when you look at them on axis, but when you get off axis toward the rear of the car the door card shields the driver.










I'm thinking that I need to revised the mounting baffle to move the driver forward about 1.25". Really it seem like the more forward and lower the driver would be in relation to the grill opening, the better, if I want to maximuze the direct path to my right ear.

You can see my foam seal in this pic as well - it's the brown thing.


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## 07azhhr (Dec 28, 2011)

Looks good. Might look even better with no more grill at all. The speakers are far enough in there that they should be protected from wandering feet lol. It is nt supprising to me that you noticed a upper range frequency increase. Moving the speaker forward and down should net you good results too. 

Now where is Spyke to tell us how this has nothing to do with the removing of the grill LOL. J/K Spyke well somewhat kidding .


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## Spyke (Apr 20, 2012)

It has nothing to do with removing the grills.


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## 07azhhr (Dec 28, 2011)

Spyke said:


> It has nothing to do with removing the grills.


There we go :laugh:.


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## therapture (Jan 31, 2013)

Dude, my stock gruills look almost exactly like yours. I was looking at them thinking of a way to chop them out and install the actual HAT grills I have.


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## therapture (Jan 31, 2013)

I do believe I will be at least cutting out the centers of those hexagons and doing the grill cloth. I also see I can better center the mid in the door card opening with baffle work, like you did. 

I am having a small issue, that is 2k and up related, but I will post that into a new thread.


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## mojozoom (Feb 11, 2012)

I finished the work on these this weekend, and have some test results to post. I was able to test the stock grills, then test again with the modified cloth grills. These tests were all run with a flat EQ.

Here's the on axis results:









The 45 degree of axis results were insignificant.

The 60 degree off axis starts to show more impact:









Here's the calculated difference between the two lines (60 deg off axis):









I'd expect that as you get even further off axis that the impact would continue to increase, but I didn't measure past 60 degrees. The increase in stage width from this modification is definately noticable in my car.


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## Niebur3 (Jul 11, 2008)

Bringing back an old thread. I recently measured my door speakers with the door panel on and then off. This is the passenger side with the EQ turned off:

Purple is with the door panel on, Pink is the door panel off:









Thoughts?


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## Hanatsu (Nov 9, 2010)

10dB boost in the midbass with panel on, looks like it seals off some of the backwave.

Weird that you lose output in virtually every other area though. Well, door IB isn't exactly an optimal solution, I think lots of issues would be resolved with enclosures. 

Is the speaker sealed against the speaker grill with foam etc?


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## Niebur3 (Jul 11, 2008)

It is not sealed with foam but it sits very close to the door panel. It would be curious to see how effective the foam is. I was curious if the boost was due to the loading from the door panel itself as the door is sealed really well.

I also think the dip at 1,500Hz is really curious.


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## jb4674 (Jan 29, 2015)

A bunch of unnecessary work just to try and justify chopping a decent factory grill for no good reason :lol:

The factory mesh grille on top of the honeycomb shouldn't restrict any high frequencies passing through.

Just out of curiosity, what speakers did you put in your car for your front stage?


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## Niebur3 (Jul 11, 2008)

jb4674 said:


> A bunch of unnecessary work just to try and justify chopping a decent factory grill for no good reason :lol:
> 
> The factory mesh grille on top of the honeycomb shouldn't restrict any high frequencies passing through.
> 
> Just out of curiosity, what speakers did you put in your car for your front stage?


I'm not understanding this response.

I had nothing to do with the OP and what he did with his doors. I am merely posting my findings from a quick test I did with my door panels this weekend.


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## Hanatsu (Nov 9, 2010)

jb4674 said:


> A bunch of unnecessary work just to try and justify chopping a decent factory grill for no good reason :lol:
> 
> The factory mesh grille on top of the honeycomb shouldn't restrict any high frequencies passing through.
> 
> Just out of curiosity, what speakers did you put in your car for your front stage?



It does affect the FR. I had a 10dB peak around 6kHz on my tweeters because of the oem speaker grill for example.


Sent from my iPhone 6 using Tapatalk.


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## steelwindmachine (May 15, 2017)

Resurrecting's an old thread too...

I have Morel 2-way single-plane 6.5" coaxials in my front doors behind stock grills. They're running off the factory HU for now, but I have a DSP and amp that I'm hoping to install some day to bi-amp the Morel's.

The custom MDF speaker adapters I used to get the Morels in have them angled upwards at 45*.

I'm wondering whether or not if might be fruitful to install Fast Rings to help seal the gap between the speaker face and the inside face of the door card's grills.

Anyone else experience satisfactory results by doing this?


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## oabeieo (Feb 22, 2015)

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