# How reduce/eliminate sibilance?



## Jsracing (Apr 1, 2011)

My tweeters are in the stock locations in the dash pointing straight up into the windshield. I've tried angling them atvarious angles and directions but none really helped. My car has a lot of glass around the tweeter so I think all the reflections are exacerbating the sibilance. The only angling that's helped reduce sibilance is is facing the tweeters toward the outer glass (side windows) but the screws up the sound stage. I've tried using my EQ to attenuate 2.2khz and 6khz ranges and it helps but at high volumes, the sibilance is still there and takes away from the enjoyment.
Anyone have any ideas to reduce or eliminate the sibilance while keeping the tweeter location the same?
Thanks.


----------



## The Baron Groog (Mar 15, 2010)

Active or passive? try raising crossover freq


----------



## alm001 (Feb 13, 2010)

flip the polarity of one, raise xover, or get a bigger tweeter.


_(then move them away from the windshield)_


----------



## 9mmmac (Dec 14, 2010)

Cut a small piece of foam and place it under the grille?


----------



## chefhow (Apr 29, 2007)

9mmmac said:


> Cut a small piece of foam and place it under the grille?


Or a piece of carpet without backing. U can also try cutting in the 1k-2.2 range as well.


----------



## Mic10is (Aug 20, 2007)

sibilance is 6.3 and 8k
harshness is 2-4k


----------



## Jsracing (Apr 1, 2011)

I guess is a bit of both sibilance and harshness.
Right now its running passive crossover with a point of 3200hz, so it's pretty high already. I can go active on my amp but not sure of I can go higher in crossover frequency or whether that would so pound good.
The tweeters are 28mm and barely fit in the stock locations. I can't put foam under the grill because the grill and tweeter are glued together into the mount (only way I could get them to fit). I could maybe put foam over the tweeter, but would that kill of other frequencies too much?
Would swapping polarity on one tweeter overly attenuate other frequencies also?
Thanks.


----------



## sqnut (Dec 24, 2009)

I'm not a big fan of inverting polarity on drivers. Chances are, you're getting reflections from both the windscreen and the dash. Not sure how much dsp you have at hand, but here are some things you can look at.

1. Turn the gains down on the tweets. If you have tweeter attenuation on your passive use that. Bi-amping the drivers and turning the gains down on the tweets also helps.

2. The range from 1khz-8khz is a PITA. Like Mic mentioned 6-8khz is sibilance, 5khz can cause listening fatigue, 2.5-3.5khz is the beaming range and causes harshness, 1.25khz can make the sound tinny. I don't know how many frequencies you control in this range but try cutting everything. Then go to your mid bass range 70-300hz and cut that a bit. That will help in maintaining the balance. 

3. The best way to manage reflections is via a dash mat. Not the most aesthetic solution but it works. Try covering your dash with a thick beach towel, you'll get an idea...


----------



## GranteedEV (Oct 17, 2010)

What you're likely hearing is a directivity mismatch between your midrange and your tweeter near the crossover region.

Try a 2nd order crossover, and lower the frequency if you can


----------



## spag_bace (Aug 24, 2006)

Generally I cut from 9k to 4k. small cut at 9k, big cut at 8k, small cut at 6.3k/5k/4k. Usually helps a lot.


----------



## ErinH (Feb 14, 2007)

spag_bace said:


> Generally I cut from 9k to 4k. small cut at 9k, *big cut *at 8k, small cut at 6.3k/5k/4k. Usually helps a lot.


IMO, if you're making these kind of changes through the entire passband, then you should consider either changing the install or getting new drivers.


----------



## Jsracing (Apr 1, 2011)

The passive crossovers are currently set to their max attenuation of-3db. The crossover rolls off at 6db/oct so it's not very steep. My EQ has 7 frequencies: 50, 125, 315, 750, 2200, 6000, 16000. Cutting 6khz seems to have the most impact but there's still some sibilance.
Sounds like I need to go active to resolve the harshness and sibilance issues. Going active would let me drop the gain of the tweeters more and have a steeper filter rolloff. I'll try a beach towel on my dash too to see if reflections are a big contributor.


----------



## sqnut (Dec 24, 2009)

I like to cut all my drivers on steep slopes. My mids and tweets are cut at 2.5khz with both drivers on a 24db slope. Steep slopes with the right amt of tuning ability = clearer imaging and lifelike sound.

The eq is meant for attenuating not boosting. I have a 16 band eq on my hu and 11 frequencies are attenuated. 5 frequencies 20/31.5/50/500 and 20khz are run flat at 0/0. Everything else is cut.

With your 7 band eq I would cut 750 / 2.2 / 6khz something like 750 -4db, 2.2kz -2 db, 6 khz -4-5 db. This is just an indication you will have to tune to what sounds best for your equipment, install, environment etc. Next I would go to 125hz and 300hz and trims a bit there. 

Try the towel experiment. You'll be surprised at how much reflections screw up your sound.


----------



## Jsracing (Apr 1, 2011)

I guess im heading in the right direction as the only frequencies cut on my eq are 750, 2.2, & 6k. Everything else is flat except a slight boost on 50.


----------



## computerjlt (Nov 29, 2010)

when i left/right balanced my EQ after setting time alignment and flattening response with the EQ i got rid of pretty much all sibilance in my 3 way setup


/edit: to make more sense out of that 1, i set crossovers and time aligned the drivers, then i used an rta and flattened the response of the overall system then i played test tones at the 30 something eq frequencies and cut/boosted left and right seperate to center that frequency. before i did that i had a slight sibilance problem; now i have none


----------



## SSSnake (Mar 8, 2007)

> 2.5-3.5khz is the beaming range


For what size driver? Drivers beam at different freqs depending primarily on the driver size. Without knowing the size of the driver I don't how you can make this statement. Additionally drivers tend to beam at the top of their passband not the bottom. The mid may be beaming in this range (depending upon size and crossover freq) but the tweeter should not be (unless this is a VERY large tweeter and if so it would be beaming at any frequency above the onset of beaming)


----------



## Brian Steele (Jun 1, 2007)

Just a question: have you tried different tweeters? I had the same problem with a pair of old BA tweets in a previous install. The only "fix" that worked was to replace them.


----------



## subwoofery (Nov 9, 2008)

As Mic stated, sibilance is between 6kHz-8kHz (I usually like to lower 8kHz a bit more). 

This chart should help 

Ohh, you need more EQ bands  or find a half-din one that EQs around 8kHz... 

Kelvin


----------



## Jsracing (Apr 1, 2011)

Speakers are Morel Dotech Ovation 6s, so 6.5" midbass and 28mm tweeter. I don't think its the tweeters themselves as everything I've read and heard of various morel tweeters are laid back...i think it's more the environment not playing well with the tweeters which leads me to wonder if any tweeter would play nice.
I have no other tweeters to try.


----------



## sqnut (Dec 24, 2009)

SSSnake said:


> For what size driver? Drivers beam at different freqs depending primarily on the driver size. Without knowing the size of the driver I don't how you can make this statement. Additionally drivers tend to beam at the top of their passband not the bottom. The mid may be beaming in this range (depending upon size and crossover freq) but the tweeter should not be (unless this is a VERY large tweeter and if so it would be beaming at any frequency above the onset of beaming)


1. most mid drivers in cars are 5.25-6.75" apprx. As confirmed by the OP, his mids also fall in this size range. Hence a beaming range that I mentioned. 

2. I never said the tweets would be beaming in this range. The typical 1" tweets would beam around 12.5-13khz. 




Jsracing said:


> Speakers are Morel Dotech Ovation 6s, so 6.5" midbass and 28mm tweeter. I don't think its the tweeters themselves as everything I've read and heard of various morel tweeters are laid back...i think it's more the environment not playing well with the tweeters which leads me to wonder if any tweeter would play nice.
> I have no other tweeters to try.


The environment plays a big part. Which is why in a car, even the most laid back tweet will need attenuation.


----------



## 14642 (May 19, 2008)

Depending on the crossover and the midrange, it may not even be the tweeters. If you're using a passive network that came with the speakers, then it's probably OK, so long as it has a low pass for the mid.

In any case, trying a thousand tweeters, inverting the phase, screwing around with the crossover or throwing away those speakers and getting new ones is the wrong way to fix this. Get a real EQ and an analyzer (RTA) of some kind. That's your best bet.


----------



## sqnut (Dec 24, 2009)

Andy Wehmeyer said:


> Get a real EQ and an analyzer (RTA) of some kind. That's your best bet.


Then what would happen to all the nay sayers who believe eq destroys the purity of sound and that install > dsp?

But yeah, a good eq with separate L/R control and managing reflections off your dash for them tweets mounted high, are ideal solutions.


----------



## ErinH (Feb 14, 2007)

sqnut said:


> install > dsp?


I've never known a case where this isn't true.

If you can 'fix' the issue via the install without a negative tradeoff I see no reason why you wouldn't do it. Install it right means less work to do on the back end.

Sort of like on vs off-axis tweeters. Tradeoffs. I like on-axis installs when possible... less comb filtering for one. Can't fix comb filtering via an EQ. 
I don't care if someone can make it work; I'm not arguing that... you still have comb filtering issues at the end of the day that has to be tweaked to sound better. If you can resolve it in the install, you don't have to 'fix' it via a DSP.

Just sayin'.


----------



## Jsracing (Apr 1, 2011)

Being constrained to the stock locations (want to keep it as stock looking as possible, previous car was stolen with all my car audio taken), what other installation methods/things can I try?
Currently, the tweeters shoot straight up (almost, about 3-5deg off from perfect vertical) into the windshield. I've tried putting them at about a 30deg angle from vertical (60deg from horizontal) which is what one of the cups that come with the tweeters angles them at and faced the tweeters in different directions (on-axis facing me, off-axis at varying degrees, facing each other (shooting toward other tweeter on opposite side of car), facing away from each other (shooting toward the side window), etc.) and none had any good effect of toning down the sibilance except one: facing them towards the side windows, but that completely screws up the sound stage making it seem like there's 2 sources.
Let me know if there are other ideas I can try with the constraints given.

Just as reference, I have Morel Tempos in my other car with the tweeters in the door off-axis. Different tweeters from the "higher end" MT-12s that come with the Morel Dotechs I know, but they don't have sibilance (at least not that bothers me). These Tempo tweeters are only 3/4" while the Dotech MT-12 tweeters are 28mm.

Thanks.


----------



## SSSnake (Mar 8, 2007)

> most mid drivers in cars are 5.25-6.75" apprx. As confirmed by the OP, his mids also fall in this size range. Hence a beaming range that I mentioned.
> 
> 2. I never said the tweets would be beaming in this range. The typical 1" tweets would beam around 12.5-13khz.


Well since the discussion was about tweeter sibilance I was trying to decipher how this was relevant. Evidently it was not. Got it, carry on.


----------



## SSSnake (Mar 8, 2007)

> Being constrained to the stock locations (want to keep it as stock looking as possible, previous car was stolen with all my car audio taken), what other installation methods/things can I try?
> Currently, the tweeters shoot straight up (almost, about 3-5deg off from perfect vertical) into the windshield. I've tried putting them at about a 30deg angle from vertical (60deg from horizontal) which is what one of the cups that come with the tweeters angles them at and faced the tweeters in different directions (on-axis facing me, off-axis at varying degrees, facing each other (shooting toward other tweeter on opposite side of car), facing away from each other (shooting toward the side window), etc.) and none had any good effect of toning down the sibilance except one: facing them towards the side windows, but that completely screws up the sound stage making it seem like there's 2 sources.
> Let me know if there are other ideas I can try with the constraints given.
> 
> ...


I'm not familiar with the car/dash geomoetry but I would guess that if you are using stock locations then you are getting significant reflections off of the dash/instrument cluster. If you don't want to use any other location you are probably limited to using a dash pad to combat this affect. Mid to high on the a pillar is a favorite location of mine and the tweets could likely be recessed into the a pillar to keep it away from prying eyes. I have heard several cars with the tweets behind a flush grill on the a pillar that turned out well and were virtually undetectable. Otherwise you are limited to using some cut on the EQ. BTW - I would expect the problem to be coming primarily from the driver's side tweet if the instrument cluster is the problem and you will likely want an indpendent L/R EQ to address this properly.

GOOD LUCK!


----------



## subwoofery (Nov 9, 2008)

Did you try to reverse the polarity of your tweeters relative to your mids? You might be experiencing phase distorsion at the Xover. 

Kelvin


----------



## Jsracing (Apr 1, 2011)

I wouldn't be surprised if I'm getting a lot of reflection from both the windshield and dash. For the setup, just picture the flat portion of the dashboard about 3" from where it meets the windshield (closet to the hood)...that's where the tweeters are in each corner, firing straight up into the windshield.

I haven't tried the polarity switch yet...will do this weekend. Need to plan for a family trip tomorrow.

One more note that I forgot to mention:
The sibilance (and harshness) is less irritating if I listen in the center of the car (between the 2 front seats). Don't know if this points to one cause more than another.


----------



## sqnut (Dec 24, 2009)

bikinpunk said:


> I've never known a case where this isn't true.
> 
> If you can 'fix' the issue via the install without a negative tradeoff I see no reason why you wouldn't do it. Install it right means less work to do on the back end.
> 
> ...


Agree 100%. My comment was more for the crowd that says if you install it right you don't need dsp. Hence install>dsp. There are enough of them here. But sure, whatever you can fix / improve with install, you must. Then use dsp.

How's the 2011 season going? Say hiya to Aaron if you run into him. 



SSSnake said:


> Well since the discussion was about tweeter sibilance I was trying to decipher how this was relevant. Evidently it was not. Got it, carry on.


Please go back to post # 8 and re-read my point 2. I am trying to explain why the entire 1-8khz range needs to be attenuated. Sibilance and beaming are part of this range. However, thanks for nit picking. Carry on.


----------



## sqnut (Dec 24, 2009)

Jsracing said:


> I wouldn't be surprised if I'm getting a lot of reflection from both the windshield and dash. For the setup, just picture the flat portion of the dashboard about 3" from where it meets the windshield (closet to the hood)...that's where the tweeters are in each corner, firing straight up into the windshield.
> 
> I haven't tried the polarity switch yet...will do this weekend. Need to plan for a family trip tomorrow.
> 
> ...


When you sit in the centre, you're minimizing path length difference between the drivers on either side as well as bringing them more equally on axis. Hence better frequency response. 

The fact that you mentioned this makes me thing Snake has a point. Since the near tweet is the driver closest to you, you're hearing that first and that is pulling everything towards that source. I'm assuming you're not using time alignment.


----------



## ErinH (Feb 14, 2007)

just for kicks, throw a towel on the dash to mimic a dashmat. See if the sibilance goes away or lessens.


----------



## Jsracing (Apr 1, 2011)

No TA. I'm planning on TA later with a new HU, but not for now.

I will try definitely the towel first, but I'm about to head out on a family trip this morning. Will report back on Saturday. Keep the suggestions coming though if you guys come up with more ideas. Thanks very much for all the help.


----------



## jalba (Dec 20, 2010)

Dynamat your windshield, at least 2 layers. Then to combat the unnecessary side effects that dynamat has on highs, cover it with some 18ga sheet metal and seal all the edges with rubber cement, then cut out a hole (or square, if you prefer) for you to see out of.


----------



## SSSnake (Mar 8, 2007)

> Dynamat your windshield, at least 2 layers. Then to combat the unnecessary side effects that dynamat has on highs, cover it with some 18ga sheet metal and seal all the edges with rubber cement, then cut out a hole (or square, if you prefer) for you to see out of.


WORKS EVERY TIME! 



> Please go back to post # 8 and re-read my point 2. I am trying to explain why the entire 1-8khz range needs to be attenuated. Sibilance and beaming are part of this range. However, thanks for nit picking. Carry on.


OK here is where we differ and maybe why I interpreted the beaming portion of your post as off topic or unrelated. I don't believe that sibilance is in the entire 1-8khz range. Therefore I don't believe that you can make the suggestion that the entire 1-8khz range needs to be cut. As a matter of fact I think this suggestion is counterproductive. Sibilance typically occurs when 6-8Khz are higher magnitude than the surrounding freqs (that's why you don't typically get large increases in sibilance when you turn up the volume knob - it is not an absolute level issue but a relative level issue). Could there be other issues in this range causing problems? I definitely agree there. Could some of them be compounding the sibilance issue? Yep! Cutting that broad of a band (3 octaves) is, IMO, not a good solution.


----------



## sqnut (Dec 24, 2009)

Cutting 3 octaves is not a good solution? How about the fact that you actually need to cut 7-8 depending on your driver placements?

Andy has posted frequency response graphs of output measured 1" from the mid and that at ear level in the seat. Look at those graphs. Tell me how many octaves you have to cut to get the response at ear level close to that at the driver? 

All this talk about keeping the signal 'pure' and true to the original recording is crap if you don't use TA to set arrival times (which by the way are not dead on identical) and eq to cut '95%' of frequencies while balancing for L/R. Ask Erin, or Kirk or Aaron, or Mic or BigRed how many frequencies on the 31 band eq are cut.

If you're deep down the rabbit hole, you would know the two basic rules with sound in a car. Everything is linked and everything is a compromise, you're constantly choosing one over another.


----------



## ErinH (Feb 14, 2007)

sqnut said:


> All this talk about keeping the signal 'pure' and true to the original recording is crap if you don't use TA to set arrival times (which by the way are not dead on identical) and eq to cut '95%' of frequencies while balancing for L/R. Ask Erin, or Kirk or Aaron, or Mic or BigRed how many frequencies on the 31 band eq are cut.


IIRC, the most cut of any band I have is about 1dB and a couple bands from 300-20khz. Before the re-install I had a LOT of eq work going on to remedy problems. I changed the install up and had to use MUCH less. The system sounded much better with the install change alone.

I won't get in to the argument that 'too much processing' makes a system sound bad. I don't personally put much weight in to it myself.
I think Charles and I are on the same page, though; if you have to use a LOT of eq across that broad of a band to rid a single issue then you should consider other options (re-install or new drivers). Excessive eq'ing shouldn't be entirely necessary unless you're making serious compromises (ie: I want hidden tweeters so I need to do a lot of processing to make up for it).

It's not about having a processed sound; it's about removing things that you don't realize. A graphic EQ isn't a pure, high-Q, notch filter. It affects other things around it. That's where the real issue is with going heavy on the EQ to fix something.

My $.02.


----------



## sqnut (Dec 24, 2009)

Erin,

I don't have an issue with the drivers. Both the SR mids and the Scan tweets are excellent drivers. I have really sucky install locations. The mids are mounted high on the doors and the near one fires directly into the steering column 7" from the mid. There is 0 gap between the mid and the dash. I guess Ford doesn't have audiophile designers / engineers. 

So yes I would use a ton more dsp than normal. If I didn't have 10 thumbs and could actually use my hands and brains to 'make' something, yes I would probably use less eq. But I would still be cutting everything.....just less than what I'm doing now. 

I don't know about processed sound but if you're a Sting / Police fan and are familiar with 'Tea in The Sahara' there are two things that will strike you, the stand up bass and kick drums at the beginning of the song and the fact that Sting seems to be blowing the "OOOOOO' at your left shoulder at the end. For a right hand drive.

I go back to Andy's charts that are made for a better install than mine. And that needs a crap of eq. 

How do these threads get so OTT?


----------



## Jsracing (Apr 1, 2011)

Err, getting a bit back OT...since beaming has been brought up a few times, can someone explain what it is?
Thanks for all the help, even if there's a bit of disagreement. The more ideas, the better.
My locations are VERY compromised with the midbass being at the bottom of the doors facing center of vehicle and tweeters in dash shouting at windshield. I know I'm not going to compete on SQ, but just want to get rid of the things that take away the enjoyment of my system.


----------



## jalba (Dec 20, 2010)

Jsracing said:


> Err, getting a bit back OT...since beaming has been brought up a few times, can someone explain what it is?
> Thanks for all the help, even if there's a bit of disagreement. The more ideas, the better.
> My locations are VERY compromised with the midbass being at the bottom of the doors facing center of vehicle and tweeters in dash shouting at windshield. I know I'm not going to compete on SQ, but just want to get rid of the things that take away the enjoyment of my system.


Let me google that for you


----------



## Bluliner (May 16, 2011)

This is going back years ago, but I had a customer with a very-very-very high end install with similar issues. Placement really didn't help much, that raspyness was always there. EQ'ing would fix one problem and create others. We tried adding several layers of speaker grill cloth over the tweets to calm them down, still never sounded right. 

How did it get fixed? Cheap-ass speaker wire. 

The install had Nordost (the PITA flat wire that you have to fold a bazillion times to make it sit flat under the carpet. Perhaps there was just too much signal or there was sort of voodoo curse cast on the speaker leads, but when we swapped it for cheap bulk wire...it sounded awesome. 

I'm still scratching my head wondering how that happened. But it worked and the customer was happy...all was well in the world for that one evening. 

(I want to say they were old MBQ's...but I'm not positive.)

So, there's something else to think about; your speaker wire. If it's factory and going thru cheap wire & a bunch of plugs vs. higher-end wire. You'd think the higher end wire would sound better 10 out of 10 times, but my own experience tells me otherwise. 

Just keep in mind I've only ever encountered something like this once. It was so strange I don't think I could forget it even if I tried.


----------



## Brian Steele (Jun 1, 2007)

Jsracing said:


> Err, getting a bit back OT...since beaming has been brought up a few times, can someone explain what it is?
> Thanks for all the help, even if there's a bit of disagreement. The more ideas, the better.
> My locations are VERY compromised with the midbass being at the bottom of the doors facing center of vehicle and tweeters in dash shouting at windshield. I know I'm not going to compete on SQ, but just want to get rid of the things that take away the enjoyment of my system.


I'm going to bet that your "problem" is happening around 5 kHz or so, but it might be useful to do a frequency response sweep to confirm. If you've got a PC with a sound card, you're half-way there to being able to do this without expensive equipment.

Did the stock tweeters have an filters or xover on them? If so, please share details, thanks. I'm guessing that they were "presence" tweeters crossed over very high, but information on the stock filter or x-over will confirm.


----------



## Jsracing (Apr 1, 2011)

My PC crapped out on my about the end of last year so I do almost all my surfing on my phone. 

The stock setup, while it had the tweeter pods, there were no tweeters in them. Instead, I just had full range drivers in the doors. The higher model of my car has tweeters, but if it's anything like all the honda components I've seen, the filtering is done by a cap on the teeter inputs. No idea what frequency they're crossed over at though.

In general, what's better, high or low crossover point? It always seemed like the higher end models of a brands components crossed over at a lower frequency, but HAT crosses over all of theirs above 5khz.


----------



## Brian Steele (Jun 1, 2007)

Jsracing said:


> The stock setup, while it had the tweeter pods, there were no tweeters in them. Instead, I just had full range drivers in the doors. The higher model of my car has tweeters, but if it's anything like all the honda components I've seen, the filtering is done by a cap on the teeter inputs. No idea what frequency they're crossed over at though.


I'm going to guess that in the "higher" model of your car, they used the same full-range drivers in the doors and crossed the tweeters over very high. In my Tucson for example, the stock tweeters were connected in parallel with the front door "full range" speakers, with only a 2.2uF capacitor in series for filtering. x-over point works out to around 18kHz @6dB/octave I think. I decided not to reinvent the while and deployed a "full-range" (DIY coaxial) design for the doors and small tweeters crossed over very high for the sail panels, and I'm quite happy with the results.




Jsracing said:


> In general, what's better, high or low crossover point?


That would depend IMO on the driver's characteristics and its intended use.




Jsracing said:


> It always seemed like the higher end models of a brands components crossed over at a lower frequency, but HAT crosses over all of theirs above 5khz.


Ok, warning - the following is my opinion only...

X-overs are generally used for two reasons - (1) to prevent certain frequencies from reaching drivers not designed to handle them, and (2) to achieve a target response curve. 

Now, if the designer has NO IDEA where the speakers are going to be mounted in your car (kick panel, door, sail panel, A pillar, dash, etc.), much less the actual car that the speakers are going to be installed in, how on earth can they achieve the #2 requirement? 

The only solution I see is to design and use your own x-overs to get the best results for the drivers you've chosen for your car *in the locations that you've chosen to use them*, and use active EQ to correct and response anomalies that it will be too expensive to treat with passive filtering.

In your case, because your tweeters are mounted so close to the windscreen, you may have to use a higher x-over point, or use EQ to cut the response at the lower end of its frequency range as suggested by others here, and/or relocate the tweeters to somewhere else where they produce better results.


----------



## Jsracing (Apr 1, 2011)

Yes, my car is the same way...a full range driver in door and tweeter with a cap.

My amp can go up to about 4900hz, so I'll try going active to see if that fixes it of the othersuggestions don't work.


----------



## SSSnake (Mar 8, 2007)

Alright this will be my last communication with SQnut on this subject - as we seeme to be pulling this off topic (however I believe this discussion will help the OP).

This is the initial quote I had/have issue with:



> 2. The range from 1khz-8khz is a PITA. Like Mic mentioned 6-8khz is sibilance, 5khz can cause listening fatigue, 2.5-3.5khz is the beaming range and causes harshness, 1.25khz can make the sound tinny. I don't know how many frequencies you control in this range but try cutting everything. Then go to your mid bass range 70-300hz and cut that a bit. That will help in maintaining the balance.


You went on to counter with this:



> Cutting 3 octaves is not a good solution? How about the fact that you actually need to cut 7-8 depending on your driver placements?
> 
> Andy has posted frequency response graphs of output measured 1" from the mid and that at ear level in the seat. Look at those graphs. Tell me how many octaves you have to cut to get the response at ear level close to that at the driver?
> 
> ...


First, I am not a no-EQ purist. I run an MS-8 and two Behringer DCX 2496s. So obviously I believe in the value of EQ (particularly in a car environment). The issue I have with your suggestions is that they will likely leave the OP with MORE problems instead of less. You assert:



> Cutting 3 octaves is not a good solution? How about the fact that you actually need to cut 7-8 depending on your driver placements?


Which is total BS. How does blindly cutting 7-8 octaves help anyone? If you are trying to say that you should listen and use an RTA to make adjustments in this range, then I agree. But I would go on to say thay you need to listen, measure, and make adjustments throughout the entire audio spectrum (not sure why you limited it to 7-8 octaves). However, the problem is that you DON'T just apply some uniform cut through this range. Your initial suggestion to the OP to:



> try cutting everything


is not beneficial and will not help. It is very likely going to lead to additional problems. For one, most EQs (unlike the graphic in the MS-8 and my Behringer pieces) don't do target curve matching. They implement the cut at the specific freqs of the filter and with the associated Q. This is going to lead to significant ripple in the FR. Additionally, this will have negatvie affects on the spectral balance (balance throughout the frequency range) unless he had issues there to begin with (which if he did this could either help or hurt - crapshoot).



> All this talk about keeping the signal 'pure' and true to the original recording is crap if you don't use TA to set arrival times (which by the way are not dead on identical)


See previous comments about 'pure'. I do believe in time alignment and even use it in my car and home systems (where it is of lesser benefit). However, IME the car environment typically has more affect on FR than TA (maybe in rare cases it does not but that has not been my experience).

As for your next quote:



> Ask Erin, or Kirk or Aaron, or Mic or BigRed how many frequencies on the 31 band eq are cut.


Erin and Kirk have both heard my car (Kirk judged a couple of my vehicles). I do value thier opinions but from my discussion with them I don't believe we have any fundamental difference of opinion on EQ (or really any other aspect of car audio). 

Getting back to the real issue... blindly cutting any freqs with an EQ will not get you to sonic nirvana. Use your ears and some type of measurement device to hear/see the affects of what you are doing. If you end up with lots of severe cuts and boosts you likely have an install issue that needs addressing (BTW - I have one now that is being a PIA).

To the OP, if you don't have a working computer for an RTA setup try and find an app for your phone. I have one for my Iphone and at low volumes it works surprisingly well. You will likely notice if you move the phone/measurement device even slightly the response curve will change. Try to take measurements at several locations and look for trends (like 7khz being hot at multiple measurement locations). Typically cut more than boosting. 

Keep in mind that this assumes an independent LR EQ of decent quality. If you don't have that in your current system you are limited to fixing the issues with install (or passive notch filters - not likely something you want to tackle).

AGAIN - GOOD LUCK!

To SQnut specifically,

Dude I am NOT trying to pick on you. I appreciate the fact that you are trying to help the OP. My issue is that your suggestions have been very broad and generalized and could easily lead the OP down a bad path. We have too many people that get into this hobby and quit beacuse they are unhappy with the results and face a torrent of misinformation or don't understand the info that was presented. I think we can both agree some measurements combined with careful listening can help the OP tremendously (it won't fix the problem but he will at least get some idea of *what* needs to be fixed). Enjoy the rest of the weekend.

Charles


----------



## sqnut (Dec 24, 2009)

This is the frequency response measured 1" from the drivers mounted in the door.

Mini Door | Flickr - Photo Sharing!

This is the frequency response, same car, same drivers, same locations except measured at at ear level.

Mini Door | Flickr - Photo Sharing!

How many frickin octaves do you have to cut to get the response somewhere close to that at speaker level? You will never get there, thats how much you have to attenuate. How much will get you close?

Step out of mind sets. Accept the fact that people who judge you would want one competitor less....


----------



## sqnut (Dec 24, 2009)

Sorry,

This is the FR at ear level.

Mini Door 2 | Flickr - Photo Sharing!



> Accept the fact that people who judge you would want one competitor less....


This is out of line on my part.


----------



## Jsracing (Apr 1, 2011)

Sorry for the late response...couldn't find time to test the solutions recommended.

I put a soft blanket on the dash today and the sibilance was very slightly reduced, but not much. It was still irritating. With the blanket in place, the volume is lower, so there's definitely a good amount of reflection going on and amplifying. Sadly, it doesn't seem like the sibilance frequency is as drastically reduced as the overall reflections and volume.
I again tried angling the tweeters, facing each tweeter at the opposing occupant (i.e. driver side tweeter facing passenger and passenger tweeter facing driver), at about a 45 degree angle from horizontal. Again, very minor improvement, but nothing enough to remove the harshness of the sibilance. Cutting the EQ at 6kHz by about 7-8dB (assumed attenuation based on a 12dB max cut and the position of the dial being slightly past halfway point of attenuation) dropped the sibilance a good bit, and cutting 2.2kHz about 3dB helped a small bit.

I use No Doubt / Gwen Stefani songs to test as her songs seem to have the amongst most sibilance of the music I listen to.

I will try swapping polarity on both tweeters later this week and report back. My Morels in my other car with the tweeters in the door facing perpendicular to the door panel surface (i.e. facing the opposite door), don't have irritating sibilance, even at loud volumes. Damn factory tweeter placement! I've noticed most new cars now have the tweeters mounted in the dash facing up toward the windshield at the corners like mine though...wish mfrs designed that differently.


----------



## Jsracing (Apr 1, 2011)

I tried swapping polarity on the tweeters and it didn't help.

I'm wondering if it may be due to my stock HU and/or the LOC. Before I installed my old Nakamichi HU into my other car, I tested it in this car first and recalled the vocals and highs sounded a bit less sharp. I didn't spend much time then to compare the sound and didn't take any time to compare sibilance, but I wonder if either or both of the those may be contributing to a rise in the FR in that range, or possibly even some peaks.


----------



## Mic10is (Aug 20, 2007)

are you unable to cut 8khz?


----------



## Jsracing (Apr 1, 2011)

My EQ goes from 6k to 16k, nothing in between.


----------



## Alrojoca (Oct 5, 2012)

Post to see later


----------

