Tweeter Placement

jay27

Would this location for the tweeter be a good idea? Would there be any issues with this particular placement?

If you can't tell, the tweeter is located just below the woofer when the door is closed and it fires toward the middle of the two front seat head rests. The woofers are in the stock door locations.

MCCLIPSE

This is a very personal decision to make. If it sounds good to you, then it's fine as long as you don't kick it accidentally. If you wanna raise your sound stage as they call it, I would put them up in your upper door panel area or in your A-pillar if you can find a suitable mounting location. It's up to you and your ears to decide where you wanna mount these.

Phillips

No one can tell you whether this is a good position or not unless they have the EXACT same vehicle as you. This would get them in the same ballpark as you, MAYBE. Then there is the little issue with the differences in your ears as far as how you hear, size of your ear canal, preferences as to what sounds good, etc etc.

Only you can decide where to mount your speakers.

arun1963

Where and how you install your tweets, will give you the key to the final door.
I say this based on the assumption, that you have started using the tuning features. If, you want to continue down this road, till you cross over to the dark side , I'd rather that you have this issue, in place now.

1. Tweeters near mids: This setup gives good tonality because, it minimises phase issues between the mids and tweets. It's a setup closer to a point source driver. It's limitation is, that the stage height would be low, or rainbowing at best. You have all the tuning features at hand. You can overcome any issues arising out of placing the mids and tweets further apart.

2. Height: The tweeters are what you want to hear last. The time alignment bit I mentioned in your tuning thread, sets things up to achieve this. Your ears locate height above 2khz. That's about the range where the tweets would be making their presence felt. Hence, hearing this range last and uphigh, it would locate your entire sound higher. Yes, you can raise the stage height by angling your tweets upwards, but not from the floor. That's when you have the rainbow effect. The stage may be higher in the middle but it would be lower at the edges.

However, If they are on the dash and you angle them upwards, thats a different story. Works like a charm. You can also mount them about halfway up your a pillars.

3. Angles: The other thing you want to set, are the angles you aim the tweeters at. Both, on the vertical and horizontal axis. In a car environment, there are tons of reflective surfaces, all the glass the big dash etc. Ideally you would want a tweeter that has a very narrow dispersion. You can then aim this to over come the early reflection points, late reflections are more manageable. Ring radiators and ribbon tweeters have this narrow, almost beam like, dispersion. The normal dome tweeters have a slightly wider dispersion pattern, but it's still fairly focused, so the angles bit would apply.

I would highly recommend, that you do a temp mount on your dash. One that allows you to play with angles as well as location on the dash. Try it at the front edge of the dash, halfway towards your windshield and then at the corners of the windshield. Play with the angles.

Think of it this way. Imagine two beams of light from the centre of your tweeters. By setting the vertical angles, you want the two beams to cross each other, around your rearview mirror, i.e. at the centre and top of your windshield. Of course, in a car environment, these beams will sooner or later reflect off something. It's important that they reflect AFTER they have crossed each other. Late reflections are better than early reflections.

Use the horizontal angles to determine how close to each other they cross. You have to get this bit right to get the seamless sound. I think of this bit as the tweets clicking into sync with each other.

I hope I have'nt confused the hell out of you. Read the post a couple of times if you have to. I tend to ramble at times.

BTW why do you have one screw that sticks out? and what about the missing ones?

jay27

It was a work in progress when I took the pic...

Thanks for the input. So, one of your suggestions is to have the tweeters on the dash in the far corners near the windshield facing upward, reflecting off of the glass itself? Just making sure because that is where my stock tweeters are located.

MacLeod

Thats where mine are in my Accord and they do work pretty well in that spot. The best suggestion is to test several different locations until you find the one you like best.

arun1963

Welcome back bro. While posting last night, I thought this one would pull you in.

arun1963

jay27 wrote: »

It was a work in progress when I took the pic...

Thanks for the input. So, one of your suggestions is to have the tweeters on the dash in the far corners near the windshield facing upward, reflecting off of the glass itself? Just making sure because that is where my stock tweeters are located.

I'm learning to be more carefull with the install bit too.

Yes, play around with several locations and the angles. You can try reflecting them off the windshield or use the angles to have them run parallel to the windshield, till they cross. You will find the loacation and angle that works best for you.

When you play with the angles, you will also need to play with your eq for the 4khz range upwards. If you run them off axis, you would need to boost a bit here. Ofcourse keeping in mind, which frequency is hotter from which side.

Btw, how's the tuning bit doing?

jay27

The tuning is getting better. It's going to take significant time to be decent at it I imagine. I think I need to get a good grasp of what each frequency actually adds or takes away from the sound. That way I can sort of hear my setup and know where to start. For example, if it sounds dull, boost this...or if it sounds bright, cut that. It's a learning process for sure. I know when I don't like a certain sound, but I need to get to where I know exactly which problem areas in the frequency band to address to get where I want to be, if that makes sense to anyone.

arun1963

Don't worry. Everyones been up the same stairs. The attached sheets will help you break down sound into different frequency ranges.

What worked for me, was to listen to music I knew well, one particular range at a time. Eg, I would cut everything and only listen to my mid-bass. 80hz-300hz. This helped me understand what mid bass sounded like in that particular track. Repeated the same for mid-range 300-1khz, upper mids 1-5khz and then the tweets by cutting the sub and the mid driver. Eg a piano plays from like 40hz to 8khz. How does the piano sound in each range? Once you know the sound, it will be easier to identify what you need to correct.

Try this, over like 4-5 tracks. This will give you an idea. Now go back and try to dial tonality (tonally accurate) into each range. Next, listen to two ranges together, eg mid-bass and midrange. Try to blend these and see how a change at one frequency affects the others around it. With sound everything is connected. What you do at 800hz can impact 8khz and the frequencies between. Now add another range......you get the idea.

What you're aiming for, is balanced sound that is free of any stress. No part of the sound is stretched thin or over cooked. The sound is very still. You will probably go thru a phase where the sound jumps around a bit at some frequencies. You need to correct for left/right balance.

Make sure your drivers are always in phase with the TA bit. When you're tuning the mid-bass, your speakers can get out of phase, if you over do the eq bit. If you hear the sound as two seperate halves, you need to revisit TA and your eq. 315, 500hz, 2, 3 and 5khz are some of the frequencies to watch out for. If you run these frequencies out of balance for l/r, you would split your stage.

Make sure you have done the test tones and measuring bit with the spl meter. This will tell you which frequency is hotter on which side and by how much. Eg you may find that 315hz is hotter on the left 6dbs. Read Mac's thread on tuning the sr's. There's a fair bit about this issue in that thread. One more tip here, when youre correcting for this 6db imbalance, dont go like -6 left / 0 right. -3/+3 would be better.

Try to achieve the balance within and across the ranges as well as for left / right, by attenuating rather than boosting. I run my tweets off axis so I have to boost a bit 8khz upwards. Apart from that and 500hz for the right side, everything else is attenuated. Ranging from -2db to -8db.

jay27

Hey, thanks for the advice. I will use the tips and work at it a bit to fix some issues. Thanks!

tk421

excellent sheet arun.

one thing tho.. i think u meant "Your ears locate height above 8khz".
afaik, from scott buwalda's training course, 8khz and above is height.

arun1963

Thanks, I got the sheets from Dan (dirthog). They helped me a fair bit too.

Height cues are a function of HRTF (head related transfer function). It refers to the diffraction of a frequency as it hits your left and right ears. It starts from the 1.25-2khz range upwards. You can google for HRTF if youre technically inclined. Basically, managing ILD and ITD give you your stage width and HRTF gives you the height.http://www.audiojunkies.com/blog/457/12volt-tech-localization-cues-and-how-to-manipulate-imaging

If you're running an eq or processor, you can try this simple exercise. Leaving all other settings the same, attenuate to the max the 1.5-6khz range. What does this do to the stage height? Chances are you will feel that it has fallen a bit.

MacLeod

tk421 wrote: »

excellent sheet arun.

one thing tho.. i think u meant "Your ears locate height above 8khz".
afaik, from scott buwalda's training course, 8khz and above is height.

Im not sure I buy that. Ive met and talked with Scott a few times and I definitely dont claim to know as much as he does, but height is affected by speaker placement. You put your speakers in the kick panels and your height will be in the middle of your dash at best. Ive never, in all the cars Ive listened to, heard one with all the drivers down low have any height at all.

Thats the whole point of placing tweeters up high, to pull the soundstage up.

Pretty much ALL soundstage is affected by speaker placement. If your speakers are all in your door, youre never going to get much more depth than that out of it regardless of tuning.

tk421

ok, stand corrected. guess i'll have to go edit those notes :-(

another theory learned in class was that tweeters should be placed facing each other from the a-pillars. i tried that and found that with the polks, on-axis sounds far better.

so i've placed... (uh.. this note should help jay get an idea what to try)...
so i've place my tweets in the a-pillars and angled each on to the opposing listener. ie- left tweet focused to the right headrest, and vice-versa.

this yeilds a 30degree offset for the closer listener. the 30degree response on the polks are still very very good.

my resulting stage is higher, but more importantly, my tonality improved. especially as i attenuated the tweeters by approx 5db.

MacLeod

I do buy that however, I think I have an easier time tuning my tweeters with them in the dash firing up into the windshield. Maybe not so much tonally but for phasing and time alignment its much easier. When they were in the A pillars time alignment never did work right. It was like they were out of phase but they sounded like that regardless the actual polarity.

arun1963

Great, we have a tuning / install discussion going......will post tonight when I get home.

arun1963

Speaker placement is the key. I'll use my placement and try to explain its impact on my sound.

My mids are in the door, all the way forward, but high up on the door. About 6" below the window. The mids are mounted on two rings of 1/2" mdf. Everything is bolted to the door. The plastic door panel was cut. No way I was hiding these drivers behind a 5x7 stock, panel opening.

The tweets are in a temp mount on the dash, half-way to the windscreen. That is also the highest point on the dash. I know everyone runs the sr tweets cross firing and more on axis. Even I did for about 2 months. But now, I'm running them off axis. The near side tweet is about 70deg off axis and the far side one is about 55deg off axis. When you run them off axis like this there is a very narrow axis range in which they will be in sync with each other. Anything out of this range and the whole thing falls apart.

I have them angled upwards so they would cross each other somewhere under my rear view mirror. The first reflection point would be the driver and passenger windows. All the way forward on the window and about 3/4 of the way up.

My car is a 1 seat setup. I'm the lone occupant 90% of the time. I could be wrong here, but one of my issue with cross firing is, that it's a compromise. No one seat gets the best deal. The sr tweets are pure magic when you get them right for a single position. But that ensures it will never be right for the other seat, no matter how much you tune. Gain something, lose something. Welcome to car audio.

On axis also means that the tweets would cross much closer to you and I feel that brings the image too far out, a bit in your face. Running them off axis lets me take that image deeper into the dash. You can tune for the lost tonality by playing with 5khz+ at your eq. Mac who runs his tweets at the corners of his dash, would'nt have this issue as his speakers are already where he wants his sound from.

When the tweets are off axis the one more off axis will always be weaker at all the high frequencies. The higher you go the weaker it will be. But its curable.

Having the mids high on the door means, I never lack for stage height. It also means I don't get the benefit of cabin gain around the 60hz mark, that the low door mount, near the firewall would give. So while the stage height is great and the image focuses up deep into the dash, with good presence and clarity, I feel like I lack a bit in the low end impact. Gain some, lose some.

When your speakers and placed right and running in phase and you're hearing them in the right sequence, your highs pull your mids and lows up. Like I mentioned, your ear starts locating height above 2khz. Hearing the tweets last with the 2Khz+ frequencies located higher physically, gives you the perception that the entire sound is from that height.

Its kind of like getting your sub and mids in phase. Your ear can't locate sound below 60-70hz, but it can locate the source from your mid bass upwards. So having the sub in phase with the mids tricks the mind into thinking everything is from the front.

To my mind, mounting the tweets higher and the axis you run them at is critical. This is a highly subjective post. Comments are welcome.

arun1963

Stuff I should have mentioned in the post above:

1. Running the tweets off axis is courtesy Patrick Batemans thread on diyma. I had my tweets in temp mount which allowed me to experiment and its working great so far. Even this far off axis they are set at -8db from the hu. A bit laid back but good presence and balance. Good tonality and very smooth.

2. Having the mids in kicks, deep and wide in your footwell would give you a really wide and deep stage. Installed and tuned correctly, this placement can give you width that extends beyond the width of your cabin. With door mounts, like Mac said the width will never be more than the actual distance between them. In both cases the tweets would have to be high, for good stage height. I also feel the kick install would require a lowish crossover point between mids and tweets, some where around 3khz. You dont want to hear too much beyond 3khz, coming from down there. Hearing 2-4khz from the kicks could lower your stage height. Mac can probably comment on this better.

3. If I was to use the sound of rolling thunder as an analogy, to compare the sound of my mids and lower, the attack and pace have good presence and impact. Its the low end rumble where I have decent presence but lack a bit in impact. Lower cabin gain could be one issue (its better to have it and then control it), the other issue could be running a 12" sub off 200watts. In which case this issue may not be placement related. Will have try and hook up a bigger mono amp and check.

One thing is for sure, this hobby can drive you nuts. Thats the bottom line.

tk421

arun1963 wrote:

On axis also means that the tweets would cross much closer to you and I feel that brings the image too far out, a bit in your face.

i can confirm this observation.

and this:

arun1963 wrote:

One thing is for sure, this hobby can drive you nuts. Thats the bottom line.

MacLeod

arun1963 wrote: »

1. Running the tweets off axis is courtesy Patrick Batemans thread on diyma. I had my tweets in temp mount which allowed me to experiment and its working great so far. Even this far off axis they are set at -8db from the hu. A bit laid back but good presence and balance. Good tonality and very smooth.

Depends on the tweeters. The SR tweeters work better directly on axis. You mount them off axis and the right side tweeter will way overpower the left. Different tweeters will sound differently when mounted different ways. Bottom line, try them in all sorts of configurations and mount them the way that sounds best.

2. Having the mids in kicks, deep and wide in your footwell would give you a really wide and deep stage. Installed and tuned correctly, this placement can give you width that extends beyond the width of your cabin. With door mounts, like Mac said the width will never be more than the actual distance between them. In both cases the tweets would have to be high, for good stage height. I also feel the kick install would require a lowish crossover point between mids and tweets, some where around 3khz. You dont want to hear too much beyond 3khz, coming from down there. Hearing 2-4khz from the kicks could lower your stage height. Mac can probably comment on this better.

Again, it depends. If you mount the mids in the sheet metal, off axis, that will give you a wider stage. Mounting them more on axis (like Qforms) will actually give you a pretty narrow stage. Honestly, the door mounting option is the one that usually yields better width as the drivers are actually further out than in any other configuration. However you suffer tonally by having them closer, at oddball angles and being behind a door panel.

Nothing wrong with a high crossover on your mids. Ive had mine as high as 5 KHz and never suffered any loss in height. The tweeters and tuning will take care of the height. Im a firm believer that you want as many octaves coming from a single driver as possible.

arun1963

Tks for the comments.

MacLeod wrote: »

Depends on the tweeters. The SR tweeters work better directly on axis. You mount them off axis and the right side tweeter will way overpower the left. Different tweeters will sound differently when mounted different ways. Bottom line, try them in all sorts of configurations and mount them the way that sounds best.

Both tweets are quite off axis. The pic would give an idea. They are actually more off axis than they look in the pic. With the near side tweets tweets fixed, if the far side tweets angle is out by even a bit, either that side gets hollow highs (far side, too far off axis) or it dominates and just pulls the image to the far side, like you said (now the far side tweet is more on axis than it should be). Between the two is a fine line. Keeping this point is the tough bit. The temp mount is pedestrian....:)

At this point, if I boost the near side and pinch down on the far side tweets I can snap things into place. With mid and tweet x'd at 4khz @ 24db, I set 5 and upwards as follows in db L/R, left being far side:

5khz: -2/-4 balancing top end of mid
8khz: -6/-4
12.5khz: -4/+4
20khz: -6/+4 a 10db difference

The tweets are attenuated -8db at the network from the hu.

Getting this point and keeping it is tough. When they are on the correct axis, they would cross somewhere about where the wool strands cross. Pic is taken from the rear seat. Of course its not exactly like this. The dispersion is basically a very narrow cone.

The sticky on the window is about where the first reflection point would be. So for a 1" base for the cone at the tweet its prob a 4" base by the time it gets to the window. My ears would be about 20-22 inches behind this point

I ran on axis for about 2 months from the same place. Off axis lets me push the image deep into the dash and a bit away from me. The image dimensions are smaller, more realistic. I can selectively boost a bit and get the impact to match the size. One issue may be the clarity and coherence at the two ends of the stage. I think. The other being the ability to do a permanant mount with such a narrow margin of error.

With car audio I have learnt not to make definitive statements. A month from now I may be playing with on axis again, but for now, if I could do a perm install that ensured the right angles I'd do it.





Again, it depends. If you mount the mids in the sheet metal, off axis, that will give you a wider stage.

Yes I read that thread where he talks about cutting the sheet metal to mount the mids. I don't think I would go that far. I have to sell this car some day.

Mounting them more on axis (like Qforms) will actually give you a pretty narrow stage.
Thats what I was talking about. I heard a civic here that had the mids mounted in custom made mdf kicks deep into the floor well. TA was decent and the stage width was nice. Tuning was totally out so no image to speak of. Can't recall if they were on or off axis. I am not too keen on kicks, thanks for settling that.

Honestly, the door mounting option is the one that usually yields better width as the drivers are actually further out than in any other configuration. However you suffer tonally by having them closer, at oddball angles and being behind a door panel. Yes this works well. I cut the plastic door panel so the speakers protrude out of the door panel, but the mounting is secure. The wife nags and says the speakers spoil the visuals in the car. Its not about the visual.

Nothing wrong with a high crossover on your mids. Ive had mine as high as 5 KHz and never suffered any loss in height. The tweeters and tuning will take care of the height. Im a firm believer that you want as many octaves coming from a single driver as possible.

Yes I ran at 5 for a while too, when I was running on axis. I could not tune the thinness out, maybe controlling more frequencies would help here. I kept coming back to 4khz, so eventually decided to stick here. I figure I'm getting the mid to play about 6.5 octaves, from 50 hz upwards.

p.s. no one's allowed to laugh at the clumsy pics......:p lol

arun1963

tk421 wrote: »

i can confirm this observation.

and this:

Are you also trying this?

arun1963

I can never seem to get this done in one post. I also pinch down on 800hz a bit more than normal. helps in managing 8 better. The sound if anything, is very laid back, has a tinge of darkness. Thats the one thing that may drive me back. It's great, but its not perfectly balanced. If I can get this right, I'm through. If this is just an issue of having them so far off axis, then I may have to start rewinding a bit. :rolleyes:

arun1963

well, macs never been wrong. I guess that stands.

Running the tweets that far off axis, you actually get a few things better. Problem is that the rest of the sound can't keep up. So you're out of balance. Running them a bit more on axis now.

To the OP, so now you know how to mount your tweets. Axis and angles are still vital.

arun1963

DSkip wrote: »

Yer steerin' wheels on the wrong side bud.

Yeah thats courtesy the Brits....lol

jay27

A quick noob question regarding crossing over the mid:

I understand that crossing the tweeter too low can blow it. If you attempt to cross over the mid too high, I assume this would not damage the midbass speaker? Would there just be a natural roll off at some point? For example, if you crossed a mid at 8k, would the speaker just not produce sound that high or would it sound terrible in trying to do so?

arun1963

Crossing the tweets low (under3 khz, appx), would make your 2-4khz range very bright. Overall, the sound would tell you the tweets are overly bright. Yes, if you went a bit lower, you could damage your tweeter.

Most mids start rolling off around 5-6 khz. With the mids and tweets, its all about how you merge them. You want to use your xover point to merge the two ranges. The highs should just sound like a natural extension of the mids and upper mids. You don't want to hear them as two separate sounds.

3.5-5khz is a common range most people use. Try it. See whats sounds best to you. You need to merge the mids and tweets over a slightly wider frequency range than your sub and mids. At each xover point, play around with the slopes on both drivers. This controls how far above or below the x point, the drivers play. It sets up the range over which you're merging the two drivers.

jay27

But you can't damage the midbass speakers by playing them too high, correct??

MacLeod

Right.

arun1963

Yes you wont blow you mid by running it at 8khz. But if you crossed mid and tweet at 8khz you would have a dip somewhere in the 5-7 khz range depending on the slopes you're using.

To get the right balance around the xover point, slopes are one thing you have to manage and the other is L/R eq of frequencies in this range. Above say 2khz, balancing frequencies for left / right intesity is more important than time alignment. But you still have to TA your tweets.