"rSD comp tweeter" A-pillar mounting question

[eyesofra]

ok ...will wait for ur post then...thanks man

[444 FED]

path length difference...so thats the problem in my install?
what can i do bdups ?
would it do any good if i mount the tweet on the pillar where it gives me an equal length as to where the mid is ??

no pld is refering to driver distanace from each other from L to R. Like for instance a tweeter mounted on the driver side of an a-pillar will be say 20" away from the drivers head, while the passenger side tweeter will be mounted lets say 36" away from the drivers head. This causes a number of problems, and TA is only bandid so IMO PLD are critical. Then once you sepearte your tweeters from mids you have 4 different PLD instead of two making it very hetic. The best installs I have heard have been the ones that minimize PLD plain and simple, ever time they win.

So basically what you want for the best staging and imaging is find the place in your car where you can get the most depth, width, least amount of reflections, hieght, and minizied PLD. The best place for all these factors is in the kicks. The kicks are the best spot for all of those factors other then stage hieght, which can be over come w/ angles and EQ.

I figured out TA before your post dueto another one, then you posted the definition of PLD and now this makes more sense. LOL

Anyway, I believe you are over complicating this PLD issue (BTW I don't just limit PLD problems to left to right, I also include them for each individual driver. Now, if both the mid and tweet for the same side are equaldistant to the listener, that ELIMINATES ANY PLD issues (between Mid and tweet) right there, which leaves you with the same left to right PLD issues you still have with Kicks anyway.
Like I mentioned before the dash or lower A-pillar mounting location works better with a windsheild that is pushed far forward to get the tweeters as equadistant as possible, but have has some succes in cars that didn't have the high angle windsheild. Also when the tweeter is placed in the very corner the windsheild and dash can start to act as wave guides and help the sound disperse better than if they were just placed in the middle of a flat panel. Think horns.
We both agree TA is a band-aid, I've never liked it, since I strive to have the same stage for both side, not just one.

There's also something else you are forgeting when these tweeters are angle on and off-axis listening. The more on-axis you are with the driver the "louder" it will be, or more accuratly more projected, whefre as off-axis is usually softer, so the levels of each side or tweeter as we are discussing, will seem the same, and help the psychoacoustics work in your favour.

I've done this quite a few times now and the result is amazing, I have never been able to get the staging using Kicks I can with the lower A-pillar mounted tweets. No matter how much processing or equalization was done any kick mounted speaker I listened to always seemed to have the stage floor about mid way up the dash at highest, where as in my car it is dash top level, with the singers seeming to hover above that, and at many points accross the stage.

[bdubs767]

Anyway, I believe you are over complicating this PLD issue (BTW I don't just limit PLD problems to left to right, I also include them for each individual driver. Now, if both the mid and tweet for the same side are equaldistant to the listener, that ELIMINATES ANY PLD issues (between Mid and tweet) right there, which leaves you with the same left to right PLD issues you still have with Kicks anyway.

LOL, have you ever measure this? No place in any car I have ever seen will at any spot offer equal PLD, w/o pushing back the seats quite a few inches. The kicks in every car offer the least difference from the listener from R to L

Like I mentioned before the dash or lower A-pillar mounting location works better with a windsheild that is pushed far forward to get the tweeters as equadistant as possible, but have has some succes in cars that didn't have the high angle windsheild. Also when the tweeter is placed in the very corner the windsheild and dash can start to act as wave guides and help the sound disperse better than if they were just placed in the middle of a flat panel. Think horns.

This still wont offer a PLD and depth that kicks do.

We both agree TA is a band-aid, I've never liked it, since I strive to have the same stage for both side, not just one.

What? TA just delays the signal to the speaker in milli seconds allowing for one speaker to play "slower" then another. This allows the signal from each in theroy to arrive at the listener at the same time. So I have no idea what you are referring to.

There's also something else you are forgeting when these tweeters are angle on and off-axis listening. The more on-axis you are with the driver the "louder" it will be, or more accuratly more projected, whefre as off-axis is usually softer, so the levels of each side or tweeter as we are discussing, will seem the same, and help the psychoacoustics work in your favour.

okay and why cant you do this w/ tweeters in kicks? I've done it before, and was the best tonal sytem I have ever had. Yet it was a one seat wonder every where else in the car sounded like shit. I would be more worried w/ off axis performace of mids then tweeter fyi. Tweeters tend to have much better off axis performance then mids. The larger the driver the worse off axis performance it will have.

I've done this quite a few times now and the result is amazing, I have never been able to get the staging using Kicks I can with the lower A-pillar mounted tweets. No matter how much processing or equalization was done any kick mounted speaker I listened to always seemed to have the stage floor about mid way up the dash at highest, where as in my car it is dash top level, with the singers seeming to hover above that, and at many points accross the stage.

well you value stage height over depth, width, and, maximizing lowest PLD. I have been able to raise the stage height w/ these and had great results plain and simple.

[444 FED]

Anyway, I believe you are over complicating this PLD issue (BTW I don't just limit PLD problems to left to right, I also include them for each individual driver. Now, if both the mid and tweet for the same side are equaldistant to the listener, that ELIMINATES ANY PLD issues (between Mid and tweet) right there, which leaves you with the same left to right PLD issues you still have with Kicks anyway.

LOL, have you ever measure this? No place in any car I have ever seen will at any spot offer equal PLD, w/o pushing back the seats quite a few inches. The kicks in every car offer the least difference from the listener from R to L

Yep, I have, and maybe because I like my seat back farther than some it works. I lik eto have my leg straight when I push the clutch in (in a manual vehicle), and have noticed that the difference at the base of the A-pillar to what is betwene teh kicks is about the same.

Like I mentioned before the dash or lower A-pillar mounting location works better with a windsheild that is pushed far forward to get the tweeters as equadistant as possible, but have has some succes in cars that didn't have the high angle windsheild. Also when the tweeter is placed in the very corner the windsheild and dash can start to act as wave guides and help the sound disperse better than if they were just placed in the middle of a flat panel. Think horns.

This still wont offer a PLD and depth that kicks do.

We both agree TA is a band-aid, I've never liked it, since I strive to have the same stage for both side, not just one.

What? TA just delays the signal to the speaker in milli seconds allowing for one speaker to play "slower" then another. This allows the signal from each in theroy to arrive at the listener at the same time. So I have no idea what you are referring to.

TA just delays the signal to a speaker as you said, which makes the listening postion only ideal for one seat not all (both). Basically I was just saying that we both dislike the use of TA. It might be ok, if pairs of speakers were delayed equally, like say the tweeters were dleayed in comparison to the mids and the mids were delayed in comparison to the subs, to TA the entore frequency range, which is somethjintg I have thought about, but have never been able to afford a processor that was capable of doing this. I do have a Clarion 955 MC that has this capabilty though, but I'd have to give up my DVD capabilities I have now.

There's also something else you are forgeting when these tweeters are angle on and off-axis listening. The more on-axis you are with the driver the "louder" it will be, or more accuratly more projected, whefre as off-axis is usually softer, so the levels of each side or tweeter as we are discussing, will seem the same, and help the psychoacoustics work in your favour.

okay and why cant you do this w/ tweeters in kicks? I've done it before, and was the best tonal sytem I have ever had. Yet it was a one seat wonder every where else in the car sounded like shit. I would be more worried w/ off axis performace of mids then tweeter fyi. Tweeters tend to have much better off axis performance then mids. The larger the driver the worse off axis performance it will have.

Well I don't know what to tell you on this one, I have found the opposite to what you describe that tweeter off-axis is much worse than mid or sub off-axis, the fact that lower frequancies are omni-directional, or the closer you get to the lower frequencies, the less directional they are.

I've done this quite a few times now and the result is amazing, I have never been able to get the staging using Kicks I can with the lower A-pillar mounted tweets. No matter how much processing or equalization was done any kick mounted speaker I listened to always seemed to have the stage floor about mid way up the dash at highest, where as in my car it is dash top level, with the singers seeming to hover above that, and at many points accross the stage.

well you value stage height over depth, width, and, maximizing lowest PLD. I have been able to raise the stage height w/ these and had great results plain and simple.

My stage is deep and wide, with my tweeters mounted at the base of the A-pillars, much better than many other systems, overall. I have had one system that had slightly wider stage, but it also had speakers in the dash, mids mounted differently.

Yes, I'd like to get the stage a bit deeper, but having it seem on the hood on most passages is good enough for me. Width is about the only thing I'd like a bit wider, but having my current stage extend just beyond the outer A-pillars seems pretty good to me, especially since my passive crossovers are junk that I found in a parts bin and the mids and tweeters are from two different component sets. *shrug*

The only system that I have ever heard with a better width and depth was a system that utilized Horns, USD IIRC, but the staging although better than conventional speakers mounted in the kicks was still a bit low for me.

I've also seen this trend for a long time in car audio competition. Think back to many high end systems in IASCA, most of them had toned down tweeters placed in the A-pillars or top of the dash to raise the stage level, then these became the main tweeters, because there were phase issues, when running tweeters like this in some cases, and more expense when it wasn't needed.

I will say that not all cars will be able to use this design, but most will, especially late model vehciles where the windsheild is pushed far forward.

It does hurt to try temproraoly mounting tweeters in a location like this and seeing if it works for the vehicle, just takes some time.

[bdubs767]

well clearly neither us will agree...simply put you prefer a high sound stage compared to a wide, deep, and maximixed PLD sound stage.

Dont jump to over the bridge either I was refering to mid ranges not subs....

[VW337]

RA-

In your situation you have several issues, firstly the RSd comps are designed to be mounted with less than 6 inches between tweet and mid. The XO accounts for Phasing and EQ variations. Furthermore with that said the Phase will be effected if the drivers are not mounted on a common plane as that is the way they are again designed (I don't think anybody will question my knowledge of the design of these drivers).


I would guess you have a big hole in your response at the moment, and
in your situation the first thing I could suggest is if the tweets are wired 180 out of phase already, try doing the same with the sub, or flip the tweets back to normal and then flip the mids. Next if you still have an issue I would suggest adding a 2 ohm 10 watt resistor inline with the tweets just to see if this helps if so you can play with 2-4-8 ohm options.





Back to a previous mention of phase vs. polarity...........yes if you flip the input polarity of a driver it is technically "polarity" but what mechanically happens? Well I for one would vote that the phasing is shifted 180 out of phase from the input signal.

[smgreen20]

Take notice that not everyone has the same taste in sound as well. What might sound deep and wide to one wont w/the other. Up until my surrent truck, I've always used kicks and get the same probs having my soundstage at dash level and that's to low for my likes. No amount of eqing has fiexed that for me. In a car it might work out but in a truck there's to much heigth to make up. A friend of mine thinks my staging/imaging is awsome, to me it sounds like shit. Eqs where made to "equlize" the freq spectrum. People have found all sorts of other ways to use eqs other then what they were intended for. Speaker placement is paramount no matter what speaker is where.

[444 FED]

well clearly neither us will agree...simply put you prefer a high sound stage compared to a wide, deep, and maximixed PLD sound stage.

Dont jump to over the bridge either I was refering to mid ranges not subs....

How many times do I have to say that my stage IS wide AND deep along with HIGH?

[smgreen20]

It's getting heated. Remember, that's why I said one has different taste or perception than the other. I'm in between you two on your thoughts. For me, it's speaker placement no matter how far apart anything is from another, PERIOD! Myfriend who has a pickier ear than myself thinks that my soundstage is supurb. Then again, he's sitting in the passenger side.

[HoseHead]

Back to a previous mention of phase vs. polarity...........yes if you flip the input polarity of a driver it is technically "polarity" but what mechanically happens? Well I for one would vote that the phasing is shifted 180 out of phase from the input signal.

My understanding:

Reversing polarity at the speaker would force the speaker cone to move in the wrong direction when signal current hits the coil. A traditional speaker cone is designed to deflect outward from the coil (or inwards towards the listener) to reproduce sound.

Phase shifting through a processor delays the time it takes the selected frequencies from getting to the speaker coils. The speaker still deflects in the correct direction, but now at the "processed" time.

Phase shifting is usually applied to lower frequencies. They take longer to produce and depending on the environment may not get to the listener with the rest of the sound, causing perceived distortion for the listener.

Or did I miss that day in class? Comments.

HH

[smgreen20]

Here's a pic of an SQ competater in a full size truck. At least for me, I rest my case. Tweeters in the middle of the A pillar.

http://www.sounddomain.com/ubbthreads.p ... 11/fpart/8

[eyesofra]

RA-

I would guess you have a big hole in your response at the moment, and
in your situation the first thing I could suggest is if the tweets are wired 180 out of phase already, try doing the same with the sub, or flip the tweets back to normal and then flip the mids. Next if you still have an issue I would suggest adding a 2 ohm 10 watt resistor inline with the tweets just to see if this helps if so you can play with 2-4-8 ohm options.

that's rite errin, i do have a big hole in the respsonse and running out of ideas i've been trying to fill that up playing around with x-over points of my sub and comps. It works but not to what i'm trying to get...good imaging..

I'll try flipping the mids and subs phasing today as u've mentioned.
But can u explain on what a 2-4-8ohms options is.
something like tuning with L-pads ?

and what happens if i mount the tweets on the same plane of the mid ...on the door panel ? what kindda outcome would that be on phasing and imaging

[mr tibbs]

I actually had my initial setup like that in my current car. Personally I hated it, it drove me nuts. I had the tweets in an angle mount aimed up at my dome light. No matter what I did it sounded like crap, sooooo I moved the tweets up into the sail panels (the little cover that covers up the mirror bolt). This did wonders for me. I was able to do so much more with my soundstage, it just seemed to open everything up. I'm sure my sysem still needs some tuning, but to my untrained ear it's not too bad. Just my .02 cents.

[VW337]

RA-

I would guess you have a big hole in your response at the moment, and
in your situation the first thing I could suggest is if the tweets are wired 180 out of phase already, try doing the same with the sub, or flip the tweets back to normal and then flip the mids. Next if you still have an issue I would suggest adding a 2 ohm 10 watt resistor inline with the tweets just to see if this helps if so you can play with 2-4-8 ohm options.

that's rite errin, i do have a big hole in the respsonse and running out of ideas i've been trying to fill that up playing around with x-over points of my sub and comps. It works but not to what i'm trying to get...good imaging..

I'll try flipping the mids and subs phasing today as u've mentioned.
But can u explain on what a 2-4-8ohms options is.
something like tuning with L-pads ?

and what happens if i mount the tweets on the same plane of the mid ...on the door panel ? what kindda outcome would that be on phasing and imaging

In regard to same plane think of it as a wall or counter top........no matter where you place two speakers on that surface (given that it is a traditional flat surface) the face of both drivers are level with each other, this is what is meant by same plane. Now the closer the drivers are to each ohter on this plane the better their inherent response along with the XO design will complement each other. This is because when they are tuned they are mounted in a flat sheet (same plane) and are ~3 inches apart, so the XO is by nature designed to flatten any response issues in this configuration.


No on to the 2-4-8 ohm issue, since a tweeter is now in a car and you have glass and othe hard smooth reflective surfaces your tweeter could in reality be playing 3-6db (or more) higher in certain frequencies than your other speakers. If you wire a 2 ohm resistor inline this will lower the drivers output a little and also delay the signal just a smidgen. Now if this helps but doesn't do the trick swap the resistor for a 4 or 8 ohm, you could use a potentiometer in this matter but it may be a bit difficult to keep it in a fixed position once you find a sweet spot.

[VW337]

Back to a previous mention of phase vs. polarity...........yes if you flip the input polarity of a driver it is technically "polarity" but what mechanically happens? Well I for one would vote that the phasing is shifted 180 out of phase from the input signal.

My understanding:

Reversing polarity at the speaker would force the speaker cone to move in the wrong direction when signal current hits the coil. A traditional speaker cone is designed to deflect outward from the coil (or inwards towards the listener) to reproduce sound.

Phase shifting through a processor delays the time it takes the selected frequencies from getting to the speaker coils. The speaker still deflects in the correct direction, but now at the "processed" time.

Phase shifting is usually applied to lower frequencies. They take longer to produce and depending on the environment may not get to the listener with the rest of the sound, causing perceived distortion for the listener.

Or did I miss that day in class? Comments.

HH

HH- in the audio world TA and Phasing are intertwined, as well as Phasing and polarity. If you are talking reversed polarity it is equal to 180 out of phase. Now if you are talking time delay, you are delaying the signal in tiny amounts in turn shifting the speaker phase by minor amounts such as a 5 degree shift. However at some point the time variations will become very audible and if you have to shift it so far to get it to sound right you may be better starting with reversed polarity or 180 out of phase, since at this point the speaker is playing in the correct time domain however it is a direct opposite of the intended signal.

I know the discussion can go on forever but understand you are right and you are wrong yes "polarity" is the term that should be used but polarity is not the intent when switching the wires it is intended to switch the phase without effecting the time domain.

[smgreen20]

BUT! If you put a resistor (2,4, or 8 ohm) wouldn't that change the xover point?????

[bdubs767]

all the more reason to go active


JK had to throw the jab out there.

[eyesofra]

thanks for that errin,
I've tried playing around with the tweets , placing it on the a-pillar - top,centre ,down on the dash but nothing seem to fill the gab in the response.

Also tried with the phase adjustments but no significant diferrence or maybe i'm just not hearing it.

Yesterday i placed the tweets deep on the kick leaving the mids at the factory location ( as in the diagram ) .
This seems to fill in the gab !
Sounds much tighter and i dont actually feel the tweets being deep down on the kicks.
The vocals centres much better now though it still biased a little.

The tweets and the mids are nearlly on the same plane ...the tweets are around an inch ( max) forward comparing to the mids.
The distance between them would be around 5-7 inches.

Now, i've angled the tweets around 45degrees towards the cabin.
Will this cause phase issues or should i just leave it horizontal 0 degrees ?
What can i do to improve the overall quality of the sound in this type of install ??

thanks again

[dragonplayboy]

I'm also curious about this, I was planning to do the tweets (of the RDS 6.5cs) in the a pillars but if errin reccommends kick locale, I can give that a shot. I'd really rather not build kicks but if I gotta, I gotta. Ra, can you describe the "gap" that was missing using the a-pillars? did you try the tweets with both polaritys? Errin, does the above diagram look like a viable option? I'd really love to avoid building kicks for my wife's car. Also, if I do go thru with it, should I seal off the woofer or let it run IB down in a kickpanel?

thx!

[bdubs767]

I'm also curious about this, I was planning to do the tweets (of the RDS 6.5cs) in the a pillars but if errin reccommends kick locale, I can give that a shot. I'd really rather not build kicks but if I gotta, I gotta. Ra, can you describe the "gap" that was missing using the a-pillars? did you try the tweets with both polaritys? Errin, does the above diagram look like a viable option? I'd really love to avoid building kicks for my wife's car. Also, if I do go thru with it, should I seal off the woofer or let it run IB down in a kickpanel?

thx!

no seal IB only

[dragonplayboy]

thx bdubs! would it be better to angle each set of woof/tweet at the driver or at the opposite passenger? or straight in? or a combo of each? an important consideration would be that my wife is 5'2" and she sits about halfway up, I sit with the seat all the way back. (I'm about 5'11")

[bdubs767]

thx bdubs! would it be better to angle each set of woof/tweet at the driver or at the opposite passenger? or straight in? or a combo of each? an important consideration would be that my wife is 5'2" and she sits about halfway up, I sit with the seat all the way back. (I'm about 5'11")

wife who cares...

play around w/ angles

[dragonplayboy]

she drives the car 80% of the time and I spent all the money on the crap, I care

[eyesofra]

[quote=" Ra, can you describe the "gap" that was missing using the a-pillars? did you try the tweets with both polaritys? ?

thx![/quote]

there was like a " hole " in the music by placing the tweets on dash and on the pillar. I meant this as the "gab".
yeah i did all sort of phase tricks with most of the drivers...
reversing both the tweets, reversing the mids, reversing both drivers at one side, reversing just the tweets at the deivers side , played around with the subs phasing too....

but for my ears i just couldnt get it to sound any better than the initial setup...

and with all 3 pedals down there, i just dont have the space for a dedicated custom kick panel.

well lets wait and see what the "gurus" got to say on these type install.....

[Phoenixcolt]

So tweeter placement down in the door will work very well?

That is pretty sweet. I was going to mount mine in the stock dash locations when I finally get to install all my ish but I kinda like the way you're setting it up better. I feel like that would allow for better imaging since the sound won't be flying right off the front windshield...but then again if I mount in the dash, I also have a Clarion 955 MC which will allow me to time align the tweets and mids independently though I will have to go active as a result....hmmm...if this setup in the illustration works well, I may revise my own plans, would be a lot less trouble.

Hope someone could offer a little more info on setting up like this.