Sound Stage Q's

[solacedagony]

I have two sound stage questions based on my ride home from school tonight.

1.) I noticed that my (vertical) sound stage is about a foot too low. What can I do to bring the sound stage up to my head level? What methods are used for moving a sound stage vertically?

2.) What effect will sound deadening the car (more specifically, doors) have on the sound stage?

Finally, I just had a quick question on ports. My box will be wedge-shaped, so the port will be 11" at the bottom and 6" at the top. Can I use the average method with that to get a workable answer that I can stick into WinISD? ( (11+6)/2=8.5" )

[sqkev]

I think it would help if you answer a few questions.
-what drivers are you using? locations? crossover points/slopes?

sound deadening - the purpose of it is mainly to keep block out the road noises (ambient noise) and help some of the resonances within the vehicle. If you have your drivers in the doors and you deaden the doors to a certain degree, you might find that some of the panel resonances might be lower. Thus, it helps to eleviate localization of the drivers and your soundstage will become a bit more coherent.

[alphakenny1]

Originally Posted by sqkev

I think it would help if you answer a few questions.
-what drivers are you using? locations? crossover points/slopes?

x2

[bobditts]

to answer the port question, as long as the port volume matches what it should be if it were square, then you should be fine. Im not sure what it will do to the sound though.

[thadman]

Ive heard (something clarify this...i could just be speaking out of my ass) but humans notice very little vertical change in stage height below 1000hz and distinguish very little horizontal change once we get down to <250hz.

My suggestion to you (without knowing your drivers...this is a generality) is to mount your tweeter as high as possible (within reason...dont mount on the ceiling or nething crazy) and cross as low as possible.

[solacedagony]

My setup is in my signature. I have my tweeters right now zip tied high up on my A-pillars because I was playing with aiming. The tweeters are quite near the ceiling of the car since it's a very small cab. I have them both just above ear level.

I'm not sure what the crossover points and slopes are on it. I even emailed Bravox and they never got back to me. Might have to call them to find them out.

Thanks for the replies so far guys.

[Chaos]

Dampening your doors may help improve imaging, just as sqkev suggests, but height of the soundstage could be most dramatically affected by speaker position. You just have to experiement. If the tweeters are already high on the pillars but the SS is low, I might try lowering them to just above the dash and aiming them up & in towards the rearview mirror. The off-axis response may create an entirely different perceived SS height...also, try flipping the phase on the tweeters...

[thadman]

You've got a cd8454 in your sig, why not go active with that?

The crossover is probably pretty high since its a 5.25 component set

[solacedagony]

I didn't have a 4 channel amp to run active with (plus I haven't run active yet), so I wanted to experiment with just running T/A on L/R and still use the passive crossover. I should be receiving my 4-channel in the mail very soon, so I can mess around with going fully active then.
So getting the sound stage high may require just a bunch of experimenting with weird positions and whatnot? The only reason I tried to keep the tweeters high was since it was such a small cab, I felt that the tweeters would get blocked too much down low.
I also have a set of Neo3s that I can try out once I get the amp.

[bobditts]

your tweeters are up high right now but where are they aiming?

[GMo]

Originally Posted by thadman

Ive heard (something clarify this...i could just be speaking out of my ass) but humans notice very little vertical change in stage height below 1000hz and distinguish very little horizontal change once we get down to <250hz.

My suggestion to you (without knowing your drivers...this is a generality) is to mount your tweeter as high as possible (within reason...dont mount on the ceiling or nething crazy) and cross as low as possible.

Almost right on the money

Vertical cues affect us with freq's approx > 1500hz
Horizontal cues affect us with freq's approx <1500hz
1000hz to 2000hz is a bandwidth where cues aren't as prevalent.

Humans aren't sensitive to horizontal cues under approx 250hz, even though they exist.

I'd say either the tweeters need to be aimed higher or brought up to raise the stage, as was said.

[solacedagony]

Right now, the tweeters are aimed at my ears, but when I duck my head down, it seems like the stage comes together much more.
http://good-times.webshots.com/album/551843612RKnjCy
I don't have any pics of the tweeters, but at least you get an idea of my truck.

[bobditts]

try aiming the tweeters at the center of the windshield.

[solacedagony]

Alright, I'll give it a shot.

[sqkev]

lots of height info, as suggested above are coming from both of your mids and tweeters.
If your tweeter is crossed way too high, most of the vocal would be coming from your mids. If your tweeters can take it, cross them a bit lower and try reposition them.
Of course, YMMV.

[solacedagony]

YMMV?

[bobditts]

You try aiming them at the center of the glass yet? After you play with that, you can try aiming the left tweet towards the right pillar but still on the glass, and the right tweeter in the same spot but the mirror image. Basically so the wave cross at the center of the glass but a few inches inward. Usually aiming ad the exact center provides a deeper sound stage. Id also try moving the tweets down the pillar to about 12" off the dash. If you have them more towards the headliner, that could cause some problems.

[solacedagony]

Not going to be able to play with it until tomorrow morning, but I got some 2 sided tape, so I'll use that to stick them places. 1st thing I'll try is that center of the glass thing. Should they by sitting on my dash when I try that or on the A-pillars?

[bobditts]

on the a pillars about 12" up

[bobditts]

hows the testing coming along?

[solacedagony]

Beside the immense of amount of school work I've been getting, I started a new sealed box for the sub, so I haven't gotten a chance to test. Mostly finished the box over the weekend (need to buy a new router :-X). I'll be putting in the new 4-channel amp so that's going to require a new amp rack. So after the amp rack, I'll be pulling the tweeter speaker wires out so I can test them in a bunch of spots.
Thanks for checking up on me!

[invecs]

Try to flatten response on the top end by speaker placement and aiming...if it doesn't help, try to eq it out. Check out the speaker levels also. From my experience, imaging and staging are very much related to having good phase and a flat response.

[solacedagony]

Yea, I'll be playing with it as soon as I get the other stuff done. I started looking through some software for measurements. When I can find someone's laptop to steal, I have a cheap mic that I do some minor testing with, just to get myself in the ballpark.

[Ozziefudd]

Originally Posted by solacedagony

My setup is in my signature. I have my tweeters right now zip tied high up on my A-pillars because I was playing with aiming. The tweeters are quite near the ceiling of the car since it's a very small cab. I have them both just above ear level.

I'm not sure what the crossover points and slopes are on it. I even emailed Bravox and they never got back to me. Might have to call them to find them out.

Thanks for the replies so far guys.

The passenger cabin of a car or truck is less than the idea place for speaker placement. Obviously your tweeters being zip tied is a less than idea situation but I would suggest you get them away from the ceiling. A pillar mounts for tweeters are great but you also need to be concerned with your path length so try putting them as far down on the A pillars as you can with out getting them to the point you would get resonances off any instrument panel hump. This will help to equalized the path length between the tweeters so you dont have one say 18 inches and another at 36 inches which would require you to add more delay. Once you do that then you do need to do some EQ work. As stated in a previous post the human ear and brain can't/doesnt translate lower frequences on the horizontal, you have to get around 9k and up for most individuals to notice heighth. So play around with the 9k and up and with the slope until you find what sounds at eye level for you. Your tweeters will not have to be at eye level.

[subwoofery]

It's been said earlier but not sure you've noticed:
Change the polarity of one of the tweeter (driver's side).
or
Change the polarity of both tweeters relative to the mids.

Decide which sounds best.

Have learned a lot these past couple of weeks.

Hope that helps,
Kelvin