Sound Imaging
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From: Calgary, Alberta, Canada
Sound Imaging
I have been out of the sound game for a while (3 or4 years) but I still have some fabulous equipment. My while designing the system for my truck is Imaging??? "Thunder" has posted several reply's on putting speakers in the kick panels to get better imaging. "Thunder" can you help me with the theory behind this?
I'm certainly NOT looking to flame anyone but I need to learn how this helps imaging. Years ago a buddy of mine said, "Your ears are in your head, not your feet". What is the benifit to this? Is it the distance to your head while seated in the Drivers seat? I have alway mounted and aimed the mid/high seperates closest to the head level while keeping the driver and tweeter close so as not to 'seperate' the voices. While I was looking at my truck I thought a 6 1/2" driver angled up in the front door with a tweeter in the plastic panel where the side mirrors protuded would work effectively.
Thanx in advance
Bruce
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'97 F-150 Lariat,4.6, S/C, 4X4, SB, 17"wheels, no mods.
I'm certainly NOT looking to flame anyone but I need to learn how this helps imaging. Years ago a buddy of mine said, "Your ears are in your head, not your feet". What is the benifit to this? Is it the distance to your head while seated in the Drivers seat? I have alway mounted and aimed the mid/high seperates closest to the head level while keeping the driver and tweeter close so as not to 'seperate' the voices. While I was looking at my truck I thought a 6 1/2" driver angled up in the front door with a tweeter in the plastic panel where the side mirrors protuded would work effectively.
Thanx in advance
Bruce
------------------
'97 F-150 Lariat,4.6, S/C, 4X4, SB, 17"wheels, no mods.
Senior Member
Joined: Jan 2000
Posts: 126
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Bruce, your question requires a pretty long answer. Sorry to everyone in advance for the term paper that follows...
The reason behind putting speakers on the kickpanels has to do with getting sound from the left and the right speakers to arrive at your ears at the same time.
You could address the problem by either using time alignment equipment (digital delays) or by optimizing the pathlength as the kickpanel placement tries to achieve.
Using time alignment presents additional problems, though. By introducing a delay to the speakers nearer you (to make the signals arrive at the same time as the sound from the speakers farthest you) you get better sound at your listening position and only at your listening position while it exacerbates the problem for the passenger. It's also more expensive...you would be needing a fully active setup (a separate channel of amplification per driver), active crossovers, as well as a digital delay processor. Going this route gives rise to the possibility of more things going wrong as you have more equipment.
The kickpanel configuration tries to solve the problem of unequal pathlengths by minimizing the pathlength difference. Putting the speakers in the dash or doors results in a relatively large path length difference between the left speakers and your ears and the right speakers and your ears as a percentage to total length (between either speaker and your ear). To give you a better picture, assume that AB is the lenght between the left speaker and your ear. AC is the length between the right speaker and your ear. The difference is AB-AC. You are trying to minimize both (AB-AC)/AB and (AB-AC)/AC.
A kickpanel install minimizes pathlength difference by increasing the total distance of speakers to your ears, therby lowering the difference in distance. (You increase AB without increasing AC--which is longer--so much so the difference between AB and AC gets smaller).
To reply to your friend's comment, try this experiment in your den or other suitable room at home: Get two smallish bookshelf speakers and place them in the approximate places where the kickpanel mounted speakers would go. Make them face each other as they would in your car. Play some music and sit right in the middle of the two speakers, a couple of feet or so back. Close your eyes and listen. Music sounds like it's coming off the floor, right? Now angle the speakers so they face you. Close your eyes and listen again. Not too shabby, eh? Tell your fried you don't have ears near your stomach or chest either but car speakers are placed in that general area too
(The experiment above, by the way, is meant to show that proper speaker placement in a kickpanel installation can work. It wasn't meant to prove the pathlength difference part of the question, although you could also prove it using the same equipment. You just need stools or something similar to place speaker on to approximate chest level mounting height and you have to sit closer to the left speaker.)
The drawback I've noticed in kickpanel mounting is the relatively low position of the soundstage (after all, everything is a compromise...) You would want the sound stage to be ideally centered *around* eye level. The workaround I've found to this would be to get additional tweeters, preferably the same ones you use in the kickpanel, and mount them far deep in the dash corners. You would need a separate amp, yes. The trick is to attenuate the dash tweeters enough so that they only work as a "fill" effectively raising your soundstage without drawing any attention to themselves.
In an Expedition/F150 setup, I haven't found a better arrangement than getting a good three way system, mounting the woofers in the stock door location (8-10 in.) mids and tweets in the kickpanels, extra tweets in the dash. Took a lot of trial and error, to-ing and fro-ing, but those are the results of more than a year of on and off experimentation. I guess the same would apply for most vehicles, though I haven't tried so I can't say for sure. Logically, it should be applicable.
Then again, you can get a McLaren F1 that has the driver right smack in the middle of the cabin, then you can mount everything on the dash and not have path length difference problems. But that car costs around a million bucks. One of my clients just bought one. (I'm an investment banker.)
How's that?
------------------
Thunder
rainmaker@attglobal.net
Black 97 Expedition EB 5.4L 4WD
Mods: Lightning Wheels, Pirelli Scorpion Zero 285/55VR18, K&N Gen II Kit, JET Chip
Brembo 14" disc brake kit coming right up!!!And hopefully a Lightning engine too!!!
Audio: McIntosh MX406, McIntosh MCD4000, Zapco SX-SL, Zapco EQ30, Genesis Monoblocks (3), Genesis Dual Mono, Dynaudio System 340, Dynaudio System 220, JL Audio Stealthbox
[This message has been edited by Thunder (edited 01-28-2000).]
The reason behind putting speakers on the kickpanels has to do with getting sound from the left and the right speakers to arrive at your ears at the same time.
You could address the problem by either using time alignment equipment (digital delays) or by optimizing the pathlength as the kickpanel placement tries to achieve.
Using time alignment presents additional problems, though. By introducing a delay to the speakers nearer you (to make the signals arrive at the same time as the sound from the speakers farthest you) you get better sound at your listening position and only at your listening position while it exacerbates the problem for the passenger. It's also more expensive...you would be needing a fully active setup (a separate channel of amplification per driver), active crossovers, as well as a digital delay processor. Going this route gives rise to the possibility of more things going wrong as you have more equipment.
The kickpanel configuration tries to solve the problem of unequal pathlengths by minimizing the pathlength difference. Putting the speakers in the dash or doors results in a relatively large path length difference between the left speakers and your ears and the right speakers and your ears as a percentage to total length (between either speaker and your ear). To give you a better picture, assume that AB is the lenght between the left speaker and your ear. AC is the length between the right speaker and your ear. The difference is AB-AC. You are trying to minimize both (AB-AC)/AB and (AB-AC)/AC.
A kickpanel install minimizes pathlength difference by increasing the total distance of speakers to your ears, therby lowering the difference in distance. (You increase AB without increasing AC--which is longer--so much so the difference between AB and AC gets smaller).
To reply to your friend's comment, try this experiment in your den or other suitable room at home: Get two smallish bookshelf speakers and place them in the approximate places where the kickpanel mounted speakers would go. Make them face each other as they would in your car. Play some music and sit right in the middle of the two speakers, a couple of feet or so back. Close your eyes and listen. Music sounds like it's coming off the floor, right? Now angle the speakers so they face you. Close your eyes and listen again. Not too shabby, eh? Tell your fried you don't have ears near your stomach or chest either but car speakers are placed in that general area too
(The experiment above, by the way, is meant to show that proper speaker placement in a kickpanel installation can work. It wasn't meant to prove the pathlength difference part of the question, although you could also prove it using the same equipment. You just need stools or something similar to place speaker on to approximate chest level mounting height and you have to sit closer to the left speaker.)
The drawback I've noticed in kickpanel mounting is the relatively low position of the soundstage (after all, everything is a compromise...) You would want the sound stage to be ideally centered *around* eye level. The workaround I've found to this would be to get additional tweeters, preferably the same ones you use in the kickpanel, and mount them far deep in the dash corners. You would need a separate amp, yes. The trick is to attenuate the dash tweeters enough so that they only work as a "fill" effectively raising your soundstage without drawing any attention to themselves.
In an Expedition/F150 setup, I haven't found a better arrangement than getting a good three way system, mounting the woofers in the stock door location (8-10 in.) mids and tweets in the kickpanels, extra tweets in the dash. Took a lot of trial and error, to-ing and fro-ing, but those are the results of more than a year of on and off experimentation. I guess the same would apply for most vehicles, though I haven't tried so I can't say for sure. Logically, it should be applicable.
Then again, you can get a McLaren F1 that has the driver right smack in the middle of the cabin, then you can mount everything on the dash and not have path length difference problems. But that car costs around a million bucks. One of my clients just bought one. (I'm an investment banker.)
How's that?
------------------
Thunder
rainmaker@attglobal.net
Black 97 Expedition EB 5.4L 4WD
Mods: Lightning Wheels, Pirelli Scorpion Zero 285/55VR18, K&N Gen II Kit, JET Chip
Brembo 14" disc brake kit coming right up!!!And hopefully a Lightning engine too!!!
Audio: McIntosh MX406, McIntosh MCD4000, Zapco SX-SL, Zapco EQ30, Genesis Monoblocks (3), Genesis Dual Mono, Dynaudio System 340, Dynaudio System 220, JL Audio Stealthbox
[This message has been edited by Thunder (edited 01-28-2000).]
Senior Member
Joined: Jul 1999
Posts: 1,929
Likes: 1
From: Oklahoma City
I put tweeter high in the door panel right under the window (above the power lock switch) and I am happy with the imaging.
The tewwer you are closer to is off axis reducing the volume.
This doesn't adress the time delay issue, but is a lot easier than building costom kicks or paying through the nose for Qforms.
(which the ppl on Sounddomain say the Qforms aren't that good anyway)
I would put the midbass in the stock location and experiment with tweeter placement.
Find out what sounds best to YOU before decidng on a permanant arrangement.
The tewwer you are closer to is off axis reducing the volume.
This doesn't adress the time delay issue, but is a lot easier than building costom kicks or paying through the nose for Qforms.
(which the ppl on Sounddomain say the Qforms aren't that good anyway)
I would put the midbass in the stock location and experiment with tweeter placement.
Find out what sounds best to YOU before decidng on a permanant arrangement.
Thread Starter
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Member
Joined: Jan 2000
Posts: 61
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From: Calgary, Alberta, Canada
Thanx "Thunder" and "54regcab" I appreciate the 'term paper' (I was glued to my monitor!). It is all very clear to me now! I think that I used to know about the time delay but somehow forgot! I helped a buddy install a tweeter or 2 in the center A/C vent to help with this as well (poor man's center channel). I think we used the + terminal of the left, and - terminal of the right speaker to do this(???).
As for the McLaren F1, I couldn't afford the brochure! I used to race open wheel cars (Formula 2000) so when I 1st saw that baby it was drool city! Ask you client if we can do a road test review for F150Online and I'll fly down to help you!!!
Back to my truck (and reality!). I have a great deal of equipment in the basement:
2 HiFonics Herculies 200 watt mono sub amps,
2 Soundstream SS10R subs
1 pair of Soundstream 6.5" seperates with 24db passive X-over
1 Soundstream D200II 2 ch. amp
1 HiFonics Pluto 60 watt 2 ch. amp
1 Audio contol EQX
1 Hifonics io Bass cuttoff (Dumps Bass below an adjustable level ie. 20hz.)
1 pair of AVI 8" woofers (mid-bass)
and perhaps more that I can't remember.
Here's the plan...
1 10" under the lifted rear seat (after I design/build a lift kit), powered by 1 Herc.
1 Pair of 8" in the stock rear locations, driven by D200II.
seperates in the front doors, powered by the Pluto (or after Thunders reply and some experimenting, perhaps Kick panels).
I realize this will give any back seat passengers a crappy sound expierience but... If they were more inportant they could ride up front!!!
Thanx Again
Bruce
As for the McLaren F1, I couldn't afford the brochure! I used to race open wheel cars (Formula 2000) so when I 1st saw that baby it was drool city! Ask you client if we can do a road test review for F150Online and I'll fly down to help you!!!
Back to my truck (and reality!). I have a great deal of equipment in the basement:
2 HiFonics Herculies 200 watt mono sub amps,
2 Soundstream SS10R subs
1 pair of Soundstream 6.5" seperates with 24db passive X-over
1 Soundstream D200II 2 ch. amp
1 HiFonics Pluto 60 watt 2 ch. amp
1 Audio contol EQX
1 Hifonics io Bass cuttoff (Dumps Bass below an adjustable level ie. 20hz.)
1 pair of AVI 8" woofers (mid-bass)
and perhaps more that I can't remember.
Here's the plan...
1 10" under the lifted rear seat (after I design/build a lift kit), powered by 1 Herc.
1 Pair of 8" in the stock rear locations, driven by D200II.
seperates in the front doors, powered by the Pluto (or after Thunders reply and some experimenting, perhaps Kick panels).
I realize this will give any back seat passengers a crappy sound expierience but... If they were more inportant they could ride up front!!!
Thanx Again
Bruce