69 Dash Support blocks dash speaker installation
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 2,608
Likes: 3
From: TEXAS - you mean there are other states?
69 Dash Support blocks dash speaker installation
I am at the stage of re-installing my dash on my 69, and see that the horizontal dash support prevents installation of dash speakers.
Back in the day, I got a newer model dash that had speakers (what 1970 and up???) I guess I forgot I removed the support to make the speaker install work.
Today, I do not know if I want to give up that horizontal support... in fact I don't know if the dash speakers are that advantageous - probably kick panels are a much better option.
Regardless - I need to make a decision. What have ya'll done when you encountered this?
Back in the day, I got a newer model dash that had speakers (what 1970 and up???) I guess I forgot I removed the support to make the speaker install work.
Today, I do not know if I want to give up that horizontal support... in fact I don't know if the dash speakers are that advantageous - probably kick panels are a much better option.
Regardless - I need to make a decision. What have ya'll done when you encountered this?
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Yes the kick panel location is better. About all the dash location is good for is tweeters. I disconnected the dash speakers in the 70s. Removing the dash speakers can give a more open airy sound & raise the soundstage.
Some 5.25 can be fitted to kick panel location. The 4x6 dash speakers fit. A mounting plate must be used to separate the front from back sound waves to prevent cancellation for better bass.
Some 5.25 can be fitted to kick panel location. The 4x6 dash speakers fit. A mounting plate must be used to separate the front from back sound waves to prevent cancellation for better bass.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
If the dash speaker work and are not raspy, why not just leave them there and wire them up with some additional kickpanel speakers. The dash speakers are only for upper mid-range and high frequencies, anyway. Buy a couple of good quality 2-way speakers (5"x7" or 5-1/4" round) that have four ohm impedence. Then just wire the speakers on each side in series [not parallel]. That will result in 14 ohm speaker match to a 10 ohm amp output. It will drop the maximum volume level just a bit, but it won't do any damage to the radio/amp...and the sound will be drastically improved with the bass/mid-range music coming out of the kickpanels and the highs coming out of the dash speakers and reflected to you directly by the windshield glass. 
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 2,608
Likes: 3
From: TEXAS - you mean there are other states?
Ganey - where is this mounting plate that you mentioned?
Maybe I should have adjusted one of my Q's to read "Is the horizontal support advantageious and what did they do in 1970+ models?" I would not mind keeping the 4" x 6" speakers, but the OEM horzontal support completely blocks the speaker from being installed. The support goes right through the 4" x 6" area designated for the speakers (1" below and directly through the center of the area.)
Hey - maybe with today's technology maybe a small tweeter could work in an 'offfset manner within the 4" x 6" area in the dash. I had planned on tweets in the door panel to cover my old manual window crank holes.. but I am open - maybe there is an insert to cover the manual crank holes.
Charley - I heard of the 4 ohm advantage - but the other comments you made, I will have to absord.... remember - voltage and I do not get along.........
Maybe I should have adjusted one of my Q's to read "Is the horizontal support advantageious and what did they do in 1970+ models?" I would not mind keeping the 4" x 6" speakers, but the OEM horzontal support completely blocks the speaker from being installed. The support goes right through the 4" x 6" area designated for the speakers (1" below and directly through the center of the area.)
Hey - maybe with today's technology maybe a small tweeter could work in an 'offfset manner within the 4" x 6" area in the dash. I had planned on tweets in the door panel to cover my old manual window crank holes.. but I am open - maybe there is an insert to cover the manual crank holes.
Charley - I heard of the 4 ohm advantage - but the other comments you made, I will have to absord.... remember - voltage and I do not get along.........
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 2,608
Likes: 3
From: TEXAS - you mean there are other states?
If you looked at the dash from a top view... and assume it is 4.5' wide x 1" tall.... the center brace I speak of runs underneath the dash and starts about the middle of each side (6"+-) and runs 4.5' directly across to the other side. Also - if you were to draw speakers where thye might be - it would be directly in line with the support.
I don't know if that is understandable - but.... I did review the AIM and its all good - along with bolt hoels to match ! for a change..
I don't know if that is understandable - but.... I did review the AIM and its all good - along with bolt hoels to match ! for a change..
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
A mounting plate needs to be made to separate the front from back sound waves to prevent cancellation for better bass.
Easy to make. vettfixr Al's topic shows the situation:
http://forums.corvetteforum.com/show....php?t=1049772
As for ohms, what radio are you using?
Easy to make. vettfixr Al's topic shows the situation:
http://forums.corvetteforum.com/show....php?t=1049772
As for ohms, what radio are you using?
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 2,608
Likes: 3
From: TEXAS - you mean there are other states?
I read his article and understand a bit better. Now just for overview, he used brackets to mount the speakers in a solid fashion. Then - to prevent the sound from travelling backwards into the birdcage, he used those weatherproof pods as the baffle.... I checked Crutchfield and they have some.
I was looking for how he made his kick panels mount smoothly with a 3/8" thick laminate to contend with....
Well - good info.
So - back to the dash support system - are 1970+ models without any horizontal dash support and if so - what is the alternative if any?
I was looking for how he made his kick panels mount smoothly with a 3/8" thick laminate to contend with....
Well - good info.
So - back to the dash support system - are 1970+ models without any horizontal dash support and if so - what is the alternative if any?
Last edited by kaiserbud; Feb 23, 2010 at 10:19 PM.
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Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
The plates I refer to are metal in mine & 3/8" laminate in Al's. This separates the front waves from back. MDF or plywood are also commonly used.
The pod in Al's is another issue.
I added some polyfill (or foam could be used) behind the speaker in the box which can help by absorbing the back waves & making the box appear larger to the speaker.
There is a dash support in later models that is to the right of the center of dash like a shelf support front to back.
The pod in Al's is another issue.
I added some polyfill (or foam could be used) behind the speaker in the box which can help by absorbing the back waves & making the box appear larger to the speaker.
There is a dash support in later models that is to the right of the center of dash like a shelf support front to back.
