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Technical => Audio & Other Aftermarket Electronics => Topic started by: thunderjet302 on July 27, 2015, 02:45:21 PM

Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on July 27, 2015, 02:45:21 PM
I got some new speakers for the Thunderbird to replace the stock 27 year old factory "Premium Sound" speakers (birthday gift FTW). I ended up with the following speakers:

Front door: Polk Audio DB651 6.5" speakers
Dash: Polk Audio DB351 3.5" speakers
Rear deck: Polk Audio DB691 6X9" speakers

The dash and door speakers were direct replacements for the factory size speakers so no issues there. Now the factory rear deck speakers are 5X8" speakers. I wanted 6X9" speakers in the rear deck because, well, bigger is better :hick:. I also wanted the 6X9" speakers in the rear deck to fit under the factory speaker grills and mount in the factory location. Usually this is a problem because the factory "rubber band" mounts won't fit over aftermarket speakers. Well I found a way around this issue. Lincoln Mark VIIs have the same rear speaker mounting system our cars do except they have factory 6X9" speakers in the rear deck. I swiped some speaker mounts from a 91 Mark VII at the wrecking yard. They didn't fit around the bottom of my Polk speakers very well so I ended up having to trim about 1/8" off the inside of the rubber mount. After I did that they fit around the Polk speakers perfectly. I was able to mount the speakers in the stock location using stock style mounts and even have them fit under the stock speaker grills. Even with the stock "Premium Sound" amp these Polk speakers make a world of difference. They are much crisper than the factory paper junk. The Polk 6X9s also added some thump the factory 5X8s lacked. Adding a small sub woofer and/or replacing the factory amp would probably improve the sound quality even more. I need a 3G swap first before I do any of those audio upgrades though.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: daminc on July 27, 2015, 03:12:11 PM
i had 6x9s back in 92 with the stock grills.. I cant remember how I got them to stay....I'll have to look because I think they are still in there
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: CoogarXR on July 27, 2015, 03:51:33 PM
When I had 6x9's in mine, I just lifted the carpet, drilled holes and put long screws in. Mount the speakers underneath, lay the carpet back down, and ta-daa.

I didn't know about the lincoln 6x9 rubber bands though. That sounds much easier.

FYI- my '80 bird had factory 6x9s too, but they were held in place with studs and nuts instead of the ol' rubber bands.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on July 27, 2015, 04:10:24 PM
I'm lazy and didn't really feel like pulling the back seat and sail panels to get the rear deck out to mount the speakers. Hence why I went with the Mark VII rubber band mounts. Worked like a charm once I make the hole larger to accommodate the bigger Polk speaker magnet.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Haystack on July 27, 2015, 05:36:23 PM
I thought 6x9's shared bolt patterns with 5x7's? I never had to mod anything.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on July 27, 2015, 05:53:59 PM
Quote from: Haystack;450131
I thought 6x9's shared bolt patterns with 5x7's? I never had to mod anything.

If you want to use the stock "rubber band" hangers you have to modify them.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: EricCoolCats on July 27, 2015, 10:29:34 PM
Good job, Lou. That's the correct way of making it work.

I did sort of the same thing on my '84. Except I went the extra-nerdy route. :hick:

So the earlier cars had the rear speakers attached to the rubber donut hangers, then a cardboard-style box lined with insulation goes over the speaker in the trunk, and that's held on with a glorified coat hanger. It's all just inane but this was also early 1980's technology so I'm a bit forgiving. The Premium Sound option, while popular later on, was sort of a pariah in 1983-84, and was more common with the LS/turbo cars. That means the base radio setup was just 4 speakers. Four measly, paper thin-coned speakers.

I wanted to upgrade the speakers in the '84 while still retaining the stock look and functionality. I've learned quite a bit in almost 30 years of working on these cars...so I actually applied a few lessons to this task.

FRONT SPEAKERS
- Remove dash top, remove speaker retaining bolts, pull speakers out of their respective dash holes...oops, that's right. Forgot that Ford was under budgetary restraints and couldn't give us one. More. Measly. Inch of wiring. So I have to reach under the dash to get to some things. But eventually I'm able to pop out the clips on the wiring harnesses, and out come the speakers. Nasty faded brown/tan fabric and all.

- De-solder the speaker wiring connections on stock speakers' wafer boards. Then drill out the pop rivet that holds the board to the speakers.

- On the new speakers, solder small wire leads onto each terminal (+ and -), then solder the wires to the wafer board. Find appropriate area and drill small 1/8" hole in speaker's metal backing, then attach with a new pop rivet.

- Clip stock harnesses onto the speakers, drop them in the holes, and bolt them back down.

- Place two 6"-square pieces of acoustically transparent fabric over the speakers.

- Replace dash top.


RESULT: Looking down through the holes in the dash top, it's impossible to tell what I've done. Which is exactly the point.
 
 

REAR SPEAKERS
- I'll be honest, it's pretty much the same as the front speakers. Except for, of course, the same issue as Lou had: the rubber donut was way too small for the new speakers.

- Then I remembered: somewhere in my stash was a pair of original Premium Sound rear deck speakers. Hmmm...

- The Premium Sound magnets were much bigger, and those rubber donuts slipped over the new speakers perfectly. Problem solved.

- Except that I'm better than this. I can go the extra step. ICANDOEET.

- I take all the time needed to heat up and remove the factory Premium Sound labels affixed on the bottom of the magnets.

- Glue the labels onto the new speaker magnets.

- Replace the cardboard box/coat hanger. Aaaaannnnddddd I'm done.

 
RESULT: Why would I go through the trouble to make an aftermarket speaker look like a Premium Sound speaker when, in fact, it will always be covered by a cardboard/insulation/wire sandwich?

Why, indeed. ;)

If I were to remove a rear speaker and hand it to anyone with a half-ounce of experience with these cars, they'd never know that it wasn't a stock Premium Sound speaker. Never. I'm the only one that knows. Er, knew. Oops.

Actually it's very easy to understand why I went through all this trouble: absolutely no cut wires. No modification to the stock connectors needed. No splices. No piggybacking of wires. Soldering makes sure it's a factory-style connection that is stable and secure. And zero issues to worry about. There were extra steps, sure, but this is something that virtually no one else would do. So I just did it.

Then I installed the 8-track radio. And then I built a custom Bluetooth 8-track module so I can stream music from my phone to the radio. But those are stories for another day, kids.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on July 27, 2015, 10:59:04 PM
I need to get a picture of what I did. It really does look stockish.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: TheFoeYouKnow on July 27, 2015, 11:32:32 PM
I've got OE Sony audio speakers from late model Fords.  3.5" in the dash, originally from the frond and rear center channel of an 11 Taurus, 6x8's from a 10 Flex (large old school maget) under the rear deck, fitted in the stock fashion, and 6x8's from the front doors of 12 Fusion (neodymium magnets) that I trimmed my doors to accept.  All those really nice dark grey poly cone jobs.  Still need a small sub and amp to fatten things up a bit.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on July 28, 2015, 11:12:13 AM
Quote from: TheFoeYouKnow;450147
I've got OE Sony audio speakers from late model Fords.  3.5" in the dash, originally from the frond and rear center channel of an 11 Taurus, 6x8's from a 10 Flex (large old school maget) under the rear deck, fitted in the stock fashion, and 6x8's from the front doors of 12 Fusion (neodymium magnets) that I trimmed my doors to accept.  All those really nice dark grey poly cone jobs.  Still need a small sub and amp to fatten things up a bit.

Sounds like a nice setup. I need to do a 3G conversion before I go adding anything else stereo related. I'm thinking of replacing the factory amp with a 100-150W unit and a 100w ish sub should improve the sound. The sound quality improved greatly with just the new speakers vs the paper cone 27 year old "Premium Sound" speakers.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: mcb82gt on July 29, 2015, 07:38:01 PM
I ve also wanted to swap in a aftermarket amp, in place of the premium sound amp.  Just so many other things to do.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Haystack on July 30, 2015, 12:29:21 AM
Quote from: thunderjet302;450156
Sounds like a nice setup. I need to do a 3G conversion before I go adding anything else stereo related. I'm thinking of replacing the factory amp with a 100-150W unit and a 100w ish sub should improve the sound. The sound quality improved greatly with just the new speakers vs the paper cone 27 year old "Premium Sound" speakers.


As much as i like my 3g alt, i see very little benefit from it as a whole. Lets take your 100 watt stereo and amp. 200 watts, or, 16 amps. Most speakers/amplifiers are rated at PEAK power output, not actual output. When i used to have my electric guitar, i could blow your ear drums with a actual 50 watt amplifier. My "200 watt" stereo? Meh, i can hear it at freeway speeds.

Now 200 watts peak probably means less then half that at full output, and probably half of that when your actually listening to the radio at a reasonable volume. That 16 amps was 200 watts at 12v's. At 14 v's it would be more like 12. So 1/4 12 is 4 amps. Approximately the same as two 1157 bulbs.

Even with quality audio components, 10 amps should be almost unbearable. It would be fun to hook my car stereo up to an amp meter.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on July 30, 2015, 11:50:09 AM
I've never really had a charging issue with the 2G but I'd like to do a 3G swap for piece of mind. Sitting at a stop light with the car in drive (650rpm idle speed) the voltage gauge gets to the low side of normal (3 bars on the digital gauge) with the A/C, headlamps, and stereo on.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Masejoer on August 21, 2015, 07:29:56 PM
Quote from: Haystack;450131
I thought 6x9's shared bolt patterns with 5x7's? I never had to mod anything.


Most "6x8" speakers are the same size as older "5x7. True 6x9's are quite a bit larger than the stock speakers - the mounting  is larger. Any mounting  on 5x7s would be in the cone on 6x9s.

6x9's were a nice upgrade for bass in the stock system, but they don't have any authority down low. They may get down to 30-40Hz at whisper volume levels, but driving down the highway at higher volume levels, they are excursion-limited (let's say, 2-3mm xmax) and have no output for lower notes from instruments (notably drums).

Congrats on the upgrade - I know it's a huge improvement!

I'm sure you'll want some nice subs soon enough! After moving to dual infinite-baffle subs, I can't go back to anything less - midbass or subsonic. You get incredible efficiency and smooth frequency response that can easily dip down into true "sub"woofer subsonic frequencies (<16Hz). Anything sealed will take thousands of watts and huge cones to get down to subsonic frequencies, and anything ported can't get down past the port's tune frequency without blowing the driver out. IB takes up almost no room, takes less power, and sounds awesome. After building a couple sealed 18" subs for my office, feeding them from a 1.8kW rms/channel amplifier, I wish I could fit a couple 18's infinite-baffle in the Thunderbird. DSP'd to blend in perfectly, there's so much that people don't realize their missing in some music (or movies)!
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on August 24, 2015, 08:51:10 PM
The new speakers are a huge improvement over stock. I am planning on adding a subwoofer at some point. First I need to do the 3G conversion so I've got enough amps to handle the woofer.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Masejoer on August 25, 2015, 02:21:10 PM
Quote from: thunderjet302;450816
The new speakers are a huge improvement over stock. I am planning on adding a subwoofer at some point. First I need to do the 3G conversion so I've got enough amps to handle the woofer.

Not necessarily - with my sealed 18" subs at home, playing a sine wave in a 800cuft room, I hit 105dB at 8-Watts per channel at 2-meters (2 channels) according to a Dayton UMM-6 microphone and REW. Infinite baffle would get even louder at 8W. I find 105dB about the upper limit of "comfortable", but loud listening, and it is technically well into ear-damage territory. I normally listen in the 80-90dB range.

At 8W (16W total for two coupled drivers), 15Hz is down to 98dB and 10Hz is down around 95dB. 6Hz drops to 83dB, and 3Hz dips down to just above my current noise floor (loud amp fans that I need to replace) at 67dB. My room's noise floor hovers at 58dB right now with the sub amp running, 32dB with it off. There is a lot of room/cabin gain to be found down low.

Most music, you will need well under 100W (under 10A from the alternator) for anything but peaks. Peaks will pull mostly from the battery, not the alternator. Don't be surprised if power draws are in the 10-30W range at higher volume levels. At 12V, that's 1-3 Amps. 100W will generally sound twice as loud as 10W. 1000W will sound about 4x as loud as 10W. Unless playing <20Hz (generally for movies), one doesn't need more than 100W for subs outside of competition. Rotary woofers work much better for <20Hz reproduction for movies, and take a fraction of the power (but cost a lot more up-front at the moment)

Car cabins are even smaller than a 10x10 room. With a proper install (prevent peaks and nulls, which make sound systems turn into one-note bass wonders - the "boomy" that some like, and most hate) and you don't need much power. Cancellation is your enemy.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on August 25, 2015, 04:23:12 PM
So basically a 3G alternator upgrade isn't a necessity to run a subwoofer? I'm actually surprised by that.

Any suggestion on a decent powered subwoofer that works well in our cars? The head unit I'm running has RCA outputs for a subwoofer. I'd really like to mount a subwoofer behind the factory trunk insulation so it's not visible when the trunk is opened.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Masejoer on August 25, 2015, 06:53:53 PM
Quote from: thunderjet302;450830
So basically a 3G alternator upgrade isn't a necessity to run a subwoofer? I'm actually surprised by that.

Any suggestion on a decent powered subwoofer that works well in our cars? The head unit I'm running has RCA outputs for a subwoofer. I'd really like to mount a subwoofer behind the factory trunk insulation so it's not visible when the trunk is opened.

If you want to keep the cargo room, your options are small (10") sealed subs under the rear deck, or infinite baffle. Ported needs a large box. For a cabinet taking up a small amount of room, a 10" will perform similarly to a 12" - bass needs a large cabinet size and without going larger, a 12" won't help you anymore than a 10". For a "powered" sub that comes as a package with built-in plate amplifier, you'll be very limited in choices. Products like the Infinity Basslink fill the requirement, but they're not remarkably powerful in terms of extension and output. Small sealed cabinets need a lot more power to get to lower frequencies, but you may not need that range - natural music won't play much below 50Hz, ever, with only synthetic sounds dipping down further, pipe organs, or explosions from movie soundtracks.

Back before I had any tools, I installed my subs infinite-baffle by cutting some MDF, mounting subs to them, mounting it all to the cross-braces behind the rear seat, and filling the gaps. It took a jigsaw, drill, and some bolts/washers/nuts. Two 10" subs infinite-baffle had good output down to 20Hz. Amplifier was stuck in the rear seat armrest area, behind the plastic panels. The setup took up next to no room and was very efficient. Sounded great. I still have these subs in the car, but would like to try fitting a couple 15" subs back there instead just for the hell of it. With infinite-baffle, the cabin acts like an oversized subwoofer box, instead of a puny little box tossed into the trunk - nice, smooth response, down into the subsonic ranges (high pass crossover/subsonic filter needed to protect the drivers - most amps come with them).

Just a couple cheap Infinity 1260w or 1262w subwoofer drivers mounted in a sealed, ported, or infinite-baffle install will create plenty of bass. Throw on a cheap, small 300-350W rms amp to power them and you have enough power for every listening, or enough power to make highschoolers think you're pushing 1000W+ into big ported 15's. The 1260 is a well-reviewed sub driver that people go to for value, even when running them in a larger home theater environment. Two of these in a trunk, running 300W shared between the pair (not 300W each, but 300W shared or 150W each), will have output numbers like a single subwoofer running 600W - acoustic coupling makes for more output than what you'd expect for the energy you put in.

A couple plate-amp'd subs like the basslinks would also benefit from running a pair, and acoustic coupling giving you 4x more output for 2 instead of only twice the output. As long as the subs are physically close to one another and not directly cancelling each other out , frequencies with longer sound waves will be acoustically coupled.

http://www.masejoer.com/Images/Thunderbird/ibsubs1.jpg (http://"http://www.masejoer.com/Images/Thunderbird/ibsubs1.jpg")
http://www.masejoer.com/Images/Thunderbird/ibsubs2.jpg (http://"http://www.masejoer.com/Images/Thunderbird/ibsubs2.jpg")
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Masejoer on August 25, 2015, 07:39:46 PM
Quote from: thunderjet302;450830
So basically a 3G alternator upgrade isn't a necessity to run a subwoofer? I'm actually surprised by that.

Any suggestion on a decent powered subwoofer that works well in our cars? The head unit I'm running has RCA outputs for a subwoofer. I'd really like to mount a subwoofer behind the factory trunk insulation so it's not visible when the trunk is opened.

If you want to keep the cargo room, your options are small (10" sealed subs) under the rear deck, or infinite baffle. For something taking up a small amount of room, a 10" will perform similarly to a 12" - bass needs a large cabinet size and without going larger, a 12" won't help you anymore than a 10". For a "powered" sub that comes as a package with built-in plate amplifier, you'll be very limited in choices. Products like the Infinity Basslink fill the requirement, but they're not remarkably powerful in terms of extension and output.

Back before I had any tools, I installed my subs infinite-baffle by cutting some MDF, mounting subs to them, mounting to the cross-braces behind the rear seat, and filling the gaps. It took a jigsaw, drill, and some bolts. Two 10" subs infinite-baffle had decent volume down to 20Hz. Amplifier was stuck in the rear seat armrest area, behind the plastic panels. Took up next to no room and was very efficient. Sounded great. I still have these subs in the car, but would like to try fitting a couple 15" subs back there instead just for the hell of it. With infinite-baffle, the cabin acts like an oversized subwoofer box, instead of a puny little box tossed into the trunk - nice, smooth response, down into the subsonic ranges (high pass crossover/subsonic filter needed to protect the drivers - most amps come with them).

Just a couple cheap Infinity 1260w or 1262w subwoofer drivers mounted in a sealed, ported, or infinite-baffle install will create plenty of bass. Throw on a cheap, small 300-350W rms amp to power them and you have enough power for every listening, or enough power to make highschoolers think you're pushing 1000W+ into big ported 15's. The 1260 is a well-reviewed sub driver that people go to for value, even when running them in a larger home theater environment. Two of these in a trunk, running 300W shared between the pair (not 300W each, but 300W shared or 150W each), will have output numbers like a single subwoofer running 600W - acoustic coupling makes for more output than what you'd expect for the energy you put in.

A couple plate-amp'd subs like the basslinks would also benefit from running a pair, and acoustic coupling giving you 4x more output for 2 instead of only twice the output. As long as the subs are physically close to one another and not directly cancelling each other out , frequencies with longer sound waves will be acoustically coupled.

Infinite Baffle Subs Front (http://"http://www.masejoer.com/Images/Thunderbird/ibsubs1.jpg")
Infinite Baffle Subs Rear (http://"http://www.masejoer.com/Images/Thunderbird/ibsubs2.jpg")
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: GDawg148 on August 25, 2015, 11:30:38 PM
Just found a parts Mark VII in my area.  I'll be doing this soon (my back speakers have been blown for a while now)
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on August 26, 2015, 03:26:25 PM
I've been thinking of adding this particular woofer: http://www.amazon.com/Infinity-Basslink-200-Watt-10-Inch-Subwoofer/dp/B000063TJY
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Masejoer on August 27, 2015, 01:41:47 PM
Quote from: thunderjet302;450847
I've been thinking of adding this particular woofer: http://www.amazon.com/Infinity-Basslink-200-Watt-10-Inch-Subwoofer/dp/B000063TJY

They'll improve the midbass, but thrown into the trunk, it may sound boomy. Better than no sub, and if you EQ it right, the sub should blend in fine. If you can put a 24db/octave 63Hz high pass crossover on the 6x9's from a headunit, you should be able to prevent them from bottoming out. If 12db highpass, I'd set the 6x9's at 120Hz. I have no idea what protection the speakers may have built-in - they could have a capacitor already.

Stock stereo, you can build your own passive crossover. http://www.the12volt.com/caraudio/crosscalc.asp . If you want the simplest filter with one capacitor per speaker, you'd probably want a 1st-order (3db/octave) crossover. With your speakers, 200uF would be down 3dB at 200Hz, 6dB at 100Hz, and 12dB at 50Hz.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: thunderjet302 on August 28, 2015, 11:58:35 AM
I may give it a whirl and see what happens. Right now the system is the stock EQ and amp with a JVC headunit (wired in with RCA preouts so it works like the stock radio) wired in place of the stock head unit and the Polk speakers.
Title: So you want 6x9 speakers in the rear deck? Yeah it'll work fine.
Post by: Masejoer on August 28, 2015, 02:18:32 PM
Quote from: thunderjet302;450903
I may give it a whirl and see what happens. Right now the system is the stock EQ and amp with a JVC headunit (wired in with RCA preouts so it works like the stock radio) wired in place of the stock head unit and the Polk speakers.


Ah, yeah give it a try.  You may be EQ-limited in your setup. Two of those subs would give you far deeper extension, but you would probably need to pull back the 50-125hz range by almost 10dB, if you want to get rid of boominess. With one sub, you should only need to pull 3dB from the 63-125hz range. If you like strong midbass, then just wire it in and go!

EQing can help bass a lot, even with poor subwoofer placement:

(http://www.masejoer.com/Images/REW.png)