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ctc911ctc
All,

Been silent, very cold - garage is a 100 year old Yankee version, no heat.....will not hold any. So, my 17yr old son and I decided to upgrade the speakers (the old ones were absent any cone material).

Found a set of KFC-4675C (kenwood) that fit the spec, integrated mid range and tweeter. Now for the low range. We decided that carving up the car and running a large alternator and battery was not for this car, we are trying to restore it to 80-90 points. So we are using a passive crossover, the original tuner with a power amp that was installed in the 80s, still works (both units are Blauplunkt). We have about 40 watts - more than enough for the size of the car.

When we rebuilt the car we installed sound deadening material in the engine bay, passenger compartment and will put it in the trunk. Amazing how quiet the car seems in the passenger compartment now.

My son had the idea to install the Subwoofer in the engine compartment, cut through the back seat - had to explain the concept of FireWall to him, we looked at a dozen other places and settled on what I think is a very elegant solution.


Our car is a '74 2.0, Silver. So it has a center console. We are installing it there!

Click to view attachment

First, where should the speaker go????

Click to view attachment

Wow - no particle board - furniture grade ply!

Click to view attachment

Peel back the Vinyl, careful!

Click to view attachment

Counter sync for flush hidden finish

Click to view attachment

Score the vinyl, perhaps we can STRETCH it!

Click to view attachment

Heat gun and PULL, gently

Click to view attachment

Look at that circle, no wood showing, barely a wrinkle!

Click to view attachment

Add a screen

Click to view attachment

Bolt that Micro SubWoofer in place

Click to view attachment

What the Passenger will see

Click to view attachment

Perfect Fit

Click to view attachment

Passive Crossover


Will post a note as to how this sounds in a few weeks (months?)
preach
Pretty good spot.
My Cayman's factory sub is a bump on the left of the p-side footwell.
MiniStevieG
QUOTE(ctc911ctc @ Jan 28 2019, 06:42 PM) *

All,

Been silent, very cold - garage is a 100 year old Yankee version, no heat.....will not hold any. So, my 17yr old son and I decided to upgrade the speakers (the old ones were absent any cone material).

Found a set of KFC-4675C (kenwood) that fit the spec, integrated mid range and tweeter. Now for the low range. We decided that carving up the car and running a large alternator and battery was not for this car, we are trying to restore it to 80-90 points. So we are using a passive crossover, the original tuner with a power amp that was installed in the 80s, still works (both units are Blauplunkt). We have about 40 watts - more than enough for the size of the car.

When we rebuilt the car we installed sound deadening material in the engine bay, passenger compartment and will put it in the trunk. Amazing how quiet the car seems in the passenger compartment now.

My son had the idea to install the Subwoofer in the engine compartment, cut through the back seat - had to explain the concept of FireWall to him, we looked at a dozen other places and settled on what I think is a very elegant solution.


Our car is a '74 2.0, Silver. So it has a center console. We are installing it there!

Click to view attachment

First, where should the speaker go????

Click to view attachment

Wow - no particle board - furniture grade ply!

Click to view attachment

Peel back the Vinyl, careful!

Click to view attachment

Counter sync for flush hidden finish

Click to view attachment

Score the vinyl, perhaps we can STRETCH it!

Click to view attachment

Heat gun and PULL, gently

Click to view attachment

Look at that circle, no wood showing, bearly a wrinkle!

Click to view attachment

Add a screen

Click to view attachment

Both that Micro SubWoofer in place

Click to view attachment

What the Passenger will see

Click to view attachment

Perfect Fit

Click to view attachment

Passive Crossover


Will post a note as to how this sounds in a few weeks (months?)


I love it. Nice work man! Very impressed with your attention to detail. You taking orders?
windforfun
Don't forget to reverse the phase relative to the "full" frequency range loudspeakers. Your crossover may permit this. It can make a huge difference in the sound quality.
ConeDodger
You could have just purchased this already made from 914rubber.com. @mikey914 if the are still making them.
ctc911ctc
QUOTE(MiniStevieG @ Jan 28 2019, 08:48 PM) *

I love it. Nice work man! Very impressed with your attention to detail. You taking orders?



I will ask my boss, the 17 year old in the picture! HA!
Mikey914
Nice work, but to get decent sound you need to box it in. I’ll post some pics of the one we do so you can see it.
Mark
ctc911ctc
QUOTE(Mikey914 @ Jan 29 2019, 03:00 AM) *

Nice work, but to get decent sound you need to box it in. I’ll post some pics of the one we do so you can see it.
Mark


Hey Mikey,

As to the BOX, the passenger compartment is box enough! At the frequency range we are at, we do not need projection just coupling.

Will post how it sounds, just trying to fill in the 100-1000.

I read that you made these? could not find them on your site.. Link please?

CTC911CTC
Chi-town
There's a guy on ebay who sells this set up too
amfab
QUOTE(ctc911ctc @ Jan 29 2019, 07:01 AM) *

QUOTE(Mikey914 @ Jan 29 2019, 03:00 AM) *

Nice work, but to get decent sound you need to box it in. I’ll post some pics of the one we do so you can see it.
Mark


Hey Mikey,

As to the BOX, the passenger compartment is box enough! At the frequency range we are at, we do not need projection just coupling.

Will post how it sounds, just trying to fill in the 100-1000.

I read that you made these? could not find them on your site.. Link please?

CTC911CTC

If it is not a sealed or ported box you will be putting negative and positive pressure into the box of the passenger compartment simultaneously and the pressure waves will cancel each other out below the frequency at which the open console acts as a small baffle.

-Andrew
Chris914n6
Speakers need to be in an enclosure to be effective.

Notice how the stock speakers suck for anything but voices, it's because the speaker is essentially in free air. Notice how fuller door speakers sound in modern cars... they have been engineered with the door as the 'box'.
Bose speakers are actually in tuned plastic 'boxes' that are mounted in the doors.
dr914@autoatlanta.com
best to put the sub woofer where the passenger foam block under the bulkhead carpet rests. Works perfectly, cannot tell any difference in the interior appearance:
Rand
QUOTE(dr914@autoatlanta.com @ Jan 29 2019, 10:09 AM) *

best to put the sub woofer where the passenger foam block under the bulkhead carpet rests. Works perfectly, cannot tell any difference in the interior appearance:

Doesn't matter if it's in the footwell or the center console. Both are equally stealth. What matters is the design of the enclosure as has been said here. A speaker enclosure should be air-tight behind. Either place requires fiberglass work to make the box work. If you don't have a tight box you are losing 10x the pleasure (sound) by design. Unplanned innuendo.
914forme
agree.gif Or ported, band passed, etc....

And then if you want to go deep, we can go into matching the speakers to the enclosure or the enclosure to the speaker and on and on and on....

I think it is a great attempt, now just seal the box and see what you get. Might be good, might be a learning experience, just do not treat it as a failure.
Mikey914
Not a failure, just brought up the sealing to help improve your product.
horizontally-opposed
QUOTE(dr914@autoatlanta.com @ Jan 29 2019, 10:09 AM) *

best to put the sub woofer where the passenger foam block under the bulkhead carpet rests. Works perfectly, cannot tell any difference in the interior appearance:


If someone makes a box for this—which lost no legroom, I'm interested. Much more appealing than the center console, as it could end up invisible (and I don't have a center console in my car, something I suspect is true for many 914s).

Even a mild bass "box/tube" that was well designed and didn't eat up any more legroom than the foam block would be a nice improvement.
ctc911ctc
QUOTE(amfab @ Jan 29 2019, 11:37 AM) *

QUOTE(ctc911ctc @ Jan 29 2019, 07:01 AM) *

QUOTE(Mikey914 @ Jan 29 2019, 03:00 AM) *

Nice work, but to get decent sound you need to box it in. I’ll post some pics of the one we do so you can see it.
Mark


Hey Mikey,

As to the BOX, the passenger compartment is box enough! At the frequency range we are at, we do not need projection just coupling.

Will post how it sounds, just trying to fill in the 100-1000.

I read that you made these? could not find them on your site.. Link please?

CTC911CTC

If it is not a sealed or ported box you will be putting negative and positive pressure into the box of the passenger compartment simultaneously and the pressure waves will cancel each other out below the frequency at which the open console acts as a small baffle.

-Andrew


Not too concerned, coupling will be ok, Lamda is large, blocking is present.

Thanks, will let you know how it works.
CTC911CTC
drem914
QUOTE(horizontally-opposed @ Jan 29 2019, 02:25 PM) *

QUOTE(dr914@autoatlanta.com @ Jan 29 2019, 10:09 AM) *

best to put the sub woofer where the passenger foam block under the bulkhead carpet rests. Works perfectly, cannot tell any difference in the interior appearance:


If someone makes a box for this—which lost no legroom, I'm interested. Much more appealing than the center console, as it could end up invisible (and I don't have a center console in my car, something I suspect is true for many 914s).

Even a mild bass "box/tube" that was well designed and didn't eat up any more legroom than the foam block would be a nice improvement.


The sub box you seek is available at 914Rubber.com and a vendor on ebay. Just look up Porsche 914 subwoofer. covered in black or grey perlon, fits an 8" sub.
Jonathan Livesay
I made this one, with a dedicated power amp for the sub and four other speakers it's probably over kill for a concert hall the size of a 914 cockpit. biggrin.gif Click to view attachment
horizontally-opposed
QUOTE(drem914 @ Jan 29 2019, 03:11 PM) *

The sub box you seek is available at 914Rubber.com and a vendor on ebay. Just look up Porsche 914 subwoofer. covered in black or grey perlon, fits an 8" sub.


^ Many thanks!
horizontally-opposed
QUOTE(Jonathan Livesay @ Jan 29 2019, 03:29 PM) *

I made this one, with a dedicated power amp for the sub and four other speakers it's probably over kill for a concert hall the size of a 914 cockpit. biggrin.gif Click to view attachment


What size in the factory speaker boxes?? Very interesting...
Jonathan Livesay
QUOTE(horizontally-opposed @ Jan 29 2019, 03:56 PM) *

QUOTE(Jonathan Livesay @ Jan 29 2019, 03:29 PM) *

I made this one, with a dedicated power amp for the sub and four other speakers it's probably over kill for a concert hall the size of a 914 cockpit. biggrin.gif Click to view attachment


What size in the factory speaker boxes?? Very interesting...

They are Kenwood 4X6 as I recall, the stock mount doesn't leave room for the magnets so I shimmed out the inboard side by about 1/2 inch. The stock grills were in a bunch of parts that I bought at one point and they were already cut up like that, as were the door panels.........I didn't do it! smile.gif
horizontally-opposed
QUOTE(drem914 @ Jan 29 2019, 03:11 PM) *

The sub box you seek is available at 914Rubber.com and a vendor on ebay. Just look up Porsche 914 subwoofer. covered in black or grey perlon, fits an 8" sub.


Was just all over 914rubber.com...have to say it was a bit tough to navigate, but could not find speaker enclosures—this after finding the link that promised them...

https://shop.914rubber.com/Body-Parts_c38.htm

Have a better link? Or...Mikey?

Thanks!

pete
SteveL
Sorry for the hijack but....
I need to replace the 20 year old deck in my 74.
Already have holes in door panels (previous owner, not me).
I know little about car stereos nowadays. I want decent sound. I would like a head unit that can connect bluetooth or at least have an aux in. Is there one that has enough good power output to not need a separate amp for decent sound? What would be good 6" speakers for the door holes?
Thanks
Mikey914
Just hearing up for another run. Finished off the plywood with bends and sewing up the covers now.

Moving to the new website but here's one we did. Even have the harness that fits directly to the prewirring in the later card to add the 3 gages.
Mikey914
More
Mikey914
This will allow you to add it later as an option.If you so choose.
Mark Henry
I have to figure out this as well for my 914. I have the sub box that fits in passenger footwell (morph?) but I don't like it as I'd have to hack the original carpet to make it fit.

So it's either in the console or behind the passenger seat, I didn't really want to run a console, so I'm going to look behind the seat first. I'll remove the 8" sub from the box and see where it fits, that way I can check without investing in a sub right away.
Mikey914
There is some room in the center section of the 3 piece back pads where the foam currently is. I'd say at the base would be good. I was planning to to do exactly that.

Behind the seats not as much.
Mark Henry
So hacking on the interior, I don't want to cut the carpet for the foot box so obviously this is no go for me. I didn't really want a console but for me it looks like the only solution.

I think I'll also look at having a go at a homebuilt console. I'm not going to hack up the console I have, but I can use it for a pattern. I already have the black vinyl and I just inherited my mom's Bernina sewing machine, so maybe it's a good time to learn how to use it.

What about a round one inch spacer between the speaker and console box? That could give a bit more interior volume and likely not interfere much in the passenger footwell.
horizontally-opposed
QUOTE(Mark Henry @ Jan 14 2020, 05:39 AM) *

So hacking on the interior, I don't want to cut the carpet for the foot box so obviously this is no go for me. I didn't really want a console but for me it looks like the only solution.

I think I'll also look at having a go at a homebuilt console. I'm not going to hack up the console I have, but I can use it for a pattern. I already have the black vinyl and I just inherited my mom's Bernina sewing machine, so maybe it's a good time to learn how to use it.

What about a round one inch spacer between the speaker and console box? That could give a bit more interior volume and likely not interfere much in the passenger footwell.


I had a Kenwood bass wedge in the passenger footwell years ago with a piece of plywood over it...all in lieu of the factory's "wasteful" foam wedge filler used to build out a nice place for the passenger's feet. It worked pretty well, and wasn't obvious visually but it really cut down on passenger legroom...so I removed it.

If I had a center console, or wanted one, the solution in this thread would be my go-to, but I'd dearly love a fiberglass box made to fit the 914 footwell like the factory foam while maximizing air space (upward? or to the right) and properly ported. I'd be interested in something like this if it meant running a smaller bass driver. Some of the home speakers these days make amazing bass from small packages. I wonder if there is even a way to "double port" it to the front trunk for more volume, but must confess I don't know how bass works in that regard.

Not sure making one as a one off makes sense, but it seems like a wonderful product for 914rubber if it's relatively easy to do. Could be furnished in raw fiberglass, and would be instantly reversible if the factory foam block is stored in the garage.
Mark Henry
I have the morph footwell 8" sub enclosure, it does fit the area OK, but you can't install it without cutting up my close to perfect OE carpet. Then you have to protect the woofer with something, the PO had an AL footboard with big ass spacers, you have to be a munchkin because it takes up so much legroom. It came out of the wife's 914, it's likely going back because her carpets are crap, but I'll figure out a better guard for the speaker.

I reason I don't care for the console is because anything but slippers I catch my right foot between the console and brake pedal. I think I'll DYI a console/box but space the speaker hole a bit more rearwards then the one in Mark's above pic. That way I hope I can clearance the right foot area a bit better.

Right now I'm fighting with two 4.0 996 rebuilds that won't let me catch a break, a 914 2056cc stock build that has to be done, need to fully kit out another 2.0 longblock and a 2007cc T1 build. These all have to be done before I can play with my own cars.
dry.gif
oakdalecurtis
"reason I don't care for the console is because anything but slippers I catch my right foot between the console and brake pedal."

Hey Mark, I have size 13 shoes and I too would drag my brake pedal with my right foot. I finally hacksawed the brake pedal off right at the end of the arm, (did it in the car without removing pedal box). Then I welded a short piece of steel 1/4 inch flat stock with 2 predrilled holes to the back of the pedal, offset to the right side of the pedal, as you look at it from the front. Then I welded a small steel gusset between the extension arm and the pedal to add support from pedal pressure being now on one side on the extension arm. Finally I drilled 2 matching holes in the brake pedal arm aligned with the extension holes and bolted it all together on the left side of the brake arm. I have a included a crude diagram below to show the simplicity of the process. It took me about 30 minutes to do, all "in car", and was not as hard as I made it sound. Now my brake pedal has about a half inch clear on the side of my big shoes, and makes a real pleasurable difference driving the car.

Click to view attachment
burton73
QUOTE(dr914@autoatlanta.com @ Jan 29 2019, 10:09 AM) *

best to put the sub woofer where the passenger foam block under the bulkhead carpet rests. Works perfectly, cannot tell any difference in the interior appearance:



Not so good with a 1970 or 71 car


Bob B
R Dub
ctc911ctc what sub did you go with? Also have you installed it yet? If so how does it sound?
horizontally-opposed
Maybe a stupid question, but: Could the doors be used more effectively when it comes to bass? I'm wondering if a 6.5 in the door with a small port tube venting back into the interior (by the back of the door, near the seat?) would work better than simply placing the speaker in the usual spot?

I am also wondering if one might figure out a way to mount said 6.5 behind the door panel and then make holes between the bricks in the door card's basketweave in a (perhaps compromised) version of the speaker holes seen in early 928s.

Just thinking out loud here; not sure what the ramifications would be in audio terms. If we have any audio experts, I'd love to hear from them.
ctc911ctc
How does it sound?

In the 70's I worked at Miller Audio on Wilshire in Beverly Hills. They made subwoofers called the M&K 1, then 2, then 3, etc. The drivers were suspended speakers and needed an unported enclosure. Took one home and paired it with two satellite speakers from Pyramid. $$$$$


I then studied EE and always read the acoustic proceedings of the IEEE. When I started making money I spent a great deal on audiophile-grade components chasing THD, sonic coupling and other audiophile absurdities seeking the perfect sound. Back at Miller audio, they started pressing Direct-to-Disk recordings to also chase the perfect sound. Such a holy grail.

My ears are now old - the sub-woofer in the car sounds great to me and my 18-year-old son who did the work loves the sound.

All that said for the following. In a small enclosure, a lot of what has been said on this thread is not necessary. We used a driver that did not require acoustic suspension (airtight enclosure) since it is very stiffly suspended, We used the middle counsel as the enclosure with the ports being the top and front opening. Bass waves at 10-300hz are very large, so getting great bass in such a small space and driver is difficult. Most audio engineers use acoustic coupling to the entire car just to get close to a small fraction of Lamda. However, we spent a great deal of time welding the car back together so I am against putting an audio jackhammer inside the car assaulting every component of the automobile.

Here is the driver we used:
https://www.amazon.com/gp/product/B00NHTXXN...=UTF8&psc=1

Also, we used a passive crossover and a 400-watt amp (peak) - make certain the amp only goes on when you are using it - ask me why I say this! headbang.gif

What I like most is not having to cut the car apart (holes in the doors) - we put in new Jenson speakers within the original enclosure and also used the original radio to turn on the power amp and to play the radio, though my son plays his phone most of the time. 70's rock is his favorite - Seriously!

Send pictures of your system and your decisions.....

No matter what you do, you probably won't listen very often, the engine sounds too cool! A good friend has a Ferrari with a very high-end audio system installed. When I asked him how it sounds he replied that he never turned it on.......then we went through a tunnel.......THAT'S MUSIC..........ahhhhh biggrin.gif biggrin.gif







QUOTE(R Dub @ Jan 18 2020, 03:03 PM) *

ctc911ctc what sub did you go with? Also have you installed it yet? If so how does it sound?

gereed75
I know this is a DIY spirited kind of thread, but this seems like a pretty straightforward solution

https://www.amazon.com/Rockville-RockGhost-...0NsaWNrPXRydWU=

Anybody ever try one?
914forme
the trunk is semi sealed from the cabin.

You using this to keep mice out of the car.
FlacaProductions
I'm away from my 914 for extended periods so I do a lot of research/reading in the meantime - wondering if something like this would fit under our seats?

https://www.amazon.com/gp/product/B019Z3RFG...sk_ql_qh_dp_hza

Dimensions: 12.4 x 11 x 2.7
tomeric914
These are all great suggestions to the OP, but he did this with his son as a project. That system will sound amazing for years to come. You can't buy that kind of quality anywhere. wub.gif
Chris914n6
QUOTE(FlacaProductions @ Jan 19 2020, 09:26 AM) *

I'm away from my 914 for extended periods so I do a lot of research/reading in the meantime - wondering if something like this would fit under our seats?

https://www.amazon.com/gp/product/B019Z3RFG...sk_ql_qh_dp_hza

Dimensions: 12.4 x 11 x 2.7

L & W yes but the seat is only 1" or so above the floorpan. I did put an amp under the pass seat years ago by adding spacers to the rear mount and a bit of indenting the floor. smash.gif

FlacaProductions
Dang- that's what I thought
steuspeed
QUOTE(horizontally-opposed @ Jan 18 2020, 06:25 PM) *

Maybe a stupid question, but: Could the doors be used more effectively when it comes to bass? I'm wondering if a 6.5 in the door with a small port tube venting back into the interior (by the back of the door, near the seat?) would work better than simply placing the speaker in the usual spot?

I am also wondering if one might figure out a way to mount said 6.5 behind the door panel and then make holes between the bricks in the door card's basketweave in a (perhaps compromised) version of the speaker holes seen in early 928s.

Just thinking out loud here; not sure what the ramifications would be in audio terms. If we have any audio experts, I'd love to hear from them.


You could do a 3 way separate system. One Idea I had for my car with already cut door panels. Buy a 3 way kit. Use the tweet and mid under the stock grill and the woofer in the door.
Chris914n6
QUOTE(FlacaProductions @ Jan 19 2020, 02:15 PM) *

Dang- that's what I thought

Peaked my interest enough to get crafty. The Rockwell ss8p is a better fit.
Between the seat rail.
Custom center console.
Under the dash with and without the glove box.

IPB Image

IPB Image

IPB Image

IPB Image

IPB Image
horizontally-opposed
It's seriously tricky.

Everything I've tried in the footwell either crimps toe space or foot space. I'd love a really well designed, sealed fiberglass bass box built to replace the factory foam...but not sure it would work? Or would it? Suspect the bass speaker would have to be pretty small, and maybe the enclosure would have to be modeled on some of the bass-creating "boxes" from major brands. I had one of those that was actually shaped as a wedge that went into that space pretty well, but it was old, tired, and probably moisture-damaged.

Which has moved me back to seeing what's possible to do with the doors...whether they would benefit from a rigidly mounted 6.5 and maybe even with a port someplace else on the door. Not sure the door is sealed "enough" to make that port worth it.

I sometimes look at this stuff, at 12x13x2.7 inches (or thereabouts), but it's usually powered... https://www.amazon.com/dp/B019Z3R582/ref=ps...1_t2_B01FV0IAQO
messix
check this thread out.

my sub box that is now sold by 914rubbers is in post 15 and 16/

it's a good tight bass with good volume.

http://www.914world.com/bbs2/index.php?sho...mp;hl=subwoofer
FlacaProductions
@messix - I think that's the way to go but I can't find it on 914Rubber's site. @Mikey914 ?
dr914@autoatlanta.com
the best place is to put a sub woofer is where the foam floor board block exists on the passenger side. Totally hidden, takes up no space, sounds GREAT and does not chop up the car. Here is a picture if anyone wants to make one: http://www.autoatlanta.com/Porsche-914-Spe...N-BAA31934.html

It is very easy to make, basically the pattern of the block with a leg to support it. We have made hundreds over the years and the sound is great, and TOTALLY hidden

Rand
I can vouch for Troy's setup. It kicks.
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