Here's a simple solution to center speakers

[par4tom]

My 3 year project has finally gotten to the point that I get to do my favorite part of the install...the audio / visual system.

Here's the current status of my truck and today I'm working on the center channel Accent Fill.

For starters, I'm an "old" audiophile with many years of competitive experiecne in both Iasca and Usac events. These were popular around 15 years ago.

And my project now is a 1961 Chevy truck, standard cab. From the picture, you can see the stock opening for accent fill...

[par4tom]

Here's a photo of the underside of the dash...as you can see, there is not much to work with at first. But we'll quickly change that...

[par4tom]

As you can see from the post above, there is nothing to bolt the center channel assembly on to. So for starters, here is what I did...

I took a measurement of the stock speaker grill opening and cut a piece of 1/2 MDF slightly larger...in this case the piece I cut was 4" x 8"

[par4tom]

I then marked out about a 1/2 inch frame around the outside, drilled some pilot holes for my jig saw blade and then cut the opening. On the second picture, you can see the piece relative to the opening in the dash...

[par4tom]

For the next step...I took a piece of 1/4 pvc black plastic, a piece of 3/8 inch mdf and measure my cutouts for my speakers. In this case, I am using a pair of CDT Audio 2" accent fill speakers.

For this install, they require a 2 1/2" opening. But you can change the opening for whatever speaker you are using.



I marked the center of the opening in my frame for the speakers here...

And then drilled the 2 1/2 inch holes for the speaker mounts. I also drilled four holes along the perimiter of my mounting frame. They hold small 2 " bolts which will hold the entire assembly.

The picture just below that shows the PVC plastic faceplate with the CDT's mounted.

I then epoxied 2" PVC end caps to the back of my 1/4" mdf. These will be the chambers for the backs of these drivers and is what Ken at CDT Audio recommended for my accent fill...after that, I mock every thing up to make sure my assembly will fit together...

[par4tom]

To mount the frame under the dash, I used 5 minute epoxy GEL (it doesn't run like regular epoxy) and lathered it onto the top of the frame like icing a cake. I let it flash for a couple of minutes before sticking it to the underside of the dash...

After that, I wiped off any excess epoxy in the grill opening and did my final assembly for the speaker mounts. I'll seal off the holes for the wires on my next day working on the truck.

The bottom two pictures show the final assembly bolted into place. One is from the bottom and the second one is the best side-view photo I could take...

[par4tom]

And here is the final product from the top view. All in all, this project took me less than an hour and half from start to finish...and you can modify what I did very easily by changing the size cutout for your speakers. But the best part is this...if you ever change your mind and want to do something different, you don't have to tear up your dash or cut a bunch of sheet metal...

[Andy4639]

Pretty cool man. Never thought about using the PVC for the backside! very cool!

[chevyrestoguy]

I like this idea! No drilling of the dash and it looks 100% stealthy.

On the hook-ups, do you separate the left and right CDTs, or do they run together kind of like a center channel speaker for your TV?

I'm really interested to see what you've got in mind for the rest of the speakers. I know that putting the mids in the doors is the optimum location, but I just can't bring myself to cut my doors. I still like to use the fresh air ducts in the kick panels, so removing those are out, too. I'm considering using a shallow depth mid and making a surface mount box, but then I can't take advantage of the air space inside the door.

I like high-end sound, so this thread is going to be very informative!

[RetroMfgWil]

Thats some clean work...

Just an FYI: there are Dual voice Coil speakers now available out there to get the Stereo output for cars that used to only have a mono speaker setup. Its an option if you don't want to do a whole custom setup like this. Its an easy bolt on and you can choose from 4x10s, 4x8, 6x9, 5x7 or a 6.5"

[par4tom]

Here's a couple more photos of my center channel setup.

The crossover includes 6 settings and a seperate volume control to use during setup. The crossover takes both left and right channel inputs from my Zapco 4 channel...

[par4tom]

And here's the box for the speakers.

[darqnez]

Great choice in speakers! CDT makes some good stuff, I have quite a bit of it, also the worksmanship here is stellar!

[par4tom]

I had heard these speakers back in about 2004 at CES show, and because I had had the opportunity while working at Zapco to see all of the cars, their CDT car stood out in particular. As I mentioned, I'm an audiophile type of guy and these were very exceptional.

I have not done a system in the past quite this way so I am eager to get started. Hope to update this soon.
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[king-918]

Cool thread

[tdangle]

I did something very similar in my 1970 truck, which worked great until I fixed up the AC ducts and hoses. Now my speaker setup no longer fits due to clearance issues.

[par4tom]

I'm moving forward a bit on my stereo system now as the truck is getting closer and closer to being finished. All of the mechanical is done and the wheels and tires are being ordered today.

Here are some photos of the accent-fills that CDT Audio has engineered. These are a very specialty driver, with an extremely high crossover point of about 8khz. Each tweeter is pointed directly at the center channel drivers and the intent is to pull the "stage heighth" up over the top of the dash and stabalize it over the center channel.

For the laymen on here, in competition systems, one of the key factors in having a winning system is for the stereo system to create an illusion for the judge that he/she is at a live performance and that the performers are directly in front of them and at or above eye level.

In serious sound quality systems, competitors use all kinds of tricks to do this. However it is done, the objective is to have a sound that appears to originate over the top-center of the dash and is stabile over the top center of the dash. This means, that when listening to critical sound tracks, that the vocals from the lead vocalist don't shift to the left or right side. This is much easier said then done when dealing with phase issues and accoustics in an automotive environment.

In simplest terms, the system I am building is designed to have imaging up over the top of the dash and squarely in the center. This is why I am using this center channel setup with the tweeters mounted high in the A pillars and aimed directly at the center channel...

Here are some pics of this process. I'll cover over these little pods once I get to installing the headliner...

Here is the A pillar after cutting a 2" hole

[par4tom]

Here is the tweeter cup I'll be using. I wrapped this with blue masking tape about 20 times so as to give me enough clearance for the headliner material once I go to mount everything up for the final time...

[par4tom]

The next three photos are just me roughing in the tweeter pod. I use Rage Gold and just a bit of Duraglass mixed in at about a 1:1 ratio...

The first photo is with 40 grit paper (I use this to rough in my shapes as the cheese grater won't fit into these small spaces.

The second photo is at 120 grit...

And the last photo is with the tweeter cup test fitted...I'll final sand this at 120 grit to work out any imperfections. I'll be covering this with an 1/8 closed polycell foam plus material...so I don't sand beyond 120. Plus, with 120 grit, it gives the glue a bit of edge to grab onto...

[par4tom]

Here's my sub enclosure rough in. I am going to be using 2 CDT Audio 8" subs behind the seat.

I always get the questions when doing high-end systems why I use such small subs.

Without getting too technical, small enclosures demand small drivers. And yes...I have heard all the arguments about 10", 12" and 15" drivers working well in small enclosures...and I have done many of these types of systems.

What I like about the smaller drivers is simply the speed and impact the bass notes. I'm not trying to shake the entire block, just get good, fast, tight hard hitting subs that are extremely fast and accurate. This also requires an amp with adequate damping.

Plus...I have a lot of audio gear to fit behind the seat and in building out the enclosures themselves, I was able to get about .375 cubic feet for each enclosure. When you figure about 25% deduction in air space for the magnet and motor structure of the driver, this is just about perfect at .25 cubic feet. And this is exactly what the manufacturer is calling for...

Here is the first enclosure design...I am using 1/2 mdf for the frame and backspace to conserve space, but using 3/4 inch mdf for the faceplate to ensure it stays rigid. I actually scrapped this enclosure as I always seem to screw up the first one and get the second one better. But anyway, you get the idea.

[par4tom]

Here is a mock up of the two sub enclosures and the amp rack...

[par4tom]

One of my objectives, is to get the sub enclosure and the amp rack to fit behind the lip of sheet metal at the back of the cab. This way, I can run the trim plate onto the rear of the cab and butt the upholstery up to the trim plate...here is my super sophisticated cardboard cutouts in order to create the template...below that is the first draft of the trim plate. I will probably go through 3 or 4 designs on this as I'm not sure exactly how I plan to mold this into the back of the cab...at least not yet.

I'm also 6-3...I want the seats to go all the way back.

[par4tom]

And here is my amp rack mock up with the 2 Zapco sl-z-400's and the 4 Zapco 1/3 Octave Eq's.

Why these amps and why so many 1/3 octaves?

Well, these amps were the best amps Zapco ever made in my opinion. These were manufactured in Modesto CA from about 1996 to 2000 and were the last of the Robert Zeff designs. They are extremely underated and are class A/B type amps. While not as efficient as a Class D amp of today, they are much faster and more musical than Class D amps because the outputs are tip 35/36 analog and not mosfets. Analog outputs much more expensive than mosfets, but they also use a lot of current. These two amps can pull up to 160 amps of current so I made sure to beef up my altenator. You can never have too much clean power in reserve!

Originally these amps were sold for about $1,600 each but since they are discontinued, I found them on ebay for about $250 bucks. Like all old amps, the capacitors inside start to dry out or leak when they have been stored for a long time. In fact, amps go bad faster from non-use than from use.

So, I sent them back to Zapco and had them rebuilt by my friend Mike Boronowski. My total cost in amps was about $900 but the performance in these things is downright scary. They make tons of power and are specifically designed for sound quality competition. Love these things and glad I could still find them.!

I am going to use one set of 1/3 octave eq's on the subs and another set on the mids and highs. This way, I can dial in a lot of mid-bass attack on the front sound stage and pull the sound stage more to the front of the truck without affecting the tuning on the subs.

The first picture shows the mock up. The second picture is where I covered the panel with trunk-liner material just to clean things up even though you won't be able to see it once I'm done with the trim plate around the amps and the neon lighting...

The third picture is where I am at as of today and fitting the middle jump seat to ensure clearance...Hope to get more work done next week but we'll see...I expect this project to take another 3 to 6 months...

T

[BR3W CITY]

Ugh this makes me miss my Zapco 2k MonoBloc
Class A comp amp, rated at over 2k watts and probably put out close to 3k. I could pound 4x15's all day off 2 optimas.

Sadly some crackhead stole it...So somewhere out there a dboy has a badass system courtesy of the black market.

[par4tom]

That 9.0 was a beast!!! 2000 watts continuous rms, sorry to hear it got stolen!