Returning to Hapy Sounds - Part 2

I have spent some time improving the stereo set up in the bus when time has permitted. In a prior posting (See Returning to Hapy Sounds - Part 1), I described my effort to move the 5-1/4" speakers from the falling-apart door cards into small speaker boxes/pods constructed from a pair of schedule 40 4" pipe caps. These caps, now speaker pods, were attached to a removable piece of the vent system, so they are about knee-height and facing rearward. Today, I add another front speaker improvement.

Dash Speakers

image from FastFab

When these buses were first sold, there was a speaker mounted under the dashboard, pointing up at the windscreen, if you got the radio option. Regardless, the dash was constructed the same way, with perforations near the center of the dashboard top, a screw hole at the dash center-point near the windscreen and two mounting tabs underneath. While you could create something to hold a speaker, or a pair of speakers, leveraging the 2 tabs and the screw hole, a fabrication company already has. FastFab, based in La Hambra, CA, created a basic panel (product page here) into which a pair of 3-1/2" speakers can be mounted.

It should be noted, however, while the image on the product page, also appearing on the right, appears with rubber feet on the left side (which would fit into the mounting tabs), a mounting screw on the right side and speakers in-between... none of these are actually part of what you are buying. For $30US, you get a plain piece of bent metal with some holes bored into it. The product page does say that it does not include mounting hardware. However, in good faith, they could have included a picture of what you are actually getting. Simply, I was and remain unimpressed. I concluded it would probably take me more than an hour to make something similar and it probably wouldn't look as nice. I had it in-hand, so I moved forward with it.

3-1/2 Speakers

For speakers, I got a pair of 3-1/2 inch Kicker speakers. The model matches the 5-1/4 inch speakers I have mounted in the speaker pods I built in the last post, so the 3-1/2's should pair well. These cost me about $60US delivered, and they arrived with mounting hardware and wiring bits, but no grills. Since the dashboard has the perforations, and these speakers are going to mount inside the dash, grills are unnecessary. Crutchfield indicated on their website that these 3-1/2 speakers are an easy stock-swap replacement, where you re-use the stock grills, and that is why a grills are not delivered with the speakers.

I noticed that the panels had some sizing issues almost immediately after I started pairing the speakers with it. There are 2 misses: the mount holes, into which the black screws would ordinarily go to hold the speaker to the panel, are too large. So, the black screws which arrived with the 3-1/2 inch speakers could not be used. Second, the 2 large holes that the speakers are to set into are slightly too large. So, the speakers fit, but they shift around and will not sit cleanly without spending some time tweaking. When you combine these 2 design misses with the non-existent mounting bits, there is little actual value being delivered by these panels other than the bends and holes are in the right places.

Mount Speakers to Panel

speakers on panel

Unlike the picture on the product page, I chose to set my speakers through from the top, rather than suspend them from the bottom. This way, if one or more of the bolt/nut combinations fail, the speaker will not fall out of the panel. If I mounted it from below, loose fasteners could cause a speaker to drop out. Since the supplied black screws were not usable (panel holes too large), I found 4 gold-colored bolts in my home-electrical bin. These bolts had been for the copper grounding wire in electrical outlets. I had 4 nuts that fit, so away we go. As I mentioned earlier, getting the speakers to set just right them took some fiddling, but once they were set, and the bolt/nuts tightened, the panel was about ready for install. I like how the gold bolt heads match the gold centers of the speakers. In cases like this, it's better to be lucky than good. I added a couple of small pieces of foam on either side of the front mounting screw hole as well as on the mounting feet on the panel. This should reduce any vibration transmitting from the panel to the bus and vice versa. The foam on the feet became quite compressed from my use of clothespins to hold the foam in place, but they actually fit perfectly into the mounting tabs.

Dash Back to Black

Before I set the panel into the bus, I wanted to black-out the dash top. A prior owner had painted it gloss white, and that was the way it was when I bought Hapy. The glare on bright days was remarkable. So, when I replaced the windshield a few years ago due to age-related glazing, I painted the dash flat-grey like the rest of the interior of the bus. This was a considerable improvement, but there is a reason most cars have a black dash top: least daylight glare. I found a rattle-can of satin black in my garage, so after taping off the vinyl cover and the windshield seal, I shot what I could reach. There are areas that cannot be reached with a spray can, however: the vertical or nearly-vertical strips cannot be "seen" by the spray no matter the angle you hold the can. To get them color-consistent, I needed to hand-paint them with a short foam brush. This is kind of fun, actually. You can only see what you are doing through the windshield, so you blindly paint a little, run around to the front to see what you did and then repeat.

dash cover product image

I got to thinking about the noise in the bus, and how I want to reduce opportunities for sound to bounce off hard surfaces. The metal dash is a great example of one of those hard surfaces. So, after the painting efforts described above, I bought a DashCare dash cover. Knowing that the dash has contours to it, I paid the extra $5US for the faux suede, "DashSuede", rather than the standard thicker carpet model. This also "is low knap for a flat, low glare finish and will have high-low shading effects typical of Suede material". Once the sun returns, we'll see how "low glare" non-reflective it is. Since it has a thin foam core, it may help reduce reflected sound. I don't expect much, but every little bit helps. For now, this cover sits in a box, waiting for the projects to conclude.

Wire It Up

I stripped and prepped the wires before mounting the center panel. I figured I would have a hard enough time simply reaching the wires, and I was right. When I did the 5-1/4 speaker install, I knew I had these coming. So, I had spliced in a second stretch of speaker wire per speaker, so they were simply dangling when I brought the panel over. I simply routed the wire from the driver side under the dash and over the e-brake mechanics, dropping down into the passenger side foot well. In the picture on the right, here, I had the driver side wired in, using the passenger-side Sprinter seat as a work surface. Notice that the driver side is not installed yet. Still waiting... still waiting.

 

At this point, I had the wires and the speakers in a panel, so I simply I wired the speakers up: left -to- left, right-to-right. I suppose I could have tried to mix them up, but I didn't think there would be much left-right separation with the speakers so close together, so it didn't really matter. Either way, there are a pair of speakers pushing the left signal and a pair pushing the right. It is important to have all the speakers running on the same signal wiring to have the same resistance. Otherwise, sound levels will be inconsistent between them. By using the same manufacturer and the same series within that manufacturer, the sound will be as consistent as I could manage.

Mount Panel to Bus

Depending on how much crap you have under the center section of the dash of your bus, this could be anywhere from simple to very complicated. A few years ago, I had force-stuffed a rectangular plastic box into the original radio hole, and Hapy had some random wiring otherwise. I yanked the plastic box out, with a plan to do a better install later. Negotiating around the wires just took a ltitle patience. Once clear, the 2 feet set into the 2 mounting tabs towards the rear and the panel swings forward and up. I threaded a black screw that had delivered with the speakers through the hole in the dashboard and through the mount hole on the panel. I found that I had to start the threads on that screw first, and tighten down most of the way, before setting the feet. Otherwise the feet would pop off the little tabs. In fact, I got the front (front is front) screw almost all the way down and then swiveled the panel slightly to get the feet to set in the tabs. Then, I tightened that list little bit. As I wiggled the unit, there were no indications that the speakers were touching the underside of the dash.

 

Fire It Up

Once it was all put together, we were ready to test. As pronounced an improvement we realized when I moved the 5-1/4 speakers, adding the 3-1/2 speakers into the center of the dash was even more significant. The sound is very present now, with LOTS of mid and upper range, but the real test will be on the road with the noise of the engine, the drive-train, the traffic and the tires competing for our ears. Between the small 3-1/2" speakers and the very shallow pods for the 5-1/4" speakers, there was not as much bass as I like (I like a LOT of bass). I found that the head unit had reset while I had the power shut off, so the bass-boost was turned off during initial tests. Once I turned it back on and faded more signal to the rear, the bass came through and the bus is full of sound. Still, if you do something similar, it is reasonable to expect that the 3-1/2 speakers will push more high and mid than bass. I am looking forward to a road test to see if we lose the bass to road noise, forcing, perhaps, a sub into the mix.

That's it for today. Thanks, as always, for following along-

Returning to Hapy Sounds - Part 1

In the midst of the Summer 2019, I added the ability to listen to music to Hapy, the 1972 TDI-powered microbus (See Making Hapy Sounds Part 2, for example). Today, I start my revisit with the front speakers. In this part of the front speaker improvement, I create very very small speaker boxes for a pair of 5-1/4" speakers with materials readily available at the hardware store; remove the speakers from the door cards and mount them into those speaker boxes; and last, get it all into the bus. Unlike most of my posts, the overwhelming majority of the measurements are in inches rather than mm. This is because here in the US, all of the published material about speakers is in inches. So, any information I put here can be more easily cross-referenced.

Why?

Diablo Royale pod

I guess it makes sense to start with answering the question "why are you making a change". There are a couple of reasons. First, the door cards that I made out of pressed cardboard are starting to fail. Unlike the original cards, the material I used was not designed for this purpose. So, over time, as some moisture appeared (this is the Pacific NorthWest, after all), the cards started to bend, and pull away from the doors. With the 5-1/2" speakers mounted in the lower part of the card, the card condition deteriorated more quickly as the speaker added a swing-weight whenever the door was opened or closed. So, when the door was closed, the bottom of the card (and the speaker) were not mated to the door, allowing the speaker to kind of hang in space a little bit.

I decided to replace the pressed cardboard cards with a laser-cut PVC set from WerksBerg. These precision-cut PVC cards are great, and many options are available, but a pre-cut hole for speakers is not one of them. I decided that I didn't really want to cut the PVC. This leads to our second reason: while the sound was okay, it wasn't awesome and maybe it could be better while driving. The only real upside to the speakers being in the doors was the added sound we got in the music festival camping lot when we opened the passenger door. When driving around, there was music, but it lacked some clarity. Of course, the road, engine and wind noise contributed, but that's another whole story... and solution path for another day. I think speakers just hanging in space (back not enclosed) negatively impacted the quality of the sound, and the cards were not going to last much longer.

Options

schedule 40 4" cap

So, if the speakers are not going to be in the door, what other options are there? There are a few. Some folks cut holes in the toe kick. This brings the advantage of having speakers facing you, but they are still down by your feet. Some bus owners replace the little fresh air vents with little speakers. This option moves the sound closer to your ears, which is great, but you lose those vents, and the only speakers that fit in there are super small (like 2" tweeters).

If you have a parcel shelf under the dash, you can set/mount speakers in boxes placed on the shelf. The shelf narrows on the outer edges, so speakers most likely fit best near the center of the bus, near the central air pipe. I don't have those shelves, but even near the center they do not look terribly deep. When I first bought Hapy, a prior owner (PO) had mounted small boxed speakers to the big metal air vent boxes. They didn't work, and the PO had taken the stereo with him so I pitched those speakers. Of these options, I do prefer rear-facing / under-the-dash locations over the door cards. The trick will be figuring out how to mount them, and exactly where they will provide sound best.

5-1/4" Thinking

test fitting 5-1/4 speaker

So, we start with figuring out a way to mount / hang speakers under the dash such that they won't get damaged yet they fling sound towards us. The 5-1/4" round speakers I have are kinda large for the space. Sure, 6-1/2" round speakers are bigger, and more common, so finding a speaker box or pod that fits the 6.5 is definitely easier. Still, I have the 5-1/4's and the smaller footprint will play to my advantage now, since the new location will be inside the cab, potentially near our knees.

Ever seeking cheap, yet effective, solutions, I constructed one. But, of course, not without checking out off-the-shelf options:

• There is a guy (Diablo Royale) on eBay who makes plastic speaker pods in Texas. I bought a pair of his mounting pods for Oliver so I could mount the front speakers down by our feet, against the outer walls (See MGB Interior Panels - Part 1 or better yet MGB Gets Sound - Part 1). Diablo Royale had pods that fit 5-1/4" speakers, but they were still open-backed, $50US per pair and at least 6 inches across at the top by 4 inches deep. The base was at least 7 inches across. Looking at the under-dash, that would have been pretty ugly. Without a flush backwall, which would be nearly impossible with the contours up there, the sound would not throw as well. To make them fully enclosed / flush, I would have to construct a rear side.
• There are MDF speaker boxes, wrapped in trunk carpet. These are also larger, but at least they have a back. The smallest ones I saw for the 5-1/4" round speaker were 8 inches square (or larger as rectangles) and 5 inches deep. If I had a parcel shelf, they might fit, but really only in the center since those parcel shelves get shallow as these near the door A-pillar.

better view of a
metal bracket attempt

Those are basically your off-the-shelf options. For the space we are targeting, they are not terribly good. So, we get out of the (speaker) box, and see what we can come up with. Our requirements are few: the speaker requires a 4-1/2" hole to sit into -and- it needs just under 2 inches (1-13/16 inches) from the mounting surface to the rear of the "box" for the cone and magnet.

It turns out that a 4" schedule 40 PVC pipe cap is a great starting point for a speaker pod. The one I found is 2 inches deep from lip to rear wall, but I saw deeper ones on the 'net. The inner diameter is 4-1/2 inches. I know; you're asking "but you said 4 inch cap". Yes, that's right. The schedule 40 4" cap refers to the industry standard 4" pipe, which is an approximation of the inner diameter of the pipe. Since the cap goes around the outside of that pipe, there is additional diameter to account for the thickness of a schedule 40 PVC pipe (here's a link for more dimensions). Neat, eh? Oh, and these are about 1/2 the price of the Diablo Royale pods at less than $15US each, made-in-USA, they are available at your local hardware store -and- they have a back wall.

5-1/4" Speaker to Cap

Once in hand, we need to figure out how to mount the speaker to it, and then how to mount the unit into the bus. I started with the second question first by moving the speakers around while playing the stereo. I concluded that the farther to the outside I could put the speaker, the better the overall sound. I resolved with placement directly below the dash vents. To mount, I bore a pair of holes through the cap, and mounted the cap/pod to the metal vent cover. Since the vent cover could be removed and replaced, I could use bolt/nut /washer fasteners instead of self-tapping or sheet metal screws. I think the nut-bolt combination creates a better, more reliable attachment.

plastic mounting tabs

For mounting the speaker to the cap/pod, I started with the smallest angle brackets I could find at the local Ace hardware store (3/4") when I got the caps. I also tried 1/2" brackets but they were no better. I probably could have super-glued something plastic, but that seemed flimsy. After a lot of drilling, cutting measuring and more cutting, I abandoned the 3/4" angles. I tried 1/2" angles, but they did not line up right with the speaker cover holes. I bought a set of angles online that had a channel, but even the smallest set like these were too large. I even tried constructing mounts with some scrap wood (1/2" wide and thick by 3/4" tall), but they were too bulky.

 

So, how did I resolve it? In true ghetto style, of course. While cleaning up my garage, I found a lid for one of those larger rectangular plastic storage tubs. The lip bent around 90* and extended about 3/4". With tin snips, I cut a series of pieces out, each about 1/2" wide and at least 1/2" into the top of the lid. This produced 8 little plastic "L" shapes to construct mounts out of. I marked and drilled holes, and then cut away the excess material with the snips. They are barely visible now, and once I wrap the pods with trunk carpet of some other fabric, they will mostly disappear.

 

5-1/4" Pod Wiring

With the physical mounting solved, I turned to wire routing. Ideally, I would have included a wiring cup. I omitted it because the flat bottom of the cap/pod will be pressed against the bus for mounting. Then, I thought about putting a cup on the side. I figured between the curvature and the shallow space within, it simply wouldn't work. So, instead, I drilled a small hole in the side of the cap/pod, and sent the pair of speaker wires through it. Leaving some slack in the wires within the cap/pod, I applied a blob of caulk into the hole to seal it back up.

Polyfill?

polyfill'd

My last step was adding some polyfill into the cap/pod. Simply, polyfill interrupts the sound wave moving on the back-side of the speaker when sound is produced by the cone. This interruption improves the projected sound out of the front of the speaker, and tricks the speaker into acting like it is in a larger enclosure: so, more bass. Using polyfill (or not) is kind of a religion with audio folks. I figure speaker enclosure manufacturers wouldn't use it if it didn't do something beneficial, and the 6x9 boxes I got for Hapy's rear speakers were polyfill'd. This cap/pod thing is super small for this speaker, so if it was going to do anything for a small speaker, this is the kind of scenario where it might. Still, the probability that I would really notice is virtually 0 (especially in the while-driving din), but I did it anyway. Ultimately, this cap/pod is about creating a safe means of mounting the speaker, with a hope that the sound is improved through it's proximity to the listener. The sound could not be measurably worse by moving it a foot closer in an enclosed cap/pod -versus- hanging in a loose, flapping door card down by your feet. Quite the opposite, I think it is much better. At least, it is set up to be.

isolation foam

When I get around to making the interior nicer with carpet and other fabrics, I will cover the cap/pods with whatever material I am otherwise using along that front wall so they visually disappear. Or, I'll simply cover them with trunk carpet. Before final assembly, I put some closed cell foam between the speaker cap/pod and the vent cover I mounted it to. This should help isolate the sound / vibrations a little bit. You can see the foam in the picture on the right as well as the markings I made to get the speaker aligned for drilling the mounting holes. Last, I simply plugged the wires into the speakers, set the speaker into the cap/pod, set the grill atop and attached it to the brackets. I took the assembly out to the bus and simply re-attached the vent covers with the speakers attached. The wires dangling from the cup/pods were tied into the existing front speaker wires that used to be in the doors, and then tucked away. I may apply a wire wrap to disguise them a little better, but I think they look good enough for now.

Testing

wired up and fired up

Because of my lack of a warm workspace where the bus fits, and a young puppy who can't be out in the cold for more than 15 minutes at a time, I still have not completed the install of the replacement seats. So, testing consisted of playing the stereo without moving the bus. Still, I think moving the 5-1/4" speakers made a difference. Considering that our legs no longer interrupt the sound waves, the speakers are about a foot closer to our ears, and the speakers are contained, there should be some benefit. Ultimately, I probably didn't need to move the 5-1/4's for sound improvement. It is absolutely possible that the open space behind the speaker in the door cavity actually helps the lower frequency sound form better. But, I didn't want to cut the new cards and this was kinda fun, and this was something I could mostly do in a warm garage, with a puppy underfoot.

That's it for today. thanks, as always, for following along-

Making Hapy Sounds (Part 2)

Continuing on my post about putting some music into Hapy, today I will go through some if the fun of installing what I'm calling "version 1" of the fuller sound system into the microbus. At this point, I have a pile of components, a spool of speaker wire and a dream.

Front Speakers Physical Mounting
I really wanted to spare my door panels, but I could not figure out where the kick panels were supposed to go. So, I couldn't figure out how much space I had and where. I haven't had kick panels for years, and pictures on the interweb of them installed really didn't show how much backspace there was. Resigned, I went down the tried-and-true path of a door card installation. My cards were made of a thick MDF material rather than the waffle board that most cards are made of. I don't know if that's better or worse, it's just different. I believe the process would be the same regardless.

Since I am installing 5-1/4" speakers, the hole will be smaller than that. A quick look at the manufacturer's spec's tell me that I need a 4-1/2" diameter hole. We take a few measurements and determine that placing the center-point of the hole between 9 and 9-1/2 inches from the bottom of the door and 6 to 6-1/2 inches from the front. That would place the speaker entirely within the upside down trapezoid below the bottom of the window in the door. I picked 9-by-6 since that was easy to remember, and with a carpenters square marked the spot on the driver-side card. Then, I nabbed a compass from the kids school supplies, measured out a radius of 2-1/4" (radius = diameter/2) and marked the cut line on the card. Had I been less daring, I could have cut a piece of cardboard to match the shape of the lower door card and performed test-cuts on that until I had the location where I liked it. If you are using nice cards, I would encourage that.

I took the card, then, out of the bus, and tried to visualize how the hole would align with the trapezoid. It seemed right, so I set the card down, drilled a hole near the line and finished the hole cut-out with a hand drywall saw (it is straight and cuts as you push away rather than as you pull towards). Once cut, I cleaned the edge with a file. I have this knack of undercutting, leaving myself lots of edge cleaning, and this was another one of those. So, I had to file just to get the hole up to the line, and then clean it up. Once I was able to set the speaker in the hole, I test-fit the card. The hole was inside the trapezoid, but is was fairly front-ward as you can see in the picture to the right. I don't think it really matters so long as the hole is wholly inside the upside down trapezoid. I removed the card, set the speaker in and test fit again. Nothing speaker-related was touching anything other than the card. We had a winner. I transferred the hole placement onto the passenger door card, drilled, cut and shaped it until a speaker would fit and test fit the passenger side the same way.

They looked good. So, I checked to get the speaker top level, marked and started the mount holes. I set the speaker grill on and sent the screws through the grill and the speaker mount holes and on through the card until they were snug. I may swap out the screws for bolts with washers and locknuts (on the backside) in a future version. There's just something about depending upon the threads of a screw to hold speakers to a door card that just seems hinky.

Front Speaker Wiring
One of the reasons I didn't want to put speakers in the doors is the question of how to route the speaker wires. I've seen wiring jobs where the wires don't pass through the front edge of the door, rather they pass from between the card and the door, making a small loop of wire when the door shuts. I didn't want that. Fortunately, I had pulled the door light switches out of the A-pillars a few years ago to paint and never returned them (since they didn't do anything anyway). This put a square hole in the A-pillar. I didn't want to drill a hole in the door, and I didn't have to. There are vents along that edge. So, threading wire from the spool back from the front, the wires passed through the door light switch hole, up through a vent high in the front edge of the door, down the front channel in the door and below the support. I left myself about a foot of wire to which I attached the pigtail that came with the speakers. Then, it was a simple matter to plug the clips into the speakers and then re-install the door cards. The other end of the speaker wire was routed up over the air vents and dashboard supports, and routed over to the hole where the head unit usually would go, leaving them dangling.

Rear Speaker Physical Mounting
I loaded the 6x9 speaker boxes with 6x9 speakers, so the physical mounting was fairly routine, in that respect: wire the supplied wires in the box to the pigtails, plug the pigtails into the speakers, place the speakers in the hole, put on the grills, thread the screws through. Since the boxes are going to kind of float around for now, there isn't much else to do mounting-wise, though that may change as we drive around and discover what we need for locating them for sound as well as whether they need to be a-fixed for travel.

Rear Speaker Wiring
Back when I had run a bunch of wires from the rear of the bus, I bore a hole in the wall behind the drivers seat. I ran a pair of speaker wires through that hole back past the old fridge-turned-storage-cabinet (See From Fridge to Storage). From there, they ran along the floor with the other wires, up behind the air vents (and where the kick panels would be), over the dash supports to the general stereo area. I added some plugs to the wires leading to the speakers so they can be unplugged and the speakerbox can be plugged in. I set the speakers on the rock-n-roll bed and shifted to setting up the head unit.

As always seems to be the case, this got long again. To be fair, I was probably 4 or 5 hours into the work at this point, so it's not like I'm just spinning a big tale out of a tiny effort or anything. Anyway, I'll pick this up next week. Thanks as always, for following along-