Rebuilding a Console Radio

[uzor]

Ok, this project has been a very long time in the making, but I'm finally at the point where I can get somewhere with it. This is going to be primarily a weekend project, so no guarantees on how speedy things will go.

Overview:

• Bought a Console Stereo at the local GoodWill
• Instead of "hiding" the mp3 server, let's celebrate it!
• Going to replace its current innards with a modern receiver and speakers
• Going to integrate a PC to act as a music (mp3/flac/CD's/whatever) server
• Going to try to keep it looking completely stock from the outside
• Will eventually have a touchscreen LCD under the lid for computer control

Let me fire up the Internet Wayback Machine to get you all caught up to the present.




Once upon a time, I started a thread to flesh out some ideas I had concerning a console radio I picked up at the GoodWill:

So I'm at the local GoodWill the other day and I see an old console radio (kinda like this one, but much less ugly). I picked it up for cheap to mod into an mp3 server. Basic idea is that instead of hiding the mp3 server in a corner and running it to something else, why not make it a centerpiece unto itself.

I have most of the computer pieces here already (scavenged from my heap), aside from an M-Audio Revo for the pc, but wanted some input on a few points. The built in speakers are utter crap. I plan on pulling the guts out of the sides and replacing them.

1. Should I build my own custom speakers/boxes to mount into the space, or should I buy something prebuilt that is about the right size and mod them into the space available?

2. If I do the former, how would I go about building speaker cabinets and what is good to drive them, or should I not try, and just buy some to put in (in that case, what would you all suggest)?

3. In either event, what should I use (receiver or otherwise) to drive the built in speakers? Keep in mind that this is just going to be used for music, not movies or anything, so I would think that 2.1 is the most I am going to need.


Things to consider:
- I am on a budget, so price is important.
- I want to keep the unit as self contained as possible (will mod a 15" lcd, touchpad and keyboard into the top compartment for I/O).
- Aside from some new paint, and new fabric to cover the speakers, I want to keep the unit looking stock.

Throughout the course of that thread I posted a few pictures:

(sorry in advance for the double post)

Here is the front of the unit with the top open. I will be replacing this top with one that opens all the way across the console, instead of having the split.

Here is what the speaker section looks like from the front. Yes, the fabric will be changing.

Here is an overall of the back.

Closeup of the left side.

Closeup of the right side.

And here's what's in the shelfy bit on the right side.

...and got some advise, which generally amounted to "we think it would be neat to build your own, but don't know enough to really help. Seek out the experts, they can be found at diyaudio.com.

 

[uzor]

So, more time passes, and I eventually register over at diyaudio, and start a thread there asking for help. That's really where the plans and concept got finalized into their current form, and what I based my audio gear purchasing decisions on. It's a good read for some additional background information, if you're interested. Throughout the course of that thread, I post some better pics of the stereo:

...I get the enclosure gutted of its previous contents:

...and I went through about three different plans for what to get and how to implement it. Did a bunch of math. Learned more about speakers and cabinet design than I ever thought I would. Dabbled in pro audio beiefly, learned their inner workings, before making some cardboard mock-ups:

Ok, after my initial mockup test-fit, it looks like I'm in for a bit more trouble than I had expected (but, hey - that's why I did the cardboard mockup in the first place).

Pics:

Working on construction of the speaker mockups. Note the shelf-turned-speaker template on the left.

A closer look at the shape (top down) of the left and right mains enclosures.

Shows left and right speaker mains installed and the receiver roughly placed in the middle section. Note that as the support brackets are still installed, all components are 3/4" farther out from the sides/front than they will be in the final build.

A closer, better view of the open area that the sub would have to fit into. Available dimensions are :
23" wide
15 3/8" high
9 1/2 " deep

My 10" sub won't fit in a traditional downfiring orientation. I'll post this info in the subwoofer forum and see if anyone has ideas on alternate drivers/orientations, etc., or if I need to scrap the subwoofer and re-evaluate my selections for the mains drivers.

For this mockup, I placed the receiver at the front of the unit so I could see the open area, but in the final design, the subwoofer (assuming I have one) will be at the front of the cabinet so as to allow me easy access to the receiver should I require it. A quick computation shows the internal volume available for the sub as 39.1 liters, with a probable max speaker diameter of 8" (unless I use some kind of funky angled mounting).

...sigh. Nothing's ever easy.

...which told me that I needed to change my plans yet again. I did a bit of figuring, and made my final choices on gear and how I was going to go about integrating everything:

Yeah, it looks bigger than it is to me too every time until I try to fit something in there. That's why I had the trouble I did with the subwoofer. I imagined that the receiver would take up a lot less room than it does.

As far as electronics under the lid goes, yes there will be electronics in there, just of a different variety. I haven't really played up this aspect of the build so far, though, as it wasn't directly relevant to what I've been looking for help on. In the "bolted-down" section to the right of the lid (that little cubby-hole like space), I'm going to be putting the guts of a computer (mobo on a tray that I drilled out of an old spare case, with an optical drive for CDs, HDD for digital media (mp3/flac/whatever), running on a basic WinXP install using foobar2000 or some such as the media player. The remainder of the open part under the lid will house two sets of things: The center section will have all the access controls for the "analog" audio (i.e. receiver face, subwoofer remote panel, etc.). The left section is going to house a touchscreen flat panel monitor that is going to serve as the head unit for the computer. The touchscreen aspect of it will allow me to use the monitor as keyboard, mouse, and monitor all rolled into one. This will be used to control/manipulate playlists and other digital media residing on the system.

In any event, on the audio front, I think that I'll probably be best served by sticking with the 10" Dayton RS sub, and just mounting it at an angle. From the response graphs I've been looking at in WinISD, I think that the drawback of having part of the speaker in a "corner" will be more than offset by the increase in audio quality over an 8" sub driver. See below for a crude ascii representation of a side view of the sub arrangement I'm talking about. As far as the mains goes, I will most likely be putting this up against a wall, so that kinda puts a damper on the open back/no enclosure idea. So, I'll stick with the 19L's I have mocked-up already. However, I wouldn't be opposed to swapping out the drivers for something that might be a bit more powerful while still working in the given situation. The Dayton classic 8's are only rated for 60W RMS, 85 peak, which is a bit under that of my receiver (85RMS, I think). I did look at the Dayton Reference Series as a possible upgrade to what we have earmarked now for the setup, but in looking at the ranges, it seems like I would almost be required to add a midrange to the mix in order to get a decent range at the crossover points (the 8" RS woofer tops out at 2kHz, and the RS tweeter bottoms out at that same 2kHz). If I do that however, that adds another 2 speakers to the mix and requires me to switch from 2-way to 3-way crossovers, and I don't know how much additional space that would all require.


Crude ascii sub design, side view (not to scale):

       ___________________
      |                  |
      |                  |
      |                  |
      |                  |
      |\                 |
      |   \ Speaker      |
      |      \ here      |
______|         \________|______
            ^
Open space to outside

...Made my purchases, just in time to score the plate amp I had been eying the whole time (which had been discontinued and restocked twice over this whole period).

So, with a plan, and product in hand (pics and a parts list coming soon), I'm back here to start my actual worklog.

 

[uzor]

Ok....here is my haul for the audio gear. PC components will be pulled from my existing surplus. When I get closer to doing that part of it, I'll post some pics of that stuff and maybe a parts list as well.

What you see here is:
1x - Onkyo TX-SR504 AV receiver (amplifier interface between computer and speakers)
1x - 250W Subwoofer Amplifier w/ Remote Control (amp for poundy bass)
2x - 8" Classic series Woofers by Dayton Audio (mains speakers)
2x - 1.5" Classic series shielded Tweeters by Dayton Audio (mains speakers)
1x - 10" Reference series High Fidelity Subwoofer by (you guessed it) Dayton Audio (sub for poundy bass)
2x - 2.5khz crossovers (splits highs and lows between the tweeters and woofers)
2x - 1lb bags Acousta-Stuf polyfill (goes in speaker enclosures, helps sound)
1x - 2" Precision Port (for the sub)
1x - 50' roll Speaker Gasket Tape (helps eliminate air leaks around speaker mount points)
1x - FREE SCREWDRIVER, (catalog and other goodies also included)

 

[oneil]

Wow, I can just imagine a modern/classic mix of looks with this thing... Go go mixing decks under the lifting panel!

 

[sandmanx]

As I said on irc, you are one lazy uzor!

 

[uzor]

As I said on irc, you are one lazy uzor!

Oh? How's that pinball machine coming?


...Anyways, I got my cut diagram blocked out and made a bit of progress on cutting sides for the mains enclosures last weekend. All of the speaker enclosures will be cut from a 4' x 8' sheet of MDF.

Cut diagram:

Here's my ever present helper:

The shelf that I ripped out and turned into quite the handy mock-up template and measure guide:

Making the first cut:

2 sets of sides for the mains:

Next up is going to be getting the tops and bottoms cut for the mains, and to get all pieces sanded to their final size.

 

[sandmanx]

Oh? How's that pinball machine coming?

I should make a thread for that. It would really help if I could find a forum so I knew what I was doing, rather than trying something, plugging it in, and see what happens. It makes for a long process.

 

[uzor]

Alright, I'm back. It's rained right before the weekend for the past two weeks. This means that my backyard/work area has been soggy and nearly unusable. Finally dried out enough this afternoon for me to get some work done. Got the tops and bottoms cut out, and did an initial dry fit on the cabinets for the mains.

They haven't been sanded to final size yet, so that's what's next - sand and fit all of these pieces so that everything fits nice and tight.

 

[Flash445]

This project looks quite interesting. Keep up the good work.

 

[tylerdustin2008]

Yea looks great so far, wish i had the extra money to do this.