Monday, February 1, 2016

DIY - Experimental Open Baffle speakers (Part 1)

Since I now have a crippled pair of Pioneer S-D77 speakers at my disposal, I went thru my inventory of spare drivers to determine if any could be attached to the cabinets to get them going again.

Unfortunately none of the available drivers could not be mounted onto the cabinets as per original as the baffle cutouts were (again) just too small.

As the cabinets were glued together (no screws), it is very troublesome to attempt fitting the available parts from internally. Fitting them externally onto the cabinets would create a Frankenstein ... the boss will not approve!

I was considering salvaging the usable parts before disposing of the cabinets. It was then the idea hit me - why not convert them into an experimental Open Baffle speaker?? Always wondered how a pair of open baffle speakers would sound in my living room after hearing a pair of Gradient Helsinki at a local AV show couple years ago. LOVELY ... until they told me how much a pair costs!!!

Anyway... back to reality.

Planned steps of action are:-

1. Investigate available DIY open baffle (OB) designs on the net
    - Most the OB implementations on the net seem to be ground up implementations eg from scratch
    - These implementations have several common characteristics
      - baffle to house the drivers
      - some with, others without a base for bracing the baffle
      - wide unrestricted rear to maximise sound dispersion
      - OB kits seem to cost an arm and leg, even before shipping
      - minimal information on the crossovers deployed on most projects
        - need to test before we will know if a different crossover will be required for an OB?

2. Draw the desired outlines onto the existing cabinets
    - Since I have a jigsaw and sander handy, decided on a simple straight line cut-out of cabinets
    - Will retain only the baffle and the speaker connectors on the base

Cutting outlines for the cabinets on masking tape. LHS cabinet shows the rear, RHS cabinet shows the side
3. Remove all drivers and misc components from the internals. Ensure the misc cabling out of harm's way when jigsaw bites

Stock crossover on cabinet before the jigsaw bites
4. Jigsaw away the undesired portions of the cabinets*
    - Extract the stock crossover afterwards since originally fastened to the side of the cabinet
      - Tried unsuccessfully to remove the crossover before jigsawing
        - The enclosed cabinet makes for difficult DIY-ing

5. Sand away any sharp edges after the jigsaw is done*

*For those not living in Singapore, I need to explain the reason for delaying the metamorphosis. As I am one of the many Joe's residing in a government flat (just about 90% of the population), I can only create the mess in the external areas (with the all the accompanying din) during limited hours of the day and must cleanup afterwards. Would be an effort to do so after jigsawing and sanding the cabinets. Since the authorities do perform a wash-up of these external areas on a certain day of month, I should take advantage of this scheduled activity! Heh heh heh ....

6. Install the available pairs of tweeter and midrange units (same Ohms) onto the inside of the baffle
7. Reuse the original woofers
8. Reconnect all components to the correct wiring and polarity to the original crossover
9. Test the resultant OB