Sandcastle 7.2

Designed by: Eric Bartos

Goals

• 7.2 surround sound system for enjoyment and the occasional mix
• +/- 4dB response
• active crossover

Key Features

• F3 of 38Hz on surround speakers (before crossover between subwoofer)
• F3 of 34Hz on center speaker (before crossover between subwoofer)
• F3 of 24Hz on subwoofers
• +/- 4dB from 50Hz to 21kHz on surround speakers
• +/- 4dB from 47Hz to 21kHz on center speaker
• +/- 2dB from 25Hz to 200Hz on subwoofer
• center speaker has active/passive crossover system
• 1/2″ birch ply and 1/2″ MDF construction for center speaker and surround speakers
• 1/2″ birch ply and 3/4″ MDF construction for subwoofers
• BSS Blu-100 & BSS Blu-BoB for DSP

Drivers

• Woofer: Dayton Audio RS225-8
• Tweeter: Seas Prestige 19TFF1
• Midrange (Center speaker only): Dayton Audio RS52AN-8
• Subwoofer: Eminence LAB12-C

Frequency Response

Surround speakers

Surround Integrated Response

Center Speaker

Center Integrated Response

Subwoofer

Sandcastle glossy

Sandcastle Research Paper

Sandcastle Final Testing

JH Array

Introduction

Designing speakers is a battle of the minds. This battle can prove to be long and drawn out but when you reach the end it is very rewarding. There are so many different designs that can be implemented it is very challenging to select something and stick with it. As I have found out you can have a design and then see another design and immediately want to incorporate or change to the new design. I relate it to a kid in a candy store. The kid has his eye set on a jaw breaker going in but when all is said and done he walks out with a giant gummy bear. As long as the end product fully satisfies what you want it to than you have completed the mission.

Design Goals

The design for the JH Array came from a line array system. Working in live sound thats just about all you see and hear now. So I wanted to take what I listen to at work and make is sound better, look cooler and hang in my living room. In order to make them sound better I used quality drivers as well as solid box construction in order to get the sound I wanted. In order to make them look cooler I decided to go with a satin black center and bare wood sides this gave it contrast and some warmth that line arrays lack. Finally hanging in myliving room. I designed both boxes with anchor points so that it is possible for me to put some eye bolts into them and hang them from any rig point.

Features

• All sealed boxes to provide good transient response
• MTM speaker layout to provide good off axis listening
• Frequency Response +/- 3dB

Drivers

• Tweeter: ScanSpeak Illuminator D3004, 1” Soft dome
• Mid Range: Peerless HDS 830883 6 1/2”, Nomex diaphragm
• Subwoofer:TC Sounds Epic 12” DVC Subwoofer

Box Construction

• Boxes built using constrained layer construction

• Mid & Tweeter Box (outside going in)
  • 1) 1/2” Birch Ply(top, bottom, front and back)
    • 3/4” Baltic Birch(Sides)
  • 2) 3/4” MDF
  • 3) 1/8” Mass loaded vinyl
  • 4) 1/8” Masonite

• Sub box
  • 1) 1/2” Birch Ply(top, bottom, front and back)
    • 3/4” Baltic Birch(Sides)
  • 2) 3/4” MDF

• Rounded Sides
• Screws only visible in the rear
• Magnets in baffle for grills \
• Sub bracing also supports voice coil

Final Results

Frequency Response

Horizontal Off Axis

Vertical Off Axis

Left Right Difference

Waterfall

Tweeter

Frequency Response

Horizontal Off Axis

Vertical Off Axis

Impulse

 

Mid Range

Frequency Response

Horizontal Off Axis

Vertical Off Axis

Impulse

Sub Woofer

Frequency Response

Horizontal Off Axis

Vertical Off Axis

Impulse

Crossover Response

Documents

Design Proposal

Testing Report

Enclosure Drafting

Crossover Design