Archive for the ‘90+lbs’ Category

Smooth Smith Audio – 312c

April 29, 2017 Leave a comment


Designed by Eric “Smooth” Smith

Design Goals:

  • Hybrid as mixing monitors and entertainment system
  • Partially mobile/ Easy to fit in smaller spaces
  • Flat frequency response with variable low end
  • Budget: $2500

Key Features:

  • F3 of 28Hz
  • Sealed enclosure
  • +/- 1 dB from 150Hz to 20kHz
  • +/- 2 dB from 30Hz to 150Hz
  • MiniDSP active crossover @ 130 Hz, passive crossover at 3.5kHz
  • 1/2″ MDF, 1/2″ Cherry MDF


  • Eton 25SD-1 1″ Soft Dome Tweeter
  • Dayton Audio RS150P-4 6″ Paper Cone Woofer
  • Dayton Audio RSS315HF-4 12″ Aluminum Cone Woofer


Frequency Response:


F - 60

Integrated Frequency Response:

F IntOff-Axis Response

F - Horizontal Off-Axis

Harmonic Distortion

F - Harm Dist

Rear Sub-woofer Connection



Sandcastle 7.2


Designed by: Eric Bartos


  • 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


  • 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 Overall 60db range

Surround Integrated Response

surround integrated 40

Center Speaker

center response 60.png

Center Integrated Response

center integrated 40


sub response 60

Sandcastle glossy

Sandcastle Research Paper

Sandcastle Final Testing

TW-84 Home Entertainment Speakers

April 29, 2016 Leave a comment

TW-84 Pic

Design Goals

  • Pleasurable
  • Fairly Flat Frequency Response
  • Passive Crossover
  • Ported Enclosure For Increased Low End
  • Pair With External Subwoofer
  • Sound Good Alone As Well

Key Features 

  • WxDxH = 1′ x 1′ 3/8″ x 3′ 9 1/2″
  • +/- 2dB from 40-20,000Hz
  • 2 Way Design
  • F3 of 37 Hz


  • Scanspeak D2604/32000
  • Dayton Audio RS225


Frequency Response



Design & Final Testing Report


TPA-1000 Home Theater Speakers


Design By:

Paul Bristol

Key dseatures

  • Tall, Slender Design
  • F3 of 48Hz
  • +/- 3dB response from 100 Hz-20 kHz
  • For Use with External Sub
  • Large Stereo Image/ Wide Dispersion


  • Woofers: Seas Prestige L16N-SL 6” Woofer
  • Tweeter: Eton 25SD-1 1” Soft Dome Tweeter

Frequency Response

Screen Shot 2015-04-30 at 9.52.37 PM

Integrated Frequency Response

Screen Shot 2015-04-30 at 9.57.46 PM

Horizontal Off Axis

Screen Shot 2015-04-30 at 10.42.38 PM

TPA-1000 Speaker Glossy

Design and Testing

TPA-1000 Final Drafting

Aeternus Lux 2.2 Modular System

May 11, 2013 1 comment

Design and Construction:

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Paul Kirby

Design Goals

  • Portable
  • Low Fatigue
  • Low bass extension
  • Modular
  • Good horizontal Off-axis
  • Eventual use in 5.1 system

Key Features 

  • Large Size WxDxH = 9″x1’2″x4’10”
  • +/- 1.5dB from 75-20,000Hz
  • MTM Design
  • Inset tweeter for minimal distance between woofers, hence minimal vertical lobbing
  • Side-firing subwoofer modules (f3 of 25Hz)
  • Removable main with f3 of 70Hz
  • +/- 1.5dB from 75-20,000Hz
  • Active to passive cascaded crossover for module implementation


  • Morel MDT30S-4 1″ Textile Dome Tweeter
  • SEAS Prestige L15RLY/P (H1141) 5.5″ Aluminum Cone Woofers
  • SB Acoustics SB29SWNRK-S75 10″ Subwoofer

Main Response (green is port measurement)

Integrated Response

Sub Response

Sub Response

Impulse Response

Impulse Response


Design Report and Final Testing

Aeternus Lux Drafting


Raving Behemoths


Designed, Built, and Tested by Nathan Hunter

Design Goals

  • High Output
  • improved Horizontal Off-Axis Response
  • Low Frequency Extension with ƒ3 ≈ 50 Hz
  • Voicing to include Bass Boost
  • Low cost comparing to PA Speakers with similar capabilities

Features and Components

  • Diamond Shape with Rugged Exterior
  • Floor Mounting
  • Active Digital Crossover PCS 2.400
  • Selenium Pro D220Ti Horn Driver
  • Selenium Pro HC23-25 Exponential Waveguide
  • 2x Dayton Audio PA301-8 12″ Woofers
  • Carvin Cabinet Handles for easier mobility

Weight Vs. Similar Products

  • Raving Behemoths ≈ 150 lbs
  • JBL PRX612M = 34.5 lbs
  • QSC KW122 = 49 lbs

Cost Vs. Similar Products

  • Raving Behemoths ≈ $1300
  • JBL PRX612M List Price = $1299
  • QSC KW122 List Price = $1399

Testing Results









April 29, 2012 Leave a comment


I set out to create critical listening speakers that will be enjoyable in any room you put them in. This was accomplished by creating a floor standing pair of speakers with great off axis response to make the largest “sweet spot” to fully enjoy your music. I believe speakers should be flexible enough to be an afterthought when you are relaxing to your favorite music.

Epimetheus utilizes a passive 2.5-way crossover design which means, compared to a 2-way crossover, there is an additional woofer that handles only the bass frequency.


+/- 2 dB from 70 to 17k Hz

Great Off Axis Response

Under $800

Floor standing

F3: 60 Hz


Tweeter: The Morel MDT29 was selected for it’s good off axis performance, and low frequency extension that allows it to be crossed over around 1800 Hz

Woofer: The Seas L16RN-SL was selected because its Q(tc) indicated it was suited for a sealed box, plus it has good low frequency extension for its size.


Testing Report

Crossover Schematic


Testing Results:

Full Range

Purple: Full Range, Red: Tweeter, Blue: Mid-Woofer, Green: .5 Woofer

Full Range, Mid Woofer Inverted

Horizontal Off Axis Response

Purple: 0º, Red:15º, Green: 30º, Blue: 45º, Orange: 60º

Vertical Off Axis Response

Purple: 0º, Red:15º, Green: 30º, Blue: 45º, Orange: 60º

Harmonic Distortion:

Step Response: 

Impulse Response:

Minimum Phase Response:


Tweeter Response:

Woofer Response:

Creative Commons License

Epimetheus by Russell Goddard is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.