Tercet Towers

Tercet Towers

Jim O

Project Category:
Tower Speakers

Project Level:

Project Time:
20+ Hours

Project Cost:
$500 – $1,000

Project Description:
Audiophile floor towers.

Design Goals:
To design and build a 3 way tower system using a 1st order crossover design with high power capabilities. To be driven with a stereo pre-amp and a 125 watt per channel amp. No EQ running totally flat.

Driver Selection:
275-131 Dayton Audio RST28A-4 1-1/8″ Reference Series Aluminum Dome Tweeter 4 Ohm

295-528 Dayton Audio DSA175-8 6-1/2″ Designer Series Aluminum Cone Woofer

295-357 Dayton Audio RS270-8 10″ Reference Woofer

Enclosure Design:
3 separate cabinets stacked to make a tower using bass reflex designs that are angled to help improve time alignment and audio focus.

Enclosure Assembly:
Poplar fronts, tops and bottoms. MDF sides and backs, webs and gussets. I made 3D models for several of the parts and a friend printed them for me on his 3D printer.

Crossover Design:
1st order crossover with zobel network on the mid bass. As well as a frequency overlap between the bass and mid bass drivers. This was done using XSIM.

Tips & Tricks:
The fronts, tops and bottoms are stained with Barn Red polyurethane stain with a polyurethane clear coat. The sides and back have flat black exterior latex using a roller to apply.

This requires 3D printed parts to complete as shown. I have the STL files I created for printing the plastic parts, but they exceed the 1.5 meg file limit here.

About the Designer:
I am a retired aircraft composite tool builder and now an amateur speaker designer/builder for my home stereos. I’m still learning (hopefully).

Project Parts List:

Dayton Audio RST28A-4 1-1/8″ Reference Series Aluminum Dome Tweeter 4 Ohm
Dayton Audio DSA175-8 6-1/2″ Designer Series Aluminum Cone Woofer
Dayton Audio RS270-8 10″ Reference Woofer
ERSE 2.5mH 18 AWG Perfect Layer Inductor Crossover Coil
Jantzen Audio 0.25mH 15 AWG Air Core Inductor Crossover Coil
Dayton Audio DMPC-8.2 8.2uF 250V Polypropylene Capacitor
Audyn Cap Q4 82uF 400V MKP Metalized Polypropylene Foil Crossover Capacitor
Jantzen Audio 33.00 Ohm 10 Watt Audio-Grade Superes Resistor
Mills 7 Ohm 12W Non-Inductive Resistor
Solen 16uF 400V Polypropylene Capacitor
Parts Express Recessed Binding Post Banana Jack 5-Way Speaker Wire Terminal
4″ ABS tubing for bottom firing ports on the lower cabinets


Add yours
  1. 1

    Wow… I think you have succeeded in your chosen “hobby” these are awesome! These look as good as any I have seen in a upper level showroom. Great job!

    • 3
      Jim Ohmart

      I’m sorry there is no thread. I probably should have done a better job of documenting my work. I have a couple more projects in the works and hopefully will get them accomplished this year. I’ll try and get a better step by step process show. Thanks Jim O.

    • 4
      Jim O

      Sorry for the delayed response. There is no thread. All the info I could submit I did. The STL files for use in 3D printing of the printed parts are too large per PE’s limit to upload.

  2. 5
    Jim Ohmart

    Marc, the info on this page is all I’ve provided. The STL files to use for slicing and 3D printing are to large to be submitted seeing there is a file size limitation on PE’s site. I’m not sure if there is a way through PE to make email contact so that I could provide you with more info etc.
    Jim O

  3. 6
    Marc-André Clément

    Jim. Your answers dont appear here for some reason but i’ll answer anyway. Truth is I would not need plans, your images are clear enough. I would have liked a build thread just because i love them. Speaker porn.
    Too bad we can’t upload files, i would have liked to try them out. I need a project. Anyway excellent job.

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