2 Way Towers With Built-In Subwoofers

2 Way Towers With Built-In Subwoofers


 

Designer:
Jim O

Project Category:
Tower Speakers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
$500 – $1,000

Project Description:
2 way towers with active subwoofer incorporated.

Design Goals:
To build a small fairly low cost, but potent 2 way speaker system with subwoofer assist.

Driver Selection:
Dayton Audio NHP25Ti-4 1″ Titanium Dome High Power Neodymium Tweeter 4 Ohm 275-109
Goldwood GW-S650/8 6-1/2″ Poly Cone Woofer 8 Ohm 290-309
Dayton Audio DA175-8 7″ Aluminum Cone Woofer 295-335

Enclosure Design:
Bass reflex towers with rear slotted ports for upper section 2 way drivers and for the lower subwoofer section.

Enclosure Assembly:
The enclosure consists of 3/4″ MDF with a poplar front baffle.

Crossover Design:
2 way crossover designed using XSIM and PE parts.

Tips & Tricks:
I have found it works best to cut the front baffle a little larger than the front of the box and use a edge trim bit with a router to clean up. That way the front baffle fits the box perfectly. You can round-over upper and lower side corners as desired up to 3/4″ radius. I used a 3/8″ radius round-over bit for this build.

Conclusion:
Both upper and lower section boxes are tuned to 35 Hz and with no eq have a wide frequency response with very respectable low end.

About the Designer:
I am a retired aircraft composite tool builder and now an amateur speaker designer/builder hobbyist for my home stereos.

Project Parts List:

Dayton Audio NHP25Ti-4 1″ Titanium Dome High Power Neodymium Tweeter 4 Ohm
Goldwood GW-S650/8 6-1/2″ Poly Cone Woofer 8 Ohm
Dayton Audio DA175-8 7″ Aluminum Cone Woofer
Parts Express Gold Plated Bi-Amp Speaker Wire Terminal Cup Binding Post Banana Jack
Dayton Audio DNR-1.0 1 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-0.51 0.51 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-3.0 3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-7.0 7 Ohm 10W Precision Audio Grade Resistor
Jantzen Audio 33.00 Ohm 10 Watt Audio-Grade Superes Resistor
1.5uF 100V Electrolytic Non-Polarized Crossover Capacitor
3.3uF 100V Electrolytic Non-Polarized Crossover Capacitor
4.0uF 100V Electrolytic Non-Polarized Crossover Capacitor
Dayton Audio 0.27mH 18 AWG Perfect Layer Inductor Crossover Coil
Audtek 16 AWG OFC Speaker Wire 100 ft.

Other Items Used:
4 X 8 MDF sheet
1 X 10 poplar board
Pre-stain for poly urethane, poly urethane stain, poly urethane clear coat and black exterior latex paint
Polyfill
Outboard subwoofer amp driven with stereo amp high level out

7 Comments

Add yours
  1. 1
    Thom

    Great looking design and speakers I would be very happy to own a set! So… an aircraft composite tool builder. Did you ever work in Pico Rivera CA by any chance? Thanks for putting this up.

    • 2
      Jim O

      No I worked in Wichita before losing my job after 34 years seeing the company went bankrupt. I contracted for a year then went direct at another local aircraft company for a few years before retiring. I happy with the overall outcome of the project. Of course there could be few upgrades like putting in peerless or arum cantus drivers for the subs and using all high end crossover components, but bang for the buck was the goal. The speakers are starting to break-in and sound better every time I use them. Now on to the next project.

    • 4
      Jim O

      The subs sections are the lower parts of the cabinets which house the Goldwood speakers. They are driven by an outboard sub amp with the crossover dialed in at 80Hz. Both upper and lower sections are tuned to 35Hz. You’d be surprised and the low end response they produce. It definitely thickens the bottom end. This was a bang for the buck project and a higher end driver selection for the subs sections along with more costly crossover parts for the upper 2 way sections would be nice, but that wasn’t the goal. For around $600 sub amp and all they’re pretty sweet. Thanks for your input.

    • 6
      Jim O

      Sorry for the delayed response. I’m using a PE stereo tube amp to drive the upper sections and it has a full range sub out. So, I added a rolls electronic crossover and send lower frequencies to a Yamaha 85 watt per stereo amp to drive the sub sections of the cabs.

  2. 7
    Jim Ohmart

    I’m using a yamaha 85 watts a channel amp with a rolls electronic crossover to drive the lower section drivers. And they will fill the room nicely. Sorry I haven’t responded sooner, but I haven’t visited the project section of the site for a while.
    Jim O.

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