Project Category:
Bookshelf Speakers

Project Level:

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Classic 10″ Retro Design
To me there’s just something Magic about a well designed, large woofer 2 Way speaker. Understanding the problems of meshing a large paper Woofer and small non loaded Tweeter into a flat accurate speaker system, I can see why there’s not to many being made today. But with the more advanced drivers and crossover technology available today, I thought I’d revisit some old memories. I like a challenge and it seems no one designing speakers like this anymore, I figured I’d give it a shot.

Design Goals:
To reproduce the speakers I Loved in my teens with a modern drivers and crossover design. I figure I could do at least as good as my old Realistic Optimus 23s I settled with, since I couldn’t afford the Dynaco a25s I lusted after or the JBL L56s.

Driver Selection:
295-315 Dayton Audio DC250-8 10″ Classic Woofer
275-070 Dayton Audio DC28F-8 1-1/8″ Silk Dome Tweeter

Enclosure Design:
Large Bookshelf Ported design.
I decided to try to copy the drivers and cabinet dimensions of those old Realistic Speakers. Dimensions are 22.25″x 12.25″x 11.75″ Internal enclosure volume of 1.3 is a little small for the 10″ woofer but still goes quite low with the DC250-8 and 3″ port facing forward. I’m solid and fast too, down to 40Hz.

Enclosure Assembly:
Particle Board, Red Oak Veneer/White Maple
Using the materiel of choice during the 80’s-90’s, I’ve been doing my measurements accounting for the sound of the box. Minimal bracing used. I think the cabinet is part of the presentation. It gives a speaker character and a signature.

Crossover Design:
The woofer uses a 2nd order filter with a notch capacitor across the coil. While using resistors in the load for contouring the woofer’s response and maintaining a flat impedance. I used 2 high powered ceramic/sand wire-wound paralleled for increased power handling. The tweeter filter is a simple 2nd order with padding resistor dropping the tweeter down to match the woofer.

Dayton makes great Drivers, I usually buy nothing else for my original designs. The Dayton Audio DC250-8 10″ Classic Woofer is a great driver to work with, solid and clean bass, and a good sounding mid-range to at least 2kHz. The Dayton Audio DC28F-8 1-1/8″ Silk Dome Tweeter is an over-achiever. It’s an amazing value and sounds like it cost many times more than it sells for.
I was able to put the 2 drivers together with a solid response, excellent imaging and powerful bass in a classic looking speaker that’s way better than those in the 70’s and 80’s. I’ve made a few sets of these now, and my customers and I are very pleased with the results.

About the Designer:
I’ve been in the Audio/Video and Electronics Security Business for a long time. Building custom home theater rooms and set up, led me to building custom speakers for a few of my clients. Though I’ve always been a Speaker DIYer since my early days at the local Radio Shack and using the drivers they sold. Good Times!

Project Parts List:

Round Speaker Terminal Cup 4-1/8″ Satin Nickel Binding Post Banana Jack
Dayton Audio DMPC-18 18uF 250V Polypropylene Capacitor
Dayton Audio DNR-3.3 3.3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DMPC-1.5 1.5uF 250V Polypropylene Capacitor
Dayton Audio DMPC-10 10uF 250V Polypropylene Capacitor
40 Ohm 20W Resistor Wire Wound
Dayton Audio 0.33mH 18 AWG Perfect Layer Inductor Crossover Coil
Dayton Audio 2.5mH 18 AWG I Core Inductor Crossover Coil
Dayton Audio DC28F-8 1-1/8″ Silk Dome Tweeter
Dayton Audio DC250-8 10″ Classic Woofer


Add yours
  1. 5

    I have heard these speakers and I am very impressed with the sound! Enjoy listening to all types of music through these speakers.

  2. 9
    Jeremy Bourgoin

    Amazing Speakers, the sound that comes out of these Speakers is Insane, Rich Sound, quality Speakers at a great price. Enjoyed listening to them, Thank You!

  3. 12
    Christie Morrison

    Great work and attention to detail. Speakers sound great, way better than anything I’ve had, and way cheaper than the ones that sound worse!

  4. 17

    Very nice work on the cabs and the XO ! Always felt the DC 250 to be under appreciated and have used it for repairs. I’ve inherited a pair of Dynaco A 25 with blown woofers. Dropped in some DC 250 and was pleasently surprised We are using them for dance night in the shop. Any chance you’d have time to sim an XO for DC 250 and the stock large dome tweet ? I’ve got no files or mike but there’s lots of folks who would appreciate the effort. Thanks for your time

    • 18

      Thanks for the kind words, I worked hard on that shine, lol
      Sorry, 2 crossover schematics were downloaded. Guess i pushed too many buttons. It’s the one labelled E’couter of coarse, the other is a next version work in progress based on the RS series drivers. It’s gonna be Killer, lol
      The DC250-8 is a pretty nice looking/great sounding woofer and with the Dynaco’s proximate .5 CuFt internal volume cab, it’ll have a serious bump in the fun bass regions. I’m sure it sounds great, and the aperiodic cabinet should extend the low end a bit and lower resonances. I wish I had the original Seas 87H tweeter to measure, I’d be glad to work up a crossover for you. If you get files or of the Dynaco tweeter let me know. I searched for 2 hours, no one is posting any graphs. Maybe I’ll finally find me a pair of those Dynaco’s and do my own.
      My crossover design had similar goals as the A25’s, but with modern drivers. The DC250-8 has good transits, and decent efficiency and I think I came up with a great sounding design thanks to Dayton Audio. And whats really amazing is I manage to get the DC28F-8 to around 1400Hz while still playing loudly and cleanly. Stands up to my Proton D1200, It’s such a great tweeter.

  5. 19

    Great sounding, great looking speakers at an incredible price. If you wanna hear a great speaker that takes you back in time, these are it. Can’t wait to see what he comes out with next

  6. 22

    Great sounding speakers @ a very reasonable price. He doesn’t skimp on quality. Don’t let size fool you either. These speakers are definetly under rated in their specs. I would put his knowledge of building speakers and allowing his name to be represented with any speaker in that price range.

  7. 24

    Great speakers especially in this price range. I’ve been fortunate to see and hear/ use a few of Frankiegeees designs. He definitely focuses on quality.

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