Dayton Audio Tower Speakers Part 2

Part 2,

Spent a few days reviewing my old notes and the changes I had made.   Below is the schematic drawing of the crossover.

Dayton Audio MTMWW final Crossover schematic

My design goals were to first keep the crossover design simple, thus keeping costs down by not having excessive components.  The crossover between the woofers and midrange is at 300 hz using a 1st order crossover for a gentle cutover between the midranges, which are basically a woofer to begin with and the actual woofers.  As for the tweeters, in my earlier designs I had used a 2nd order butterworth  crossover at 2000hz, but found that the tweeter had issues running that low and sounded harsh at times in the vocals.  I elected to raise it to 3000hz and use a Linkwitz-Riley 2nd order crossover.  I found the higher crossover point for the tweeter to be much improved, at least to my ears.  The mids handled the higher frequency just fine.  Overall impedance is 4 ohms.

Here is a picture of the main crossover.  This is mounted on the bottom of each speaker on a separate board that I can remove and work on the bench or change out completely.  Screw terminals make it easy to reconnect the drivers and to the terminals on the back of the speaker cabinet.

crossover pic

The Baffle Step compensation inductor and resistor I mounted externally so I could change out the 4.7ohm resistor during trial listening tests.

Note: The 130uF capacitor that I call out, most likely will need to be made from two or more different caps hooked up in parallel.  I had a 60uf, and 50uf cap left over from a previous crossover version, so I just added a 20uf to get my 130uf.

In Post 3 I will show the construction and finished speaker system.

Dayton Audio Tower Speakers Part 1

Back in the summer of 2011, I decided to try my first attempt of building my own speakers.  For years, I wanted to build a speaker system that was similar to various Polk and Monitor Audio speakers that I’ve seen and heard over the years.  I really like the RTA and SDA designs by Polk, so a lot of my choices were influenced by those systems.

What I decided to build was based on a MTMWW setup using two 5-1/4″ midrange,  one 1″ soft dome, and two 8″ woofers.  So after much research on cabinet design and speaker parameters, and cross over research I decided on using Dayton Audio speakers from Parts-Express.   I felt they were an economical solution with good parameters for a sealed box enclosure.

The speakers I chose were the following
Dayton Audio RS28F-4 1-1/8″ Silk Dome Tweeter
Dayton Audio DC130BS-8 5-1/4″ Classic Shielded Woofer
Dayton Audio ST210-8 8″ Series II Woofer

With that in mind, I had to design a cabinet.  I used Jeff Bagby’s Woofer Box and Circuit Designer to determine the woofer portion of the cabinet.  I figured that will get me the lower core box volume need for a sealed and enclosure.

My second part was to use Jeff Bagby’s Baffle Diffraction and Boundary Simulator 1.20  to figure out the best location for the tweeter and midrange on the front .  I used this information to also determine the Baffle cabinet width.

Playing around with various cabinet dimensions and speaker placements, I came up with this over all cabinet layout.  These are in a mirror layout.

Speaker cabinet dimensions

Tomorrow I’ll followup with further details on Crossover design.