The Daedalus is a floorstanding 3 way speaker based entirely on the Dayton line of Reference Series drivers including the Dayton RS225S-8 8" shielded aluminum woofer, Dayton RS125S-8 5" shielded aluminum midrange and Dayton RS28A-4 1" aluminum dome tweeter. The goal of this project was to determine how the Dayton RS drivers compared to the Seas L series drivers in a three way speaker design. The design is somewhat similar to my Alpheus design in that it uses similar crossover points and slopes and similar driver sizes so a fair comparison can be made. Considering the lower cost of the RS drivers, the Daedalus costs slightly less than the Alpheus project but they certainly don't sound that way. The Daedalus have to be the most balanced and detailed speakers that I've designed to date. At 84 dB they are slightly more efficient than Alpheus design and play almost as deep with an f3 just below 30 Hz. These speakers have become the new king of the hill and I'm going to have a tough time trying to top these. They are by far the best value of all the speaker projects on my site although they aren't cheap ($500-$600 a pair).

The Daedalus design is not related to or associated with Daedalus Audio or the designs at that link.


The Dayton RS28A-4 tweeter is designed to be an excellent match for the Dayton Reference Series woofers. The tweeters' unique black anodized 1-1/8" aluminum diaphragms and state-of-the-art motor systems not only match the look and features of the RS woofers, but also match the clean, detailed, and uncolored sound. A cast aluminum faceplate, protective mesh grill, tuned rear chamber, and several distortion-reducing paths in the motor system are just a few of the features that allow this tweeter to outperform many expensive audiophile high-frequency transducers.

Dayton RS125S-8 & Dayton RS225S-8 - The Dayton Reference Series sets a new standard of value in high-performance loudspeaker drivers. Utilizing a low-distortion motor system with two short-circuit paths and a rigid aluminum cone, the Reference Series can outperform drivers that cost several times the price. Their low-distortion characteristics and high excursion capabilities provide exceptional clarity, detail, and dynamics. Woofers feature a shielded motor system, black anodized cone, heavy-duty 6-hole cast frame, low-loss rubber surround, and solid aluminum phase plug. The Dayton RS125 has a power handling of 30W RMS/45W peak, an Fs of 72 Hz, an xmax of 2.8mm, and a sensitivity of 86.5dB@2.83V/1m. The Dayton RS225 has a power handling of 80W RMS/120W peak, an Fs of 27 Hz, an xmax of 7mm, and a sensitivity of 88.1dB@2.83V/1m.

Place mouse over picture to see cabinet with grills removed

Cabinet Design

For the Daedalus I went with a dual cabinet design primarily to make them easier to move by splitting the total weight into two separate cabinets. The top cabinet houses the tweeter and midrange and has a compartment for the tweeter/midrange filter in the back with a removeable back panel for access. The midrange enclosure is 9.3 liters which is a bit large but I'm using the same guidelines as the Alpheus design and a larger cabinet should only help the midrange sound since I will be filtering them above the frequency where the response begins to rolloff. I chose to use bi-amp terminals on the back of the midrange/tweeter enclosure. There is a single brace and I lined the cabinet with 1.5" foam below and to the sides of the RS125 and used 2.5" foam for the rest of the enclosure as well as 100% polyfill stuffing. The bottom cabinet houses the RS225 woofer along with its crossover connected to a single set of binding posts so the entire speaker can be tri-amped if desired. The volume of the woofer cabinet is roughly 50 liters with a port tuning around 29 Hz. There is a generous amount of bracing including 'O' braces and 'U' braces to reduce cabinet wall reflections. Most of the walls are lined with 2.5" convoluted foam except the wall opposite the port opening to prevent air flow restriction. The sides of the cabinet just behind the woofer are lined with 1.5" convoluted foam so the back of the woofer opening isn't blocked. The middle and top of the cabinet are very lightly stuffed with polyfill. A 3" precision flared port is used to vent the cabinet. The bottom cabinet weighs 50 pounds while the top cabinet is 25 pounds with the crossovers and drivers installed. All of the drivers are flush mounted to improve performance and increase clearance for the 1/2" grill frame in the case of the RS225. Neodymium magnet grill fasteners are used to hold the grills on and are hidden behind the vinyl covering on the front baffle. Parts Express black ash vinyl was used for all cabinet sides except the front baffle where the textured silver vinyl was used.

Crossover Design

Having just completed the Alpheus three way design, the crossover for the Daedalus was pretty straightforward although I used a few different tricks this time. The Daedalus uses a crossover frequency of around 220 Hz between the RS125 and RS225 with 2nd order, 12dB/octave acoustical slopes. The RS28 is crossed at 2kHz with 4th order, 24dB/octave slopes. Relative to the Alpheus I simplified the woofer crossover and only use a single 5mH steel core inductor (for low DCR) along with a 150uF capacitor and I used a 125uF bipolar electrolytic in parallel with a 25uF poly cap in order to save some money and space while still maintaining decent performance. The midrange filter uses a parallel notch filter to tame the resonance modes of the RS125 instead of the series notch filter that I used in the Alpheus design. This notch filter attenuates the resonances by 40 dB which is more than enough. The tweeter filter is just a simple 3rd order electrical filter with a notch filter. The notch filter is tuned to around 11kHz which flattens out the top end of the tweeter response and reduces the amount of rolloff above 12kHz. The only problem with the notch filter is that it lowers the impedance to around 4 ohms at the top end of the response but this is acceptable and shouldn't be too much of a strain on most amps partially because it is at such a high frequency where the typical power levels are lower. For the midrange filter I used a 60 uF metallized poly capacitor in parallel with a 20 uF poly capacitor to obtain the 80 uF value. I tried to stick with the Dayton theme by going with all Dayton poly caps and Dayton non-inductive resistors plus I like to use them anyway because they are a very good value. Most of the inductors are 20 gauge Jantzens except the 5mH midrange value which is an 18 gauge Jantzen and the 5mH woofer value which is a 16 gauge steel core inductor. When wiring the drivers to the crossover remember to wire the RS125 and RS28 out of phase to insure proper phase alignment between the drivers.

To the right is a picture of the assembled crossovers. The top picture is the midrange/tweeter crossover which is located in the compartment in the back of the top cabinet. The bottom picture is the woofer filter which is mounted to the inside of the woofer cabinet directly behind the woofer. If you place your mouse over the picture the back side of the crossover board is revealed as if the crossover has been flipped horizontally. I tried my best to keep the inductors from interfering with each other and I think I did a pretty decent job considering the number of inductors in the filter. The crossover boards are made from 1/2" MDF and the inductors are held down using nylon tie wraps. The crossover boards are mounted to the cabinets using a pair of screws using the predrilled crossover board screw holes shown in the pictures.

Place mouse over each crossover diagram to see the back side of the board

Performance - Page 2