Jordan JX92S DIY Tower Speakers
Introduction - Jordan JX92S Tower Speaker Project
For this do-it-yourself (DIY) speaker project the Jordan JX92S fullrange driver is used to make a tower loudspeaker. The enclosure in a large (1.3 ft3) vented speaker box. This speaker system is well suited for medium to large sized room with medium powered amplification (more than 10W). The JX92S driver has good power handling (50W RMS) and a large Xmax of only 9 mm, so it can develop moderate SPL. The Jordan JX92S is a very well regarded fullrange driver which is known for it's smooth frequency response and it's ability to deliver much more bass than any similar sized fullrange driver.
Enclosure Design - Jordan JX92S Vented Loudspeaker
The goal was to get a good amount of low end response from this tower loudspeaker. Figure 1 shows the calculated frequency response for the JX92S in a 1.3 ft3 for a bass reflex cabinet (no damping material) and tuned to ~ 35 Hz. The frequency response was calculated using WinISD. The calculated -3dB point is about 30 Hz.
Figure 1: Calculated Frequency Response - Jordan JX92S Tower Speaker
See the Jordan JX92S fullrange driver page for the measured and factory Thiele-Small Parameters. As can be seen in the model of the frequency response, the T/S differences do not make much of difference in the frequency response.
The enclosure design for this loudspeaker project is shown below in Figure 2. See the construction photographs and notes for more details.
Figure 2: Enclosure Plan - Jordan JX92S Tower Speaker
Enclosure Construction - Jordan JX92S Loudspeaker
The enclosures were made using 3/4" Baltic Birch plywood except for the front baffle which consists of two pieces of 1/2" plywood laminated together. The inner piece of the front baffle fits tightly into the cabinet opening. The outer piece of the baffle was cut larger than the outside dimension of the cabinet and flush trimmed to size once the baffle was glued to the remainder of the cabinet.
The port is removable allowing for port adjustments later should they be required. The port was made removable by cutting a hole in the inside piece of the 1/2" plywood which was the outside diameter of the PVC port. Once the two baffle pieces were glued together, the outside baffle hole was cut with a flush trim bit riding the inside of the port.
Photograph 1: Jordan JX92S Enclosure Construction
Photograph 2: Jordan JX92S Speaker Box Construction
The final touches were a figured Maple veneer on the walnut all of which was finished in a gloss tung oil. Photographs 3 and 4 show the finished speakers. I also made some outriggers for spikes. They will give an otherwise tippy speaker some stability.
Photograph 3: Finished Jordan JX92S Tower Speakers
Photograph 4: Finished Jordan JX92S Tower Loudspeakers
Project Costs - Jordan JX92S Loudspeaker
Baltic Birch Plywood
Veneer (Maple and Walnut)
Stain, Glue, Caulking
Group buy, typical price $180/driver.
Estimate - Left over from previous project
Roll of Whisperwalk Carpet Underlay
Total cost ~$430US
Baffle Step Correction Circuit
You can use the baffle step correction / compensation (BSC) calculator to determine a BSC for your baffle width. The amount of attenuation will be room and amplifier dependent as well as personal taste. Typically about 3 to 6 dB of attenuation is a good. You can use the component values shown in Figure 3 and tune the BSC to suit your room and amplifier.
Figure 2: Baffle Step Compensation Circuit for Jordan JX92S and 8.5" Wide Baffle
For those interested in a Zobel circuit, you can use the Zobel / Impedance Equalization Circuit calculator to size one up. For the JX92S, the voice coil inductance (Le) was measured at 0.16 and 0.17 mH.
Conclusion - Jordan JX92S Tower Speakers
I took the speaker to a local audio event and the Jordan's were the hit of the party. Everyone was amazed by what the JX92S driver can do in these cabinets. My ears thought they blew away a pair of Heathkit / Altec Valencia style speakers that were in the same room.
Photograph 5: Jordan JX92S Tower Loudspeakers at Local Audio Event
They seem to be a bit on the power hungry side, but sounded amazing with a pair of McIntosh MC-30 monoblocks. We even ran them with a big JBL 15" subwoofer and the sound was rich and full. I guess the big tipoff on these speakers was that there were many speakers to listen too, and these stayed in the system for a long time and people kept coming back to them.
For additional information, photographs and discussion about this project see the Forum thread: Jordan JX92S Tower Speaker Build.