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Celestion TF1225 with Eminence PSD2002 + SST1 horn Having tested out the TF1225 with the Pioneer PD-40 horn, it is time to design a 2-way for PA. Base on sound quality, my woofer of choice is the TF1225. If more power is required, I can always redesign it with a Dayton PA310 or the Peerless FSL 1225R02-08. The horn combo section is the Eminence PSD2002 with the SST1 horn. I opted for this horn because of it’s constant directivity properties. This will be an advantage when the speaker is used in a church or outdoors. The PSD2002 compression driver is noted for it’s robustness in pro use. I am quite confident it will tolerate being crossed at 1.6kHz.
Fig 1 is the Celestion TF1225 (Blue plot) with the Eminence PSD2002 + SST1 (Red plot). The Black plot is the summed response. Electronic crossover is a Linkwitz-Riley 24dB/oct set at 1.6kHz with CDEQ activated. Frequencies below 500Hz includes reflections in my room. Disregard the notch at 125Hz. That’s caused by a floor bounce.
The Violet plot in Fig 2 is the null response when I reversed the phase of the PSD2002. I am surprised by this null because no delay is used. The sharpness and depth of the null indicate the TF1225 and the PSD2002+SST1 combo are almost time-aligned. Fig 3 is the summed response of the TF1225 with the PSD2002/SST1 combo. After listening to it with various genres of music, I found this is the best tonal balance. Just 1dB more on the PSD2002 and the speaker will sound bright. I will use this response when I design the passive crossover. Sound Quality of Celestion TF1225 with PSD2002 + SST1I have no regrets choosing the Celestion TF1225 with the Eminence PSD2002/SST1 combo. The sound quality is fantastic. It’s even up to Hi-Fi level. With it’s enormous headroom, this speaker is ideal for Home Theater and tube lovers as well. For home use, I would replace the SST1 horn with perhaps a FaitalPro STH100 but I’ll leave that for another project. Most important is for pro use, I have a speaker that is superior to those run of the mill PA 2-ways in the market. My next step is to design the passive crossover. Unless otherwise stated, all measurements were made with the mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied. |
August 5, 2020Drivers Evaluation, PRO DRIVERS
Fig 1 – Blue plot=Celestion TF1225 Low Pass | Red plot=PSD2002+SST1 High Pass | Black plot=Summed
Fig 2 – Null response