Selenium HC23-25 with Peavey RX14

This HC23-25 is a budget 100°x40° exponential horn by Selenium. It is a 1″ throat, screw mount type with plastic threads. I’ve never found a compression driver (CD) that matches this horn until recently. The RAW frequency response below (Fig 1) is the HC23-25 with a Peavey RX14 screwed onto the rear. No crossovers are used in this measurement. However, a sine sweep with the bass removed was necessary to prevent damage to the CD.

Fig 1 – Selenium HC23-25 with Peavey RX14 RAW Frequency Response.

While the response is not ruler flat, it does offer some advantages. Mainly, her SPL is almost constant in her working bandwidth from 2kHz~10kHz. A response like this will make designing the crossover easier.

Fig 2 – Selenium HC23-25 with Peavey RX14 Toneburst Energy Storage

Fig 2 shows the stored energy (light blue slices) in this combo. Bear in mind that the z-axis is in cycles and not time.

Fig 3 – Selenium HC23-25 with Peavey RX14 Waterfall

The Waterfall plot (Fig 3) shows the stored energy in time. The artifacts are about 3kHz, 9kHz and 20kHz. None of them are detrimental to the sound because we are looking at them at a micoscopic level.

Fig 4 – Selenium HC23-25 with Peavey RX14 Spectrogram

The Spectrogram in Fig 4 shows a 2-D version of the above. In the operating bandwidth (2kHz~20kHz), the artifacts do not last more than 2msec. Basically, they are inaudible.

Fig 5 – Selenium HC23-25 with Peavey RX14 Harmonic Distortion

The Harmonic Distorion (Fig 5) is quite low. 2nd harmonic is at 0.141% while the 3rd is even lower at 0.096%. I can expect lower distorion figures when a crossover is installed.

Summary

I have yet to audition this horn but I must state I’m not impressed by her quality. The HC23-25 is very flimsy and poorly made. In fact, the two plastic fins broke in my hand when I tried to screw in my JBL2414H-C. So, the measurements were all made without them.

Another aspect that really annoys me is the plastic threads for her throat as opposed to a brass insert. While my Peavey RX14 is able to screw in with some tightness towards the end, my JBL 2414H-C simply wouldn’t even make past two turns. Forcing it would certainly bind the two.

In my next post, I’ll test out this combo with a woofer to see whether this Selenium HC23-25 is worth pursuing.

Unless otherwise stated, all measurements were made in Full Space (4 pi) with the mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied.