| A custom semi-PA speaker system with a nod toward vintage JBL. It was a fast-tracked design & build for a local pop-up "kissa" music lounge made possible by a group of mostly volunteer collaborators. The need was for a system in a ~5000cf cafe: Good to 40Hz, linear enough for high fidelity to 15kHz, sound good at 90~95 dB SPL (1m) as well as up to 110 dB for the "nightclub" sessions. The speaker project was green-lighted at the end of March for opening night on May 23. Installation would occur in the 4 days before. A very short timeline. So with tariff wars, no imports, only Canadian sources of components, primarily Solen, and whatever I already hand in hand. I studied catalogs & databases for a few days in April, scoured my own shelves, and came up with a plan with mostly SB Audience components from Solen: B-52 PHRN-1014 1" Horns -- 90x40 directivity, low 600 Hz cutoff, long discontinued but I had a pair on my shelves. They were the most suitable horns for this project. I also had Eminence N151M-8 1" Ring compression drivers and B&C DE250-8 1" Polyimide Horn Driver. But experiments with these CDs on the 14x10 horn did not impress me, so took a chance on the SB Audience ROSSO-44CDN-PK compression driver. This proved to a lucky exceptional match with the 10x14 horn. No way I was going passive with this. A miniDSP 2x4 HD was in hand. It would accelerate XO/EQ development, & allow finetuning the system for the venue. SB Audience NERO-12MWN700D is a recently released 12" high efficiency pro “mid-woofer” with neodymium magnet. FR looked good to past 1kHz. Its 54 Hz Fs and modest 7.3mm Xmax looked like serious limitations, but the 18mm peak-to-peak Xdamage was somewhat assuring. A 30 Hz steep high pass crossover filter, 48 or 24 dB/oct, could be applied for protection; fingers crossed that wouldn’t impact sound quality. WinISD calculations showed a 2 cf box tuned to 47 Hz for flat response to around 50 Hz. That was better than the QB3 alignment in WinISD, with Vb of 1.55 and port tuned to 54 Hz. DSP could extend this down a bit. The maximum SPL predicted by WinISD at 50 Hz with the 150W available was 115 dB, which seemed plenty though optimistic. After development on my PC, I built the enclosures, tested & finetuned the system with horns mounted externally on shock absorbers (which definitely helps retain clarity at high SPL). About 1.5 sheets of 4x8' 3/4" G1S Chinese-made BB plywood was used. Cheaper than the Russian 5x5'. The XO was LR4 at 1kHz after PEQ applied to smooth both driver responses. There was about a 6-7 dB boost to flatten F3 response to ~38Hz, and some other relatively minor tweaks. Further improvements might have been possible, but time was very tight, so after I determined the subjective performance to be pretty darn good, several other Kissa team members auditioned and deemed them worthy. Then the drivers were removed & boxes handed off to another group member who who applied a "micro-cement" finish with gobs of blue dye. The box came back to me 10 days later, at which point it was rush rush to get them installed and running at the cafe. The REW FR curves for left and right speakers are the only ones I managed to measure on the day before the opening. With others working on cabinet installations, counter renovations, new curtains, and new ceiling damping panels, plus the constant noise of the refrigeration units in the cafe, it was very difficult to measure anything. The mic position was ~2m, with 10 deg of vertical/horizontal axis. The only PEQ change made after these sweeps was a 4 dB Q=3 boost at 14kHz to counter the falling response. That was perceived as an improvement by everyone who heard the difference. The end result was successful: Many participants who attended the "curated musical exploration" sessions over two weekends praised the sound, calling it the best they'd heard. Some whose hearing was damaged said it was the first time in years that they'd heard music so clearly. This probably speaks to the relatively low sound quality of audio systems most people are exposed to routinely. Still, I have to say the speaker sound much better than I'd expected in the space. Bass, especially, is quite powerful & extended, to a bit below 40Hz. Dynamics are excellent, and they apparently did fine in the 4 nightclub sessions as well. For now, the speakers and dedicated XO/amps remain at the cafe, with the "kissa" project taking a hiatus. The owner is delighted with the extra traffic & business to the cafe & his restaurant next door, and with the option to use the system routinely. |
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Good question, @JoshK
The horns were bought from Parts Express years ago: https://www.parts-express.com/B-52-PHRN-1014-10-x-14-Plastic-Horn-Waveguide-299-2303?quantity=1 This comment from 7 years ago might have have sparked my purchase:
I scoured retail listings and found nothing this size with a 1" throat. Not sure that it's directivity actually extends to 600 Hz, as specs claim, but the size seems an important aspect of its performance.
The only really good options I found are the
ATH Tritonia Waveguides DIY kits by Marcel Batík, specifically the M or F. The F is 422 x 364 mm (16.6 x 14.3"), vertical coverage 100°, fairly constant from 800 Hz to 16 kHz. Pricey by the time you get it 3D printed & finished, and maybe overkill, but I bet it sounds better than the PHRN-1014.
The smaller M would be cheaper:
The horns were bought from Parts Express years ago: https://www.parts-express.com/B-52-PHRN-1014-10-x-14-Plastic-Horn-Waveguide-299-2303?quantity=1 This comment from 7 years ago might have have sparked my purchase:
I scoured retail listings and found nothing this size with a 1" throat. Not sure that it's directivity actually extends to 600 Hz, as specs claim, but the size seems an important aspect of its performance.
The only really good options I found are the
ATH Tritonia Waveguides DIY kits by Marcel Batík, specifically the M or F. The F is 422 x 364 mm (16.6 x 14.3"), vertical coverage 100°, fairly constant from 800 Hz to 16 kHz. Pricey by the time you get it 3D printed & finished, and maybe overkill, but I bet it sounds better than the PHRN-1014.
The smaller M would be cheaper:
This looks like a nice fit for the Nero 12MWN700D woofer.
It turns out that I actually bought 4 of these horns back then. Found a forgotten 2nd pair stashed in big storage bin. 😅
Nearfield. As a result, the 2nd graph won't be that useful. It was running probably under 90 dB/1m SPL. I tried LR4 XO 800-1400 Hz with PEQ but felt the system sounded best at 1-1.2 kHz. With the steep 24 dB/oct slope, the CD didn't exhibit much higher distortion even at 800 Hz XO but put it up higher for some margin of safety during the nightclub sessions.
FWIW, the amps driving this system is a pair of @Erica.C 2x150W class D amps in a somewhat kludgy aluminum + wood cover case. It weighs all of maybe 8 lbs and is about the size of 2 largish dictionaries.
The alternatives were a Van Alstyne Double 400 Amp that weighs 50 lbs, and a Bryston 3B. The 2 together weigh >70 lbs & wouldn't fit in the available space.
The 2x150W amps came through with flying colors during the two weekends when the system was run continuously for 8~12 hrs daily, at high volume during the 2-3 hr night sessions, likely 110 dB/1m SPL. No hiccups whatsoever. 😎
The residual noise of these amps is such that when connected directly to the 110 dB/w horn/CD, the hiss/hum is plainly audible from over a meter away in a quiet room. But with the -10dB L-pad I used plus the high background noise of the cafe, this is a non-issue.
The alternatives were a Van Alstyne Double 400 Amp that weighs 50 lbs, and a Bryston 3B. The 2 together weigh >70 lbs & wouldn't fit in the available space.
The 2x150W amps came through with flying colors during the two weekends when the system was run continuously for 8~12 hrs daily, at high volume during the 2-3 hr night sessions, likely 110 dB/1m SPL. No hiccups whatsoever. 😎
The residual noise of these amps is such that when connected directly to the 110 dB/w horn/CD, the hiss/hum is plainly audible from over a meter away in a quiet room. But with the -10dB L-pad I used plus the high background noise of the cafe, this is a non-issue.
@mordikai
The nero-12mwn700 is an excellent woofer, ime. It lacks the deep bass below 40Hz, but its weight & clarity 40~200Hz, a band I increasingly believe critical, is excellent. Great dynamics & punch. Run in a 3-way in <2cf box with XO around 450~600Hz. Subs to supplement below 50Hz.
I plan an OB 3-way active build with it 60~800Hz, then XO to big ESS Heil. SB audience 15 or 18 at bottom. Probably have to add some kind of waveguide on both sides of the Heil to get it down low clean. Not sure how to make this look good yet, with the Heil's blocky depth.
A tower version of the Blue Wonder (my impromptu tag for the Kissa speakers) 1.5cf with smaller horn or WG >1" tweeter would be a fun, inexpensive party speaker that would do fine as a HiFi speaker. But I need to learn VituixCAD to pull off passive XO between mid/tweeter to reduce complexity of external wiring with all-active.
The nero-12mwn700 is an excellent woofer, ime. It lacks the deep bass below 40Hz, but its weight & clarity 40~200Hz, a band I increasingly believe critical, is excellent. Great dynamics & punch. Run in a 3-way in <2cf box with XO around 450~600Hz. Subs to supplement below 50Hz.
I plan an OB 3-way active build with it 60~800Hz, then XO to big ESS Heil. SB audience 15 or 18 at bottom. Probably have to add some kind of waveguide on both sides of the Heil to get it down low clean. Not sure how to make this look good yet, with the Heil's blocky depth.
A tower version of the Blue Wonder (my impromptu tag for the Kissa speakers) 1.5cf with smaller horn or WG >1" tweeter would be a fun, inexpensive party speaker that would do fine as a HiFi speaker. But I need to learn VituixCAD to pull off passive XO between mid/tweeter to reduce complexity of external wiring with all-active.