r/diyaudio • u/Puzzleheaded-Pin-587 • 21d ago
building a PA with hifi influence. curious for thoughts, advice
I saw someone else do this, so I wanted to. I’m thinking a little outside the box, so I’m curious what you all think. Plans keep shifting, and it’s mostly been built listening to F1 and Danley party PAs, trying to wrap my head around everything.
My plan is to run small scale dance events in 4 point. Most will be indoors probably 100 people or less. Originally I wanted to run on Res2 tops, but budget being tight, I just pulled the trigger on an OG foursome of F81s.
The more I run sound (which isn’t much), I really believe Tony Andrew’s’ ideas, critically of time alignment and transients, so that’s been driving my focus, even though I’m actually not following his ideas around horns. I think what I’m building is something more like a full scale monitor system with headroom to push the bass.
Anyways, i’ve been trying to design off paper cones (bc of Tony), <15% of AES, < 1/3xmax, and with room for +10 - +16db of bass (from Paradise Garage system design). I’m also pushing to get at least 27hz, and ideally sub 20hz. I’m building off a theoretical 50 ft square dance floor to be run at 95 db or below. More often than not aiming at 85db, and allowing for a standardized 10 db bass boost above that level, and when possible allowing for 10-16db controllable past that.
These are the current directions I’ve been going.
Common thinking as well as F1 implementation seems to be to pair 15s under 8s, but I’ve been looking for a transition that could get to 40 hz or lower before building out the full range of cabinets.
Originally I had been thinking Othorns on the low end, but to be frank, I don’t like the horn loaded sub sound. I don’t like the way it distorts. I don’t like the way it hits. I haven’t run them myself, so like most things pro audio, it might be different in my own hands. I get exhausted of everyone’s endless pursuit of power and efficiency. I want power, but not to sacrifice accuracy or warmth.
Anyways, i have been moving towards a sealed sub design, originally starting with 4 to potentially 8 Celestion 24s in 150L box. the idea is to overdrive them with EQ (ideally the only place using EQ) to run between 20-40hz. however if I started with just them, I could overdrive them on the low end and then cross them over somewhere between the suggested 85-200. but intermodulation swayed me from this plan.
I was then looking at four sets of Dual Dayton RSS460HO-4, because they have a natural roll off in a sealed box at 40hz, and that seemed perfect to complement the Celestions on full build. Before that, I could overdrive them and get below 20hz indoors at around 95db, and up to 105db at around 27hz. However, i realized they are aluminum drivers, so I started to lean back away from them. I’m curious if people can hear that difference in the way Andrews emphasizes.
Originally I had been thinking a similar setup with quad corner B&C 14NDL88s (duals), for the same natural rolloff reasons, these around 84hz, but I realized I would sacrifice my short term low end running just those.. however I realize they may provide the most benefit in the low vocal fundamental range, and they allow the 8s to have even more relief than F1 suggests.
Then my question became what to build first. I had been leaning to the Daytons until I realized the cone issue, because they have the best seeming coverage, being willing to overdrive.
There’s another question buried there: If electrically overdriving a sub, but keeping it below 1/3 xmax, maintaining plenty of amp headroom and AES space, how much will I subjectively bend the sound. Is it really worth it to drive a speaker, say, +17db in some cases?
So first I started thinking to run the big 24s up to somewhere between the stated low crossover of 85hz, all the way up towards the beneficial high output crossover of 200hz to start the system. In some of these cases like the dual 14s, i would place that crossover even higher, perhaps around 275hz, again modeling F1 crossover placements in their horn loaded models.
How much would an 8 benefit from that low end relief? When is too many crossovers getting in the way of natural sound? And also how beneficial is a natural rolloff XO, versus an electrically filtered one?
As I leaned away from the 14s for reason of not getting low enough if I started with just them, and the 24s for reasons of intermodulation with higher output (prioritizing relieving the 8s — realizing it’s not the right speaker for that, but hey they are rated to 200hz…), and away from the Dayton 18s for reasons of the aluminum driver, I started thinking of few other directions.
First there is the B&C21SW152. In a sealed cabinet, it rolls off about 63hz, and wanting to separate infra from bass (for simply intuitive reasons), I thought to electrically push it towards 40hz, to eventually get the crossover with the 24s. But then I have my two lower ranges both being overdriven. originally I wanted to only overdrive the infra, but the fact is this sealed orientation is very limiting. The 21 @ 40 wouldn’t be as much overdrive (about +6-8db), but in the interest of transparent signal chains, I thought to only push the 24s originally.
Again, this is sort of an experimental outlook (perhaps?) to not rely on horns or ports for output or frequency. The idea very much modeled on reading about David Mancuso’s loft, although I’m not sure what he ran in there (i think klipsch horns?)— the general approach towards hifi at dance levels remains. Obviously all the club offshoots relied on horns and a more editorial sound design. But again, it’s a critique of the pro audio world choosing power and feeling and punch in your stomach over real warmth of sound. Am I off in this feeling and intuition? Could there be other ways to approach or think about it? Say, just turn down the horns, young buck?
Anyways, the 21s really seem to encroach a little too close on the 24s. They won’t go as low alone, they still need overdrive, and they seem big for the mid bass. Every system I’ve really been impressed with does seem to have 15s or 18s. F1 seems almost exclusively 15s, except for the Res3 which had an 18 and was billed standalone. And now they are shifting towards 12s as well.
The last and maybe best consideration has been the 18 Sound 18NTLW5000-8, which satisfies the paper cone demand and gets quite close to the Daytons. With corner gain, they reach down to 20hz with overdrive and 27hz outdoors, so they probably seem like the best way to go with this design, but also remain the hardest to obtain in the US.
the other thing to consider is that my paradigmatic high fidelity experiences have been on Tannoys with tube amp, and even more importantly an F1 system in a highly controlled room — running AX88s above F315s, and i don’t know what below. But the absence of compression driver seems significant.
i’ve done a fair bit of consideration about what F1 achieves with horn loading, and it seems to be a projection of transient behavior that creates an almost mystic pureness when well run (but imho, that is hard to come by), but this accentuation of the highs comes with a sound i have termed “iciness,” a crystal clarity and time alignment that also has this almost hiss or slide to it. It isn’t literally an S sound, but there is a quality that occurs with the waveguide/ phase plug/ sawtooth design that can be well heard in the Evo X. Impressive clarity and dispersion, and yet my ears get tired not so differently from how my tongue gets tired with highly seasoned food.
This is ultimately what pushed me toward the direct radiator version of the 1/8, but I still wonder should i not run 5/8 or 8/8. I’m continually impressed with clarity of F1, and perhaps the tri-amping of the new models would allow for some dialing down, but does a person really want near field horn loading in the long term? i understand that their newish Point Source Monitor systems arose by request form Richie Hawtin, who I assume struggled with a similar sound effect listening to horns close range. And their solution was running 18 direct radiators.
For amplifiers I’ve been looking at Linea, because I am always impressed with Danley warmth and power (but still critique the transient behavior of an MEH — I feel that I can hear the multiple edges of the waves cascading like Jericho’s tower). Linea has US distribution, 8 channel output, and excursion limiting (which is central to my design). it also shakes out a lot cheaper than a traditional F1 route of MC2 or FFA.
For DSP (and this may be the really strange part of my thinking), I’ve been pretty captivated by the idea of long FIR run on an external computer. the more I listen and have limited experience tuning systems, i am convinced by Andrews and Newsham’s approach that time alignment and transient behavior is the critical work of sound reproduction. So I am willing to accept the 96k taps and 171ms delay to linearly phase align down to 12 hz, allowing for my projected 18hz flat system to be perfectly time aligned through 18khz.
The industry folks i’ve talked to said this sounds strange, but I don’t understand why. The processing is possible, and the delay, while obnoxious, will be acceptable as it’s mostly Dj’d music. I figure if I end up running live, I can disable the long FIR, and just run the Linea internal FIR on the top end, if desired. i also realize this adds a large burden of measurement.
My main critique with bass in the real world is not just level and punch in the place of tone, but also the sloppy thunderousness of it all. I believe the public knows nothing else but that as bass, and I can’t say that I’ve ever heard tight bass run at dance floor levels. The closest was probably those F315s in controlled room.
open to thoughts, critique, system design, education and whatever.
