peniku8

I agree on the 3 seconds part. Amps either drop off from burst power to sustained power within a fraction of a second or they're burst power=sustained power type of amps. Looking at my Sanway test reveals that nothing much changes after the cap banks are drained (after just shy of a second). After 2 seconds it ended up on its sustained power level, which would happen even faster when driving two channels. I think I'll go with 3 seconds at 1k, 100, 60, 30, 15 and 8Hz. It cuts down on my testing time, is less hard on the amps and my breakers are unlikely to trip like this. Looking back at my initial test, the 90 seconds test was pretty stupid. 90 seconds 100% duty cycle into 2R of a fan modded amp... I will fool around with REW and stepped sine wave tests as well, maybe that reveals some interesting results (It can step level now and not just frequency)

Tbh I'd personally buy a large enough 3D printer. I have all kinds of equipment, which includes a CNC router, but even then, making horns is something I'd find cumbersome to do. Doing it on the CNC would require doing it in something like 1" slices. Doing it by hand with something like a large Dremel... inaccurate and really tideous work...

It was 1khz, which meant maximum heat development in the amp, which was the cause for its failure. It sustained over 7khz (single channel) into 2R for 260 milliseconds at 1khz. That's 260 cycles. Wouldn't that means it's able to do 2.6 cycles at 10Hz at 7khz or does it behave differently? I was planning on measuring at different frequencies as well, but I have so many things on my plate at the moment, I can't tell when that'll happen. I was also pretty pissed when the amp went up in smoke, which is why I stopped testing. But I think it should be fine if I limit it to 10 second tests instead of 'seeing what will happen' (I left the amps running at max for 2 minutes). The amp threw my 16A 230V breaker after 16 seconds anyways, I should've left it at that instead of plugging it into a 32A circuit.

My Sanway clone amp handled 2R (one channel) sustained without issues. I let it pump out 4KW (again, one channel; sine wave) into my loadbank for over a minute, but kinda forgot it was fan modded, so it overheated and blew up on me. I'd be pretty confident with the newer and sturdier version (mainly power supply changes with an additional fan next to the parts which blew up) when it's not fan modded. It muted the output pretty quickly into 1R (matter of milliseconds; SC protection kicked in), so it might not like it if the impedance of the actual cab dips below 2R.

I'd say you have a pretty good overview already. I have 4 21ds115, but if you want some 1-2db more headroom, go for the Eminence. Your call if you wanna spend the extra on that. For me (in Germany), the Eminence is twice the price than the 21ds115. It's actually almost the same price than the 21IPAL here. In the states it's more like 500 vs 700$ between LaVoce and Eminence I think. I'd personally go for the latter there.

You mentioned running limiters. Do the CVR amps have true power limiters? I'm looking for an affordable amp with a proper limiter and plenty of power. I own two Sanway amps (an FP13k and a D10Q, which is a dsp amp), but both have pretty useless peak limiters...

That looks dope! Were you running them off the CVRs?

Nah, that wouldn't impact the direct sound at a close range like that. It sounded like there was an 8khz high shelf on the bottom 2-3array elements which boosted that region by some 6db, in addition to being way too loud (it was an easy 10db louder there than everything past some 20ft from the stage. I didn't dare to go there again..!

Yup, had everything cancelled for the last 15+ months, bar a single wedding. First show in a long while was 2 weeks ago. Audience of 200 (seated) in a location for 2000... was an interesting show. They had l.acoustics there with 10-12 Kiva line array elements per side. They were all running the same settings, which sounded to me like a distance compensation for ~30m (100ft) or longer, which meant the first few tables were being decapitated by extremely loud top-end... Guess we're all a bit rusty after such a long break or they just didn't care

https://www.avsforum.com/threads/diy-mid-hi-bms-coax-2x-12-b-c.3006048/ Almost the same setup, I think @dsl1 was very happy with it

The magic of PFC... love it

Thanks for the paper, I've been looking for some more info the topic! If you had access to a flow sim software, you could probably get some decent info out of that, even if it works with (non compressible) liquids.

Bennett from B&C suggested setting the true long term power limits around 1/10th of the program power, which would be 500W for an ipal for example, or 360W for the 4,5" 21DS115. I have no clue how good the cooling is on the Pyles, but power handling also depends on cabinet type, as you get less excursion (so less cooling) in sealed cabs for example, but I'm pretty sure you're not using sealed cabs for PA. You could try running the sub at a certain power limit for a while and measure the TS parameter shift. Or measure it acoustically and see where power compression sets in, maybe that is a good indicator as well.

What I found interesting is that, as SME already described, I think the reference point for 'loud' music listening at home (mid and near field) is around 80dbA, which is where the 'excitement' starts and I feel engaged with the music as my main element of sensual stimulation. In a live setting in a large hall or outdoors, I found that this 'excitement' starts at pretty much exactly 100dbA. I've mixed a show at 97dbA and it was just lacking excitement. When I boosted the overall volume to around 100dbA, it was there, 103db and it was too loud. My show still was a few db less loud than the main act's, which I found too loud (rock with bagpipes, which can be pretty nasty up high). At home I'd die at 100dbA, that's just nuts, even for just a short moment. But what I've also found was that the lower the distortion of the system, the higher the point where "loud" becomes "too loud". I've finished a new system for my studio last week, which shouldn't exceed 0.2%THD@100db/1m 100Hz-20k and had a listening session with my dad. I turned it up a bit, but it didn't seem too excessive to me, until I tried to talk to my dad and noticed that he could barely converse, even while screaming at each other. It was a bit shocking and since I've installed the speakers in the studio I need to constantly remind myself to not turn it up too much, because now distortion is no longer an indication of loudness. Interestingly, the woofer and mid will show power compression even before they exceed 0.1% THD anywhere in the spectrum the operate in, which is very astonishing. Now I'll just need to build a sub for the system, but I haven't even tested it out for its bass capabilities. The four 8" drivers should make some decent noise near field, but are of course limited in the lower regions since the designs are sealed (avoiding port resonances and noise). Anyways, I'm pretty sure that system won't have a problem hitting 130db throughout most of the spectrum. My single near field SKHorn could already exceed 130db, I have no doubt that your system barely breaks a sweat at THX reference, unless you're going after the single digits.

Weapons of mass destruction..!

I did use complex Le and my vent area are more than yours, even if you double the numbers to combine the two ports. I will PM you my HR inputs, but I usually manipulate the inputs there in a way to get results closer to real-world expectations. My thoughts on the design after a while: -I've used them at a few weddings and the performance was great. I have a sub-octaver on the cajon, which adds a nice 40-45Hz low end to the kick drum, which would be hardly achievable with run off the mill 12" PA designs tuned to 55Hz and what not. -They can take a lot of power and I've never noticed port noise, but theres some early compression creeping in, which is just natural for a design this size -The expansion of the port towards the outside is too much I think. It might cause separation (and turbulence) there, which could be remedied by an extra element to guide the air, but I'd maybe just make the expansion less logarithmic... I'm learning a bit from a youtube channel called Kyle Engineers, which is an ex-mercedes F1 engineer -A bigger port gives you more performance of course, but the goal here was space-efficiency obviously, and it needed to be a one man setup which won't break my back. The design is lacking a bit of punch compared to my 21ds115 cabs, but I guess that's only natural since those are front loaded and.. well 21"

I finished a 6Ch amp build made from two Hypex FA123 yesterday. It's a lab amp for speaker testing, so it has all connections on the front. It's not the prettiest and already has a bunch of scratches, but hey, at least it's got cable management..!

Wow, that's a clean looking build, nice!

Designing a crossover requires measuring the drivers' frequency and impedance response, which means you'll have to build and fully assemble the speaker to do so. If that hasn't been done, the crossover is more or less a random assembly of components and it delivering optimal results is about as likely as winning the lottery. Like SME already mentioned, the question here is if you want to: -design and build a speaker outperforming a store-bought solution at the same price or for even less money (typical DIY approach) -design and build a speaker just for fun, with no particular focus on the quality of the final product -design and build a very specific and unique speaker not available on the market If your goal is the first on the list you'd be best off with building an existing design that fits your bill. If it's the last, get ready for dozens of hours of reading, because there is lots of knowledge out there, plus spending ~300$ on measurement equipment for FR and impedance sweeps. If it's the 2nd, stop worrying, build something and ignore our nit-picking

The MDF I have is 800kg/m³ and my ply is 650kg/m³, which makes the MDF 23% heavier. My dad has some old Klipsch speakers made from plywood which feels like half the weight of the plywood I'm using for my subs, there are huge differences. I worked a lot with MDF lately (for studio monitors) and I'm not a fan of it. Won't hold screws well is my main issue here, since I don't care about the dust (my 7KW dust collector leaves nothing on the cnc). Will probably switch to carb2 CDF for the baffles at least, even thou it's literally 6x the cost. Those old Klipsch speakers are a mess imo. Light ply with no bracing, no gasket tape on the hatch and the tweeter and mid horns are back-mounted on the 1" baffle...

A nice video on the topic by Bennett Prescott, B&C US sales manager:

The driver can handle around 400-500W true long term average power, which is about 55V at Zmin. You'll have to find out the minimum impedance of the driver in the cab to be sure, but pure voltage limitation isn't ideal anyways.

You're gonna have a really bad time if your crossovers are not specific to the components and the cab they're built into, unless you're planning to throw a dsp at it

Yea, but 700AUD is 440€ and the 21DS115 can be had for 400 here atm, if you take 4. Last time I ordered I paid 380 per driver (bought 2). Am B&C OEM now thou, so I can order directly. Can't tell those prices for obvious reasons

Holy crap, that Dayton is more expensive there than a 21DS115 is here Should be reasonably good in the Skram thou, Bl is high enough for it to make some rumble in the cab.