JBL 580's - first comments and questions.

speakerman39

speakerman39

Audioholic Overlord
The order of the electrical crossover slope is simply the number of branches in the circuit. A first order has one positive branch (a coil for the woof, a cap for the tweet), a second order adds a branch to ground (coil for the tweet, cap for the woof), and so on. But the performance characteristics of a speaker depend on the order of the acoustic slopes--the rate at which the woofer actually rolls off at the top end, and the tweeter at the bottom. That's what the ear hears, and what affects its lobing pattern and phase characteristics. That will depend not only on the electrical circuit--the roll-off that arrives at the speaker's input terminals (also known as the transfer function)l--but on the inherent response of the woofer (and on the shape of its impedance curve). If the woofer has a sharply rising response above the intended crossover point, you could end up with less than a 4th order slope. If the driver is already starting to roll off at the crossover point, you could end up with a steeper than 4th order slope. In general, but not always, you end up with a steeper slope than the order of the electrical circuit. So it's not unusual for a speaker with a 4th order acoustic Linkwitz-Riley crossover to have a 3rd order electrical circuit, or frequently a second order. It's quite unusual for the electrical and acoustic slopes to be equal. At the extreme, if a woofer and a tweeter had very smooth 4th order roll-offs on their own, you wouldn't need any crossover at all (ignoring baffle step compensation), and the electrical "circuit" would be of zero order.
Thanks Dennis as this explains a lot. Honestly, I had read this several times, but I now have a better understanding thanks to you. X-over design is fascinating, but can also get very complex rather quickly. Are there any books of reference that you recommend that I could get my hands on regarding X-over/loudspeaker design? Many years ago I looked at Vance Dickanson's book, but it was way over my head. Perhaps, a more watered down version of some sorts would suffice? Thanks, once again Dennis!


Cheers,

Phil
 
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KEW

KEW

Audioholic Overlord
Are these sold out?
I was thinking about getting one if the price was good, and they show sold out on the main site, but I wasn't sure if there was a different place I need to go for a flash sale item.
 
lovinthehd

lovinthehd

Audioholic Jedi
Are these sold out?
I was thinking about getting one if the price was good, and they show sold out on the main site, but I wasn't sure if there was a different place I need to go for a flash sale item.
Clicking on that just now here on the west coast, says the sale starts in 25 minutes at 9am.....
 
lovinthehd

lovinthehd

Audioholic Jedi
FWIW clicking on the ad since 9am still brings nothing up, just that the sale is supposed to have started at 9am....maybe that's an indication they're already out of stock?
 
slipperybidness

slipperybidness

Audioholic Warlord
My Audiobahn car amps (chrome finish) also came with white gloves :cool:
 
slipperybidness

slipperybidness

Audioholic Warlord
They're not designed for fingerprints, but they're 100% cotton. More for keeping your hands warm than anything. I wore them under nitrile gloves and they kept my hands warm and dry. I used bring them home from work with me and toss them in the laundry with the whites. Some are a little stained (blood and dirt from the boxes the meat came in), but they're all clean. I've had to empty that drawer a few times now!

*Edit: I have this weird aversion to touching cardboard, paper bags and boxes. Especially if my hands are dryer than normal. I break out in goosebumps and the whole sensation is just very... unpleasant for me. It feels like he cardboard is sucking all of the moisture out of my hands where they touch. If I think about it hard enough I break out in goosebumps! Closest I can come to describing it is, it's like nails on a chalkboard for some people, only I have unpleasant tactile sensations and goosebumps that go along with it. *shudder*

All of our meat came in cardboard boxes so I wore those gloves pretty much all day at work.
LOL!

Yeah, every now and then if I touch a paper bag a certain way, I kind of get that odd feeling too. Didn't know that was "a thing".

But, ONLY paper bags for me, not cardboard or anything else.
 
KEW

KEW

Audioholic Overlord
Are these sold out?
I was thinking about getting one if the price was good, and they show sold out on the main site, but I wasn't sure if there was a different place I need to go for a flash sale item.
Well, DUH!
What is wrong with newegg! Don't they know that Eastern standard time is the default for the US?:p
Works fine for me now that it's after 9 o'clock Pacific time! I did sign up for a flash sale alerts. Not sure if that is required to see and buy flash sale items.
 
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Pogre

Pogre

Audioholic Slumlord
LOL!

Yeah, every now and then if I touch a paper bag a certain way, I kind of get that odd feeling too. Didn't know that was "a thing".

But, ONLY paper bags for me, not cardboard or anything else.
Paper bags are definitely the worst. Something about the dryness and texture. My dad was like that a little too. Boxes are unpleasant too, but paper bags... *shudder*
 
G

Gooddoc

Enthusiast
LOL!

Yeah, every now and then if I touch a paper bag a certain way, I kind of get that odd feeling too. Didn't know that was "a thing".

But, ONLY paper bags for me, not cardboard or anything else.
Strange. Chalkboards don't bother me a bit, but stocking like materials get me. Just thinking about it can make me shudder. It makes me wonder the "why" of that. Must be some kind of evolutionary thing.
 

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