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You will?
Ok... Challenge accepted! ;)

Put your cards on the table, let's see what it can do then.

116.7dbZ @ 10hz nearfield is the number to beat, as per video.

Note: 1 clone was used for power. So any amp up to 8-9kW is acceptable by me. Heck, go more watts than that if you think the 24 needs it, I don't mind. Only SPL matters right?
http://www.youtube.com/watch?v=xyclUbKK0nQ

Now... I made this public video over a year ago, so it's not like the abilities of 4 LMS-18's are some Area51 top secret cola-ingredients that nobody knows about. (Just sayin')

My only condition, is that you must use a good mic or SPL meter.
A TermLab, an SPLlab, a UMIK-1 or CM-130 etc etc (something at least half-decent, well known, verifiable, and preferably calibrated.)

The challenge is open to any owners of a sealed or IB'ed 24.
Well ok, nick is coming up on friday with a new mic and his equipment. We shall see. I have an inuke 6000 on them. He is going to abuse them and take them to any limits we can get to.

Just a question though. Forgive my ignorance but wouldnt it make sense to look at more than a 1 spl number at a certain frenquency. Again, does it mean a speaker isnt good if mine can pick up 5 or 4 hz when another speaker can't. Point is room, power source material can make a difference as well. But the challenge is there. We shall see.
 

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You realize he pointed out that you were wrong right? 5 is pretty different from 3 and take the fact the unimax isn't the LMS, UXL or HST as they will match the high xmax of the 24 where as the unimax doesn't
Did you not see that I stated that? I said I may have overstated it saying 5 verses 3. Excuse me.
 

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Did you not see that I stated that? I said I may have overstated it saying 5 verses 3. Excuse me.
I say this with complete sincerity, my apologizes if I derailed this thread. My point in writing anything was to say these subs shouldn't be discounted or snubbed because they are not the normal. Honestly I know what was stated as to the absurdity of the challenge laid down and quite frankly I could care less if my system doesn't equal the stated point of reference because I can't get these subs off 50% power on this amp nor can I get to 0 on the dial on the receiver. I love my 2 24s as much as others love their marty cubes, or sealed corinthians. However, 24s, no matter SI or AE are a different way to get bass bliss.

I do look forward to seeing how these two speakers are different and what they can do.

And also it isn't a bad thing or an attack on anyone if one sub has more impact ot the same impact as few of another size. I like the look of 8 18s in a room in either ib or cabinet drivers. Its impressive no matter how you look at it. Personally I like the look of no subs in the room as well and why I chose IB.

Interestingly enough we are comparing a group of subs that destroys anything commercially available at many times the price. We are fortunate to be a part of a niche group that can fuss over 4 18s or 2 24s. Funny when you stop and think about it. LOL.

The only that will happen with these news subs is the envelope will get pushed further and the speakers will keep getting better.
 

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i haven't seen anybody discounting or snubbing anything.
i haven't seen anybody suggest the 24" is 'no good' either.
some folks just responded to the hyperbole regarding the performance of the 24".
at least as far as i have observed.
 

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Discussion Starter #66
Superfrog, the claim was the only thing that was disputed, not the driver. Lots of us on here have more bass that 10 rooms need. It's good you like your drivers and you should, they're great.
 

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wouldnt it make sense to look at more than a 1 spl number at a certain frenquency. Point is room, power source material can make a difference as well. But the challenge is there. We shall see.
True. But I don't have a meter that can take sweeps at +141db though, I'd have to measure it groundplane outdoors at 600ft away. ;)

The UMIK maxes out at 130-ish dbZ.

Here is another frequency, the LMS can output more but I didn't want to smoke them or have cops show up. I thought this was sufficiently loud enough.


quad LMS in 24cubes and 8800watts gives:


 

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sd of 24 is 2129 cm^2, sd of say an lmsu is 1195 cm^2. The physics here, is that two lms will have 261cm^2 more surface area and greater power handling by no small margin. Going by models, the 18s have the clear advantage. Watt for watt, 2 of the 18s will have greater output than a single 24. Factor in the greater power handling capabilities and lower inductance, and they pull ahead even more, while operating in a smaller enclosure. This doesn't take anything away from the 24. For sealed cabs, it's a great driver, especially in the current higher end market. LMS is MIA, UXLs are hard to come by, Aurasounds are overpriced. That doesn't leave too much to pick from.
 

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True. But I don't have a meter than can do sweep measurements at +141db though, I'd have to measure it groundplane outdoors at 600ft away. ;)

The UMIK maxes out at 130-ish dbZ.

Here is another frequency, the LMS can output more but I didn't want to smoke them or have cops show up. I thought this was sufficiently loud enough.
You don't need to do measure sweeps at that level, you just do measurements outdoors at a greater distance and do some math. Every doubling of distance you're losing 6db. At 10 meters, you're down 20db.
 

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not, the usable excursion on the 24 is upwards of 50mm according to josh/data-bass, so that is where it gets a little closer to 3 units vd.
 

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You don't need to do measure sweeps at that level, you just do measurements outdoors at a greater distance and do some math. Every doubling of distance you're losing 6db. At 10 meters, you're down 20db.
Ricci has done a good job of measuring the LMS's already I figure; I wouldn't want to repeat his tests with my lesser-gear.
I will let frog do the math if he wants, I'm too busy listening to music. hehe :D
 

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not, the usable excursion on the 24 is upwards of 50mm according to josh/data-bass, so that is where it gets a little closer to 3 units vd.
It takes a minimum of 8kw in a 10 cube box to push it that far. I don't think that coil would like that very much. In a 20 cube box you can get there with minimum 4kw, and less in an IB. Assuming it can reach 50mm ok, this gives it a 1.5db advantage at 20hz and below. I have no experience with how this driver sounds at that excursion level, but I've yet to hear a driver run clean at that amount of excursion. They're even at about 30hz, but above 30hz the pair of 18s pulls away due to the increased power handling and non-excursion limited displacement. This was modeling with LMS ultras since I had it handy.

Comparing to some Zv4 18s or HST18s, which have greater excursion potential, they will model nearly identical to the 24 on the bottom end, and still pull away up top due to the increased power handling.

Keep in mind, I'm not trying to be a naysayer here, just trying to keep some logic in the discussion. It's interesting discussing drivers this large. I considered going with large drivers before my switch to ported, but ported boxes just yielded more output where it matters (imo). The SI doesn't do well ported, but if AE puts out a 24" driver that models well in a low tuned ported enclosure, that would be something ;) Still, would need a monster coil and increased power handling to keep up with a pair of 18s above 20hz, which will also likely operate in a smaller cab.
 

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not, the usable excursion on the 24 is upwards of 50mm according to josh/data-bass, so that is where it gets a little closer to 3 units vd.
That's not how I read it. From data-bass.com -

At around 3” peak to peak ... the surround was starting to dimple visibly.
That's about 76 mm p-p or 38 mm one way.

If the surround is visibly dimpling the driver is already into heavy distortion. I've never seen a driver sound good when pushed that far.

Even if it could do 50 mm usable excursion I doubt the driver could handle the power required to push it that far. (Yes, I realize Ricci did push it that far, but that was in free air and he specifically chose a frequency close to fs so it didn't require much power to do that, and he probably didn't push it that hard for very long.) Mark Seaton said he blew this driver in 30 seconds with a 4000 watt amp (so it was probably putting out less than 4000 watts at the time).
 

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Mark Seaton said he blew this driver in 30 seconds with a 4000 watt amp (so it was probably putting out less than 4000 watts at the time).
How does one blow a driver rated for over 1400watts RMS in just 30 seconds?

He was either trying to intentionally damage it:
Mark: Do you smell smoke and hear clacking?
BassThatHz: Yes
Mark: Ok, let's push on then.
ROFL! :D

or he did it purely-by-accident. (messed up gains with too much input signal me thinks!)
or he did it just so that he could say that he DID; or was he lying? (i.e. marketing & sales)...

So which is it? :D
 

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dsg, maybe it is more maybe it is less. i was referring to this:
"...it is definitely in excess of 45mm before anything is in danger of physical contact with other parts."
ymmv.


 

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How does one blow a driver rated for over 1400watts RMS in just 30 seconds?

He was either trying to intentionally damage it:
Mark: Do you smell smoke and hear clacking?
BassThatHz: Yes
Mark: Ok, let's push on then.
ROFL! :D

or he did it purely-by-accident. (messed up gains with too much input signal me thinks!)
or he did it just so that he could say that he DID; or was he lying? (i.e. marketing & sales)...

So which is it? :D
The only details I know are that it was a 4000 watt amp and the driver lasted 30 seconds. I have no idea why he would do that but I doubt it was marketing, that's a really bad way to sell drivers (he sells them, doesn't he? - I'm not sure.) And I think he's experienced enough to set gains properly. I'm also relatively sure he's experienced enough to know that what he was doing would melt the coil (I could have told him that would happen), so I have no idea what he was up to. You'd have to ask him.

Anyway I'm not surprised, as I've said before I'd be really surprised if I wasn't able to blow this driver with a Behringer EP2500 in a few minutes with the right program material.

Anyway, what is the SI 1500 watt RMS rating based on? What testing was performed to determine that rating? A lot of pro drivers have to be able to survive the manufacturer's rated power with an bandwidth limited AES signal for 2 hours to earn their power rating. I'm sure the SI driver could pass that 2 hour 1500 watt AES signal test, but RMS is twice as intense as an AES signal (3db crest factor vs 6 db crest factor). I'm not sure the SI driver could survive 1500 watts RMS (sine wave) for two hours, so I'm not sure what the power rating is based on. But since there's no real industry wide power rating standard the manufacturer is free to use whatever number they like for a power rating. Also, RMS and AES are regularly confused, Parts Express always lists RMS even when the manufacturer power rating is specified as AES, which is a HUGE difference and a big mistake.
 

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dsg, maybe it is more maybe it is less. i was referring to this:
"...it is definitely in excess of 45mm before anything is in danger of physical contact with other parts."
ymmv.


Sure, you can push it that far. But I'd bet it sounds pretty nasty already at 35 mm if the surround is dimpling.
 
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