MKtheater Posted February 22, 2016 Report Share Posted February 22, 2016 Luke, I think once you run a scene with the LT engaged you will realize you don't have to run the LFE as hot anymore and if you do, be careful. I have no problems but I have a fail safe in my breaker which will trip if too much power is used before anything gives up. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 22, 2016 Author Report Share Posted February 22, 2016 Luke, I think once you run a scene with the LT engaged you will realize you don't have to run the LFE as hot anymore and if you do, be careful. I have no problems but I have a fail safe in my breaker which will trip if too much power is used before anything gives up. If I had bigger amps I could definitely have a really bad day if I weren't careful, but as it sits now the pair of CC5500 doesn't have enough power at any frequency to pose any threat to these 21s. Link to comment Share on other sites More sharing options...
Infrasonic Posted February 22, 2016 Report Share Posted February 22, 2016 I would be surprised if that scene hasn't killed a few amps too. I bet most amps simply protect or heavily limit the output with it. Anybody want to try this scene full out with an Inuke? I bet it doesn't go well. I do "fine" with my system as it is limited at the wall. I simply trip a breaker if I push this scene. Luke will be TOTALLY fine with his current system, no matter what LT amount he wants to use. Link to comment Share on other sites More sharing options...
Bossobass Dave Posted February 22, 2016 Report Share Posted February 22, 2016 ... Link to comment Share on other sites More sharing options...
Ricci Posted February 22, 2016 Report Share Posted February 22, 2016 Luke after looking at your close mic it appears that there is still some effect from nearby boundaries apparent in the response on the low end or possibly from the other driver or drivers running. Not too big of a deal. You can probably smooth it a bit more and get a clearer picture of the general shape. Did that measurement have a high pass filter engaged? Appears to be a pronounced inductance hump in the response but that is expected. If there is a high pass it would exaggerate that somewhat. Your impedance curve was in box? If so it indicates the in box resonance as about 36Hz which would indicate that the driver free air resonance is quite a bit lower than that. You won't have anything to worry about with the 8 21's until you get 2 big dog amps powering them, at which point a little testing for system limits may be in order. Even being somewhat underpowered currently you should have enough there to WAY overshoot REF at the seats. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 22, 2016 Author Report Share Posted February 22, 2016 Luke after looking at your close mic it appears that there is still some effect from nearby boundaries apparent in the response on the low end or possibly from the other driver or drivers running. Not too big of a deal. You can probably smooth it a bit more and get a clearer picture of the general shape. Did that measurement have a high pass filter engaged? Appears to be a pronounced inductance hump in the response but that is expected. If there is a high pass it would exaggerate that somewhat. Your impedance curve was in box? If so it indicates the in box resonance as about 36Hz which would indicate that the driver free air resonance is quite a bit lower than that. You won't have anything to worry about with the 8 21's until you get 2 big dog amps powering them, at which point a little testing for system limits may be in order. Even being somewhat underpowered currently you should have enough there to WAY overshoot REF at the seats. For that close mic measurement I set the HPF to 250hz on my processor. I wasn't surprised with the inductance hump and I'm sure you weren't either. I don't think there are any shorting rings in these drivers, and with my planned crossover points it wasn't of much/any consequence. That particular cabinet for the impedance curve has the most play time on it, probably 4-5 hours of heavy use plus the 30 minute free air break in, so the CMS has definitely increased from when I first got them. I'll take another impedance sweep in a few weeks to see if it drops any further but I'm doubting it will drop much lower. Maybe 1-2hz. Reference at the seats, even with that first LT boosting ~10db at 10hz and lower, was still cake. One of those WCS scenes I tested was the dragon crash at the very end of HTTYD and even reference + LT + another 6db was still fine but approaching power limits of the amps. I see two SP2-12K on the horizon. Link to comment Share on other sites More sharing options...
d_c Posted February 23, 2016 Report Share Posted February 23, 2016 Oh man, that chopper scene from Lone Survivor is awesome. I used that for the KC gtg last year for the 24s. They get moving big time. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 23, 2016 Author Report Share Posted February 23, 2016 I think I'll series the Othorns and put them on a single bridged CC5500, move the SP2-12K to 4 of the 21s and buy another SP2-12K for the other 4. I sold the 7.5 and I'll also sell the other CC5500 to help fund this. Link to comment Share on other sites More sharing options...
MKtheater Posted February 23, 2016 Report Share Posted February 23, 2016 Yeah, as for efficiency I am talking room gain. My system is different because I have an IB and I don't require that much power to reach high levels. Of course I lose some upper end for this but 12 18s in a closet sized sealed room helps a bit. Link to comment Share on other sites More sharing options...
Ricci Posted February 23, 2016 Report Share Posted February 23, 2016 I think I'll series the Othorns and put them on a single bridged CC5500, move the SP2-12K to 4 of the 21s and buy another SP2-12K for the other 4. I sold the 7.5 and I'll also sell the other CC5500 to help fund this. A reasonable plan. Link to comment Share on other sites More sharing options...
BeastAudio Posted February 23, 2016 Report Share Posted February 23, 2016 I would be surprised if that scene hasn't killed a few amps too. I bet most amps simply protect or heavily limit the output with it. Anybody want to try this scene full out with an Inuke? I bet it doesn't go well. Oh yea, the peavey and crest will go into protect nicely with this scene. They make it through just fine still at reference levels flat. It's when you are cruising at 10dB hot or more that the real issues arise. Wanna know what else doesn't like that scene? haha. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 23, 2016 Author Report Share Posted February 23, 2016 Oh yea, the peavey and crest will go into protect nicely with this scene. They make it through just fine still at reference levels flat. It's when you are cruising at 10dB hot or more that the real issues arise. Wanna know what else doesn't like that scene? haha. lol Link to comment Share on other sites More sharing options...
tuxedocivic Posted February 23, 2016 Report Share Posted February 23, 2016 Inside joke? I like that scene. Makes the choppers feel really realistic. I don't listen at reference so I haven't had troubles with it, but I could see it really being a power suck at reference level! Link to comment Share on other sites More sharing options...
Infrasonic Posted February 23, 2016 Report Share Posted February 23, 2016 Sorta. Dig well enough and you can probably figure it out for yourself. Link to comment Share on other sites More sharing options...
Stormwind13 Posted February 23, 2016 Report Share Posted February 23, 2016 I really need to get off my ass and come check it out. Link to comment Share on other sites More sharing options...
Rowan611 Posted February 23, 2016 Report Share Posted February 23, 2016 Inside joke? I like that scene. Makes the choppers feel really realistic. I don't listen at reference so I haven't had troubles with it, but I could see it really being a power suck at reference level! Referring to Beasts GTG where that scene didn't play well with 24" drivers. Link to comment Share on other sites More sharing options...
NWCgrad Posted February 24, 2016 Report Share Posted February 24, 2016 That can not be confirmed or denied..... Link to comment Share on other sites More sharing options...
Electrodynamic Posted February 24, 2016 Report Share Posted February 24, 2016 Referring to Beasts GTG where that scene didn't play well with [edit] one 24" driver and large amount of clipped power. [/edit] Fixed. One driver, one scene, no protection at the time, too much clipped power. Definitely clipped 4,000 watts (8,000 watt heat signature to the coil) is no bueno for one driver. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 24, 2016 Author Report Share Posted February 24, 2016 There's a couple different versions of that story floating around Link to comment Share on other sites More sharing options...
SME Posted February 24, 2016 Report Share Posted February 24, 2016 No system is efficient @ 5 Hz. A rotary woofer system is *very* efficient at 5 Hz. It just has other drawbacks. Link to comment Share on other sites More sharing options...
Electrodynamic Posted February 24, 2016 Report Share Posted February 24, 2016 There's a couple different versions of that story floating around Want to put your money where your mouth is and send over a Judge 21 to be put through the exact same situation to see which driver last longer, plays deeper, etc? Same size box. Same clipped power. Exactly the same. I'm all for it. Your drivers are seeing far less power [per driver] than the single 24 was being sent during the GTG. Or maybe you enjoy riding the "that's what she said" gossip train. Send in one of your drivers and we will clamp everything and measure everything in the same size sealed enclosure. All equal. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 24, 2016 Author Report Share Posted February 24, 2016 Want to put your money where your mouth is and send over a Judge 21 to be put through the exact same situation to see which driver last longer? Same size box. Same clipped power. Exactly the same. I'm all for it. Your drivers are seeing far less power [per driver] than the single 24 was being sent during the GTG. Or maybe you enjoy riding the "that's what she said" gossip train. Send in one of your drivers and we will clamp everything and measure everything. All equal. I can only think of 1 or 2 drivers that might be able to take 4kw of a 6.5hz sine wave for a full minute, and the IA Judge isn't in that list. It doesn't take 4kw of clipped power for a full minute to fry a rugged and well designed/built driver. 4kw of clean power for the same minute will do that job just fine. Link to comment Share on other sites More sharing options...
Ricci Posted February 24, 2016 Report Share Posted February 24, 2016 A rotary woofer system is *very* efficient at 5 Hz. It just has other drawbacks. Some day I have plans to DIY one of these or at least hear one. Link to comment Share on other sites More sharing options...
BeastAudio Posted February 24, 2016 Report Share Posted February 24, 2016 A rotary woofer system is *very* efficient at 5 Hz. It just has other drawbacks. Like a closet sized back box yea Josh, I want to try one out too someday. I have the place to do it with that storage room beside the theater...although that might not even be big enough according to Thigpen. Link to comment Share on other sites More sharing options...
Ricci Posted February 24, 2016 Report Share Posted February 24, 2016 No typical driver takes full power from that torpedo amp into the impedance minimums for very long. Doesn't matter what driver it is. Heat build up will be too much for the coil. They can't really dissipate that much power long term. Deep in the Ipal literature there is some information on suggested settings for setting the long term average power limiter to ensure absolute safety from thermal damage to the Ipal 21 drivers. It's suggested that it be set at 700w. Keep in mind that's a 6" coil driver with really good venting in the motor and a verified 2500w AES power test rating. 700w sounds awful low doesn't it? Well that's a true long term average power measurement. You can watch a whole host of things such as peak voltage/current/power and long term for all 3 as well, in real time, in the dsp. You can push the system up to the point where the amp (8500w peak) is tapping out on the peaks on demanding bass music and the driver is pounding away and then have a look at the long term average power display and it's a few hundred watts. It's eye opening. If a sustained signal like a sine wave comes in the output power will be reduced to 700w after the threshold setting is met (could be a fraction of a second to a few seconds depending on the setting.). That is to save the driver from excessive heat buildup in the coil because those types of power levels are too much even for this driver. There are also generic suggestions for setting the long term average power clamp for generic pro drivers based on the coil diameter and power rating and they are even less. Link to comment Share on other sites More sharing options...
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