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lukeamdman

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Everything posted by lukeamdman

  1. lukeamdman
    You owe me one shreds...I did this with the wife home because I was so curious... I measured a steady 86.5v without clipping and registered 131.1db with one Othorn at the LP (compromise with the wife was that only one horn would be on =) ). Going up one more DB in the volume resulted in 88.0v, 132.0db, and clip lights.
  2. lukeamdman
    Looks he had it for sale but no mention if it actually sold: http://www.avsforum.com/forum/209-audio-gear/1970642-fs-speakerpower-sp2-8000-rack-mount-sub-amp.html
  3. lukeamdman
    I thought he sold that amp?
  4. lukeamdman
    It's a track by Bass Launch called "Earth". This one particularly is the "low and slow" version. Most of the tracks on that whole album are similar to this. I'm not sure if there would be any difference between playing my 6 second loop of this track or a 27.5hz sine wave from REW. For the voltage, do you want me to capture the voltage at the binding posts while playing that track loop at a level where the amp begins to clip? The Fluke 117 is called a "True-RMS" meter, so I'm not sure if simply getting the AC voltage is all you're after.
  5. lukeamdman
    I just posted the SpecLab captures of the music track I used for testing in my theater thread. Go take a look.
  6. lukeamdman
    Count me in! The wife would never turn down a surprise trip to NC/SC =)
  7. lukeamdman
    It remains a mystery what happened with the SP2-8000 and the HS-24. Everyone was shocked by the outcome, although no one is denying it happened. I admit I was a bit cranky when asked for all the additional information about my 1ohm claims, but I’ve learned a lot in the last week so I’m glad I dug into it deeper. I found out my favorite dubstep demo track wasn’t anywhere near 1ohm but rather even over 2ohm in fact once measured. I also confirmed (at least to myself) that on the very next track I picked with 27hz content that a consistent ~1.2ohm load is being presented to the amp many times throughout that track. I’ll provide a SpecLab capture of the track and also of my several second loop of the track which I used for the voltage/amperage capture. Me merely providing a DCR of a driver and a track name wasn’t enough info for you, and I get why after the last week of impedance measurements I performed. However, this is exactly the limited information you’ve provided about the SP2-8k/HS-24 debacle. We have a DCR of the driver, and a track name from “imagic” on AVS. I imagine if someone stated something like “We bridged an A14K to a single driver with a DCR of 2.9ohm and got it to mute the outputs on “tracknamehere” you’d understandably want more information such as the exact things I’ve been asked for in this thread: Speclab captures of the track, voltage and amperage draw from the amp, and a RMS voltage from the amp while at the limits. Maybe even a voltage reading from the mains to see if there was voltage drop? That information was never gathered and can’t be provided from this GTG a few years ago, so it’s going to remain a mystery. If it were the A14K in that scenario with the same limited information, you wouldn’t be happy it was brought up every time a A14K is mentioned because we simply don’t have enough information to know what caused it.
  8. lukeamdman
    I regret my snippy comment. I shouldn't have said it and I apologize. I allowed your posting style, which I would describe as frequently sarcastic and passive aggressive, to put me in a grumpy mood when I posted that. Won't happen again. Josh had direct experience with an IPAL in an Othorn, so if he tells me the load drops to ~1.1ohm between 25-30hz, why should I doubt him? Before purchasing the SP amp I was also chatting with Brian, who I found out also had experience with this specific driver, so naturally I had some questions for him. I also PM'd you about the A14k during this time as that amp was on my list of potentials for this specific project. Do you have some issue with me talking about some of the details of my casual conversations with Josh and Brian? I also don't see the problem with the 90A requirement that delivering 8kw into 1ohm would necessitate. My limited understanding is that the 8kw figure is a burst/peak wattage number like the rest of the Powersoft output specifications, and I also assume they recommend at least 240v/30A mains for that module. A 90A draw for a few fractions of a second shouldn't give a breaker that size any trouble, should it?
  9. lukeamdman
    If you want something specific, ask for something specific. We obviously weren't on the same page. The voltage for that will have to wait for another night when the wife is out of the house. You guys wanted measurements and I provided them. I went one frequency at a time to capture the impedance at each, and also captured the volts/amperage during a track which also lined up almost exactly with my graph. What's next after I capture this next thing?
  10. lukeamdman
    You want a random voltage at no specific volume level?
  11. lukeamdman
    Don't know. My meter can only read up to 10A.
  12. lukeamdman
    i purchased a Fluke 117 and also borrowed another Fluke meter from a buddy of mine so I could take amperage and voltage readings at the same time. I ran sine waves, one frequency at a time..., and started at 1 volt of output from the amp. However, that was getting too loud so I lowered it to ~.5 volts for the remainder of the measurements. Taking a measurement during one of my favorite dubstep tracks had an average reading of ~2 to 2.1 ohms, and after hooking up SpecLab, I found out what I thought was ~30hz was really ~33hz so that made sense. So, I tried another track, this one with several seconds straight of ~27hz, and the reading was a repeatable 1.217 ohms. I pushed this track to levels over 135db at the seats with just the Othorns playing and it resulted in no clipping and idle fans. Amp barely warm to the touch.
  13. lukeamdman
    After all that your dad dishes out on these boards, just look at his latest reply to SME a few minutes ago, he better be able to take a little back in return. I'd say my response was very tame, heck even AVS safe, compared to a lot that gets said around here. Are you saying that Josh measurements of the IPAL in the Othorn are just a theory? B&C's specs and my measurement of the DCR are just theory? Is it really that far out there to assume that when Josh measures a driver/cabinet combo to be ~1ohm from 25-30hz and some dubstep with near sine-wave like behavior in that same range would measure similarly? I'd be happy to measure the voltage and current, but I'll need a better meter. I have a Klein MM200 and it's the biggest piece of garbage I've ever owned. Any suggestions for a decent meter?
  14. lukeamdman
    My 8 and 6 year old had an argument with almost that exact same use of words. "If you're not going to let me play with your toys I won't want to play with them anyway!!" Josh measured the IPAL in the Othorn but didn't publish the results of any of it. At the time B&C didn't want him to share any information at all about it, not even him sharing he had the drivers period. He said the impedance minimums were at the same points. 29-30hz is right where the lowest bass line for my favorite dubstep demo track is, and it basically holds that frequency for 2-3 seconds straight. 59-60hz is right in the wheelhouse for drum kicks. It seemed obvious to Josh and Brian that the use of this particular driver would cause problems for a lot of amps, and Powersoft eve made an amplifier module just for this driver rated at 8000w into...you guessed it...1ohm. I'm fine with it that you don't think I'm approaching 1ohm loads, but it's up to you to prove I'm not if you're really that concerned about it.
  15. lukeamdman
    Dedicated 240v 30A. So the B&C specs of the driver combined with Josh's impedance measurements of the same driver in the same cabinet just don't do it for you huh?
  16. lukeamdman
    Here are the drivers I'm using: http://www.bcspeakers.com/products/lf-driver/21-0/21ipal They have a DC resistance of 0.7ohm, and I also measured 0.7ohm with my meter. In Josh's measurements of the Othorn cabinet with the 21sw152-4 (DC resistance of 3.3ohm), the impedance minimums are at about ~28hz and ~59hz 28hz: 3.8ohm 59hz: 3.9ohm 21sw152-4 specs: Josh also tested the 21-IPAL in the Othorn cabinet and stated the impedance between 25-30hz to be ~1.1ohm.
  17. lukeamdman
    Awesome information Josh! I don't think Dave believed me when I was telling him how powerful the sp2-12000 was, but these tests shouldn't leave any question. As you know, I'm running mine to loads very close to 1ohm per channel, and it never complains. I've seen the fans skin up maybe twice in the last year I've had it. I've said it before and I'll say it again, unless you plan to use the SP amps for strictly 2ohm use you're wasting their potential and what they were really designed for.
  18. lukeamdman
    Awesome! Really looking forward to the results.
  19. lukeamdman
    The Party Marty.
  20. lukeamdman
    Do you mean the crest looks cleaner and doesn't have those blinding blue lights?
  21. lukeamdman
    (2) B&C 21sw152-4 21" drivers - **SOLD** $575 shipped each. I used these in my Othorn cabinets for about a year and they're in perfect shape. I bought them new and they'll ship in the original boxes. Crest CC4000 amp - **SOLD** $575 shipped. Purchased new less than 1 year old. Includes original box, manual, and warranty card. Crest CC2800 amp - **SOLD** $475 shipped. Purchased new less than 1 year old. Includes original box, manual, and warranty card.
  22. lukeamdman
    I'm putting mine in 9cu.ft cabs ported to 30hz. I bought the 8ohm coils so I could parallel two to a single channel of a pro lite 7.5. That means they'll be getting less than 1kw worst case, and with a 4th order BW filter at 24hz, excursion never exceeds 14mm even with 1kw. I'm really hoping those 2.5" coils are as good as they claim for heat dissipation...
  23. lukeamdman
    Whatever happened to your AE TD18H+ drivers? You mentioned one of them had to be sent back to AE 3 times or something? Something was wrong with the coil causing the FS to be too low? i ordered some for my new mains, and almost 6 months later I have yet to take delivery on them.
  24. lukeamdman
    What kind of content were you playing when the amp went into protection?
  25. lukeamdman
    Since Mark posted this in one of my threads on AVS, I don't think he'll care if it's posted here as well. This comment is in regards to SpeakerPower amps: With a reasonably stiff power line, you won't see any sag all the way to around a 1.5 Ohm minimum impedance. Below there you will see some current limiting and reduced maximum power, but it will still work just fine. When I was testing a dual 2 Ohm HS24 with coils paralleled, I left too little time between test runs with a 12-14Hz sine wave in a smaller sealed box, and the SP4k melted the wire right off the former driving the 1-1.5 Ohm impedance. I know a few guys at a GTG tried to blow a HS24 by wiring each coil of the sub to each channel of a SP2-8k. They noted the amp went into protection mode before the HS24 gave up, but I'm willing to bet that voltage drop on the AC going to the amp was the cause of that. Mark smoked the coils with a SP amp that's essentially half of a sp2-8k in plate amp form.
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