lukeamdman Posted February 19, 2016 Author Report Share Posted February 19, 2016 Do you have any data to support the idea that Fs will drop 1/2 an octave after 100 hours vs 1 hour? And, if that were possible, how exactly would that audibly reduce HD <20 Hz? The only thing that will change from out-of-the-box is Cms. That will affect Vas and Fs pretty much inversely, netting a basic wash in in-box native response with no audible change in HD. What you're suggesting is a radical change after some magical great length of use. This is new info for me and I'd be interested to see the actual reasons and data, if possible. During my conversations with Nick, he was very clear that the specs listed for their drivers are AFTER a very lengthy break-in process. This is how he specifically designs them. He suggested it would 2-3 hours of use per day for 3-4 weeks before they're approaching final specs. On one of my drivers freshly built, the Fs was 36hz. After several hours of free air break-in (with 1,000w RMS), he measured the driver parameters again to make sure it was breaking in appropriately and repeated this process quite a few times. According to his simulations and the readings he took periodically during his manual break-in process, he determined the final Fs would be ~26hz. Once broken in, those specs aren't going to change much if any even after years of heavy use, and that's his goal. In "stock" form, the final Fs for these drivers is ~35hz after this lengthy break-in, but my drivers have different spiders and also 3 dust caps to add MMS. Of course the goal for softening the suspension and adding mass was to lower the Fs. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 19, 2016 Author Report Share Posted February 19, 2016 Two MORE? So he'd have, like THREE TOTAL? It's very possible Link to comment Share on other sites More sharing options...
lukeamdman Posted February 19, 2016 Author Report Share Posted February 19, 2016 Link to comment Share on other sites More sharing options...
lukeamdman Posted February 19, 2016 Author Report Share Posted February 19, 2016 Link to comment Share on other sites More sharing options...
Nate Hansen Posted February 20, 2016 Report Share Posted February 20, 2016 lol Luke wtf. I haven't been keeping up with the audio forums like I used to. Get rid of a couple of the beast nuclear horn subs? Link to comment Share on other sites More sharing options...
lukeamdman Posted February 20, 2016 Author Report Share Posted February 20, 2016 lol Luke wtf. I haven't been keeping up with the audio forums like I used to. Get rid of a couple of the beast nuclear horn subs? I sold the Ghorns Link to comment Share on other sites More sharing options...
SME Posted February 20, 2016 Report Share Posted February 20, 2016 The only thing that will change from out-of-the-box is Cms. That will affect Vas and Fs pretty much inversely, netting a basic wash in in-box native response with no audible change in HD. What you're suggesting is a radical change after some magical great length of use. This is new info for me and I'd be interested to see the actual reasons and data, if possible. Fs can be determined from Cms and Mms only. This means that If Cms increases and Mms doesn't change, Fs must decrease. This is not a wash. I don't see any reason why the break-in recommended for these woofers is unreasonable. Physically speaking, the time required for mechanical break-in could vary from anywhere from instantaneous to 1000s of years or more, depending on the material and construction. There's nothing magical here at all. What can be said is that if the break-in time is especially long for any particular suspension, then its usefulness diminishes and it is less likely to be made or sold. In this case, I'd be concerned that 100 hours isn't long enough for break-in if the drivers aren't being pushed hard enough. Now about that distortion. Realize that Cms is only really a constant value if the excursion is very low. As excursion increases, Cms usually decreases gradually to a point beyond which it drops off a lot. The longer the stroke, the more the non-linearity of Cms comes into play. It seems perfectly reasonable to me that a broken-in suspension may exhibit more linear Cms than one that is not broken-in. It's also possible that the reverse may be true for some cases. I don't know. There is another reason distortion may drop though. As Cms increases with break-in, its influence on the compliance of the box-mounted woofer diminishes relative the influence of the box air spring. This means that the deviation from linearity in Cms makes less contribution to the non-linearity of in-box compliance with the broken-in woofer, which in turn will tend to reduce distortion. Link to comment Share on other sites More sharing options...
Bossobass Dave Posted February 20, 2016 Report Share Posted February 20, 2016 ... Link to comment Share on other sites More sharing options...
lukeamdman Posted February 20, 2016 Author Report Share Posted February 20, 2016 You missed the point. If Cms rises... so does Vas. When Vas rises and Fs drops, there is a wash in native response and a loss in sensitivity. Sorry, but HD will not change audibly. What may be reasonable for you or others to assume is irrelevant. Feel free to unearth any data to support the claim. I just assumed with some pretty dramatic changes to the specs pre and post break-in that there'd be at least some change in the response. If that's not the case well I'm cool with that too. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 20, 2016 Author Report Share Posted February 20, 2016 Luke, I expect some parameters off of one of these drivers at some point. Impedance curve please! I'm betting an "in-box" impedance curve isn't what you really wanted, but here you go. This is from a single cabinet where the coils for each driver are in a series and then the two drivers are paralleled. I used my new fancy resistor rig to capture it. At 10hz and lower the numbers were fluctuating so I tried my best to get an average. This was around 3Vrms. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 21, 2016 Author Report Share Posted February 21, 2016 Ok, here's my first stab at the close mic measurement. I took this with only a single cabinet being powered, but I think with 3 other 21s that are literally within a foot of the one being powered I think it's affecting the response somewhat. I was expecting it to be a little smoother. I then put the mic at the LP and raised the volume level, but I'm not sure if I have the volume too low or too high? Regardless, it looks I have some really nice room gain down low. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 21, 2016 Author Report Share Posted February 21, 2016 Here's some sweeps at the LP with the 21s, Othorns, and mains all quickly integrated. There was a 12db volume difference from the very top sweep to the very bottom sweep. With 6 kids running around upstairs it affected the sub 10hz portion of the sweeps dramatically if they were jumping around, so this was the best I could do with all that noise. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 21, 2016 Author Report Share Posted February 21, 2016 Running the intro to Edge of Tomorrow at reference (subs 10db hot over the mains) resulted in less that 0.5" peak to peak excursion at the 10hz part... I think I have some headroom for a LT Link to comment Share on other sites More sharing options...
Rowan611 Posted February 21, 2016 Report Share Posted February 21, 2016 Luke, that looks pretty darn good!! How did EOT sound? Gotta be intense bro. How does the sweep compare to your sweeps with the Ghorns and Othorns? Link to comment Share on other sites More sharing options...
lukeamdman Posted February 21, 2016 Author Report Share Posted February 21, 2016 Luke, that looks pretty darn good!! How did EOT sound? Gotta be intense bro. How does the sweep compare to your sweeps with the Ghorns and Othorns? Sounds great, and I'm getting some vibration from the riser at the 10hz part too which is cool. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 21, 2016 Author Report Share Posted February 21, 2016 First experiment with a LT: Link to comment Share on other sites More sharing options...
maxmercy Posted February 22, 2016 Report Share Posted February 22, 2016 That is a SIGNIFICANT change. Hope your house is ready. Careful you don't clip the amps or the DSP, you are boosting 10dB, which = 10x the power demand. JSS Link to comment Share on other sites More sharing options...
dgage Posted February 22, 2016 Report Share Posted February 22, 2016 Why don't you try the subwoofer destroyer track, I mean the Lone Survivor Chopper scene? Be careful because the 6Hz signal is 10dB louder than the rest of the track according to the crack research done by Shredhead. Link to comment Share on other sites More sharing options...
Rowan611 Posted February 22, 2016 Report Share Posted February 22, 2016 Luke, do you have Lone Survivor on your HTPC? If not, let me know. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 22, 2016 Author Report Share Posted February 22, 2016 Luke, do you have Lone Survivor on your HTPC? If not, let me know. No. Link to comment Share on other sites More sharing options...
Ricci Posted February 22, 2016 Report Share Posted February 22, 2016 Why don't you try the subwoofer destroyer track, I mean the Lone Survivor Chopper scene? Be careful because the 6Hz signal is 10dB louder than the rest of the track according to the crack research done by Shredhead. 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. Link to comment Share on other sites More sharing options...
Fatshaft Posted February 22, 2016 Report Share Posted February 22, 2016 Luke, Try the Dragon Blade scene I sent you and watch those subs flabbing their brains away. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 22, 2016 Author Report Share Posted February 22, 2016 That is a SIGNIFICANT change. Hope your house is ready. Careful you don't clip the amps or the DSP, you are boosting 10dB, which = 10x the power demand. JSS Yeah I need to modify the LT a bit. I wanted to get flat to 10hz but I'm also boosting below that by quite a lot. 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. Ha, I could try it with the nu4-6000 but I don't want it to go up in smoke. Luke, Try the Dragon Blade scene I sent you and watch those subs flabbing their brains away. Oh yeah! I completely forgot about that one! Link to comment Share on other sites More sharing options...
MKtheater 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. It depends on the sub system and room. I have no problems running that scene with an INuke 6000 but my system is very efficient in that range. Link to comment Share on other sites More sharing options...
lukeamdman Posted February 22, 2016 Author Report Share Posted February 22, 2016 That is a SIGNIFICANT change. Hope your house is ready. Careful you don't clip the amps or the DSP, you are boosting 10dB, which = 10x the power demand. JSS Something like this might be more reasonable. Red is no LT, blue is the previous LT, and yellow is the latest LT test. Link to comment Share on other sites More sharing options...
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