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Bossobass Dave

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Everything posted by Bossobass Dave

  1. The Chase and PSA are very comparable, IMO. Otherwise, I would not have used it in my post. The drivers are essentially the same, from the same manufacturer and I have little doubt it would be evident in the test results if PSA ever submits a sub to be tested GP. My bad reading the 0 vs 0C. That obviously means a shitty driver version and, after looking at the results, I would not purchase it for any reason if the limit is a single driver, single subwoofer product. As far as the comparisons go, the max burst results are THD-limited. Does THD matter? With certain music source, probably. With HT, most definitely not unless there was a reference for comparison, which no one has available in his HT. Bottom line is that I would say the same thing about the PSA as I just did about the 0C version which is, basically; save your $$ until you can buy a good product. The 18.0 is a very good sub for a single sub/single driver target. The c and the PSA are not.
  2. Feel free to specify the voltage or whatever else you think is pertinent, with the corresponding graphs and commentary. I commented on the OP's Q regarding understanding graphs. When you start with a flat response, as the V1800 is designed to present, room gain will cause a bump at 20 Hz and the sub will compress below that at virtually any playback. Below tune, ported subs present noise. THD is shown in one of the metrics of the GP methodology, but below tune the ported sub's driver unloads. I guess most people still don't know what 'unloads' means in 2016. To repeat what I've said for millennia, the sealed sub will present a far more accurate reproduction in-room by any metric... period. Loud and/or loud over one particular octave of bandwidth is a different conversation. Attempting to combine the two is for others to discuss.
  3. The OP gives a choice of 2 subs and invariably gets suggestions for every sub but one of the two subs presented. Making sure I have the right comparo? I would personally use Josh's test results of the Chase vented 18 because: The PSA version is tuned lower than the Chase version and uses obvious EQ to alter the natural response whereas the Chase does not, but, as all of the suggestions will point out, the bottom line in any differences between the 2 subs in the OP's choices will be those at maximum output because of room size, LP distance, penchant for high dBSPL amongst members, etc. That means the PSA will show port compression and reversion to native response when pushed to its limits and the 2 subs will show similar end results, IMO. They both use almost identical drivers. One has a bit more amp but smaller box. They're both available in butt-ugly black. The differences between the Funk and the PSA will be classic regarding performance when referenced in the context of the decades-old ported vs sealed debates. There will be some output advantage across 1 octave, centered at the ported sub's tune and there will be nothing but noise below that and the sealed sub will exhibit the corresponding deficit around the ported sub's tune but offer usable output to single digits. That doesn't account for the vastly superior cabinetry and finish work by Nathan Funk and the much better driver and more powerful amplifier. This is where my opinion has always (and always will) tip the scales in any such choice. The Funk sub is truly furniture grade and awfully swell to look at and the PSA is a standard pro sound black pebble box. Here's an animation showing the THD comparo with a graph showing the max sweep and max burst comparos. There will be howls and jeers from the peanut gallery promising the superiority/huge differences between the Chase vs PSA ported 18" versions and vice versa, as usual, but... meh... this is my opinion which is always available to be proven wrong. My opinion is always biased toward the better product. Funk builds great subs that look great and perform well. This one is a no-brainer. Although it won't accomplish reference level with the sub at +18dB hot like most here prefer, the Funk 1 x 18" sub will offer far more accurate reproduction at reduced playback levels than any ported version with a lesser driver and amplification. And, it's stunningly executed in anyone's opinion.
  4. Yeah, and all you need is an SVS PB-13 Ultra because that 6.5 content is exaggerated by +20dB in SpecLab. Awesome.
  5. I don't know why, but I'm liking these movies with a twist on the original. This one is visually excellent and has serious low end, used sparingly but expertly, IMO. I also liked Abraham Lincoln, Vampire Hunter and Maleficent. Quirky, well done, well cast and acted and with superb sound. I also love the waveform analysis. Yet another great tool in the Data Bass bag. Props to His Shredness.
  6. The problem was a simple one; some folks took my post to mean that I actually think a K-20 on each single driver is required. How that's possible escapes me. Mike wondered aloud if it was sarcasm. Most saw it that way. I've mentioned many times in the past that I prefer to control excursion with air spring. That led to the Ilkka LMS-U uber-small 75L vs 200L box tests. It was my contention that the air spring is much more linear than other methods, like aggressive limiting. So, yeah, then there's more power available before X-mech and that power may cook the VC in the wrong hands. I've done many, many dozens of experiments in this arena, thus, I most certainly have strong opinions as to what might be ideal and how to tweak it from there. Let us know if you come up with any comparison method. It's an awesome thing when all that data can come with some instructions to aid comparison, for sure. The bottom line here is the question that remains, and it's a question that every sub DIYer faces. What is the proper power for the build? I agree that running dual bridged 220V amps is probably the right choice, and, in fact, that's what I've said to him privately, while all the chatter was raging. Meh, the whole teeth rattling, pants flapping nonsense has always irked me. Remember when the 25 Hz tuned 1x12" ported SVS sub was all the rage? People actually believed that sub could break a window, flap their pants, etc.! Are we all still in elementary school? It just saps credibility from the site to newcomers and foreign onlookers. I tend to view the threads from the perspective of the lurker who never posts because those are the vast majority of people who've PM'd me over the years. They far outnumber the posters and they lurk for golden info that they can and do use, internationally. The Marty's nuts foundation crumbling shit just confuses most of them. There's nothing wrong with fun stuff, it's just that for me the fun stuff is breakin' balls about fun stuff.
  7. Yes, most everyone got what I posted. For anyone who didn't, a simple question is all it takes. I was trying to steer the discussion to the signal chain. If one is spending the kind of stew it takes to birth a quad of Nick's King Of The Heap HS-24s, then extra ink might be warranted to nail down the preamp, signal shaping and amplification. It turned into a situation where Ricci seems to think he can throw any old paragraph at me and walk away, regardless of how mistaken he may be. I apologize for many times, due to a lot less time to spend in forums than I used to, being obtuse, but honestly the page that preceded my post was just a slew of "wow, your dick will fall off with that many subs!" posts (that shit has always been obtuse to me, sorry) and I thought the actuality of multiples should be mentioned. Contrary to what Josh posted, I get many PMs and e-mails asking about multiple driver systems and many include the misconception that each doubling of whatever driver Josh tests will result in adding +6dB to his output numbers. Use the wrong preamp and amplifier and you may buy 4 of whatever driver and yield LESS output than Josh's results with a single driver. Contrary to what Josh posted, most of them look only at the CEA output max numbers averaged over the bandwidth of interest. Hell, some manufacturers use those numbers to tout the superiority of their sub vs a competitor's and the masses split them like the Hadron Collider. They rarely even mention the compression sweeps results and generally ignore THD and compression altogether. I don't care what amp, box, copied methodology or presentation of the data is used by Josh or anyone else. Sad that he would think I do. I just prefer to post in a thread rather than answer the same Q a dozen times in PM. For the record, I disagree that 1 or 2KW per HS24 is sufficient. I've used more than that for each of Adire's 15" drivers with XBl^2 VCs, which have less power handling capability than a standard overhung VC. As Paul said earlier, we've never fried a VC. I still have a perfectly functioning Raven, loaded with a pair of Tumult MKIIs. Paul's never fried an amplifier, but I surely have. A Marathon MA 5050, an AA V6001 (three times) and various and sundry 5 to 8KW amps. I also disagree that the thread is derailed. The subject is important. If guys like Luke and Josh think the info is beneath them and post accordingly, then shit will hit the fan. But, there are people reading the info for the information that will filter through the ego tripping and posturing because it's good information.
  8. I seem to live in a parallel dimension. Please explain how one would use amplifier 'X' for only 50 Hz and up only? Not possible. The amp used is the amp used. According to conventional wisdom of this forum, all of Josh's DIY numbers are pretty useless because they are impossible to repeat in the real world. If you limit to sine wave sweep excursion at 10 Hz, you get power requirement 'A'. If you limit to sine waves-turned-square waves from a severely clipped signal to the driver while playing a scene from Lone Survivor (otherwise known here as "demanding material") you get power requirement 'B'. If you employ aggressive progressive limiters and high pass filtering, you get power requirement 'C' (the choice of 100% of commercial subwoofer designers). If you employ conservative hard limiter and no HPF, you get power requirement 'D' accompanied by a disclaimer for idiots. If you want to match Josh Ricci's Data_Bass THD-limited long term/short term 1/3 octave frequencies and 10-80 Hz averages and maximum sine sweep numbers, you need a K-10 on a dedicated 220V-50A line. Add additional amplifier as you double drivers if you want to add +6dB to those numbers each doubling... blanket... period. (There is no frequency band discrimination possible. Please explain what is the brain disorder that clouds this fact?) As for the GTG segment that Josh refers to as being "infamous" and is concluding involved material that was not demanding... If the HS-24 is being driven to within a hair breadth of X-mech when the 8000 watt amplifier on a dedicated 120V-30A line shuts down, exactly what should that scenario be referred to as if not demanding? That BS gets a complete pass while youse guys are still gnawing on the K-20/driver sentence? As for the scene in Lone Survivor, we can safely eliminate the 6.5 Hz portion of the source as the sub under test is down -18dB at 6 Hz. Paul and I are running a thorough examination of the data gathered and digits involved in the latest GTG incident that Josh has decreed was the result of demanding material in contrast to the infamous GTG incident. Adam, Paul & I had decided not to mention that incident at all but since Josh has let that cat out of the bag by referencing it here, after we run the conclusions past Dave, we may or may not discuss those conclusions. I'll just say again, citing any results from the antics involved at a typical GTG, good or bad, is no way for anyone to design a sub.
  9. Josh says this in his testing blurb: But in this thread he cites a 100% duty cycle combination of sines waves, run +15-20dB hot with triple digit harmonic distortion at the seats as the determinant of maximum amplifier power. And, he sticks by it. So, which is it? Is the top 2M GP sine sweep his metric or is a set of simultaneous 100% duty sines at whatever frequencies with a severely clipped signal his metric or is the fact that some people may regularly push any system beyond its capability his metric? Also, I have 9 selectable system response curves available for just this scenario. There's a 15dB difference between them. This is not new information and the debates for and against limiters vs selectable curves were many and thorough: There's a large disparity between the min/max bandwidth curves: Put another way for emphasis: For those who are impressed more with maximum dBSPL and not accuracy. Has Josh seen any of the data from the GTG he confidently cites as the reason Gage should use a 1000 watt amplifier, (or is it 2000 watts, but make sure you don't play Lone Survivor at +15dB hot) instead of the one that comes with the Mariana? Sorry, I'm gonna just piss on that thought a bit for how silly it is. Indeed. That's the million dollar question. One that carries the most weight, yet is NEVER addressed in these forums. The Hulk punch scene is an excellent choice, as is the missile stike scene in Bourne legacy. Many others are also good possible candidates and could be chosen by popular vote in a poll thread. And, as Yates showed years ago, speclab comparisons from digits to reproduced versions are both extremely helpful and easily accomplished. I guess it was the original statement that a K-20 is required for each driver to validate hundreds, if not thousands of comments that add +6dB for every doubling of drivers tested by Josh. Doesn't Dom's spreadsheet base sub performance on Josh's results of testing the SI HT-18? Of course, I'm correct and of course NO, I wasn't suggesting anyone do such an idiotic thing. Holy fuck, you guys, wake up... you really think that little of me? And, the frequency band in those comments is... IRRELEVANT... doesn't matter what frequency, you need to double the amp with the driver to get the +6dB per doubling... period. As I said in the original comment... "Yes, very likely". Mike had trouble discerning whether or not that comment was sarcasm? Well then, yeah, there would be a problem if that's the case. Silly^^^ If that's how it reads to Josh, he needs remedial reading tutoring ASAP. We all know that's NOT how it reads to him, he's just yankin' my chain for some unknown reason. But yes, I most certainly do recommend a 9K on a single DO HST-15 enclosure of the size used in the experiment. If I used Josh's metric, the amp would have been -6dB less power and would have severely clipped before seeing 45 mm one-way excursion during the HULK scene used as input. His suggesting that a 9K will fry the coils like the GTG incident caused roll eyes so severely that I still have a headache from it. Adam has a single Blackbird DO enclosure driven by a 9K. The drivers are 2-1/2" VCs and probably rated at 500W each. Ask him if he ever burned the VCs so badly that his guests were exposed to extremely toxic fumes for hours using only 1/4 of the amplifier's potential. With great power come great responsibility. That should go without saying in a forum like this one. Apologies for all of the confusion my simple statement of fact caused but it was to make a point that needs to be addressed here much more urgently than how to present the existing data in new ways, or whatever the latest fuss over fractions of decibel numbers is. Josh uses a ridiculous monster of an amplifier on ridiculously absurd mains to test every DIY driver... and he recently upgraded the amplifier to +3dB more power. The same results are not to be expected at any frequency using a Behringer NU or similar amp. It's bullshit to suggest otherwise, yet you guys tenaciously cling to these silly arguments with me to the contrary. The only case I'm aware of in which Josh used a shit amp vs his K-10 is the Chase vented sub: The below tune number is irrelevant, as it would be with any vented sub. The only number that didn't increase was the max excursion frequency. Overall, the sub a completely different animal with a real amplifier vs the POS it came with and anyone who disagrees can get bent right now. I don't recall Josh melting anything and for those who read all sorts of dumb shit into everything I post, I'm not suggesting that the K-10 on 220V/50A mains wasn't capable of melting everything. I wish it were a sealed sub because it would underscore my point. I wish real content had been used because it would underscore my point even more so. As I said, if Josh chooses to design a sealed sub system that is amplifier limited, who cares? I certainly do not and I can't see how that has anything to do with the subject. He sure as hell doesn't choose to test single drivers with an amplifier limited rig. The general rule in pro sound for centuries was "Always add +3dB of amplifier headroom". That's mostly because the systems are always pushed into compression and the headroom is used to compensate, but the rule also applies to HT subwoofer systems for transients. This practice requires thoughtful use and yields excellent results. Theory aside, I've posted those results for many, many years using accurate data from easily repeatable methodology.
  10. Josh, I really don't have the time to rehash a decade of posting on this subject, so I won't. Your own tests suggest that what you say in the bolded paragraph is inaccurate. You are free to design any system as you see fit. Sorry, but I haven't seen any results from a system you've designed and built that agrees with what you've posted here.
  11. Sorry for the late reply. I've been busy with things that matter. You fellas crack me up with the whole "...I thought you were joking, you prat" sort of shit. First, please tell me you aren't going to bring up that silly and wanton destruction of drivers at the GTG to defend your position here? Of course, although we agree you can't name enough to occupy all of the fingers on one hand, there exist a few scenes with sine wave content in soundtracks that are demanding on a system that has no electronic protection against such content, which is why anyone with half a brain should always ease into a new soundtrack with ANY system, regardless of test results data or published specifications... especially when someone with half a brain is yelling to the guy with the remote in his hand to "BACK OFF", three drivers into the childishly silly demo. Sorry, but... irrelevant to my point. You've already made that point by citing your sine wave testing methodology and how it relates to excursion and power drain. An excerpt from an article from the 80s: What did the ^^ experiment have to do with sine waves? Nothing, of course. How many watts would it have taken to cook and/or unload the drivers being used in the experiment with a sine wave input? Not at all relevant to the discussion. You're suggesting, and have suggested the same in the past, that the max excursion reached at 10 Hz with sine wave input in your all but irrelevant to playback of soundtrack content ground plane tests is the maximum a driver in a box can handle. If I'm reading you incorrectly on this point, please help me out with this. But then, you devote a paragraph to emphasize my point, which is that real content is dynamic, more specifically, transient in nature and extremely wide bandwidth (in the case of a subwoofer, the transients are full bandwidth) and thus requires much more amplifier output capability than a 10 Hz sine wave will require to drive the system to max excursion. No, it's not as difficult on a driver from a standpoint of excursion. Yes, of course it's more demanding on the amplifier... which is my point. Instead of that preachy paragraph, can you tell us, in the case of the hulk scene being cited, exactly how much more voltage is required? (because I obviously disagree with your contention that "no real power is required" to reproduce transients in the subwoofer band). How much 10 Hz sine wave can the 2 x HST-15s take at 2M, GP in 5 cubes? I dunno, that's your milieu and for you to answer and ruminate over. How much power did it take to reproduce the Hulk punch effect in a room where the effect is transient in nature and full bandwidth? 9,000 watts. 8,915 watts to be exact. Using your metric, the amplifier would be rated at around 3,000 watts and thus there would be no way to even approach accurate reproduction of the effect without amplifier protection/distress stopping the experiment or a severely reduced playback level that would under-utilize the drivers capabilities. I think that's commonly referred to as an "amplifier-limited" system.
  12. You need to own stock to have a bias? Well, there goes my bias for Heinz Ketchup. Try to stow the hard guy shit until we get through this? You brought up the suggestion, not me. We've been through this before. Your amplifier is only viable when run into 2 ohms nominal, stereo. It cannot be bridged and into 4 ohms or 8 ohms nominal loads it doesn't stand a chance against a bridged A-14K. Therefore, I'm restricted to using D4 VCs and a wiring scheme that ends up at 2 ohms per stack. Although you believe that that scheme is perfectly acceptable, I do not agree. OTOH, if you will send me one and accept full responsibility for its well being, I will oblige and wire a Raptor System III to a dual 2 ohm scheme and be happy to do it. It will likely measure a nominal Re of 1.8 per channel.
  13. OK, Josh, I'll have to call you on this one because one of us just doesn't seem to get how dynamic source works and I need to get to the bottom of it. Firstly, yes, long term sine waves and/or sine sweeps can ruin a driver... any driver. Duh. Let's move on. At Brandon's previous GTG, we ran the SP2-8000, one channel per VC of a single HS24. The driver was in the same box you tested it in. So, using the dictates in your post, the max the amp was giving was 1000 watts per channel, more likely less than that because the content included well below 20-25 Hz and the driver did not indicate being at X-Mech to anyone in attendance including myself, who had his head literally in the cone. Seriously? I'll post this again, to open the discussion. The Hulk punch scene. Let's assume the 10 Hz portion of the content is 3,000 watts, or, enough to drive the HST-15s to maximum excursion. (It's impossible to segregate the 10 Hz portion of the effect but driver excursion in the known box volume is a pretty good yardstick) So, the other 3-1/2 octaves of content in the effect require zero watts? Paul's DMM isn't accurate to a fraction of a volt? The A-9K really doesn't output 9,000 watts?
  14. After wondering WTF I'm talking about, you said this: Well, sorry, it should be obvious to even a casual observer of Josh's test results that it takes every bit of a K-20 to post the same results. It's not my intention to post recipes on how to cook an HS-24, or any other driver. It's patronizing condescension to infer I ever did. I've routinely coupled more than 1500W with far less power handling capable drivers, many, many times. I have NEVER "smoked" a VC. Then, there's this: Yeah, silliness. Let's see, 400V? @ 50 Hz into 5 ohms = 32,000 watts, and the amp ran out of gas. Was the VC "Smoked, period"? How silly is that? Let's see, what would the result have been if Josh used 1500W? Around 115dB? That changes the result a bit. Is Dave Gage insane to couple the driver with a 4,000 watts, continuous capable amp, or do you approve of 6dB less headroom than your smoked level? The condescension I suffer is from people like yourself who seem to think they understand every aspect of a sealed subwoofer system to such an extent that what I post on the subject is error wrapped in silliness and sarcasm. If you prefer to wonder out loud WTF I'm talking about through the silliness of my SI lovefest posts, expect some condescension.
  15. Yes, power in the wrong hands is not good. That goes without saying. Hopefully, we don't have to address the obvious from here out? The point of my post was in reaction to the "OMFG!!!! YOU HAVE 8 OF THOSE??? YOU MANIAC, UR HOUSE WILL COLLAPSE!!! If you buy 8 HS-24 and power them with a single Behringer amplifier, you might gain 6dB over a single driver, if any gain is measured. Regarding cooking the VC with 1500W, or whatever it was you were trying to say, what am I missing in the following graphic that shows 33,000 watts being utilized in half of bandwidth of the CEA 2010 regimen on a single HS-24? IOW, Josh dumped the entire amplifier into the driver and it still was an amp-limited result. If he intends to mean that the result is misleading, there should be some disclaimer o that effect with corrected max SPL numbers. Real input source requires a LOT of power. Let me repeat... We dumped 9,000 watts into 2 HST-15s during playback of a single movie soundtrack clip... repeatedly. First, to measure the amplifier output, second, to measure the drivers excursion and third, to measure the accuracy in the in-room reproduction. At no point was the VC in danger. We graphed the SpecLab comparison result, the O-scope result, the amp measured voltage and current output results and measured excursion result with videos.
  16. The 'everything-I-buy-is-better' bias. That's an observation from our forum discussions, FWIW. No dis intended, just an observation. I don't recall anyone ever dismissing the SpeakerPower products in any way. If that happened, I'm just not aware of it. What bothered me was Seaton's comments when it was first mentioned in Brandon's GTG thread. He dismissed the problem as line sag. Well, those of us who were there know that wasn't probable and if it were, do the amps come with a noted mains requirement? Blah, blah, blah. I thought it was water under the bridge, but a still unresolved situation. Efficiency is a good thing. But, the difference between 60% and 90% is 50%. That translates to fan noise and nothing else. I've run my amplifiers for over 5 years in their intended app. Can you cite anyone who employs a 10dB L/T and runs a SP amp to its limits for that long? That's really what determines if efficiency was sufficient to forgo overkill cooling methods in the intended app. Otherwise, what matters is performance. Size is the same. Weight is irrelevant.
  17. I never heard the projector fan during our actual movie watching at your place. It certainly didn't affect the experience for me at all. BTW, I'll say it again, Adam's HT is superb. Huge screen, great PQ, clean surrounds and thunderous, full bandwidth bass. Paul and I fussed over the amplifier fan noise issue years ago and we lost several amplifiers in the process to rapid increases in transistor heat. Recently, as I mentioned earlier, we tested 2 amps with near-silent fans that are supposed to ramp up with increase in heat. They did ramp up alright, but the damage was already done. This would mean that more $$ needs to be poured into components but then the market shrinks fast, so the typical solution is to say the amp is not 2 ohm stable. Of all the possible solutions, we like the larger case, larger, slower fan solution. Problem there is obvious... the amp would have to be unrestricted from above. No stacking on top. Honestly, since then we just ignore fan noise. If it's a problem that the end user can't solve by isolation, we then conclude we have the wrong end user and suggest he move on to a different solution than what we offer.
  18. You make too much of the GTG amp thing. It lingers because no solution to the problem was ever investigated or properly proposed by those with a vested interest. Fork one over, I'll be glad to accommodate. Should be a 2dB difference in transient reproduction capability. I doubt there will be any surprises there. Your biases dictate your posts.
  19. Hmmm. So, you have data we don't? Post it, please? The HS-24 the plate amp drives is in a bit smaller box than your tests. Maybe it's time to test multiple drivers with various amplifiers. Well, we've been doing that for years, actually. The point was, however, seemingly lost. I must really be getting bad at simple explanation. If you use a single amp to run 4 vs one, you'll see a headroom increase of +6dB, no more, possibly less. THAT was the point.
  20. You misunderstood. I have nothing against horns, passive radiator, ported, bandpass or other. Just sayin' that big power is required. And, big power repeated is required to make the popular habit of adding 6dB per doubling applicable. Otherwise, not. 8x24" is a waste of drivers if the power isn't added with them.
  21. Due respect to the CEA fellas and Josh, but as I've said about 60 trillion times over the years, we use actual program source. Here's a CEA 2010 10 Hz shaped tone burst followed by the Hulk punch, no change in MVL/SW trim: The Hulk punch into dual HST-15s clocked 9,000 watts. The amp was an A-9K, so obviously was giving all the burst it had. Same result with a 5KW amp? 3KW? 1KW, or whatever the max CEA 10 Hz burst 2M GP test result takes? There's just no comparison in the input signals. The (movie soundtrack clip) result would have been better with a bigger amp. Wait... ain't you the guy who uses a bridged 6,000 watt amp to drive a ULF-Filtered horn???
  22. We can't get you off yer arse to upgrade from the Berry stuff, how the hell we gonna get you to pont up for a water-cooled amp?
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