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Crashpc ![]() Registered User ![]() Joined: 26 February 2008 Location: Czech Republic Status: Offline Points: 442 |
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The apparent power at many points across the frequency range will be lower at the same voltage at Master Audio driver. The higher Q driver (with other similar parameters) will draw more power, so has to have greater power handling figures. The sim doesn´t do good in this regard, as it´s purely voltage driven.
Everything about Xmax is just an estimate. I see Xmax 6,5mm on the P-Audio. http://www.paudiothailand.com/uploads/pdf/products/DATA%20SHEET%20EM18-LB600.pdf The very similarly looking B&C 18PS100 (to the Master Aduio) has 5,5mm. But it has thicker pole piece, so, it might behave better past this Xmax. I mean, offset the difference a little bit. Maybe. Running out of Xmax fast has nothing to do with Bl in this context. Also If the Qes is low, the BL, or rather normalized BL power ((Bl*Bl)/2) will be higher. Again, I can refer to 18PS100, which has both higher Bl and higher normalized Bl power. 22,5 and 95,52 of the B&C against 21,29 and 78,15 of the P.Audio. Yet the B&C has lower Xmax. So it all really hangs on two simple facts - real Xmax of the unknown driver, and long term reliablity. We have no idea.... Edited by Crashpc - 12 August 2017 at 7:59pm |
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Nikon and Canon people should not be married to each other. Why did you let this happen?
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Hemisphere ![]() Old Croc ![]() Joined: 21 April 2008 Status: Offline Points: 2272 |
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I think you're misunderstanding what I mean when I say 'running out of xmax'. I mean, the excursion levels increase faster for each watt of input. So one might reach 5mm with 100w while the other needs 300w to reach 5mm. There is absolutely a correlation between this and BL. I've updated my previous post to include some interesting pseudoscience, by the way.
I've normalised all xmax ratings to the somewhat over-inflated methodology used by some. It's easier that way. I'm pretty certain Eminence and Beyma both use it, although they may divide the added gap depth by 4. P Audio definitely doesn't. Their 6.5 becomes 9.75, or 8.95 if you divide the gap depth by 4. In my sims I guessed the BL of the MA driver at 20. In reality there's a good chance it's less than that, but 20 is probably a fair guess. The IMF driver is 20, the budget Beyma 18 is 18.2, the Sigma is 22, and the other P Audio driver we simulated is 21.29 If I set it to 15 then it's +1.4mm excursion at 200w.
Edited by Hemisphere - 12 August 2017 at 8:35pm |
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Crashpc ![]() Registered User ![]() Joined: 26 February 2008 Location: Czech Republic Status: Offline Points: 442 |
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Okay. At least now I understand, but I don´t really agree. On the end of the day, for bass, the ultimate value comes from displacement volume and motor force, if all else being equal (the box, the woofer size). If one woofer goes to Xmax with less watts, it can easily mean, that it has more efficiency. That´s not bad thing at all. Sure, there is a correlation between this and BL.
After seeing your edited post, it still leaves too great chunk of facts unsolved/unconfirmed. We don´t have idea about amount of distortion, and the MasterAudio driver image is smaller, aand it comes from poorer angle, so the excursion must look smaller. Again, it proves nothing. I am well aware of that track, and of others. Used "Curtain shaker" for mine: https://www.youtube.com/watch?v=swo_RCMP_1I You really cannot set BL as you wish. Although I didn´t like it really, it came as 26 to me when I "let count the rest from base parameters". Again, I see your points, but no proof... Edited by Crashpc - 12 August 2017 at 9:19pm |
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Nikon and Canon people should not be married to each other. Why did you let this happen?
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Hemisphere ![]() Old Croc ![]() Joined: 21 April 2008 Status: Offline Points: 2272 |
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Well we know one thing for certain - the xmax of the IMF-18HPW is 2mm, or 5.33mm by optimistic ratings. That is a fact. Another thing we know for pretty damn certain is that when people make YouTube videos where the main purpose is to show off how far their woofers can move, they don't take a great deal of care for measuring distortion levels, especially when they have cheap woofers that can't move so far, they'll want to push them as hard as possible to look impressive. It's not a scientific test, they're trying to show off - I've done the same before, it's too hard to resist, and you can always find some tracks where it even sounds great turned up way past xmax, so why not? We can also say for sure by looking at the physical distance of excursion in the P Audio video, that is more than 10.6mm, it's more like 18mm, so that woofer is going way past xmax and right up to the edge of it's physical limits. Is the bloke with the Master Audio woofer turning theirs up to the same extent? Maybe they aren't, but probably they are, and if they're not then they're at least close to it. The woofer pictures I showed aren't different sizes and I could redo it more carefully if that would help, but I was only looking for a rule of thumb. From the comparisons I've made it visually appears that they have approximately the same excursion. That would mean that Master Audio driver has 5.33mm xmax. I understand the potential issues you mentioned which is why I rated it at 5.5-7.5mm. You also don't consider that perhaps the P Audio user is running theirs more conservatively than the Master Audio user, so maybe the MA driver is 4.5mm xmax! But I'm positive it's 5.5-7.5, and that makes it at minimum 2.25mm less excursion than the P Audio we measured earlier. Like you said, and I agree, we can't know these details from the limited available evidence, but all we're trying to do is determine which represents a better value for money. The P Audio driver at 124 pounds or the Master Audio driver at 129. For me this is solid enough 'data' to at least make that call. Can't see that MA driver being 26 BL. Budget driver = Low BL is almost universally true. Of the 18" woofers in BlueAran up to the 195 pound price point, the only woofers with 22.5 BL and over are the Oberton 18B500 with 24 at 168 pounds, and the B&C 18PS100 you mentioned with 22.5 at 194 pounds. Most of the rest are between 18 and 20. I think you're expecting miracles from this driver but the likelihood of one remaining uncertain specification being miraculous in the face of the rest plus the retail price, the ethos of the manufacturer/rebadger and the relative quality of their other products stacks the odds massively against this being true, and unless it is true then the P Audio with 9.75mm xmax is the clear choice for less money. Another video of the 18 cone movement, looks to be a bit more professional, doesn't seem to be moving as far but no idea how loud its playing. But as an indication of the durability of the LSN line in general, here's apparently what it takes to blow the 12" version: Can't have been going more than half a cm peak to peak when it died. The description from the video is worth a read:
That's the same 12 inch we were talking about earlier btw, the one you thought looked good @$115. I think I'll have to unqualify my original provision about 'junk'. I'm generally optimistic as yourself and like to assume the best before writing something off - the potential thrill of finding a diamond in the rough, and the fact that this does occasionally happen, makes it worth it, but that is unequivocal junk! Notice how everything written in this first hand experience was picked up on immediately by the other users here - The lack of xmax, the uselessly large voice coil, the misidentification in the description as a subwoofer, the unlikely power specification, and the lack of published specifications in general. You just waved all of these away like they probably weren't indicative of anything, even taken as a whole, just because the retailer selling them 'has a good reputation'. Maybe it's just that his customers don't know better.
Edited by Hemisphere - 12 August 2017 at 10:50pm |
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Hemisphere ![]() Old Croc ![]() Joined: 21 April 2008 Status: Offline Points: 2272 |
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To understand the actual science, by the way, you need to look at Mobiele Ennheid's post which you disregarded:
Mobiele really knows his stuff. I mean he understands the science behind the parameters and their relation with one another and performance in general. It's a big claim to say "no xmax", and it's hard to credit when so few modern speakers have less than 5mm xmax (by optimistic standards), but as it turns out it really had no xmax! 3mm xmech it looked like! Could have been 1mm mathematical xmax, 2mm with optimistic calculations. A lot of this stuff should really be intuitive though, even if you don't exactly understand the science. Big voice coils = heavy speaker. Small voice coil = light speaker. You can tell this just by examining the state of speakers on the market in the various categories. To look at it more scientifically (not that I'm very good at that, but I'll try) you need to look at the Qes, and the other available parameters, as these clearly instruct why the xmax must be low, at least it seems clear to Mr Ennheid, (who as I noted, knows that of which he speaks.) Low Qes means the magnet will need to be bigger because the electrical strength of the motor is low, so 5kg combined with a low Qes means you've got an underpowered magnet to start with, and that's not going to be happy moving a large moving mass. And a 4" voice coil usually means a large moving mass. Of courrse jut just because the voice coil is wide doesn't mean it's deep. If the driver is to have any sensitivity whatsoever, then it can't be deep at all. It's probably like, a couple of mm. Which is exactly what we see in the video! The 18" driver is a slightly different matter. It has a mass of 13.5kg, but again the Qes is very low. 0.39, with a 4" voice coil! The budget Beyma (SN118/N) is 0.65 Qes with a 3" coil, mms of 130 grams. Perhaps most damningly for the LSNN18, The ultra-budget P Audio (IMF-HP18W), which I showed the video excursion comparison of, has a 3" voice coil, 0.54 Qes, and an mms of 154g And that has an xmax of 2mm/5.33mm! The Eminence Sigma 18 has a lower Qes of 0.3, and a 3" voice coil, but it also has a very low mms of 130g, and a lot of that saving will come from the cone itself which is very light (and you can tell it's light because it's 99dB sensitive - it's also not treated at all, and not ribbed) It also has low xmax, just 6.1mm. Although the Qes is lower, if we translate the 3" voice coil to a 4" and adjust the Qes to compensate, it would have 0.4 Qes - a tad over the 0.39 of the Master Audio. So it's not looking good for the excursion capacity of the LSN18! When we take into account the visibly greater weight of it's cone (coated and ribbed like the IMF, so it could be 175g mms), even with it's somewhat larger magnet (13.5kg total weight versus 11.1kg for the Sigma, although the Sigma looks to have a lighter frame so could be adjusted to 12kg), it's unlikely that it will exceed the 6.1mm excursion capacity of the Sigma Pro 18 - it might even be a touch lower - and that matches up with what we see from the video comparison. Like the Sigma, both the IMF and the LSN may have significant amounts of xmech, hence the impressive looking excursion videos - The Sigma Pro can move 36mm peak to peak before damage.
Edited by Hemisphere - 13 August 2017 at 3:07am |
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Crashpc ![]() Registered User ![]() Joined: 26 February 2008 Location: Czech Republic Status: Offline Points: 442 |
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That´s a lot of funny text. I really do appreciate your guesswork, but as we don´t know many facts, and many facts migh be wrong, it´s of no use really.
For the previous post before the last one you made, I´ll make it short: I insist on that your comparison is wrong, because of different object sizes and angles. I don´t expect miracles, I just don´t buy poor guestimations. I´ve seen the youtube guy before. Might, or might not be true - You can actually find B&C drivers with very similar problem on youtube. Namely 12PS100, 12NW100, and some larger pieces. That doesn´t prove B&C speakers are trash, right? The same way, it doesn´t prove much about MasterAudio. You miss one BIG thing. The weight is propably wrong. The manufacturer states 125oz magnet on all three drivers (12",15",18"). Yet, if you compare weights, it´s completely different. Then you would imply that the 18" basket and cone weighs 9,5kg? :-D As I said, poor guesswork. For the last post: Except for grabbing on possibly wrong data about the weight I mentioned few lines before, it´s not even funny to put anybody as an authority, and use it as a technical high ground. It doesn´t work like that, and without facts or an evidence, connected with implying that I don´t understand the science, is very lame attempt of bullying. Really.
Sure. No denial. But I call the weight parametr unsure fact in it´s value. It´s possibly all wrong based on the finding, that all models share the same magnet size, weight, and the same motor assy.
Bhaha yes. And B&C 18PS100 has 4" VC, Qes is 0,41 - fairly close, and it weighs 10,5kg, and has Xmax of 5,5/8mm/8,25mm/9,1mm depending on interpretation. How is that even possible? :-D :-D :-D Based on revealed stuff, I cannot take your claim of "not looking good" as a driving factor for buying decision really, because it´s free of facts. But you bring me at the edge of buying some of these to just find out. Edited by Crashpc - 13 August 2017 at 8:42am |
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Nikon and Canon people should not be married to each other. Why did you let this happen?
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Hemisphere ![]() Old Croc ![]() Joined: 21 April 2008 Status: Offline Points: 2272 |
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All I'm doing is building up data points that are either concretely knowable or partially knowable, and trying to draw an increasingly solid conclusion from that. All you're doing is wall to wall denial and obstinate refusal to see anything beside your initial position of 'we can't possibly know anything! It could be a great driver! None of the specs are published so there's a chance they'll all be fantastic! 12" driver for $115? Looks good to me! It's got a cast alu frame so it must be better than the Fanes' etc. The B&C 12PS100 indeed shares some circumstantial characteristics with the LSN12 (the large voice coil ie) - it's also evidently the design which Master Audio based their LSN12 on - visually everything is identical - the cone, magnet, voicecoil, dustcap etc. But that is the entire Master Audio business model that I pointed out before. They make a speaker (or rather, they apply their badge to a generic clone speaker - as others have mentioned they don't make anything themselves) that looks like another speaker but doesn't perform like it. This is a big problem in budget woofer design, because an expensive woofer looks the way it does because of the way it performs. You just can't design a speaker driver based on how it looks and hope it will perform well, and certainly not if you want to design a cheap speaker that looks like an expensive speaker. That's a recipe for disaster as the LSN12 aptly demonstrates. It's like, you know the people who come to these boards and say "I've got a 10" woofer and I want to build a Superscoop! If I scale the dimensions down will it work?" That's basically what these drivers are like. The B&C models you've linked to all have one thing in common - they extensively employ expensive optimisations, in the design and manufacturing process and in the components used, which cheaper drivers don't use. Do you think if you look inside these LSN drivers they'll have fibreglass voicecoil formers, inside/outside edge winding? Of course we can't be sure, but we can make an educated guess from the price and apparent performance, that they will have cut corners wherever they can get away with it. You're really scraping the barrel and beginning to sound like a Master Audio salesman to say 'well we can't trust that the weight specification is correct! They're probably heavier and more powerful really!'
As to why B&Cs PS100 line seems to perform better per kg of weight, the basic answer is they're just higher quality parts. They take advantage of a whole host of optimisations which are expensive to impliment in a design - inside/outside voicecoil winding for extra heat dissipation, fibreglass voicecoil former for lower Mms. In addition to those optimisations and the well established craftsmanship and expertise of B&C (which extends not just to quality but to their ability to do more with less, same as a good box designer can squeeze more dB of efficiency through design optimisations), the 12PS100 model you reference has 8.8kg of weight, again almost double the weight of the LSN12, and a huge proportion of that extra weight is going towards magnet strength and heat dissipation. It's also $238 for a 12" ferrite driver! That's bloody expensive even for B&C, but you can see where the money is going. That's what allows it to have a high xmax with such a large voice coil in a small driver. Loads of weight, magnet strength, highest quality components and design optimisations up the wazoo. The LSN12 has none of those things and so it craps out at 2mm instead of 8mm. The 4 inch voice coil was an elementary design error fuelled by the desire to look exactly like the popular industry standard 12PS100, in order to trick people into buying it, and it seems like it's worked on you! Same as they did with the Behringer mixer knockoffs and the Mackie subwoofer knockoffs that I linked to earlier. The same optimisations and high quality components used in the 12PS100 also account for the unexpectedly high performance found in the 18PS100. All the comparisons I made were deliberately with budget woofers in the same league as the LSN18. Your comparison is apples and oranges. Edit: By the way, the reason I 'put Mobiele Ennheid' as an authority is because I've read his posts extensively over the years and plenty of the documentation of his audio design work, so while I don't have a solid grasp of the science myself, I figured if I assume the truth of his statement as a basis for my reasoning I'll probably reach a fair conclusion.. seems to have worked well enough. As a small followup relating to what I was saying about quality components, let's go back to a couple of the other drivers we looked at - the P Audio IMF-HP18W from the excursion comparison videos, which imo is the closest comparable woofer on the market to the LSN18 From the spec sheet: Bobbin wound voice coil geometry Aluminium voice coil former And then the other budget P Audio woofer which I reckon represents the best value for money, the EM18-LB600: "Precision round wire inside/outside coil design" (that's not a typo for 'precision wound' btw - rather specially engineered perfectly geometrically round wire, which I suppose is optimal versus regular copper wire, and it's that sort of degree of optimisation that will be applied throughout the design process by a high end manufacturer) "Former material: Glass fibre" They're both about 10kg in weight, but the EM18-LB600 has literally double the xmax, so you can see these little details - which are definitely considerable added expenses - can make all the differece. Over the course of an entire design from conceptualisation through to actualisation, there are endless opportunities to cut corners like that, and when that happens the results end up directly reflected in the specifications. That's why crappy drivers don't publish their specifications. For what other possible reason would they not publish them? I spoke earlier about the general false economy of buying budget woofers, and that you should just buy one high quality woofer unless you're only building one cabinet. Even if you were planning on running one bass bin per side, you'll be much better off running your bass in mono to begin with. Here's what I recommend: For only 15% more than the price of a pair of LSN18's, you've got a top of the line ferrite bass driver with 16mm xmax and 1200w RMS power handling (again normalising to optimistic standards - 12mm conservative rating). It'll move at least as much air as those two drivers (and close to as much as 3 of them), and it'll get at least as loud as two of them if not three of them as well. As previously mentioned, by choosing a single quality driver you halve your outlay on cabinet construction costs, and ease your workload considerably on moving your system around. It'll also work perfectly in all sorts of extremely demanding complex enclosure designs, so that's a plus.
Edited by Hemisphere - 13 August 2017 at 1:59pm |
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Crashpc ![]() Registered User ![]() Joined: 26 February 2008 Location: Czech Republic Status: Offline Points: 442 |
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Of course. We have freedom of speech. One doesn´t even need to see the speaker nor its parameters to make a judgement. But what value does it have for us, if it is poor? I do the same with "data points", and I have different outcome. For example I know, that all three LSN versions have the same magnet. Especially including WEIGHT. Solid conclusion from wrong data (I.E. weight and Xmax) cannot be made then. Do you truly believe, that chinese make of reverse engineered original - even with the same parameters, would have the same price? I don´t. Italians are quite expensive, Most PA audio sellers selling these brands also have great margins on top of that. Around 80-100% for shop price is not abnormal. So the expectation of chinese copy being cheaper is absolutely normal and healhy.
I see. I just cannot agree on the evidence you brought up, and on so called facts. I explained why is that, and you also denied that. But instead of bringing better facts or discussing particular aspects of the speaker more, you bring an authority claims, accusations of doing this and that, and false assumptions. I don´t play this game. Speaker of half price of the original isn´t really expected to perform the same, soooo, we´re just repeating ourselves. Comparison with the superscooper is quite drifferent. Because no manufacturer could make the smaller version work as expected by those "Iwanters". From the parameters, it´s quite obvious, that at least 15" and 18" versions propably have Al coil formers. Not sure about 12". That´s still not a problem, as it´s quite normal to build speakers in this price like that. No matter if Hi-Fi, Car audio, or PA. If you do absolutely expect from half price copy the same performance, I might get disappointed.
Now you´re making yourself the decisive factor on what´s BS and what´s not. That´s really dismal. Before, it has been said, that with the weight, things are not possible. Now these are possible. How vague do you want to go in this discussion? I mean really. Just guessing, imposing, accusing. For over 300Pound, I can have B&C 18SW115. I actually had it for 266 in mint condition. And for 400, I had my 21DS115, which both have larger coils, and are generally bigger beasts. But that is complete irrelevant to someone who wants cheap driver for around 100Pound... Edited by Crashpc - 13 August 2017 at 3:44pm |
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Nikon and Canon people should not be married to each other. Why did you let this happen?
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Hemisphere ![]() Old Croc ![]() Joined: 21 April 2008 Status: Offline Points: 2272 |
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![]() Three models here, all 125 litre boxes tuned to 41Hz. The green line is the BMS driver with 2500 Watts of input. (excursion 16mm) The blue line is 3x LSN18 drivers, each in 125 litre boxes, with 300w input each (excursion 6.6mm), the orange line is 3x EM18-LB600, each in a 125 litre box, with 900w input each (excursion 9.75mm) The EM18 is cheaper than the LNS18 and outperforms it by as much as 7.7dB (and by at least 3dB across the entire frequency range). I agree it's typical for a budget woofer to use cheaper components for the voice coil and former - the point about the EM18 is that it has a budget price but it uses high quality components.
As I pointed out earlier, P Audio (as far as I can tell from my research) literally reverse engineers (and redesigns from the ground up) the designs of high end manufacturers and sells them at a knock down price. That's why they're not afraid to publish specifications, because they're willing to stand by the quality of their work, which while it may not be as good as the real deal, is at least significantly cheaper and a fair approximation. They also produce a fair few of their own designs, I've just noticed a few drivers in the past that are uncannily similar to another manufacturer's product, and I think I recall Rog saying ages ago that the SD18 was a clone of another driver. You're working to the assumption that Master Audio follows the same or similar methodology. They evidently do not.
Edited by Hemisphere - 13 August 2017 at 4:20pm |
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Crashpc ![]() Registered User ![]() Joined: 26 February 2008 Location: Czech Republic Status: Offline Points: 442 |
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Only for multiple drivers of the cheap one. I can agree on that one. That´s why I got 21DS115 instead of two ordinary 18"s. For one piece, there is nothing in half price. The P Audio EM18-LB600 haven´t been proven as better yet. Anyhow. Lol, So you feed 800W driver by 300W, and then 600W driver by 900W, and you wonder why you end up in so skewed simulation outcome. That´s absolutely ridiculous. Wow. Just Wow. And that´s not counting the amp price - 900W against 2500 and 2700W respectively. Your proposals make no sense this way. I´m done. Thank you. Edited by Crashpc - 13 August 2017 at 4:24pm |
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Nikon and Canon people should not be married to each other. Why did you let this happen?
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Hemisphere ![]() Old Croc ![]() Joined: 21 April 2008 Status: Offline Points: 2272 |
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The EM18-LB600 is 600w RMS, 1200w program. It will happily run on 900w (of well managed peaks) all day all night. Although perhaps not with your 4dB dynamic range music. Have you got a link to that? 900w is when the excursion limits of the EM18 run out, 300w is when the excursion limits of the LSN18 run out - to the best of my reckoning as there's still a degree of guesswork going into the LSN18 model, but it won't be substantially better than that, and it might be worse. A Behringer iNuke3000 will power any of these setups for 225 Euros. You could still power 3x EM18 with a 900w amp and it would outperform the 3x LSN18 by 0-3dB from 50Hz and up, but having the opportunity to expand the headroom by another 5dB later down the line is worth the extra investment. For people on ultra-budget, if you're looking at jusst one cabinet you're still talking about the difference between 120dB peak and 127.5dB peak with a 900w amp, so you would need a pair of LSN18 to match the output of 1x EM18, if you're willing go buy a 900w amp instead of 300w.. No problem getting a 900w amp for less than the price of an LSN18 and then you've got one less rubbish bass bin to carry around and work out what to do with later when you upgrade and you find it has no resale value.
Edited by Hemisphere - 13 August 2017 at 4:39pm |
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Crashpc ![]() Registered User ![]() Joined: 26 February 2008 Location: Czech Republic Status: Offline Points: 442 |
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NO. :-D
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Nikon and Canon people should not be married to each other. Why did you let this happen?
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