Bill Fitzmaurice

[quote name='JPJ' post='1224066' date='May 8 2011, 07:45 AM']Thanks for that, more or less confirmed my thoughts/fears about the neos so it looks like Delta's it is.[/quote]Model them both in WinISD Alpha Pro, look at the maximum SPL chart, and you'll see the Delta is an also-ran. Even the Basslite S2010 beats it, let alone the 2510.

[quote name='mcnach' post='1222580' date='May 6 2011, 03:49 PM']For gigs I often use a 410 with a 210 on top... I think I will try putting the 210 vertically next time and see what happens... would it make sense to align the speakers with the ones below... or not really bothered? [/quote] It may work better, hard to say, as the setup is already knackered by the horizontally placed drivers in the 410.

[quote name='gusthebass' post='1220622' date='May 5 2011, 04:05 AM']the line itself has to have the cross sectional area of the cone at the speaker end to avoid pressure changes[/quote]It doesn't, just as a reflex port does not have to have the area of the cone. [quote]with wadding you can slow the speed of sound[/quote] Not enough to make any difference. TLs are very misunderstood, and it doesn't help that there are many proponents of so-called mass loaded TLs that aren't TLs at all, they're tall skinny bass reflex cabs. It's all in the impedance. A TL has a single impedance peak, just like a sealed cab. If the cab has dual impedance peaks it's bass reflex. [quote]These may be great speakers but I wish people would be honest[/quote]Truth in advertising? What a novel concept.

[quote name='Phil Starr' post='1219241' date='May 3 2011, 04:57 PM']the easiest one to answer is your transmission line question. Although there are some technical controversies over these the whole point is to absorb the rear pressure and to stop it reflecting back to the speaker so you lose all the energy from the rear of the speaker and you have a decent mass of air in the line. Transmission lines promise lower resonance and smooth low end response with good transients but low efficiency.[/quote]Transmission lines are 1/4 wavelength resonant pipes. The 1/4 wavelength resonant frequency coming out of the terminus acts much like the port in a bass reflex. The line is stuffed with damping material to suppress the harmonics of the pipe frequency. The advantage to a TL is that below the pipe frequency response rolls off at 12dB/octave, like a sealed cab, rather than the 24dB/octave of a bass reflex, so you get sealed cab 'tightness' with reflex efficiency. The downside is that they need that 1/4 wavelength pipe, which is 5.7 feet for 50 Hz, 7 feet for 40Hz. They're just too big to be practical for electric bass.

[quote name='dan670844' post='1219010' date='May 3 2011, 02:08 PM']He its not a new idea WEM where doing it in the 60's and also had double angled cabs with 6 drivers in but they didn't catch on prob didnt look cool even though they where most def better than all the other crap and the time....................[/quote] The proof of concept can be seen in St.Pauls in London; the original installation was done in 1949. Acoustical engineers knew that was the right way to do multiple driver cabs for a decade prior to that. Needless to say Leo Fender and Jim Marshall were not acoustical engineers.

[quote name='Mr. Foxen' post='1218624' date='May 3 2011, 09:32 AM']Not sure that that is true, the woofer/mid ones are all about using tons of power to move loads of air in a small light package, and the small ones are for being able to take tons of power while still being small. The idea is they have a variety of sets of compromises in the line up.[/quote]+1. Long excursion drivers aren't higher in sensitivity than shorter excursion drivers; if anything they're less sensitive, as is the case with the 3015LF. The advantage to them is being able to utilize higher power amps. If you have a lower power amp they won't do you a bit of good, and you're better off using multiple less expensive cabs than one more expensive cab. The other advantage to high xmax drivers of the Kappalite mold is that they're state of the art with all of their specs, which means they work better in smaller cabs than most older driver models.

Every time you double the number of drivers you increase dB per watt sensitivity by 3dB, so yes, an 810 is more sensitive than a 210. You also completely alter the dispersion pattern with an 810 versus 210, especially if you have the 210 with the drivers horizontal. That's the usual alignment, and the worst way to place them. Accurate, honest SPL figures are simply not available. Most manufacturers couldn't show an SPL chart if they wanted to, because they don't have any. If you like the 810 sound but don't want to haul one use two 210s stacked placing the drivers on a vertical line. In most cases output will be adequate, and with no drivers horizontally placed dispersion will be better than an 810.

[quote name='icastle' post='1217784' date='May 2 2011, 12:24 PM']More detailed information is in the user manual available [url="http://www.ampeg.com/pdf/SVT450H.pdf"]here[/url].[/quote] Man Law #1: Never ask directions. Man Law #2: Never read manuals.

[quote name='OzzyGreg' post='1217343' date='May 2 2011, 06:18 AM']Strangely, these speakers from this Australian company (Etone, not Eton BTW) are highly respected from my observations over the past 20 years or more.[/quote]Unfortunately their data sheets, such as they are, look to be 20 years old. Look at the driver data sheets at Eminence and you find complete data, including SPL charts. They also have basic cab designs for most drivers, which show in-box response below 200 Hz, and list their displacement limited power and useful low frequency limits. If I was going with six tens I'd use Beta 10s or Basslite S2010. I wouldn't use six tens, but that's another discussion.

[quote name='0175westwood29' post='1216487' date='May 1 2011, 07:28 AM']im guessing theres some sort of mixer that goes between the amps and speaker? andy[/quote]No. You need to use two speakers. The one for dirt would best be a guitar ten or twelve.

[quote name='OzzyGreg' post='1216237' date='Apr 30 2011, 07:24 PM']Can anyone who is familiar with speaker design software PULEEEEZE run these figures and see what [b]you[/b] come up with? (I ended up with 65 litres for a twin driver box.) Greg[/quote] Your drivers are unsuited for electric bass, the Fs is too high, the Qts is too low, and since xmax is not listed there's no way of knowing their actual power limitations. And you should not be running the drivers placed horizontally, as that halves their dispersion. [quote]WinISD is useful because lots of people here have experience with it, so can point out how to use it.[/quote]It's as good a design tool as any. It also has the same limitations as any tool: you have to know how to use it, and how to interpret the results it gives you. In the OPs case my guess is that he correctly used his program to get the best result possible from the drivers he chose, the problem being he didn't choose the right driver. One uses software to design the right cab for a driver, but a far more important use for it is to make sure one chooses the right driver to begin with. IMO these drivers should not be marketed as electric bass drivers at all, but ultimately it comes down to the consumer having to determine driver suitability, rather than blindly trust the manufacturer.

[quote name='Arrakis' post='1215713' date='Apr 30 2011, 07:24 AM']Well im looking at getting some 12" Bass drivers and there are alot on the market. I was hoping that people could give their opinions and experiences on the differnet ones availbale on the market I havent been able to find any comparisons anywhere. Im kinda looking at Celestian Neo green labels or Eminence Delta or Deltalites.. whats the general consensis?[/quote] Choosing the right driver is literally a scientific endeavor, it's not a popularity contest. It begins by understanding what all of this means: [url="http://www.eminence.com/support/understanding-loudspeaker-data/"]http://www.eminence.com/support/understand...udspeaker-data/[/url]

[quote name='EddyGlee' post='1214178' date='Apr 28 2011, 03:50 PM']hey Bill .. the standard Delta-12 isn't even that good mate with only 1.6mm xmax![/quote]The 'Standard' Delta 12 no longer exists, except as eight year old NOS. The 12A is 8 ohms, B 16 ohms. If there was a C it would be 4 ohms, but there isn't. The LF models are technically subwoofer drivers, but quite obsolete really, having no more xmax than the current neo fullrange drivers. [quote]Is that for one or 4? 50 watts each in a 4x10 sounds enough.[/quote]Talking about the Delta 12 here. Rather than use four in a 4x12 I'd use two twelves that can handle 100 watts, for half the cab size and half the cost. When you get down to it the Beta 12 actually is better than the Delta. But the thermal rating of the Beta is 250w, the Delta 400w, and what sells is watts, not xmax. More than a few manufacturers have used Deltas when they shouldn't have based purely on the wattage ratings.

[quote name='EddyGlee' post='1214031' date='Apr 28 2011, 01:15 PM']ps.. Delta-12(8 ohm) For high power bass in sound reinforcement systems, bass guitar combos, club music systems and stage monitors. Eminence words not mine!! Chris[/quote]Eminence isn't above recommending drivers for more applications than they should. It's up to the consumer to check the specs and make sure of suitability. With only 2.4mm xmax I don't recommend it for bass unless it's for use with less than 50 watts. IMO 4mm is the minimum acceptable. 2.4mm is OK for what it should be used as, PA midbass, just like its smaller sibling.

[quote name='squire5' post='1213929' date='Apr 28 2011, 11:21 AM']Chris,the blurb on the Eminence website says that the Delta 10 is optimized for lead guitar[/quote]Not the Delta 10. BTW, where it works best is in a PA top, the low end is too thin for good results with bass.

[quote name='squire5' post='1213864' date='Apr 28 2011, 10:01 AM']These 2 drivers cost me a ton,so I'm relying on Eminences reputation to win through.[/quote] They shouldn't have, it's the least expensive driver they make. In any event should you have to do any more driver replacement first choose the appropriate model based on the driver T/S specs and how it models in your cab, not the recommendation of a retailer. If the retailer really knew what he was talking about he'd be designing drivers and speakers, not selling them.

[quote name='Arrakis' post='1210371' date='Apr 24 2011, 04:13 PM']I was thinking deltalites mainly for the weight issue Matamp 4x12s are heavy enough lol[/quote]Deltalite II 2512s need about two cubic feet[i] each[/i] for a good result. As already mentioned you can't just stick a bass driver in a guitar cab to make it a bass cab. Running the two with separate amps is the best option.

[quote name='waynepunkdude' post='1204103' date='Apr 18 2011, 03:30 PM']Anyone got any info on these, I know Neil Young uses one as a guitar cab, I've heard you can get them as a 6 X 15 + 4 X 12 but can't find any info. [/quote] I vaguely remember seeing one or two of them in the 70s. They look impressive as all get out, but the side by side mids and tweeters indicate that the designer had no acoustical engineering knowledge, and if looks alone didn't confirm that the resulting sound would leave no doubt.

[quote name='arthurhenry' post='1201118' date='Apr 15 2011, 03:05 PM']My 350 Watt Hartke head was putting out, I think about 240W into my 8ohm cab. The volume hardly ever went above 2, even on loud rock gigs. Last night I used my new Hartke LH500 for the first time. This puts out 350W into the same cab. The volume was on 6! Why?[/quote]Gain structure. Google it.

[quote name='Monckyman' post='1200382' date='Apr 15 2011, 05:30 AM']Clipping amps is not recommended by anyone I know in the industry,not P.A amps, not guitar amps,not bass amps. OVERDRIVING them is different, that`s pe-amp stuff, not OUTPUT amp.[/quote]Clipping and over-driving is exactly the same thing. As for clipping power amps, that's precisely what one does with cranked guitar amps, and damaged drivers do not ensue. The Martin document unfortunately is very flawed, as it doesn't distinguish between the potential for damaging tweeters (high frequency devices) with clipped waveforms versus woofers, which are completely and totally immune to damage. This document does make the distinction, though more than a few wags have managed to overlook the specific reference to [i]high frequency components[/i] and pronounce that 'clipping kills drivers', giving rise to the myth of underpowering: [url="http://www.jblpro.com/pub/technote/lowpower.pdf"]http://www.jblpro.com/pub/technote/lowpower.pdf[/url]

[quote name='alexclaber' post='1199073' date='Apr 14 2011, 04:41 AM']Read this: [url="http://barefacedbass.com/technical-information/mythbusters1.htm"]Amp mythbusting![/url] The Wizzy cabs have very low excursion limited power handling so you'll hear the increasing distortion (with clean sounds) well before thermal failure occurs. The risk from slap is causing such high excursion that the speaker doesn't just distort but completely runs out of travel, thus creasing the cone, buckling the voice coil or damaging the suspension. I think that's fairly unlikely to happen with that woofer but to be sure see if EA can tell you the ratio of Xlim to Xmax.[/quote]The xlim to xmax ratio is important, but a high one is by no means a guaranty of driver durability. When pushed past xmax additional power applied doesn't give more output, it just adds more heat. That tends to result in thermal power compression, which actually reduces output, which one may compensate for with more power, which means even more heat, and so on until the voice coil is toasted. And if the xmax is small this can happen well below the actual thermal rating of the coil. This is in fact the usual reason for blown guitar drivers, which have both very small xmax and high xlim to xmax ratios. It still boils down to if it sounds bad turn it down. If it sounds clean chances of damage are very slight.

[quote name='voxpop' post='1198655' date='Apr 13 2011, 03:31 PM']Yes its true, distortion is the thing that blows speakers.[/quote] Distortion doesn't blow speakers. High levels of distortion will be heard, however, if speakers are pushed hard enough where damage could occur. When that happens turn it down.

[quote name='Wooks79' post='1195233' date='Apr 10 2011, 06:49 PM']I was wondering about this and thought I would ask... Why is the ampeg 1x15 (Svt-15e or b-115e) only able to handle 200 watts at 8 ohms?[/quote] Because it's honestly rated. 9 out of 10 drivers with ratings higher than 200 watts can't actually make use of more than half their power rating before running out of excursion, and any more power added gets no additional output. Ampeg rates its drivers closer to the actual power the can make use of, not what it takes to cook the voice coils.

[quote name='Musicman20' post='1191248' date='Apr 6 2011, 06:15 PM']I understand that from an engineers point of view, but a customer? I can guarantee a large amount like ceramic loaded cabs...even if it's psychological. I cannot see them being phased out for a long time now this has happened.[/quote]Ceramic drivers in excess of ten pounds weight will eventually go away because of the price of oil, which determines the price of shipping. The neo situation should have been anticipated, but wasn't until too late. But it will be solved in relatively short order, as many neo deposits exist and the mines are already there, they just have to be re-opened and/or expanded. Investors are already scrambling to buy shares in neo mining, and the price of neo mining stocks has jumped.

[quote name='Musicman20' post='1190924' date='Apr 6 2011, 02:51 PM']I welcome new ceramic cabs.[/quote]The fact of the matter is that no significant R&D has been done with respect to new models of ceramic drivers, as they were in the process of being phased out. No new ones will come along now, as it takes over a year to bring new products to market, and by then the neo crisis will have passed.