Bill Fitzmaurice

[quote name='Musky' post='607645' date='Sep 24 2009, 08:09 AM']I don't think the 3012's are intended to be used in sealed cabs either.[/quote]+1. The EBP is over twice what a sealed cab wants. [url="http://www.eminence.com/resources/data.asp"]http://www.eminence.com/resources/data.asp[/url]

[quote name='Musicman20' post='605921' date='Sep 22 2009, 01:23 PM']Bill How do you rate the Bergantino Neo line...mainly the AE112? Thanks[/quote]I don't rate any lines. What I will say is that of all the dozens of bass reflex cabs loaded with a variation of the Eminence Deltalite II 2512 driver out there the AE112 is one of them.

[quote name='Linus27' post='605722' date='Sep 22 2009, 10:58 AM']600w ...should be enough.[/quote]The power output of an amp and power handling of a cab are not directly related to the sound levels you can get from them. Also, the thermal rating of the cab doesn't indicate how much power it can actually make use of. In the case of the GB 212 it might be able to take 300 watts before reaching the excursion limits of the drivers, and that's a generous estimate. So don't assume that you'll never need to run more than the 212; you're a lot better off assuming that at some point you will and plan accordingly.

[quote name='Linus27' post='604901' date='Sep 21 2009, 02:55 PM']Price is also an issue. I would look at the Genz Benz NEO 112 but they are about £500 and I believe still fairly chunky compared to other 1x12 cabs.[/quote]If you plan on using the 112 and 212 together for the big gigs the best result will come from another GB. Make sure it's twice the impedance of the 212. As to the cab size, low end output and cab size are directly related. If you compromise on the one you'll compromise on the other.

[quote name='TheBlueFalcon' post='603707' date='Sep 20 2009, 12:14 PM']If the E string on a 4-string bass is supposed to be tuned to 41.204Hz (even lower when "Low D" tuning is used or when using a 5-string bass) why are there so many cabs/combos that have 8, 10 and even 12 inch woofers that don't go below 45Hz?[/quote]Because the primary power bandwidth of electric bass starts at the 2nd harmonic, an octave up from the fundamental. The fundamental is there, but at less intensity than the harmonics until you get up around 100 Hz, where the fundamental begins to dominate. [quote]Can the difference be heard between one that "rolls off" and doesn't reproduce frequencies below 45Hz and one that is capable of reproducing the full frequency range[/quote]Yes, but the difference isn't all that much. OTOH many bass cabs, combos especially, have weak response below 100 Hz, and how they sound compared to a cab that runs flat to 50 Hz is pretty substantial. The main reason for bass cabs having a weak low end isn't the drivers, it's the cabinets, which tend to be far too small for the drivers within to operate optimally.

[quote name='nig' post='597487' date='Sep 13 2009, 11:50 AM']As far as I go back (30 years) the only info you ever needed was impedance and wattage and of course the hz frequencie for a bass speaker. please tell me more??? regards, Nig.[/quote]Here's a short list: [url="http://www.eminence.com/resources/data.asp"]http://www.eminence.com/resources/data.asp[/url]

[quote name='nig' post='597390' date='Sep 13 2009, 09:58 AM']Hi guys, has anyone a lead on where to get a replacement for my 8 ohm 12" gk neo, I usually use 2 1x12s with my RB 1001 but last nights gig was real tight on space so I used 1 cab and 10 mins from the end, smoke and then a frozen voice coil. boo hoo, so Ive mailed gk, checked out thomanns site but a uk speaker supplier would be cool, or maybe someone elses 300w 8 ohm 12" neo, thanks all.[/quote] You have to take the old driver out and identify exactly what it is in order to replace it. 300w 8ohm 12" is not sufficient information.

[quote name='chris_pokkuri' post='591084' date='Sep 5 2009, 06:15 PM']If playing with a full band (in my case 2 guitarists, loud drummer and myself) i'd say a minimum of 500w.[/quote] There are far too many variables in the equation to make a blanket statement of how much power is required. I run one channel of a Superfly into an 8 ohm 1x10 or 1x12, depending on my mood. That's only 160 watts, and I'm never wanting for more. My cabs aren't exactly off the shelf, but that's part and parcel of the variables involved. With the right cab you don't need much power, while with some (Basson, for example) you're hard pressed to ever have enough. And where output levels are concerned far more often than not power isn't the problem, inadequate/insufficient speakers to make full use of the power you have is.

[quote name='Mr. Foxen' post='590205' date='Sep 4 2009, 05:24 PM']Course, not everywhere has a PA, and much more often, the PA can't cope with bass. Not sure if America is like those places in Europe where you can get a grant and everywhere has great PA systems, but this idea that the PA will do it all seems to be fantasy in practice.[/quote] The situation here is that toilet gigs that pay crap expect you to supply your own PA, and if you don't have one you don't work. Which makes sense, if they had the money to pay well they'd have the money to install a PA. Good gigs pay well and provide PA. The better the gig, the better the PA. Either way, if you're going to sound good you need a good PA, either the house's or your own.

[quote name='KingPrawn' post='590120' date='Sep 4 2009, 03:17 PM']This may indeed sound very stupid, but it has never stopped me before. Is there a calculation for working out how loud your rig needs to be. eg style of music x venue X punters = Watts. Again i apologise for daft questions , but is is better to buy for example an ampeg head that is 450w or a lesser head that is 900w. Does the quality of build come into it?[/quote] No, for three reasons. First, watts and sound levels aren't directly related. Second, all else being equal twice the power only results in a 3dB increase in sound level, and that's just above the threshold of audibility. Third, and most important, your rig only needs to be loud enough to cover the stage. It's the job of the PA to cover the room. If you're trying to handle much more than a hundred seats or so without PA support you're probably going to sound bad and have stage levels loud enough to endanger your hearing.

[quote name='alexclaber' post='581432' date='Aug 26 2009, 09:39 AM']Wasn't it the famously hopeless BL years actually? Alex[/quote]Let's not forget about Lucas Lighting and the joys of positive grounding. In my college years one bought an MGB or Midget, or a Sprite, in the hopes that the coolness of the ride would get one laid. The time spent trying to keep the damn things running was so all encompassing that any all other extracurricular activities, including a decent nights sleep, were relegated secondary status at best.

[quote name='karlfer' post='579983' date='Aug 25 2009, 06:02 AM']Anybody using any of the Chinese stuff?[/quote]There's precious little that's not sourced from Asia, if not as a finished good then as the components within. BTW, neither quality nor lack of it is defined by national origin. I remember when, if you considered a certain brand of automobile, you were encouraged to buy them in pairs, giving you one to drive whilst the other was in the shop. The brand was Jaguar.

[quote name='alexclaber' post='581114' date='Aug 26 2009, 05:48 AM']"High-quality" being the critical phrase! Alex[/quote]That depends on your definition of high quality, which IMO isn't far off from high fidelity. As with a hi-fi speaker a good PA speaker puts out pretty much the same sound as the source, with minimal coloration of its own. At the opposite end of the spectrum are guitar cabs, which are as colored as it gets, the tone being virtuallly defined by the speaker. Some electric bass cabs are so highly colored that it doesn't matter what you have for an instrument or amp, everything sounds pretty much the same through them. Some, though very few, electric bass cabs are uncolored, allowing the tone of the instrument and amp to come through. Most lie somewhere in between. For the most part the degree of coloration is inversely proportion to the cab's level of engineering and cost, though some very expensive cabs are highly colored and poorly engineered, which IMO makes them low quality irrespective of their price. If you prefer a cab that's highly colored there's certainly nothing wrong with that, beauty does lie in the ears of the beholder. My preference is for cabs that allow me to get the tone that I want, not just that tone that they're capable of delivering. For those with a similar bent trying PA cabs to see how they work for them is a more than worthwhile exercise.

[quote name='warwickhunt' post='580791' date='Aug 25 2009, 06:13 PM']why, at less than £100 a piece, wouldn't they make stonking bass cabs and why don't more people utilise used PA cabs as bass cabs?[/quote]Because the average bass player is under the wrongful assumption that 'electric bass' cabs are somehow better suited to the needs of electric bass. The very highest frequencies aside the needs of high quality PA and high quality bass are the same.

[quote name='escholl' post='575906' date='Aug 20 2009, 01:34 PM']as mentioned, it's just part of the tweeter protection and is nothing to worry about. you amp is fine. :][/quote] Yes it is the tweeter lamp lighting up and yes, you should be concerned, as that lamp only lights up when there's excess high frequency input to the tweeter that could harm it, or the lamp, or both. I wouldn't panic, but I'd refrain from doing whatever you were doing that made it so angry.

[quote name='alexclaber' post='569164' date='Aug 14 2009, 10:54 AM']The problem is that anyone with experience of those other drivers won't have experience of them in the Jack 12, and that's the only kind of experience that counts. Based on my knowledge of Bill's other mid-horn designs you'll need a rising response in the midrange to compensate for the lowpass nature of the horn. Alex[/quote]There's an open thread on my forum right now from someone in the UK who built OTop 12s using drivers that were not recommended, but because someone on another forum said they were OK he used them anyway. The cabs don't work right. I have a support forum specifically to help builders avoid such mistakes. Ignore it at your own peril.

[quote name='alexclaber' post='568893' date='Aug 14 2009, 07:14 AM']Well if you will insist on using such a spectacularly wimpy amp... Alex[/quote]Between the infirmities of age and my Scot blood that won't allow me to pay more than I have to the Superfly meets my requirements for weight and price. Since my speakers have the requisite sensitivity to give me the output I want 'tis hardly problematic. But I'm hardly the only person with less than a kilowatt at my disposal, and this does bring up a valid point about long excursion high power single woofer cabs: while they may have the potential to have output equal to larger multiple woofer cabs, they'll only do so with adequate power. Potential purchasers of said speakers who don't have better than 200 watts or so may find that, unless they want to get a new amp, they may be better off with the higher sensitivity offered by dual woofer cabs.

[quote name='alexclaber' post='568439' date='Aug 13 2009, 04:40 PM']So Bill's previous assertion that a Jack 12 will beat a fEarful 12/6 or 15/6 hands down is hyperbole. If you have the power the fEarfuls are more than competitive. Alex[/quote]'If' being the operative word. I run a Superfly myself, and with it I have to run two cabs the equivalent of fEarful 12/6 (3012 HO/ Celestion NTR06-1705B loaded) to deliver as much clean output as one 2512 loaded J112. [quote]Although a midrange horn does increase the midrange sensitivity and improve the off-axis response, it adds colouration which may not be desired and increases cab size for equal LF sensitivity. It also has no benefit for excursion limited power handling which is the usual limiting factor in bass cab output.[/quote] The acoustic loading of even a short horn does increase excursion limited power, and low frequency sensitivity as well. I tested my J112 side by side with a reflex loaded box of exactly the same size, loaded with the same driver. The J112 beat the reflex across the board save around 1kHz. You do have to give up something somewhere to gain it somewhere else.

Be it used or new buy the best quality head you can afford, so as not to outgrow it in short order. Probably the most versatile cab configuration is the 2x10. One will cover the smaller gigs, two just about anything. 8 ohm 2x10 is the best option, so that you may run two with almost any amp, and as many as four with some.

[quote name='deksawyer' post='567997' date='Aug 13 2009, 09:30 AM']I have a pair of B&C 12HPL64 12" Neo drivers, 4 ohm though. Yours for £150/pair inc. shipping. Same as these but 4 ohm; [url="http://www.bluearan.co.uk/index.php?id=BAC12HPL64&browsemode=manufacturer"]http://www.bluearan.co.uk/index.php?id=BAC...de=manufacturer[/url] D.[/quote] As with all my designs the J112 requires not only specific T/S specs but also specific driver response. You should be posting your question at [url="http://billfitzmaurice.net/phpBB3/"]http://billfitzmaurice.net/phpBB3/[/url], with links to the driver data sheets showing the manufacturer's axial response charts.

[quote name='Mr. Foxen' post='567269' date='Aug 12 2009, 03:14 PM']Bill almost never elabourates on why he's right, only on why someone else is wrong. I don't think it is in his business interests to do otherwise. When pressed, Claber will write a huge essay that takes several reads to understand. I prefer the latter approach.[/quote] If you want to look into this further there are many sources available. Try Dr. Earl Geddes for one. My personal philosophy regarding posts on forums is that anything worth saying is worth summarizing in a few concise paragraphs, if not a few concise sentences. If you want to be bored to tears read an AES Preprint. My job requires that I read every one when they appear, so I have to suffer through them. Your's doesn't.

[quote name='alexclaber' post='567010' date='Aug 12 2009, 12:29 PM']All the evidence suggests that the group delay of a well designed ported cab is inaudible.[/quote] +1. Group delay is inaudible in the non-directional frequencies, for the same reason that they are non-directional.

[quote name='Badass' post='565953' date='Aug 11 2009, 10:00 AM']I will see if it changes in different spaces.[/quote] It will. This explains why: [url="http://www.padrick.net/LiveSound/CancellationMode.htm"]http://www.padrick.net/LiveSound/CancellationMode.htm[/url]

[quote name='Badass' post='565930' date='Aug 11 2009, 09:32 AM']Think this is on topic... Is this why my small 1x10 practice combo sometimes sounds like the bottom 'E' blooms, for want of a better word? Almost like it is a little flat and them resolves in a split second. (Ashdown perfect 10 - front ports) Or is that the room, or just poor design of the combo. Just curious. As it doesn't happen with my larger rigs.[/quote] A small 1x10 combo will have very little output at the 40 Hz fundamental, and not a lot at the 80 Hz second harmonic. So in the lower notes you're hearing virtually no fundamental, a bit of second harmonic, and a lot of third harmonic, around 120 Hz. The third harmonic is a bit 'off' from what your ear wants to hear as the dominant, and that probably explains it.

[quote name='SS73' post='565688' date='Aug 11 2009, 04:49 AM']Ok that makes sense, but because the ported cab is producing more sound and moving more air, would this not affect speed.[/quote] No. In both cases the cone will move at the same frequency. If the cone is traveling a longer peak to peak distance the actual speed at which it's moving is faster. This doesn't affect what one might refer to as fast versus slow response. If it did then the volume at which one plays, which also changes the distance the cone moves, would change the response. The primary reason why most commercial vented cabs sound significantly different from sealed is poor cabinet design. They simply put drivers into too small a box, resulting in a boomy midbass. It's possible to produce a vented cab with response indistinguishable from sealed, with none of the shortcomings of a sealed cab.