Bill Fitzmaurice

Technically any Gamma 12s are NOS, new old stock. Production of them ceased a number of years ago.

[quote name='51m0n' post='1287713' date='Jun 30 2011, 08:52 AM']you will still get boundary effect with the bottom 2, maybe even 3 speakers and the floor.[/quote] You will get the full boundary loading effect with all the drivers, as they will be spaced close enough together to fully mutually couple in the bass frequencies, essentially operating as one large driver.

[quote name='Thurbs' post='1287595' date='Jun 30 2011, 07:48 AM']You could put them both on their sides to arrange the drivers vertically and watch the middle of the audiance wonder where all the bass has gone... [url="http://www.astralsound.com/bass_pattern.htm"]http://www.astralsound.com/bass_pattern.htm[/url][/quote] Methinks you misunderstand the link you posted, as it (correctly) states exactly the opposite of what you seem to think it states. Those diagrams show the overhead view of the stage and audience, and display why cabs (and individual drivers) should not be horizontally arrayed.

[quote name='muttley' post='1286649' date='Jun 29 2011, 11:57 AM']Yes, I knew about the dominance of neo in PA. It's not [i]that[/i] long that I've been out of the industry . But for MI, do you mean non-guitar applications?[/quote]Guitar is the one area where neo has not yet made major inroads, because most guitar drivers don't use very large magnets nor have high xmax values.

The Ampeg driver has 4.7mm xmax, the 2510 4.2mm. That gives them virtually identical output capability.

[quote name='muttley' post='1286462' date='Jun 29 2011, 09:26 AM']I've been out of the game for a few years now so don't know what the latest thought is on neo[/quote] More than a few I'd say. Neo has owned the high end PA genre ($5k and up per cab) for a decade, musical instruments for the last five years. But as of recently the price has skyrocketed due to predatory trade practices by the Chinese. And Eminence didn't get to be the #1 driver manufacturer in the world by producing crap.

[quote name='Neuroscar' post='1286020' date='Jun 29 2011, 02:25 AM']Im thinking about making my own 15" cab[/quote]Only do so if all of this makes perfect sense and you know how to make use of it: [url="http://www.eminence.com/support/understanding-loudspeaker-data/"]http://www.eminence.com/support/understand...udspeaker-data/[/url] [url="http://www.linearteam.dk/default.aspx?pageid=winisd"]http://www.linearteam.dk/default.aspx?pageid=winisd[/url]

[quote name='Lozz196' post='1285850' date='Jun 28 2011, 05:51 PM']Ok, been doing a bit of reading over on T*lkb*ss, and there seems to be a fair appreciation for Eminence Basslite S2010s. I`ve also found out from Eden that the speakers in my cab are their Chinese made cones. So, would the Basslites be an improvement, and offer me a tone nearer to that of an Ampeg than what I have now?[/quote] Impossible to say without either seeing response charts for both (Eden does not publish any, as it would reveal their SPL claims to be rubbish) or having cabs with both drivers side by side.

[quote name='Merton' post='1284755' date='Jun 27 2011, 05:49 PM']Sorry for going OT here but when did Eden stop making their own drivers? Was it around the time of the US Music takover or when David left?[/quote]Eden's a bit cryptic, so I can't say for sure if they're still making any ceramic drivers or have gone completely to Eminence, but their staple driver was the 1060, and they now use the 1040 in Nemesis, probably Eminence. Their Neo is Eminence. The Ampeg drivers aren't all that heavy, 6.7 pounds, so four of them are only eight pounds heavier than four neo tens. Any other weight difference would be in the cab.

[quote name='Lozz196' post='1284593' date='Jun 27 2011, 03:44 PM']I`m thinking of changing the speaker cones in my Eden Nemesis 410, to either Eminence BP102 or B102 cones, to try and get a more Ampeggy sound, figuring that as Ampeg use Eminence speakers, that is logical[/quote] The cab and driver must be matched to work well. With older Edens when they made their own drivers you really needed to use Eden replacements. They now use Eminence, so there's probably nothing to be gained by swapping them. As far as what Ampeg uses, they bear no resemblance to either the BP102 or B102. The B810 is a direct replacement, but if you don't have a sealed cab you won't get Ampeg tone. And the cab is only half the equation. It takes an Ampeg head as well.

[quote name='Al Heeley' post='1281084' date='Jun 24 2011, 09:58 AM']I'm not sure I fully understand this, Bill. Are you saying that a 1 x 15 in series with a 2 x 10 (proposed setup) is different to having a 4 x 10 in parallel to a 1 x 15 (current setup)?[/quote] I'm saying forget about the 210, use the 115/410 as you have been, aiming the 115 at the drummer, and never split bass cabs.

[quote name='chris_b' post='1280435' date='Jun 23 2011, 08:57 PM']When I played a 210 and 115 Basschat told me that using different speaker sizes gave me problems, but it didn't! Now I'm being told I have a problem because I stack my cabs the wrong way. I don't![/quote] What you've actually been told is that there are logical alternatives to the willy-nilly tossing together of different speaker/driver combinations and equally willy-nilly tossing of cabs onto the stage with no regard to how soundwaves actually function. It's your option to ignore those alternatives, just as it's the option of others to investigate them and employ them should they find it appropriate for them.

[quote name='Mr. Foxen' post='1280965' date='Jun 24 2011, 08:35 AM']That is much less expensive than I was anticipating.[/quote] Very reasonable, and invaluable as you can use it to measure not only the raw driver but also the finished cab. It will do an impedance sweep in two seconds.

[quote name='Mikefwlr' post='1280931' date='Jun 24 2011, 08:13 AM']EA seem quite secretive about the specs for their cusdtom drivers. Guess i could measure the impedance with a multimeter (but i don't have one), anyone know the specs of these woofers?[/quote] This is what you need to measure specs: [url="http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-804"]http://www.parts-express.com/pe/showdetl.c...tnumber=390-804[/url] I seriously doubt that the EA driver is at all dissimilar to an off the shelf Eminence, but they won't say, and until someone goes to the trouble of measuring the drivers themselves it will remain a mystery.

[quote name='Al Heeley' post='1280547' date='Jun 24 2011, 04:24 AM']Just bought a 250W Hartke VX 2x10... to position just behind the head of our drummer to help him keep time.[/quote]Bad idea. Splitting low frequency cabs will result in all sorts of phase sourced cancellations. What you should do is simply turn the 1x15 (which I assume is below the 4x10) to face the drummer. That will provide him with the mids he needs to hear, while keeping all the lows sourced from the same point. By the same token should you ever run the bass into the monitors it should be high-passed on the board at 100 Hz, providing the mids to the band to hear you while not causing phase cancellations in the lows. If you must have the 210 near the drummer it should be driven by a separate amp with the lows rolled off for the same reason.

[quote name='Monckyman' post='1279540' date='Jun 23 2011, 07:27 AM'] That`s me told! I might remind you though, that this is supposed to be fun, otherwise we`d all be accountants.[/quote] Knowing what you're doing doesn't make designing and building speakers any less fun. It does save more than a fair share of time and trees.

[quote name='Grand Wazoo' post='1278990' date='Jun 22 2011, 03:18 PM']a rear ported cab behaves differently if placed on the floor that it would if stacked high.[/quote]The direction the port faces makes no difference. Any perceived tonal difference is purely the result of hearing your mids and highs better. [quote]Spacing the speakers further apart lowers the maximum frequency at which they will couple coherently[/quote]Only on the vertical plane, which doesn't affect what the audience hears, and only affects what you hear if you're very close to the cab, as in less than six feet or so.

[quote name='Monckyman' post='1277822' date='Jun 21 2011, 05:11 PM']Martin, I`m with you. You learn about this stuff by sawing wood, not entering numbers into software.[/quote][i]Any sufficiently advanced technology is indistinguishable from magic.[/i] There's nothing the least bit magical about loudspeaker design, and all you need to learn how to design them is the ability to read and desire to advance your knowledge. Learning how to do this 'stuff' by sawing wood is how it was done when better means did not exist; that era ended with Thiele and Small circa 1965. The only thing that software has done is to remove the need to wade through mountains of equations. If your personal preference is to remain technologically in the dark that's your prerogative. Advising others that they should do so as well, not so much.

[quote name='Phil Starr' post='1275551' date='Jun 20 2011, 03:52 AM']All this meant that most speakers were in boxes that were often too small and that the designs were often under damped meaning that you got a nice warm bass frequency hump at the expense of deep bass.[/quote]True for the most part, because most drivers of that period out of the Jensen/Celestion mold had high Q values. That made them best suited to large sealed cabs. However, JBLs were at the opposite end of the scale, with very low Q values. That made them best when used in small vented cabs. Yet you would find both JBLs and Jensens/Celestions used[i] in the same cabs[/i]. Fender used the D130F and D140F in a large volume per driver vented Showman cab and a small volume per driver sealed Dual Showman cab. Why? Because they didn't know any better. What science that did exist in the field of loudspeaker cabinet design in that era was very much restricted to the theatrical and hi-fidelity genres, being totally unknown in the musical instrument industry. That's why searching out a cab of that period, or a design for same, is of highly dubious value.

[quote name='Nostromo' post='1274087' date='Jun 18 2011, 03:28 PM']I wouldn't know what effect that would have on the sound/tone/character of the cab ? . .[/quote]Not that much. They did manage to get a pretty good result with some of those old cabs. But it was all trial and error, and with a software designed cab there's no trial, and more important, no error. You can get the best possible result from the drivers used with the smallest possible cab. For example, the JBL 4625 electric bass cab loaded the E140 into a 127 liter (net) 40kG cab. It embodied the best of what designers knew circa 1980. It's twice the size and weight required.

[quote name='Mr. Foxen' post='1273870' date='Jun 18 2011, 11:03 AM']He is looking for a 70s design, not looking to design a new cab. A 70s speaker in a 70s design cab that would have had that speaker in will give you a 70s sound, which I would kind of hope is his design goal here. Suggesting he make a new design, with knowledge he doesn't have applied to specifications that aren't available is astoundingly unhelpful.[/quote] If advising someone to use an archaic intrinsically flawed design that doesn't bring out the best that the drivers used can offer is helpful I'll always choose to be unhelpful, astoundingly or otherwise. But I won't deny the value of those 60s cabs, having to suffer their inadequacies was the impetus for my learning how to design better cabs than I could buy.

You'd design a cab for D140s the same way as you would for any other driver, using a program like WinISD Alpha Pro and the driver T/S specs. Specs for the D140 are not available, unless you measure them yourself, but those for the D130 will be close enough, as it was almost identical. Copying a vintage cab wouldn't get you anywhere near as good as a result, as those cabs were all 'seat of the pants' designs that worked far from as well as possible. Take the Sunn, for instance. That is[i] not [/i] a rear-loaded folded horn. The designer, Conrad Sundholm, didn't even know what a rear-loaded folded horn was, let alone how to design one. He'd just seen the term and used it to describe the 200S, despite not having a clue what it meant.

[quote name='MatthewKeys' post='1269471' date='Jun 14 2011, 07:02 PM']Is there any problems with leaving a cabinet in a car for a long period of time? like, for weeks?[/quote]As long as you won't mind it when you find it gone.

[quote name='LawrenceH' post='1266057' date='Jun 12 2011, 08:53 AM']Manner, please! This isn't talkbass[/quote] Point of order, but acoustical engineers don't refer to accepted acoustical engineering practice as 'old wives tales', so clearly Phil does not earn his living designing loudspeakers. Not good speakers, anyway. And being named Phil I doubt that he is himself an old wife either. If she is her parents owe her an apology for giving her a gender inappropriate name.

[quote name='Phil Starr' post='1263233' date='Jun 9 2011, 03:40 PM']All this stuff about not mixing drivers is just an old wives tale.[/quote]And old acoustical engineers. From your response I gather you're neither. The advantage to identical drivers is that you always know what you'll get. With mixed drivers you never know what you'll get until you've got it, and that can turn out to be an expensive experiment.