Bill Fitzmaurice

[quote name='escholl' post='453625' date='Apr 3 2009, 02:41 PM']Valve amps shouldn't really be run at too high or too low of an impedance -- for maximum power transfer, and to minimize other problems, the impedance should match exactly[/quote]Alex is closer to the fact of the matter. In reality there's no such thing as an 8 ohm or 4 ohm or 16 ohm cab, as every cab's impedance varies with frequency. An average 8 ohm cab actually measures anywhere from 5 to 50 ohms, depending on frequency. SS Amps are designed to operate into the minimum load that they might see, valves into the maximum load that they might see. So a 6 ohm rated cab would pose no problems for an 8 ohm transformer tap. It probably wouldn't bother a 4 ohm tap either, though.

[quote name='guyl' post='453055' date='Apr 3 2009, 05:29 AM']Did you manage to take pictures? The transmission line was a big selling point for these cabs - it'd be interesting to see if it was just marketing boxxxxks![/quote] If less than four feet long it's not a transmission line, at least not one useful in the electric bass pass band.

[quote name='ash_sak' post='452671' date='Apr 2 2009, 02:14 PM']wouldn't the main difference be due to the speaker size and depth.[/quote]No. This is why: [url="http://www.eminence.com/resources/data.asp"]http://www.eminence.com/resources/data.asp[/url]

[quote name='escholl' post='452885' date='Apr 2 2009, 07:18 PM']Yea, i was thinking the same thing there. Glad it wasn't just me wondering why they gave the voice coil size and magnet weight ^_^[/quote] That's information one would find in a catalog, which is undoubtably what 'John D.' was reading from, not a driver data sheet. Most companies don't allow customer service reps to give out driver data, lest they buy a replacement from an alternate source and thus lose a sale. You'd think that they wouldn't be so stingy if they don't have a driver to sell.

[quote name='Mr. Foxen' post='452641' date='Apr 2 2009, 01:30 PM']If it was a 2x15 and had no tweeter, it was likely a sub and only designed to produce low frequencies,[/quote] +1.

Obviously John is in customer service, not engineering. [quote]2.5" dia. voice call with winding length 0.75"[/quote]Moot. [quote]80 oz magnet[/quote]Moot [quote]40 Hz to 2 KHz response[/quote]Moot [quote]Qt between 0.28 and 0.35[/quote] Less than precise. What you do need to know is Fs, Vas, Qes and Qms at the very least. [quote]He also said: "The woofer is connected directly to the amp without going through any crossover components. We utilize the mechanical rolloff of the driver in the overall design to maximize efficiency."[/quote]Definitely customer service; the only reason for so doing is to minimize costs. No engineer would ever try to get away with that statement. You're best off to do the recone, but if you can't find someone to do it for you the above specs are a necessity to get a suitable matching driver. .

[quote name='pete.young' post='448628' date='Mar 29 2009, 08:01 AM']Is there any harm in putting a full-range driver in, even if the crossover circuit means that it's not seeing the higher frequencies?[/quote] The higher the level of engineering the more critical that the correct driver be used. If this cab is as well engineered as rumor has it a different driver would totally muck up the works.

[quote name='Jamesemt' post='444396' date='Mar 24 2009, 05:39 PM']Did that ever get released? No I'm talking about the 2x250 Superfly. I realise the Little Giant 1000 has twice the power, but wondered wether it REALLY has twice the power...if you know what I mean??!![/quote] Even if it has twice the power that's at best a 3dB net output increase, which is barely audible. I can't imagine 250w per side into 2 cabs not being enough; I run only one channel of my Fly into one 8 ohm cab and it's plenty.

[quote name='KASH' post='443693' date='Mar 24 2009, 08:50 AM']Fair enough ...and Alex, thanks for the link mate, good stuff! now...does anyone have this rig or played with it that can give an opinion??[/quote] The 4x10 you list probably has higher output capability than the 1x15, and probably goes lower than the 1x15, so if your intent is to get the most out of adding one or the other the 4x10 is the probable choice. 'Probably' refers to the fact that what limits low frequency output capability is the total driver displacement, and that spec, along with an SPL chart showing actual frequency response, is not available. Anyone who does have this rig will say that the two cabs together sound better than either one on its own. But that's hardly definitive, as pretty much any two cabs together will sound better than either alone. Your only option to know which combination sounds better to you is to try both, side by side.

[quote name='Marcus' post='443096' date='Mar 23 2009, 04:59 PM']Hi Bill..... Of all the bass amp manufacturers i'd be inclined to believe Aguilar....[/quote]Of the hundreds of Theile Small designed reflex cabs loaded with Eminence drivers this is one of them. They have not trod any ground not well covered by numerous others before them. [quote]would I lose any nearfield sound by having driver with a longer throw ?[/quote]No.

You're operating with two basic misconceptions. The first is that 'getting all the watts out of my amp' will make any difference in how loud you'll go, the second is that the specs published by Aguilar are worth the paper they're printed on. That said, you'll get a better result with Eminence 3012HO drivers, which have higher sensitivity than your current drivers, and longer throw. They're only available in 8 ohms, but there's no benefit in going 4 ohms anyway. [quote]I'm sure Aguilar spent a lot of time working out the best driver for the GS/DB112[/quote] Most likely less than an hour. Deciding on a driver for a simple reflex box is a long way from rocket science, and more often than not boils down to whichever Eminence OEM is available at the desired price.

[quote name='alexclaber' post='441316' date='Mar 21 2009, 04:53 PM']Specs are certainly creative things... Alex[/quote]You can't easily tell a 2512 from a 3012, and they very well could be 3012 OEMs. Those have only been available for about 6 months, so if older they're 2512s. While the stock 3012 is rated 450 watts OEM drivers aren't rated as high. Not that they aren't as good, but Eminence only does full bore Klippel testing on their in-line models, so OEM versions that haven't been as thoroughly torture tested are more conservatively rated.

[quote name='ped' post='437036' date='Mar 17 2009, 07:26 AM']Hi mate, I used to have a BAsson 210 cab and although it sounded great, it was extremely heavy and, more importantly, very power hungry.[/quote]True of the Basson ten loaded cabs, which use very heavy drivers that have poor low frequency sensitivity. The B15B doesn't suffer those maladies, being loaded with an Eminence Delta 15 that's of moderate weight and adequate sensitivity. However, the Delta 15 has a paltry 2.7 mm xmax, which displacement limits it to only 50 watts capacity through most of the bass range. That makes the Delta 15 unsuited for use in other than a low power combo.

[quote name='bass_ferret' post='434998' date='Mar 14 2009, 09:43 PM']Why a 210 and 112? I would be inclined to have two of either rather than one of each.[/quote] +1. There's little point in combining tens and fifteens, even less in combining tens and twelves. Find a cab you like the sound of, buy it. If it's not loud enough buy two.

[quote name='KASH' post='433645' date='Mar 13 2009, 09:57 AM']Does mixing 2 different GK cabs (410RBH with 115RBX or vice versa) affects the sound in a positive or negative way? Any thoughts on mixing cabs?[/quote]It's impossible to predict what mixing different cabs will do, and that's the main argument against so doing unless you've tried the specific combination to be sure you like it.

[quote name='eddies left thumb' post='429713' date='Mar 9 2009, 03:38 PM']thanks, seems the best advise is dont think you know more than Mr trace elliot[/quote] Not necessarily. Many manufacturers choose their drivers primarily based on their cost, not how well they work, and the majority of manufacturer's don't design their own cabs, but have it done for them by independent engineers, whose driver spec recommendations aren't always heeded. Most cabs can be loaded with better drivers. The problem lies in finding out exactly what the specs are on the drivers in your cabs to see if there's room for improvement. That's not information most manufacturers are willing to divulge. [quote]i was thinking of upgrading them to the celestion neodymium orange series as i like a well defined bass sound and there description sound right to me.[/quote]The Orange series have very poor specs for electric bass. The Green series are far better, though still less than spectacular.

[quote name='bass_ferret' post='433206' date='Mar 13 2009, 03:54 AM']Probably [/quote]+1. Why are you adding the 1x15? To get more low end. Google Hoffman's Iron Law. Simply put if you want to go lower you must either have a larger cab or a lot more power. If you have two cabs of the same size and same power the one can not go significantly lower than the other while maintaining the same output level, irrespective of what size drivers you use. This goes to laws of physics, which is not trumped by either opinion or advertising. Adding a second cab will get you more output, but so long as it is the same size and driver displacement it really doesn't matter all that much what's in it. And since the average 4x10 has more displacement than the average 1x15 adding another 4x10 will give you more output than adding a 1x15. Which is what I said five pages back.

[quote name='redstriper' post='430714' date='Mar 10 2009, 12:57 PM']OK - so which specific cab/driver combination would you recommend?[/quote] One that uses a fifteen with no less than 8mm xmax. In the electric bass genre you're as likely to be able to get that information as for the Queen to give you her crown. I believe Alex is currently the only UK source that divulges the specs on the drivers he uses.

[quote name='Sharkfinger' post='430158' date='Mar 10 2009, 06:03 AM']Going back to the original question, what advice would we give fekalizatorius?[/quote] The point of this overblown exercise has been that adding any 1x15 willy nilly will as likely work no better than adding a 2x10, and the 2x10 will give a better modular rig. Fifteen inch drivers that actually work better in the low end than his current 4x10 do exist, the trick lies in finding out if one of those drivers is what's contained within a particular cab.

[quote name='stevie' post='429495' date='Mar 9 2009, 12:05 PM']I’m not suggesting anything other than that there is a relationship between fs and cone size.[/quote] Only in the most peripheral way. Size and fs would only be somewhat proportional if all cones were made of the exact same material. They aren't. Otherwise eights with fs values an octave lower than eighteens, and vis-versa could not exist, But they do. To suggest that driver size and fs are intrinsically linked displays lack of a fundamental understanding of driver design. [quote]OTOH, given the ratio of cake height to radius (which is approximately constant between the Pie and the Gateau[x]) what would happen, theoretically, if I had a cylinder with a smaller surface area (cake top) but greater 'excursion' (cake height) - e.g something like Tesco's Value chocolate sponge roll.[/quote] A simpler analogy is that sixteen one ounce weights and one sixteen ounce weight both weigh a pound. Even better: you'll get just as drunk after quaffing two pints as you will with one quart.

[quote name='joegarcia' post='428689' date='Mar 8 2009, 12:54 PM']What exactly is wrong with them then?[/quote] Guitar drivers loaded in a cab of half the volume required shoddily built from inferior materials. But otherwise OK.

[quote name='Mr. Foxen' post='428668' date='Mar 8 2009, 12:29 PM']Did it have some advantage like better treble dispersion, or was it just how to fit speakers in a different sized box?[/quote]Most likely too much weed. California in the '70s, dude. Fender cabs were never shining examples of how to build bass cabs, more often than not being the opposite. This oddity represents their nadir.

[quote name='Mr. Foxen' post='426626' date='Mar 5 2009, 03:12 PM']The fact that they are in the same enclosure might defeat some of the 'advantages' of the 4 vertically arranged layout though.[/quote] There are no advantages to four vertical drivers when there are four more adjacent to them.

[quote name='Sharkfinger' post='426154' date='Mar 5 2009, 08:51 AM']So what I'm getting from this, right or wrong, is that by a rule of thumb the more cone surface area the more LF is produced,[/quote] Surface area is only half of a two part equation. What counts is surface area (Sd) multiplied by excursion (Xmax), the result being displacement (Vd). However. as your assumption is shared by the vast masses, it's one capitalized on by the marketeers, who want you to think that you must go larger to go lower, and in so doing hopefully expanding the contents of their coffers. The other side of that coin is that even amongst manufacturers that do possess a social conscience none are going to refuse to build anything that isn't justifiable so long as there's demand for it.

[quote name='Mr. Foxen' post='426571' date='Mar 5 2009, 01:58 PM']In two columns of 4 vertical speakers. Haha, I see at least one of Bassferret, Claber and BFM coming into this thread to suggest that.[/quote] It doesn't matter, it won't sound any different. The fault with an 8x10 lies in having drivers side by side, not in how they're wired. [quote]Anyway, I have an Ashdown 8x10 that is 4 ohm, and was thinking that if I put an Ampeg style thing into it, so I can run it as two 4x10s and can run both my lower powered valve heads that only do down to 8 ohms into it.[/quote]Unlike SS valve heads have no minimum impedance load, they have a maximum impedance load. Your proposed mod is probably more trouble than it's worth.