Bill Fitzmaurice

[quote name='Bass Culture' post='649986' date='Nov 9 2009, 02:21 PM']"With only 2.5mm excursion and 69Hz Fs IMO the BN12 300s is a poor choice for electric bass. The BL12 200X will go a half octave lower and take twice the power before running out of steam". And what's your view on the Neo version of the same speaker, Bill - the BN12 300X (I don't know why but it appears the Neo 12" Green Label is rated at 100w more.)?[/quote] The 300x is also OK, but that extra 100 watts thermal won't be of any benefit, as with 4mm xmax they're both displacement limited to 150 watts, give or take.

[quote name='ColinB' post='649363' date='Nov 9 2009, 03:09 AM']I wouldn't know if putting the Orange 12" speaker in a different cab design to that which Warwick use could increase the bottom end, or if swapping the Orange for a Green in the same cab would achieve anything worthwhile - probably not![/quote]With only 2.5mm excursion and 69Hz Fs IMO the BN12 300s is a poor choice for electric bass. The BL12 200X will go a half octave lower and take twice the power before running out of steam.

[quote name='Bass Culture' post='648143' date='Nov 7 2009, 10:31 AM']Ahhh, so there's a question to be asked then... Thanks, Mark[/quote]If you ask that question of the usual sources, Ampeg, Fender, Eden, etc., you'll get no answer, as they don't have that information available. But any custom builder should, and if he doesn't, look elsewhere. Better service than what the usual sources can provide is the only reason for having a cab built for you.

[quote name='Bass Culture' post='648134' date='Nov 7 2009, 10:16 AM']I'm having two of Mike Walsh's Purple Chili 12" bass cabs made for me and I'm trying to decide whether to go for the orange label or green label neo speakers. There's a difference in sensitivity and frequency response between them as well as fundamental tone - by the sound of it. The green's are supposed to be more 'old school' and the oranges more mid-biased and clear. As each speaker seems to have different strengths I'm thinking of having one cab made up with each. Anyone had any experience of these speakers or care to comment on the one of each option? Thanks, Mark[/quote]The most important spec is excursion, xmax. That's what determines how much low frequency output a driver is capable of. IMO anything less than 4mm disqualifies a driver from consideration. And don't mix drivers, there are no advantages to doing so. As for the result you can expect, a builder who knows what he's doing will be able to model different drivers in different boxes and provide you with charts for response, sensitivity and maximum output. Ergo, if he can't provide you with those charts...

[quote name='stevie' post='647276' date='Nov 6 2009, 09:27 AM']I was thinking of the LAB12 woofer that Eminence built (and still builds) for Tom Danley's Lab horn, which was more advanced in certain respects than the drivers Eminence was making at the time. It has an xmax of 13mm, for example.[/quote]The Lab 12 is built on the same frame used by Eminence for a number of drivers, the Dayton (Parts Express) Titanic 12, which pre-dates the LAB, being one example. The magnet, coil, cone etc. are all stock items. The only part that might have been created specifically for it is the dome, though that might have been a stock item as well. It differs from most Eminence offerings being built on a consumer sound frame, not a pro-sound frame. Eminence makes many OEM consumer sound drivers, but only markets pro-sound drivers under its own brand.

[quote name='Musky' post='647118' date='Nov 6 2009, 07:05 AM']Yeah, I didn't really think there was any such thing as a 'super driver', or the manufacturers would be making them as a standard model! I'd rather assumed that the whole 'custom driver' thing was mostly snake oil, with an implied superior performance.[/quote]Leo Fender pasted 'Special Design' stickers on the drivers he used and the only thing special about them was the sticker. He used stock drivers, purchased from a number of companies, which ones made it into a particular production run depended on who gave him the best price.

[quote name='umcoo' post='645784' date='Nov 4 2009, 05:19 PM']Hey Basszilla, does it make it more grindy and gainy, or just a clean boost?[/quote]It's not going to do a lot, since the two channels are paralleled into a common power amp. You can get a lot more utility if the two channels are cascaded in series, but that takes rewiring by a good techie.

[quote name='Musky' post='644136' date='Nov 3 2009, 04:00 AM']I was wondering how much manufacturers can customise a speaker?[/quote] Very little, unless they're ordering in lots of 10,000. Eminence offers a number of OEM options, most of them built with existing parts, a frame from this pile, a cone from that pile, a voice coil from that pile and so forth. The frame and motor very much determine a useful parameter range that can only vary by roughly 20%. There are no OEM 'super drivers' with specs that can't be very nearly duplicated with an off the shelf unit. The Ampeg driver is a bit unique, because it's built with a frame and motor that hasn't been used for any of Eminence's in-line drivers for at least ten years. If it was any other manufacturer they wouldn't do enough volume to keep making it. Save impedance its specs fall into the range in between the Alpha 10 and Beta 10. Recently some 32 ohm neo replacements have appeared, which probably use the Basslite S2010 frame/motor.

[quote name='umcoo' post='643748' date='Nov 2 2009, 02:24 PM']Hi folks, I recently picked up a Fender Bassman 135, but am waiting on funds for a cab (but that's another story). I've heard about patching a cable between the bass and normal channels, but want to know what happens and how it affects the sound and tonez. Any users out there?[/quote] We used to do that with Fenders in the 60's, it allowed you to use the deep switch on the bass channel and the bright switch on the instrument channel, but it wasn't particularly worthwhile. The EQs on the two channels were identical, so no benefits there. One possible use that would be worthwhile is to run one channel straight and effects through the second, giving the ability to vary the tone and volume mix of straight and effect.

[quote name='Finbar' post='643683' date='Nov 2 2009, 01:19 PM']Well I don't know, the clip light wasn't engaging, so I can't have been running it that hot...[/quote] Hot enough, obviously.

[quote name='Archetype' post='642833' date='Nov 1 2009, 04:05 PM']Hey everyone, I am getting my mits on a bunch of Delta 12 speakers[/quote] Sell them. Delta 12s are poorly suited to electric bass. When it comes to building a cab the best route is to find a tested design and then load it with drivers that are recommended for it.

If you're going through the PA then your sound will only be as good as the guy at the FOH. IME most are clueless on how to mix bass. If you want to capture the sound of your speakers you must mic, though FOH guys who really know what they're doing will DI one channel for below 100Hz and mic another for above. But no matter what you use for sourcing it's still all in the hands of the FOH engineer. A good one can make anything sound great, a hack will screw up the works no matter what.

[quote name='AttitudeCastle' post='635908' date='Oct 25 2009, 05:39 AM']Hey Guys, Any one know why the BA115 and BA115T were discontinued?[/quote]Still on the Ampeg website. Some on line dealers list it as sold out, could be part of the ongoing LOUD problems, many Mackie products are also MIA.

[quote name='Nostromo' post='636272' date='Oct 25 2009, 12:53 PM']Thanx for that Bill, If I went the ported route with higher power speakers in mind, can you offer any advice on how big the port (or ports) would be[/quote] 45 Hz is a good all-purpose tuning frequency, and 4" ID tubes match well with a 12 inch driver. A pair 5 inches long installed through the back would do. Be sure to line the entire cab with an inch of convoluted foam padding or polyester batting.

[quote name='Nostromo' post='636193' date='Oct 25 2009, 11:30 AM']Thanks Bill, Interesting stuff . . . . I cant help but ask . . . . what speakers would you recommend ? Cheers, [/quote]I'd be venting the box for Deltalite II 2512s, or 3012HOs should you ever want to go with more power. Technically the 2512 with an EPB of 84 is sealed cab friendly, but the Beta 12 is less expensive and has a bit better low end sensitivity in a sealed box. The 2512 and Beta 10 are similar in the low end in a vented box, but the 2512 has a better midrange.

[quote]However, not a single one of them has a EBP of less than 155 and most are in the 200 / 300 range . any thoughts Bill ?[/quote]You can use a high EBP driver in a sealed cab, you just won\'t get any bass response from it. [quote]Im beginning to spot a correlation between higher power handling and higher EBP here[/quote] Pure coincidence. [quote]maybe vintage speakers tended to have a low EBP ?[/quote]Nope. Look at old JBLs and EVs. The main reason why sealed cabs dominated until the mid 70s was the lack of widespread knowledge of how drivers functioned, and that applied to the people that made them as well as everyone else. That knowledge was quantified by Theile and Small in the mid 1960s, and it took ten years before the electric bass cab industry began to take notice. A good argument can be made that many manufacturers still haven't caught on.

[quote name='Monz' post='635622' date='Oct 24 2009, 04:09 PM']As far as I am aware "Infinite Baffle" means the wood that the drivers are attached to is an integral part of the cabinet construction i.e. stressed member[/quote]Infinite baffle is where the front and rear waves of the driver are isolated from each other. That may be via use of a 1/2 cubic foot sealed box, it may be by mounting woofers in a wall between two rooms of a house. The roughly 4.5 cu ft cab of the OP will work well sealed with drivers that have an EBP of less than 75, vented with drivers with an EBP of more than 100, with in between 75 and 100 being OK either way. Delta Pro 12s would require the cab be vented and tuned to 45 Hz. To stay sealed the Beta 12 would work better.

[quote name='alexclaber' post='635251' date='Oct 24 2009, 07:59 AM']if the slope and frequency of the internal passive crossover is different to the active crossover on the GK then it'll make the cab sound different.[/quote]Maybe, but that might not be a bad thing. The intent of the G-K is to allow overdriving the lows while keeping the highs clean so as not to harm the tweeter. It's a good idea, but somewhat flawed in the execution, as the G-K highpass is fixed, so you can't adjust it to suit whatever tweeter it's used with.

[quote name='trent900' post='635016' date='Oct 23 2009, 07:33 PM']A mate of mine who knows a gnat or two about electronics (or so he says) suggests opening up the back of the Epi and modifying it so that it also can use the GK's horn amp with a 4-way cable. Jon[/quote]It could work very well if the tweeter is designed to operate at the same crossover frequency as the G-K. But if not it could be a problem so you'll have to be sure of that.

Could be the driver exceeding its excursion limit, maybe even the coil hitting the backplate, it could be the amp out of headroom also. The added excursion and power demand that results from boosting the low EQ could cause both symptoms.

[quote name='zephead' post='634031' date='Oct 22 2009, 06:57 PM']errrrrrrrrrrrr........................what are they?[/quote] They're of little use with cabs that aren't specifically designed to work with bi-amping, and of the current crop of commercial bass cabs there are none. You'd have a fair enough result with a 2x15 for the bottom and a 2x10 sealed guitar cab on the top, using around 300 Hz for the crossover frequency, but with two bass cabs running both full range will probably work better.

[quote name='waynepunkdude' post='632946' date='Oct 21 2009, 05:34 PM']It's this one. [url="http://www.samsontech.com/products/productpage.cfm?prodID=1691"]http://www.samsontech.com/products/product...cfm?prodID=1691[/url][/quote]There's not one useful bit of information there that might indicate how it will actually work, but that's not the exception, it's the rule.

[quote name='Mr. Foxen' post='632484' date='Oct 21 2009, 10:54 AM']People do have a habit of writing about it on the internet though.[/quote]That they do, but consider that the specs on probably the most envied driver, the original CTS Ampeg SVT, are not to be found anywhere. For that matter those on the current Eminence SVT driver are also unavailable. I've got them, but like all those in the industry I won't reveal them, as it's privileged information. As for measuring them yourself, unless you've got a Klippel analyzer handy, or tear the voice coil out to measure the coil length and plate thickness, that all important xmax remains an unknown. It's easier to just schlep your rig into a store and try cabs.

[quote name='Mr. Foxen' post='632407' date='Oct 21 2009, 09:37 AM']Find out what speakers are in it[/quote] Good luck. Most manufacturers are less forthcoming about the drivers they use than Joan Collins is with her birth date.

[quote name='waynepunkdude' post='632109' date='Oct 21 2009, 04:28 AM']I'm looking at a 2X15 that is 500W @ 4OHMS my 4X10 is 600W @ 8OHMS would the uneven load cause a problem or will it be fine as it is off of 2 separate power amps?[/quote]It won't bother anything, but beware of power ratings that are meaningless, which most are. What counts isn't the thermal rating, it's the displacement limited rating, and no one provides that. Try before you buy.