Bill Fitzmaurice

[quote name='Finbar' post='494720' date='May 21 2009, 05:22 PM']Hmm. The idea was to keep it compact and neat, so all to one 3u amp/rack, and two small cabs.[/quote] Not going to happen. Going down one octave doubles the power requirement and requires a speaker that can both handle the power and deliver the response. It won't be compact.

[quote name='umph' post='494286' date='May 21 2009, 09:32 AM']ohmage[/quote]Impedance.

[quote name='dood' post='493648' date='May 20 2009, 02:47 PM']Yes, I think our resident experts have elluded to the fact that putting too many different sized speakers in one box causes all sorts of problems.[/quote] +1. The only justification for a box of that sort comes from marketing departments, who cater to the desires of customers who have no clue how speakers work and will buy anything if it's hyped enough. It's to bass players as Bose is to housewives. One is too big with too many drivers to work well, the other at the opposite end of the spectrum, the net result is the same.

[quote name='bubinga5' post='490940' date='May 17 2009, 05:22 PM']My Q is why was the amp clipping? Was the (so called) Gain to high?[/quote]Yes, especially if his bass was active. [quote]Am i right that ideally you should be using a cab or cabs that are roughly double the wattage of the amp??[/quote] Not really. You use whatever is required to get the volume you need. In most cases an amp can drive to full output a cab that's twice its rating, but that's a very broad generalization. [quote]Also what is the best cab to add to a 2x12?[/quote] Another identical 2x12. If you must go 1x12 make it one from the same manufacturer, loaded with the same driver, with double the impedance of the 2x12.

[quote name='Cornfedapache' post='485222' date='May 11 2009, 12:51 PM']Well that's what I originally thought... So was getting confused when I saw it being talked about to power a stack... Alice Klarr now![/quote]You wouldn't use it to power a stack, but they can be used to drive a power amp that will power a stack. But their main claim to fame is built in speaker emulation circuitry, which is a fancy way of saying they cut the highs and lows and boost the mids, in an attempt to duplicate speaker coloration.

[quote name='Cornfedapache' post='484247' date='May 10 2009, 07:04 AM']Ahh so it's an effects box, of sorts meaning that you can play any amp set up and get teh same tonal results??[/quote]The original intent was to use it as a DI to a recording console, instead of mic'ing an amp.

You're operating under the common misconception that you actually need, or for that matter can use, two channels of 500w/4 ohms. The 320 watts or so available at 8 ohms is more than enough to drive most cabs on the market to full output, while the additional 180 watts you'd get with a 4 ohm load would be inaudible. If Ashdown made companion 4 ohm cabs the next complaint would come from those who felt that they had to use two per channel and why didn't Ashdown make the amp 2 ohm capable.

[quote name='chris_pokkuri' post='480083' date='May 5 2009, 11:54 AM']I'm definately not hung up on a 1x15/4x10 combination (hence my plan for the BigOne) - which is why I asked for alternatives to that combination that would fill out the sound of the band in a way that I can't get from my current setup. I think you are right in that I just liked the improvement in sound from using just the 4x10. Cheers![/quote]If you want to add to a 4x10 I'd do a 2x10, preferably loaded with the same drivers, with impedance twice that of the 4x10. That will give you a system scalable for low, medium and high output requirements.

[quote name='chris_pokkuri' post='479714' date='May 5 2009, 05:04 AM']That seems my most likely route. If I can get a similar volume and sound as the 1x15 + 4x10 weighing in at a total of 180lbs (Thats way heavier than me!) from a lightweight setup of LH1000 + Bigone weighing at under half that, it would be amazing! And I would be very happy <--- See![/quote] Don't get hung up on the 1x15/4x10 route. When you combine virtually any two cabs the sum will sound better than either on its own. All things considered the 1x15/4x10 is a poor combination, albeit a popular one. As to why it's so popular, I repeat : [i]When you combine virtually any two cabs the sum will sound better than either on its own.[/i]

[quote name='SteveO' post='466371' date='Apr 18 2009, 03:42 PM']They do 'what it says on the tin'. Basically some equipment sometimes needs to draw extra current, it's usually the fans when you turn on.[/quote] The high draw is from the power supply caps, which will draw a lot of current when charging at turn-on. Extremely high value caps can appear as virtual dead-shorts for a few milliseconds, and even moderate values will draw far more current when charging than the amp does at full output.

[quote name='Hamster' post='461295' date='Apr 13 2009, 11:01 AM']What we need is someone who really knows about self-build cabinet design to come up with a light and compact design that pumps out buckets of deep bass using the above spec bass and midrange drivers. I'd pay for the plans and build it myself to keep the costs down! [/quote] It's not that simple. You can stick a 1kW capable twelve with 15mm xmax into a 1 cu ft box and get a lot of bottom, but drivers with those capabilities are not the least bit inexpensive, so the advantages over a larger but far less expensive cab aren't worth it even for the average DIY builder.

[quote name='Hamster' post='461219' date='Apr 13 2009, 09:05 AM']Is there a market for a very small and light cab that has tremendous bottom end but with 'shockingly' low sensitivity?[/quote]The problem is that the qualities required of a driver to run to low frequencies at high output in a small box also result in a very low midrange output, demanding a midrange driver; the Acme cabs are an example. That adds to the cost of the cab, as do woofers with extremely high excursion and power capacities, which runs counter to the desires of both the consumer and manufacturer, both wanting to spend as little as possible.

[quote name='alexclaber' post='461096' date='Apr 13 2009, 06:21 AM']they just need to be big. Alex[/quote]Not necessarily. Hoffman's Iron Law allows you to go low and loud while remaining small, but at the cost of sensitivity, which means you need more power and a driver capable of using it. OTOH all other aspects being equal a larger cab will go lower, and the number one defect with most cabs is that they are too small. As for the 'Neo Debate', it's been said before and will be said again ad infinitum by those who's business it is to know that the magnet material in and of itself has no bearing on the sound qualities of a driver. However, neo does allow transducer engineers to come up with combinations of driver specs previously unattainable, and those specs can result in different results than were possible prior to neo. But those results vary from driver to driver, just as results with ceramic magnets vary from driver to driver. Any and all blanket statements regarding specific tone qualities of neo have no basis in fact. In short, some neo drivers do sound different, not because they have to, but because they can.

[quote name='fryer' post='459174' date='Apr 10 2009, 06:54 AM']I have an old Crate amp, producing around 350 w into my Epi 5.3 ohm cab. The cab can take 700 w. I am happy with the sound I get from these. Can I use a power amp with the Crate to provide more power, maybe by bi-amping ?[/quote] If you double your power into the same speaker you'll get an additional 3dB output, assuming the speaker can make use of said power. Chances are it can't; thermal power ratings only tell you how much power a speaker can accept without burning out, not how much it can use, which is on average 60% less than the thermal rating. If you add another identical speaker you'll get an additional 6dB output, assuming your amp can handle the halved impedance load. I doubt your Epi is 5.3 ohms impedance. It may have 5.3 ohms DC resistance, which isn't the same thing.

[quote name='pete.young' post='455780' date='Apr 6 2009, 02:48 PM']Coo, so it is. Under all that foam, a 1" wide slot under the front baffle. Got some more information on the specs from EA - I guess if you want the right answer you have to ask the right question. Alex, you were very close! Fs = 50Hz Vas = 40.3 liters Qe = 0.43 Qm = 11.73 Can't find anything that's an exact match - what's the consequence of having a lower Vas ?[/quote]Vas is the least significant spec, and smaller is generally better. What about xmax? The foam surround of the original usually indicates at least 6mm, which is difficult to find in a musical instrument ten.

[quote name='pete.young' post='454113' date='Apr 4 2009, 09:26 AM']The wiring holes are the only air path from the front of the cabinet through to the middle.[/quote]I doubt that's the case. Look more closely.

The label on the side of the driver looks like Eminence. The foam roll surround indicates a hi-fi style of woofer, not a typical instrument driver. Very similar to this: [url="http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-110"]http://www.parts-express.com/pe/showdetl.c...tnumber=295-110[/url] From the numbers on the tag Eminence should be able to provide specs. BTW, the holes for the wiring should be sealed airtight. Even holes of that size will seriously detract from low end performance.

[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.