Bill Fitzmaurice

[quote name='Jean-Luc Pickguard' post='1022818' date='Nov 13 2010, 02:32 PM']having a cab braced up to its eyeballs won't stop people from stumbling into things.[/quote]Agreed, that's where having a cattle prod handy works a treat. My drink is welcome atop my amp, but no one approaches my rig.

[quote name='icastle' post='1024126' date='Nov 14 2010, 06:23 PM']Has anyone tried one of these? [url="http://www.auralex.com/sound_isolation_gramma/sound_isolation_gramma.asp"]http://www.auralex.com/sound_isolation_gra...tion_gramma.asp[/url][/quote]There are circumstances where they're helpful, as in flimsy stages. The main factor they're intended to address is transmission of cabinet vibrations into the floor, but unless your cab is really poorly constructed the vast majority of floor excitation is caused by acoustical transmission, not mechanical, so a pad won't stop the floor from vibrating. It will isolate the cab from those vibrations, though.

My Super Fly would get quite hot if not fan cooled, so I added one. I assume that was a lesson learned by Ashdown as well. I'd have the thermistor bypassed to run it constantly, especially as the thermistor seems non-functional anyway.

[quote name='Jean-Luc Pickguard' post='1022493' date='Nov 13 2010, 09:54 AM']No one puts a pint on top of my rig no matter how level it is[/quote] Ah, you prefer a fifth then? Perhaps a bit OT, but if you can't put a pint or whatever atop your rig without it doing St. Vitus dance it indicates insufficient bracing of the cab. Aside from the issues of where to put your drink any energy expended in vibrating cabinet walls is energy not making it's way to the audience as sound. The two corners most often cut by cab manufacturers are bracing and damping, as you can't see if they're properly in the cab without opening it up. Tilt backs are a good idea in a combo, as combos should be tilted back so you can hear the mids. The reason for a dearth of them is the same reason why most acoustically valid concepts see limited usage, and that would be how it looks.

[quote name='makatak' post='1022138' date='Nov 13 2010, 01:22 AM']Ive never noticed the fan coming on .[/quote]That indicates a problem.

[quote name='rOB' post='1022273' date='Nov 13 2010, 06:07 AM']why aren't there more kickback/wedge shaped amps/cabs on sale?[/quote] Because you can't place a pint atop it.

[quote]Jesus, no wonder Alex stopped posting... I wouldn't be surprised if Bill went the same way.[/quote] I'll continue to post for the benefit of those who are interested in learning how speakers work. I won't argue with those who aren't. In light of the fact that stevie clearly has no interest in anything but arguing I've put him on my ignore list. [quote]If 4x10 cabs are wrong , then why do people keep buying them[/quote]Because they don't know that the configuration is flawed. [quote]Bass cab companies seem happy with two wavelengths spacing (as in a 4 x 10).[/quote]Bass cab companies are like all companies. They're happy with anything that sells.

[quote name='Phil Starr' post='1021019' date='Nov 12 2010, 04:20 AM']Good advice. This will filter out the signal at about 400Hz[/quote]Filtering a 2x10 that's designed to work to 60 Hz or lower at 400Hz is going to cost a lot of midbass output. That's OK if you don't need that output, but then you're schlepping around a lot of cab for no good reason. Fully 3/4 of the cab's size is there to allow it to go that low.

[quote name='Mr Rabble' post='1020054' date='Nov 11 2010, 08:53 AM']2x10" have more surface area than a single 15"[/quote]They don't, but it's moot. Research [i]displacement limited output[/i].

[quote name='tomtraubert' post='1020029' date='Nov 11 2010, 08:34 AM']any thoughts on why they aren't more popular?[/quote]Too big. Get a pair of 2x12 instead.

[quote name='stevie' post='1015105' date='Nov 7 2010, 06:28 AM']A vertical column is quite often not the best way of arranging multiple drivers, particularly bass drivers.[/quote]One can run drivers horizontal so long as their center to center distance is less than one wavelength within the pass band. This basic law of acoustical engineering is almost universally ignored by the electric bass cab industry. (I doubt most manufacturers are even aware of it.) Drivers offset on the diagonal can sometimes come close, though.

[quote name='machinehead' post='1012814' date='Nov 4 2010, 08:44 PM']If they're using the Kappalite 3012HO or a driver of equal spec[/quote]They aren't. Its a 2512 motor.

[quote name='ThomBassmonkey' post='1014312' date='Nov 6 2010, 10:41 AM']why make a vertical 4x10 which would stuggle to be transported when most people (myself included) would go for 2 2x10s[/quote] My preference would be for the two 2x10s, but there are those who prefer a high cab that's essentially its own dolly for wheeling about, and don't mind the weight when stairs are encountered. For them a tall 4x10 would be the ticket, but I wouldn't hold my breath in anticipation of ever seeing one. An option would be a pair of dedicated 2x10s with wheels on one, a top handle on the other, and clamps to tie them together for wheeling about. The clamps would also ease concerns about stability on stage.

[quote name='Protium' post='1013803' date='Nov 5 2010, 06:08 PM']Or because no one has space to store or transport a seven foot tall 8x10 [/quote] Modern driver technology allows for a vertical 4x10 to perform as well as an 8x10. No one makes one because 'it wouldn't look right'. A pair of good vertical 2x10s is very much the same thing anyway, but note the comment by the previous poster being concerned about how they look without a word mentioned about how they'd sound. Ask Alex about the sales resistance he gets because his cabs don't look like they came from the same cookie-cutter mold that most cabs have since 1959.

[quote name='Alien' post='1013397' date='Nov 5 2010, 11:18 AM']AFAIK, the TNT150 was fitted with either a Scorpion or a Black Widow as standard, depending on the year. I'd have said yours looks to be a BW. A[/quote]Looking more closely the driver has squared edges. BWs have a round frame, as do the Blue Marvel(low end Eminence OEM, actually), so it's probably a Scorpion. If it is the same as the current SP-15825 it's a fair enough driver, but not worth putting into a fEarful or Barefaced type of box. It would work OK in an Omni 15, but with 3.1mm xmax is only good for 150 watts, so it would be a limiting factor in the long run.

[quote name='Rich' post='1012899' date='Nov 5 2010, 03:48 AM']I used to run 1x15 + 2x10. I swapped the 2x10 for a second 1x15 and now the sound is bigger, louder, more everything. Far better.[/quote]If you'd swapped the 1x15 for a second identical 2x10 you might have had the same result. Some mixed cab combinations work well together, some don't, and there's no way to predict it. Identical cabs will always get along well. OTOH some cabs are crap to begin with, so using two is still crap, just more of it. [quote]You mean stacking the 2x10s on their narrow ends? Anyone ever done this and not worried a bit about how wobbly it looked?[/quote] Drivers should always be vertically arrayed. It might not have a conventional look, but what looks best and what sounds best seldom coincides. Manufacturers concentrate on creating what sells best, and that's what looks best.

[quote name='Big Mick' post='1012693' date='Nov 4 2010, 06:42 PM']Hmm, interesting observation Bill. Can you expand on the reasons for your advice (I'd like to know as if the driver is still useable, then a new one is a major expense). Cheers, Mick. [/quote]Building a well engineered cab is a lot of work. IMO it's a shame to get less out of a good cab than its capable of giving by using inferior drivers.

AFAIK the TNT uses a Blue Marvel driver, which is OK for a combo, but I wouldn't put it in anything else.

[quote name='4 Strings' post='1012207' date='Nov 4 2010, 11:53 AM']That seems huge to me, if one imagines the cone moving 32mm each way.[/quote]It doesn't. The voice coil diameter is 3 inches. Excursion is probably in the vicinity of 4 to 6mm.

[quote name='4 Strings' post='1012226' date='Nov 4 2010, 12:04 PM']Should I bother anyway?[/quote] No. There isn't enough difference in the response of the two cabs to justify it. All bass cabs are full range, quite different from better PA cabs that are designed to operate within distinct bandwidths.

[quote name='ThomBassmonkey' post='1011719' date='Nov 4 2010, 05:42 AM']All things being equal (in terms of sensitivity etc) and a 15" will produce more volume than 2 10". It's never that simple though. I prefer 10" speakers though, so it's a no brainer for me, I'd rather have the sound I preferred than a tiny bit more volume. [/quote]+1, and 'tiny bit' hits the nail on the head. Using a pair of tens versus one fifteen, with the same excursion and fed with the same power, the fifteen might go 1.5dB louder. That's inconsequential.

[quote name='JPJ' post='1011766' date='Nov 4 2010, 06:16 AM']Main stream equipment suppliers seem to ignore Hoffman's Iron Law Am I right in assuming that the Thump is compromised and is making up for it with sheer power (1000w 'rating')?[/quote] The Thump is compromised, and the 1000w rating is 'peak', not RMS. With an F3 of 50Hz it doesn't even qualify as a true subwoofer, that being the result of a cab that's too small to go both loud and low. Hoffman will not be denied. With a premium long excursion driver one can use high power to overcome the limitations of size. But the Thump isn't loaded with a premium long excursion driver, and 500 watts RMS isn't high power where subs are concerned. Not that it doesn't serve well enough considering its size and price, but it hardly lives up to its overblown advertising. To be fair, though, not much does.

[quote name='keeponehandloose' post='1011306' date='Nov 3 2010, 04:22 PM']A single 15 pushes more air than 2x10s ,as it has more surface area,so 2x10 + 1x15 should seem louder[/quote] Surface area is a two dimensional measurement. Drivers operate in three dimensions. The other comments by various posters all have some merit, but none are definitive as, to repeat, driver size alone is insufficient data. But if it was me I'd run a pair of 2x10s, the drivers vertically arrayed.

[quote name='xgsjx' post='1011274' date='Nov 3 2010, 03:53 PM']Been answered many times. 2 2x10 8 ohm cabs will be considerably louder & better quality than 1 4x10 4 ohm. Have a look in the Impedance sticky, especially the last couple of pages.[/quote]Assuming the same drivers, same cab volume per driver and same tuning two 8 ohm 2x10 will be identical in output to one 4 ohm 4x10. The only difference is dispersion. If the two 2x10s are vertically stacked they will have twice the dispersion angle as one 4x10. But the OP asked about one 2x10 plus one 1x15 compared to one 4x10. The answer is that one can't say, insufficient data. It would likely be close.

[quote name='4 Strings' post='1011103' date='Nov 3 2010, 01:26 PM']Sensitivity is not such an issue nowadays with power coming cheap, so this would seem a good compromise (and one of which I would love to take advantage but they are so expensive!) but do you get such a deep and powerful tone?[/quote]Power is cheap. Drivers that can make use of it, not so much. And that doesn't mean watt ratings, which are next to worthless. It has to do with excursion, and the usual sources do not use high excursion drivers.