Bill Fitzmaurice

[quote name='machinehead' post='901507' date='Jul 21 2010, 07:40 PM']Show me how the magnet material can be heard differently from another magnet material. Frank[/quote]It can't. The same argument was proffered when AlNiCo replaced field coils, and then when ceramic replaced AlNiCo. And it's just as fallacious now. Flux is flux.

[quote name='umph' post='899112' date='Jul 19 2010, 11:33 AM']thats your problem there the bright box isn't really gonna keep up with the ampeg is it in terms of output![/quote] It's more than just a sensitivity issue. Assuming that it only uses a high pass filter a goodly portion of the frequencies that should be diverted away from the woofers and into the mids are still going to the woofers. That very much fouls up the program right there, and as I recall Trace had the drivers horizontally arrayed, furthering the damage. Using dedicated mid drivers is a very good idea, but if not properly implemented any good idea can be all for naught.

[quote name='ianSB' post='898288' date='Jul 18 2010, 02:02 PM']im using it with a 610 hlf[/quote]A 610HLF is adequate to say the least, so if you're not able to compete with the drummer and guitar'd players they're too damn loud.

[quote name='ianSB' post='898234' date='Jul 18 2010, 12:53 PM']my ampeg svt450 seems to be underpowered :S its not competing at all with the guitars and drummer and its pretty much cranked i was just wondering what could be the problem[/quote] Probably not enough speakers to make use of that power.

[quote name='bobpalt' post='897894' date='Jul 18 2010, 06:30 AM']he said no, that wasnt the problem, it was that "blasted low/mid sound that all neodymium speakers have"... I have to admit I had absolutely no idea what he was talking about![/quote] That makes two of you. He had absolutely no idea what he was talking about either. A knowledgeable sound man would know which frequencies were too much, and would simply pull them down in the mix.

[quote name='obi 2 kenobi' post='891103' date='Jul 10 2010, 04:47 AM']hi, probably dumb question. Just picked up 2 MarkBass Traveler Cabs (2 x 10). Each cab has one speakon and 2 1/4 inch jacks. Question : why 2 1/4 inch jacks ? What's the difference between them (if any) ? Thx[/quote]One 1/4" so you can run it with a 1/4" cable from an amp with no Speakon out, one 1/4" to parallel another cab with a 1/4" input. But you should be using the Speakon anyway. Why not two Speakons on each cab? It saved MarkBass two quid.

[quote name='Al Heeley' post='889401' date='Jul 8 2010, 07:01 AM']I asked in the Hartke subforum about how to rewire the 410 cab as a 4ohm to get the max push out of the amp and was told it could not be done.[/quote]Nor is it generally worthwhile anyway. Few cabs will take more than half their thermal power rating before exceeding excursion limits. Even were that not an issue you'd only get 2dB additional output from a 4 ohm versus 8 ohm cab. That's audible, but just.

[quote name='bigjohn' post='888848' date='Jul 7 2010, 02:36 PM']Indeed. If you we're going to run them parallel I'd have them rewired to give them greater impedance. You won't notice that you're not drawing "the full power" from the amp. Or have them rewired so you can run them in series.[/quote] The jacks on the back of the amp are parallel wired, as are the paired jacks on the cabs. It doesn't matter whether you use both jacks on the amp or run one cable to one cab and daisy chain the second cab from the first, it's still parallel wiring. You only get series wiring when you use a specially made series wiring harness.

[quote name='Al Heeley' post='888648' date='Jul 7 2010, 11:54 AM']Peavey Tour 450 head & 2 hartke cabs: Does it make any difference if I wire each cab from the two separate outputs on the amp, or daisy chain them from amp to cab1, then cab1 to cab 2? Is there a best method?[/quote]Electrically both methods are identical, a parallel load. The only potential advantage to running the cables each separately to the amp is then the current flow and cable resistance loss is divided between them. That's only an advantage if the cables are shy on current capability and have high DCR from being under gauged.

[quote name='thinman' post='878792' date='Jun 27 2010, 08:22 AM']I was worried about phantom power with my amp too. OBBM, who posts on here, suggested the following that works well and is about as cheap as you can get: On a XLR pins 2 and 3 are both at +48v, i.e. common, relative to pin 1 ground. If you simply disconnect pin 1 there's no circuit for the phantom voltage any more (and it also cures any earth loop issues). The signal out is carried by pins 2 and 3. I made a short tail lead with pin 1 disconnected and it does the trick nicely.[/quote] That might lead to grounding issues with some boards. The better option is to wire 1uF 50v tantalum capacitors in series with the pin 2&3 leads, and they're so small that they'll fit inside an XLR shell.

[quote name='fatback' post='873553' date='Jun 21 2010, 10:22 AM']Bumping in hope of an answer to this interesting one... [/quote] Get a couple of inch high rubber cabinet feet, screw them to the rear of the cab top to act as stops to keep the amp from sliding off.

[quote name='Bilbo' post='871148' date='Jun 18 2010, 04:29 PM']Most desks let you turn the phantom power off....... at least that's what I thought.[/quote] It's usually on or off globally for all channels, unless it's a high end desk. A transformer or capacitive coupled DI isn't bothered by phantom power, but some DIs inexplicably aren't one or the other, inexplicably as the cost of isolation caps is a few pence. Check with the amp manufacturer.

Tilt it back. Lifting it on a table creates a loss of boundary reinforcement in the midbass. In a boomy room you may find that beneficial, but otherwise tilting it back to put the driver centers aiming at your ears is better.

[quote name='Matty' post='866386' date='Jun 13 2010, 03:37 PM']I've always imagined them to sound tinny, perhaps swayed by the apearance?[/quote]Absolutely swayed by the appearance. The only instance where a metal cone will sound different than a paper cone is when you hit them with a stick. There's no particular advantage or disadvantage to aluminum cones except as marketing tools.

Add a four inch duct to the port.

[quote name='Phil Starr' post='857859' date='Jun 4 2010, 07:10 PM']There's a problem with most 4ohm drivers as well. they are usually made by just changing the voice coil for a shorter one which ...reduces excursion (Xmax)[/quote]Not if they do it the right way, by reducing the number of windings on the same former. But your point is valid, not every driver manufacturer does things the right way, and you must pay attention to all the driver specs, not just impedance.

[quote name='cameltoe' post='857651' date='Jun 4 2010, 03:29 PM']So with the RMS output almost doubled from going 8ohm to 4ohm, through a speaker that can handle the power, I'd really see no extra (real world) volume?[/quote]Not enough to make it a worthwhile venture. What would work if you must stay as small as possible is a high powered compact amp, at least 300 watts into 8 ohms, and a fifteen with high sensitivity and long excursion, such as an Eminence 3015. With a low powered amp the only way to get high output is with at least two drivers.

[quote name='cameltoe' post='857309' date='Jun 4 2010, 09:46 AM']However, knowing absolutely nothing about amps, I wondered if it was possible to get the full 150w from my Trace WITHOUT adding a cab? Could I, for instance, swap the 8 ohm driver for the appropriate 4 ohm driver to acheive max volume?[/quote] Full power is moot; the difference between what you might get with a 4 ohm driver versus 8 ohm is 2dB, and that's best case. Adding a second identical speaker gets you 6dB, which should do the trick.

[quote name='Randy_Marsh' post='849048' date='May 26 2010, 06:54 PM']I'm looking at a Hartke Cab for sale on here. It's rated 150watts RMS at 8ohms and i was wondering if i could increase the power and what it would involve, as i was hoping to get a cab with a bit more kick...[/quote] Only by replacing the drivers. Just buy a better cab.

They're parallel jacks, either can be used as input or output.

[quote name='Mr. Foxen' post='839089' date='May 16 2010, 01:37 PM']Is this mostly for when you are cramming loads of power into it? I have noticed old cabs have small ports, guessing its because the 2 15s are for sensitivity for lower powered valve amps, and just didn't take those sort of power levels.[/quote]If you go back 20 years or more when drivers with 2mm or less excursion limits were common, limiting them to 20 watts before going non-linear, then yes, you could get away with smaller ports. I wouldn't call 100 watts per driver loads of power, and most B-Ws will take that. If given that much the OP would get chuffing big time.

[quote name='umph' post='839036' date='May 16 2010, 12:33 PM']did you just stick a random port in or did you tune it properly to the drivers? Nice work by the way[/quote] +1. It may be OK tuning wise, but it's far too small and will chuff at high levels. Two ports with the proper duct length will work much better; minimum recommend diameter with fifteens is 6 inches [i]per driver[/i]. While at it, the cab could use panel to panel bracing fore to aft, side to side and top to bottom. Doing so with even single 1 inch wide braces will quadruple the panel stiffness.

[quote name='OldGit' post='836840' date='May 14 2010, 03:42 AM']Can anyone identify exactly which models they are? Head and Cab. It just says "Bassman Amp" on the head.[/quote] [url="http://www.ampwares.com/"]http://www.ampwares.com/[/url]

[quote name='Ancient Mariner' post='834199' date='May 11 2010, 08:32 AM']Resistance and impedance are not the same thing, and what you are measuring is resistance. Impedance varies according to, among other things, the frequency of the signal sent through the speaker.[/quote] +1. OP, read this: [url="http://wiki.basschat.co.uk/info:amps:impedance_and_wattage"]http://wiki.basschat.co.uk/info:amps:impedance_and_wattage[/url]

[quote name='Mr.T' post='828812' date='May 5 2010, 01:55 PM']Does that mean it's Ok for me to think that my new cabs sound good? [/quote] Some of the fave rigs of all time are Ampeg flip-tops, B12s, B15s, etc. They have one of the worst responses imaginable, with a huge midbass response hump and no real low end. That doesn't mean they don't subjectively sound good.