Bill Fitzmaurice

[quote name='Chopthebass' post='58952' date='Sep 11 2007, 03:27 PM']But Mackie in the UK told me that won't be suitable for bass guitar, but they couldn't back it up with a technical reason![/quote]That's because they're clueless pencil pushers, not engineers. Assuming it's properly constructed it should work very well, I can't think of a commercial electric bass cab that would work as well. But it will sound quite different than what you're used to, and that may or may not be to your liking, so try one before you buy one.

[quote name='Russ' post='57273' date='Sep 7 2007, 09:45 PM']I've been toying with the idea of putting together a more "hi-fi" kind of bass amp, using either one or two PA speakers, a power amp and a preamp of some description. Basically, a system that will have a wide, full frequency response, without the colouring that bass-specific cabs add to the sound.[/quote] IMO the best bass cabs and the best PA cabs are interchangeable, because they share the same requirements: wide bandwidth, high output uncolored response. The vast majority of bass cabs don't fit that description, being in reality modified guitar cabs. For that matter, until the '70s most bass cabs [i]were [/i]guitar cabs, sharing the same drivers and design. Bass players just used more of them to get the same output levels. With the advent of bass specific drivers and T/S cab tuning in the '70s bass cabs became more bass friendly, but the basic design has remained in the mold of guitar cabs, as has the sound, with restricted bandwidth and a lot of coloration. For all intents and purposes mainstream bass cab technology has not advanced in the last 30 years. If one looks at a 1970s bass cab and the current crop they look the same, and for the most part sound the same, the only improvements being those resulting from better drivers. The PA industry never stagnated, with improvements coming at a regular rate. Today's concert bass sound is defined by the PA, not the backline, and the bassplayer who wants that same tone on stage has to look to PA gear or bass gear designed according to PA standards to get it.

[quote name='BOD2' post='57775' date='Sep 9 2007, 10:52 AM']To that end, as mr gig suggests, try to get the monitors as close to the ears of those using them as is practical as this means you can turn them down more.[/quote]Which brings up another point: each player needs their own monitor. One can't place them adequately close when they must be shared.

[quote name='BOD2' post='57738' date='Sep 9 2007, 09:39 AM']A feedback destroyer shouldn't be necessary if you follow the above steps but is there as a last resort.[/quote] Even if you have a 31 band graphic EQ it does you little good taming feedback if you don't know which frequencies are the offenders. Also, 31 band EQs have wide bandwidth 1/3 octave filters, so they remove too much information. Feedback destroyers use narrow bandwidth filters that kill the feedback without destroying intelligibility, and they find the offending frequencies on their own. [quote]Is there anything else I should be doing? EQ'ing?[/quote]Absolutely, you can't run monitors without their own dedicated EQ. If you don't have one you should purchase an EQ that has a feedback destroyer built in.

[quote name='Sibob' post='52094' date='Aug 28 2007, 08:16 PM']RSH, you're the first guy i know who has said they can't get a decent sounding E from a 350watt 2x10 Ampeg combo Si[/quote] That's very much a matter of how loud one plays. Most of the power requirement of an open E will fall at the second harmonic, about 82 Hz, and that's right in the range where the Ampeg cab is displacement limited to only about 60 watts before exceeding xmax and distorting heavily. I can see how anyone playing at even moderately high levels would be wanting for more.

[quote name='alexclaber' post='50179' date='Aug 24 2007, 09:51 AM']You'd be far better served by learning about pro sound and audio engineering. A huge amount of the audiophile market is driven by snake oil sellers and psychoacoustics, supported by the magazines whose revenue stream is driven by the advertisers of said snake oil.[/quote] Quite right. If the esteemed Mr P.T. Barnum were alive today ("[i]No one ever lost a buck overestimating the intelligence of the average person."[/i]) he would be selling $1,000 per foot cables and $200 power conditioners. Most power conditioners offer no more protection or 'conditioning' than is already present within your amp and other gear.

[quote name='OutToPlayJazz' post='47298' date='Aug 19 2007, 05:32 AM']You all know the routine - Leave your Fender plugged in & without touching it, the bad earth demons hit until you touch the strings & it all goes quiet![/quote] That's as it's supposed to be, and is the reason why the bridge/strings are grounded. It's an unavoidable consequence of high impedance pickups. Some are better/worse than others, but none are immune.

[quote name='d-basser' post='47955' date='Aug 20 2007, 03:58 PM']think this is the wrong section mate anyhoo I am 5'8''/9'' ish Look for something smallish body (ie not fender) I like Peavey. Shorter scale may also help though I play 34" and 35". Adjust strap/ posture, the positioning could bet he problem rather than the bass. I found raising the bass quite high helped (so when i stood it was the same as sitting) hope this helps, you need to specify the discomfort really[/quote]I'm 6 foot 250 pounds and I prefer a 30" scale. Both Fender and Gibson make some with 30 inch scale boards.

[quote name='ShergoldSnickers' post='46545' date='Aug 16 2007, 01:05 PM']On their own, wattage values are almost meaningless. It depends which speakers the amp is driving. Then there is the question of how efficiently the speakers convert the amp output into sound. This is probably a bit of a neglected area. Most look at the amp first and the speakers second. But, buy some really efficient speakers and you can then afford to look at a less powerful amp. You'll get the same sound power level (SWL) with fewer watts, lighter weight and less cost.[/quote] +1. I personally am now running one channel of a Superfly and find it's more than adequate, but I have high sensitivity speakers. It makes a difference with tubes too, as the natural compression of a tube amp can easily make it sound as loud as an uncompressed signal with 200 watts SS. While I'd not say that 50 watts tube is enough with off the shelf speakers, in the case of high sensitivity speakers it can even be more than enough.

[quote name='stanton119' post='44626' date='Aug 12 2007, 05:25 PM']Even when I used to have bass direct to amp. If I touched the strings and the radiator I would get a small shock as you have described.[/quote] This is where a GFCI outlet protects you. Your strings are grounded, but not perfectly so, as there is resistance in all of that wire that connects your bass to your amp, and then your amp to the outlet, and finally the outlet to the street mains panel. There can be quite a bit of resistance in that wire, while alternate paths to ground, such as heating systems and water pipes, or God forbid standing on damp earth or concrete floors with no shoes on, may have considerably less resistance. Electricity always takes the path of least resistance, and in cases such as described that path is you. GFCI outlets sense when current is flowing through pathways other than those intended and shut it off.

[quote name='stanton119' post='43891' date='Aug 10 2007, 12:50 PM']I think I may have sorted it out: Using a ground loop isolator i tried connecting item by item every configuration possible, measure the PD each time. The best solution I have found is by placing the ground loop isolator between the mixer and the laptop. There was then not shocks between the laptop case and the cable. However, know there are now sparks between the cable for the bass and the laptop case. Would it help to place ground loop isolators between everything?[/quote] Isolators aren't fixing the problem, they're just hiding the symptoms. All of your devices should be grounded together at one single ground point, say a power strip, while any peripherals such as cable or internet connections that are remotely grounded should be transformer isolated.

[quote name='stanton119' post='43506' date='Aug 9 2007, 05:07 PM']What can I do to eliminate this???[/quote] Is your TV also connected to cable? The voltage you're reading indicates more than one ground path is present. Read this: [url="http://www.rane.com/note110.html"]http://www.rane.com/note110.html[/url]

This is required reading for anyone using electric instruments and sound gear: [url="http://www.rane.com/note110.html"]http://www.rane.com/note110.html[/url]

[quote name='stanton119' post='42518' date='Aug 7 2007, 11:16 AM']connected to separate mains supply connected to different mains supply and ethernet[/quote] That's your problem. Don't do that.

[quote name='Kurt' post='42390' date='Aug 7 2007, 06:34 AM']I'm not sure if the whine will be an issue as it doesn't increase as the master volume is increased, although it is annoying at practice volume levels. I'll post back when I get the new one and let y'all know how it pans out.[/quote] Mine has 60 Hz hum in both channels, not loud enough to be a problem and no worse than any other $300 amp, but at the original price it would have been unacceptable. Mine also has whine in one power amp. It is very high frequency, and turning the tweeter off gets rid of it. I suspect owners of cabs without tweeters would never notice it. The source is undoubtably a defect in the low pass filtering on that power amp, and may be a basic design flaw. If all those who do have whining amps have tweeters and all those who's amps don't whine also don't have tweeters it would explain why not everyone has a problem.

[quote name='peted' post='42176' date='Aug 6 2007, 04:08 PM'] Is this what you were talking about BFM? I'm going to make it my mission to make this rig in a store to see what it sounds like.[/quote]That's it as far as the soundfield height is concerned. That doesn't mean you'll necessary care for the tone of any specific pair of 2x10s, but it's on the right track. Find the 2x10s that give you the tone you're after and you're there.

[quote name='alexclaber' post='40640' date='Aug 2 2007, 04:08 PM']Never owned one but I can see the appeal. I would never pay the obscene prices Ampeg charge for what is essentially eight cheap 10" woofers in a simple box. This is near as dammit the speaker they use: [url="http://www.bluearan.co.uk/menu/index.php?id=EMIALPHA10A&product=Eminence_Alpha_10_150W_10!dquote!_Driver&browsemode=category"]http://www.bluearan.co.uk/menu/index.php?i...semode=category[/url] Keep an eye out for a well used one, or consider building your own - make it from 1/2" ply and make it a 6x10" instead of an 8x10" and you'll save yourself a ton of weight but get the same tone and only fractionally less output. Sealed cabs tend to roll off at a higher frequency - usually around 150Hz and then the response gradually decreases eventually dropping at 12dB/octave lower down. Ported cabs stay flatter lower and then drop at 24dB/octave - but many have a mid-bass hump tuned in around 100Hz to fake sufficient bottom. Alex[/quote] Mostly spot on. While more expensive drivers tend not to work so well in sealed cabs, the Alpha 10 has sealed friendly specs, and typically is pretty flat to 80 Hz; in an SVT the -3dB (half-power) point is 58Hz. The main source of the SVT 'sound' isn't the drivers or the sealed cab, it's the height of the radiating plane. One can get the same effect from a pair of 2x10s stacked vertically, sans cost, hernia and transportation issues.

[quote name='Ba55me15ter' post='37898' date='Jul 27 2007, 12:23 PM']Although don't get too set on the biamping idea. I tried it (with a 'suitable-for biamping' advertised pair of cabs) and didn't like it. Sounds much better full range into both.[/quote] That's usually the case with cabs that are 'suitable for' rather than 'optimized for'. True subs and tops don't work well at all when not crossed over, either passively or electronically.

[quote name='Hamster' post='19589' date='Jun 18 2007, 08:11 AM']I bet you half a mars bar it's a fried output transformer[/quote] On a SS amp?

[quote name='Hamster' post='37369' date='Jul 26 2007, 10:28 AM']Who was it said American's don't have a sense of humour? [/quote] Benny Hill?

[b]Acme's #1 Endorser:[/b]

[quote name='Bigwan' post='36552' date='Jul 24 2007, 03:09 PM']Hi Bill. I was hoping you'd see this post. If I were to build one of your cabs and disregarding size (within reason!) which of your omni series cabs would be the 'flatest'. From a VERY brief look at your website I'd assume it was the omni 15 full range cab - would an 8 ohm Kappa 15LF eminence driver be suitable for this cab? If size were a more pressing concern, would an omni 12 be suitable for what I'm looking for? Cheers Ian[/quote] The O15 is the flattest to the lower reaches, but most will find that the LF extension and power of the O12 most adequate. When it comes to modeling it's the midrange that's critical, and that's where commercial cabs are the most dodgy. The Kappa 15LF is fine for the O15LF. 20" wide versions of both these Omnis will be available soon, so if you fancy a tallboy rather than the present versions wait until you see the TallBoy versions offered.

To get truly flat response a cab must either have a dedicated midrange driver or some very sophisticated engineering, if not both, and you will have a hard time finding either of those qualities in an inexpensive cab. As for size, good bass response at high levels requires a reasonably large cabinet, though not necessarily a heavy one. But again, the engineering required to build a cab that's large, lightweight and still inert won't be found in an inexpensive product.

The LA would be OK if it sold in the $500-$800 range. However, Bose has an advertising budget somewhat larger than the GNP of most countries, and paying that nut has to come from somewhere other than the pockets of the shareholders.

[quote name='paul, the' post='33801' date='Jul 18 2007, 02:07 PM']Any big box makers that aren't crazy expensive?[/quote] I can't say, the last time I bought a cab it was 1965, and to say the least I'm not in the market to buy another within this lifetime. At any rate, the single easiest way to improve on the performance of most cabs would be to simply make them bigger, and in the grand scheme of things it's also the least expensive way to make them better. But the actual cost of making an item is seldom the main determining factor in what it sells for. Perceived value is.