alexclaber

The 'frequency response' specs quoted by 99% of cab manufacturers are essentially pointless. We put one of those vague ones on our site just to stop people writing off the cabs because they're not seeing the numbers they want to see and then the useful response specs are in the technical info bit. There is a serious risk that if you put those useful specs out front and centre then bassists (particularly those with a low B or lower) will assume that your cabs can't handle a bass whose lowest string is tuned to ~31Hz. With the Big Series cabs we focused on fantastic performance with lower tunings (F# below low B etc) and in the real world of loud gigs the cabs stomp all over some cabs that are designed specifically for low B by being tuned to 31Hz, because we've considered not just the fundamental frequency but the energy content when you play that note, the inherent highpass filtering in bass amps and power amps and the required tone to work in a mix at high SPL. Based on the speaker configuration and internal volume of the Schroeder 410L there's no way the -3dB point can be below 70Hz (and there'll be a hump above 100Hz which will make that F3 effectively higher) and by 40Hz it'll be at least 12dB down. I haven't had the time to accurately measure many other cabs (but, having spent enough time listening to ones with whose response plots I know, my ears are pretty reliable at detecting peaks, dips and roll-off points) but their response curves tends to be seriously far from the implied flat from 40Hz-20kHz response suggested by specs. (Courtest of OldogNewTrick on the fEarful forum) here's a load of plots from a Line6 modeller (so one would hope that these are fairly accurate representations of the following cabs - my ears certainly say so): '70s Ampeg sealed 8x10" Acoustic 360 (folded horn 18") SWR Goliath 1 (ported 4x10"+tweeter) Fender Dual Showman with JBL D140F (sealed 2x15") Mesa Boogie 2x15" Hiwatt 2x12" Sunn Coliseum 18"+12" Ampeg B15 Versatone Pan-O-Flex (crazy old biamped dual voice coil 1x12") EA CXL112 (transmission line coax 1x12")

I'm glad Bakithi Kumalo never listened to Jeff. Or Les Claypool for that matter...

Any accurately rated 500W amp will have almost as much headroom as an similarly accurately 900W amp! It's less than a 2:1 difference, which is less than 3dB. And when you figure in power compression the difference is even less. For differences in power to be truly significant you have to think in ratios of 3:1 or more. 400W difference is a lot if you're going from 200W to 600W (1:3) but almost nothing if you're going from 1200W to 1600W (3:4). When you're looking at these lightweight bass amps, the amp you like most will be the one that has the right feel for you, which will often be the one that reaches its limit in the way that you most like, and that too will be the amp that you deem loudest. Thus some will deem Markbass amps loudest, some Genz, some TC, etc... No-one's wrong but no-one's right either!

Andy, send me an email if you want some help with the amp choosing part - the key is matching all the parts of the signal chain together, from your hands to the speakers, to get the tone you want! Everyone's idea of thump/punch/clarity is different, hence the sound clips thing...

Once you start understanding T/S specs, even if it's via modelling software, things make a lot more sense! Big drivers suffer from the same box size problem as small drivers if you want bass extension, the parameter Vas describes how large the enclosure needs to be to get a given amount of extension. If you mess around with these parameters you'll see that changing Mms and Cms to lower Vas will result in lower sensitivity - sensitive, low, small, pick any two!

[quote name='andydye' post='1301195' date='Jul 12 2011, 03:54 PM']...and cab options appear to be... Bergantino AE112 300W, 40hz-18khz, 100db 1w m, 31lbs, £585 (Bass Direct) - can't get them new now though Aguilar GS112 300W, 42hz-16khz, 95db 1w m, 42lbs, £408 (Bass Gallery) Epifani UL 112 300W, 43hz-16khz, 100db 1w m, 32lbs, £475 (Bass Gallery) Genz Benz Neox-112T 300W, 45hz-18khz, 98db 1w m, 36lbs, £595 (Bass Gallery) Vanderkley 112EXT 300W, 45hz-16khz, 100db 1w m, 33lbs, £550 (Bass Gallery) Barefaced Midget T 300w, 37hz-22khz, 95db 1w m, 22lbs, £550 (Barefaced)[/quote] A few things to point out! The Midget T has a 3" voice coil which means it handles 400W thermally all day long whilst the other cabs have 2.5" voice coils so they're in the 250W area thermally. The Midget T has a stronger magnet so it has greater broadband sensitivity, so it produces greater loudness from a given wattage input, than all the other cabs. The Midget T can move more air than the other cabs because it has more Xmax and greater port area and will handle much more power in the lows (550W) without distortion. Thus two Midgets will produce as much output as three AE112s or UL112s or Neox112s or four GS112s. This ability is borne out by Midgets being used singly in loud rock bands, which is almost unheard of for 1x12" cabs. Unfortunately due to the vastly increased cost of neodymium we're currently applying a £40/woofer surcharge to cover some (nowhere near all!) of this cost increase.

Read the bit about volume displacement on there! Sd x Xmax. The problem with many small drivers (and indeed the problem with most cheap cabs regardless of cone diameter) is a lack of Xmax. I'm working on a single 8" at the moment that can move more air (and thus generate greater LF SPL) than most 15"s on the market! Try getting that out of the 8"s I've seen in past bass cabs and you'll have a dead speaker on your hands...

[quote name='dc2009' post='1300064' date='Jul 11 2011, 04:30 PM']I'm very good with understanding of waves/this type of thing though my knowledge of this particular area is pretty much nil, if you could point me towards some good links it'd be appreciated, technical ones aren't a bother either (I am meant to be an engineer after all).[/quote] I've written quite a bit on this, which can be found in the technical info and BGM articles sections of the Barefaced website. Regarding music/hi-fi shop technical expertise, I've yet to come across a single member of staff that really understands what they're talking about - that doesn't mean there aren't any out there but the fact is that audio and acoustics is rarely intuitive and so what seems obvious and passes into guitar shop folklore is usually wrong!

It's all too easy to spend all my time replying to emails when cabs need designing/building so although I read most of them almost instantly I tend to reply in bursts. Some replies take longer than others depending on how obvious the answer is! I'm planning to get one of our employees trained up but if you've been through the Barefaced sales process you'll know that it there's quite a bit of expertise required to match customer to product...

Unless something weird has happened and one of the cabs is wired with reversed polarity then a 4x10"+1x15" should be damned loud! You won't be able to truly use all 450W without things getting somewhat distorted because the 15" will complain due to over-excursion but even 200W driving a stack that size will be LOUD. Definitely a case of player error, but not Al, the players with those funny little guitars!

If they don't believe you then try to get some recordings, one where they're playing with the levels as you suggest, one with the levels as they like it - hearing is believing! Removing most of the damping from the kick and tuning a bit higher, particularly the resonant head will get more volume and a tone that often works better live, even if it isn't as thumpy and pretty on recordings. But I would say that as I have a particular penchant for bombastic 26" kick drums and have a fairly heavy right foot...

If you're losing the drummer then the band will end up sounding weedy and not very RAWK at all. Listen to any albums or live recordings where the guitars dominate and the drums are too quiet and it's always the same. If your guitarists want to sound like they're in an aggressively rocking punk band then they seriously need to turn down. If they don't then they should go any play acoustic music where there are no drums! And I bet if you can't hear the drums well I bet then the kick drum is particularly lost! Set the volume level off how loud the drummer can consistently play the kick. Any louder and you're just shooting yourself in the foot as the band will annoy the punters more but they'll feel the music less. Rant over!

Can the vocalists be heard at all?

[quote name='bassgurumonster' post='1297024' date='Jul 8 2011, 12:09 PM']Im a bit old school when it comes to cabs but the obc is rated at 600wts and the spc410 is rated at 1200 wts!! confused.com [/quote] 75W into the OBC410 will be about as loud/fat as 300W into the SP410.

[quote name='aldude' post='1295641' date='Jul 7 2011, 08:47 AM']When you daisy chain cabs, even though it looks like they're connected in series they are actually connected in parallel [/quote] Exactly! What looks like just one wire going between the cabs is actually two, so you're running one wire between the amp's and all the cabs' positive terminals, and another wire between the amp's and all the cabs' negative terminals, so: amp positive -> (cab 1 positive & cab 2 positive & cab 3 positive etc), amp negative -> (cab 1 negative & cab 2 negative & cab 3 negative etc) If you were connecting things up in series then you'd go: amp positive -> cab 1 positive, cab 1 negative -> cab 2 positive, cab 2 negative -> cab 3 positive, cab 3 negative -> amp negative So here you see that with the parallel approach you're applying the amp's full voltage (aka potential difference) across all three cabs. Whilst with the series approach you're only getting 1/3 of the voltage across each cab (with three cabs). In other words with parallel cabs voltage is the same across all three, whilst with series cabs current is the same through all three. (Ignoring the fact that resistance and impedance are actually different but things will get rather complicated if we have to start including phase, so this is a simplified explanation): Power = Voltage * Current Current = Voltage / Resistance Therefore Power = (Voltage * Voltage) / Resistance And also Voltage = SQRT (Power * Resistance). So if we have a 500W into 4 ohm amp. Max Voltage (i.e. when it's putting out 500W) = SQRT (500 * 4) = 44.7V So if you connect two 8 ohm cabs to this 500W @ 4 ohms amp, either daisy-chained or with one cab to one speaker out, the other cab to the other speaker out, so they're in parallel. Power per cab = (44.7 * 44.7)/8 = 250W If you make up a special series lead and connect two 8 ohm cabs in series then the voltage across each cab is halved: Power per cab = (22.35 * 22.35)/8 = 62W Understanding (solidstate, not valve) amps gets a lot easier when you start thinking about the amp putting out volts, not watts. It is a voltage amplifier - it amplifies the current too but only in response to the load, and that's why there's a minimum impedance - because once the impedance drops too low then the amplifier can't put out enough current to keep up.

I think slap should only be allowed if it's done vintage Larry Graham style. Old strings, no/minimal tweeterage, treble rolled off. Thumpin' and pluckin' as he calls it, none of that twangy annoyance!

I shall be there, unless my one window of opportunity for a holiday is over that weekend! Will bring as large a variety of Barefaced cabs as fits in the car and the trusty RIM Custom 5...

I love the bass sounds on that album! I think a cascaded solidstatey distortion into a tubey overdrive could be the answer - so in my case I'd run an MXR Blowtorch (running only gentle fuzz and a fair bit of clean sound) through a Fulltone BassDrive (again fairly mild overdrive). A lot of it's about how you attack with the right hand and mute with the left though!

[quote name='Mr. Foxen' post='1292657' date='Jul 4 2011, 08:15 PM']So why didn't they do that before? Was it uneconomic?[/quote] Technological progress really. Hardly anyone's been doing R&D on ferrite magnet motors for the last 5-10 years, so the neodymium stuff is a generation or two ahead. But if neo is impractical due to cost/availability then the R&D focus will shift.

I think the very long term (i.e. decades) supply situation may be ok due to the sudden increase in prospecting etc. I don't expect the price of neodymium to ever go back to where it was as it's pretty nasty stuff to refine and one of the reasons (as I've only just discovered!) that the price came down in the first place (about a decade ago) was thanks to China ignoring environmental and health and safety issues when producing it. Now they're changing their stance and expecting other countries to deal with the challenges of rare earth metal mining and refining themselves - and in the meantime they're making lots of money by restricting exports whilst everyone else gets up to speed. Re-opening the handful of existing rare earth facilities outside China will take a year or two and output will only cover 'essential' needs (i.e. military!) Opening new mines and refineries on land will take longer still. Developing new underwater mining techniques will be a huge technological challenge and will take many many years before they have significant production capacity. Having discussed this matter with various large loudspeaker manufacturers the feeling is that with a bit of cunning you can do with ferrite what you can do with neodymium, just with extra weight. And the loudspeaker industry consumes less than 1% of all the world's neodymium production so even the biggest manufacturers are insignificant customers compared to those in the automobile, rail and energy industries, and the upsides of neodymium for their products are much more important (greater efficiency being the main one) than the upsides in loudspeaker products. Loudspeakers are thus pretty much bottom of the pecking order on both economical and practical grounds. This is what we OEM Eminence customers received a few weeks ago: [url="http://www.acmebass.com/seriesiii/20110615NeoCustomerUpdate.pdf"]http://www.acmebass.com/seriesiii/20110615...tomerUpdate.pdf[/url] As of last week I heard that new magnet orders are being taken as the quote has been revised but there has been no official announcement of this or of the revised annual quantity, and the prices are continuing to change constantly...

[quote name='Bankai' post='1291939' date='Jul 4 2011, 11:13 AM']But surely the same wattage going into 2 cabs will be louder than 1 due to moving more air?[/quote] It would normally. But it's either 500W into a cab that's 98dB sensitivity (@ 100Hz) or 250W into a 98dB sensitivity cab plus 250W into a 89dB sensitivity cab. 98dB + 500W = 125dB (98dB + 250W = 122dB) + (89dB + 250W = 113dB) = ~123dB That's in the lows. Who knows what is going on higher up because isobaric designs are normally only used for bass (i.e. true woofer & subwoofer) purposes!

I'll be interested to hear the results of that! I suspect that using the SP212 and Compact together will be quieter than the Compact on its own. If it isn't then there's probably something funny going on with the impedance switch.

We recently started putting dual speakons on all our 8 ohm cabs because of this. Previously second speakons were an optional extra for those buying their second Barefaced cab. However it's incredibly easy to turn two speakon leads into a single Y-lead with nothing but a screwdriver and 10 minutes of your time.

There is no such thing as 'exact ohmage'. All bass cabs have an impedance curve which is very far from being the flat line at 4 or 8 ohms that specs would suggest. If anyone's interested I can probably get a whole bunch of plots next week and we can see if there's anything special about the RS cabs. Right now I think Stevie's 95% likely to be correct, though from having had a hand inside them and considered the weight vs cab construction I suspect Re could be a little higher than on many premium cabs due to the small magnets.