alexclaber

[quote name='LawrenceH' timestamp='1354876720' post='1891446']Which is TOTALLY irrelevant when you're looking at feeding a single speaker from a max of 250 watts with a crest factor of 10dB and you still have headroom, which is exactly my point. I think you are stretching that point for the sake of promoting your product here which isn't like you. We both know the advantages of drivers with more power handling, but also that the extra doesn't come at zero cost and that the performance benefits are irrelevant if you have a good driver working within its limitations. I don't think you need to worry that people will suddenly stop seeing the advantages of your cabs, they're very good and the price is still keen compared to other offerings. For me, the main gains offered by the long excursion neo drivers and modern amps is the ability to get to performance volume from a far smaller and lighter footprint. But 2 12s even in old money is enough for a lot of situations until you start with the smiley EQing. Then the problem becomes not the rig, but the person using it. Big bottom is nice but tonal perception is in the midrange, where extra volume is very cheap. I'm sure you'd agree that many cheap cabs are/were let down by lack of midrange clarity, and midrange performance is very important in your product line.[/quote] I'm not trying to push my products, I'm just trying to clarify the truths. One of the reasons that many cabs suffer with poor midrange clarity and punch is because they're not running clean and linear in the lows. In my opinion the OP should buy that used MBE212, get on with playing bass and stop thinking about amplification until it becomes a limiting factor. I've been working on a whole load of new designs over the last year and one thing which has become shockingly clear is how big an issue power compression is, in both of its forms, and that's shown quite why the Super Twelve is perceived as being so loud - it isn't amazingly sensitive, it just complies with Hoffman's Iron Law, but it stays linear to much higher SPL than most similar sized cabs, hence it's actual sensitivity when you need high sensitivity (i.e. playing LOUD) is higher when it counts. Have you seen what happens to the power demands and crest factor when a bassist wants a deeper fatter sound? [quote name='LawrenceH' timestamp='1354876720' post='1891446']Of course, but for a bigger gig where that kind of performance matters most, significant cab output low down is a problem, not a solution, from the point of view of FoH for reasons of both overall control and interference cancellation with subs. Again you know all this but are choosing to highlight only the advantages when every solution is in fact a compromise. The weak fundamental/first harmonics from sealed cabs are a blessing for mix engineers![/quote] I believe the ability of a cab to produce significant output low down is a very very important thing for bass guitar - education is key to using that output wisely (and our website is full of stuff about that) but a cab that can produce big clean lows will be much less problematic for FOH than a cab which can't and thus is messing up the stage and FOH sound with layers of mid-bass distortion and woolly midrange. In small venues it's a good thing to have multiple distributed low frequencies sources because you more evenly excite all the room modes, so having LF from the subs and the backline (assuming it's good LF from the backline) is beneficial. In large venues the output from the subs is likely to be so high that the effect from the backline LF is relatively insignificant. In mid-sized venues it depends but it's rarely as bad a thing as you make out. In small venues with smaller PAs it's a very good thing to have a bass rig which can carry the bottom for the house so that the PA can work less hard and produce a nice clean bottom for the kick. From a business perspective we are playing the long game - do the right thing, be true to the values and produce the best possible products and be completely honest about what they can do. Zero BS. I believe we'll make more money in the long term by behaving the right way because people will rightfully trust us and our products. It would easy to twist the science to big us up, it would be easy to make the products the market wants rather than what the market needs, but I don't believe in doing that. In the end I believe that doing the right thing will be the best thing for all concerned.

Get Paddy's cab (4 ohm is less than ideal because you won't be able to add a second and it won't be able to handle the extra power but it doesn't matter because if, in the the future, you find it isn't loud enough or has a less than ideal tone, you'll be able to upgrade with little or no depreciation cost)!

[quote name='LawrenceH' timestamp='1354815854' post='1890817']Haha, well that's fair but a semantic quibble We both know full well what I meant in the context of the OP looking for a cheap but acceptable cab for a 500w head and for 'maximum performance' by your definition it's not really necessary to spend a lot of money if you don't need to go loud.[/quote] Lawrence, I agree that the OP doesn't need one of our cabs, and I wouldn't have said anything if I thought it was clear that your point was only related to this specific context. The internet has massive opportunities for the spreading of misinformation and all I'm doing is trying to clarify what the real truth is. My points were exactly what I wrote: If you study power compression (both thermal and mechanical) you will see that it is a HUGE deal. Cabs become mechanically non-linear well before they exceed Xmax. Cabs become thermally non-linear well before they reach their thermal power handling limits. With like for like 1W sensitivity, cabs with greater mechanical and thermal power handling will be louder with 50W, 100W, 200W etc than cabs with less of either form of power handling. [quote name='LawrenceH' timestamp='1354815854' post='1890817']With enough power your cabs are capable of going WELL beyond volumes that people use at most gigs...[/quote] That very much depends on the bassist and the band and the gig. You could have two different bassists with the same band at the same venue and one could easily need 6dB more output than the other if his tonal preferences are skewed towards the lows. That requires a cab to move four times as much air and with power compression considered you're looking at needing maybe ten times as much power from your amp. [quote name='LawrenceH' timestamp='1354815854' post='1890817']The flip-side to your point about [i]larger[/i] voice-coil diameter, is of course that the [i]longe[/i]r voicecoils of high-excursion drivers are less efficient - the Kappalite HOs are very loud but could be made even more so by sacrificing excursion and power handling, and of course the broadband sensitivity of the LF is much lower. The older, smaller VC diam B&C 12HPL64 is similar in sensitivity to the HO for that reason and sounds very nice indeed - just won't go as loud.[/quote] The 12HPL64 only has similar sensitivity at 1W. Turn up to 100W and you're looking at around 3dB less sensitivity as the thermal and mechanical power handling are both about half as much as the 3012HO. And it won't handle much more than that without grumbling. If you're not gigging much or at all yet, then I can totally see the sense in buying a nice head first - especially if you're into home recording and want a nice preamp to DI through. If you're gigging and frustrated with your tone/loudness then it almost always makes sense to sort out the speakers first, as they represent the biggest gains in the live environment. Again, it's all about context!

[quote name='LawrenceH' timestamp='1354811431' post='1890730']Speakers like the Barefaced are just overpowered for this application anyway... ...how much power you actually need to get the most out of a high-excursion high-power cab. For maximum performance from a Barefaced S12, for example, I'd look at a decent PA amp (with built-in HPF like most decent amps have) capable of bridging down to 4 ohms with true 2000 watts output. It would be louder than I'd ever need though. [/quote] You don't need much power at all, you just need more power the louder you want to play. 'Maximum performance' is basically getting the SPL and tone you need for your gigs - if you don't need to be very loud then you don't need lots of power. Cabs with larger voice coils and higher excursion are louder than cabs with smaller volce coils and lower excursion of equal 1W sensitivity when both are driven with a mere 100W amp, because they maintain more of their 1W sensitivity through reduced voice coil heating and greater motor linearity. Use more power and the difference becomes even more obvious but that doesn't mean it isn't still there at lower SPL. I'd have expected better from you Lawrence than referring to a passive loudspeaker as 'overpowered'!

[quote name='4 Strings' timestamp='1354612173' post='1887916']I think Alex did in the past, probably too many going through to be able to do that now, easier to link to a signal for home 'Hellatoning'.[/quote] Yes we did. We're considering building a speaker storage / breaking-in / quality testing system, so we have a wall of shelving full of woofers half with polariity, half with polarity the other way, so we can run them in before they're put in the cabs - just need the time to design and build it. We wouldn't be considering this if it didn't make a difference sonically! [quote name='4 Strings' timestamp='1354612173' post='1887916']I'm suspect the effect of loosening is different with different speaker construction/size etc. Perhaps the foam surrounds are less needing a loosen. (They certainly become loose after 10 years or so when the foam begins it's conversion to dust!).[/quote] Yes, the suspension type makes a huge difference - a woofer with polymer / rubber/ foam surround and low stiffness spider will barely change in low frequency response whilst a woofer with a corrugated doped fabric surround and heavy duty stiff spider (or two or three spiders!) will change a lot. Also a woofer with a very stiff cone will barely change in the upper frequencies whilst a woofer whose cone is designed to flex will change through the midrange and treble. My Acme woofers sounded worse when they got worn out - a combination of cone creasing making them distort more easily but also the suspension having become floppy from being driven too far beyond Xmax too often, so they got boomier in the lows.

Stevie, I know all about the break-in rubbish used in the hi-fi industry to foist poor products on unsuspecting 'audiophiles' through the power of expectation bias, listener conditioning and placebo effects and this is absolutely nothing like that. I can only assume that the woofer you tested had already been used and therefore wasn't fresh or that your test procedure was flawed. You don't design a loudspeaker around a fresh unused example, you do it around one has been 'pre-conditioned'. If the designer knows what they're doing then one would hope that a driver which meets specs for the enclosure design would have better low frequency response than a new one whose specs are some way off. Furthermore the midrange and treble response in the non-pistonic region are affected by the suspension characteristics, just as changing the nut, fret and bridge materials change how your bass strings sound by changing the damping characteristics at the anchor points. Driver parameters also change at high SPL due to voice coil heating and motor non-linearity. It's a huge issue which I've been obsessing about for a long time. However, once voice coils are hot you're playing very loud and there are so many issues with the human ear alone at this SPL that you'd have to know what to expect to hear to realise it's going on. One reason I'm convinced that our Super Twelves (or Midget + Compact stack) are proving so popular is that the high sensitivity and large voice coils mean much less temperature rise in the voice coil, and thus better bass response (less boom, more depth) and less chance of clipping (because your amp can deliver more power to a cooler voice coil).

[quote name='stevie' timestamp='1354207585' post='1883657']I'm sorry, but running your speakers in is a completely pointless exercise. It's an audio myth. Your speaker is not a car engine. Sure, you'll soften up the suspension of your drivers but the lower resonance frequency (Fs) will be balanced by an increase in compliance (VAS) and there will be no difference in the sound of your cab. Of course, if you're expecting to hear a difference, chances are you will hear one. Then there is the matter of whether you can actually tell whether the sound has changed (even if it has) when there is a long gap between listening tests.[/quote] I wouldn't recommend doing this with our cabs if it didn't make a difference - I deal in truths, not pointless audio myths. Cms is the fundamental parameter which changes, raising Fs and lowering Vas. In a typical bass cab this will result in an increase in output between 50Hz and 100Hz - you can measure this and you can model this. And you can hear it! The lowering of Vas means you'll often get more output below 50Hz with a fresh woofer because it goes deeper in a small box, but as the sum total of output from a typical bass guitar and typical bass amp has much much lower output in the sub 50Hz region than the 50-100Hz region you'll hear a fresh woofer as having noticeably less bottom than a loosened up one.

Running in a loudspeaker is not about being careful when it's new, it's realising that the suspension is stiff when new which restricts the bass response - it just saves you have to gradually turn down the lows during your first few gigs. If you're running in non-Barefaced cabs I wouldn't recommend driving them to the amount of excursion or you risk damaging them.

Yes, it's on the agenda! Think I've sussed out the right balance of LF extension vs LF sensitivity, just waiting on the driver prototype...

[quote name='The Dark Lord' timestamp='1353709393' post='1877831']Aha. I do live near Brighton. Shame that they don't have a demo room though.[/quote] We don't have a demo room but there's space upstairs (in between the final assembly benches) to set out a few cabs and compare them - we had a local bassist in last week doing just that. Nice to hear someone other than me (or recordings) playing through them!

It's not so much more lows, as a smaller box for equal lows compared to a 1x12". But because the net internal volume is smaller the port has to be longer to get the same tuning frequency, plus you need space for the second woofer and the isobaric chamber, and then add on the thickness of the plywood, so instead of an isobaric 2x12" having the same performance as a normal 1x12" but being 50% of the size, it ends up being about 75% of the size (and obviously you have the extra weight and cost of the second woofer). Plus if the woofers are running full-range then you'll get comb filtering through the mids and treble as the rear woofer actually fires through the front woofer, so some frequencies are reinforced and some cancelled depending on their phase relationship.

Anything will sound good at low volume if the noise floor (i.e. hiss etc) is not too high and you can EQ it to deal with the deficiencies of the human ear at low SPL: Home practice is likely to be around 70-80dB, gigging more likely 100-110dB. If you want something small and tiny and hi-fi for quiet home use only than a single active studio monitor is probably the best solution!

[quote name='eude' timestamp='1352906616' post='1869220']There's two speakers in the SP212 cab, although aren't they acting as one, not really sure how isobaric stuff works... [/quote] Half the power is going into moving the front woofer (which makes sound) and half into moving the back woofer (which makes the front woofer think it's in a bigger enclosure but doesn't make any sound). So if you've got 500W going into an isobaric 2x12" the sound coming out is equal to 250W going into a standard 1x12" of twice the net (internal) volume.

[quote name='andyjingram' timestamp='1352215142' post='1860224']I'm fishing for replies here, but what I'm taking from this thread is that the main concerns are portablility. A larger body of air behind the speakers will of course affect the depth of the lows, but no-one has suggested so far that two smaller cabs will have a detrimental effect on the sound in an average setting (4x15" dub players notwithstanding). Right enough?[/quote] A larger volume of air behind each woofer will affect the bass response. But if you have a a 2x12" with 100 litre internal volume and 40Hz tuning and two 1x12"s with 50 litre internal volume each and 40Hz tuning, with the same woofers in both, the response will be the same as in the 2x12" each woofer only perceives halve the internal volume. The same would be true with a 200 litre 4x12" etc as each woofer only sees a quarter of the internal volume.

If you have two 1x12"s and one 2x12", both rigs the same total impedance, total internal volume, tuning frequency and drivers and crossovers, then they'll sound identical.

Just sent you a document Jonathan! I'd work through getting the unplugged sound as right as possible, then plugged in with no EQ using just the neck pickup, then try with just the bridge pickup, then try with both pickups. Only then start messing with EQ etc. By breaking the process into stages you'll develop a much better understanding of how to control your tone.

Don't bumblebees gain the extra lift, that simplistic calculation said was unavailable from their wing size and reciprocations per minute, through the creation of a vortex which generates extra lift compared to how a bird wing works? Usually when scientific theory differs from reality it's because the science is incomplete!

[quote name='Happy Jack' timestamp='1351066576' post='1846756'] And the angle of the dangle? [/quote] Well obviously that depends on the heat of the meat!

If you want to update the maths with more useful values, you're looking at ~50g moving mass on a typical single 12", ~80g moving mass on a typical single 15". Action and reaction being equal and opposite, there is indeed a reaction to the action. But they are both vector quantities and as such perpendicular to the floor, so shouldn't excite it that much. But something is definitely happening, you can hear it when you add or remove inter cab/floor damping!

I've never seen much sense in buying a lightweight rig and then carting an amp stand around with you. Foam is one of those things that actually costs far more than you'd think it should (hence the prototyping issue) so the IsoTilts may seem expensive for some bits of foam but conversely they do what an amp stand does with much less weight and you can chuck them in your gigbag with your bass. I was sceptical of cabs physically transferring vibrations to the floor directly but as bits of foam make a difference then something is clearly happening! Maybe what actually happens is that the cab is acoustically exciting the floor but by raising the cab on some suitable foam you damp the vibrations, as you now have a damped mass on the vibrating membrane - like the difference between fretting a string and muting a string?

[quote name='brensabre79' timestamp='1350983687' post='1845742']I thought part of the whole point about having the bass cab on the floor was to [i]allow[/i] it to couple, increasing the LF response. I mentioned raising my cab off the floor in another post and was warned about the de-coupling that might occur and how detrimental it [i]could[/i] be to my sound! In the end, it depends on the application.[/quote] As I said in that thread, but it seems to be quite hard to explain clearly, there are two sorts of coupling. One is mechanical coupling which is through physical contact with the floor causing the floor to vibrate - this is almost always BAD. The only exception is when you're playing a double bass with no amp and need more output. The other is acoustic coupling, where the floor reflects the downwards output (the lower hemisphere of sound coming from your cab) so it joins up with the upwards output and thus increases the useful output at low frequencies. The IsoTilt wedges will minimise mechanical coupling without losing your acoustic coupling, and increase the mid/treble audibility on small stages. Ordered the first ones from the foam people last Friday (almost exactly a year after the project ended up in limbo due to the cost of prototyping)...

Some are, some aren't. The Genz ones are pretty damned accurate though (more than your cabs) and a modelling preamp through that rig should be far too good for a ten year old!

Your cab is loud and can handle plenty of power and your band can't be that loud if you have a relatively quiet singer, so feel free to lift your cab as high as you need. However if you want to know more, read on... The boost in the lows that you get from having your cab on the floor doesn't vanish as soon as you lift your cab - all that happens is that instead of getting that boost from the low-mids downwards, the boost starts just working on the upper-bass down, then the mid-bass down and then the low-bass only, as the cab gets higher off the ground. With your cab on a typical chair or small combo, you'll still be getting the reinforcement on your mid and low bass (100Hz down), which is where you're most likely to need it. All this stuff is acoustic coupling and is usually a good thing. You get mechanical coupling where the floor is wobbly (wood, not concrete) and your cab's own vibrations (or the acoustic output from the cab) set it vibrating. Mechanical coupling is almost always a bad thing because it's like a big badly tuned bass drum rumbling along with your playing.

[quote name='countjodius' timestamp='1350509020' post='1839988']Thanks for the info Alex, good to hear from the Barefaced man himself! I wonder in that case if the Super Twelve may be too loud, so therefore to go with the Midget? Or the Streamliner 600 with Super Twelve? Arrghh too many variables haha[/quote] No such thing as too loud, you can always turn down! (And if the master volume is proving too sensitive don't forget there's the preamp gain (sometimes two of them), your instrument's volume knob, and your fingers). Send me an email - [email protected] and we'll work out if we have something that'll suit you optimally. As you said, lots of variables to consider so consider them we must!

My iphone autocorrects Xmas to Xmax...