LawrenceH

It's arguably worth it if the amp is quite low power compared to the speaker thermal handling, and you're just after a little more clean headroom where a couple of dB can make all the difference. That said there isn't an obvious 4 ohm equivalent of the 15" driver in your cab. Faital 15PR400 is probably closest but is still a dB or so quieter per watt in the low mids and is voiced differently, lacking the upper-mid 'bump' of the current driver so it'll sound a bit smoother, but a little less prominent in the mix. If you like the current sound but want more heft, adding another Compact is definitely the best solution.

[quote name='stingrayPete1977' timestamp='1384876866' post='2281753'] I have noticed that the resident experts on here are quick to tell everyone not to use mismatched cabs even though a 1x15 and 2x10 was a very popular rig for a long time yet the most popular mismatched rig I see now is normally some kind of Barefaced mountain of various cabs piled up with some on their side etc? [/quote] That's a different issue, we're talking running in series here - the impedance curve mismatch between the dissimilar drivers will Mess S**t Up. I agree that the theoretical problems of running different speakers (in parallel) can be overstated compared to real world situations. Sometimes it messes up the bass end, but even then you might not notice! The room will often do a lot more 'damage' to that region.

Some great discussion here! Best thread on speaker design I've seen in ages. I agree with others about the limitations of bracing, and the limited utility of pole cross braces. Pole braces are good as an easy fix for limited bandwidth subwoofers and not much else IMO as they only effect certain types of modal vibration. There are some models using FEA that have been discussed online, they have their limitations but they're useful for visualising the different bending modes that contribute to various resonances and making the point that braces themselves must be sufficiently stiff to be useful. See here if interested: [url="http://www.audioholics.com/loudspeaker-design/detailed-look-proper-loudspeaker-cabinet-bracing/finite-element-analysis-part-i"]http://www.audioholics.com/loudspeaker-design/detailed-look-proper-loudspeaker-cabinet-bracing/finite-element-analysis-part-i[/url] Also it's nice to see the distinction being made between the effects of adding rigidity and damping, and the effect of varying Q regarding the latter (eg uneven panel sizes). I like to see in terms of energy conversion efficiency. With increased rigidity you are increasing the overall energy converted to sound, whereas increased damping is converting more of that energy to heat. I'm not sure where the practical limit sits, but conceptually I favour stiff and as light as possible, to maximise sonic efficiency and reach a point where the resonances are at a high enough frequency that first there is a lot less overall energy to excite them and second damping becomes more effective. Stevie, I'd be very interested to hear more about your K12-alikes. I'm a big fan of those speakers, on another thread a while back I speculated that the moulded cabs sound decent (IMO) because the Q of the material is lower than eg wood - but that alone won't compensate for the loss of efficiency and so I'd guess that the wood ones sound 'tighter' and measure louder. I've also been building some PA cabs, using 9mm birch ply and quite extensive shelf and column bracing. I hope that these will still be pretty stiff (I couldn't lift them if they were 18mm birch! I want to try birch-faced poplar or similar), will get to the point of testing in a couple of weeks.

Glad to hear it has worked out ok, sounds like your experience has been similar to mine. For the stains I'm not sure, but something like xylene might clean them up a lot without having to take any material away- bit late now though sorry!

[quote name='Phil Starr' timestamp='1384328395' post='2275202'] Thanks Lawrence, I've pretty much decided to take your advice and I've started a test with one of the smaller dinks using my daughter's nail varnish. I think I might try superglue as well. Can't believe i'm experimenting on a £1000 bass! [/quote] Haha I only did it myself because I knew I could reverse it if it all went belly-up! Good luck

[quote name='Phil Starr' timestamp='1384246544' post='2274302'] Mine is definitely Poly of some sort, acetone doesn't touch it at all. You can get the poly lacquers easily enough from car parts shops and also Axminster Power Tools which does a good mail order service. The trouble is knowing which poly finish you are dealing with, Some are two part some single part, some solvent based and some water based. I'm guessing polyester polyurethane and acrylic. The other problem is that they vary in solids content and they are shy about this too. Nitro cellulose is good because the lacquer redissolves in the solvent and then cross links with the new lacquer so it is a complete repair. I'm guessing there is no way of cross linking polyurethane with new polyurethane, polyester with polyester or acrylic/acrylic. That is assuming I can find out what finish I have, I guess an email to Fender might tell me. Having said that I've successfully drop filled dinks in furniture with poyurethane varnish, which is slightly yellow due to the alkyd resins in the varnish. [/quote] Acrylic redissolves like nitro (at least, the rattlecan stuff does) - Fender stuff is definitely a 2-part catalysed finish that you can't redissolve, very nasty to spray but tougher than the poly you can buy in consumer cans or 1-part varnishes (or any other finish for that matter barring probably epoxy) The superglue on mine glossed up fine with wet'n-dry up to 1500 followed by rubbing compound, though I imagine the drop-filling with varnish would work at least as well, especially if you want a bit of yellow tint. If it were me I'd just go with whatever I had a pot of to hand!

[quote name='wateroftyne' timestamp='1383909931' post='2270641'] Not a fan, then? [/quote] Not got anything against them as I've not heard them, and the design is pretty tried and tested so I fully expect them to work well. Just that those driver combinations won't tread any new ground beyond where fEarfuls and indeed earlier generation Barefaced cabs could go (assuming I'm right - Eminence are listed as the driver suppliers so I think I am, and I'm not aware of Eminence moving to a new gen design) and indeed borrow an awful lot from them, so I find it funny that people are getting so excited about them. The Aguilar cosmetic clone does seem a little cheeky too. Of course there might be voicing differences but these are likely fairly minor because the drivers themselves limit your options in terms of sensible crossover points. If that still sounds too negative, let me reiterate - I expect these cabs to be very capable performers and for some the cosmetic options might make all the difference

I should say too, although I've stripped a polyester-coated alder body successfully using gentle heat, I definitely wouldn't fancy stripping a urethane-coated maple neck - hard to do mechanically without tearing into the maple and the polys are very resistant to chemical stripping in my experience. A job for a pro I reckon

The Fender finishes are typically a catalysed polyurethane (or polyester for cheaper instruments). As such you can't repair them like with nitrocellulose where you just add more and the fresh solvent does the work of blending it in, because the curing is irreversible. However I had quite good success making repairs on a dinged polyurethane-coated natural ash finish Fender by just flaking away the damaged area with a razor blade and then filling with superglue, before sanding and buffing. It was near-invisible in places but on the neck there was a slight yellow tint which the glue didn't replicate, at least not consistently (some did darken up a little, I think moisture is a relevant variable here). However the feel was perfect once rubbed down, which probably mattered more for the back of the neck, and the difference was fairly subtle. Superglue is soluble with acetone, which does nothing to a catalysed poly finish so you can always try it out reversibly. Bear in mind it'll eat through nitrocellulose and acrylic happily, as well as neck binding, so worth a quick double-check!

I'm sure they are great cabs. The options with mid driver look suspiciously like eminence alphas/alphalites. Guessing it's kappalite LFs for the neo woofer options too... is it 2009 again?

This Celestion might be worth a look for a screw-on solution, it's pretty new to their range which might be a good thing in relation to previous generation units: http://www.thomann.de/gb/celestion_cdx1_1010.htm It's another with a polyester diaphragm, from what I've read these reportedly sound a bit less harsh than a lot of titanium designs when driven hard, certainly that correlates with my subjective impression of the 18sound - n of 1 though!

[quote name='Phil Starr' timestamp='1383780972' post='2269185'] We always had limited gain before feedback too because of the peaky response. It is standard practice in hi-fi cabs with 2nd order crossovers to reverse the tweeter because of the phase shift in the crossover, so I tried it and yes it sounds better both in an A/B comparison and in a live performance. What did you do about inductors? I found them hard to source and expensive and in the end had them wound by IPLacoustics. [/quote] I will have to check the wiring in mine - perhaps they are already wired that way! I've quite often used them alongside other people's monitors and they have almost always given fewer feedback issues, and by ear the response isn't so much peaky as one broad midrange hump. You are convincing me that I should measure them properly when I get the chance. Inductors were Jantzen from audio-components.co.uk, there were other sites that listed cheaper but the postage for a small order was prohibitive. I used air core on the high-pass which was around 0.5mH, and 'p-core' for the woofer at 1.5mH. £20 for 2 of each, and another £30 for the other bits so £25 per crossover. I wish I had a better source of these bits!

[quote name='Phil Starr' timestamp='1383724992' post='2268072'] Thanks for this Lawrence, one I hadn't looked at. It has quite a droop in the upper frequencies but that could help in a monitor. You are happy with the sound and clean mids are what a decent monitor needs more than extreme highs. [/quote] The extreme top end of one of mine (10k and above) is quite ragged, doesn't give a smooth roll off at all, I did wonder about sending it back but it really doesn't seem that important live. I often just filter out everything in the monitors above 10kHz anyway and no-one ever notices! I used series-parallel resistors in the crossover to balance it up as much as possible, I like that way of doing it because resistors are cheap [quote name='Phil Starr' timestamp='1383724992' post='2268072'] Did you see my post about the yamahas? I've reversed the polarity of my horn drivers in my S112's which has knocked the nasty mid peak back a bit, really cleaned up the vocals and tamed some of the feedback problems. [/quote] I didn't see this no, I'll have a look. I have the IV series and I don't think the drivers are deltas, maybe betas? Been a while since I had them apart though - classic chipboard construction IIRC but with a lot of wadding for a commercial cab. The mid-bias is colourfully present but they have always been good performers in terms of volume before feedback, and the region where the boost is seems to be both quite broad and quite useful for a lot of vocalists to hear themselves. I built the new monitors with a similar form-factor to the Yams as I find it a useful one, but using braced 9mm birch. At some point I might scrap the Yamaha cabs and recycle the drivers, if this happens I'll measure them and tweak the crossover accordingly. The current one looks pretty cheap and cheerful; even with a 2nd order and no Zobel or resonators, and being a bit stingy on component ratings, my design was not that cheap unfortunately. But whatever compression driver you choose you face this same problem in my experience. Time alignment is a bloody pain as well with deeper PA horns in passive designs. Active DSP all the way (if only)

Hi Phil, I don't know about screw-on drivers, but I recently salvaged a pair of decent Celestion cast woofers from PA cabs we built in the late 90s and recycled them into sealed box stage monitors - for tweeters I used the 18sound XD125 (as used in fEarfuls) because they are dead cheap for comp drivers+horn, and was very pleasantly surprised with the results. Tried them out doing sound for quite a big-name vocalist who has discerning ears and they were enthusing about their monitor mix afterwards. They are MUCH nicer sounding than both my dog-eared Yamahas (Eminence ASD1001s into Yamaha custom CD horn - mid-biased so they cut through well as vocal monitors but it is a coloured sound) and my JBL Eon G2s (JBL 2412H-1" I think? A bit trashy up top), and a definite step up from the ubiquitous Em APT80. I went with an acoustic crossover of ~2.4k, 4th-order LR (electrically 2nd order asymmetric) - a bit higher than the ideal for 12" woofers so the response pinches in a little around 2k horizontally, and gives an alarming notch in the vertical polars. In practice thanks to the steep slopes the subjective sweet spot is quite wide (ideal dispersion characteristics of stage monitors is a whole other topic, I notice that many high-end designs use relatively narrow-directivity horns, something I'm not a fan of for smaller gigs). I did use measurement and modelling software to design the crossovers and they measure pretty flat throughout the crossover region; if I redesigned the crossovers for the Yamahas it might be a fairer comparison, but I can say overall they are very smooth-sounding speakers, relatively free of coloration in the vocal range. If I hadn't already had the woofers I'd have gone with 10s or even 8s, I think this tweeter would make a superb little vocal PA cab coupled to a mini woofer. One final thing - my understanding is that mating drivers, especially screw-ons, with random horns can cause issues due to resulting abrupt discontinuities in the flare profile. Apart from price this is the other reason I chose a driver+horn combined solution.

The main thing to watch for when using a decent power amp is that your preamp is up to scratch in terms of output level - pro power amps are designed for pro output level, they usually state the input sensitivity as part of the spec. Strangely, lots of bass preamps don't seem designed to match these. If you get it right then a pre+power amp combination beats most dedicated bass amps IMO.

The Bose system is a nice concept but if it's similar to their previous products, and user reports suggest it is, it is let down by component quality/power when you take it beyond a certain point. The HK elements system is an equivalent but made with good components, and the Fohhn Linea is the idea taken to the ultimate quality and power level. But you will still get feedback beyond a certain point with speakers firing into the mics, directivity control and high fidelity reproduction help a lot but they can only do so much, they're not magic - a conventionally-placed front-of-house system with high quality side-fill monitors is probably a better solution for those cases.

Alex I vented at you a while back for talking in marketing-speak rather than the more expansive discussions of old. I'm really pleased to see these new gen cabs announced, and REALLY pleased to see a decent discussion of design elements and philosophies on your site, which actually openly encompasses the limitations of the older designs. E.g. the reasoning for the change to high-quality 2-way is something I definitely agree with. My experience has been that other drivers had become available off-the-shelf that usefully surpassed the performance of the Kappalite series, but it looks like you have an OEM model that leapfrogs these nicely. I've not previously thought BF (or any manufacturer) worth it for me compared to DIY, but that's not the case any longer. I think I'll be buying one at some point (though if you wanted to sell me a driver even at a nice premium I'd be a happy customer ) EDIT: Also, the price looks very fair on these, I'm really impressed all round

[quote name='hamfist' timestamp='1372940260' post='2131858'] OK, they were fine in the days when a bass guitar in music really was only there to fill in the low end sonically, but these days, modern genres require so much more from a bass tone that IMO "traditional" designed bass cabs with their poor mid/highs dispersion are simply not fit for purpose. There ... I've said it ! [/quote] This is the crux of it really, does your particular sound require even dispersion above 1k or so? Plus, do the players who have their cabs below their waists realise how much they can be blasting a beam of treble death across a section of the audience to get it sounding right 30 degrees off axis, where their ears are? I am really interested in knowing more about which frequencies different players prioritise in the way they hear their sound, I am convinced it's really variable.

[quote name='alexclaber' timestamp='1372923926' post='2131581'] I think you're misunderstanding what I meant by 'uncompressed high SPL tone and bottom'. I wasn't just talking about the lowest octave of the tone, I was talking about everything, up into the many kHz. And in particular, I don't mean trying to get the F3 of the cab as low as possible because that causes a lot of compromises in other respects and as you say, is not always the most musically appropriate thing for backline. [/quote] But the bottom end is the only bit that really needs compressing in the better quality active PA cabs to compete with a deeper tuned, longer excursion woofer. On the other frequencies its just a bonus/safety feature that can eke out a few more decibels when necessary. Opinions vary and it's about where you choose your compromises but for me at PA level a good quality compression driver mated to a decent horn does the high kHz extremely well (though I must say I've no experience with ribbons). Beyond a certain point as well, passive filters just don't make sense any more. Bit of a rant, for which I apologise in advance. A few years back I feel you were more willing to discuss these compromises openly because you came at it from a DIY perspective - I'm sorry I missed the boat there, it would have been interesting to be involved and there's not so much DIY discussion going on these days - but now you have commercial interests I find your constant plugging of your products at the expense of others a little frustrating, your customers can do that for you, and do it well. These PA cabs under discussion are similar ball-park prices to your cabs or cheaper, but include powerful amps (and processing) as well that would cost several hundred pounds as standalone units. Of course there are going to be limitations which I've tried to make clear (it was me who pointed out the roll-off on the DARTS in the first place, and I also qualified the advantages by limiting comparison to 2-way designs). Nonetheless there are also advantages to these other approaches which make them valid alternatives. I also always make clear that I think you have good designs and I'm happy to believe they sound excellent, to the point where if I wasn't into the DIY I'd probably own one. I've made sure never to go out of my way to point out the design compromises in your own products in these discussions, because I think they are well-chosen such that they'd barely be an issue in the real world of bass amplification. I also think it would be a shame if people started worrying about things that they'd never previously even considered, that all their previous cabs had exhibited to a worse degree in the past! This is what happened with the fEarfuls, no? But it's still ok for them to appreciate the strengths of other design approaches and form factors. Designing ported loudspeakers is not particularly hard these days, in fact it's amazing what you can do just with a computer, some free software and a cheap calibrated measurement mic, certainly compared to when I started dabbling in the 90s. An actual r&d section with proper facilities is not going to lag behind. No-one has a magic product that's light-years ahead of the competition, just slightly different design priorities depending on product intended use and price-point. /rant

When I referenced the K series, it was as a midrange small-format PA system with some clever engineering that gets more from its components than it otherwise should - it's not considered 'high end' in the world of pro audio, just an example of a system that I've actually used (for general PA duties, though that includes bass), that if you factor in amp cost is rather good value compared to a lot of dedicated bass gear. There're sound engineers who sniff at it, but you look at the cost of what they use For Alex, an uncompressed bottom octave is obviously very important - as I've said, for PA that's not usually an issue in a 'full-range' box, and from a FoH perspective I think it's not always the most musically appropriate thing either for backline. Another thing to bear in mind when using PA cabs is you have to understand your signal chain very well to get the most out of it- it won't be plug and play if you're used to particular types of colouration/filtering coming from the amp and speaker. The issue of weight is interesting. Going off on a tangent... The usual argument put around on here seems to be that PA companies are cheapskates and can't be bothered to brace properly so use thick panels... but if you're shipping from China then I'd have thought a double weight box cost you a lot more in transport than a thinner one containing a few extra bits of wood when you're cnc cutting everything anyway - especially when the raw material will be cheaper as a result. Plus if you look inside a really good PA box it does contain bracing. There is raw strength as well, of course, PA stuff has to take stress at key points like pole mounts and fly points, these absolutely cannot afford to fail. But also if you look at serious hi-fi, they like ridiculously thick walls plus massive amounts of bracing as well! I would hazard a guess that one reason is, that it's comparatively easy to brace resonant problems away from the bass, but as you go up through the mid-range it gets progressively harder to push the modes higher, no matter what bracing strategy you use, ultimately you are limited by the stiffness of the material in its weakest plane, whether you're using i-beams, struts or full matrices a la the classic B&Ws (pre-stressed bracing is as I understand it a bit of a red herring when you're talking about wood, as it won't stay pre-stressed). What sounds beautifully clean on a bass guitar, may not sound quite so good on a vocal. I'm not sure what the scenario is with ABS plastic, obviously the advantage of moulding is that you maximise the stiffness of the geometry, but the material limit is still there - I wonder if it relies also on the material being inherently highly damped? Energy will get lost in the structure still, there's no free lunch, but it won't be so objectionaly audible compared to something that, as dicreet put it earlier, 'rings like a bell'. Anyway, back to the original topic...

[quote name='funkle' timestamp='1372833107' post='2130372'] No, the fEARless (or however the right way to spell it) stuff I think is all solely based around the 3012LF. So, in essence: most decent PA gear is designed to cross over to a sub at frequencies below 50 Hz, but will have better components and design for reproducing midrange and top end. Bass cabs will win on colouration of sound, small footprint and sub 50 Hz reproduction (depending on the manufacturer) but tend to lose out in accuracy of reproduction of thie mids. No active EQ or DSP built in, etc. Didn't Bergantino do powered cabs for a while with DSP? Their website doesn't have them listed anymore, I suppose the product line wasn't supportable in the market place. I'm really keen to go and try out a K12 now...though Talkbass users report not enough welly for bass without a sub. [/quote] Yeah, pretty much. I wasn't very clear about crossovers, for subs you typically cross around 80-100Hz, but the standalone cabs are designed to work ok without this when necessary, 50-60Hz being a practical lower limit (also there are advantages to crossing well above tuning frequency). I'm very suprised they say not enough for bass on the Ks, they sound massive to me (I notice there are two version though, the ABS plastic and the birch). But what they won't have is the hump that you get with a lot of cabs so that might be what they're missing? The pre-amp would make a big difference too. To me, these high quality monitorsr sound like what you get with a DI so it all hinges on what you drive them with.

[quote name='funkle' timestamp='1372798988' post='2130230'] Lawrence, what's your take on the cream of the bass cab 'full range' crop (Barefaced, Audiokinesis, etc) vs the cream of the PA crop (QSC K series, etc)? [/quote] Well, I've not used most of the boutique bass stuff (but I do have experience with some of the raw drivers, eg Eminence and to a limited extent Faital). But the PA gear these days is just incredible. Looking at it in terms of spec and design - the very best bass stuff generally has as good or sometimes better woofers than the small-format PA stuff (not necessarily so when you are talking really top-line systems, but they're for BIG sound). But the PA stuff generally has much nicer compression drivers and horn profiles, which makes a big difference in perceived quality IME. Barefaced are using a nice midrange (I thought it was Beyma?) but that tweeter is pretty long in the tooth. I don't know what Audiokinesis are using, it may be very good but bear in mind the [i]really[/i] high-end comp drivers cost more than the woofers! Having said that, the smaller PA stuff is, as far as I can tell, usually using decent but not eye-wateringly expensive components in this respect and making them sound great. The secret I think is in part due to the integration with the amps and DSP. I don't know of any bass companies doing this and I don't imagine most have the capacity/inclination to, at least not at that level of sophistication (TC as mentioned are a company that probably could). Bi-amping comes with its own real advantages anyway, and while DSP on top of that can't fix speakers that are total arse, it can make already good ones sound great, enhancing the strengths and making the compromises nearly irrelevant. The two areas the bass stuff may have an advantage as an all-in-one format are a) if you like the way typical mid-woofer cones colour the sound (I do actually, to a limited extent) or b ) if you want to go really low in a small footprint without using a separate sub, eg the Big series stuff, or I guess Acme? PA stuff is pretty much always designed to cross to a sub if you want to get much below 50Hz or have massive sub-60Hz output. What you could do is take something like a Barefaced and bi- or tri-amp with a good PA loudspeaker management system that incorporated eg delays, parametric crossovers and nice-sounding limiters. But that probably wouldn't be cost effective and you'd have to tune it to your system yourself. It's a real shame the Eminence D-Fend was released to consumers in such an incredibly sucky way, the OEM boards they demo'ed seemed like a really useful bit of kit for passive instrument cabs that offered some of the advantages of active gear in terms of bass management. Really though all this stuff is very nice whichever route you take especially if you understand how to set it up! Environmental acoustics are probably more of a limitation in 99% of gigs, and all this gear is designed to mitigate that one way or another (waveguides, directivity matching, EQ, ergonomics). Regarding the fEarless stuff, I don't think there's much new going on just a different tuning frequency and more compact midrange unit (it'll have a different voicing as a result, of course). Does it offer different woofer options?

[quote name='funkle' timestamp='1372765968' post='2129582'] I haven't managed to get any tuning info from the greenboy chaps on their forums. I did earn a fair amount of negative commentary for asking for it, though. [/quote] It's a shame, there was some good stuff over there initially, but I find it all a bit sycophantic and especially now he has launched commercial lines there's not much discussion of design philosophy regarding speaker cabs.They're nice designs but use well-established principles and by PA standards these are low-tech cabs (which is good from a DIY/small commercial builder point of view). FWIW the fEarfuls are tuned around 45Hz IIRC. [quote name='discreet' timestamp='1372496366' post='2126363'] Would not that black plastic housing ring like a bell at battle levels..? [/quote] Depends how well they've braced it - but yeah I'd be a bit wary of plastic cabs for bass, be surprised if there was actual audible ringing but it might be a bit weak and smeary around the low mids. [quote name='owen' timestamp='1372792625' post='2130122'] Not all PA cabs are equal. I used a Mackie SRM450 for a few months [/quote] A case in point - these are just not in the same class as the QSC, HK etc stuff (though I haven't heard the most recent incarnation) and I suspect the plastic doesn't help.

I don't feel any jealousy at the Mumfords, just mild irritation that because they're successful exposure to their crap is harder to avoid. I think they're popular because they write very simple songs based around the same repetitive ideas, so people who aren't really into music at all don't have to deal with any kind of learning curve or emotional intensity, and if they like one song it's a fairly safe bet the others won't offer any unwanted challenges. The good thing for me is I find them so unbelievably un-memorable that they don't stick in my head at all. The bad thing is they trigger unwanted REM songs to play in my head instead. [quote name='bassace' timestamp='1372675840' post='2128329'] No they're not. [/quote] What?! Even if you dislike both intensely, which is fine, you can still objectively analyse Bellowhead's arrangements and you've got tons of complex polyphonic melody, syncopation and polyrhythm. If you do the same with the Mumfords you find a hollowed out husk of mediocrity - well, not quite but the relative complexities in the music are totally different.

You can't normally sand a metallic finish without altering the way it looks - the flakes are meant to sit upright within the colour layer then usually clear-coated on top. This may not be the case with these thick polyester finishes, but it'd be a risky experiment! If someone wanted to do this who already had the bass, they could try carefully rubbing the decal with acetone (just in case it's done on top for economy reasons), acetone wouldn't damage the polyester but should take off any unprotected decal.