LawrenceH

I have not found camping mats as effective as strips of thicker structural foam.

[quote name='discreet' timestamp='1328649688' post='1530768'] I contacted Markbass re this but got no reply - they're usually pretty quick to respond, so maybe they just don't want to give out this information. Do you happen to know what the roll-off is for the LM series, for example? Thanks. [/quote] Sadly I can't give a good answer, measuring response that low requires a better scope than my PC soundcard! But, if you look at the pre-amp filter section in the MB manuals you will see the response starts to roll off around 30Hz. It's hard to interpret this without knowing how they made the graph (and the graphs don't quite tally with published specs in one or two details). But the roll off looks pretty gentle, maybe 6dB an octave so if that's the case there would still be substantial benefit to a proper rumble filter. Whether there's anything happening beyond the EQ section I can't say. It would be nice if bass manufacturers published proper specs like respectable PA companies! The Genz amps from what I understand have a more extreme roll-off that starts a bit higher.

[quote name='ead' timestamp='1328600949' post='1529628'] When I started following and reading this thread I was firmly of the mind that the MT sounded like the next "must have" bass related gadget. However I'm increasingly more reluctant to click "Buy Now"; more so as 4 strings are quite enough for me personally. [/quote] I for one definitely didn't intend to put anyone off this product - not that this discussion seems to, judging by the speed at which they flew off the shelf Max answered all questions reasonably and was happy disclosing construction specs, which are of a high quality. Wrt to the 4-string versus 5-string, it won't have a negative impact on the tone of a 4-string, it's just that in theory you can 'get away' with a higher cut-off and even more protection if you don't want to go down that low. In practice a roll-off beginning at 25Hz or so will still offer considerable benefit [i]assuming your amp is outputting much down there[/i] [i]in the first place[/i] (a fair few will being to roll off to varying degrees around then, including Markbass, Genz). It's only if you are playing through relatively small/high tuned cabs to their absolute limits then it won't offer total overexcursion protection, though importantly it will still help a significant amount if the amp has minimal filtering of its own. These cabs are all tuned higher than the standard low E anyway, so you could either set a filter to begin rolling off around 42Hz or for ultimate protection you would compromise slightly and roll off higher but this will be audible albeit only on the lowest notes and only a modest amount (these cabs will already be 10 or 12dB down at this point). NB I would think based on spec the Thumpinator would be an excellent match for the Barefaced cabs, which quite a few people are running.

There is a varitone jazz plate available on ebay that incorporates a mid scoop, somewhere or other there is a youtube video (I think it's the same one as on ebay) where it sounds pretty usable. I guess these things work by using an RLC bandpass filter that bleeds the mids to earth, but calculating component values for your own, wouldn't that be dependent on impedance of the particular pickups used? That would make it more complicated

User nugget on here has offered to carve a binding channel for me for a very reasonable price - but it's on a defretted neck which I won't be refretting. The bindings should be do-able with a Dremel if you're careful, I'd have thought? I might have a go at this on my 'practice' neck. I'm not convinced by the stickers in photos myself, though perhaps they look better in real life. I think the stickers work much better on the VMs presumably because they're black, and under a layer of lacquer.

[quote name='LawrenceH' timestamp='1328541679' post='1528703'] I would guess (though don't know for sure) that if you're using the Pod cabinet models these will, if they're accurate, already roll off the extreme bottom end - mimicking what a cab would naturally do. [/quote] Plus many of those cabinet models will likely incorporate a boost in the mid-bass (say round 100Hz) up into the low-mids, which might exacerbate any issues with the subs.

[quote name='silddx' timestamp='1328534483' post='1528551'] I'm interested to know if the MT will tighten up my bottom somewhat and give me a little more controllable definition, and minimise the variables, since all PAs are different, as are the people operating them, and my FoH sound needs to be more predictable. [/quote] I would guess (though don't know for sure) that if you're using the Pod cabinet models these will, if they're accurate, already roll off the extreme bottom end - mimicking what a cab would naturally do. In any case, how effective the Thumpinator was in this context would also depend on where the subs are crossing over. 'Typical' PAs (if there is such a thing) cross over between 80-120 Hz (very roughly). Excessive boom could be as much a feature of poorly integrated subs outputting in the 50-100Hz band as true subsonic freq (sub-30Hz). SEs do like to turn them up until they wallop with the kick drum rather than aiming for flat response across the crossover! Also poor sub placement is often an issue (separated subs, one each side, is an inherently bad setup).

[quote name='Silent Fly' timestamp='1328522590' post='1528304'] From what you said so far, it sounds like you are not convinced by the [sfx] micro-Thumpinator. It is understandable. It is an innovative product and, as far as I know, there isn't anything similar on the marker. Some of my customers are a little bit risk-adverse and prefer to not take the risk (albeit limited). I understand their viewpoint. From what you write, it sounds like you know analogue filtering. If you need a bandwidth optimizer, the best options for you might be building your own version. In this way you can have a processor that is fine-tuned with your gear. [/quote] It isn't to do with risk, it is the engineering impossibility of a one-size-fits-all approach being optimal without variable filter cutoff frequency. It is a boutique product with high quality construction and a boutique price tag to match, so in that market context it would matter to me whether the product is matched to specific application. From a bit of delving it's apparent the Thumpinator as is wouldn't suit me as well as it suits others (eg 5-string users), but if there were slightly more detailed specs it would have been easier to work this out and wouldn't have required much knowledge of filtering on my part. My philosophy is that more information is always a good thing, it can always be ignored by those who aren't interested! Making my own is something I have considered but it is a lot of trouble for a one-off. However to make a more positive suggestion for sfx, if you ever decided to produce circuit variants, say perhaps a 4-string version or even a 'small cab' version with a filter tuned deliberately higher to match modern 'micro' rigs where every watt and mm of excursion counts, then I would definitely be interested. I appreciate you taking the time to address my questions even if you won't release any specifications, no offence taken and I hope likewise! Since you answered my questions on construction methods I have no doubts about the quality of the products

[quote name='Silent Fly' timestamp='1328288916' post='1525096'] I suggest you base your assessment on how the unit actually sounds and what other people you respect say about it. Just for my personal curiosity, could you give an example of typical HPF you are referring to? [/quote] Cheers Max, the ongoing discussion is interesting and useful, for me at least. So, a 'typical' HPF to me would be Buttterworth, Linkwitz-Riley, Chebyshev topologies for example. I do find your 'suggestion' a bit unhelpful in this special case (normally I'd agree), let me explain why. The Thumpinator is unusual for an effect pedal - we're NOT looking for it to colour the sound, rather the aim is speaker protection and increasing amp headroom. This is, first, hard to assess without destructive testing(!) and second, it is the nature of reflex cabs that whether the product is functioning optimally for a given setup depends [i]entirely on the particular speaker used and the lowest tuning of the bass being played[/i]. I say optimally (rather than just 'adequately') because you are suggesting the thumpinator is designed 'optimally'. Which I'm sure it is, but only within a particular set of design parameters. Because reflex cab cone excursion rises rapidly with port unloading below resonance, with a secondary peak above, by far the most critical factor for optimal protection is the filter cut-off frequency in relation to resonance. Filter Q is a secondary consideration, though still quite important. 'Typical' reflex cab tunings range from around 40 all the way up to 65Hz or maybe more. For optimal performance a sub-sonic filter should be tuned close to resonance. Cut-off too high and you will compromise the useful bass output. But, cut-off too low and the speakers can still over-excurse considerably. Similarly, relatively low q (say Butterworth) will give too gradual initial roll-off which might well affect the audible range adversely, whereas a high q filter topology with the characteristic boost above f0 could even potentially be damaging to the speaker if f0 is too low for that system! Cascaded lower order filters of different q at different frequencies could be used to minimise that boost while maintaining a sharp cut-off, but essentially it is still the interaction with system resonance that determines how well your filter is optimised. Incidentally in a system of cascaded filters like that group delay could come into play - it will be additive with the speaker increasing chances of audibility [i]in a system-dependent manner.[/i] Given that from your graph the thumpinator appears to be set to cut off low, (sub-30Hz) and with a boost above cutoff (unknown amount, graph not scaled) I would therefore suggest that for people playing 4-strings, particularly with small cabs tuned to give high output in the midbass region a sweepable HPF just employing a standard filter topology will give results closer to optimal. That is not meant in any way as a criticism of your product which it's clear is very well put together, just my explanation why I feel more detailed specs (eg filter -3, -10 dB points and maybe even max resonant boost) are in fact very useful to assess value in relation to my setup. If it was a distortion pedal of course I would say ears are the only thing that mattered

Hmm, I have 3 Jap Fenders from 3 diff decades and they've all been great, but my MIM had a couple of issues and from reports on here the US stuff it seems can vary - though I am surprised there are finish and fret dress issues. As you say though, the sound is great. The bridge...if it's a new US one it should be a high-mass vintage which are good - or is this an 'American Special'? Anyway with my jazzes I do find the necks are a bit more changeable with the seasons than my old Ibanez, I put that down to one-piece maple being inherently less stable versus laminate construction. Once they're settled there shouldn't be any inherent reason why it can't get a good low action as long as you're prepared to tweak it every few months. Perhaps it needs a proper fret dress?

Good choice! I bought one to sell on, eyeing a quick profit but I couldn't bring myself to part with it! I am just [s]butchering[/s] carefully defretting it now to justify keeping it. The pickups are hot and fat, I think it'll sound great as a fretless.

Hi Phil, Is the concave bow totally even or does it have a 'wiggle'? I would try tweaking the rod slightly to bring it slightly straighter and see what effect that had - I've found that nearly straight works well for me though I think it depends on the strings and playing. It could be wear on the lower frets though, are they noticeably worn?

Firstly, can I say thank you for the extra detail! It is useful. However, I don't understand where you have explained the difference between your product and a HPF on a typical crossover, perhaps I have missed this post but all I can see is one where you state that they are different without saying why. That is the point I'm not getting. [quote name='Silent Fly' timestamp='1328284951' post='1525014'] Filter topology is not an information I am ready to make public ... I would be surprised if Neutrik sold jack sockets with the gold coating that wears out after a few uses. [/quote] That is why I asked about brand! A very thin gold coating wears almost immediately unless alloyed, that's just an engineering fact, and better quality plugs are important for several reasons. Neutrik are excellent, of course, and are the answer I was hoping for. It is fair that you are not willing to state the full filter topology but the steepness of slope is a critical bit of info, are you willing to disclose this? If not, if I already have a 24dB/oct LR or BW-type filter I would like to know how your product matches or outperforms it. It can't be seen from the photo on your page because there is no scale on the y axis. Regarding my point that you don't get, it is that without knowing what it is that differentiates the product from a typical HPF other than a smaller box, it is hard to assess it's value. The construction info is useful and helps explain the cost, but info on the electronic behaviour is lacking. I am more used to products in PA/broadcast/studio work where the specs are generally disclosed more readily. Thanks again for taking the time to answer questions.

[quote name='Silent Fly' timestamp='1328265579' post='1524552'] I think it is down to the words we use more than anything else. I would use the words “more than I am ready to spend”, “more than I can afford” or “more than I usually spend for a pedal”. “Expensive” or “cheap” require the comparison with at least another product that performs the same functionalities. [/quote] Not exactly, perceived value also reflects cost and complexity of production. On the face of it, the micro thumpinator looks expensive for a high-pass filter. There are various PA crossovers with steep HPFs, though obviously input impedance would not be appropriate for passive instruments so they'd need to run in an FX loop. Rather than just saying that the thumpinator is 'professional' I would be very interested in what you think it offers in terms of electronics, ie filter topology, max clean output voltage/dynamic range, input impedance and any other design features. I have wondered about buying one in the past because it is a well-conceived device but without professional specifications it is too expensive/too much of an unknown in my signal chain. ps Gold-plated jacks per se don't matter (as I'm sure you know), it has to be a thick coating of gold not to wear out at the contact points with only a few uses. Good quality is far more important, so I'd be more interested in what brand the sockets are!

So, Dave of Firecreek guitars (user 'nugget') has a suitable jig and has offered to sort this out for me cheaper than I'd be able to set myself up for the job. I'll start a 'build diary' thread for anyone interested once this gets underway.

[quote name='brensabre79' timestamp='1328191279' post='1523315'] but if you run a flat amp into it, you'll get a pretty flat response. [/quote] Are you sure? Just that I thought these cabs used the higher sensitivity 12" drivers which are biased to the upper mids (rising response above 500k and again above 1k)? Pad that back and you lose the sensitivity advantages. The Big series with the separate mids are the ones I'd be looking at for true clear PA-type response. [quote name='brensabre79' timestamp='1328191279' post='1523315'] What you say about sounding 'too HiFi' I imagine to mean has a bit of a mid scoop (as a lot of hifi stuff does). [/quote] I agree with this, and it's a really important point when considering overall band sound IMO. It's too easy to impress with a mid scoop but unless you're careful about where you scoop exactly, it all gets lost in the mix. Centre it around 1-1.5k covering an octave and it all sounds very clean in isolation but loses the bite in the mix. On the other hand a lower scoop of between say 250 and 500 really makes a jazz/ray in particular sound tight but still growl. I don't like the default TC cab/amp voicing because they seem to emphasise just this muddy region. It works for some situations (P with flats, old-school vibe) but in general when I've mixed front of house I've found it a difficult sound.

[quote name='daz' timestamp='1328175707' post='1522910'] Speaking purely as an amatuer DIY person. Unless you are sure of yourself with a chisel, I would be very aprehensive about wielding one anywhere near an Aerodyne that I owned. [/quote] I feel the same, except if I understand correctly the purfling cutter does most of the critical cutting and the chisel will (hopefully) follow the line. Still, I think it has potential to go rather catastrophically wrong. [quote name='essexbasscat' timestamp='1328189354' post='1523273'] I'd be interested to hear this topic explored, as it's something I'd like to do as well, once I know how. [/quote] Looks much simpler starting with a neck blank, then you can either use a narrower fingerboard and have the depth as the channel, or if you want it deeper you can route with a couple of nice straight edges as guides. Best way I can think to do it with a shaped neck requires clamping it into a jig/sled to maintain a constant angle and provide a guide edge for a router bit plus space to work against. But if anyone has better suggestions or if the purfling cutter is something that can give good results for a careful novice then I'd love to know.

Hi all, I am currently defretting a 'practice' neck which oldslapper was kind enough to send for the cost of postage in preparation for having a go on my aerodyne jazz. All is going well so far, I've got the frets out, the nut off, the maple veneer in and the board sanded smooth with a 9.5" radius block (re-radiused from flatter, be 'interesting' to see how this plays!). Next I'll try epoxying it. But. For the aerodyne just to complicate things I quite fancy adding cream binding to match that on the body. I have a Dremel but no proper router, and looking at the various binding router bits on Stewmac, cutting accurate binding channels on an already shaped neck looks far from straightforward and would involve a high outlay on tools that I don't really want to make right now. So, would a purfling cutter and chisel be able to do this to a decent standard without a year's (and 50 necks' worth) of practice? I could have a try on the practice neck but obviously don't want to if it'd be a total waste of time. Alternatively, any of the BC luthiers fancy PM-ing me a quote for doing this? I know having a fretted neck bound is an expensive job with multiple stages but I'm hoping that since I'd just want the channel cut on an already defretted neck it might be more affordable. Thanks!

[quote name='tombomb' timestamp='1328048847' post='1521083'] Awesome. So essentially I want to tune a bit higher than 40, but too high and I risk farting when pushing the lows. Makes sense. What about tuning lower than 40, say at 30-35? Would that help support the 60-80 range (being roughy an octave higher?) [/quote] No, afraid it's the opposite, tuning lower means you get less volume up higher (80Hz region) and the cone will also move more potentially breaching xmax. Tuning lower protects the speaker below 40Hz at the expense of higher up. [quote name='tombomb' timestamp='1328048847' post='1521083'] Also, how much does it really matter? Will it be a really noticable about of drop off? [/quote] This is a good question, it depends on your sound preferences and how good you are at noticing! In my opinion a smoother roll-off is desirable but not often seen on a bass cab, and really it's not always such a massive problem. More noticeable than drop-off is when a driver has a boomy one-note bass type response, which relates to the next thing you ask: [quote name='tombomb' timestamp='1328048847' post='1521083'] It looks like the previous driver had a natural frequency of 38, the 18Sound's is 39, so not too different. (But again I'm probaby missing something and it's not just the natural frequency that affects the tuning) [/quote] Other factors are important which describe the electromechanical properties of the driver (Thiele-Small parameters) and together these describe the low frequency behaviour of a given driver in a given box/tuning. Manufacturers supply these specs. Luckily there is free computer software that lets you model the behaviour of a system based on these T/S parameteres including frequency response and cone excursion. A good program is WinISD pro alpha, if you're serious about cab design this is where to start and it isn't all that complicated. Obviously though, a frequency response plot is all very well but you need to relate that to what your ears hear to make sense of it in the real world! Good luck, fwiw I'd guess both those drivers will do the job with the 18sound being more 'bomb-proof' due to higher excursion capability. But the ampeg port sizes are quite small, this means you will likely not be able to get maximum bass from the 18sound without it 'chuffing' (air speed through the ports around box resonance is too high, messes up the port behaviour and sounds bad - solution = bigger ports lengthened to maintain correct tuning, down-size is it eats up internal box area)

If sanding proves tricky I'd try a sharp scalpel, and perhaps some heat?

[quote name='tombomb' timestamp='1327958442' post='1519595'] from the bit of research I've done the celestion's xmax of 2.5mm is pretty lacking compared to the 6.5mm of the 18sound, but I appreciate that this isn't the only factor. [/quote] Bear in mind that if Celestion reported Xmax the same way that 18sound did, they'd quote a figure of 4.5mm. However the 18 Sound is a much higher spec driver

[quote name='tombomb' timestamp='1327996729' post='1519925'] New to all of this but is it standard to tune to the lowest frequency you'll use, so in my case 41Hz? [/quote] No, a lot of cabs are tuned a fair bit higher than this - even Alex's stuff I'd imagine will be a few Hz above. There are three major considerations - one, what a bass guitar actually outputs at various frequencies, two, what these frequencies contribute to the overall sound you perceive, three, how a reflex ported speaker behaves either side of cabinet resonance. The first is very dependent on the instrument but without a lot of equalisation (think active pre with bass boosted) most basses playing an open E (or open B on a five string) will output less fundamental than octave harmonic. On the other hand though, string 'thump' rather than a note itself means a bass can easily generate substantial output well below 40Hz. The output curve of a bass guitar note relates to the second issue, that harmonic series is what tells your brain what bass note you're listening to more than the root itself and also that a lot of the 'power' you perceive from those low notes is actually from the harmonic of the octave above, around 60 to 120Hz. That's not to say you can't hear/feel the real lows, but most people playing without subs do well enough without them. So don't worry if your cab starts to roll off above 40Hz (nearly all do, they'd have to be ridiculously large in size not to). Room modes in the bass frequencies are also a complicating factor, too much bass can be a bad thing in a lot of situations. The third point about speakers is perhaps the most important - either side of cab resonance is where cone excursion rises, and if you tune too low then you get a region of high excursion right in the 'power' band around 60-80Hz. On the other hand tune too high and your cone excursion, which rises very rapidly as frequency falls below resonance, becomes a real problem. So it's a balancing act. An awful lot of cabs are tuned between 50 and 65Hz, and that is a range that seems to work well in practice though the higher tunings do tend to mean low notes, especially with bass boosted by EQ, will cause speaker 'fart out' if you're pushing things hard.

[quote name='GarethFlatlands' timestamp='1328032158' post='1520640'] Also, would it be worth trying out a neo speaker? The combo currently weighs an absolute ton. I'm conscious they're pretty expensive atm and don't want to spend a lot as it's not my amp at the end of the day. [/quote] The Peaveys cabs are so heavy that it hardly seems worth it, you'd only save 3 or 4 kilos out of about 9000