LawrenceH

Sorry Bill but you're still wrong about this. Count Bassy understands and has said much the same thing as me but expanded on the role of mass. A speaker cone vibrates, that creates the pressure waves in the first place. Now, third law of motion. It's not '95% acoustic 5% mechanical' it's 95+% heat, the rest mechanical. That mechanical energy will be distributed between the cone and the magnet/frame/whatever that's attached to.

[quote name='Bill Fitzmaurice' timestamp='1350996408' post='1845970'] Point of fact: Unless the cab is defectively constructed there's no such thing as mechanical coupling. That phenomenon can only occur if the cab walls flex [/quote] With all due respect, that's not correct. A diamond stylus is extremely rigid and makes a great mechanical coupler. Mechanical force can either be transferred, or converted e.g. to heat. With a rigid body it is being transferred, to the floor in this case. [quote name='Bill Fitzmaurice' timestamp='1350998366' post='1846002'] Since the cone is isolated from the cabinet by the driver suspension the effect of the feedback loop isn't severe, but it's there. [/quote] The force is generated in the motor. That includes the magnet, which is rigidly attached to the cab. Newton's third law - the force transmits into the cab as well as the cone. Efficient transfer of energy by a lightweight but rigid cab (without damping) will give greater vibration transfer to a resonant body like the floor. Mass greatly increases the force required to produce a noticeable reaction. This is secondary school physics in action!

I reckon it's sometimes worth having something without back windows or it's blindingly obvious a vehicle's full of valuable kit. But perhaps a van's even more of a target, the lure of the unknown? We've had a Vauxhall Combo before and that seemed decent enough, really good fuel economy too.

[quote name='brensabre79' timestamp='1350993932' post='1845926'] I guess I'm asking how is it going to be different to a stand (or a beer crate etc.) in terms of a solution to the problem? [/quote] Because foam is a better mechanical decoupler than a solid stand. Having said that, I've used offcuts of fairly stiff packing foam under monitor speakers etc for years and they work just as well as 'acoustic' foam in this application.

What about the issue that electric bass isn't a 'classical' instrument (and has very little in the way of established solo repertoire)? Drums have a lot of formal military stuff at its foundation, guitar has a strong classical/Spansh tradition, but e-bass started as either guitarists, or jazzers coming from upright.

[quote name='skej21' timestamp='1350769112' post='1843396'] I think the point has been missed here. The idea is that you start spot sight reading after the aforementioned 'chunking' has been done... I think the point Bilbo and I were making is that exposure to lots of new material after 'chunking' may be a more natural (and familiar) way to quickly develop reading skills. [/quote] I understood the point, but myself meant that 'chunking', as far as I understand, is not something you learn, master and finish - it is a continual process that gets ever-more refined as you integrate more complex groups (or you plateau and don't get any better at reading). I imagine different strategies for this suit different people. Practicing at tempo and not going back is a different thing but in a way easier, in that you can happily continually fumble the same types of thing unless you go back and work out what's going on. I must say though, I've never read on bass! Had my fill on piano

[quote name='TimR' timestamp='1350757689' post='1843236'] Lol. Coffin dodgers? Anyone over 45? We play all those. In fact loads of them get requested. Next time you're in a pub with a jukebox listen to what the punters are choosing (and paying!) to put on. [/quote] I guess it depends which pubs you go to, whether the punters are stuck 50, 40 or 'only' 30 years in the past

[quote name='Doddy' timestamp='1350750141' post='1843072'] It is,but I can honestly say that I've never practiced 'sight reading' once. The ability came from reading and fixing mistakes so that next time I see a particular note or rhythm,I can play it. I've never made a difference between 'reading' and 'sight reading'. [/quote] I agree with this totally - for most people (non-dyslexics) reading words, we get faster by by learning to recognise whole sets of words and phrases rather than spelling out each letter. In psychology this is called 'chunking'.

Hmm, I had an Ashdown Perfect 10 as part of a trade - muddiest, worst bass sound I've ever heard, awful at any volume. If you're looking to spend that kind of money then I'd assume it's for sound quality? Which is why I think the ultimate could be a great preamp/headphone setup, perhaps with a rumble pack to help 'feel' the bass. But at the lower end of the combo market the Roland stuff with built-in modelling is hard to beat for versatility of sound.

Can I ask whether these are with the Celestion Orange or Green label speakers? Also, what's the 'bass trap'?

Maybe I've missed it but I can't see 'Play that funky music' on any list so far? Been a LONG while since I heard a functions band that didn't play that one...

The AER really is an excellent performer - whether it's enough for gigs depends on what type of gig! But I've been at plenty as a punter where the AER was the only source for bass guitar and it has done the job and IMO sounded good to boot. It doesn't defy physics but I think it's well designed and contains a fair amount of electronics to make optimal use of the power/volume available. If you think how much 'punchier' and subjectively louder recorded music can sound through a given PA system than a live band, then it's clear there's a lot of potential - if you like the tonal changes that come with it, that's another matter (eg I don't like the TC heads much).

An SWR Marcus Miller pre-amp, some high-end open backed headphones and a little Yamaha mixer.

[quote name='muttley' timestamp='1350459701' post='1839025'] In the old days the formula for Xmax was often (coil length - front plate thickness)/2, sometimes adding a fudge factor "for good measure". Nowadays, with sophisticated kit like the Klippel distortion analyser there are various ways in which it can be quoted, for example within a certain % of max Bl (motor force) or shove factor (Bl[sup]2[/sup]/Re) or % THD. [/quote] Trouble is we don't have access to all the data to compare different drivers, and even then it's arguable which is the 'best' method though a lot of work recently seems to have been done on linearising BL curve across the operating range. Certainly can't account for all these in the small signal-based programs used by DIY-ers to simulate loudspeaker behaviour. Ears are a much cheaper and quicker way of gauging things! [quote name='bremen' timestamp='1350466162' post='1839124'] Trace 4 by 10s use Beta 10s, am I right? [/quote] Dunno what they use nowadays but Trace certainly used to use Celestion

[quote name='alexclaber' timestamp='1350408132' post='1838449'] But that's not massively relevant to bass cabs - the important bit is the interaction of direct and reflected waves, which you didn't say anything about because you said you didn't know why your low B could sound quiet by your rig and knock drinks over at distance tables. That is why! [/quote] That will be why in a lot of cases, but to assume it's always like that makes an assumption that the size of your listening aperture is constant (and negligible). I'd like to know more about the neuro/mechanical integration of signals in perception of LF. Fletcher-Munsen curves for example could be dramatically influenced by the method of sound delivery if our brains are using different approaches at different frequencies. Eg whether differing pressure gradients across our body are perceived differently to a relatively constant pressure gradient, or how much we use direct vibrational sensing from our torsos versus mechanical resonance effects that are ultimately integrated at the ear (ie prior to the brain). People talk subjectively about bass kicking them in the chest and small cabs not doing that. A small driver/cab driven to high excursion would probably have a different distortion profile to a large driver/cab with inter-modulation distortion and Bl curves and all that, which could be one explanation - but it would also differ in nearfield sound pressure gradients, in areas occupied by the player's body. Has anyone actually tried integrating a small cab with something like a tecamp pleasure pump (ooer etc etc)?

I'd be interested in knowing more about how people perceive low frequency sound in the nearfield - subjectively, I think bigger cabs up close do sound more 'massive' than smaller ones. High excursion and more power can compensate for larger area in terms of overall SPL but up close, a larger cab would give a more even LF dispersion over a body than smaller - however this wouldn't be significant further away. How many people find that small 'super' cabs sound more like the real thing from further away? How vibration is perceived and integrated with signals from the ear strikes me as an interesting topic and I'd be curious to try those rumble packs like the tecamp one, see what difference they made.

[quote name='RichardH' timestamp='1349884644' post='1831812'] I can't comment on what would happen if you altered or omitted the crossover to attempt to get a more full range cab out of it - and the 3015LF is an expensive driver to trash! [/quote] It wouldn't do any damage but you'd get the unfiltered response shown on the datasheet, which IIRC has a big peak just above 1k and then drops rapidly, so it would sound quite clanky but lacking in clarity.

[quote name='Beer of the Bass' timestamp='1350233963' post='1836087'] Oh no, that cab is definitely staying! It's my big ol' valve amp I might be reconsidering, so I had a fiddle around with WinISD just to remind myself of the capabilities of the cab. Trying the cab with your F1 made me wonder whether I really need to be lugging big lumps of iron around for the sound I go for, as there are clearly good sounds to be had from lighter amps. [/quote] Hah, I said it'd have to be a mad reason! You're obviously welcome to borrow the F1 if you've got any gigs coming up that'll push it a bit harder. If you think you'll take it to the limits, you've also got the know-how to build a decent HPF which would give a bit more breathing room, no? But I don't think you'd need it unless you had a really powerful amp, especially given that it's an 8 ohm cab

[quote name='Beer of the Bass' timestamp='1349990178' post='1833363'] it looks like WinISD uses one way peak figures (and I guess that's the convention?), so +/-4mm would be entered as 4mm. [/quote] Yup. As I've delved further I've found all xmax's aren't created equal and behaviour beyond xmax differs between different drivers in an audible way, so I reckon take the numbers as a rough guide and use your ears. Your cab with the B&Cs sounded reaaally nice I thought! If for some mad reason you want rid of it, let me know

Richard this looks great! I really hope you're going to expand out to cover some of the other GB cabs, the Crazy8 would get a lot of interest I'm sure. Glad to see two ply options too. I have to ask though, would you do thinner than 15mm ply in the poplar for those that are willing to add a few extra braces themselves? I've found the 12mm stuff perfectly adequate once suitably stiffened

Loads of overlap with 'post office' jacks in terms of name. But the jack that's closest to a 1/4" (type A) jack without being one and is probably the type B, have a look here [url="http://www.neutrik.com/en/audio/plugs-and-jacks/mil-b-gauge-type/"]http://www.neutrik.c...l-b-gauge-type/[/url] Similar enough to cause plenty of looks-like-it'll-fit-but-won't annoyances. Perhaps it's this one? EDIT one of these ones, I should say! There are a few variants...

Hah, I should've known that crowd would have been full of BC-ers. Thought all those who got up on stage did well enough, bassist laid down a lovely solid groove - though to say he was better than the big LG himself is going a bit far! Great night, the big US bands just know how to put a bit of theatrical energy into the performance in a way I've not seen from UK acts, good though many are

Can't help directly but the binding on the aerodyne is cream rather than white and matches up with a typical maple neck rather well (I defretted mine and used maple inlays, good match IMO)

I did rather more than 3 coats but that's because I wasn't using thinners to start with and had to sand back too much (with appropriate annoying waiting periods between). I think I made up about 50ml of the coating per go before adding thinner, which (obviously) made the coats thinner. I'd suggest applying that in several batches about an hour and a half apart, then leaving for the recommended few days (2?) in a well-ventilated warm environment, then repeating at least twice. The thinner I used, I actually mixed up myself because I had the chemicals handy - about 50/50 propanol and methanol I think, but just use the recommended Rustins stuff.

Hi Bob, sorry for the delay I've been away and only just saw your PM. Anyhow, I'd second the advice about not oiling the wood - it will likely mess up the coating and in any case it's totally unnecessary as the plastic coating itself will restore the natural lustre nicely. I think I used a bit of naptha-like spirits from my lab to clean the board (probably xylene) and it's probably worth a quick wipe to degrease, but I think you can overdo this. I found with my 'test' neck that cleaning too much eventually started leaching the colour from the neck along with the wood oil. The rustins was fairly forgiving to work with once I started using thinner, before this I found it was too thick and set too quickly trapping any bubbles, which are easy to form when brushing. I'd suggest starting with at least 20% added thinner. Mixing up in a glass jar and then leaving in the fridge for a bit with foil over was a good way of getting rid of excess bubbles at the beginning. Btw I used a radius sanding block for finishing, and it's worth getting the neck dead smooth before adding the coating as it's a b&*(^&r correcting even minor errors afterwards, as I learnt on my test neck. The plastic coating seems to shrink a bit over time a bit like nitro, so it starts flat but then little pores/dips begin to form if the wood hadn't been finished smooth. I'd even suggest trying the rustins grain filler if it's a particularly porous bit of rosewood. I waited about 2 weeks then sanded up to 1500 then T cut to finish. It was pretty mirror-like but to do a really good job I'd say go to at least 2000 first and use a higher quality 3M rubbing compound. Having said that the board already has snail trails from the roundwounds so probably not worth it. Only a very very minor cosmetic issue so far but I'll be interested to see how it holds up long-term. Hope that is useful, let me know if there's anything else.