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Everything posted by Phil Starr
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[quote name='drTStingray' timestamp='1476903780' post='3158380'] The speaker coil power compression is interesting - I was not aware of that and have noticed when using one rather than two 2 X 10s. I had put it down to everyone else turning up but maybe not. [/quote] Yep, a few of the speaker manufacturers put up their thermal compression figures. Losing 3db at high temperatures is not too unusual and IME it absolutely happens under gig conditions. As you say it's quite possible that we put it down to other people turning up when we lose the bass halfway through the second set.
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How Do You Value Yourself As A Musician, What Are You Worth?
Phil Starr replied to blue's topic in General Discussion
To answer your question directly I don't think anyone here is paid what they are 'worth' for playing music. There's an excess of supply over demand. I put in 20 hours a week on bass and I get £50 in a good week. This is more personal though. For years you've been telling us how great your band leader is and how good your slot in the band. Has that changed or has one well paid gig gone to your head? It seems that the only way to realise your dream is to leave your current band behind. Well, there's no harm in looking but have a good look first. I know nothing about the scene in the USA but from your descriptions it doesn't look too different from here. There are very few touring bands that work five nights a week. Even huge international acts rarely sell out night after night, there's usually a tour organised for a few months with gigs mainly at weekends. 20 gigs is a big tour. The tour ends and the name band go back home or into the studio until it is time for next years show, the session musicians go and look for the next job. My wife has a saying, "don't put out your dirty underwear until you know you have clean". If you don't have an offer that gives you what you want then giving up a band where you say you are happy doesn't make an awful lot of sense. For years you have been saying how happy you are in a band where your leader organises everything and you just turn up and do a professional job of entertaining an audience. A man has a right to change but you've never struck me as a gambler. -
[font=helvetica, arial, sans-serif][color=#282828]There's another factor in this which we haven't discussed much here. I didn't put it into my over-long last post which was probably already complex enough. Anyway here goes. [/color][/font] [color=#282828][font=helvetica, arial, sans-serif]TimR mentions 1000W into thermally limited speakers. When you pass 1000W through a 2" voice coil it gets hot, really hot. This increases the resistance in the coil so your 4ohm speaker can become a 16ohm speaker, so the power falls to 250W and the sound level falls. In extreme cases this [b]power compression[/b] can be as much as 6dB. Running a modern ultra powered amp into compact speakers is going to give you more power compression than the old ways of low power into lots of speakers. It may be that running out of oomph (or should that be heft?) halfway through a gig with class D isn't down to lack of watts but too many watts into limited speakers which have over-heated. Google power compression in speakers This is what JBL have to say [/font][/color] [size=3][color=#000000][font=Verdana, Arial, Helvetica, sans-serif]"Speaker voice coils are made of copper or aluminum. As these voice coils increase in temperature during normal operation, the DC resistance of the voice coil increases. Greater voice coil resistance means less power transfer from the amplifier. As a result, the speaker will not play as loud when it's "warmed up" as it did when it was "cold". Some speakers may exhibit 3 to 6 dB of power compression. This means that power compression can have the same effect as taking away half of your PA!"[/font][/color][/size]
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[quote name='mikel' timestamp='1476736171' post='3156874'] Still no real answer to my question. Why a 1000 watt solid state amp when an old 100 watt valve amp can make your ears bleed? Why is a 1000 watt solid state not producing twice the DBs of a 100 watt valve? [/quote] I think you've got the answers all here already. Firstly as a number of people are saying you are comparing a remembered sound with what you are actually hearing today. Old time amps often struggled and when I engineered in the early seventies just getting enough volume was a real struggle. We resorted to lots of speakers and often large horn designs to make the most of every watt. Typically we'd go for speakers with 102dB/watt so you'd get 122dB from your 'typical' 100W bass amp. Few bassists use genuine 1000W amps, in reality 3-500W are more common especially if you stop looking at the advertising and look up the continuous RMS spec in the manuals. Through a modern bass speaker which may only produce 96dB/W that's also 122dB. A lot of modern cabs are also producing a much cleaner sound without so many huge peaks and troughs in the frequency response so they will sound less 'shouty'. I really don't think your 100W valve amp would hold a candle to a 1000W amp through the same speakers. The second thing is that when you are playing at 100W you aren't actually using all those watts. Lets say your loudest sound is a deafening (literally) 120dB, that first part of the loudest note at the beginning of the bar in your loudest song. Now imagine the quietest sound the audience will hear as you let a note sustain into fade below the hubbub of a gig at the end of the song. That might be 80dB. You've got a dynamic range then of 40dB and your average volume is 100dB. This means your modern speaker needs 4W to make your average sound, well within the capabilities of either the 100W valver or the 1000W ss amp. The rest is your headroom for louder sounds. If you drive the amps to an average power of 10W then you will want the amp to reach 20db higher or 100x the power of 1000W, which your 1000W solid state amp will do but your valve amp won't and neither will the 3-500W class D. The difference is that the 500W amp will distort nastily and sound bad unless you compress the signal. 3dB of compression won't be noticeable for a fraction of a second so you won't notice. The valve amp has a trick up it's sleeve though. It kind of compresses the power peaks naturally and so doesn't distort as much, and because of the way the distortion is structured 10% of valve distortion is acceptable in a way that 10% distortion in a SS amp isn't. So yes, your 100W amp through an 8x10 is going to match/beat a 400W classD through a 2x10, but swap the speakers round and it'll be entirely outclassed for volume. I'd beat you up a flight of stairs with my stuff though To answer your question I think subjectively through the same speaker you could probably get a similar volume with acceptable distortion from roughly half the valve watts so your 100W amp might well equal a 200W SS amp. They'd almost certainly sound very different and I admit I'd probably prefer the valve amp if you offered to carry it.
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Bass through guitar speakers- Wait, hear me out!!
Phil Starr replied to Kyron's topic in Amps and Cabs
[quote name='Kyron' timestamp='1476570362' post='3155377'] So... My question to the experts: Is there a modern speaker/cab that can provide the clarity and sharp response from the Vintage 30 fitted to my ENGL combo, but is designed to withstand bass frequencies? [/quote] [quote name='Bill Fitzmaurice' timestamp='1476583449' post='3155420'] Another option is to put a guitar combo atop a regular bass rig. Since you'd have two amps that opens up all sorts of possibilities, including getting Chris Squire's signature tone the same way that he did. [/quote] With the gear you have this has to be worth a try, it'll cost you nothing other than time. Roll off the bass going to the guitar combo and then tweak the eq on the bass amp to get the balance of bass you want to achieve. If you like the sound enough it might be worth pursuing a single box solution long term. It'll be fun to try. Alternatively you could try using the guitar amp as your on stage monitor and feed a mixture of miked up cab and DI to the PA to get your bass sound at the volume you'd like. -
just had a quick look at the manual, it looks like there might be a fuse sandwiched between the mains socket and the mains switch. If so you should find it mounted in a carrier which you can pop out with a screwdriver. Failing that there might be an internal fuse but you'd need to disassemble the speaker to take the amp out. Unless you are confident you can deal with mains electricity and also how to use a multimeter it might be a better idea to leave this to a tech.
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Bass through guitar speakers- Wait, hear me out!!
Phil Starr replied to Kyron's topic in Amps and Cabs
If you really want to pursue this then the conventional approach is to use lots of speakers, using twice as many means you only need half the excursion. This is the basis of 4x12 cabs for bass and 8x10's for that matter. The first question to ask yourself is what it is you like about the guitar tone, the brightness is probably down to the presence peak of the Vintage 30 in the 1-3kHz range http://celestion.com/product/1/vintage_30/ that is not much different to a similar peak in the Eminence Beta 12 which does have more power handling and more bass. http://www.eminence.com/pdf/Beta_12A.pdf . The other thing you might be liking is the lack of lower octave fundamental (the frequencies below 100Hz) which mask a lot of the other frequencies and can make things woolly sounding. It wouldn't be difficult to design out the deep bass frequencies or just to eq that way. A couple of Beta 12's in a sealed cab might give you a sound you'd like. Until recently Celestion used to make just the speaker you would have wanted with their Green Label models but they have recently reduced their bass speaker range with the introduction of the Pulse speakers. I suspect there are other good drivers to look at though. If you need them I have some of the T/S parameters for the vintage 30, sadly not the Xmax [b] Vintage 30 8ohm[/b] D – 0.26m Re – 7.3ohm Fs – 75Hz Qms – 9.3 Qts – 0.43 Qes – 0.47 Mmt – 29g Cms – 0.18mm/N Vas – 72litres Bl – 14Tm Rms – 1.35kg/s -
12' Bass Driver Recommendations *CAB BUILD PROJECT*
Phil Starr replied to CalDeep's topic in Amps and Cabs
The Beyma SM212 is a useful driver and gives the best Xmax performance in the price range. However for a 4x12 the Eminence beta is worth a look too, it has a nice midrange peak and in the right box would give a good punchy sound. It only escaped recommendation for our design because of the better Xmax of the Beyma which you need for a 1x12 on its own but which is less important with a 4x12. Give us some indication of the size of your cab and we can give better advice. -
As ever there won't be a simple yes/no answer to this. Every design is going to have a weak link in the chain, more liable to break than something else. The Hartke mentioned above for example has some heavy capacitors mounted straight onto a thin bit of circuit board and if it is banged about it will break there. Who would know? Someone has mentioned capacitors and electrolytic do need to be switched on and charged up from time to time. My Exposure hi fi amp recommends leaving it on and it has basically been on for thirty years apart from a couple of house moves. It still sounds good though my ears haven't fared so well. Valves however evaporate some of the metal parts inside when they are switched on and these slowly deposit inside the glass. Eventually they need to be replaced so leaving them on doesn't make sense if you aren't using them, but neither does turning them on and off four times a gig. They are also prone to direct damage if you move them whilst still warm. However for most components two factors comeminto play. When stored they are likely to get damp and corrode, using them will warm them and dry them out. At the same time using them warms them and the rate of all the breakdown of the components will double for every 10degree temperature rise. That's down to simple physics as the molecules that make up everything double their random movement with increased temperature. Confusing?
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Just that, I'm looking for something to do tonight in Orpington and none of the pubs seem to want to advertise on line. There's got to be someone here playing, a link to your band's site would be good too.
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Technical speaker question (for tonight's gig)
Phil Starr replied to leschirons's topic in General Discussion
Bad luck. It looks like you shouldn't have a problem. You should be able to just use the cab as a cab and it looks from the manual as if all the sockets are just normal parallel sockets. Just make sure you take a couple of spare speaker leads.. The Hartke may only take jack leads. Let's hope ot is still all working when you get there. Of course with something dropped like that even the cab might have suffered, can you go straight through the pa at a pinch? -
Bass too bright, loud 'clacking' when strings hit frets
Phil Starr replied to 1976fenderhead's topic in Repairs and Technical
[quote name='1976fenderhead' timestamp='1475747904' post='3148366'] The strings are not touching the pickups and their height seems well set up by the Gallery (even distance to strings when I press on the last fret), but they may be evenly too high. I have to try lowering them when I have time, really busy with work + band work now. I'll report if it made a difference. [/quote] If they won't touch the pole pieces wen you push the strings down then they won't contact them under any normal playing so it isn't that and you don't need to do anything. -
With amp modelling you will be putting out a high level signal and won't need another pre amp. You can go straight into a PA amp which will be cheaper than a bass amp. You can then go straight into a PA speaker if it is the right one. There's a couple of things though. Your speaker requirements are still the same, if you need two twelves for bass you will still need two PA twelve. Cheap speakers will still struggle to cope with that level of bass. One extra hazard are plastic cabs which will mostly be too resonant for bass. Going for active PA speakers makes sense but if a 2x10 is what you normally use then two ten inch PA speakers are minimum.
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Bass too bright, loud 'clacking' when strings hit frets
Phil Starr replied to 1976fenderhead's topic in Repairs and Technical
[quote name='timhiggins' timestamp='1475254440' post='3144510'] I would also make sure your pickups are the same distance from strings as on your fender. [/quote] I was going to say the same thing. When I started out tweaking I raised the pups to try to get rid of a weak G string problem (amuse yourselves here). Anyway I got a loud clack and louder through the amp. The magnet in the pup was pulling the string down and it was contacting the pole pieces. If you can push the strings down so they contact the pole pieces then they are too close. Maybe they were too high when you bought the bass and then when you lowered the action.... -
New to creating own bass lines - need advice... Thanks!
Phil Starr replied to danonearth's topic in General Discussion
Hi Dan, I think others more qualified than me will come along but you may be starting from the wrong place. A bass line needs to be both rhythmic and melodic.You can make a great bass line with just the root but you have to nail the rhythm. You can then start just adding one or two notes like the fifth and seventh, maybe only once or twice in a bar. If you jumps straight to a 1-3-5 progression for each bar it is going to sound like every song is 50's rock'n'roll. You mention Latin where the rhythm is crucial and baselines often use a lot of root/fifth/octave. A lot of jazz is going to use a walking bass line which contains a lot of scale tones but the critical part is the last beat of the bar which is a leading note. It is a note belonging to the chord you are moving to not the one you are in. It anticipates the chord change in other words. This all oversimplifies but what I am trying to say is that each style has its own set of rules and you need to be aware of them. Here's a good start at what you can do with root and ifth https://www.youtube.com/watch?v=VZUSEHkLS8Q -
The ports look right to me but I'll have to check later, I'm off to visit mum, who isn't well, for a few days. i don't think there was anything wrong with your calculations Stevie, just the Beymas being a little off spec.
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[quote name='stevie' timestamp='1475520605' post='3146622'] Inches? Really? [/quote]I think he may be as old as we are Stevie
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to get 55Hz out of the Fanes you'd need to have a big cab, as I said earlier you are more likely to be 10dB down, though I don't know the internal volume of the cab you will be using so I'm guessing a bit really. I think the bass is going to be a bit 'light' as i said earlier. You'd reasonably expect that from smaller drivers but I don't see it as a huge issue. Have a re-read of post #16
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[quote name='Mr Bassman' timestamp='1475449443' post='3146060'] Two Faital Pro's would probably out perform 4 Fanes and save some weight [/quote] [quote name='fleabag' timestamp='1475451709' post='3146065'] Hmm...i might have to let Phil answer that one [/quote] [quote name='Bill Fitzmaurice' timestamp='1475457369' post='3146083'] That's not the case, as two 8PR200 have 325cc Vd, four Fane have 470cc Vd. [/quote] Bill is of course right. Thanks. Effectively that means the potential for deep bass from four Fanes is better than two Faitals at the expense of about three times the weight. However better is about other things as well. Just by having two drivers vertically aligned will give you better horizontal dispersion of mid and upper frequencies as a result for most listeners the tonal balance will shift, they will sound different. Four drivers will give you more efficiency. The speakers have similar but not identical frequency responses and so there will be further tonal differences. I've only looked at the specs and not tried them so I'm reluctant to say any more than that they will sound a bit different to each other. I've just looked to see if there are any 'rivals' to the PR200's exceptional excursion figures and couldn't find anything in a quick search on Blue Arans website. I couldn't find any real rivals to the Fanes bang for the buck either. That's an awful lot of performance for the money and I know from the other Sovereign speakers I've used that reliability and construction are good. If you want to go ahead with this and weight isn't a big issue the Fanes are a good choice for an 8" speaker. The thing is you can go on forever with speaker design and never get to build something. For the price of four Fanes and less than the Faitals you could get something like a 15" Eminence Deltalite which would give you lower bass, about 400cc Vd and lightweight. It would be an entirely different project though.
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My backup amp is a spare PA amp, that way it is a backup for the PA or the monitors and it saves the trouble of carrying a spare for everything. If a gig is out in the middle of nowhere I usually have a spare PA speaker which can double as a monitor or bass speaker. In the end it's probably enough to just have a plan of what you will do at a gig when something goes down, DI into the PA is going to get you through and some sort of box to do the pre amp and tone shaping could also be a good idea depending upon what else you work with. At home I have my old Hartke 3500. There's backup and backup, if something goes down on the night you just need to keep going and so long as you can make a noise which isn't too awful it should be fine but you wouldn't want a week or so out whilst an amp was being repaired so an old but decent amp is always worth having around.
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In which case it is only a bit of wood but the principle of being able to get back to original may be worthwhile. When you come to fitting the new baffle put in some 1" batten and screw the new baffle to that. If you want to change it then you simply have to undo the screws.
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see I you can get the baffle out in one piece. Then you can restore the original if you don't like what you get. Good luck, I'll be really interested in the results.
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Another sealed cab question... Sealing a badly tuned ported cab!
Phil Starr replied to Bigwan's topic in Amps and Cabs
Does anyone know whether the 'crossover' is simply a high pass filter to the tweeter or a proper crossover. If the former it will work to protect the horn and the impedance of the horn won't be an issue but the problem will come because the betas have a healthy midrange peak which may add to the horns output and be a bit too much to sound good. If we can ascertain how the crossover is set up (photos would help) we might be able to give some advice. I'd advise setting up with the whole horn/crossover out of circuit however, it might sound quite nice as the Betas look like they have a nice response curve for bass. -
Actually the published tuning in the design diary weren't the port dimensions calculated by WinISD they are the ones we tested at Stevie's which were tuned fairly accurately in practice but not quite as calculated. (I confess I'd been fiddling with them and hadn't put them back to where they were supposed to be ) I've got the plots up in front of me and a higher tuning actually reduces excursion, but only by a tiny amount. Without knowing the exact way they were being used I still think bad luck with a slightly out of spec unit might be part of the problem. We'll probably never know unless you choose to get it re-coned and ask Blue Aran or whoever does it to tell you what they think when they take it apart. I think once you calculate the volume displaced by the speaker and the port volumes you are going to find both cabs quite close to 50l.
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I wonder if anyone has any statistical data on the failure modes of high power loudspeakers. I've certainly seen lots of burnt out coils in the dim and distant past and also speakers where the coil former has clearly made contact with the back of the magnet structure but few damaged mid/bass drivers recently apart from some older Eminence drivers where the aluminium coils have separated from the leadout wires I haven't had a speaker failure for a long time.