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Phil Starr

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  1. Phil Starr

    Valve amps, how many watts?!?

    Those figures are interesting, and completely consistent with measurements taken at Glastonbury a few years back. Oh blessed day when bands learn to turn down and let the tech do the work, and protect their hearing.
  2. Phil Starr

    What makes this song great?

    I hate you, that's 22 minutes I need back. and now I have to watch some of the others too
  3. Phil Starr

    Valve amps, how many watts?!?

    That's a really good point. I choose the 40dB range not because anyone is ever likely to need it but because it means you have gear which can cope with most things and for a bassist 20dB over the 'average' gives you a healthy amount of headroom to play with. Your figures of 100dB FOH and peaks of 110dB (so a dynamic range of 20dB) look far more real world to me. It's also interesting (to me) because I think audiences are getting noisier. If they are generating 90dB of crowd noise then 20-30dB of dynamic range is probably all you are left to play with. It'll also be interesting for bassists to consider the implication of a band rarely reaching 110db. That won't all be bass of course, but if it was your Barefaced 2x10 would only need 16 watts to produce that sound level at 1m.* I sometimes wonder at the crazy levels of power people aspire to when most of the time their amps are operating at just about 10W Even then they probably ought to turn down and let the PA do the heavy lifting. I think what you have here is important for anyone trying to get to grips with decibels and questions of how loud do I need to be. The science gives you extra insight but it can't give an absolute answer. The type of music you play, things like compression eq and so many other things will come in to play. I'm not surprised that the country acts are both louder (on peaks) and quieter (on average) than metal bands but I suspect a lot of people over hear might be a little surprised that a country band would be more demanding of the PA than a metal band. For the OP who plays in a function band and who wears ear protection we can reasonably assume this is a fairly professional unit where the PA is producing what the audience hears and stage levels are sensible I think that a 100W valve amp would be more than adequate. If you want the audience to hear the same sound you do then you need to chat with your sound engineer about how to relay it on to the audience, or simulate it with tech. 50W would probably be enough depending upon what the rest of your band are doing whether you compress your sound and how you eq and even how far you stand from your amp but I'd start looking at 100W amps. *for those of you still looking at the maths: the Two10 gives 98dB for 1W. To make 110dB needs an extra 12 db. 3dB needs double the power and 12db need the power doubled four times which is 16 times the power=16W
  4. Phil Starr

    Valve amps, how many watts?!?

    Well Bill you might if you plan to play solo bass with all the treble rolled off, I suspect Joe intends to play with other musicians, noisy guitarists and such like. If he pushes the bass to those levels you can expect everyone else in the band to turn up to match him. That'll probably mean the band collectively are going to reach levels maybe 6dB above the sorts of levels we are describing. I'm talking about a capability of 40dB dynamic range with peaks of 120dB for each instrument. I don't think you are seriously suggesting safely going up to 160dB peaks. I've chosen to make a whole series of assumptions in my sound levels, without making it into a 101 acoustics paper I have tried to indicate which bits are factual and what my reasoning is based upon where I've made broad assumptions. I don't think they are anything more than one person's opinion offered as a guideline but they are based in real world experience. I'd absolutely say that a speaker capable of 120dB across a broad spectrum is going to match a drummer 90% of the time and one which will only do 117dB is likely to struggle at times in some bands. I'm trying to keep it simple too, there are so many variables. The only point I was really making is that there is no point in just purchasing more and more sound output just because you can, and that there are hazards in extremely high sound levels. There comes a point where you are loud enough.
  5. Phil Starr

    Valve amps, how many watts?!?

    It's slightly complicated with two cabs because the impedance changes so you may, or may not draw more power from the amp. That's probably less of a problem with valve amps of course as the output transformer means they should be able to match to most common impedances. For the same power doubling the cone area will give you an extra 3dB. That's how itsmedunc got such a good result from his Ashdown 4x8's I'm guessing here but an 8" speaker is pretty efficient if it gives 92dB/W. Two would give you 95dB about the same as a reasonable 12" speaker. Four drivers would double again so 98dB/W and two cabs 101dB/W a 50W amp into this would give an extra 17dB That will give you 118dB the same as you might get from a Two10 and a 100W valve amp. Two Two10's with a 100W amp would give you 121dB, with a little overdrive/distortion that would be as loud as a 124dB solid state system in practice. Louder than almost all drums and more than enough to permanently damage your hearing. At this stage I need to say something. Each 3db increase in level halves the time you should be exposed to noise. Anything above 85dB will damage your hearing permanently if you are exposed to it for too long. The 100dB levels we average on stage with a Rock band will start to damage your hearing in about 15mins without ear plugs. I have mild tinnitus. https://www.noisehelp.com/noise-dose.html
  6. Phil Starr

    Valve amps, how many watts?!?

    That's spot on. To avoid having to dig the log tables out as a ready reckoner all you need to know is that 10x the watts is 10dB extra and 2x the watts is 3dB. You can then make a quick rough calculation by adding the extra dB's you get for the extra watts. Sticking with the Barefaced 2x10 which gives 98dB for 1W and looking at something like a 400W amp. That's two lots of 10x power and then two lots of doubling (400 is 10x10x2x2) in dB's that's 10+10+3+3 or an extra 26dB, 124 in total with the Barefaced cab. You can only just hear a 1dB change in level so calculating it to within a dB is usually good enough. A 300W amp is going to give between 1 and 2dB less 122-123db which is close enough for most purposes. The other bit of the story is why it's important. A metre away from a drumkit the average sound level is around 103dB. An audience makes an ambient noise level of 85dB or thereabouts so your quietest bass note needs to be at that level and your dynamic range (the difference between the quietest and loudest notes) will be about 40dB. You'll operate in a range of 80-120dB in most circumstances and if your system will do this without distorting you are going to be able to cope with most situations. When looking at bass systems I always look to beat 120dB as a target. With a valve amp you can crank it up 3dB and it will distort, in the example above the distortion kicks in at 118dB, but because its a valve amp you will only notice it as a bit of grit on the very loudest notes and a lower power amp amp will still deliver.
  7. Phil Starr

    Valve amps, how many watts?!?

    I'd say the sweet spot for valve amps is around the 100W mark. Any more than that and they get pretty heavy, and expensive. you can get away with a little less power with a valve amp because you can drive them up to their limits and the resulting overload is quite pleasing rather than unpleasantly distorted. Remember valve watts and solid state watts are still watts though, there's no magic going on just nicer distortion. Even that Barefaced isn't mega efficient compared with the old speakers that used to be used with valve amps 98dB/W will give 118dB with a 100w amp. My 1x12 gives 121db with a 300W amp and is just capable of matching a drumkit. That leaves you 3dB down though I think you should be able to push an extra 3dB higher on average because it's a valve amp. I suppose what I'm saying is it's very do-able but you won't have a lot to spare on a very loud stage. If you had a couple of 2x10's then you'd be sweet. Hope that helps
  8. Phil Starr

    Easy 12" cab build

    I really like the look of those beta's in the 50l cab and I love the mid peak in their response, it's a nice wide prominence showing a nice controlled cone break up rather than the much sharper peak that the Eminence Delta shows. It's not going to be a neutral sounding cab but it's pretty much the response I dial in on the graphic when I want the bass to cut through live.
  9. Phil Starr

    Easy 12" cab build

    Double the volume would be good but you'd need to recalculate the ports, they tune that particular volume of air irrespective of the number or size of the speaker. If you decide to go ahead I can calculate that for you or you can do it yourself with winISD a great piece of free software. I haven't looked at that Celestion, it doesn't have the excursion of the Beyma but that would matter a lot less in a 2x12. I know Stevie likes the look of that driver and I'd trust his judgement. I quite like the look of the Eminence Beta in the 50l cab but for me it works less well in the 30l cab.
  10. Phil Starr

    Easy 12" cab build

    That's right, we put in four ports because we had some concerns over port noises shifting that much air through only a couple of small ports. The mk2 cab has a single large port. We stuck to the small ports in this cab because you can cut the holes more easily by using a standard hole saw. I tried a slot port too but decided it was tricky to build because it needed clamping whilst the glue dried
  11. Phil Starr

    Easy 12" cab build

    Not so far, apart from the corner bracing inherent in the design. The panels are fairly small and that helps and a simple touch test shows them to be no worse than a lot of cabs. My intention is to go through the sort of systematic process with a signal generator that Stevie used on the Mk2 speakers but band shenanigans means that I'm spending more time herding cats than usual. (and also playing bass and learning new songs, so not all bad) I'm also planning a new cab building technique with more elaborate bracing which would be relatively simple for home builders and I might use this cab as a test bed for that technique. It's always down to time really.
  12. Phil Starr

    Easy 12" cab build

    Just thought I'd do a quick update on this topic. I haven't had much of a chance to use the cab in anger until the last couple of weeks down to the usual band politics and lack of gigs followed by all the work involved in starting a new project. You've probably all been there. Anyway I have had the chance to try it out in anger at a full rehearsal. As a little extra spice the drummer has a 7 week old baby and hasn't been out for a while so was hitting things with a little extra enthusiasm, thank heaven for earplugs! So, I was back in the hall with the most appalling acoustics, all hard surfaces high ceilings, well you name it. To save anyone having to go back the speaker was designed to cope with this sort of space, and those pubs where you just can't get the bass sound right. The deepest bass was rolled off with a 2dB hump at around 120Hz to add a bit of thump so they didn't sound too bass light, a kind of old school underdamped response but with a modern high excursion driver using a single 12 built into a very simple 30l cabinet. To complete the picture I was using a Fender American Deluxe P Bass with a Markbass Tube everything set flat with VPF set at about 10.00 o'clock. We play pop/rock covers AC/DC, Queen through to Chelsea Dagger via Summer of 69 sort of thing (I've no shame) It sounded awesome, first of all really effortlessly loud with two guitars a keyboard and drummer really driving on it was really well up in the mix, not a hint of a clipping light on the input and with plenty to play with at the master volume. I have to say there didn't appear to be much in the way of high power compression either, it was over 30degreees outside, warmer in and we played for three hours without any noticeable tail off in performance by the speaker. This with a single 12 in a cab the size of an old fashioned milk crate. The sound? Well it was the sound of a P bass, punchy but sitting just right in the mix once the band got going. Not the sort of thing you'd set up playing alone at home where you'd probably want a bit more deep and some mid scoop but with a band just spot on. I can also report that in this really difficult room I had no problem in monitoring my own playing both with and without ear plugs. I know you can't trust someone praising their own design but this was meant to be built as a bit of fun, a demo at the bass bash, something I wanted to try. I fully expected to be building a 45l cab which to my mind modelled a lot better but thought I'd try a cab just on the silly side of 'too small'. it was only when we plugged it in at the end of the bass bash I realised it was worth sticking with. It started life as a curiosity piece really but honestly I'd recommend building one to anyone who wants something really portable, isn't too bothered about the top end (it has no tweeter/horn) and who is happy with a straightforward old school sound straight out of the box. It will cost you around £120 to build and once the parts are cut, well it took me around an hour to do the basic build in the video, maybe 2.5 hours in total including the pre prep and finishing.
  13. Phil Starr

    Power Amp questions

    +1 for the Peavey IPR1600 I have two for PA use, they are just plug in and forget, no real sound of their own and they just work.
  14. Oh that's interesting, I have a J Retro on my Jazz. I get lovely sounds at home and through headphones in particular but in noisy environments have had problems with not being able to pick out the bass. Swapping to a P the problem disappears and on days when I record the gig there is always plenty of sound out there from the J, I'm just not getting it. I've even wondered about going back to passive. The J retro has bass boost only so unless the bass is turned right down you can have a lot of bass boost without realising it. 3dB of boost is going to double the demand for power from your amp for a fairly subtle change in tone. I used to get some nice tones from the j-Retro with my old Hartke but with some strange shapes on the graphic. If you have a range of basses it might be worth investigating.
  15. It might be sensible to contact Barefaced, or you could try a pm to Alex to get him to contribute here. If the difference is only 1dB you'd only notice the difference when switching between cabs in an A/B test. Having said that the broadband sensitivity doesn't tell you much, most of what we perceive as loudness is about the midrange sensitivity so a speaker with a flatter response may sound quieter. There's also the reality that in practice smaller speakers usually need more power to get the same volume of sound, whatever the advertising implies. A speaker may be very efficient compared with other speakers of it's type but a 1x12 is never going to be as efficient as an 8x10. Then you had your original speaker for a while and you'll have been tweaking the eq to get the best out of it, it'll be a while before you get to the same place with the new one. I really wouldn't worry about where the gain and master volume are set. So long as you could keep up with the drummer and the sound isn't distorting then your amp is happy, maybe this speaker just needs driving a little harder and that's OK. Obviously if it's distorting and the amp is overloading then that's a different issue but if your speaker gives you less gain then the amp will have to give a little more.
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