bremen Posted June 20 Share Posted June 20 I'm aware that the wider the speaker the narrower the beam, and that a pair of 10s mounted horizontally behave like a 20 (almost). I'm currently using 10 and even that is too pointy for me. Can anyone share a table or formula to estimate the dispersion angle against cone diameter for a given frequency? I'm contemplating a 4" driver crossed over at (very approximately)200Hz. Thank you. I'll go and post something on the Bad Jokes thread now. No swearies, promise. Quote Link to comment Share on other sites More sharing options...
BigRedX Posted June 20 Share Posted June 20 Is the problem for musicians on stage being able to hear you, or projecting out into the audience? Quote Link to comment Share on other sites More sharing options...
bremen Posted June 20 Author Share Posted June 20 Audience? What is this fabled beast of which you speak? It's mostly wanting to hear my own "tone". Meanwhile, I'm making an adjustable wedge that I can use to angle it at my ears. Quote Link to comment Share on other sites More sharing options...
Dood Posted June 20 Share Posted June 20 18 minutes ago, bremen said: Audience? What is this fabled beast of which you speak? It's mostly wanting to hear my own "tone". Meanwhile, I'm making an adjustable wedge that I can use to angle it at my ears. My immediate thought was this. Angling speakers towards your ears is the simplest solution. I just wish that all guitarists learned this sooner too. Often, with a speaker off-axis, the top end and upper mid-range (which bassists need for pitch definition) gets lost. Guitarists with cabinets sat on the floor poitning towards their knees will then crank up the treble and presence so it sounds nice and balanced where their ears are. The audience, being 'on axis' with the cabinet have to deal with razor sharp tinnitus inducing searing top end. So many issues could be solved if their speakers were on axis with their lug-oles!! Quote Link to comment Share on other sites More sharing options...
Dood Posted June 20 Share Posted June 20 I love having a full range speaker solution behind me to get the clarity where it is needed, (top end and all-important upper mid range as wwell as deep lows!) so there's definitely options out there. I wondered if soemthing like this as an add-on might help? I've never reviewed one, so I have no experience of. Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted June 20 Share Posted June 20 Adding a 4" mid will do the job, but 200Hz is too low for the crossover. 800 to 1200Hz is the appropriate range. Read this: https://www.basschat.co.uk/topic/496512-replacement-hi-mid-driver-for-tecamp-puma-110-combo/ 2 Quote Link to comment Share on other sites More sharing options...
BigRedX Posted June 20 Share Posted June 20 2 hours ago, bremen said: Audience? What is this fabled beast of which you speak? It's mostly wanting to hear my own "tone". Meanwhile, I'm making an adjustable wedge that I can use to angle it at my ears. In that case a solution that allows you to point the speaker at your ears rather than your legs is the most sensible one. 1 Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted June 21 Share Posted June 21 If you want a rough idea of when beaming starts just divide 13,512 (the speed of sound in inches per second at sea level) by the diameter of the driver in inches. Your 4" speaker would start beaming from around 3378 Hz, the 10" from 1351Hz Treat this as a rough calculation though; beaming is also affected by the size and shape of the baffle (front of the cab) and by the behaviour of the speaker cone. Speaker cones aren't rigid and all of them flex by different amounts so at high frequencies only the centre of the cone will be tracking the electrical signal which will also affect the radiation pattern. Beaming isn't dramatic at first, these are theoretical figures you'd need measuring equipment to detect and speakers are routinely crossed over an octave or two above these points. You did ask Point the speaker you have at your ears using a wedge is great advice, there are other reasons why a 4" speaker might not be great! Quote Link to comment Share on other sites More sharing options...
bremen Posted June 21 Author Share Posted June 21 Thanks, all, and that's a useful link Bill. I currently use a 15 and a 10, active variable 2nd order crossover. I was thinking about swapping the 10 for a 4 but probably a wedge for the a 10 is best. It does sound good on-axis. Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted June 21 Share Posted June 21 If you are an experimenter then you might like to try one of these as a 'bright box' . It wasn't waht it was designed for but I've tried it on top of a 1x12 driven by a PA amnp with a variable crossover. 180Hz worked really well and the beaming will be less, especially on top of a bigger cab. Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted June 21 Share Posted June 21 Quote Link to comment Share on other sites More sharing options...
choob.squeemer Posted June 21 Share Posted June 21 I've heard that wee cab - its remarkable - actually its remarkably remarkable 2 Quote Link to comment Share on other sites More sharing options...
agedhorse Posted June 24 Share Posted June 24 The formula for beaming is more or less correct in theory for a planer source, but in reality there are many other parameters like cone geometry, material, dust cap shape, attachment points, material, etc. The bet example where the predictions and real world speaker do not agree is the JBL D-130, where the off axis response is easily an octave or two greater than the predictions predict. Quote Link to comment Share on other sites More sharing options...
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