Peter Cobbold Posted September 3, 2016 Report Share Posted September 3, 2016 Cheap https://www.amazon.co.uk/Decibel-meter-benetech-30-130dB-Pressure/dp/B01HLRSOQQ/ref=sr_1_19?srs=3861618031&ie=UTF8&qid=1472919541&sr=8-19 I think the Blue Book specifies noise as dBA ? - which is the standard used in this meter. Peter Quote Link to post Share on other sites
mike3739 Posted September 4, 2016 Report Share Posted September 4, 2016 Seems good value Peter. Cheers Mike. Quote Link to post Share on other sites
Alec Pringle Posted September 4, 2016 Report Share Posted September 4, 2016 Bear in mind that a proper piece of kit costs 4 figures not 3, and even a very simple half-decent budget meter is likely to be starting at £300 or thereabouts before you add the necessary accessories . . . . . and that is no more than a reasonable guide to noise level, not a professional tool . . . . Cheers Alec Quote Link to post Share on other sites
jerrytr5 Posted September 5, 2016 Report Share Posted September 5, 2016 I've got one of these. It was within a couple of dBA of the one the Castle Coombe scrutineer was using. As Alec says, probably not entirely accurate but a useful indicator for your exhaust. Jerry Quote Link to post Share on other sites
Peter Cobbold Posted September 5, 2016 Author Report Share Posted September 5, 2016 Jerry, That's encouraging as I think I am at least 10dBA too loud. Experimenting with silencers and inserts etc will be easier with sound level measurements, even if a bit off true. Peter Quote Link to post Share on other sites
john.r.davies Posted September 6, 2016 Report Share Posted September 6, 2016 (edited) Jerry, "A couple of decibels". Trouble is, the decibel scale is logarithmic. One decibel is ten times louder. But still, a guide is useful. I have a " proper" meter, old, analogue, and it should be calibrated and never has been while I owned, and it was second hand then, so no better than anything else. John Edited September 6, 2016 by john.r.davies Quote Link to post Share on other sites
Alec Pringle Posted September 6, 2016 Report Share Posted September 6, 2016 Hi John, one decibel increment is not ten times louder . . . . . but an increase of just ten decibels implies a x10 increase in loudness . . . . as opposed to the 10% increase that we'd expect on an arithmetic scale. Cheers Alec Quote Link to post Share on other sites
Peter Cobbold Posted September 6, 2016 Author Report Share Posted September 6, 2016 (edited) Doubling the sound level adds 3 dB. Because 10 x log 2 is 10 x 0.3010 =3. As Alec says, ten-fold louder sound adds 10dB. So 20-fold louder adds 13 dBA. Easier to work from a graph: http://www.sengpielaudio.com/PowerDB.gif'If I want to get exhaust noise from 110 dBA to 95 thats a reduction of 10-fold to get to 100 ( read 10 down to 1 on the graph) and another 4-fold to get down from 100 to 95 ( read from 10 down to 5 on the graph, corresponding to 4) total 40-fold. Ouch ! it needs a 40-fold increase in sound absorbtion as the present system is straight through.... Peter Edited September 6, 2016 by Peter Cobbold Quote Link to post Share on other sites
john.r.davies Posted September 6, 2016 Report Share Posted September 6, 2016 (edited) Ooooops. All this sun and seawater is addling my brain. It was Copacabana beach this morning, and Garota (Port.'girl') de Ipanema, the bar where the song was written, this evening. Who cares? They have the best 'chopp' (draft Brahma) and picunha (seared sliced rump beef) in town. Tchau! Joao, o gringo carioca. Edited September 6, 2016 by john.r.davies Quote Link to post Share on other sites
Motorsport Mickey Posted September 6, 2016 Report Share Posted September 6, 2016 (edited) Just to open up the Ipanema theme, I remembered how THE original Girl from Ipanema opened up a dress shop in her name and was taken to court by the executors of the writers of the song claiming she didn't have a claim on the title. Both the co writers had seen her 54 years ago ! and fallen deeply in awe of her and written the song about her completley "in lust", the court reviewed the information available and awarded her the right to do so, she WAS the Girl from Ipanema, Heloísa Pinheiro a Brazilian Playboy Playmate of the year, check out her photo at the bottom taken in 2006 when she was 61 ! She's now 71 !!. From Wikipedia, the free encyclopedia Helô Pinheiro Helo Pinheiro.jpg Pinheiro in July 2006 Born 7 July 1945 (age 71) Rio de Janeiro, Brazil Occupation Model and businesswoman Years active 1962-2003 Website www.garotadeipanema.com.br Heloísa Eneida Menezes Paes Pinto (born July 7, 1945), better known as Helô Pinheiro (Portuguese pronunciation: [eˈlo piˈɲejɾu]), is a Brazilian model and businesswoman. At the age of 17, Pinheiro became the source of inspiration for the song "Girl from Ipanema" when she was seen strolling to the beach in her native Rio de Janeiro's Ipanema neighbourhood by songwriters Antônio Carlos Jobim and Vinicius de Moraes.[1] Pinheiro became a Brazilian Playboy Playmate in 1987 and once again in 2003,[2] when she did a pictorial along with her daughter, Ticiane Pinheiro. She also appeared in the second season of The Amazing Race, for the Beach portion of the first Detour clue, and on America's Next Top Model, Cycle 12, for a modelling challenge in Brazil. Girl from Ipanema legal case[edit] In 2001, the song's copyright owners (the heirs to the composers) sued Pinheiro for using the title of the song "Garota de Ipanema" as the name of her boutique.[3] In their complaint, they stated that her status as the inspiration for the song did not entitle her to use the title of the song commercially. Public support was strongly in favor of Pinheiro. A press release by the composers, Jobim and de Moraes, that named Pinheiro as the original "girl from Ipanema" ("garota de Ipanema") was cited as evidence that they had intended to bestow this title on her. The court ruled in favor of Pinheiro. Mick Richards Edited September 6, 2016 by Motorsport Mickey Quote Link to post Share on other sites
john.r.davies Posted September 7, 2016 Report Share Posted September 7, 2016 Too much detail, Mickey. No more, please. The Girl will for me, as for Jobim and Moraes (read the lyrics) always be a myth, an impossible, unattainable, perfect dream. John Quote Link to post Share on other sites
john.r.davies Posted September 7, 2016 Report Share Posted September 7, 2016 A loose translation of Moraes' text, not the English version. Look, such a sight, so beautiful, So filled with grace, It;s her, this girl who comes and who passes, With a sweet swing, on her way to the sea. Girl with body of gold From the sun of Ipamena, Her swing Is more than a poem, Is a sight more beautiful Than I have ever seen pass by. Ah, why am I so alone? Why is there so much sadness? This beauty that exists, This beauty that is not only mine, That also passes by alone. Ah, if she but knew, That when she passes by, The world smiles, Is filled with grace, And becomes more beautiful, Because of love. Quote Link to post Share on other sites
littlejim Posted September 12, 2016 Report Share Posted September 12, 2016 There's a bit more to dBs than you would think, going on the above! Didden noe the song was based on a real person until now. Quote Link to post Share on other sites
McMuttley Posted September 28, 2016 Report Share Posted September 28, 2016 Cheap https://www.amazon.co.uk/Decibel-meter-benetech-30-130dB-Pressure/dp/B01HLRSOQQ/ref=sr_1_19?srs=3861618031&ie=UTF8&qid=1472919541&sr=8-19 I think the Blue Book specifies noise as dBA ? - which is the standard used in this meter. Peter Have ordered one for my nasty neighbour for Xmas, nice compact size, so should be easy to instool it where the noise doesn't shine. Quote Link to post Share on other sites
Peter Cobbold Posted September 28, 2016 Author Report Share Posted September 28, 2016 (edited) Have ordered one for my nasty neighbour for Xmas, nice compact size, so should be easy to instool it where the noise doesn't shine. Austin, An infrasound generator feeding your hifi at full power should be effective against nasty neighbour. You'd have to leave the house when its working. I think 7Hz will get their guts rumbling a treat. http://www.brighthubengineering.com/diy-electronics-devices/98687-build-an-infrasound-generator-circuit-for-ghost-effects/ But it will also affect nice neighbours... The French army built a machine for warfare. But it backfired, was impossible to aim in one direction. Peter Edited September 28, 2016 by Peter Cobbold Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.