alexclaber Posted October 11, 2012 Posted October 11, 2012 Andy, you don't hear electrical watts. Over 90% of the wattage you put into a cab comes out as heat. Less than 10% comes out as sound. According to Hoffman's Iron Law, the bigger a cab and/or the less deep it goes, the better it will be at turning electricity into sound and the less waste heat it'll generate. Big Baby sensitivity = 94dB therefore efficiency = 1.6% Compact sensitivity = 98dB therefore efficiency = 4% Dubster sensitivity = 101dB therefore efficiency = 8% So 300W electrically into a Big Baby gives you 4.8W acoustic output (300 x 0.016) and 295.2W of waste heat. To get 4.8W acoustic output from a Compact you need to put in 120W electrically, whilst to get 4.8W acoustic output from a Dubster you need to put in 60W electrically. The Headlite is about 250W into 8 ohms so right at the bottom of the power we recommend for the Big Baby. Furthermore, it's not an amp I have any experience of but I have found that in general micro-amps do not produce as much power in the real world with bass guitar as their specs claim, compared to heavyweight amps. Some micro-amps do better, and they're the ones we tend to recommend more often. As I said in my email, I think you'd be fine in your band with a DB750 driving a Big Baby but I'd be amazed if the Headlite has enough power to play loud enough without obvious clipping. Quote
0175westwood29 Posted October 11, 2012 Author Posted October 11, 2012 [quote name='alexclaber' timestamp='1349943272' post='1832424'] Andy, you don't hear electrical watts. Over 90% of the wattage you put into a cab comes out as heat. Less than 10% comes out as sound. According to Hoffman's Iron Law, the bigger a cab and/or the less deep it goes, the better it will be at turning electricity into sound and the less waste heat it'll generate. Big Baby sensitivity = 94dB therefore efficiency = 1.6% Compact sensitivity = 98dB therefore efficiency = 4% Dubster sensitivity = 101dB therefore efficiency = 8% So 300W electrically into a Big Baby gives you 4.8W acoustic output (300 x 0.016) and 295.2W of waste heat. To get 4.8W acoustic output from a Compact you need to put in 120W electrically, whilst to get 4.8W acoustic output from a Dubster you need to put in 60W electrically. The Headlite is about 250W into 8 ohms so right at the bottom of the power we recommend for the Big Baby. Furthermore, it's not an amp I have any experience of but I have found that in general micro-amps do not produce as much power in the real world with bass guitar as their specs claim, compared to heavyweight amps. Some micro-amps do better, and they're the ones we tend to recommend more often. As I said in my email, I think you'd be fine in your band with a DB750 driving a Big Baby but I'd be amazed if the Headlite has enough power to play loud enough without obvious clipping. [/quote] ah ok alex, wasnt doing this to be cheeky just i know you are a busy guy but thanks for explaining it andy Quote
alexclaber Posted October 11, 2012 Posted October 11, 2012 It's fine Andy, I realise all this stuff is very complicated - I didn't understand it when I started playing bass! Am going to write some better articles about decibels and hertz etc and put them on the site. Quote
0175westwood29 Posted October 11, 2012 Author Posted October 11, 2012 that would be helpful, the only bit i found confusing was im so used to being like right my cab can take 600w and my amp is 400 that be fine and loud, all the other stuff as you say is confusing. :-) andy Quote
alexclaber Posted October 11, 2012 Posted October 11, 2012 The first step to understanding cab loudness is to throw away the lies about cab power ratings - most of them are useless. It doesn't help that there are manufacturers still talking about cab X have 500W power output. It's utter BS. 500W acoustic power output is more than the Pyramid Stage PA rig at Glastonbury, which is the size of a few large trucks and worth more than a large house. Read this: http://barefacedbass.com/uploads/BGM59%20Oct2010.pdf Although other manufacturers quote sensitivity ratings, most are lies - Ampeg and Acmes are accurate. Epifani claim 100dB for a 1x12" containing a woofer with 95dB sensitivity - to get that sensitivity you'd need three of those cabs! It's all rather frustrating, marketing trumping honesty... Quote
0175westwood29 Posted October 11, 2012 Author Posted October 11, 2012 [quote name='alexclaber' timestamp='1349954441' post='1832603'] The first step to understanding cab loudness is to throw away the lies about cab power ratings - most of them are useless. It doesn't help that there are manufacturers still talking about cab X have 500W power output. It's utter BS. 500W acoustic power output is more than the Pyramid Stage PA rig at Glastonbury, which is the size of a few large trucks and worth more than a large house. Read this: [url="http://barefacedbass.com/uploads/BGM59%20Oct2010.pdf"]http://barefacedbass...9%20Oct2010.pdf[/url] Although other manufacturers quote sensitivity ratings, most are lies - Ampeg and Acmes are accurate. Epifani claim 100dB for a 1x12" containing a woofer with 95dB sensitivity - to get that sensitivity you'd need three of those cabs! It's all rather frustrating, marketing trumping honesty... [/quote] ok i kinda get that! my head is still confused by the numbers tho, ie putting 300w into the dubster is like putting 1800 w into the bb, but its fine to put 500 from a db750 into the bigbaby? (i know ive probs missed the pont totally but feel like my heads gonna explode a bit) andy Quote
alexclaber Posted October 12, 2012 Posted October 12, 2012 Look it at like with cars. An efficient car might do 60mpg, an inefficient car might to 20mpg. Put 10 gallons into one and you'll be able to go 600 miles but only 200 miles with the other. mpg=sensitivity; fuel put in=power from amp; fuel tank capacity=max power handling. Quote
WinterMute Posted October 12, 2012 Posted October 12, 2012 [quote name='alexclaber' timestamp='1350031607' post='1833640'] Look it at like with cars. An efficient car might do 60mpg, an inefficient car might to 20mpg. Put 10 gallons into one and you'll be able to go 600 miles but only 200 miles with the other. mpg=sensitivity; fuel put in=power from amp; fuel tank capacity=max power handling. [/quote] What about acceleration, cornering and the leather seats then? Quote
0175westwood29 Posted October 12, 2012 Author Posted October 12, 2012 Ok no that makes sense! Just had thought as i like the eq and comp in headlite if i run it into a power amp from the slave to do the same signal what size amp would be good? All depends if i can find a bigbaby to try? Quote
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