Guitar Amp Myths Part 2 - Why Wattage is NOT a good measure of how loud your amp will go!
ฝัง
- เผยแพร่เมื่อ 2 พ.ย. 2018
- Captain Anderton recently caught up with Blackstar senior engineer Paul to tackle one of those big questions, will higher wattage give you more volume?
Let us know what you think in the comments!
This is a 4 part series... Part 3 is out next Saturday.
Blackstar range: goo.gl/MzuvVq
Interested in other Andertons TH-cam channels? Click on one of these links to find out more…
Andertons Guitar & Bass TH-cam Channel: goo.gl/kRJCpb
Andertons Drummers TH-cam Channel: goo.gl/9yKSS9
Andertons Keyboard TH-cam Channel: goo.gl/ns172M
Andertons Music Tech TH-cam Channel: goo.gl/Pmy8Ao
Andertons Shopping Web Site: goo.gl/TPsG2Q
Buy a T Shirt: goo.gl/TrTe78
Make sure to subscribe to Andertons TV for more great videos like this: goo.gl/aAzyQM - เพลง
Amp volumes ought to be measured using an “amp vs drummer” rating as that is usually what determines whether you can be heard or not!
Or voice level vs tv watching the avengers movie on the home theatre rig level
This is the exact reason I’m here now!!! We just got a new drummer and this dude plays hard af! Like Vinnie paul mic’d up thru the house and playing thru a 20 watt line6 or some junk. I have to practice thru our PA to play over him. I need to get louder without traveling weekly with 6 guitars, 100 watt head, and 4x12 cab plus the PA. I’m using a small enclosed trailer to haul my rig to practice. It’s ridiculous really
@@southerntrendkiller2632 I just bought a fender champion 100 2x12 solid state amp and my drummer gets drowned out by this amp. It pushes enough air to dry your clothes lol. 400 dollars. best buy and best amp I've ever had.
YES!!!’
Incredbily clear and informative talk from Paul here - understand more in 12 minutes about how amps work than I did after playing half my life!
To much volume not enough talent, my biggest problem.
schecter seven hah, mine too :-)
Too *
#metoo
Same story for every beginner with a little spending money
This was commented almost a year ago, how are your guitar skills now ??
For easy reference amps should have a graphic "Neighbour Rating", like
🏡 😠😠😠
Well done, comprehensive without being pedantic. You covered all the major issues in enough detail for anyone buying an amp or cab to feel like they can make an informed purchase.
I'm glad you found it useful. With so many viewers of varying technical level it's often hard to know where best to pitch these things. I just try to pretend I'm explaining it to a mate in the pub. Thanks for watching, Paul.
Videos like this are the best thing to happen to the community. This will make the consumer smarter to make their own decisions rather than asking TH-camrs endlessly for opinions. I would suggest the next series to be the electronics of the guitar signal chain. Not for nerds but as a supplement for the musician.
I got rid of my 5150 III to go Blackstar: HT40 MK-II. Much better & more versatile tone. Thank you, dudes at Blackstar!
I think it would have been also nice to point out that people buy higher wattage amps just to be able to get more headroom, not just volume. But I really enjoy this series and am looking forward to more. Thumbs up!
Exactly - that's why old fenders are insanely loud.
Yeah, I want an old Rivera S120 head because I want a stereo amp for a wet-dry-wet rig that won’t distort on its own at the volume I play (and the combo is open-back instead of closed-back).
Yes you are right. Thanks for watching, Paul.
I prefer higher wattage amps for it's low end capabilities.
A 5E3 amp will never have the same low end as a 100W Laney AOR with the bass knob pulled.
PS : .....i love 5E3 amps too !
To be fair, I'm not sure there's an easy way to explain engineering
To be fair, I'm not sure that if a thing isn't easily understandable for 1 person it means it isn't easy :p. Just joking mate, its a complicated thing and I reckon he gave it his best to make it understandable for everyone.
@@jeroenleeuwerke6585 Thanks, I tried to explain things in 'layman's terms' but occasionally slipped back to nerd mode. Paul.
@@Blackstaramps In my opinion you did a great job at explaining it all. By doing some research when I didn't know what some tech term ment I actually understood, and on top of that learned a lot. I reckon it is hard to explain a thing that comes natural to you, to a person that has a lack of basic knowledge. I'd love to see more of these video's since I sincerely enjoyed 'em.
Have a good one.
@@Blackstaramps I think sometimes you have to be careful using too much layman terminology. Sometimes that means you end up using language that can misunderstood cause it's not as clear as the technical terms, and so people start getting the wrong idea.
In the end I think the best thing is to just try and educate people on what sort of questions they should be asking when buying a new amp, and also maybe how to ask them. Then, hopefully, you're asking someone with the actual knowledge to give you a good answer.
Paul, thanks so much for doing these. It is heady stuff for a lot of us, but it's also so eye opening. I've had so many misconceptions for a long time about Watts, Speakers, Volume, Solid State, etc. It's great to hear the truth from someone that really knows what they're talking about.
But when your playing in your bedroom, 5WT small Marshall the same loud like jet airplane.
i can confirm this, if i play my 5w marshall tube amp even at the 1 watt setting at full volume i would go deaf in about 10 minutes of playing
Man, didn't you listen! A 5W can be surprisingly loud. It takes these 50 - 100w to push through the odd frequencies. A 5W like my Randall RD-5 might sound very good at "bedroom" levels but if it goes above, a 20w easily beats it in headroom. When we push 12 inch speakers we anyway need a slight above bedroom level to make these monsters work. Don't forget that!
This is why (nearly) everyone needs a way to play through only headphones. I make no claims WRT solid state with a speaker-emulated headphone jack vs analog modeling vs digital modeling vs anything else, but “bedroom volume” is a myth when it comes to not waking people up one room over.
Micro cube for the win!
5w is pretty much great for home alone or another guitar player.
if you have a 50w, it doesnt work properly nor sound good at 5w.
I love how this actual amp builder's answers completely contradict so many would be youtube engineers. Also, so cool finally understanding why my AC30 is so much louder than my old fender 65 watt solid state amp I learned on.
Lee and Paul, thanks so much for doing this. I can't express how helpful all this stuff is. I've been steadily learning more about guitar amps over the last couple of years, and I've realized how many biases (pun intended) and misconceptions that I've had for a long time. Thank you so much for the info!
Fantastically interesting video with the flow of information almost completely ruined by TH-cam deciding to put 4 adverts in an 18 minute video.....
I saw no ads other than the little things across the screen that you can delete in seconds. Fussy, fussy. It's free, eh?
As you say, fantastically interesting video from Anderton's; I use the ad times to read some of the comments. The ads pay for the "free" videos; I like to keep things free like that.
One word: Adblock
@@melvynobrien6193 sadly mine were full screen not the little ones...so they just interrupt the whole video. Happy for ads to keep things free but keep them at the front...don't just randomly throw them in the middle of a video .... and 4 in 18 minutes is taking the p**** a bit...
I believe the channel sets those.
More videos like this please. I love listening to an engineer trying to talk in a way that normals can understand. He did a great job. I could listen to him talk amps for hours.
Thanks for your nice comment. I'm so glad it has come across interesting and accessible. If only my girlfriend could listen to me talk amps for hours!
Captain and Paul,
I love this series!!! Lots of great information.
I am a huge fan of the old Tubeworks MOSvalve power amps for my main rig. To me my setup has always produced very “tube sounding” results.
Here comes the “fan boy” part of my post...
A few years ago while shopping for a guitar for my daughter I plugged into an HT20 and was blown away by its tone! I bought the amp on the spot. I brought it home but was just a bit concerned that it wouldn’t be loud enough when jamming with a few of my friends. I returned it and went with the Club 40. That amp really blew me away. All the clean headroom I needed and a killer distortion to boot. A great pedal platform or stand alone rock machine.
I am looking forward to the next installment in this series.
Hi, I'm glad your enjoying the videos, makes all the nervousness worthwhile. Paul.
Nice!! I'm really enjoying this series!!
Hi, I'm glad people are finding the videos useful. Paul.
This should be interesting!
PS: I wish Cap would let them end their explanations though, instead of cutting them off. It sounded like there were a few more interesting things going to be brought up, and now we'll never hear them…
@Guitar Hobby Most of the time, I think so too. This series, however, feels rushed to me, like they want to keep each episode under 20 minutes, and it shows in the point I mentioned above, IMHO.
I think he did that to keep it understandable, at least that’s what it did for me. So I was glad the Captain did that.
Lee actually helped things with his experience of doing these videos. I don't mind interruptions, gives me a chance to breath, lest I descend into nerdy jibberish. Thanks for watching, Paul.
patfix, maybe ask your question here if there is something you want elaborated on ... Cap said to ask questions in the comments below.
Lee thanks for bringing it back down to the ground at the end.
This is a great mini series... very informative .... loved it 👌🏻
Paul, thanks so much for shedding light on a very difficult subject to reduce. Years of theory and technological development reduced to a series of 45 minute talks is veeeery ambitious. My hat's off to you, Lee Anderton, for sponsoring these. Ok, so I have a pretty good understanding of the dynamics between the output transformer and the speaker motors (emf, back emf, resonance, etc). Paul, you made a point that that relationship has a great deal to do with the character of an amp/speaker system and that the speaker can actually provide for some of it's own boost in the lower and upper frequency ranges (impedance curves). Why can't that be applied to solid state amplifiers? Put in a sweet OPT? Cost? Defined design constraints? Weight?
Hi William, using an OPT in a solid-state amp has been done, exactly for these reasons - low damping. But you are right, the cost is the major reason to not use one. The OPT is the second, sometimes most, expensive single item in a guitar amplifier. However, the have been many attempts to create a similar low damping in other ways, such as current feedback. I'm glad you enjoyed the video. Paul.
@@Blackstaramps thanks for humoring me - I am quite sure, considering your line of work, that you have designed many methods for compensating or for creating a low damping factor. I also enjoy midfi audio as a hobby. In that application, we want a high damping factor for accuracy - having the amplifier "color" the sound is anathema. I will have to read up a bit on current feedback, especially as it applies to guitar amplification.
@@williamsmothers8830 Yes, guitar amps and hifi have two very different aims. In most of what I do I'm intentionally designing in colour and distortion. Guitar amps are musical instruments in their own way. Both are very interesting challenges though.
Very cool -- I learned a lot from this one! Many thanks, Paul.
Thanks, Paul. I didn't know that the output transformer of a tube amp was one reason why tube amps seem to be much louder than solid state amps.
What he's telling us is that an amps loudness is Voodoo Magic.
Paul explained this all really well, just had to rewind a couple times because he was going pretty fast. Interesting stuff.
Great video. Appreciated the technical level. It made a nice difference to the first video which was pretty basic.
this is why i LOVE my Rediron 5 Watter (really more like 8). i can play it at home or on a gig with the same 2 1x12 Ear Candy cabs (Eminence Texas Heat speakers) daisied with only just a volume control on the amp and use the vol and tone on the guitar to drive the amp. good job .
This was FANTASTIC!
This was a great video. It really explains many confusing topics. Speaker efficency is a really good thing to make people aware of. Its not all about the amp! The only thing I wish was explained better was why a valve amp sounds louder than a solid state with the same RMS power rating. This is something I've never technically understood, just accepted.
As someone looking into head and cab setups for the first time, this is pretty helpful.
Jacob Cardiff pro tip: don’t cheap out on the cab. Even if you get a really nice tube head, you’ll want a good cab to play it through. 👍
Great, helpful video. And I dig Blackstar amps. I have a 15 watt Fender Bassbreaker. I run it on the cleanest setting and put a great fuzzbox in front of it. It's more than loud enough to keep with with a very loud drummer I work with. Love it just fill the room. But I don't even have to turn it up loud. You work well with the soundman and put the mic in the right spot and it can be on 2 and it will sound like a wall of twenty Marshall stacks. I learned these tricks in my very early guitar career in the 80s when I started playing gigs on the Sunset Strip. I stopped lugging my Marshall stack and started using combos. I had a far better sound than any other players. The soundmen were always happy when I was giging because I was very easy to work with. I'd either use a Boogie combo, a Peavey, Marshall, or any number of Fenders I borrowed, like Deluxe Reverbs which are an excellent pedal platform. Don't get me wrong, a 100 watt stack has its place, but you can do most of what you need with a 20 watt, or in my case 15 watt amp. The speaker makes a big deal. I will not use anything but a 12 inch. As for brand, I keep an open mind. But 10 inch speakers just don't deliver.
@11:46 I did not know any of that! I’d thought it was because tube amps could start distorting (and therefore put out more power) without have as much of an audible effect as compared to solid-state amps. Neat!
Nice explanation, thank you Paul
This was very helpful. Thank you!
Great video - love this techy stuff!
Saying that cheaper speakers are less sensitive and more expensive are more sensitive is a pretty big generalization, some high end speakers are less sensitive, e.g. smaller magnet Celestion speakers like G12M Greenbacks and G12M-65s and similar, which are far from cheap.
@dsfadsfgafgf Greenback M 96dB, Greenback H 100dB, Creamback M 97dB, Creamback H 100dB. Bigger magnet = bigger magnet fields = more power handling (though the rest of the speaker need to support the power too) and generally more sensitivity. While magnet size isn't the only factor in sensitivity it is a pretty big one, often the reason a cheap speaker is not very sensitive is that the magnet is much smaller to save costs. E.g. celestion rocket 50 has a magnet about 1/2 the size of an M and only 95dB sensitivity.
The distorted channel of my Blackstar HT5-R (5w) is WAY louder than a Fender Mustang III (100w) and just about as loud as a Blues Jr. (15w) driven with a Wampler Sovereingn pedal... If that doesn't confuse you I don't know what does.
Great video series. I’ve learned a lot. If possible it would be great for you to talk a bit about attenuation, since many amps now have that feature built in.
Wow! Very informative and interesting!
Great job, Paul.
These Spinal Tap / Nigel Tufnel references are amusing. Maybe not surprising, I do come from the same part of London, Squatney.
Thanks again Capn!
Excellent video, thanks!
I like the explanation of volume relating to the increased frequency “content” when compression occurs. So, you hear more across the frequency range and perceive this as “loudness” (as opposed to actual measurable volume?). That’s probably why I like “clean” sounds until I hear them in a mix, when i want more “content” somehow. I guess the bottom and top is getting sliced off by drums?
Really excellent explanations. Those high price replacement speakers are really worth it! I wonder whether Nutube follows transistor rules or valve rules?
Great stuff. Thanks.
Very well done. Thanks.
Very educational. When the Captain said amps should just state “not loud, pretty loud, very f***ing loud,” I lost it, lol
Loved it! Thank you
Very very very interesting, thank you!
Fab video, really helpful.
Would like to know how you might expect tone and sound levels to change adding say a good 15 inch then a 12 inch and 10 inch speaker separately in cab under clean at unity settings. Then under heavy drive maybe with a good drive and or treble boost . Will sound (volume) stay same ? Will speaker size just change tone and just get fuzzier as speaker gets smaller? Would four 8 in. Or two 10in. In comparison not change response , tone or volume with same wattage out put amp , say at 100 watts . Thanks love this series as well as Justin's lesson's with the Capt. P.S. can 3 tree 16 ohm speakers be run safely at the same time with 8 ohm setting or go 4 ohm or not run 3 speakers at same time?
Paul the science guy ;) great video - thank you very much!
Much appreciated!
Thank you!!!
I NEVER knew that about SPL vs. Output power. Thank you! Very informative. BTW: I already own the HT Club 40 MK II. Does anyone have an opinion on the pre-loaded Cel 70/80? Would I really notice a sig difference in a V-30? Prob yes, but like to hear from someone who's done it?
I'm rockin' my Blackstar amp.
Great stuff!
when looking at the specs for an amp, I see the following:
Supply Voltage
Max Power Consumption
and
Output Power Rating.
Which of these 3 specs tell me how loud an amp will be?
I went back and paused the video at 00:21 just to re-read Paul’s credentials…yeah, I’m listening closely!
Worthwhile. Thx
What if you use an output transformer in a solid state amp? Would it eliminate the 2,5x volume diference?
YES LEE! We need the "Really, really, fffh( )kin loud." Label system!! xD
A 50-60 watt SS amp with one 12" super efficient (High SPL rating 98-99) speaker should be enough to gig with these days..just mic it up and you should be fine...
If not...check with you P.A. guy and your drummer :)
A 4 x 12 cab speaker pattern will tend to cause phase cancellation off to the sides making it extremely loud on axis. It is more of a "long throw" cab making them incredibly uneven at the front row although deafening to the person with the speakers pointing at their head. If you could fly 4 x 12 cabs and aim them towards the back half of the audience there would be less problems, although this is usually why it is better to run them at low volume and mic through a PA. At 1 watt, a 4 x 12 is already competing with a softer drummer.
I use a Vox Mini 5 at home and set to 0.1w. Sounds brilliant especially with distortion. Its got a 6.5" speaker.
Worth mentioning modelling amps too. Because the compression of the power stage is recreated digitally the actual power stage of the amp needs to be in its linear mode of operation otherwise it will colour the modelled tone so you lose a bit of effective power as you can’t take your power stage up to the point of clipping.
Interesting stuff. Same goes for audio fanatics.
Presumably somethings are changing as newer solid state amps appear to be getting louder?.... my Katana 50watt is bloody loud........👍🎸
Steve Bennett (adopts yorkshireman accent) eeh, amps were quieter in my day.....
I have an amp with clean and master volume. If I want to push the amp to break up but at lower volumes do I crank the master to full then play with clean volume or crank the volume and adjust the master volume? I can't find this answer anywhere on the interwebs.
So true heck my 1 watt Vox mini G2 amp is loud and even my 20 watt ENGL Ironball sounds massive and can get LOUD as heck on a 1x12 cab.
Great video, thanks for the info! I understood maybe 5% of this but it tells me that valve or solid state is important to consider and you don't need a $1500+ amp head and $1000 cabinet to perform live at a gig
Yea you do lmao
I like this series
In the valves vs. solid state part of discussion you didn't mention that the wattage rating is before distortion but when tube/valve amps turn up and distort they put out some more watts vs. solid state that just distort some more towards the full turn of the volume pot. That's why they say that a 100 watt Plexi cranked puts out 120 watts and you needed two 4x12 cabs in the old days when the speakers rated at 25 watts.
I still think that wattage is the "easiest" way to estimate the loudness. Why?
1) Bass amps usually have more watts than guitar amps because our ears are less sensitive to low frequencies, therefore need more watts to make bass louder.
2) When someone says 20watts can keep up with a drummer, they're usually talking about the cranked distorted sound. In my gigging experience, at least 50watts is needed for clean tones in small club gigs.
3) You would never use a 100watt in your living room because it's too loud.
4) This is an exaggeration, but FOH speakers in large arena concerts need thousands of watts for it to be loud.
5) A dedicated 1 watt amp can push headphones louder than the few miliWatts output of smartphones.
What's a speaker driver and can it be changed by switching out a speaker?
Thanks a lot for this (and for so many other interesting videos that you make at Andertons). I have a question: What about class D watts? My Bias Head (and also some Kemper models, I think) have a built in so called 600w class D amp. How much valve wattage does this correspond to? I'm asking because I'm using my Bias Head with my favorite 1x12 guitar cab, which has a Celestion G12-65 in it. It sounds very good, but I'm a bit anxious about how far up I can go with the volume on the Bias Head. I've been around halfway up with the volume on the Bias Head, and it doesn't sound louder than f.i. a Two Rock SP35 (which has the same speaker) with the volume halfway up. (I'm talking about more or less clean sounds.) So it's tempting to believe that the wattage on the class D amps is only a tenth worth of the wattage of a valve amp, or something like that. What's your opinion? (PS. I'm playing my Bias Head through a real guitar cab because it sounds way better than the cab sims through an FRFR cab.)
Class D is different again. Obviously the main advantage of Class D is the improved efficiency which mainly means that more power can be generated for less weight. However, in my experience, Class D amps are often rather enthusiastically rated. They sometimes can't put out their rated power continuously and they certainly do not like to be pushed beyond their rated power; the distortion is not pleasant. It is for these reasons that often circuitry needs to be designed in to add a soft-clip before the nasty limit is reached. This will mean the real clean headroom has to be limited but this often isn't reflected in the published specifications. So, bearing this in mind, IMO, I would assume a Class D amp rated at a certain power can probably be assumed to effectively be around 1/2 to 2/3rds of that in the real world. Not putting Class D down at all, but just like valve v SS, the rated 'watts' are not the only thing to consider. Of course each amp is different so I couldn't accurately comment on this particular one unless I'd had it on the bench to test. Hope this helps, Paul.
@@Blackstaramps Thanks a lot, Paul. How nice of you to take your time to answer. You guys are really generous! Thank you!!! :-)
Would love to see some of the difference volume levels there is with the blackstar range, like for example thr 1w head, the 5w head the 7w fly, the 10w I'd, 50w combo 50w head, 100w, so on so forth, even if it's just a few of them, because I'd be super interested as I love blackstar, am an avid fan but have never heard any of them go head to head volume wise
that guy sums up DBSPL as a champ! grats!
This is probably the most important/misunderstood topic for buyers and you took a fair crack at it!
At the start, Paul looks like he will break down any second
Yes I think he could have used a stiff drink before this. Or Lee could have put him a bit more at ease! Poor chap.
These videos get like a million views each bruh. I wouldn't be able to do it!
Antilevitation But he did a brilliant job👍🏻
I can't deny that! It's not an easy subject to explain to people
Ha ha! I must admit I was a bit nervous. I've known Lee a long time but I knew how many views this might get. This was fitted in between normal design duties and, apart from some basic suggested questions, the rest was improvised. We only did one take for anything as well. Thanks for watching. Paul.
Awesome video!!! We should get rid of marketing watts hahaha. Also claret and blue make me think of two teams, either Aston Villa or West Ham, which one would it be?
I love my Blackstar amp.
Again id still like to know some about how amps have changed over the years gain wise. And how do they achieve the types of gain used in today's lets say metal music and such with just using nothing but tubes. I have seen all tube amps with 12AX7s as pre tubes and the amp is clean as heck . How has technology changed in relation to getting such high amounts of gain from the same tubes that have been used since the start and does this wear out the pre amp tubes faster?
Speaker Sensitivity ... and how many of them .... without that, wattage means nothing in and of itself.
but good mention of compression.
i have a 40 watt solid state amp, hot rodded the speakers, but when i started adding pedal compression, it was like going from 114db to pushing 120db ( Tech 21 Mop Top Liverpool )
I wish you guys had covered series vs parallel wiring of cabs. I'm not finding much info on the tonal effects of each. My Vox uses two Celestion speakers at 8 ohms each in series for a 16 ohm load. The DC-30 uses two at 16 ohm in parallel for an 8 ohm load. WHY!?
What about corelliation on watts consumption and watts produced as sound on valve amps and solid state amps. I think ht1 amp needed 25 W power to produce 1 W sound.
I really enjoy hearing a subject matter expert explain things they are passionate about. Even if I have to stop and look at the glossary occasionally.
This was fantastic, Capt.
Question @Blackstar if you gentlemen are still monitoring.
I'm from the US and I seem to have difficulty procuring any of your valve amp heads loaded with 6L6 tubes instead of EL34. In fact the only ones I seem to be able to track down are HT series amps and pretty much nothing else.
The website seems to still showcase them, and no mentions of discontinuation that I can find. Are they out of production or are they simply not available in the US anymore? And if so, any plans to bring back 6L6 powered valve amps our way? Thanks!
We do offer some models of the Series One range specifically with 6L6's However, the latest HT Venue range can also be biased to work with them as well. Why is it that you want 6L6 over EL34?
@@Blackstaramps Series One 1046L6 has always been a head that catches my eye, tho the large retailers and online outlets can't ever seem to get them. I mostly assumed they just weren't going to come around anymore.
Why 6L6 over EL34? Well it's hard to put into words really since it's always about sounds but I will try my best. Mostly it has to do with the more "modern" tone they seem to more reliably produce. Coupled with the fact that I also play 7 and 8 string extended range guitars, I feel the 6L6 compliments those ranges much better then EL34. Feels more... "present" and really helps to make them stand out.
Hopefully, that sort of describes it for you. Thanks for the response!
Awesome...let's have more of ScienceGuy Paul ......:)
hi from eastern Canada ... thanks for the vid, as always
Love my fender mustang gt 100 at any sound level
I was wondering if you could do a video that would explain the concepts of gain and distortion. How do you contrast gain and volume and how do they relate to distortion. Is distortion a function of gain or are they entirely different.
I am hoping for that too.
Not only is Paul a top amp designer he's also a tremendous guitar player. When are you coming to sort out my Club 40 Paul? ;)
Geoff Floyd - You're not my old Physics teacher are you? He was one of the reasons I ended up doing what I do.
Of course it's me...... remember we made contact on Facebook not so long ago! Nice video.... been a fan of Andertons for ages. You still got that silver 25th anniversary Strat?
take your 1W/1M speaker sensitivity, add 3 per doubling of speakers.
then count up to your wattage 2, 4, 8, 16, 32, 64, 128 but stop short of your wattage and count, ( eg 32 watts for 40 = 2, 4 , 8, 16, 32 = 5 ) then you take that number, ( eg. 5 ) x3db = ( eg.15db ),
then add that to your 1W/1M speaker sensitivity = max RMS db
that put me at 114 to 115 db ... barely adequate i thought ...but like he says, compression really punches it up....i basically added a solid state "tube amp", and Wow !!!
You probably have already recorded all the videos, but I would've liked to know more about speakers interacting with amplifiers. Say in terms of using different wattages, sensitivities, combinations of speakers, and so on. - Though that might still be possible for a later videos as it's not exactly about "amplifier myths" that. - But I'm trying to pick new speakers for this particular amplifier and I can't for the life of me choose from even just four slightly different ones.
the maths is fairly simple, you double the output power for a 3db increase in output (until power compression kicks in, which basically means the gains start to roll of as you approach the rated power of a driver, as more and more power gets wasted as heat)
Unfortunately guitar amp output power is kind of clear as mud as they were alluding to, the real world output (in watts) you're going to get is going to depend on how much you are going to distort and compress the signal within the amp. usually in the PA world, we would be using 0.1% THD as the maximum allowable distortion when measuring a power amp, but thats not really helpful for a guitar amp, where the distortion is a key part of the output sound, rather than an annoyance.
as for impedance, we usually deal with 'nominal impedances'' where speakers are concerned, this is kind of the average impedance over the usable frequency range, but is by no means constant. In short, a lower impedance driver resists the current from the amplifier less, and using V=IR and P=IV, you can know that power in watts will be higher from a given amp into a lower impedance load than a higher impedance once (although, this doesn't apply to the transformer taps on a valve amp, as they will regulate the output voltage to ensure that the valves aren't run too hard).
as for combinations of driver, for drivers wired in series, you add the impedances together, and for parallel wiring you add the inverse (the 1-over) of the impedances together
Drivers are usually designed to work over a limited frequency range, and will usually roll off in the high and low end,
Doubling the number of drivers will give you an approximately 3db increase in volume, although, the spacing of the centres of the drivers relative to the wavelength being reproduced may make this less, typically this means that lower frequencies will benefit more from adding drivers whereas higher frequencies will not get as much benefit (and be more directional in the first place)
Wattage is measured by the maxium volume the amp can be turned to without the waveform distorting.
That means the amp can still get louder, but not with a clean signal.
So 2 amplifiers both rated at 15 watts could have different volumes because one may break up later than the other.
How about the difference between Class A, class AB, etc. amps?
I'm still trying to perfectly dissect the relationship between the amp's and speaker's, ohm and wattage friendship with one another, and now we're introducing volume and sensitivity to the equation?!
I'm pretty certain I just blew a few brain cells!
Do you lads offer repair service on that kinda thing?
The Captain was getting that look similar to when Justin is explaining music theory