Tuesday, January 31, 2006

Vukovic


Last Saturday I attented my first ever bass guitar class. Well, not actually a bass guitar class since I was the only bassist of the class (the rest being guitarists). It's surprising to find out that even after around 4 years of playing bass I still have space to brush up the very basics. I'm speaking about the posture and correct fretting/plucking hand technique.

That's what we basically focused in the class - fingering exercises (combination of using two fretting fingers 1-2, 1-3, 1-4, 2-3, 2-4, 3-4 and in reverse).

I also learned a new plucking hand technique which I'm beginning to adopt - it basically consists of resting the thumb on the string in top of the other string I'm plucking. I know this all sounds confusing, but the concept is that the thumb shifts with the plucking hand in contrast to the traditional 'place your thumb on the pickup'. This will allow more possibilities in your bass playing especially increasing plucking speed.

January hiatus

I apologize for not warning you all about the hiatus. The main reason is that the real world has actually been consuming all of my time.

It's funny that I seem to differentiate between blogging and the real world isn't it? It's not as if blogging is something that happens outside of reality. Hmmm, that's definitely something to think about for a later post.

Anyway, for all of you who read this blog to find out about me and my adventures, I should probably write a bit about what I've been up to for the last month or so...

But let me tell you being away from the computer makes me realize what an email junkie I am.

Thanks for your patience.

Sunday, January 01, 2006

Joe Osborn

After many and many research, I've finally discovered who is the virtuoso bassist who made the bassline for the pop 60's song Aquarius/Let The Sunshine In, sung by the 5th Dimension. Joe Osborn, born in 1937, though little known to the public, Osborn's work is widely admired by fellow musicians.
















This old guy is solid as a rock. He kicks ass. Joe Osborn's instrument throughout most of his recording career was a 1960 Fender "stack-knob" Jazz Bass. His style is distinctive, with a resonant, bright tone produced, in part, by his use of a plectrum (pick).

Many producers and arrangers chose to spotlight his contributions by mixing the bass line more prominently than had been customary, and incorporating brief bass solos into their arrangements. His playing can be readily heard on records by such well-known groups as the Mamas and the Papas, the Association, and the Fifth Dimension. Osborn's contribution to Simon and Garfunkel's "Bridge Over Troubled Water" is particularly compelling, but his best-known creation is probably the funky obbligato that powers the Fifth Dimension's version of "Aquarius/Let the Sunshine In."

It is safe to say that if you were listening to the radio in the '60s and early '70s, then you were listening to Joe several times an hour, all day long. Some of Osborn's fondest memories from that era took place in a recording studio he built in the garage of his North Hollywood home. Joe worked with a variety of young, would-be stars in those days, including Jan & Dean, Ry Cooder, Taj Mahal and Kenny Rogers. It was there he recorded the young, undiscovered Karen and Richard Carpenter; he began developing his signature upper register bass lines and melodic slides while playing with them. " 'Let the Sunshine In' is probably one of the most talked about bass lines," Osborn said, "but one of my personal favorites is The Carpenters' 'For All We Know.' " Throughout this song you can hear the Osborn-original creative slide technique.

Reference: Wikipedia

John Deacon

John Richard Deacon was the bassist for the rock band Queen, playing rhythm and acoustic guitars in several of their albums as well as ocassional keyboards. Born 19 August, 1951 in Leicester, United Kingdom, he was the youngest member of Queen. He is the author of the hits "Another One Bites The Dust" and "I Want To Break Free", which show that his contribution to Queen was significant. Deacon is also the only member of Queen never to sing on any of their tracks, although in music videos it appears that he does.



Deacon is not just one of my musical influences, but also a personal influence as I endorse his same philosophy. He was the 'quiet' member of the band, and the others said that he was in charge of most of the finances. His last public appearance with the band was at an AIDS Charity event in 1997, and his last direct involvement with Queen, was with the recording of No One But You. He lives in South-west London with his wife Veronica and their five sons and one daughter. John occassionally visits the Queen fan club to keep up to date with the world of Queen but remains an elusive character. He enjoys drinking tea, playing golf, and music wise "likes a bit of everything". According to The Sunday Times Rich List he is worth £50 million in 2004.



As a trained electrical engineer, he often used to jimmy up equipment for the band. His most famous creation is the "Deacy Amp", used by Brian May.

Preamplification

I'm really sorry that lately I'm boring some of my readers with technical and musical stuff :) I promise that I will compensate for that in future posts, but at the moment let me tell you that I'm using again my beloved Behringer Bass V-Amp, which is a very interesting instrument preamplifer.




My favorite presets are:
E2 - Normal/Slap Bass
D2 - Overdrive
B1 - Chorus/Solos




I connect it in Live Mode L3, meaning that I connect the left channel to my amplifier and the right channel to the mixing console.

Power handling pt.3

In this post I will recapitulate what we have learned from the previous two posts. I will use my rig as an example:

- Behringer 3000T 300W @4ohms Bass Head
- Behringer BA210 500W 8ohm Cabinet (2 x 10")
- Behringer BA115 600W 8ohm Cabinet (1 x 15")

First things first...We need to calculate the maximum distortion-free output voltage of the amplifier, Vs. This is a constant parameter which depends on the amplifier characteristics (output power and internal impedance). From the above info, we can say that if we connect a 4ohm load to the amplifier (match impedance with impedance of amplifier). the delivered power (power on the load) will be 300W:










P out = (I tot)^2 * (Z rig)
300 = (I tot)^2 * 4
=> I tot = 8.66A

But, Required Power (power driven from amplifier) can be found from:
P req = (I tot)^2 * (Z tot)
= (8.66)^2 * (4 + 4)
=> P req = 600W


Referring to the above diagram, the maximum distortion free output voltage can be found from:

Vs = (P req) / I tot
= 600 / 8.66

=> Vs = 69.3V

Now that we have calculated the maximum output voltage of the amplifier, we can solve the puzzle:

How much power is delivered/required if I connect both the Behringer cabs?
With both Behringer cabs connected in parallel, we will have a total impedance of 4ohms. We will basically end up with the same circuit in the first diagram. Therefore we know that total current is:

I tot = 8.66A

Therefore P out = (8.66)^2 * 4
=> P out = 300W

and, P req = (8.66) ^ 2 * (4 + 4)
=> P req = 600W

How much power is delivered/required if I connect only one of the Behringer cabs?
With just one cab connected to the amplifier, I will have an 8ohm load across the amplifier. Using the same equations together with the popular V = I * R:

I tot = Vs / Z tot
= 69.3 / (4 + 8)
= 5.77A

Therefore P out = (5.77)^2 * 8
=> P out = 267W

and, P req = (5.77) ^ 2 * (4 + 8)
=> P req = 400W

How much power is delivered/required if I connect a 4ohm cab to my rig?
We are now presenting a load total of 2ohm to the amplifier. More current will flow compared to the previous scenario, so we are driving the amp harder, risking to blow it up. Using the same equations once again:

I tot = Vs / Z tot
= 69.3 / (4 + 2)
= 11.55A

Therefore P out = (11.55)^2 * 2
=> P out = 267W

and, P req = (11.55) ^ 2 * (4 + 2)
=> P req = 800W

Now comes the final question. Let's depict it by using a complex scenario. Assume that my 2ohm rig is connected as in the below diagram.








Will each cab be able to handle the power being presented to it, assuming that the cabs have a maximum handling power of 500W each?
From the previous step, I tot = 11.55A. This means that the voltage drop in the amplifier's internal resistance is:

Vd = I tot * Internal Resistance
Vd = 11.55 * 4
Vd = 46.2V

Thus, the voltage across rig,

V ld = Vs - Vd
V ld = 69.3 - 46.2
V ld = 23.1V

Therefore, using the formula Power = V^2 / R:

P1 = 23.1^2 / 8 = 66.7W
P2 = 23.1^2 / 8 = 66.7W
P3 = 23.1^2 / 4 = 133.4W

This means that all of the cabs will handle the power delivered to them.
Note that if you sum all the power delivered per speaker, you will obtain the total delivered power. This shows that power is an additive quantity, whether the load is connected in series or in parallel. In layman's words, if I have a 300W sound system with two similar speakers (in terms of impedance), I will have 150W delivered from each speaker.