Bass Box

[Mukhalled]

Hi guys 

I want to make an amplifier for the bass box in my car (eg 100W). Can you recommend one of the circuits here, or you may have another one in another place  ;D

Thanx

 

[audioguru2]

Hi Mukhalled,
The amp must match your bass box's speaker or speakers.
How many bass speakers and what is their impedance?
How much true power do you want?

Many amp circuits would be suitable if they operate well in the temperature extremes of a car. The problem you will have is making a supply voltage stepup circuit.
For an 8 ohm speaker to produce 100W, it must have a voltage swing of 80Vp-p across it. Therefore its amp must have a power supply of about 90V, or positive and negative 45V.
A 4 ohm speaker needs a voltage swing of 56.6V, so its amp would need a supply voltage of about 64V or positive and negative 32V.

Here is a voltage step-up circuit for a powerful car amp:
http://www.sound.westhost.com/project89.htm

 

[Mukhalled]

Hi Audiogu,
The bass box has one speaker of 6 ohms (60W i think) its not so powerful but its enough for me  ;D. I think 60W-100W amp will do well. There is a low-pass filter into the box so i think i need only a power amp, right?

 

[audioguru2]

The bass box has one speaker of 6 ohms (60W i think) its not so powerful but its enough for me

 

[Mukhalled]

okay. I have another question, can i use two power amplifiers and only one preamp. as you know Audioguru i've built a complete audio amp (preamp and power amp). these circuits i used below:
Preamp: http://www.electronics-lab.com/projects/audio/039/index.html
Power amp: http://www.electronics-lab.com/projects/audio/006/index.html
and i want to add this amp, (can i take signals from the output of the preamp, i mean one preamp to two power amps)?  ???
this is the another amp:
http://www.ortodoxism.ro/datasheets/nationalsemiconductor/DS005129.PDF

thanks

 

[audioguru2]

Hi Mukhalled,
The LM2005 amp doesn't have enough power for your 6 ohm bass box. It will be only about 10W at clipping when its amps are bridged.

The preamp has low impedance outputs therefore can drive many amplifiers. Use a 10k resistor from each output of the preamp to the capacitor at the input of the LM2005 amp, so that the bass box will play bass from both stereo channels. 

 

[Mukhalled]

Hi Audioguru

 

[Mukhalled]

Hi audioguru,
Do you mean i will connect like this: ;D  (isn't it short?  ???)

View attachment 38647

 

[prateeksikka]

hi audioguru!
we often see the concept of virtual short b/w the 2 input terminals and we also see that both are at near ground potential.

het wait if that is the case,where is the signal to be amplified????
pls tell me...
:

 

[audioguru2]

Yes i know the LM2005 has no enough power

 

[audioguru2]

hi audioguru!
we often see the concept of virtual short b/w the 2 input terminals and we also see that both are at near ground potential.

het wait if that is the case,where is the signal to be amplified????
pls tell me...
:

The signal causes a current in the input resistors. The inverting amplifier with the virtual ground input creates the same amount of current current to flow in its negative feedback resistor which causes amplification of the signal.

 

[Mukhalled]

Hi audioguru and everybody,
Should i connenct pin 8 and pin 6 to Vp as i drew? and what is pin 12? ??? where should it be connencted?

Thanks

View attachment 38661

 

[audioguru2]

Should i connenct pin 8 and pin 6 to Vp as i drew? and what is pin 12? ??? where should it be connencted?

The datasheet for the TDA1516 doesn't say much about its bootstrap pins but you are not using them so they should be connected to the positive supply Vp as you show. The datasheet says what to do with pin 12 when bootstrapping is used but doesn't say what to do without bootstrapping.

This amp is just about the same as the LM2005. It produces 22W into a 4 ohm speaker at 10% distortion with a 14.4V supply.  The LM2005 provides 20W under the same conditions.
With a 12V supply they will both provide about 10 Watts at clipping into your 6 ohm speaker.