Design bass amplifier

[Sunnysky]

I knew that a TDA2030 was obsolete but today I am surprized to see that the TDA2030A is also obsolete. If you can find one then 12V is its minimum supply where its output to an 8 ohm speaker is only 2W or 3W. The power vs supply voltage graph in its datasheet begins at 24V where its power into 8 ohms is 6W.

What do you suggest for others to use as a replacement? LM3886?

 

[Audioguru]

An LM1875 is still made and is similar to a TDA2030. Its minimum supply is 16V producing about 4W into 8 ohms.
Maybe 10W is better then the supply can be 30V.
An LM3886 is nice with a 70V supply and an output of 50W to 62W into 8 ohms.

 

[josejos]

Ok, thanks this solved my problem with the spice model.

I have built the filter and the 50Hz noise is almost gone at the output.
The 200Hz signal is my input signal.

But they still sell the TDA2030?
I tought to use 2 TDA2030 as a bridge amplifier for the subwoofer and for each tweeter a TDA2030.
Is this a good idea? , can i still use a bridge amplifier for the subwoofer because the impedance is only 6ohm.

 

[Audioguru]

Digikey is a large American electronic parts distributor. They say the tDA2030 and the TDA2030A are obsolete and they have none.
A 6 ohm load causes double the current in a bridged amplifier so each amplifier must be able to drive 3 ohms.
An LM3886 amplifier IC is available and can drive the 6 ohm woofer to 55W with a 56V supply or 82W with a 70V supply but it needs a huge heatsink.

Your Japanese sound system has a small 6.5" woofer, not a big subwoofer. Its spec's say it barely produces 40Hz at -10dB (not much sound) so it will probably produce woofer sounds down to 80Hz, not subwoofer sounds.

 

[bushtech]

Yep. My common sense says: Sub woofers are big mothers in a box. 6" Speaker is something you find in a car door = mid range

 

[josejos]

Ok thanks, i consider to use another speakers for the application?
Do anyone have experience with class D amplifiers?
I would like to use these because there good power efficiency.

 

[Audioguru]

Some class-D amplifiers are pretty good. Others are cheap, make bad sounds and are low power.

 

[josejos]

I found the TPA3116 as amplifier, it seems a good one with many options.
What is your opinion about this chip?

 

[Audioguru]

The TPA3116d2 amplifier produces 20W per channel at low distortion into 8 ohm speakers when the supply is 20V.
It produces 20W per channel at low distortion into 4 ohm speakers when the supply is 14V.
A small heatsink is needed but I do not know how to mount it and I don't know if you can solder to all those tiny little surface mount pins.

 

[WHONOES]

Yep. My common sense says: Sub woofers are big mothers in a box. 6" Speaker is something you find in a car door = mid range

I disagree, 6" speakers can be used for Sub Woofers. The units I used in my Hi-Fi are 6.5" diameter. The -3dB response is 33Hz and produce enough bass to rattle the windows. It is just a case of choosing the correct, or should I say, appropriate speaker chassis and loading it correctly.
As for class D amplification, I would avoid it for a first build and stick to a class AB or B for simplicity and, in my opinion, a better sound.

 

[bushtech]

Whonoes, correct it can be used to create a sub woofer. I was generalising. But for creating a sub woofer your first choice of speaker will not be a 6 incher. Much easier making a decent sub woofer with nice tight bass out of a 10 incher.

 

[WHONOES]

Yes, but I can get nice tight bass out of a 6" unit. As I said it is just a case of picking the correct unit and loading it correctly. Have been doing it for a long time.

 

[Audioguru]

The spec's for the Panasonic home theater 6.5 inches in diameter "subwoofer" say 141W with 1% distortion at 40Hz to 198Hz (-10dB). But at -10dB it is barely working so it is NOT a subwoofer and is not even a good ordinary woofer.
ALL the speakers for this home theater are 6.5" in diameter. The front speakers, the surround speakers and also the center speaker.

 

[WHONOES]

I agree with you, the spec on those units is not very good but, they are not the only 6.5" drivers on the planet. There are numerous units that will easily outperform them.

 

[Audioguru]

He is using those lousy speakers.

 

[WHONOES]

Perhaps we should encourage him to use something else!

 

[Audioguru]

I have a clock radio in the bedroom. Its 3" speaker sounds awful so I connected a Radio Shack enclosed 2-way speaker I modded to it and it also sounded awful. I increased the values of the radio's coupling capacitors and now it sounds great. I modded the speaker by throwing away its garbage cone tweeter and used a high quality Seas dome one, made a good crossover network and added a port that allows response down to about 40Hz. The woofer is a high throw low resonance 6.5" one.

 

[bushtech]

Now that's the kind of mod I like! Silk purse sow's ear stuff.

 

[Audioguru]

Now that's the kind of mod I like! Silk purse sow's ear stuff.

The Radio Shack enclosed speaker had a really good 6.5" woofer probably designed for a ported enclosure but it was in a sealed enclosure producing bongo drum resonance sounds. The tweeter was very cheap and sounded awful. When people heard their awful sounds in the store then none were sold so they went on sale at a very low price. I am glad I bought them at a low cost and modded them.

 

[josejos]

Perhaps we should encourage him to use something else!

I recently searched for new speakers but there are so many speakers around.