Ways to fry an Amplifier?

[audioguru]

It is best to use an active highpass filter for the mid-bass and higher frequencies amplifiers and use an active lowpass filter for the subwoofer amplifier.
Linkwitz-Riley filters are the best.

I think adding two power transistors to the power supply rails of a little TDA2030A amplifier IC is a Mickey Mouse way to cool the IC but it works. The output power is not much higher than an ordinary car amplifier IC and it needs a complicated switching power supply.

Philips has some class-H power amplifier ICs for cars that have a built-in supply voltage doubler. Then it switches its supply voltage to the output stage to the boosted voltage only when required to stay "cool" (so it doesn't melt). Their TDA1562Q produces 55W into 4 ohms at 0.5% distortion when the supply is 14.4V. the power is 45W when the supply is 13.8V.

Good luck making your own very complicated switching power supply for the other amplifier ICs.

 

[Nigel Goodwin]

You can hear better bass in the cabin of a car due to the cabin effect that makes low frequencies louder down to the lowest frequency of the subwoofer which is about 16Hz. of course you can hear them and feel them.
Standing waves add as well as cancel at some frequencies. Most low frequencies have the same phase all over the cabin of a car so they do not cancel.

Hardly 'better' bass, you get a single note thumping that rattles everything, decent bass would be smooth and wide ranging.

 

[Peter_wadley]

Do you think I would just be better off buying ... say this one:

**broken link removed**

And buy a 300W 4OHM sub?

Would it provide the thumps Im looking for?

To brige it ... im I correct to think...

Connect the negative lead of the sub to the negative terminal of channel 1...
Connect the positive lead of the sub to the positive terminal of channel 2...
Short the positive terminal of channel 1 with the positive negative terminal of channel 2...

do this to both the input and outputs?

Is 10 gauge wire enough for this wattage?

thanks

 

[audioguru]

Future Shop does not have detailed spec's for the Exile 300.2 car amplifier.
But the owner's manual is in Google:
The manufaturer also does not provide detailed spec's. No mention of which kind of Whats or Watts. Not a word about distortion.

It has a 25A fuse. 25A x 12V= 300W.
The owner's manual says it is 50% efficient. So 150W of heat and 150W of output power maybe when it is turned up way too loud and produces horrible distortion. Maybe its output at low distortion is only 100W (or less).

Your description of connecting the subwoofer to a bridged amplifier is a dead short circuit to the amplifier. The + terminals of the amplifier are the connections to the speaker. The Bridging switch (is not shown in the owner's manual) combines the two channels and inverts one. Read how to connect the speakers in the owner's manual.

 

[audioguru]

Hi Nigel,
I have seen and heard cheap car speakers with see-through plexiglass that rattles. The speaker driver is cheap and the enclosure doesn't match it so it makes one-note bass.

I have also seen and heard excellent car speakers that have very wide-range and smooth response. My 10" ported subwoofer is in the trunk of my car and has a 200W RMS amp. Its response is very wide-range and smooth. When some music plays a downward scale of bass and it reaches 20Hz then continues farther downward, I get goosebumps when I cannot hear it anymore but feel it strongly.

 

[Peter_wadley]

Your description of connecting the subwoofer to a bridged amplifier is a dead short circuit to the amplifier. The + terminals of the amplifier are the connections to the speaker. The Bridging switch (is not shown in the owner's manual) combines the two channels and inverts one. Read how to connect the speakers in the owner's manual.

Thank you for clarifying!

When some music plays a downward scale of bass and it reaches 20Hz then continues farther downward, I get goosebumps when I cannot hear it anymore but feel it strongly.

Can't wait to expierence something like that!!

It's apparent I need to do alot more research .. guess you just cant go cheap on this type of project!

 

[audioguru]

As Nigel says, a cheap subwoofer produces one-note bass (at about 100Hz).

 

[rjvh]

No.
an 8 ohm speaker has a minimum impedance of 8 ohms just above its low frequency resonant frequency. Its impedance rises at high frequencies due to its inductance. Its resistance is about 6 ohms at DC.

this is treu in theory but it will be greatly affected if by the casing you put the speaker in to (if you put it in a enclosed housing its not a problem but if you put it in a poor designed base reflex housing you get much lower valey's in your impendance)


No and no.
PA equipment is made to be efficient (loud with low power) not to produce very low bass frequencies.

Pa systems are loud with low power :gtoet: 94 db a watt normaly
the poin't i want to make clear was that if you want to feel instead of only hearing music it takes more power than people do aspect

Powerful car amplifiers don't need extra car batteries, they use a switching power supply to boost the supply voltage.



No.
You can hear better bass in the cabin of a car due to the cabin effect that makes low frequencies louder down to the lowest frequency of the subwoofer which is about 16Hz. of course you can hear them and feel them.
Standing waves add as well as cancel at some frequencies. Most low frequencies have the same phase all over the cabin of a car so they do not cancel.

I my opinion and what i 've learned is that you can only hear tones in a room if the complete lengt of the wave can be represented in that room
other wise you can only feel the energy but not hear

cabins do give normaly a amplified effect to some of the tones due to the pressure that build up in it and standing waves still i consider that as a distortion over your tone balance this (distortion) is also frequency depended (it's set by the volume of the room/cabin)

canseling out is only a biger problem if you still have other speakers in the same room/cabin that are not properly filtered In this case to the low side(of course the speakers have to be able to produce those frequentys in the first place)
Robert-Jan

 

[Peter_wadley]

Lets say you have an amp that can output 100W...

if you load that amp with an 12" 300W 4hm: speaker...

and then (at different time) you load it with say.. an 12" 600W 4hm: speaker...

Would the load look the same to the amp?

Is the wattage of speaker just a max for the wattage they CAN take or is it what they are going to TRY to take from the amp?

 

[rjvh]

the load for the amplifier would be the same (there might be impendance differences on various frequencys as there are differences in the impendance curve between the different speakers )

Robert-Jan

 

[audioguru]

Are you talking about a speaker that is rated at 100 Whats or 100 Watts? There is a huge difference.

Just like with amplifiers.
Only continuous RMS power at a specified low distortion is real power. The others are "peak power", "maximum power", "music power" and all kinds of other lies that make the number much bigger than real power.

 

[Peter_wadley]

Only continuous RMS power at a specified low distortion is real power.

Understood sir