I have a small 2.1 plate amplifier that is unhappy at being matched to a 3 ohm driver. I plan to buy a power resistor after the holiday. In the mean time can I test using a 5w 4ohm resistor?
Will I damage anything? The amp is 20 watts RMS.
Will I damage anything? The amp is 20 watts RMS.
It's not entirely certain that the amp will have a problem, but assuming you did put a resistor in series, the response is going to be a little different.
No, you will not damage anything, at normal listening level, there is likely less than a watt. No harm in testing.
If you need to run it full power all the time, something is not right, resistor may get hot and burn. Still no harm to plate amp or speaker.
If you have four of those 4ohm 5watt resistors, put them series/parallel for 20 watts power handling.
Please define "unhappy".
What is the audible symptom?
At 50% volume the driver begins to 'pop', any higher and the and the amp starts cutting out.
What is the audible symptom?
At 50% volume the driver begins to 'pop', any higher and the and the amp starts cutting out.
Sounds like clipping and protection kicking in.
Some products only pretend to produce what the are specified.
I have chinese amp specified as 300 + 300 watts. It has one 4 x 7 watts chip in it. Bridged to stereo.
Some products only pretend to produce what the are specified.
I have chinese amp specified as 300 + 300 watts. It has one 4 x 7 watts chip in it. Bridged to stereo.
I don't have much in the way of test equipment but I have the world of random components to test with. The amp works okay with 6 ohm and 8 ohm drivers.
The amp claims 15w + 5w (x2) RMS . The PSU offers 2.5a @ 12v. So I guess the output claims are fairly genuine.
The amp claims 15w + 5w (x2) RMS . The PSU offers 2.5a @ 12v. So I guess the output claims are fairly genuine.
As low bass frequencies draw more current from the power supply than the higher frequencies in sound reproduction, inserting a bipolar electrolytic of 470uF in series with the 3 ohm speaker will attenuate those very low frequencies while maintaining a higher output at higher frequencies. You will need to experiment with that value for the best balance.
C.M
C.M
Those are two very different statements,you should have said so from the beginning.
Ok, that hints at 4 x TDA2003 or equivalent, same as adason´s
in your case and with that supply: 2 sections bridged for 15W into 4 ohm (so 3 ohm is just within capability) plus 2 x 5/7W sections into 8/4 ohm
The bare minimum for a 2:1 system but still usable, I have made many similar systems for friends as Birthday or Christmas presents 🙂
Amp "should" work, although we ignore which chipamps it uses (maybe you can post a gut picture showing them) but I find the PSU somewhat underrates, specially if they were "optimistic" with its ratings.
Is it a switching mode PSU?
It might be self protecting and cutting power to amp at critical moments, that certainly sounds horrible.
Show a picture too, what does its label say?
My point being that maybe you do not have a *speaker* problem per se but perhaps a supply one.
"Most" 12V specified chipamps intended for car radios and such are designed for 4 ohm loads and can take a 3 ohm speaker.
Again, we do not know what chips does yours use, a searchable part number might lead to a datasheet 🙂
As there are no high frequencies passing through the amp. I don't think your advice is helpful.
"As there are no high frequencies passing through the amp. I don't think your advice is helpful."
Well, you are not being particularly helpful in not giving any details as to how your speaker is connected or as to what it is. Is it a subwoofer ? or a fullrange driver ?
To what output channel is it connected ?
C.M
Well, you are not being particularly helpful in not giving any details as to how your speaker is connected or as to what it is. Is it a subwoofer ? or a fullrange driver ?
To what output channel is it connected ?
C.M