Amplifier Question!! How much power can my amp provide?

[themisPlayer]

Hello, I want to ask something about my old Cassette Tuner Amplifier -> Rotel RCX-820.
I'm currently using it for my pc set up and I can say it handles everything ok, but I would like to upgrade the audio setup with an extra Woofer (to increase the Bass)

Power output: 20 watts per channel into 8Ω

How big woofer can I try to fit with this Amplifier?
And if you know any good Woofers I am open for suggestions!
Thank you!

 

[hang-the-9]

Hello, I want to ask something about my old Cassette Tuner Amplifier -> Rotel RCX-820.
I'm currently using it for my pc set up and I can say it handles everything ok, but I would like to upgrade the audio setup with an extra Woofer (to increase the Bass)

Power output: 20 watts per channel into 8Ω

How big woofer can I try to fit with this Amplifier?
And if you know any good Woofers I am open for suggestions!
Thank you!

Your question you answered yourself in the post, 20 watts.

For a sub with that system you will need a powered sub with a cross-over something similar to this https/www.newegg.com/Product/Product.aspx?Item=N82E16882290034&Tpk=N82E16882290034 Line out on the stereo will go to the sub, the smaller speakers will go from the sub.

 

[themisPlayer]

Actually I forgot to mention something, I have already connected 2 Speakers (each has) 8' Inches Woofer with a tweeter (50 watt woofers and the tweeters I don't really know, they are custom made).

I'm not an expert but the Amplifier says max -> 20 watts and I have already (2x)50+ watts on it and it is perfectly fine.
So my actual question is how much watts can I put on this Amplifier without burning it down (extra watts with the current ones)

 

[hang-the-9]

Actually I forgot to mention something, I have already connected 2 Speakers (each has) 8' Inches Woofer with a tweeter (50 watt woofers and the tweeters I don't really know, they are custom made).

I'm not an expert but the Amplifier says max -> 20 watts and I have already (2x)50+ watts on it and it is perfectly fine.
So my actual question is how much watts can I put on this Amplifier without burning it down (extra watts with the current ones)

Your speaker wattage rating is the max you should use on them without blowing the cones. Has nothing to do with what your amp is running as a load. You are not putting watts on the power supply, it's just how loud and clear the speakers will run, and some speakers do not work well on low power amp, that includes subwoofers. Subs tend to use a lot of power, car audio systems usually use 100 watt or higher amp for their subs.

Your 8" woofer is plenty to use for bass, if you want to spend money on a better setup get a 2.1 powered good speaker setup instead of adding a sub to your current setup. This will be good and same price as a decent sub on it's own https/www.amazon.com/Logitech-Z623-Speaker-System-Black/dp/B003VAHYTG

 

[americanaudiophile]

If you are happy with the sound of your present speakers except for bass I would get a self powered sub woofer with speaker level inputs. That would make connections easier since you don' t have a line level subwoofer out.
Given that you are OK with the volume you are getting with the 20 watt per channel Rotel you can go with an 8" woofer. Don't worry about how much power rating of the sub. Try an find one that has a forward firing woofer rather than a bandpass sub in which the speaker is inside the cabinet firing through a port. This gives you one note bass.
https/www.monoprice.com/product?c_id=109&cp_id=10906&cs_id=1090602&p_id=14567&seq=1&format=2