3 channel amp with woofer output ?

[ZipSnipe]

I am getting ready to buy a 3 channel amp with woofer output. Will I still need a crossover?

The amp is 2x50 watts x100 watt sub and I plan on putting 3 @ 5watts speakers on each channel and a 50 watt sub all speakers are 8 ohm so the amp will be putting out half . So will I be alright with the speaker load? I always heard it was better to have more amp

 

[zimmer64]

There are too many unknowns in your question. I guess you have to let us know, what amp you are buying and what the speakers are.

 

[ZipSnipe]

Thanx for the reply. This is for a bluetooth column speaker build that I am doing here is a diagram with specs. I believe if I wire the 3 @20 ohm speakers parallel that I should end up with 5 ohms, correct me if I am wrong

 

[ZipSnipe]

This is the amp I bought

Digital 2.1 Channel Amplifier Board Bluetooth USB Input 50W+50W Stereo 100W im | eBay

 

[giralfino]

You need a crossover, a high pass for the sub and a high pass for the satellites (*). This amp is basically simply 2 amps into one package: one amp for a stereo output and one amp bridged for a mono output.
As far as load, 3x 20 Ohm drivers connected in parallel are equivalent to a single 20/3= 6.7 Ohm load (forgetting about the fact that a driver is not a pure resistive load, and also that I've never seen a 20 Ohm driver).

Ralf

(*) If you plan to run the 3 drivers in parallel without any low pass filter, be aware that this is not a good idea because of comb filtering when the inter distance between the drivers is more that the wave length involved.

 

[MartyMG]

Hi, here's an interesting new plate amp version with adjustable low pass and presumably high pass for the satellites
Bluetooth 4.2 Digital 2.1 Channel Subwoofer Integrated Amplifier Speakers Board

 

[ZipSnipe]

You need a crossover, a high pass for the sub and a high pass for the satellites (*). This amp is basically simply 2 amps into one package: one amp for a stereo output and one amp bridged for a mono output.
As far as load, 3x 20 Ohm drivers connected in parallel are equivalent to a single 20/3= 6.7 Ohm load (forgetting about the fact that a driver is not a pure resistive load, and also that I've never seen a 20 Ohm driver).

Ralf

(*) If you plan to run the 3 drivers in parallel without any low pass filter, be aware that this is not a good idea because of comb filtering when the inter distance between the drivers is more that the wave length involved.

Thanx for the reply, so it sounds like I need three crossovers one for each channel.

Yeah I never heard of 20 ohm speakers either but I have seen. 40 and 60 ohm speakers

 

[Pano]

I have several amp boards similar to this one, tho not this exact model. Most have a low pass filter built in for the sub. You will know if this one does just by listening to it.

The main problem with the various boards is that although the amps are fine, the Bluetooth is super noisy. I hope yours is better.

 

[ZipSnipe]

Thanx I will let ya know if the bluetooth is noisey as this will be the main way I plan to use it. The build quality looked good on this board which is why I went with it

 

[Pano]

Please let us know. Always on the lookout for boards like this of good quality.