School me on amps

[awesomesteven]

I don't have any experience when it comes to audio systems so I was wondering if you guys can give me suggestions as far as what kind of amp (channels/watts) I would need.

I currently have the 4 in-boat speakers which are all 200 watts.
I also just bought a pair of tower speaker from my friend. They are 500 watts (http://www.amazon.com/dp/B0071HZJ56/..._M3T1_ST1_dp_1)

I eventually want to have a sub and add another pair of speakers along with some lights for the tower.

What kind of amp should I get (brands) that are good quality and what watts/# of channels should I be looking for?

[Sdc77]

Dépends of your budget !
Watts means nothing, a 4x30wrms Precision Power amp can destroy most of low budget speaker of 300w.

You will need for sure, 2 x 4 channel amp at least, or a 6 channel amp + 1 monochanel class D for the sub.
At least 1x 4 channel to drive in-boat front and rear speakers, 1 other to drive 2 to 4 (connected in parallel) tower speakers + 1 sub.
Becareful to focus on the power of the bridged channel of the sub amp, it as to be 4 times the single channel power. Ex : a 4x50 amp will give good result if it's a 2x200w briged system.
Depends also of your subwoofer. Is it a 4ohms single coil, or twin coil, 2x4Ohms ; 2x2Ohms ?

Marine, not marine amp, it dépends of your budget as well. I prefer cars amps as we have more choice and more quality/power/dynamic range amps.

For a boat, you can go for those band :

Rockford Fosgate ; MTX (not first prices) ; Orion ; Precision Power ; JBL (not first prices) ; JL audio (if you have a good budget ...) etc.
Forget about japaneese, german, Italian things, they will not give high pressure of sound on a boat IMO.

Hope it helps.

[Wylietunes]

I don't have any experience when it comes to audio systems so I was wondering if you guys can give me suggestions as far as what kind of amp (channels/watts) I would need.

I currently have the 4 in-boat speakers which are all 200 watts.
I also just bought a pair of tower speaker from my friend. They are 500 watts (http://www.amazon.com/dp/B0071HZJ56/..._M3T1_ST1_dp_1)

I eventually want to have a sub and add another pair of speakers along with some lights for the tower.

What kind of amp should I get (brands) that are good quality and what watts/# of channels should I be looking for?

Steven,

Your 200W in-boats are probably 200W peak. I would look for a 4 chnl class-D amp that will deliver in the range of 75-100W rms x 4 @ 4 ohm.

Or, look for a 5 chnl that will deliver about the same on the 4 full-range chnls and about 200 x 1 @ 4 ohm on the sub chnl.

Those 500W tower speakers look like a re-branded MTX tower speaker. I would look for a 2 chnl amp that will deliver about 100-125W rms x 2 @ 4 ohm, or a 4 chnl that will deliver about 150W rms x 2 @ 4 ohm bridged.

Look for amps that are Class-D as they are more efficient. This means that draw less battery amp hours to produce the same watts output of other less efficient amps.

[a_deleon]

I have 4 in boat speakers and I have 4 tower speakers all connected to a 1200w 4 channel amp. My teacher in my electronics class suggested to use a series parallel setup when wiring up the speakers and I was able to power all 8 off that 1200 watt amp having them bridged down to two channels. The tower speakers looks like you should be around 250W each if that 500W max is per speaker. I would get at least (1) 4 channel amp for the mids and highs, and either a mono block or 2 channel amp for the sub when you get to that point of adding in the sub. I am running (1) 4 channel amp for my mids and highs and (1) 2 channel amp bridge to one channel for my 15" sub.

If you want to add another two more speakers on the tower then you should look at if you plan to run one or two amps for the mids and highs then go from there. Depending on the wiring setup you do you need to make sure you have an amp that can handle the ohm rating those speakers will be running at. My series parallel wiring was able to keep me at 4ohm on each of the two channels I am using on my amp for my mids and highs. You don't want to wire it up and over load your amp so look and see what wattage and at what ohms you will be at to make sure the amp can handle it.

[awesomesteven]

Thanks for all your help guys!

[Wylietunes]

I have 4 in boat speakers and I have 4 tower speakers all connected to a 1200w 4 channel amp. My teacher in my electronics class suggested to use a series parallel setup when wiring up the speakers and I was able to power all 8 off that 1200 watt amp having them bridged down to two channels. The tower speakers looks like you should be around 250W each if that 500W max is per speaker. I would get at least (1) 4 channel amp for the mids and highs, and either a mono block or 2 channel amp for the sub when you get to that point of adding in the sub. I am running (1) 4 channel amp for my mids and highs and (1) 2 channel amp bridge to one channel for my 15" sub.

If you want to add another two more speakers on the tower then you should look at if you plan to run one or two amps for the mids and highs then go from there. Depending on the wiring setup you do you need to make sure you have an amp that can handle the ohm rating those speakers will be running at. My series parallel wiring was able to keep me at 4ohm on each of the two channels I am using on my amp for my mids and highs. You don't want to wire it up and over load your amp so look and see what wattage and at what ohms you will be at to make sure the amp can handle it.

Just an FYI, your series/parallel with 4 ohm bridged load results in each amp chnl "seeing" a 2ohm load. Same is if a pair of speakers were wired in parallel on each chnl. 4 chnls running @ 2 ohm is a lot to ask of an amp, but if tuned good, then no problems other then maybe some overheating on really hot days.

[a_deleon]

How do you get 2 ohm at the channel if in series two of them will bring it up to 8 ohm and when you put both pairs that are running in series run in parallel that would bring both sets down to 4 ohm across all the speakers. I have those 4 running at 4 ohm on one channel and the other channel is running the same for the other 4 speakers when I bridge my 4 channel down to 2 channels. I haven't had a problem over over heating it and I don't even need my gain more that half way up maybe 5/8 of the way up.

He suggested this way to wire it up to keep it where it wouldn't over heat and ask a lot from the amp. I messed up one amp because i forgot to calculate what resistance I am running and ran the speakers all in parallel so I ended up dropping it down to 1 ohm at the channels.

[Wylietunes]

When you bridge an amp, you are using 2 chnls to gain their combined output. Each chnl is seeing half of the bridged load. In your case, you are bridging a 4 ohm load comprised of four 4 ohm speakers in a series/parallel configuration. With a 4 ohm load bridged across two chnls, each chnl is seeing a 2 ohm load, thus the combined output to the 4 ohm bridged load is equal to the amp's 2 ohm x 2 output.

Here is an example:
125w rms x 4 @ 4 ohm
200w rms x 4 @ 2 ohm
400w rms x 2 @ 4 ohm bridged

See the math? with 4 2 ohm loads, one per chnl, the amps rms output is 800w rms. With two 4 ohm loads bridged, the amps output is the same 800w rms. So i am just stating that your configuration is the same net output to all 8 speakers and the amp is running at the same load per chnl as if a pair of speakers wired in parallel where wired to each chnl.

If you are running the same 8 speakers as before and ran a 4 chnl amp before and used all 4 chnls to power all 8 speakers, I do not see how you had a 1 ohm load on any chnls.

[a_deleon]

Ok I see what you're saying on it being equal to the 2 ohm load. I might need to turn down my gain on the amp to help not burn up my speakers then. My kicker speakers on the tower are 65w rms according to the Kicker 6200 manual. So if I am getting 600w @ 4 ohms bridged I only need 260w rms for those speakers to run as designed. I have it about 3/4 of the turned up so if I am looking at it correctly I am pushing more then what those speakers need when bridge down two channels down to one right? This is where i got confused when I would talk to my teacher about this. I understood that we can make the resistence go up and down and that we just add all the wattage together to see how much we need to have there to provide the power to all the speakers.

As for when I messed up my previous amp I had 4 speakers on one of the bridged channels. I had all 4ohm speakers in parallel so that would have put it down to like 1 ohm when all 4 are in parallel right?

[Wylietunes]

yes, four 4 ohm speakers wired in parallel would be a 1 ohm load. Bridging that would be placing a .5 ohm load on each chnl. Not only a rare few mono amp will handle a .5 ohm load.

Regardless of impedance load, number of speakers or speaker type, gains should never be above half way in general. Even with a low 2V head-unit, we rarely find the gains at or above half way. I would google "gain setting" and fallow one of the 3-4 good methods. They can be set by ear or with a DVOM or O-scope. I probably have one I can post here, i juts need to did it up.

Im gonna take a stab and say that you 1200W amp is 600W rms. This gives you a 300W x 2 rms @ 4 ohm. This has each speaker netting 75W rms. Thats spot on. Reset the gain, make sure the cross-over filters are set to hi-pass on all chnls and set the frequency to 120Hz for the towers and 120Hz for the in-boats if they are also 6.5" speakers.

We cant change the resistance of the speaker(s), only change how multiple speakers are wired together, thus ending up with a predetermined impedance. Theres only so many ways to wire the speakers, so we already know what impedance loads we can end up based on ohms law. Its just a matter of choosing which configuration is best for the amp.