Calling stereo guys!

[Nosnibor]

So...I racked up some more debt and bought some new speakers for the boat. My boat has the Jensen system stock. My hope is that I can simply unplug my old speakers and put my new ones in. The thing I don't understand completely is all the power stuff like RMS and Peak wattage.

Will my head unit be able to put out enough for the newer speakers?

If it doesn't it shouldn't do any damage but not play as loud?

Should the stock wiring be ok?

I'll leave it there for now. Thanks for the help!

 

[jimmaki]

Generally speaking you should be fine if they are just upgrade or different brand speakers for boat head units. If the new speakers are much lower impedance (ohms) than the new ones, they could possibly damage your head unit amplifier output transistors unless they are rated for the lower impedance (higher current). Many amps are rated across a range of impedances, usually from 4 ohms to 16 ohms. Example might be 100 watts into 8 ohms and 200 watts into 4 ohms.

If the new speakers are a higher impedance than the old ones they may not play as loud but I wouldn't expect them to do any damage to the amp unless you wire them up differently such as in parallel.

If your stock wiring is 12 to 14 gauge it should be fine as long as you don't have some megawatt system and aren't running very long wire runs. Some audiophiles like monster cables in the 8 to 10 gauge range but a boat isn't exactly a studio listening experience.

 

[Nosnibor]

Generally speaking you should be fine if they are just upgrade or different brand speakers for boat head units. If the new speakers are much lower impedance (ohms) than the new ones, they could possibly damage your head unit amplifier output transistors unless they are rated for the lower impedance (higher current). Many amps are rated across a range of impedances, usually from 4 ohms to 16 ohms. Example might be 100 watts into 8 ohms and 200 watts into 4 ohms.

If the new speakers are a higher impedance than the old ones they may not play as loud but I wouldn't expect them to do any damage to the amp unless you wire them up differently such as in parallel.

If your stock wiring is 12 to 14 gauge it should be fine as long as you don't have some megawatt system and aren't running very long wire runs. Some audiophiles like monster cables in the 8 to 10 gauge range but a boat isn't exactly a studio listening experience.

Thanks for reply. I'm not sure about the ohms/impedance of the old speakers. So if the new speakers are lower than what the head is rated for it could cause damage but most heads are rated for a broad range? That's what I think I got from that.

 

[jimmaki]

Yes, that's about it. Most Jensen boat speakers are 8 ohm. Your new ones should be marked. If you turn up the volume on new speakers and hear a lot of distortion it generally means your amp is clipping which is a sign it is underpowered for those speakers. Continual loud distorted use will result in damage to your amp, speakers and maybe your hearing.

 

[Nosnibor]

Yes, that's about it. Most Jensen boat speakers are 8 ohm. Your new ones should be marked. If you turn up the volume on new speakers and hear a lot of distortion it generally means your amp is clipping which is a sign it is underpowered for those speakers. Continual loud distorted use will result in damage to your amp, speakers and maybe your hearing.

So I just looked up and the new speakers are 4 ohm. So I may want to look at getting a new deck in the future? Also when does need a separate amp unit itself become a thing?

 

[Nosnibor]

Okay, so I went out and got the model # and found the specs online. Speaker Impedance is 4-8 ohms per channel. So I think I should be good for ohms. The power output is 40w x 4. First, does each speaker count as a channel? And does that mean the max per channel is 40 watts and if my speakers are 100 watts rms I am missing 60 watts of sound? lol...

 

[tkarvelis]

I will bet you will need an amp. 160 total watts sounds like a lot, and it is in a car, but on a boat you are not in an enclosed space, and you have an engine up close and personal.

I thought I would be good on our boat last year when I put a new radio and speakers, but I needed an amp too.

 

[Nosnibor]

I will bet you will need an amp. 160 total watts sounds like a lot, and it is in a car, but on a boat you are not in an enclosed space, and you have an engine up close and personal.

I thought I would be good on our boat last year when I put a new radio and speakers, but I needed an amp too.

I'm slowly starting to piece it all together. Since the deck is 40w x 4 and the speakers can handle 100 I would need an amp connected to the deck and the speakers to make my extra 60 watt? So I would be looking for an amp that has 100w x 4? Also if I wanted to have a sub in the future would I need more than the 4 channels?

 

[Nosnibor]

If for the time being I just have the new speakers in and they never go above 40 watts will that hurt the speakers? I just won't get all the juice from them right?

 

[tkarvelis]

No you will not hurt the speakers. You can hurt the amp in the radio if you crank it to full volume for a long time. The amps today are not clean at full volume and have a lot of distortion.

Sent from my SM-N910V using Tapatalk

 

[Nosnibor]

No you will not hurt the speakers. You can hurt the amp in the radio if you crank it to full volume for a long time. The amps today are not clean at full volume and have a lot of distortion.

Sent from my SM-N910V using Tapatalk

But that is just because the stock head amps are crap right? So going forward I need to be looking for a new head and amp. When looking at RMS power does the head and amp combine or does the amp take it all?

 

[tkarvelis]

No your stock head unit should be fine if it does what you want it to do. The amp will take the audio speaker power and use it to drive the amplifier. And boost the power and make it louder with less distortion

Sent from my SM-N910V using Tapatalk

 

[jimmaki]

But that is just because the stock head amps are crap right? So going forward I need to be looking for a new head and amp. When looking at RMS power does the head and amp combine or does the amp take it all?

How does it sound? Is it loud enough? When it's at the volume that you are comfortable with do you hear any distortion? Forget about "losing watts" or matching amp watts to speaker watts. 20 watts of clean undistorted sound x 4 at the speakers in an area the size of a boat should be loud enough for most people. A 400 watt amplifier if I is rated at 100 watts per channel into 4 ohms with less than 1% harmonic distortion would be a great match for your speakers, but you would probably not use it over 1/4 volume before it was uncomfortably loud (unless you are deaf from attending too many rock concerts) and will annoy people in other boats and along the shore. So then, you are wasting money by buying into the watt myth when what you should be concerned with is it loud enough for you without distortion?

Look at it this way, if your boat hull is rated for 600 HP and you only have a 250 HP engine in it and it goes 60MPH, are you wasting 350 HP? If a 600HP engine will push your boat at 100 MPH making it uncomfortable and scary to ride in, would you spend the money on a bigger engine if you normally cruise around at 40MPH and only occasionally go 60?

 

[Nosnibor]

How does it sound? Is it loud enough? When it's at the volume that you are comfortable with do you hear any distortion? Forget about "losing watts" or matching amp watts to speaker watts. 20 watts of clean undistorted sound x 4 at the speakers in an area the size of a boat should be loud enough for most people. A 400 watt amplifier if I is rated at 100 watts per channel into 4 ohms with less than 1% harmonic distortion would be a great match for your speakers, but you would probably not use it over 1/4 volume before it was uncomfortably loud (unless you are deaf from attending too many rock concerts) and will annoy people in other boats and along the shore. So then, you are wasting money by buying into the watt myth when what you should be concerned with is it loud enough for you without distortion?

Look at it this way, if your boat hull is rated for 600 HP and you only have a 250 HP engine in it and it goes 60MPH, are you wasting 350 HP? If a 600HP engine will push your boat at 100 MPH making it uncomfortable and scary to ride in, would you spend the money on a bigger engine if you normally cruise around at 40MPH and only occasionally go 60?

That's a good explanation and I didn't think of it like that. Now I am wondering if it was the unit that was causing my distortion in the speakers. The new speakers will go in now since I bought them already but I will mess around with volume and if it stills gets distorted then I will look for an amp. I really never knew that distortion could come from the power source being crappy.

 

[Nosnibor]

No your stock head unit should be fine if it does what you want it to do. The amp will take the audio speaker power and use it to drive the amplifier. And boost the power and make it louder with less distortion

Sent from my SM-N910V using Tapatalk

So if I get an amp I can run the power from the deck to the amp without running a thick gauge wire from the battery to it?

 

[jimmaki]

That's a good explanation and I didn't think of it like that. Now I am wondering if it was the unit that was causing my distortion in the speakers. The new speakers will go in now since I bought them already but I will mess around with volume and if it stills gets distorted then I will look for an amp. I really never knew that distortion could come from the power source being crappy.

Well, it can be caused by either (or both). Even with high powered, clean amps, some speakers can distort. I won't get into the technical reasons why, but realize there are 8" 4ohm 100 watt speakers that sell for $5 and 8" 4 ohm 100 watt speakers that make up sound systems that sell for over $500.

Before you go even more in debt, consider some realities of physics:

Big powerful sound systems with subwoofers use a lot of power. Not a problem for a home system on 115 volts or a car with a 100amp alternator. But for boats, especially SeaDoo boats with small 12 volt batteries, limited current voltage regulators, and under voltage/over voltage sensitive mpems, appreciate the following.

The formula for instantaneous power is P=I*V where P is power in watts, I is current in amps and V is voltage in volts. The reason I bring up this techno mumbo jumbo is to illustrate as simply as possible why 12 volt high powered sound systems in boats are impractical. To develop full power output with a 400 watt amplifier, it would take 33.3 amps (using the above formula 400 divided by 12), and that is at 100% efficiency which most amps are not. So you could be drawing 33 to 60 amps from your battery which will mean you will need at least another battery, a battery switch to isolate your starting battery so you can get home, and a box full of spare voltage regulators and possibly mpems. My 200HP Mercury has the optional 40amp double voltage regulator setup and it still blows regulators if I run the battery down with a 120 watt stereo, tube inflator, small cooler and running lights which all told don't come to 200 watts. Now consider most SeaDoo engines have 15 amp fuses to protect the charging system. The actual maximum charge rate would be some safe level less than that fuse rating.

 

[Nosnibor]

Well, it can be caused by either (or both). Even with high powered, clean amps, some speakers can distort. I won't get into the technical reasons why, but realize there are 8" 4ohm 100 watt speakers that sell for $5 and 8" 4 ohm 100 watt speakers that make up sound systems that sell for over $500.

Before you go even more in debt, consider some realities of physics:

Big powerful sound systems with subwoofers use a lot of power. Not a problem for a home system on 115 volts or a car with a 100amp alternator. But for boats, especially SeaDoo boats with small 12 volt batteries, limited current voltage regulators, and under voltage/over voltage sensitive mpems, appreciate the following.

The formula for instantaneous power is P=I*V where P is power in watts, I is current in amps and V is voltage in volts. The reason I bring up this techno mumbo jumbo is to illustrate as simply as possible why 12 volt high powered sound systems in boats are impractical. To develop full power output with a 400 watt amplifier, it would take 33.3 amps (using the above formula 400 divided by 12), and that is at 100% efficiency which most amps are not. So you could be drawing 33 to 60 amps from your battery which will mean you will need at least another battery, a battery switch to isolate your starting battery so you can get home, and a box full of spare voltage regulators and possibly mpems. My 200HP Mercury has the optional 40amp double voltage regulator setup and it still blows regulators if I run the battery down with a 120 watt stereo, tube inflator, small cooler and running lights which all told don't come to 200 watts.

A lot more good info. Thanks. I guess I thought it was just easier because I see a lot of people with big sound systems on their boats playing music for the whole beach to hear. I don't necessarily want that. I would just like to have good cruising speed sound. Right now when the system is turned up while driving it is really distorted. So I will try with the new speakers and see how that sounds. I guess if it is still distorted it would be the deck and I would be looking at a new one or an amp?

I typically don't run the stereo too long while the boat is off and would consider a 2nd battery if I were to do that for a longer period of time.

In the future I would love to have a sub which I know I will need an amp but I guess I will just take it to a shop. I was hoping to try to DIY.

 

[jimmaki]

A lot more good info. Thanks. I guess I thought it was just easier because I see a lot of people with big sound systems on their boats playing music for the whole beach to hear. I don't necessarily want that. I would just like to have good cruising speed sound. Right now when the system is turned up while driving it is really distorted. So I will try with the new speakers and see how that sounds. I guess if it is still distorted it would be the deck and I would be looking at a new one or an amp?

I typically don't run the stereo too long while the boat is off and would consider a 2nd battery if I were to do that for a longer period of time.

In the future I would love to have a sub which I know I will need an amp but I guess I will just take it to a shop. I was hoping to try to DIY.

Sounds like a good plan. Some amps have a separate subwoofer out and can combine the L/R signal to a mono signal for the subwoofer. If your head has RCA outs you can run those to most any amp. But don't run the head speaker outs to the same speakers the amp will be connected to. Disconnect the head speaker wires.

A sub woofer is a simple DIY project, you just need an amp with a subwoofer output, or a separate subwoofer amp and signal splitter or a subwoofer with a built-in amp. No big deal to wire up.

Subwoofers have to move a lot of air to sound good. Takes a lot of power (and money). My home subwoofer amp is 400 watts for just the one 18" speaker.

Keep in mind most SeaDoo charging systems are laughingly "protected" with 15 amp fuses so even under way, you're pretty limited as to how much power you can consume without running the danger of a battery deficit, blown fuses or worse blown electronic components and even worse getting stranded. Some of the boats playing loud enough for the whole beach to hear probably run inboard or I/O automobile engines with hefty altenators.

How about some good waterproof headphones?