knottysmooches

Advice and suggestions encouraged.

My new to me 2006 Formula 280 is in mint shape with the exception of the speakers. They are the original 6X9s. They crackle and are basically toast. I do enjoy a good stereo but like us all I am on a budget. Below is what I am considering all components will be Rockford Fosgate. I am going to install and make everything my self. My budget is around $2000. I am using ebay and other sites to try and buy demo speakers or slightly used.

1. Bow Area- Replace 6X9 pair with 2 pairs of 6.5" RF M262B. I need to do this because a 8" RF M282 will not fit. To make this work I am going to use an acrylic mounting plate with the back side painted white and the front frosted so the original whole can not be seen. Each mounting plate will accommodate 2 speakers. I am also going to install LEDs around the cutout for each speakers. To power the front area I am going to use a 4 channel RF amp that has 100 watts per channel this amp also has a remote volume knob that will be installed by the helm.

2. Main area- Replace each of the 6X9s (one by the helm and the other is by the back seating area) with a RF 12" sub M212. I am going to make custom acrylic speaker rings with LEDS. These two subs will be powered by the RF 1200watt 2 channel amp. This amp also has a remote volume control and will be mounted by the helm.

3. Main Area- Add 2 pairs of RF 8" M282. One pair forward by the helm. One under the starboard side aft and one under the rear bench. Each with speaker rings and LEDs. To power these I am going to use a the RF 600 watt 4 channel amp with remote volume knob

4. I want to add at least one more battery but I am not sure if I should put it in the storage area where the amps are going or in the engine compartment and run heavy gauge wire to the amps. The amps are being installed ahead of the helm in a large storage compartment.

My head unit is still in great shape and I plan on using it.

Any suggestions would be great.

kevinb230

Run the battery as close to the amps as possible and if possible close to the charging source. Reason being that a high voltage, high amperage amp supply line has a lot of loss that cannot be compensated for, and a low voltage (2.5-4V) RCA input has losses that can be made up for. (input voltage adjustment on your amps)

Longer distances in the lines between the amp and speakers are fine because the voltages are higher (i.e. long distance electrical lines)

Go with all digital amps, not the old class D amps. reason being that a digital amp is more efficient than older amps (less energy converted to heat). How do you know, because digital amps will say so, and they have significantly less cooling fins. The amp draw is less too.

If you plan on sitting for a while and running the stereo, run a separate battery (or multiple) of the stereo, on an isolator. This allows a bank of batteries to be drained down while preserving the engine battery, and both banks charge as soon as the motor is started, all without switching.

Another reason to install the amps close to the engine and batteries is that you can run a bilge fan directly to pump air over the amps.

Don't run a remote amp control on anything, have it controlled by the head unit. Most are poorly designed and add interference.

Your local welding supply store will have the best deal on supply wire, ask for a grounding wire (fine strand and heave gauge) just like you will get at the stereo shop for a fraction of the cost.

Don't forget about the power of bridging your amps!

Jonesyfxr

iTrader: (1)

With over 20 years of wiring experience I can suggest a few things....

Use a good, multi strand wire for power and ground
Use a bigger cable than necessary, such as 2 ga
Use good, soldered cable ends to prevent corrosion inside the terminal
Buy high quality RCA cables

Personally, I would replace the speakers with the same original a size. Two 6.5" coaxials with grills will require at least 14" of area and would require some cutting. If you're comfortable with that, jump right in.

Good luck and don't forget....pictures help!

knottysmooches

Thanks everybody. I cant install the amps close to the engine they need to go ahead of the helm. I will take your advice and use good wiring and place the batteries near the amps on an isolator. I will upload pictures next time I am on the boat. Thanks for the heads up on the remote amp controls. I will pass on them and use the head unit. I am okay with cutting to accommodate the two 6.5s.

I will look into these amps and see if they are digital.

Once again thanks guys.

liquidlounge

iTrader: (1)

I thought the class D amps amps are the more efficient amps? Not debating, just wanting clarification as I'm getting ready to upgrade my system.

Pliant

•A car audio amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Whoa, yeah that may be hard to swallow for some people. To put it in every day terms, an amplifier takes an electric signal and makes it bigger which translates into louder and better sounding music for us. Thank you engineers! Amplifiers use many different methods for converting these electrical signals and as you research amplifiers you will often see “Class A/B” or “Class D” and sometimes other classes all together. What does the class letter mean and which one is right for you? Let’s find out!

Class A
The input signal is used 100% of the time in class A amplifiers. What this means is that the output signal (to your speakers) is an exact amplified replica of the input signal (from your headunit) with almost no clipping or distortion. However, these amplifiers run extremely hot because the transistors in the amp are on all the time. These amplifiers have a very simple circuit design compared to the other classes and have the least distortion. In a nutshell, for the price of running hot, you get great sound quality. These types of amplifiers are used in low-power applications such as to drive headphones. You will most likely not find car audio Class A amplifiers because 1000 watts of heat could be generated just to get a few hundred watts of audio. Not a great compromise.

Class B
In most Class B amplifiers, there are two output devices, each of which conducts alternately (meaning in a push-pull fashion). 50% of the input signal is used so they only amplify half of the wave cycle. What this means is that class B amplifiers tend to create a lot of distortion but they are far more efficient than class A amplifiers. The positive and negative halves of the input signal are dealt with by different parts of the circuit and then the output continuously switches. Still, you may never see a class B amplifier in the audio world. These amplifiers are favored in battery-operated devices, such as transistor radios.

Class A/B
These amplifiers are the most commonly used amps of today in car audio. They combine the best of both worlds with class B efficiency and the great sound quality of class A with low distortion. Class A/B amplifiers run very similar to class B in that half of the signal is amplified and the other half is “off”, however the deadzone has been reduced. This means that a bit more of the signal is being amplified, greater than 50%, so the instance where both would be “off” has been reduced. Class A/B is a good compromise for audio amplifiers, since the average listening volume is relatively low, keeping the amplifier in A range in terms of sound quality. When you crank the volume up the distortion levels are less than class B.

Class D
The main benefit of Class D amplifiers is the efficiency, often times at or over 90% is attainable. This efficiency is extremely high compared to class A/B amps which run less than 78% efficient. This translates into smaller heatsinks, less power draw from your vehicles charging system, and smaller internal components. These amplifiers switch their output devices “on” and “off” instead of an always “on” which creates a square wave as opposed to an analog sine wave. This square wave contains inaccurate pulse frequency and harmonics which must be removed from the signal which is done by a technique called PWM (Pulse Width Modulation). Cleaning up the signal of a class D amplifier is relatively difficult so they are best used in applications where quality is not a factor, such as driving subwoofers. Class D amplifiers have inherently low output impedance, usually down to a 1 ohm load, which makes them ideal for running subwoofers. High quality class D amplifiers are starting to appear and some even rival class A/B amplifiers in terms of quality. Do not mistake a class D amplifier as being “Digital”; this is not usually the case. Class D is simply next in the list after C. Digital class D amplifiers are controlled by digital circuits which convert the signal into zeros and ones and then digitally process the signal to remove errors. Class D amplifiers appear to be the way of the future.

Other Amplifier Classes
Some manufactures have started producing amplifiers with class names such as bD, GH, etc. These class names do not reflect any breakthrough in technology, but rather reflect tweaks to improve on the current class A/B and D designs. For example, class GH amplifiers deliver the efficiency of a class D amp with the sound quality of an AB design. It does this because it is not a switching amplifier (on and off) and employs different “rail” voltages with a special control circuit that switches back and forth between the rails as the signal fluctuates. This reduces the amount of wasted output power; however these amplifiers are sophisticated and costly to produce. As for Class bD amplifiers they have an efficiency rating closer to that of class D amplifier (75-80%) vs. the tradition ratings of class A/B amplifiers (20-60%). These amps are more complex than the tradition class A/B and filtering problems are simplified. As time goes by you will see more amplifier classes appear that offer improvements over the general class A/B and class D designs.

Conclusion
So if the above mentioned information is giving you a headache let’s just get down to the basics. Which one is right for you? The most common amplifiers in the car audio world are class A/B and class D. You will find most speakers are run using class A/B amplifiers and subwoofers are driven by class D amplifiers. It is difficult not to stick to that pattern of play as you will find few deviations of it. Soon we will start seeing all class D systems, until then let A/B hold its rein.

Buy Car Amp

kevinb230

You are right, in relationship to being all analog amps. Newer amps have the same class ratings, the digital aspect of these amps give it better efficiency and sound. You will still get a class D or class AB, it will just be digital

sleev-les

You guys are really making it hard for me to get through the rest of this winter. I'm doing my stereo this summer, along with some lighting and a GPS speedo upgrade (have the old water pickup style now). I guess I can go look at what Im going to buy as far as amps/speakers/subs lol...

OP, good luck with the install. I love having a kickazz system.

knottysmooches

Thank you for the information. Something I don't really understand but have researched is bridging speakers. My question is based around the JL Audio M1000. It has 4 channels for speakers and one channel that is for driving two subs. Obviously this will give less power then 3 amps but will it be enough? I was thinking I could hook a pair of speakers to a single channel. I am not sure what this does for sound quality or volume.

kevinb230

I have experience with this amp in the non marine side, it is a solid amp but lacks for long term loud play (highs cut out after a few min). Your sub output is also going to suffer.

A better bet would be to get a 6 channel amp for your speakers. Look at the M600/6 by jl audio
For the subs get a jl audio M600/1 and wire your two subs in Parallel giving you 600w RMS at 2ohm.

This is a very safe system that will last any abuse that you throw at it. Larger amps will provide you with prolonged high output, but you run the risk of blowing a speaker