Stereos & Batteries - Read before buying.

[thaphillips]

If your considering putting a new stereo system in your boat please read this thread before you start buying and installing. I am a car audio guy, and others can probably offer more marine specific advise. So you experts feel free to chime in when necessary.

I have seen lots of guys on the water with loud stereo systems but that have lots of batteries or can't play there audio loud for extended periods of time. As Checkmates are about keeping a good horse power to weight ratio so adding lots of batteries would really hurt your performance.

The ideal situation would be to power your speakers off your head unit. Many of us need more power as we want to run louder speakers or subs. In these cases an amp is necessary for more power. Many amps will drain the battery pretty in a short amount of time. The ideal setup would be to have one cranking battery for the engine and one deep cycle battery for the stereo. A cranking battery is designed to provide more power to start your engine, but is not designed to be run low and recharged regularly. Mean while the deep cycle battery is not good for starting the engine, but is designed to be ran low and recharged regularly. If you decide to run a two battery set up run an isolator switch between the batteries or you might end up with two dead batteries.

With careful amp selection you could run a nice sounding system with out the need for a second battery. When selecting an amp pay careful attention to the class of the amplifier. Class A, B, and A/B amplifiers are the least efficient and will drain your battery in no time. Class D amplifiers are about 30% to 50% more efficient. Many people will tell you Class D amplifies are only good for subs due to distortion on higher frequencies. These people are simply ill informed. Advances in design allow Class D amplifiers that will work well with both subs, mids, and tweeters. When selecting remember the more watts your amp draws the more it drains the battery. So look for an amp where the maximum wattage is about as loud as you would play your stereo. If you get a 2,000 watt amp and only listen to your stereo at 500 watts your only draining your battery. Also try to get one amp that will run all of your speakers. Multiple amps mean more battery drain. There are a couple 4 Channel Class D AMPS, that should be able to run 4 speakers and a sub, yet only cost around $200.

I would suggest something like the Cerwin-Vega SX440.4
http://www.sonicelectronix.com/item_22128_Cerwin-Vega-SX440.4-Stealth-440.4.html

Here is a pro audio review on the Cerwin-Vega
http://caraudiomag.com/articles/cerwin-vega-sx4404-compact-amp-test

Of course there are other brands available. I simply posted a link because some people don't like to research and just want an answer on what to buy.

...... Part 2 - Amp Features ... will follow

 

[thaphillips]

PART 2 - AMP FEATURES

If you are running your system off one Class D AMP, it is important your amp has the right features. The Cerwin-Vega I linked above has all these features.

BUILT IN ADJUSTABLE CROSS OVER or "ADJUSTABLE FILTER" - If you are running your speakers and subs off the same amp you will want this feature. It will keep bass from playing out of your tweeters and mids, and keep high notes out of your subs. Many have a "high pass" and "low pass" filter. That filter might even be selectable. Unless the cross over or "filter" is adjustable(not selectable) you can not tune the notes that go to your highs and the notes that go to your lows. If your "filter" or "cross over" is not adjustable you must pay close attention to the frequencies of your speakers, and compare them to the point at which your "filter" will cross over to the other speakers or subs. Many systems sound bad because the "filter" crosses over at a note or frequency that is not ideal for your speakers. An adjustable filter or crossover will allow you to fine tune this correcting any problems.

ADJUSTABLE INPUT GAINS - If your subs are putting out to much or too little power this will allow you to fine tune their volume.

OHM RATING - The lower the ohm rating on your amp the better. A good amp should be rated for 2 ohms or less. A simple formula is every time you cut your ohms in half your watts will double. Ohms is a measure of resistance and the easier the power flows, the higher the speaker goes. An amp rated for two ohms should be able to play 4 speakers off two channels. Using the Cerwin Vega SX440.4 as an example you could put a sub on Channel 1&2 and 4 speakers( 4 ohm) on channels 3&4. A general rule of thumb is that your speakers should never be rated at a lower ohm than your AMP. Or if your buying a 2 ohm stable amp then you should buy 4 ohm speakers.

MARINE vs Non-Marine Amp - That is case specific. Do you run mostly in fresh water? Is you amp mounted in an area where it will stay dry? Do you store your boat in covered storage? If you answered yes to all these questions, you probably do not need a marine specific amp. I understand if you prefer to buy one for piece of mind, but the selection of quality marine amps is minimal. It tends to either be expensive or junk with no middle ground. Just for reference the Cerwin-Vega amp is not a marine amp.

 

[thaphillips]

PART 3 - HEAD UNITS OR "STEREOS" and USELESS FEATURES

I personally find that I try to avoid listening to CD's on the lake due to skipping and the hassle of changing discs. Several of my friend have lost expensive ipods to the lake. I suggest using a head unit or stereo that allows you to use USB storage devices or better yet SD cards. You can store a lot of songs on these devices and you simply plug them in and forget them. SD is really my preference over USB because the USB storage protrudes while SD mounts flush. This is important because I like to close the splash guard on my radio.

MARINE vs CAR STEREO - Depends on your application. If you pay attention to what your doing (ie .... you dry your hands before touching the stereo), run in freshwater, and keep your boat in covered storage .... then a car radio will usually work out okay.

HIGH POWER (WATTS) STEREO - If your running an amp it's pointless to get the high watt stereo, as the AMP is the one pushing the speakers not the head unit. A high watt stereo will only drain your battery faster. Instead look for a lower watt unit. Truth is the sound quality is going to be primaily based on your AMP not your head unit. I guess to sum it up, you can get buy with a cheap head unit. Save your money for the AMP and speakers. ALSO MAKE SURE THE STEREO HAS RCA OUTS as this will allow you to easily hook up your amp. If you stereo does not have RCA outs there is a possibility that you are unable to hook up your amp.

CD PLAYER - the fewer moving parts on your radio the better. I suggest looking for a "Mech Less" radio. These have no moving parts. Which means less to break.

CLOCK - Most people disconnect their battery when storing their boat Do you really want to set the clock every time you take the boat out?

STATION PRESETS - See "Clock" above then substitute the word clock for presets.

REMOVEABLE FACE - The monster of the lake likes to eat ipods and stereo face plates.

REMOTE CONTROL - How lazy are you? How good is your song collection. I could understand why some people want a remote control. Truth is the monster of the lake likes remotes controls as a mid day snack. Simple solution .... only put songs you really like on your SD or USB storage device.


So for those of you who want a link to a Car Stereo I would suggest for your boat here it is ....

Dual XR4110 (can be found for about $35 on amazon)
http://www.sonicelectronix.com/item_20179_Dual-XR4110.html


COMING SOON ..... PART 4 - SPEAKERS ..... make it or break it

 

[thaphillips]

PART 4 SPEAKERS .... make it or break it .....

Most people are going to run two different kinds of speakers one for the Highs and one for the Lows.

MARINE vs CAR AUDIO - This is an area where I would consider getting Marine grade over car audio, due to the location of the speakers. However if you find the correct car audio speakers they will last almost as long as marine grade speakers. If your buying car audio speakers avoid speakers with paper cones. Instead focus on speakers that have plastic cones and tweeters and have a rubber surround. Most speakers will list the materials used in the product description. Don't be lazy ..... preform an internet search if you are not familiar with the materials used and make sure they are water and uv resistant. There are two many materials used for me to list them all.

SIZE - The most common size speakers used for your high notes are going to be 6" or 6"x9" or 5.25" depending on the room available. Look at the RMS rating for watts as this is the true watts not the made up number.I suggest putting your speakers in an enclosure (box) for best results. Also look for two way speakers as they will sound better. I find three way speakers to be of minimal use if you are running subs. Generally the larger speakers preform better, so get the largest size available based on mounting location.

NAME BRAND - In general most no name speakers sound like garbage. The speakers are the most important part of your system. JL Audio and Polk Audio make some nice sounding marine speakers. Kicker makes some good sounding car audio speakers that will hold up well in a marine environment. Kenwood, JBL, and Clarion are in the middle of the pack. There are others available, but I tried to list the common brands. If you bought one item at the shop and not online, I would suggest it be your speakers. Listen to them before you buy. You should make sure your speakers are 4ohm speakers as they are the most versatile.

Here are some links

Kicker KS600
http://www.sonicelectronix.com/item_11501_Kicker-KS600.html

Polk Audio DB651
http://www.sonicelectronix.com/item_9111_Polk-Audio-db651.html

JL Audio MX650
http://www.sonicelectronix.com/item...650-CCX-CG-WH-White-with-Classic-Grilles.html

With JL Audio the MX line is good, Polk Audio the DB line, and Kicker the KS line.These are all the mid range performance speakers from their manufacturer.

SUB WOOFERS -The 2ohm subs are better constructed, offer less resistance, and more performance. If you get a 2ohm sub, you must make sure your amp is rated for 2 ohms. If you run a 2ohm sub bridged then your amp must be rated for 1ohm. However, the safest best is to get a 4ohm sub. Most of us will only run one sub to try and minimize the weight/space penality. If you only use one sub, your can bridge it and use two channels to run your 4ohm sub at 2ohms, thus doubling your wattage. Remember your subs put the most strain on your battery and you have enough power with out bridging your sub then you shouldn't bridge it. Last note .... a shallow mount sub means you can use a smaller enclosure. If you get a car audio sub, be sure to research the materials used in the product. You should not have to spend alot of money to get a decent sounding sub. Remember a great sub will sound bad if you have a bad enclosure and poor quality amp. Save some money on the sub and use it on your amp or enclosure. A good sub can be had for $50 - $75.



Here are some links for reasonable 8-inch 4ohm car audio subs. Remember to search the web for the lowest price.

JL AUDIO 8W
http://www.sonicelectronix.com/item_15351_JL-Audio-8W1v2-4.html

Kicker 10C84
http://www.amazon.com/s/ref=nb_sb_noss?url=me=A3MJ987JELUZUB&field-keywords=KICKER+10C84&x=0&y=0

JBL GT0
http://www.sonicelectronix.com/item_7443_JBL-GTO804.html



SUB ENCLOSURES - The sub enclosure is vital to the performance of your sub. The most important part of the enclosure is the mounting dept of the box. So the distance from the mounting point to the back of the box. For an 8" sub you are going to need about a 12" mounting dept for best performance. There are two main types of enclosures ... sealed and ported. I suggest sealed because you can use a slightly smaller enclosure. A ported enclosure needs to be tuned to your sub. I do not recommend them, unless you are an audio phile, as there is a larger margin for error. Try to avoid the boxes that are tall and shallow as they do not preform as well. The best preforming enclosures in general tend to be square shaped for one sub applications. Don't cheap out on the box, get a good box.

Atrend makes nice 8" boxes.
http://www.amazon.com/Atrend-Single...?s=electronics&ie=UTF8&qid=1300945042&sr=1-18

I hope you enjoyed this post. I may add more information in the future, but it's time for me to sleep now, so please turn down your system!

 

[keith4216]

I applaud your time and interest in this post, but I feel this is like building a custom motor. Every application is different. I'm feeling your coming from the point of veiw of a small exposed stereo boater. My self having a larger boat and most eguipment not exposed ,I could argue a lot of your points.
Just as a point to start,
REMOTE CONTROL - How lazy are you?
This statement doesn't applie to me, My stereo is in the cabin and I need a remote to work my stereo without climbing in and out of the cabin. My remote is wireless and mounted. No river monsters getting it!

I'm just saying I like what your getting at, but remember to keep it general enough to applie to most of us and for the man who knows nothing about stereos to be able to understand. Stereos can be very detailed or very simple, theres no one way.

 

[DropTop5.0]

Great post. It might be over some heads and under others but I enjoyed reading it. Thanks.

 

[illMATTic]

Good post. This should get some people started in the right direction.

 

[thaphillips]

Looking back I think I was hurried in the part about subs. We need some elaboration on single vs. dual voice coils. Also it's important to match your amp watts to the recommended watts on your sub.

 

[rhino1653]

I agree with Keith. Alot of good info, but some misleading and some just plain wrong. I applaud you taking the time and effort to give people somewhere to start, but this is definitely not to be as the bible. A few discrepancies of note (I won't pick your time and effort apart, just a few things I thought needed discussed)

1. Class A/B amps are used for mid and high frequencies where SQ is concerned because the are designed to reproduce more of the input Sin Wave for use on the output side than a D class amp. D class amps are more efficient simply because it take less power, less heat dispersal, etc. to produce 30-40 of a signal. A quality A/B will amplify/produce 85-95% of the input signal, as opposed to >60 on your top of the line D class. Some people might not notice, but I can tell you first hand, It's night and day if you know what you're listening for.

2. Unless you're running a stereo in a Jet Ski, a 4 channel won't meet most peoples needs for an entire system. You would have to bridge a 3-4 channel for sub output and run a 1-2 channel in stereo on highs. Unless a person is planning on running a single pair of speakers for highs/mids and a single sub, 4 channel really doesnt make sense. The Vega amp you posted for example would provide 65W to a pair of highs, and something like 120-130 to a single sub. Might as well just turn up your iphone. Several companies do, however, offer 5 channel amps with a dedicated sub channel. Separate power supplies and input/output. While a much more expensive option than most would be looking for, Memphis makes the Memphis Belle, which is a hybrid combining an A/B 4 channel that can efficiently supply 100W to four mid/highs and a D class that is 1 ohm stable capable of powering 2-3 subs if one so chooses. It can be found online for 400ish.

http://www.sonicelectronix.com/item_4033_Memphis-Belle-16-MCH1300.html

Other more cost effective options---

Kicker

http://www.sonicelectronix.com/item...oogle&utm_medium=organic&utm_campaign=froogle

Boston Acoustics

http://www.sonicelectronix.com/item_19568_Boston-Acoustics-GT-5750.html

MTX

http://www.sonicelectronix.com/item_33847_MTX-RFL805.html

2. Having more power than you listen to will drain the battery faster. Wrong. The bigger/nicer the amp you buy, the higher impedance you can configure it to run in, thereby exponentially increasing sound quality, eliminating power issues, and increasing efficiency. An amp that can produce 75WX4 at 4 ohms stereo will run better, quieter, cooler and longer than one that produces 75 X4 at 2 ohms mono.

3. Sound quality is more about the amp than the head unit. Wrong. You can have the nicest amp in the world playing through $10,000 worth of speakers with a sh*tty input signal, and you will hear a sh*tty output signal. Don't, I repeat don't skimp on source unit to fund nicer amps and speakers. You will end up with a sh*tty sound.

4. The Dual CD player. Quite possibly the biggest turd you can buy. While I understand it will fulfill a select fews needs, and there might be several people here with it or something like it, I haven't, nor will I ever suggest people that I know or attempt to help buy a $35 CD player and attempt to use it in a marine environment. I hate the saying "You get what you pay for" but sometimes its the truth. Buy a $200 head unit once, or replace the Dual head unit semi-annually and spend it eventually. Also, that head has one set of 2V pre-outs, so you wouldn't even have the necessary connections to run a single 4 channel, let alone 2 amps, unless you started splitting the wires, thereby creating an even crappier signal than it came from the factory with. While not dirt cheap, I suggest Kenwoods Marine head unit line. I have the KMR-700U. No CD player, just a fold down face with a pocket to place an ipod/usb media device. You can plug an external hard drive and go. It has every feature you could want/need, and with no CD skipping, which I agree plagues boat stereos.

A bit cheaper, you can buy the KMR-440U. It has everything you need, Ipod control, remote ready, bluetooth and XM if you're feeling froggy, and has 3 sets of 2.5V pre-outs (front, rear, and sub). This could run the amps you suggested above.

5. Suggest putting speakers in boxes. While I don't disagree completely, it's just not feasible to do in most setups. Most Marine subs are designed as free-air woofers, so an enclosure isn't necessary. For the mids and highs, most will surface mount them in a panel somewhere, and the sound reproduction will suffer very little.

6. Three-way speakers unnecessary with sub. I'm just lost on that one. It literally makes no sense. A two-way 6X9 for example has a woofer and some form or high frequency reproduction, be it dome, piezo, electrostatic, horn, etc. A three way adds a mid spectrum frequency monitor. Something to cover the frequency between the woofer and the tweeter. I don't see what the addition of mids has to do with subwoofers in any case. If I'm misunderstanding, please let me know.

7. 2 ohm Subwoofers are better constructed and offer more performance. Couldn't be more wrong. First things first, a voice coil doesn't have resistance, it has impedance. Impedance of a subwoofer has absolutely nothing to do with construction. You can order a Resonant engineering XXX 18" sub for $1700, and you can order it with 8 ohm voice coils. Variable impedance is merely a means of constructing your specific application to meet the impedance needs of you amplifier. If, for example, you were running one sub, you would want a 2 ohm coil(if we're talking single coil) depending on the stability/class of your amp and plans for bridging. However, if you plan on running 3 subs, 2 ohm coils would have to be wired in either a 6 ohm, or a 1.3 ohm configuration. One would be way too high, and the other too low for most amps. 8 ohm coils on the other hand, could be wired in parallel at 2.6 ohm, which most mainstream amps are fine to run at. Its just a tool for configuration. A person needs to research and purchase an amplifier with a certain power level in mind, before using Ohm's Law to calculate the proper voice coil requirements and order the subwoofers.

Once again, it's awesome you took the time to do this. I wish there were more people like you taking time to share experience all over the place. Just a few things for discussion. I've designed and installed home, car, and marine audio for pushing 15 years, so I thought I'd add to your stuff. Now you get to go through mine and find my mistakes!

 

[keith4216]

Exactly, but I just couldn't type that much in between drinks. lol Once again good info just a debatable issue with many factors.

 

[thaphillips]

My post was written with the idea of spending a very meager budget on a system (around $500). I am sure you guys could put together a stereo system for 2k+ that may sound better.

Also my post was written with the idea of have a system that doesn't drain your battery.

As for the Cerwin Vega amp, if you haven't used it you may want to refrain from commenting on it. Or you could post to www.caraudiomag.com and pick apart their review.

 

[rhino1653]

Once again, Im not trying to flame anyone here. Just saw alot of incorrect info and thought things should be clarified. Not trying to offend. Bottom line on the CV amp has nothing to do with its quality. It just isnt enough. Numbers dont lie and it simply isn't enough amp to support 90% of peoples stereo needs. 2 highs and a small sub is all it could run. Not trashing on the amp, simply stating it doesnt have the power to run a couple sets of 6x9's/6.5s and a sub. Not even close.

 

[alwaysredee]

Everyone is ROCKIN' this thread and that is great to see! The best piece of advice remains: it's all about application! What do you want to hear, and what are you listening to it in! Great job, everyone!!!!

 

[thaphillips]

Bottom line on the CV amp has nothing to do with its quality. It just isnt enough. Numbers dont lie and it simply isn't enough amp to support 90% of peoples stereo needs. 2 highs and a small sub is all it could run. Not trashing on the amp, simply stating it doesnt have the power to run a couple sets of 6x9's/6.5s and a sub. Not even close.

You could run the four highs
(4 ohm) speakers in parallel and get a dual voice coil sub (4 ohm). There you go by wiring the highs in parallel it will drop the 4 ohm speakers to 2 ohm thus doubling the wattage. By getting a DVC (dual voice coil) sub you could hook it up to the two left over channels. The sub would run at 4ohms.

I would just like to add that the number of watts a manufacturer claims is not always accurate. So you can't just look at the side of a box and say it's not going to work. If you pick a sub that is effecient you should get pretty good bass.

So four speakers in parrellel on channels 3 & 4. The one DVC sub on channels 1 & 2. So six speakers. I think most people here would be happy with 4 speakers and a sub.

Remember at the beginning of the post I stated I was trying to avoid a big weight penalty.

 

[thaphillips]

Once again, Im not trying to flame anyone here. Just saw alot of incorrect info.

So what is incorrect?

 

[rhino1653]

So what is incorrect?

OMG! I'm not gonna flame. I'm not into internet arguments. But I have got to tell you man, you're making this extremely hard. You seem to know some, but are terrible at math, or have no understanding of Ohm's Law. 4 4 ohm speakers in parallel would show you a 1 ohm load before bridging. that .5 Ohms if you run bridged. Not capable. If you ran 2 in parallel left, and two in parallel right, you would supply 40-50 watts per speaker. That's less power than a cheap head unit supplies. You're right, the numbers on the box aren't always right. They're generally inflated, which means you can look forward to even less power than I'm describing. A DVC 4 ohm sub would not show 4 ohms, unless of course you were stupid enough to hook it up with a coil on the left channel and one on the right, which would fry both coils in no time flat. I assume you realize that running two separate signals to voice coils within the same assembly will cause a problem. If you were to series the 4 ohm coils(which I hope is what you're talking about) and bridge the 3-4 channels, you would see 4 ohm, and you would supply about 100W to your sub. Not worth the time. I'm done talking about that amp. It will work for some peoples applications. Not for most.

As for what was incorrect. See my original post. I used the word "wrong" several times. That would be the term I chose to signify error.

 

[thaphillips]

1. Class A/B amps are used for mid and high frequencies where SQ is concerned because the are designed to reproduce more of the input Sin Wave for use on the output side than a D class amp.

2. Memphis makes the Memphis Belle, which is a hybrid combining an A/B 4 channel that can efficiently supply 100W to four mid/highs and a D class that is 1 ohm stable capable of powering 2-3 subs if one so chooses. It can be found online for 400ish.


2. Having more power than you listen to will drain the battery faster. Wrong.

3. Sound quality is more about the amp than the head unit. Wrong. You can have the nicest amp in the world playing through $10,000 worth of speakers with a sh*tty input signal, and you will hear a sh*tty output signal.

5. Suggest putting speakers in boxes. While I don't disagree completely, it's just not feasible to do in most setups.


7. 2 ohm Subwoofers are better constructed and offer more performance. Couldn't be more wrong.

1 - A/B amps are not as efficent as class D amps. Go run 1,000 watts on A/B amps in the lake with one battery. Tell me how you like rowing back.

2 - Your Mephis Bell Amp is almost the price of the whole system poster earlier.

2 - Okay so if a bigger amp doesn't draw more power then why does it need a bigger fuse? Go put the 20 watt amp from the CV in the memphis bell and let me know how she powers up. Hey guess what alot of outboards have 20 amp altenators. Hmmm was that a coincidence or did I suggest the Cerwin Vega for a reason???

3 - Here we go again. $400 amp + $300 stereo. Your system will cost more than my whole boat. Why don't we just get some 26's for the trailer while we are at it. Obviously when you spend alot more freakin money your going to have a better sounding system. Read my first post which gives the application of my whole post, before you start build systems that cost more than my boat, and I can only run on a single battery for 15 minutes till it's drained.

5 - Read my post again, or are you just throwing this one in to make your "argument" appear bigger?

 

[thaphillips]

OMG! I'm not gonna flame. I'm not into internet arguments. But I have got to tell you man, you're making this extremely hard. . You're right, the numbers on the box aren't always right. They're generally inflated, which means you can look forward to even less power than I'm describing.

Have you every used this amp? Have you ever heard this amp? Unless you have used a product yourself, you really don't know much about it.

 

[john lamon]

 

[keith4216]

Don't get your panties twisted! I told you this was a debatable issue and theres no one way about it. You choose an issue to post that has so many variables, its gonna get lots of opinions. And until I grew up all my stereos and rims were worth more then my ride!! Maybe you should have just named your post differently, "Great stereo info for o/bs on a budget".