Archive for December, 2010

JL Audio Subwoofers: Loud and Live Sound Quality Bass

Friday, December 17th, 2010


JL Audio Subwoofers

JL Audio advertisements in the local and foreign magazines never fail to impress me. It is often featured with r&b celebrities etc. At first glance, it is just another good looking subwoofer in the sea of subwoofers available in the market place. Then we started experimenting with JL Audio subwoofers in our own rides and in customer’s rides using various enclosure configurations in varying vehicle dimension (small-large) and shapes (convertibles-hatchback-sedans-MPVs).

It is by far the most linear sounding subwoofer we have used in our installs. It sounds great at low volumes, medium, high and insane volumes with very good dynamic range. Rich sounding, hits hard when required and is not lazy sounding nor quick and lightweight sounding like aluminium ones. There are some monstrous subs that may sound louder but subwoofer to us is not entirely about how loud it can go. It needs to sound good and not be intrusive or missing at low volumes. Most importantly, to achieve the desired lows, we feel that subwoofers must be fed with the right signal in the first place to harness the best out of them. At Audio Creations, we know how to condition the signal that is fed to your speakers, and in this context in particular, to the ultra-low transducers – subwoofer. Power itself is not the only factor.

JL Audio subwoofers are well engineered and we rate its performance simpy as  ’low distortion’. It doesn’t give us any more loudness or lows that we really need or lack of any. It gives bass a good foundation!! Hard to fault. Bass delivered is clean, powerful and unobtrusive. It may not be the most accurate sounding subwoofer I have encountered over 12 years but it doesn’t colour the sound in any way. It just blends in well with a tuned front stage. Many subs simply cannot keep up with the front. There were numerous cases we found their 8 or 10s sound better than many 12 inchers.

We like JL Audio. The company takes the trouble to make sure the product line improves and improves further over time with newer models. Look at the amount of new patents that go into their designs. Well, okay it may be a little commercialized but it sure doesn’t look bogus. By the way, check out their Phantom subwoofers for home audio and home theatres. Clearly tells us they are serious about subwoofers and not just another over commercialized brand name. It is rugged enough for our installs; built quality is good and most importantly they sound great and does not break your wallet.

Furthermore, the documentation between the website,, and the owner’s manual is one of the best most of us have ever seen. Not only did the owner’s manual provided technical information, it has well-illustrated enclosure recommendations and an easy to understand power handling reference chart. In you are building your system for Loud Sound Quality in mind…  Go linear sounding, Go JL Audio!

Stinger Deep Cycle Battery For Your Car Audio

Friday, December 17th, 2010

Stinger SPV44

Power Series 660Amp Dry Cell Battery

The Power Series SPV44 is a valve regulated, sealed lead acid (AGM) battery utilizes dry cell technology  with an absorbed glass mat. The SPV44 is excellent deep cycle battery in a compact size, which is ideal for car audio applications.

SPV Series Batteries are good for over 300 full discharge cycles. SPV44 includes removable brass battery posts for installation flexibility and excellent connectivity.

Internal resistance: <5mOhms = Ability to quickly deliver power. The lower the number the faster the delivery. Part or most of the loss in charging and discharging batteries is due to internal resistance. This is converted to heat, which is why batteries get warm when being charged up. The lower the internal resistance,  the better.  Slower charging and discharging rates are more efficient. Much of this loss of efficiency is due to higher internal resistance at higher amperage rates – internal resistance is not a constant – kind of like “the more you push, the more it pushes back”.

Typical efficiency in a lead-acid battery is 85-95%, in alkaline and NiCad battery it is about 65%. True deep cycle AGM’s like the Stinger Power Series can approach 98%.

An important fact is that ALL of the batteries commonly used in deep cycle applications are Lead-Acid. This includes the standard flooded (wet) batteries, gelled, and AGM. They all use the same chemistry, although the actual construction of the plates etc. varies.  Stinger batteries are built solidly to last.

Constant discharge capacity at 77 degrees F (-25 degrees C) to 10.5V

20 hour rate: 2.2A/44.0Ah

5 hour rate: 7.48A/37.4Ah

1/2 hour rate:55.0A/27.5Ah

5 Second Cranking Amps (Burst): 660A


Watts: 1320

Peak Discharge: 725 Amps 5 Second Burst

Weight: 36.52 lbs.

Dimensions: (6.75H x 7.75W x 6.5D)

Comes with black powder finish protective steel case for extra protection and great cosmetics

Sealed design and can be mounted in any position. Stinger SPV Batteries are safe to be used in the car cabin without fumes.

A little about Deep Cycle Technology

A deep-cycle battery is designed to be regularly discharged to most of its capacity. In contracts, regular starter batteries (the ones that come with the car and sold everywhere) are designed to deliver sporadic high current for cranking the engine, and to be frequently discharged of only a part of their capacity. While a deep cycle battery can be used as a starting battery, the lower “cranking amps” imply that an over-sized battery may need to be used. However, in Malaysian local hot weather and high temperatures, there is less need for high cold cranking amps for firing up your vehicle’s engine… explained later on. Furthermore, most Malaysian cars are built with smaller capacity engines between 1500cc-2000cc and current production cars are designed to be very efficient and use smaller battery for cranking purposes.

The structural difference between deep cycle batteries and starter cranking batteries reside in the lead battery plates. Deep cycle battery plates are thicker, active plates, with higher-density active paste material and thicker separators. The thicker battery plates resist corrosion through extended charge and discharge cycles. Capacity of a new, maintenance free, or sealed, deep-cycle battery is designed to be limited by the amount of electrolyte in the battery, which protects the plates. This means that when it is end of life, it is end of life… similar to regular maintenance free batteries.

Regular starter batteries are not made for deep discharge. The lifespan decreases significantly on deep discharge. Deep cycle batteries are made for that purpose but due to the hefty price tag, we must be wondering how long it lasts. The lifespan of a deep cycle battery will vary considerably with how it is used.  There are so many variables, such as depth of discharge, maintenance, temperature, how often and how deep cycled, etc. that it is almost impossible to give a fixed number but on typical use for deep cycle services (use of aftermarket car audio and electronics), we expect it to last much longer than a regular starter battery, perhaps 2 to 2.5 times longer.

This is an indication of battery type and lifespan, taken from a technical website:

Starting: 3-12 months

Marine: 1-6 years

Golf cart: 2-7 years

AGM deep cycle: 4-7 years

Gelled deep cycle: 2-5 years

Deep cycle (L-16 type etc): 4-8 years

Rolls-Surrette premium deep cycle: 7-15 years

Industrial deep cycle (Crown and Rolls 4KS series): 10-20+ years

NiFe (alkaline): 5-35 years

NiCad: 1-20 years

Using a deep cycle battery as a starting battery

There is generally no problem with this, providing that allowance is made for the lower cranking amps compared to a similar size starting battery. With modern engines with fuel injection and electronic ignition, it generally takes much less battery power to crank and start them, so raw cranking amps is less important than it used to be. On the other hand, many cars, boats, and RV’s are more heavily loaded with power sucking “appliances”, such as megawatt stereo systems etc. that are more suited for deep cycle batteries. I have personally use Stinger Deep Cycle AGM batteries my previous VW Golf mkIII 2Litre Gti and another friend on his Toyota Wish with no problems for many years and could still sell them for ½ the price rather than dispose them after a few years. In short, it will not hurt a deep cycle battery to be used as a starting battery, but for the same size battery they cannot supply as much cranking amps as a regular starting battery which is not particularly important in a warm climate (the warmer it is the higher the amperage).

User Comments/Reviews:

-    This battery does a much better job than the stock battery. I used to get horrendous head light/interior light dimming when the bass notes hit with the stock battery. With this battery that was almost eliminated. If I really look I can detect a dim when the bass really hits but for the most part the battery performs. Only thing is I probably should have spent the extra money & stepped up to the next size Stinger battery. (we recommend adding a second unit, which adds up to much higher capacity compared to stepped up models)

-   Great battery. Great price.. The battery is totally sweet. My stock battery was lacking in juice but not this battery. With the stock battery my car’s built in electronic compass display would just shut off (probably not enough power to run my amps plus all my car’s electronic systems) but I’ve had the SPV44 installed for 2 weeks now & the compass display shows up on every crank. This battery also reduced my interior light dimming problem. Now I’m thinking maybe I should add another.