Mobile Edge Tests The Real World Output of 2 Amplifiers

November 30, 2011 By Mitch 2 Comments

Memphis PR1X1000 Amplifier. Manufacturer claims this amp puts out 1000W @ 1 ohm , 580W @ 2 ohms and 320W @ 4 ohms

Boss CX2000M amplifier. Labeled as a 2000W amp, Online retailers claim an output of 1000W @ 2 ohm and not stable at 1 ohm.

Rarely does a week go by that we don’t have a customer bring in a “monster” amp and wanting a wire kit or subs to go with it. Printed clearly on the amp are the words 1000 WATTS or 2000 WATTS. We’ve even seen “5000 WATT” amps! Usually these amps were purchased at a truckload sale, flea market, or discount superstore. They are typically very inexpensive, usually under $150. Do you think that these amps can produce 5000, 2000 or even 1000 watts? Mobile Edge recently tested one of these “2000 Watt” amps from a company called Boss along with a Memphis PR1x1000 amp and we had some eye-opening results!

Amplifier Fusing

The Boss CX2000M Amp is fused at 50 amps

Without switching on our Oscilloscope we could clearly tell you that the Boss amplifier is not capable of producing even the 1000 Watts that the manufacturer claims. How do we know this? All you need to do is look at the fusing. Fuses are designed to limit the amount of current that the amplifier can take in (in part to protect the amp). Simple physics says that if the input is limited, so will the output. The Boss CX2000M is fused at 50 amps. Using the formula below, you will find that the amp could not produce more than about 405 watts of sustained power. The formula for determining power is:

$Total Power = DC Volts \times Current Draw\times Efficiency Constant$

For our purposes, we will use a DC voltage of 13.5 which is typical of a vehicle’s alternator (and will be referenced below). AB Amplifiers typically are between 50 and 60% efficient. We can give the Boss amp the benefit of the doubt and go with 60% Plugging in the numbers we get:

$Total Power = 13.5 \times 50\times .6$

Under most circumstances, this amplifier could not produce more than 405 watts for a sustained period without blowing fuses. This is quite a bit less than the 2000 watts on its label!

The Memphis PR1X1000 Amp is fused at 120 amps

Moving on to the Memphis PR1X1000 amp you can see that it is fused at 120 amps.

For class D amplifiers, you use an efficiency constant of about 80%

Assuming the same input voltage of 13.5V and 120 amps of current draw, we can plug in the numbers:

$Total Power = 13.5 \times 120\times .8$

The maximum sustained power that the Memphis PR1X1000 should be able to produce before the fuses blow is about 1296 watts. Nearly 30% more than the manufacture specifies.

Testing Equipment

Power Supply

1000 CCA battery

There are several tools that are needed to properly test the output of an amplifier. First of all, you need a solid power supply. We’ve got this covered with a 50 amp Power supply charging a series 31 1000 CCA farm and truck battery. This setup gives us the power we need to test all but the largest amplifiers without worrying about significant voltage drops.

TPI440 Oscilloscope

Fluke Digital Volt Meter

We use a TPI440 Oscilloscope to see where the signal clips and read the voltage just before clipping. This gets connected to the speaker outputs of the amplifier. A Fluke Digital Volt Meter is used to measure and monitor the input voltage throughout the testing. These units are considered industry standards and are used on a daily basis at Mobile Edge. They are used for everything from system setup to circuit testing and signal identification when doing OEM integration work.

Test Bench w/JVC deck

Fluke Digital Volt Meter

We use a standard JVC cd player to supply the signal. Our test bench has a complete Ohms Law pie chart for quick conversion of volts, amps, watts, etc! Test tones are generated by the CD104 Test CD. This disc has been used since the early 90′s for system setup. For our test on these amplifiers we will be playing a 40 hZ test tone. Every good shop has at least one copy of this CD if not more!

1600 Watt Dummy Load

This is a custom bank of 16 four ohm, 100 watt resistors. We have 4 banks of 4 resistors each and they can be wired to derive a 1, 2 or 4 ohm load. This “dummy load” does a decent job of simulating a speaker. While a speaker is a reactive load and this is not, it gets us into the ball park. We have it mounted to a 3/8 piece of aluminum to help disperse heat. When used for a time, these guys get hot!

Aside from testing amplifiers, we use this during system setup. It takes the place of a speaker during the earlier stages of tuning. This way we don’t need to be blasted out for hours while setting up a system not to mention it allows the new speakers to be broken in more gently!

Amplifier Testing

The first thing that we do to test the amplifier is to determine the clipping point of the head unit’s RCA leads. We want a strong undistorted signal going to the amp. Once we find the clipping point of the deck, we back down the volume slightly until there is no distortion. The amplifier testing is done with the volume set at this level. (Note that this step was not shown in the above video but described in this link)

We use the CD104 test cd and set it for the 40hZ track. The CD player is set to repeat this track over and over.

After hooking up the amplifier, we set the gain to minimum, crossover point to about 100hZ and all subsonic filters and bass boosts to off/min. The amplifier is connected to the dummy load. In the case of the Boss CX2000m amplifier, we wire the load for 2 ohms. The manufacturer states that the amp is not stable at 1 ohm thus producing max power at 2 ohms. For the Memphis PR1X1000, we wire it for 1 ohm since this amp is stable at 1 ohm.

The next step is to test the supply voltage. In each case, the input voltage tested at right around 13.5 Volts. This is a very common voltage range found in vehicles while running.

Finally the oscilloscope is hooked up to the speaker outputs of the amp and set for AC voltage (speaker outputs are AC). The Oscope will show the frequency, in this case 40hZ along with the voltage. It also shows the waveform being generated by the amplifier.

We slowly turn up the gain control on the amplifier and watch the waveform. Eventually, the waveform will start to distort or flatten out. This indicates distortion or clipping and that the signal is no longer clean. We back the gain off slightly until the waveform is clean again and read the voltage.

In the case of the Memphis amplifier, the undistorted voltage was 34.9 volts.

This formula for power is simple and the same whether Class AB or Class D:

$Power = \frac{{AC Voltage}^2}{Impedance}$

$Power = \frac{{34.9}^2}{1}$

(Test was done with amp wired to a 1 ohm load)

Do the math and you will find that the Memphis amp produced 1218 watts. That is 121.8% of the power that the manufacturer states in their literature, manuals and website.

The Boss amp did not fare so well. When tested, it produce an undistorted 25.11 volts.

$Power = \frac{{25.11}^2}{2}$

(Test was done with amp wired to a 2 ohm load)

Again, do the math and the 2000 Watt Boss CX2000M amplifier produced a whopping undistorted 315 watts! Doing a little more math and you will find that this is only 15.75% of the power that is stamped on the amp and only 31.5% of the power that the manufacturer claims!

The Insides of the Amplifiers

We thought it would be interesting to take the amplifiers apart and see what they looked like inside. The CX2000M is much larger and noticeably lighter than the Memphis PR1X1000.

The Memphis PR1X1000 on the Left and the Boss CX2000M on the right. Both have the lids off to expose the insides.

It is easy to see that there is a lot more going on inside of the Memphis amp. There is not a lot of space. That is not the case with the Boss amp. Inside the CX2000M you’ve got plenty of room!

Memphis PR1X1000 Opened Up

Boss CX2000M opened up

Amplifier Testing Conclusion

This post and test was not meant to put down any specific amplifier. The only reason that we used the Boss amp was because a good customer had one lying around and volunteered it’s use. The purpose is to point out that not everything is as it seems in the world of car audio. There is no required governing body for car audio ratings. There are no testing laboratories that manufacturers have to send their equipment to. Any manufacturer can claim any power rating that they want. It’s that simple. (It is important to note that there is an industry standard called CEA 2006-B. Manufacturers are not required to take part in it. When comparing 2 amplifiers that are rated by CEA 2006-B guidelines you can get a good apples to apples comparison. Also, almost all of the reputable industry manufacturers use Cogent Laboratories in Chandler, Az for their testing and independent validation.)

The Memphis amplifier clearly puts out nearly 4 times the power of the boss amp yet both manufacturers claim 1000 watts. The Memphis amp exceeds this rating and the Boss amp barely puts out 30% of the claim. When making a purchasing decision, it is important to understand the quality of the product you are buying. It is important to trust the product and the retailer you are buying from.

Imagine if the customer that bought the “2000 watt” amp decided to go out and get two subs that could really handle 1000 watts each. They would be wasting an obscene amount of money BIG subs and the end result would be very poor. What they really should get are two 150-200 watt subs.

I know that the argument can be made that the Memphis amp is more expensive than the Boss amp. This is absolutely true. A quality product that produces lots of power costs more money to build. If you look at typical street costs for each of these amps and do the math, you will see that the Memphis amp is much cheaper when you consider dollar per watt. Also important is the dealer selling the product. It is unlikely that the flea market vendor or discount superstore employee selling the “monster 2000 watt” amps will be able to provide the expertise necessary to design and build a great system. But I’d bet your local Memphis or Hertz/Audison dealer will!

All that aside, don’t you like the idea of getting 21.8% more than what you are promised?

I welcome your reasoned and well thought out comments!

Filed Under: Car Audio

Mobile Edge Owner Mitch Schaffer Attends JVC Dealer Conference in Temecula, CA.

November 14, 2011 By Mitch Leave a Comment

Every once in a while, business ownership throws you a perk. I had one of those perks last week when I attended the JVC 2012 Product Preview Meetings at the Pechanga Resort and Casino in Temecula, CA. Only a handfull of dealers were invited throughout the country and I was honored that we were selected.

Mobile Edge Owner Mitch Schaffer with JVC Vice President Bill Turner after a round of golf at the Journeys at Pechanga

It all started earlier this summer when Mobile Edge was featured in an article in Dealerscope magazine. One of the photos that was used showed our head unit display filled with JVC decks. A few days after the article was published I got a call from Bill Turner, Vice President of Mobile Entertainment for JVC. I’ve know Bill Turner from his days as National Sales Manager for Orion Car Audio back in the 90′s. He called to thank me for effectively supporting the JVC brand at Mobile Edge. We spoke for quite a while and I shared with him what we were doing with our website and with social media in our store.

It was about a week later when Bo Lamar, Eastern Regional Sales Manager for JVC, called and asked if I would be interested in joining them from November 9 – 12 in Temecula for the 2012 dealer preview. Of course I was interested! They booked the flight and reserved the room and last Wednesday afternoon I left for the airport. One cancelled flight and 12 hours later, I arrived at the resort.

This golf course was absolutely beautiful. Pictures do not do it justice. It is important to note that the incredible surroundings did not improve my golf game!

The resort was beautiful. It has a large casino that I tried very hard to stay out of and excellent restaurants and lounges throughout! The good folks at JVC took care of everything! They treated me like Mobile Edge was a 5 million dollar account (we’re not!!!!). They listened to my ideas and cared about what I had to say. On Friday, they treated me to the a round of golf at the Journey’s at Pechanga, rumored to be one of the top 5 public course in the country.

Never saw a sign like this on a PA golf course!

The product preview meeting was exceptional. I had to sign an NDA (non disclosure agreement) so I cannot mention specifics, but I can say that 2012 will be a tremendous year for JVC. We spent most of Thursday going over what the future holds for JVC and let me say that the future looks bright!

That evening at dinner, I had the pleasure of speaking with Chad Vogelsong, General Marketing Manager for JVC. He is the brains behind most of their marketing efforts including the 60+ regional Facebook Pages and the annual “Turn Me On” videos. We talked about how Mobile Edge and JVC can partner up on some Facebook promotions. Believe it or not, at 2300 fans, Mobile Edge is among the most popular Facebook pages for any car audio store in the country. Because of this, Chad felt that Mobile Edge would be an interesting testing ground for some of the promos that they plan on running. If you have not “liked” Mobile Edge or JVC PA on Facebook, be sure to do it now and be eligible for some great deals and giveaways coming up very soon!

This was a great opportunity for Mobile Edge and shows that some large companies really care about their dealers in smaller markets. If you are in the market for an audio upgrade, I recommend JVC and if you are in the area, I invite to to check out their lineup at Mobile Edge.

On the ride to the airport I saw the USS Carl Vinson docked in the San Diego harbor (You can see it in the background). The day before, the supercarrier that dropped off Bin Laden hosted a basketball game.

Filed Under: Bluetooth, Car Audio, IPOD Integration, Mobile Edge, Uncategorized

Major Amp & Subwoofer Event Going On Now At Mobile Edge

October 26, 2011 By Mitch Leave a Comment

Mobile Edge is known for the quality products that we sell and the expert installation that we provide. What’s even better than the best stuff, installed in your vehicle to perfection? Being able to buy the best stuff at big discounts, that’s what! We just stepped to the plate and made a huge purchase of amplifiers, subwoofers and enclosures. Possibly one of the largest orders we’ve placed in 10 years! Our vendors appreciate what Mobile Edge brings to the table and when we were ready to write the big check they stepped up with some insane discounts!

Now those discounts are being passed along to you! Imagine getting a Memphis amp and sub and a box for $149! We’re not talking about “Phony Explode” brand either! This is quality equipment. How about a matched pair (4 channel and a 500 watt mono amp) of Memphis amplifiers for $319? That’s $319 for 2 high quality amps and we’ve got 6 sets for sale! Two 12″ subs with a 1000 watt amp and ported enclosure for $299.. Got that too!…. 500 Watt Memphis Amplifier for $179? Stop in and see for yourself!

Everything comes with a warranty and in many cases that warranty can be doubled just by letting us to the dirty work and professionally installing your equipment in your ride! We even have special deals on amp wire kits!

The Fine Print: There are no rain checks. When they are gone, they are gone. Short term layaways are available. Some items are B-stock, but all items come with a warranty! Many packages are a one of a kind so get ‘em while their hot! These deals are available ONLY at the store. they are not available via internet or phone!

Check out this video with a small sampling of what we have available as of 10/26/2011. We have many other deals and specials available at the store! Stop in before it is too late!

Filed Under: Car Audio

Mobile Edge Demo Vehicle Retains Stock Appearance, Sounds Incredible!

September 13, 2011 By Mitch Leave a Comment

“Every great shop needs a demo vehicle to show off their products and installation abilities.” These were the words of an industry member that I respect a lot at a training earlier this Spring. His words really hammered home. There we were, 2010 Mobile Electronics Retailer of the Year and we didn’t have a store demo vehicle. We’ve had a lot of them in the past, but we haven’t had one to speak of for the last 3-4 years. Shame on us!

It was around this time that an ex-employee who now works for a chain of car dealers called me to let me know that they had just traded a vehicle “that I just might like!” The vehicle turned out to be a 2008 Lexus IS250. It was in excellent condition, had been serviced meticulously and the price was right. We took delivery of the vehicle a few days later.

The next thing that we did was to lay out a list of criteria that the demo system needed to meet. This is what we came up with:

It had to retain factory radio. This system needed to show off the capabilities that exist for factory integration.
The vehicle needed to remain as factory looking as possible. I wanted there to be very little, if any indication that an aftermarket system existed.
Sound quality was to be much more important than SPL. We wanted it to sound great and get loud if we wanted, but this was not going to be an ear-shattering system. Sound quality was the primary goal.

We spent the following week determining what we could do with this vehicle. As we learned more about it , we quickly realized that we had made the right choice. The front doors were equipped with 3 way component speakers. There was a woofer in the bottom of each door, a mid in the center and a tweeter in the top. The back doors housed a 2 way component set.

We also found that the vehicle was equipped with a factory amplifier located in the rear of the trunk. After spending a good deal of time with the oscilloscope and RTA, we figured out what each of the wires did. Turns out, the front doors were bi-amped. This meant that the amplifier was sending out low frequencies to the woofers and a shared mid/high signal to the mids and tweeters. The amplifier also supplied a sub signal to the factory “subwoofer” located in the rear deck.

This presented a small problem to us. In order to supply the amplifier with a full range signal, all of these frequencies had to be combined. Audison BitOne to the rescue! The BitOne is an amazing product that we will cover in detail in a future post. In addition to re-combining the audio signals, it acts as a multi-channel 30 band EQ, time alignment device, provides an auxiliary input (or 2) and is the ultimate line output converter (among other things). We’ve used plenty of BitOne’s before, but this time we were really going to put it through it’s paces. This vehicle was the perfect playground for the BitOne. As an added bonus, the DRC (remote control unit) for the BitOne fit nearly perfectly in the factory change holder to the left of the steering wheel.

When it came time to pick speakers, the decision was simple. We wanted the ultimate in high end sound from a 2-way system. That narrowed the search to the Hertz Mille MLK2TW 2 way component set. We mounted the woofer in the factory woofer location and the tweeter in the factory midrange location. Great care was taken to make sure the speakers were aimed properly for the best imaging possible. The back speakers remained stock and play off of the factory amplifier. There is a small twist here. The rear speakers would not be part of the main system. For critical listening, the rear speakers would be turned off completely. In the event that there would be a rear seat passenger, the rear speakers can be engaged to provide sound to the back.

Again, the sub proved to be an easy decision. We wanted very defined and clear bass. We also knew that this single sub would go into a small sealed enclosure in the trunk so it had to handle a good deal of power. This lead us straight to the Hertz HX250.5 10″ subwoofer. This sub handles power, works great in a small sealed box and sounds fantastic. A custom fiberglass enclosure was built into the driver’s side of the trunk. When you open the trunk, you would not know that the sub is there unless you were familiar with a Lexus IS250 trunk.

For amplification, we went to the Audison LRX5.1K. This 5 channel amplifier is an all in one solution designed specifically for bi-amped systems with a sub. Channels 1 and 2 provide 60 watts to each of the tweeters. Channels 3 and 4 send 170 watts to each of the doors woofers. A massive class D channel provides 750 watts to the subwoofer. These power ratings are for the way that we chose to configure the system. The amp can produce more power when being driven to lower impedances. We chose not to do this to maximize sound quality and system headroom.

At Mobile Edge, we believe in sound deadening and encourage it in all of our jobs. To be able to demonstrate exactly what proper sound deadening can do, we turned to Hushmat. Hushmat is a leader in vehicle sound control. We treated nearly every surface of the Lexus with Hushmat Ultra. Three of the doors were treated, inside and out. The driver’s side rear door was not treated with Ultra so that we could show customers the difference that it can make by doing a simple “knock” test. The difference is truly amazing. In addition to the Hushmat Ultra, we installed Hushmat Silencer Megabond in each of the 4 doors. What Ultra does for low frequency vibrations, Silencer does for higher frequency noises such as road and wind noise. When the vehicle was reassembled and we took it for the first ride, the noise floor difference was nothing short of astonishing! An already quiet car is now nearly dead quiet while cruising down the highway. Imagine what this did for the sound.

We installed a few other tricks into the vehicle:

We added Bluetooth handsfree that works through the factory radio and outputs through the vehicle’s speakers. This system is truly remarkable in both ease of use and sound quality.
A custom usb port was installed into the factory cigarette lighter location. Looking at the port, you would think that it was there when it left Japan.
An iStreamer device was installed to boost the output level and overall sound quality of an iDevice. In addition, the iStreamer will charge the device while it is in operation. We have used the iStreamer in several vehicles and find the improvement in sound from an iDevice to be remarkable!
We added an Audison 1.4 farad capacitor to improve overall sound quality of the system. This is recommended in most every system that we do.
We made a customer Lexan panel to go into the factory skihole location. It was engraved with “Mobile Edge 2010 Retailer of the Year” and backlit in red neon.

After the installation was completed, it came time to tune… and tune….. and tune some more. Fortunately, Mobile Edge has all of the necessary tools to toon any system the right way. We spent hours in the trunk with the Oscope getting the levels just perfect. Once that was complete, we moved on to the driver’s seat with laptop and RTA in hand. While the BitOne is a very complex and detailed device, it takes a lot of time to properly set it up. Crossover points need to be set, tested and changed. Each output channel has it’s own 30 band EQ. Time alignment has to be set up and then slowly dialed in to perfection and all of that is for the driver’s listening position. Much of this has to be calibrated specifically for other listening positions. In our case, we set up a passenger’s seat listening position for when we are demoing the system to clients. When it was all said and done, we probably had close to 40 hours of setup and tuning in this vehicle. It wasn’t until we were completely satisfied with the results that we announced the vehicle’s completion.

The Lexus rivals the sound of most high end home hi-fi setups. The imaging and staging in this vehicle are nothing short of amazing. The singer sounds as if he/she is hovering over the center of the hood. You can pick out the locations of the other musicians across the top of the hood. Fidelity and sound quality far exceed what you would normally come to expect from a high end car setup. Don’t take my word for it. Stop in sometime and take a listen for yourself. This is not a boom system, but I would submit that this very well might be one of the very best sounds systems that you have ever heard.

Take a look at some of the build pictures below. Click on any picture to open up the slideshow.

2008 Lexus IS250 - Hertz - Audison -Hushmat

Filed Under: Bluetooth, Car Audio, IPOD Integration, Mobile Edge, OEM Integration

Longtime Customer Outfits Nissan Rogue With High End Audio

June 16, 2011 By Mitch 2 Comments

Several years ago we did some work for a customer in a Ford Fusion. He wanted high end audio and learned about Hertz and Audison. When he found that there was a dealer nearby, he dropped in to audition the speakers. He was sold instantly and was amassed quite a system over the years.

When he recently decided to trade the Ford in on a fully equipped Nissan Rogue, one of his first stops was Mobile Edge. He wanted some ideas and Bob stepped to the plate and gave him some ideas and advice. He already had a fine list of components:

Audison SRX5.1 Amplifier
Audison SRX2.1 Amplifier
Audison BitOne Processor
Hertz HSK-165XL Component Speakers
Hertz Energy 12″ Subwoofers

With a bit of creativity, we were able to use all of this. Of course, we added a large dose of Husmat to the doors! The factory head unit had plenty of functionality including navigation so he decided to keep that and integrate it with the aftermarket system. This is very much inline with many of our recent installs that maintain the use of the factory radio.

The customer gave us a lot of creative freedom with this project. He had no issue with removing the spare tire and using that airspace for the subs and amps. We started with laying out the subs and amp. After we had a good idea where everything would go, we went to work on the fiberglass mold of the spare tire well. This took some time but allowed us to use every available cubic inch of the well.

We attached the mold to a framework and designed the amp rack. We stacked the small amp on top of the large one. We did this in such a way that the small amp appears to float over the SRX5.1. The subs were mounted on slightly angled panels toward the rear of the vehicle. All of this rose up barely 2 inches from floor of the hatch.

To keep the amps cool, we installed a crossflow cooling fan in an unseen part of the amp rack. This blow A LOT of air to keep the amplifiers running at their best.

The spice up the look of the hatch, we mounted white plexiglass around the subwoofers. To further enhance the appearance, we ran 30 inches of red ribbon LEDS behind the trim. When the system is powered up, they bathe the subs and amp in a warm red glow. Looks really sharp!

The only thing that we were unable to display was the real heart and soul of the system: The Audison BitOne. Because of space limitations, we had to hide the BitOne behind a factory panel. We felt that this was a good trade off in order to maintain the aesthetics of the install.

The doors were treated with a healthy dose of Hushmat Ultra sound damping. This is a MUST in any high end install. We believe that it will improver the sound of ANY speakers, but it is especially important in jobs like this. The last thing that you want when listening to a new system is to hear the door panel vibrate!

A lot of attention to detail went into this job. We didn’t take any shortcuts and the results, both visually and audibly are spectacular!

To learn more about the install, click on any of the pictures below to open up a slideshow.

Audison BitOne HiddenSince the rack will be in place before any wires can be run to is, Nick put a pull wire in place to make things easier later on.

Filed Under: Car Audio, OEM Integration

Suburban Philadelphia Customer Gets Killer Audio System

May 10, 2011 By Mitch Leave a Comment

Some people have very critical tastes in music. They demand the best quality both at home and in the car. A Philadelphia area audiophile recently did a search online to find a local Hertz and Audison dealer. He had listened to some other high end products at some other shops and now wanted to see what all the fuss was about with Hertz and Audison. Of course, he found Mobile Edge. After an email and a couple of phone calls, he decided to take the drive from the outskirts of Philadelphia to hear and see this great line of car audio for himself.

Front Stage

Bob met with him on a Saturday and they auditioned the variety of Hertz car audio speakers that we have on display. From the more cost friendly Energy (and now Dieci) series, all the way up to the MLK 2, Mobile Edge has most of the Hertz lineup on display. They spent a while listening to various types of music and the customer soon was entranced by the MLK 165 components. That was a done deal. MLK 165 components in the front. Because the rear speakers would not be amplified, the customer opted for the HCX165 coaxes in the back. Of course, all of these high end speakers would need and greatly benefit from sound deadening. Hushmat to the rescue!

Amplification

Bob played the MLK165 speakers with several different series of amplifiers. The audition quickly turned to the LRX amplifiers. Bob explained the extreme cool factor with the LRX5.1K amplifier. This amplifier is the king of single amp installs. It is designed with sound quality at the absolute forefront. Power is rated at 50w x 2 for the highs, 150w x 2 for the mids and 1150w to the sub! Because we were planing on bi-amplifying the system, this amp was perfect. While not an inexpensive amplifier, the power, quality and configurability of it makes it an easy choice for a system like this (In fact, this amp will be used in the Mobile Edge demo vehicle).

Subwoofer

This customer is not a bass head, but he certainly saw the need for a high quality “low” end to any system. The natural choice for the system was a Hertz HX sub. When it came time to decide between the 10 and the 12, the 10 won out because of the criteria to keep the system as low profile as possible. It looked like the Sub would fit perfectly in a custom fiberglassed enclosure in the rear passenger side of the hatch. The choice was made to use the HX250 subwoofer.

Connectivity and Power Supply

With a system of this quality, you don’t use cheap signal cables. The customer essentially left the decision to us and we chose the Audison Connection high end interconnects. They are extremely well made, twisted pair design cables that do a great job of passing the signal and rejecting the noise. For an amp this size, we needed some serious power. 1/0 gauge cable was used and the power supply was augmented with a 1.3 farad capacitor. Not only does the cap provide instant power during strong transients, but it also acts as a ripple filter on the power line. 1/0 ground cable was also used. Another cable was used to beef up the ground from the battery to the frame of the vehicle.

Installation

(Editor’s note: I’ll cover some of the high points of the install here, but you can get a lot more information by clicking on any of the pictures at the bottom of this post.)

The first day that the vehicle was in the bay, we went over final details and removed most of the interior panels. Bob ran the power and signal cables and mounted the capacitor next to the jack. The 1/o gauge was carefully routed through the firewall with a special grommet that we bought from a local auto parts store. We also beefed up the factory ground from the battery to the frame of the vehicle. This is a step that many shops ignore when doing high powered systems. Truth is, it is VERY important and can have a huge negative impact if not done.

The next day Nick arrived on the scene and took on the task of sound deadening. The doors in the Jeep use a special “pod” that houses the lock and window motors, wiring and the speaker. This had to be removed in order to get to the skin to apply the deadening. After some careful investigation, Nick and Bob removed the pod and Nick went to work installing the Hushmat. The midranges actually installed fairly easily in the doors once the pods were reinstalled. The tweeters found a home in the factory tweeter locations. All new wiring was run to the rear of the vehicle for future connection to the amp. After the speakers were installed in all four doors, Nick moved on to installing the Hushmat in the hatch and hatch door. Hushmat is a extremely effective deadener and is the exclusive brand of Mobile Edge.

Day three brought the biggest challenges. Nick began working on the custom box and Bob started wiring the amp. It became apparent to Bob that this amplifier was going to need some type of cooling. Being the creative fellow that he is, Bob fabricated a platform and vent for a crossflow pan and mounted it into the forward portion of the amp “enclosure” (actually the amp is mounted in the factory compartment that makes up the false floor of the hatch). The cooling worked like a charm. By the end of the day, Bob had the amp installed, the cooling system complete and the panels reinstalled.

While Bob was doing this, Nick was hard at work designing and creating the “facade” for the enclosure. The goal was to take up as little room in the hatch as possible. Nick accomplished this by building the enclosure into the passenger side of the hatch. He molded a facade for the box using the factory panel as a guide. This mold, along with the enclosure itself was wrapped in fleece and fiberglassed. After it was sanded down and test fit, it was carpeted. A perfect color match was not a priority of the customer so we did not go to the expense of ordering color matched carpet. Instead, we found a carpet that matched the interior of the door panels pretty close and used that. The end result was the box fits snugly, looks amazing and takes up very little space. Be sure to check out the pictures below for a better appreciation of this process!

System Tuning

The final day of installation was dedicated to tuning and cleaning up the vehicle. At Mobile Edge, we tune vehicles the right way. We don’t rely on our ears. We have specialized equipment that is necessary to correctly tune a system. The first thing that we do is use a test disc in conjunction with a polarity tester. This verifies that all speaker connections are in phase. Just one speaker out of phase can wreak havoc on a system. After that is verified, we move on to determining the undistorted output of the head unit. We do this with an oscilloscope. It is important to know the point at which the head unit distorts. We use this as a reference point for tuning the amp. Along with another special test disc, we move on to setting the gains on the amplifier. Many people think that a gain is a volume control to get more out of an amp. Nothing is further from the truth. The gain control is used to match the output of the head unit with the input of the amplifier. When set properly, you get better sound and help to protect the components from damage.

Bob spent a great deal of time properly tuning this system. It was all worth it. This system sounds absolutely incredible! The best part is, when you look at the vehicle, you don’t even know it is there.

Cleaning and Pickup

Bob thoroughly cleaned out the inside of the vehicle and washed it to get rid of any dust from the sanding and saw. At the end of the day, the customer arrived to pick up the vehicle. He was overwhelmed! While he had seen the pictures that we posted on Facebook, he had no idea what he was in store for when he sat down and listened to it. TIGHT bass.. CRISP highs and midrange that blended perfectly! He absolutely loved what he saw and what he heard! I do believe that Mobile Edge has earned another happy customer!

This is a quote that the customer posted on our Mobile Edge Facebook page the day after picking up his vehicle: