LIS Audio February Feature: Benefits Of An Upgraded Audio System!

Introduction

Have you ever wanted to see just how beneficial audio upgrades can be without having to purchase and install all of the components of a sound system to hear the differences? In this blog we will cover the benefits of simply adding new aftermarket speakers while upgrading the stereo system, and/or adding an aftermarket sub-stage. We will also go into some detail about the advantages of adding an aftermarket amplifier to newly installed aftermarket speakers. We will then display pictures of the Real Time Analyzer (RTA) measurements to show the difference across the full system from factory to fully upgraded aftermarket audio system breaking down each section as we go.

We had a client approach us about adding his new Pioneer Touchscreen, a couple of subs, and an amplifier, he had already purchased, to his 2014 Toyota Tacoma. When he arrived at LIS Audio for a free consultation we first evaluated the product to make sure all necessary parts we present and that we ordered the parts necessary for the job. Knowing that the new amplifier and sub setup would generate a good deal of bass, we suggested adding a speaker amplifier and then replacing the door speakers to allow the front-stage to become “louder” to keep up with the sub-stage. We also recommended adding Hushmat sound deadener, while we are in the doors, as to fully utilize the new mid-bass drivers. Check out what we did, and the results we found!

Factory Stereo Testing

The first test we performed on the RTA was to see what the overall ambient noise of the trucks cabin while all closed up. Most of the ambient noise in the shop derived from the sound of the heater, which remained constant throughout the experiment. We wanted to gather a bit of data before adding the auto sound deadener so that we can see how much the ambient noise is reduced, or if the truck cabin resonates the same, with the addition of the deadener. As you can see by the pictures below, the truck is fairly quiet but still has some room for adding sound deadener to reduce the ambient noise from the exterior environment.

In this next step we turn the vehicle on and play a Pink Noise track through the factory stereo system, with the equalization adjustments set to flat, and then monitored the RTA measurements. We set the volume on the touchscreen radio to 40, which was a very decent level but not too loud as to begin to hinder the system in any way. Our RTA “microphone sensitivity input” stays consistently set to 36 dB throughout the entire data gathering process.

Using our AudioControl DM-RTA measuring tool and AudioControl CM10 microphone. For those that may not know, a RTA is a spectrum analyzer that measures amplitude versus frequency (X vs. Y plot) of an audio signal while in real time. On our computer we will be able to physically see where the stereo system performs more prominently, or weakest, from 20 Hz up to 20,000 Hz. If you are not familiar with how to read the measurements on an RTA, or are not familiar with the subject of audio frequencies, I suggest you start doing some research into these subjects before continuing this article. 20 Hz-20 kHz is the range of human hearing.

We can see in the readings taken, after the sound deadener was added to the vehicle, they show the natural ambient noise level of “exterior environmental factors” to have decreased. It also seems some the frequencies above and below the “peak” of the bands have begun to thin out significantly, with a small overall reduction in the peak noise all the way across. It’s also visible that much of the noise at the frequencies that seemed barely prevalent in the readings, have disappeared altogether. Looking closely before the ambient noise was easily visible from about 125 Hz to 300 Hz, and after it seemed to be between approximately 140 Hz to 250 Hz with reduction in overall decibels.

The factory speakers were still in decent condition and did not seem to be deteriorating, yet did not perform as well as the aftermarket speakers, which was to be expected. Now that we see how the factory stereo performed, the components they used, and know what our ambient noise of the vehicle cabin looks like, lets get into the aftermarket side of it all. Starting with the list of products included in this installation…

COG (Clients Own Gear)

• Pioneer 6.2” Touchscreen AppRadio Receiver – COG
• PAC Audio RP4.2-TY11 Integration Kit (SWI-RC-PRO)
• Audio Dynamics 2000 Series Components Speakers
• Audio Dynamics 2000 Series Coaxial Speakers
• DS18 Candy Series 4-Channel Amplifier
• Hifonics Brutus Series BRX1516 Amplifier – COG
• Hushmat Bulk Kit

A Basic RTA Tune Difference

We adjusted the Pioneer stereo EQ setting “Custom 1” to flat. Then we set the Low Pass Filter crossover point to 120 Hz at -24dB slope on the front-stage, and the internal High Pass Filter 120 Hz with a -24dB slope on the sub-stage. This will allow the speaker amplifier to pass frequencies between 120 Hz – 20 kHz, and the sub amplifier to receive signal between 20 Hz – 120 Hz, which then gets further tuned with the amplifiers crossovers. After this, we did a “light tune” to attempt to balance the RTA EQ readouts to be as flat and even as possible. Which will be extremely minimal due to only having 13 bands (62.5, 100, 160, 250, 400, 630, 1k, 1.6k, 2.5k, 4k, 6.3k, 10k, 16k) of adjustment. The DM-RTA “Octave” setting was set to 1/12th and displays 12 readings per octave, which starts from 25 Hz and goes put to 20 kHz.

We set up the RTA microphone in the driver seat headrest area to get a response from the listening position that will be most often occupied. The goal is to find the highest areas of the RTA measured frequencies and adjust the stereo EQ at the nearest frequency sliders to the peaked frequency levels. For example; if we see the frequencies around the 80 Hz range to be spiked up much higher than the rest of the frequencies, we will grab the Pioneer 80 Hz slider and move it down until the frequency starts to even out to the same level as the rest, or as far as the slider will go. We did this with all of the available sliders in the Pioneer EQ to allow the amplifiers to play the new speakers as close to flat as possible read on the RTA.

These small adjustments made a huge difference in the natural sound and performance of the speakers when played at higher volumes. At this point, when we switch the Pioneer EQ from our Custom 1 setting to Flat, it sounds as if the stereo system is in a giant fish bowl. None of the other Pioneer default settings sound much better. After the quick tune using the RTA, the stereo system seemed to become much more vibrant and full. Sounds and instruments in the music become much more prominent, and the speakers appear to perform with much more ease across the tuned frequency spectrum. We showed the client these differences and his reaction was priceless! He loved it!

The Tacoma came with a factory back-up camera and steering wheel controls which we wanted to retain. We used PAC Audio integration pieces to properly integrate our aftermarket components into the Toyota seamlessly. Our client had already purchase the dash kit and it seemed to fit perfectly, so we utilized it. Overall the functionality the new components with the vehicle appear to almost be a factory upgraded option at first glance. Once the music starts to play it becomes apparent to be much more than just a factory upgraded system.

Aftermarket Speaker & Deadener Results

For this installation we went with our most popular 6.5” component and coaxial speakers for the front and rear doors. The Audio Dynamics 2000 Series component speakers are rated at 100W RMS and play efficiently between 60Hz and 20kHz depending on crossover slope adjustments. The coaxial speakers are rated to handle the same amount of power and play the same frequencies effectively. There are many things to consider when assembling the new stereo system components but we will mostly focus on the responses we can see and hear from factory to aftermarket components when installed.

The numbers when using an electronic high pass crossover; component set 60 Hz @ 24 dB/octave, 80 Hz @ 18 dB/octave, 100 Hz @ 24 dB/octave, coaxial set 60 Hz @ 24 dB/octave, 80 Hz @ 18 dB/octave, 100 Hz @ 24 dB/octave, 120 Hz @ 32 dB/Octave.

Before we get too deep into the this blog, if you would like to know more about proper speaker installation, read up on the process at Properly Installing New Speakers. If you would like to know more about auto sound deadener, learn up on its advantages in the LIS Audio blog The Benefits of Auto Sound Deadener. We used the proper techniques to install the speakers and Hushmat into the doors before testing, and it may be necessary for you to know just why we are using these specific techniques. If you’re familiar, read on!

We can see from the RTA measurements in the picture that the output of aftermarket speakers has increased in some areas and decreased slightly in others, getting us a bit closer to an audibly flat reading on the RTA mic. Granted, the bands are consistently in motion while capturing our results, so they may vary slightly up or down. Also notice how there is little to no low end as it starts to taper off hard at about 140 Hz. It is very apparent in the graph, and to our ears, that the new speakers made a substantial difference. Once we add properly adjust the input sensitivity of the amplifiers and tune the crossovers, the music played will become much louder while remaining clean (un-distorted). Now we’ll get into a bit of the sub-stage and tuning the system.

Touching on Bass, the Sub-stage

Our client brought in a pair of new Alpine Type-S 10” subwoofers and a Hifonics Brutus amp to power them. The way we wired the amplifier up should give the subs a solid 720W RMS of power, give or take a few Watts due amplifier efficiency. We calculated the overall amount of power the factory electrical system could theoretically handle, combined with the additional load added by the new sub amplifier, and speaker amplifier. The Tacoma seemed to be about 25-50 Watts over the limits of the electrical system with the added draw. I recommended to the client that we perform the Big 3 Upgrade. It is important to factor the draw of the sub-stage due to it being the majority of the newly added power consumption.

If the charging system is not sufficient and the system is turned up we may these signs; light dimming (headlight dim is typically pretty obvious), the system sounding muddy or breaking up on large long bass notes, and amplifiers overheating. Even though we were just on the cusp of needing to upgrade the charging system, we went ahead and added T-Spec 0 Gauge OFC wire on top of the factory charging wires to help provide more potential current flow to all components. We also built a custom ABS bracket that fit factory mounting holes in the engine bay to secure the fuse holders as to prevent any unwanted issues with the power wires. If you would like to know more about the Big 3 Upgrade and it’s added benefits, read the blog Explaining The Big 3 Upgrade.

The below images show some of the readings taken while the engine idles before and after the Big 3 Upgrade was performed. At rest, engine turned off, the batter would measure 12.5-12.8 Volts. Prior to the upgrade we an see that the voltage is in the mid to low 13V range, ~13.78V at the battery and ~13.06V at the amplifier terminals. After the upgrades we will see that the voltage jumps up to ~14.13V at the battery and a solid ~14.10V at the amplifier terminals. When we sat in the vehicle and listened to the stereo at it’s full safe output level the Voltage never dropped below 13.78V while the engine idled. This gives us a much more efficiently running electrical system, which means less chances of introducing distortion and more power to our components.

The client brought a subwoofer enclosure that fit a Toyota Tacoma but did not fit his current model, so we opted to custom build the enclosure. Due to the limited space behind the rear seat (which is where our client preferred the sub enclosure to be) we designed the enclosure to be sealed, as well as safely hold the new Hifonics amplifier on what we refer to as an “amp rack.” If you would like to learn more about the differences in subwoofer enclosure alignments (sealed, ported, 6^th order) then read the LIS Audio blog, Comparing Enclosure Alignments with Chimpo.

If you would like to learn more about the different enclosure alignments and the benefits of each, read our LIS Audio blog “Comparing Enclosure Alignments with Chimpo.”

Since our client already bought the subwoofers new, and they were just shallow enough to fit in an enclosure behind the seat, we decided to put in a bit of extra work into designing and building the enclosure. As to avoid having to purchase new shallow mount, or smaller full linear subwoofers. When looking through the enclosure build pics you will see that the baffle is double layered for rigidity, and to allow the subwoofers to be counter sunk further away from the back of the seat. We also added internal bracing between the subs for additional rigidity. You will also notice that we created small cavities in the rear interior wall of the enclosure so that the subwoofers magnets would not touch, and would allow them to fit properly.

The 10″ Type-S subwoofers performed really well in the sealed enclosure and produce a surprising amount of bass. A bit of “polyfill” was added to the interior of the enclosure to give a larger “feel” of the inner volume for the subwoofers. The overall sub-stage sounds great and as you will see it gives the full system plenty of contribution to the overall low end frequencies played in the music our client will be listening to. Let’s wrap it all up!

In Conclusion…

The DS18 Candy X4 4-Channel amplifier is installed in the storage area located under the rear seat, as requested by the client. The speakers are all wired up to a 4 Ohm load on each channel, which specifications say produce 80 Watts RMS each. This 4-Channel amplifier powers all of the front-stage speakers letting us achieve a higher volume of music while still remaining clean. The front speakers remain at 4 Ohm due to them being separated through passive crossovers.

The addition of the _Channel amplifier gives us a bit more head room to allow for us to adjust the front-stage EQ to balance out closer to the levels of the sub-stage, which seems to be much more impactful. Taking into account that the RTA readings in this article are measured at a decent-to-reasonable volume level, and not at full tilt, we can see just how much bass is produced from the subwoofers over the front-stage when our bass knob is turned all the way up. A ton in comparison!

The RTA image labeled with “1/8th Sub” indicates the bass knob is at 1/8th rotation to full, while the image that is labeled “Full Sub” indicates that the bass knob is turned all the way up. The sub-stage “seemed” to be audibly the most even with the the bass knob at about an 1/8th of a turn and was still appeared a bit higher when read on the RTA. We can see that the frequencies the subwoofers are tuned to cover are literally off the charts when turned up. Essentially, what we are seeing here, is that we have plenty of extra bass on demand for those songs with less bass, and the ability to turn it down a bit with songs that have lots of (too much) bass. Without distorting our system or sacrificing quality for higher volume levels.

Overall, these are not the most ideal components for a full installation but, we wanted to show that when installed and tuned properly you can have a pretty decent stereo system. We’ve used Pioneer stereos in the past with great success and we know the Brutus amplifiers to be able to produce a decent amount of rated power, so this made for a good feature to show these changes in upgrading the stereo system. It is important to account for all of the variables we’ve covered here in this article to get your system to a desirable and reliable state. Our client was not entirely sure what to expect from the full installation but he vocalized just how glad he was to come to us to have the work done because of all of the small details we’ve covered here. And we love to hear that!

Thank you for reading our LIS Audio blog and be sure to stay tuned for more to come! We will be writing up plenty of material on car audio education and client features in the near future. Our next feature could be your vehicle!

Phone: (913) 912-6990

E-mail: info@lisauido.com

Address: 631 S. A-Line Dr. Spring Hill, Kansas, 66083

Website: http://www.lisaudio.com

All images are provided and owned by LIS Audio (Limitless Innovative Solutions, LLC) of Kansas City.