Tuesday, October 24, 2023

Old School MTX Thunder Bandpass Subwoofer Box - Sold at Circuit City

In this article, we will be taking a closer look at an old school MTX Thunder bandpass subwoofer box. This particular speaker box was sold at Circuit City back in the day and features two 10-inch drivers inside. We will examine the construction of the box, clean the interior, and explore the woofers. Additionally, we will discuss the specifications of the MTX Thunder subwoofer box and its compatibility with the MTX Blue Thunder Pro amplifier.

Introduction to the MTX Thunder Bandpass Subwoofer Box

I recently had the opportunity to acquire a unique speaker box, the MTX Thunder bandpass subwoofer box. A generous individual contacted me and offered this cool speaker box, and I couldn't resist. So, let's dive in and take a closer look at this vintage piece of audio equipment.

The MTX Thunder Bandpass Subwoofer Box

The MTX Thunder bandpass subwoofer box is a single reflex bandpass box that houses two 10-inch drivers. The box features ports on both sides and has a single terminal. Upon initial inspection, the box appears to be a little dirty on the inside, so I decided to remove the Plexi panel to get a better look at its construction.

Inside the MTX Thunder Bandpass Subwoofer Box

After removing the screws, I lifted the Plexi panel and was pleasantly surprised by its thickness. The panel is approximately a third of an inch thick and has a gasket seal all the way around, ensuring a snug fit. However, the inside of the box did require some cleaning, as it was a bit dirty.

Examining the Woofers

Next, I proceeded to take a closer look at the woofers inside the MTX Thunder bandpass subwoofer box. I carefully pulled out one of the 10-inch drivers and noticed that the wires connecting it were surprisingly small. The woofer itself appeared to be a standard model from that era, with a foam surround that had not deteriorated. However, the wiring was inefficient and insufficient, with wires that seemed to be around 20 or 22 gauge.

Upon further inspection, I disconnected the driver and observed some bugs and spiders on the back. It's a good thing there wasn't any spider activity inside the box. The wiring definitely needed an upgrade, so I decided to replace it with larger gauge wire for better performance.

Cleaning the Box and Reassembling

Before vacuuming out the box, I took a moment to examine the inside and noticed a date stamped on the interior. The box also had two and a half inch ports and a terminal cut with small speaker wires. After vacuuming out the box to remove dirt and dust, I reassembled it, using the original small gauge wires to keep it as close to its original design as possible.

Cleaning the Acrylic Panel

The Plexi panel of the MTX Thunder bandpass subwoo fer box had some scratches and dirt on it. To clean it, I used a product called Novus Plastic Clean and a microfiber towel. I applied the cleaner to the panel and gently wiped away the dirt and scratches. While some of the deeper scratches remained, the panel looked much shinier and cleaner than before.

Shop for Novus Plastic Clean on Amazon*: https://amzn.to/3Fy9P2t

Testing the Speakers and Amplifier

With the box cleaned and reassembled, it was time to test the speakers and amplifier. I used an MTX Blue Thunder Pro 1502 amplifier to match the vintage style of the subwoofer box. The amplifier was wired up with eight gauge wire and bridged for optimal performance. I used 16 gauge wire to connect the amplifier to the subwoofer box.

The sound produced by the MTX Thunder bandpass subwoofer box was impressive. The deep bass tones were best experienced with headphones or quality speakers, as computer or iPad speakers may not do justice to the audio quality.


In this article, we explored the MTX Thunder bandpass subwoofer box, a vintage audio equipment sold at Circuit City. We examined the construction of the box, cleaned the interior, and discussed the woofers. Additionally, we tested the subwoofer box with the MTX Blue Thunder Pro amplifier, resulting in a satisfying audio experience.

If you're interested in learning more about the MTX Blue Thunder Pro amplifier, be sure to check out willistonaudio.com, where a full video of the amplifier's dyno will be released. Thank you for reading, and until next time, keep enjoying the music!


  • 1999 Car Audio and Electronics Directory
  • *Amazon - Novus Plastic Polish is an affiliate link

Tuesday, February 14, 2023

Michael Sears Electronics - Black History

Michael Sears


Michael Sears Electronics

In 1976, Michael Sears received an electronics kit which inspired his interest in electronics. 18 years later, he designed and introduced his own car amplifier, the Sears Electronics Model 2100HDP. Sears designed the amplifier using his own brain and a calculator, and it included a unique Automatic Power Control protection system. Sears opened his own electronics repair shop after serving in the army and working for cable and telephone companies. The Sears amplifier has received positive reviews, but he has only managed to finish and sell five units.

Prototype Michael Sears Electronics 2100HPA

Despite only selling a few units, the Sears Electronics Model 2100HDP has generated a lot of interest, with calls for information coming in from all over. Those who have used the amplifier have praised its power and sound quality, with one loyal supporter even winning first place in a competition with it.

Sears' interest in electronics began during his adolescence when he spent hundreds of hours working on various projects while his friends played sports and socialized. He later served in the army as an electrician and worked various tech jobs before opening his own electronics repair shop in his cousin's garage. It was during this time that he noticed that many car amplifiers had similar issues with power supply burnout and weak output.

Circuit Board of the 2100HDP

Although Sears didn't expect to do better than other companies at first, he saw an opportunity to develop a better design for car amplifiers. His use of a Casio calculator was key to the design process, allowing him to write custom programs that he couldn't do with computer-aided design (CAD) software. The resulting amplifier includes custom programs for wire resistance, amplifier power, and "maximum junction temperature," as well as the unique Automatic Power Control protection system.

While Sears has only managed to sell a few units of the Sears Electronics Model 2100HDP, he gained recognition in and around Elizabeth City, NC. He had loyal supporters, such as Kenny Proctor and Jesse Purkett, who enthusiastically spread the word about the power and sound quality of his amplifier.

Despite only producing and selling five units, Michael Sears had already generated a buzz in the audio industry, and many people were eagerly waiting to see what he would create next. Sears was not only skilled at designing audio equipment, but he also had a talent for marketing and generating interest in his products.

After the success of the 2100HDP, Sears continued to develop new audio products, including a line of high-end car audio amplifiers that received critical acclaim. However, he faced challenges in scaling up production and distribution, which limited the availability of his products and prevented him from reaching a wider audience. He designed several models for the company Dr. Crankenstein, including the DC3200. This amplifier had a retail price of $2799 and was said to produce nearly 4000 watts, an incredible feat in the early 90’s. 

Today, Michael Sears is recognized as a pioneer in the car audio industry, and his legacy lives on in the innovative designs and technologies that he created. Unfortunately, Michael Sears passed away in 1995 in an automobile accident. His story serves as an inspiration to aspiring engineers and entrepreneurs, demonstrating that with hard work and determination, it is possible to achieve success and make a lasting impact in any field.

Note: if you have a Michael Sears Electronics amplifier, no matter the condition, please contact me as I would love to share it with the car audio community along with Michael's story with help of his brother Steve.

Michael Sears and his 2100HDP Amplifier

Monday, August 8, 2022

Williston Audio EXTRAS - Old School Goodies!

Wow, it's been a minute since I've posted an update here. I wanted to let you all know I'm still making videos weekly on YouTube and recently added a 2nd channel for more content. My main channel, Williston Audio Labs will always be accessible via http://www.willistonaudio.com, but the secondary channel called Williston Audio EXTRAS will be available via http://retrocaraudio.com. This EXTRAs channel includes videos I think may have less interest than those on the main channel. This includes a lot of old school car audio equipment.

Recently I've released some videos of LA Sound, Xtant, MTX and more amplifiers you may want to check out if you haven't already. I'll link them below. Please remember to subscribe if you haven't already as I'm releasing weekly videos there as well!

Thanks as always for watching, sharing and engaging!

1998 Xtant 1001dx

1994 MTX Black Gold BGA2125

Again, more videos are available here: https://www.youtube.com/c/WillistonAudioEXTRAS/videos

Wednesday, June 19, 2019

Old School SPL Challenge?

With the recent $150 SPL challenge ending, HifiVega and I have been discussing ways to create old school challenges and his idea for the first one is....

SPL challenge using old school IASCA power class rules. Four Classes total:

(1) Zero - 50 watts

(2) 51 - 100 watts

(3) 101 - 250 watts

(4) 251 - 500 watts* (walled included)

*(includes other classes walled. In other words if you go walled, you will automatically be placed in 251-500 walled class, even if you have a 50 watt amp. Walled is defined as box is 12” or closer to headliner. 12” ruler must fit between the box and the headliner across the entire box to be excluded from walled class)

Classes based on rated 4 ohm stereo power of old school amplifier (must be year 2005 or older amp). Subs can be old or new, no limit on size or quantity. SPL measurements only as we can't have SQ judges checking out everyone's car. SPL measurements accepted by TermLab, SSA APM-2 and SPL Labs meters. No mics, sorry (I know that's more old school, but too many variables). No subs allowed forward of B-Pillar

We will provide list of car audio shops who will donate meter time or list their metering fee. There will be a Facebook group all are welcomed to join. We will also keep results on OldSchoolStereo.com, however it wil be much easier to keep up with the challenge on Facebook.

Meter must be placed on windshield. No restriction for location. Doors closed and windows sealed up. Challenge ends on October 21, 2019.

Now, I know people will complain about the US Amps VLX and Orion Concept amps, but this is just for fun, right? Will be cool to see what people can do with Orion 225 HCCA's and Punch 45's

Goals? Have fun, bring out OS equipment to use and show off. Prizes for winners.More details coming!

Examples of cheater amps? US Amps VLX Series (25, 50, 200, 400), Orion HCCA (225, 250, 2100), Concept 97-3, Lanzar 50C, Crossfire CFA15/30HC, HiFonics Ulysses/Isis, Rockford Power 50x2, PPI ProMos 25/50, ProArt 50/100, Phoenix Gold MPS2220/2240/2500, Soundstream Class A 3.0/6.0/10.0/10.2, Audio Art 50/100HC, Earthquake 40UHC, Planet Audio P225HC (20x2), Crunch 50SHC, Memphis HC50, MTX MTA225, MTA250, 225HO, MMATS D100HC (200W @4 ohms), and more!

Old School SPL Leaderboard

(updated 8/10/19)

0-50 Watts

1. 143.6db Matthew Starke Soundstream Ref 200s
2. 132.8db Jud Stansell RF Punch 45 25tolife

51-100 Watts

1. 143.8db Matthew Starke RF 200s
2. 139.1db Nick Winner US Amps 100

101-250 Watts

1. 150.00db Matthew Starke RF punch 150 25tolife
2. 144.7db Brad Newsome Hollywood RVH-1000m
2. 140.3db Shanon Arrowood Kicker ZR 360
3. 137.4db Brad Schulke Crutchfield 50x4
4. 133.9db Clint Faist Lanzar Optidrive 200

251-500 Watts *walled class*

1. 149.6db Mitchell Mbooma Bulmer MTX 81000d
2. 148.48db Matthew Starke US Amps 1000
3. 148.18db Ronnie Smith Apline MRV-1507
4. 146.2db Clint Faist Elemental Designs nine.1

Monday, April 23, 2018

OSS Swag Now Avaiable! T-Shirts and More

Finally!! Get your Old School Stereo "I am Old School" design T-shirts exclusively on the TeeSpring site here: http://teespring.com/oldschoolstereo

Depending on feedback, I may post new designs occasionally. The design show above is our most popular design, choose between 4 colors and several sizes. Each shirt purchase helps support OSS / Williston Audio Labs and allows us to continue offering unbiased reviews.

Also, just in time for summer, check out this Old School Stereo "OSS Parking Only" Beach Towel. The towel is 62" x 30" and shows the beautiful internals of the Audio Art 100HC amplifier. Get yours while they are available! https://teespring.com/stores/bigdwiz

Thanks as always for supporting OSS. Don't forget to subscribe to our YouTube.com/BigDWiz channel so you can keep up to date on our latest audio test!


Wednesday, February 14, 2018

BigDWiz Shout Out Series Episode 2

Here we have episode 2 of the BigDWiz Shout Out Series. Today we look at the following Channels:
Old School Car Audio
Ryan Blankenship

Please check out each of these channels and make sure you subscribe and tell them BigD sent ya!

Old School Car Audio is a relatively new channel by my mate Craig down in Australia. Although he just started a few months ago, the videos are superb quality and this channel deserves WAY more views and subscribers. See information below:
YouTube Channel:  https://goo.gl/Gx2AtH
Welcome To Old School Car Audio: https://youtu.be/srRAze-9jqw
Jeep JK Wrangler Project: https://youtu.be/kk_DaE6f4Vo

Datatech2000 is a channel displaying mostly car audio head units. Dan runs the channel and shows off everything from early 80's Pioneer head units, to highly desirable Nakamichi tape decks and early 90's Alpine CD tuners. Dan also repaired my Sony CDX-R77 that would not play CD's. Great technician as well!

YouTube channel: https://www.youtube.com/user/datatech2000
Alpine 7902 CD Tuner: https://youtu.be/QUrZLx9HFbQ
Nakamichi TD700: https://youtu.be/fdV90-L0Gl0
Vintage Pioneer KP 500: https://youtu.be/I4P6HlfpSa0
Contact Dan for repairs: dantheman209@gmail.com

Ryan Blankenship's channel focuses on car audio amplifier tests and what he calls "Budget Gem or Budget Bust". He unboxes the amps, then tests, then talks about the results.

Ryan's YouTube Channel: https://www.youtube.com/user/bigblank69
Precision Power Black Ice 7000: https://youtu.be/Q3bgecZvlAA
Rockville DB16: https://youtu.be/OAGjWcfFZqY

Barevids is a UK based channel displaying mostly videos about amplifier repairs. I find the videos fascinating and think you will enjoy them as well!

Barevids YouTube Channel: https://www.youtube.com/barevids
Banda Amplifier Repair: https://youtu.be/P5fGVMVgGtg
How Do Car Amplifiers Work? https://youtu.be/T507jHLQFnQ

Send me a few bucks if you want to support: https://paypal.me/BigDWiz

My Favorite Screwdriver Kit: http://amzn.to/2x0VzcE

Test Your Own Amps! SMD / D'Amore Engineering AMM-1:
Amazon - http://amzn.to/2u2EgKV
WCCarAudio - https://goo.gl/CVCgU3

Make sure you are subscribed to my channel so you'll receive notifications when I upload the next exciting video! Thanks for your support and remember to keep it Old School!

Support OSS - Williston Audio Labs and get extras!

Subscribe to my channel: http://www.youtube.com/BigDWiz
Visit My Website: http://www.oldschoolstereo.com
Follow me on Twitter: http://www.twitter.com/oldschoolstereo
See cool pics on Instagram: http://www.instagram.com/OldSchoolStereo

MUSIC BY: YouTube Artist free for use on YouTube video

Sunday, December 17, 2017

OSS and Williston Audio Video Updates!

It's been a while since I've posted here, so I thought I'd add updates to the Video page showing a huge list of my videos, hopefully more easily categorized than on YouTube. Notable updates include:

1999 Rockford Fosgate Power 1100a2 Amp Dyno Testhttps://youtu.be/zADEl30A8_o

1987 a/d/s PQ20 Review and Amp Dyno Testhttps://youtu.be/KrLNDorSHKk
1996 Cambridge Soundworks Model Twelve Transportable System https://youtu.be/_OIsKjCs-D4

Again, there are MANY more new videos listed in alphabetical order on the Video Section of this website, don't forget to check that page and keep it bookmarked.

Make sure you are subscribed to my channel so you'll receive notifications when I upload the next exciting video! Thanks for your support and remember to keep it Old School!

Support OSS and get extras!


Subscribe to my channel: http://www.youtube.com/BigDWiz

Follow me on Twitter: http://www.twitter.com/oldschoolstereo
See cool pics on Instagram: http://www.instagram.com/OldSchoolStereo

See Recent Old School Installs Compilation Volume 2 on YouTube

or embedded below:

Sunday, January 29, 2017

Rockford Fosgate Power 1000c Amp Dyno Test

The Power 1000c or Power 1000 MOSFET was Rockford Fosgate's top of the line amplifier offering from approx. 1990-1994. Earlier models of the 1000 were available in black or custom colors via the Perfect Interface division. The 1000c is one beautiful amplifier! It's retail cost was $2699 USD and was rated to deliver 150x4 at 4 ohms or 500x2 at 4 ohms. See previous videos where we've discussed this amplifier more in detail.

RF Power 1000 Terminator - https://youtu.be/Ro1rra0bmGI

Old School Monster Amps: https://youtu.be/aBHqYCYtfMc
RF Power 1000 repaired - https://youtu.be/IRe-STOe1B0
RF Power 1000 2 ohms dynamic - https://youtu.be/Jyc_ZXr1G9Q
RF Power 1000 MOSFET Playlist - https://www.youtube.com/playlist?list=PLu98-M_EowHMhBMvLp8u-G2ZpoCBZJP7b

Make sure you are subscribed to my channel so you'll receive notifications when I upload the next exciting video! Thanks for your support and remember to keep it Old School!

Support OSS and get extras!


Subscribe to my channel: http://www.youtube.com/BigDWiz

Follow me on Twitter: http://www.twitter.com/oldschoolstereo
See cool pics on Instagram: http://www.instagram.com/OldSchoolStereo

See Amp Dyno Test in 1080P on YouTube

or embedded below:

Tuesday, January 24, 2017

Updates at OldSchoolStereo - January 2017

Sorry guys, it's been a minute since I've updated the OSS website. I spend most of my "free time" editing videos and sharing cool pics on Instagram. OSS has grown quite a bit in the last year and we are now over 22,000 YouTube subscribers, 12,500 Instagram followers, and 5000 plus likes on Facebook.

You may have noticed I have also tested more new amplifiers. I feel this is important and I will include as much historical information on the company as possible. My BigDWiz YouTube channel will continue to show OSS content as well as other audio, video, photography and technology related videos. Consider the Old School Stereo component will be a "show" on the BigDWiz channel. We put a lot of time and effort into our videos and feel adding newer technology as well to the channel will help us grow, and also introduce people to the vintage gear.

Thank you as always for supporting OSS, see the updated video list in the Video Section of our website. I've posted a few of the more popular recent videos below. More coming soon! Make sure you are subscribed on the BigDWiz YouTube channel for updates when new videos are released.

Sunday, December 28, 2014

Linear Power 8002SW Amplifier Amplifier Dyno Test Old School AD-1

Early 90's Linear Power 8002SW 800W Mono Amplifier
The Linear Power 8002 was an 800 Watt single channel amplifier optimized for 8 and 4 ohm loads. It was available from 1991-1997 and sold at a MSRP of $1599. Unlike most of the mono amplifiers of today, this 8002 is capable of reproducing the entire 20Hz - 20kHz frequency range. 

We initially ran all of the tests using the 4 ohm power supply taps, which lowered rail voltage and increased current. Amp is less efficient in this mode and also produced less power. After a call with Linear Power, it was suggested I set the amp to the 8 ohm taps to run the 8 and 4 ohm Dyno tests. If you read the original Linear Power manual, they caution against running the amp in 8 ohm mode powering 4 ohm speakers. It is quite evident these amps are overbuilt and are more than capable of handling the additional load without breaking a sweat!

Linear Power 8002SW's Guts - TO-3 Transistors

Specifications according to the 1991 Car Stereo Review Directory (July/Aug 1991):

"1 channel. 800 W x 1. Features biwired output terminals for feedback loop, which keeps speaker wire DC resistance from reducing damping factor; defeatable subsonic filter; soft turn-on/off; fan cooling; metal shroud. FR 19-20,000 Hz. 17 x 3 x 9.5 in - $1,600" (CSR Jul/Aug 1991)

The Linear Power 8002 was also in a battle of "monster" amplifiers in the October 1991 Car Audio & Electronics magazine. Other challengers were the Rockford Fosgate Power 1000 Mosfet, Precision Power 2350DM, Orion GS500 and HiFonics Colossus VII...quite a group of large, powerful, Class AB amplifiers! Since the 8002SW is a mono amplifier, the tester used 2 of these amps in the comparison. It may or may not surprise you, but the Linear Power came out on top. Quite an impressive feat, considering the competition!

Watch the video and see the results obtained from this 20yr old car audio amplifier. Nothing short of spectacular!

Here are the results from my test with the SMD/D'Amore Engineering AD-1 Amp Dyno:

8 ohms mono8 ohms - Amp is rated at 800W at 12V
8 ohms - Certified 1% THD - 818W at 13.99V
8 ohms - Uncertified - 819W at 14.05V
8 ohms - Dynamic RMS - 1029W at 14.31V

4 ohms mono4 ohms - Amp is rated 800W at 12V
4 ohms - Certified 1% THD - 824W at 13.5V
4 ohms - Uncertified - 855W at 13.48V
4 ohms - Dynamic RMS - 1407W at 14.5V
4 ohms - Dynamic RMS - 1606W at 15.17V

All tests above were at 40Hz. As you can see by the results, this amp is well suited for subwoofers or mid-basses as it has a nice amount of dynamic headroom for those transient peaks. 

Watch the video in full 1080P HD Here >>

Or embedded below:

More Amp Dyno AD-1 tests coming!

Make sure you are subscribed to my channel so you'll receive notifications when I upload the next exciting video! Thanks for your support and remember to keep it Old School!

Subscribe to my channel: http://www.youtube.com/BigDWiz
Visit My Website: http://www.oldschoolstereo.com
Follow me on Twitter: http://www.twitter.com/oldschoolstereo
See us on Facebook: http://www.facebook.com/oldschoolstereo

Check out these other cool car audio channels: