Humvee DIY Upgrade – Robust $100 HMMWV Intercom
Talk to me, Goose!
It only takes one short ride in a HMMWV to realize that you really can’t carry on a conversation with passengers at anything over about 20 mph without screaming at each other. And even then, it can be challenging. The obvious solution is to install an intercom. This is what the US military did and is the reason you always see soldiers wearing headsets in their Humvees. The demilitarization process requires that military intercoms are removed prior to HMMWVs being retired into civilian ownership.
Intercoms: Not just for HMMWVs
Ever notice that race cars have radios? So do many off-road vehicles like Jeeps and Land Rovers. If the vehicle is loud and talking to passengers over the noise is difficult, then adding an intercom might be a good solution. The recommended intercom setup below should work for any military vehicle, 4×4 or hot rod.
Try to be civil
So, what is a civilian HMMWV owner to do? For one, we just coated the interior of the Battlewagon with LizardSkin Sound Control and Ceramic Insulation. That should absorb some of the road and engine noise. However, insulation can only do so much. There is still a lot of wind noise and engine noise to try to talk over, and a lot of distance between the seats. Adding an intercom to your Humvee will make conversations easier… and they look cool!
HMMWV Intercom Options
To make this project more interesting I set a $100 budget for a complete intercom system to connect all four passengers in the noisy Battlewagon together for easier communication. I can be sadistic like that sometimes.
Do you think that is possible?
First thing I did when I started looking for an intercom for the Project Humvee Battlewagon was check with Damage Control Customs. They could set us up with a complete US military VIC-1 intercom system. However, there was no way a military intercom system would come anywhere close to fitting in the $100 budget. And as I researched military vehicle intercom systems I realized that the series of control boxes and heavy duty wiring hooking them together tend to be big and bulky, taking up more interior space in the vehicle than I wanted. Military intercoms are very durable and functional, but a bit of overkill for my needs.
Before you dismiss the VIC-1 intercom system consider your goals. If you want your HMMWV to look like it did when it was in military service, then a real military intercom is your only option. I don’t doubt that many military vehicle collectors and restoration experts will cringe at the recommendation below..and that is OK.
I am still surprised that I didn’t find a workable, plug and play intercom solution using readily available USB headsets, like you would plug into a computer. Maybe my Google-Fu is weak. I thought about using of a mini computer like a Raspberry Pi with a USB hub and 4 headsets. However, over-the-ear headsets are required in order to block out some, but not all, of the ambient noise in the Humvee. I wasn’t successful looking for four USB headsets robust enough to survive in the Battlewagon AND a Raspberry Pi all for $100 or less. Add to this the idea that I haven’t done any computer programming in over a decade and I my once-suspect Linux skills have gotten obscenely rusty… and I really don’t need another computer to maintain. This once promising potential solution turned out to be a non-starter. I don’t doubt that someone smarter than me could make it work, and work well. Leave a comment if you do this.
As I searched online I found a variety of Motorcycle intercoms available. On Amazon I found options ranging a simple wired intercom for less than $15 all the way up to $1,000+ racing intercom systems. However, I had no luck finding any motorcycle intercoms in my $100 budget range on Amazon that I thought would work (most are designed to be installed in a motorcycle helmet, not worn independently) AND had decent reviews. Most were motorcycle intercoms were wireless as well, which meant batteries to charge and maintain, inevitable connection/pairing issues, etc. I really want a reliable, plug & play intercom system, so wireless was off the table.
We even tried a pair of UV-82 radios with VOX headsets, but found that the VOX circuit couldn’t handle the high noise environment in the HMMWV. In short, it was more frustrating than helpful. We love the radios for other things… they just didn’t work as an intercom.
Bluetooth Android Intercom app:
Heck, we even tried the free “Intercom” app on a set of android phones that were paired via bluetooth and with cell phone headsets plugged in. As great as that idea seemed, it proved to be unworkable because of a sometimes unstable connection, awkward/annoying delay and poor volume.
I thought that a general aviation (GA) intercom system would be a great option in terms of size, reliability and function. But if I learned one thing during my years of piloting aircraft, it was that EVERYTHING aviation related costs WAY more than it should. While an aviation intercom would likely provide just the elegant, streamlined and functional solution I was looking for, there were some issues:
- Power: HMMWVs have 24V DC power. To my surprise, most aviation intercoms list a range like 11-34V DC as acceptable input voltages. AND most portable intercoms also have battery power options.
- Wiring hassles: I had only ever used panel mounted, hard wired aircraft intercoms. Smaller than the bulky, complex military intercom systems, panel mounted aviation intercoms would still be more hassle than I wanted to undertake. Some research revealed a variety of self contained, portable intercom options.
- Intercom cost: I assumed that aviation intercoms would be too expensive… and most were. However, I noticed that every now and then a portable aviation intercom seemed to slip through the cracks on eBay and sell cheap. It took some time, but I got an expandable Signtronics 2-place (two headsets can be plugged in) intercom for less than $20 shipped. I pulled my David Clark GA headset and old US Air Force David Clark headset (with a GA adapter I bought years ago) from my flight bag and was thrilled to find that the Sigtronics intercom worked PERFECTLY in the HMMWV. With that proof of concept test passed and knowing we were about to convert the Battlewagon from 2-man to 4 man configuration, I spent a couple of weeks watching auctions until I found a 4-place SoftComm portable intercom for about $60 shipped.
- Headset cost: I remembered looking for an aircraft headset for Mrs. Gear Report years ago and being shocked that even a “starter” headset was at least $75. There was no way I would find enough headsets for the newly converted 4-man Battlewagon and and stay within budget… right? WRONG! It took some time, but I actually found a lot of 9 Telex Aviation headsets that I snagged for $60. Four of the headsets have microphones, five are just headphones with no microphones. I’ll sell the headphones and keep the four mic-equipped headsets, which should put me under my $100 target for this project. That will also let me put my pricey David Clark headsets back in my flight bag where I don’t have to worry about them walking away.
- Microphone performance: The ultra noisy confines of a HMMWV are not suitable to most microphones. Fortunately, GA aircraft cockpits are similarly noisy. GA headset mics are tuned to pick up human speech at VERY close distances (with the mic just barely almost touching your lips). I had initially thought about using a Raspberry Pi computer with USB headsets. However, the mics on consumer grade computer headsets are way too sensitive to background and surrounding noises and wouldn’t stand a chance in a Humvee.
- VOX performance: For an intercom to work well it needs to have a quick VOX circuit that won’t clip the beginning of any speech. VOX is the voice activated transmit function that lets you talk to other people who are plugged into the intercom without pushing a “talk” button.
In spite of my early expectation that a motorcycle intercom would solve my noisy HMMWV problem, it turned out that a mix of patience and used airplane communications gear is what worked best. It is really nice to not have to yell back and forth with passengers now.
Were we within our $100 budget?
The 2 person intercom came in WELL under the $100 budget since I got a SMOKIN’ deal on the the intercom and already had a pair of headsets.
The 4 person intercom was $62 and the lot of 9 headsets (4 useable in the intercom setup) was $60. So we were over budget by $20. However, we also got 5 sets of earphones (headsets without the microphone) that can be sold or tossed in my conversion van for the kids to use with the entertainment system.
Before you buy…
Aviation intercoms require compatible headsets. If you get a “General Aviation” intercom, then you will need to get headsets that are made for “General Aviation”. GA headsets have two of the old-school large plugs (one for Mic, the other for the headset itself). Be aware that helicopters and military aircraft use a single plug that does not plug directly into a GA intercom. You can get aviation headset adapters to change the impedance and plug type, but they will be an additional cost and tend to reduce the volume a bit.
Where to get Humvee parts:
- Probably my “go to” for real military parts is HMMWV parts on ebay
- You can get HMMWV books on Amazon
- Actually, you can get a LOT of upgrade parts on Amazon. We have made it easy by adding a HMMWV section the Gear Report Amazon store and add parts to it as we find them.
- Southern Metals Recycling… if you happen to be close to Wilmington, NC. They scrap HMMWVs for the government and can sell some parts.
More HMMWV articles can be found under the Humvee category menu above or by clicking HERE. You might also like the HMMWV section of our Amazon store where we have listed lots of replacement and upgrade parts for Humvees. We have also found a lot of HMMWV parts on eBay (link).
Please leave a comment if you have suggestions on other HMMWV upgrades should consider, or you have done upgrades that we can share on Gear Report.
The Project Humvee Battlewagon
Gear Report acquired a real HMMWV (High Mobility Multi Wheeled Vehicle) from the US Army for use as our official field and shooting range vehicle. We have already posted about some of our upgrade projects (Project Humvee Battlewagon article links) and have a lot of really cool projects on the way. Consider subscribing so you don’t miss any of the cool reviews as we post them.
Here is our Project Intro (link) and our list of HMMWV upgrade projects.