The KEYLOC comes in a small cardboard box – not a blister pack – so it needs to be in the stockroom, it can’t hang on a hook. In the box we found a wiring harness, the device itself in a plastic bag, a quick reference guide, and a few odds and ends.

OK, I said it does some cool things. What, exactly?

The first cool thing the KEYLOC can do for you is detect what frequencies are available on the speaker wires you have found. Kicker calls this Passive Frequency Detection, and it’s basically a three-band RTA – bass, mid, and treble. This is good for installers who don’t have RTAs, so they can make sure they aren’t about to try to get subwoofer signal off of midrange speaker leads, for example. (It’s better to have an RTA, of course!) The LEDs on the top of the unit are used for this purpose:

I tested this function and it works as advertised.

Another cool thing is that, unlike many Line Output Converters, the KEYLOC can handle 40V signals, making it a great choice for use with high-voltage subwoofer signals found in many premium systems.

The next cool thing it can do for you is undo OEM Equalization – even if the signal isn’t full-range. This is very useful, and not all correcting processes will do this (some hang up without a full-range signal and don’t give you anything useful). This is especially useful when adding a subwoofer. Many OEM subwoofers are undersized, and so the signal sent to them has very-low-frequency content attenuated.  Often, a higher frequency, say 60 Hz, is boosted in an attempt to hide the missing low bass. In OEM systems without a subwoofer, that low bass is often attenuated to keep the factory speakers from ripping themselves apart. The KEYLOC can deliver a signal either flat all the way across the band, or much closer to that than you started with, so you can get better sound from a subwoofer add or a full-range system.

The last cool thing it can do is optionally defeat OEM all-pass filters present in the signal. If you don’t know what those are, basically it’s a technique OEMs often use instead of delay, which works in a limited fashion for both front seats by manipulating phase at certain notes.  I said “can” because that function of the KEYLOC is selectable. Why? Well, in most cases where you’re using a KEYLOC, you probably aren’t using any additional DSP processing downstream, so you probably want to keep those OEM all-pass filters working for you. They’re there for a reason, and while we may not think it works as well as our high-end systems do with delay applied, it works a lot better than doing nothing to correct for car’s off-center listening positions.  If you’re using a KEYLOC in front of a tuning DSP, such as a Kicker IQ Series DSP amplifier, then you may want those all-pass filters corrected so you can then use delay afterwards (we can’t effectively use delay on channels not in phase with each other at all frequencies).

(No, I didn’t forget that it can also undo OEM delay and align the two channels in time – I just don’t think it’s all that useful. OEM delay is pretty rare.)

It should be noted that – like other, more costly DSPs which automatically address all-pass filters – it isn’t intended to correct them all. When multiple all-pass filters are used too close together – I took this as code for “the way Bose does it”, but that’s my interpretation – the KEYLOC won’t succeed at defeating all of them. The problem is too complex. I find that to be reasonable, and that should be taken into account when using this device. Simple Phase EQ in Toyota, Subaru, and Hyundai OEM head units – that’s meant to be fine. Complex Phase EQ in a Bose system? Well, I haven’t tested it in a Bose system, but based on the guidance I’ve been given, I wouldn’t bet on it.

Then I used the QR code, opened the manual in a browser, and read that manual. That manual explained to me I needed to download three files from the Kicker website. I went to the website, found them, and clicked “download”. Well, one of the files I selected was a 22-minute WAV file, and that was going to take approximately 9 years to download – so it kept failing. I went back to Kicker’s site and selected the .mp3 version of the file rather than the .wav version of the file. That downloaded instantly.

There was little guidance on why I might select one or the other, or what the effects might be for one or the other. I’d recommend this be explained somewhere (I was later  assured that in their testing, no one could hear the difference, and that’s encouraging). It turns out that there are other test tone files you also need to install this device successfully, and those weren’t on that list of three. You will also need various sine wave tracks and full-range pink noise. I recommended that something like this be added to the front of the manual:

This is important for you to know beforehand! Technicians in our industry – especially in some of the high-volume install bays – are used to taking the product out of the box, ready to go. The KEYLOC is NOT ready to go UNLESS you have the needed test tones on a USB stick or CD (and it’s really helpful if you have them in the proper sequence).

OK, once I got that handled, I proceeded to connect it to a head unit and calibrate it. Or, try to. Turned out I still had problems. Sometimes the instructions didn’t match up to what the LEDs on the unit were doing.

Fortunately, I know Joe Hobart in Kicker engineering well enough to text him on weekends, and he recognized the issue – when I used the QR code, I had downloaded a pre-release version of the product manual. He emailed me the latest version. (It’s hard to tell them apart, because Kicker oddly doesn’t put revision identifiers or dates on their documentation, which is decidedly not “best practice” in documentation creation). The QR code should now take you to the current version of the manual. However, you can’t check, because the updated version of the manual still lacked any date or revision number. You’re killing me, Smalls!

The instructions tell me to test the head unit’s output to make sure it isn’t clipping, and set the volume below the clipping point – or, to set it at 75%. So, trying to do what many technicians would do, I set it at 75% – as it said in the manual… And I proceeded to fail on every calibration I did!

Turns out the head unit I was using clipped below 75%. Even checking the signal at 1kHz with an o-scope – what many installers do to test signal voltage – didn’t help, because it was clipping in the bass. Due to the heavy EQ in the bass, it still gave me a clipped signal in the bass even when 1kHz was fine. That’s why I always recommend that you use an RTA to test the signal before you decide on which sine wave track to use to test. Well, the KEY LOC isn’t intended to require an RTA first, so the installer won’t necessarily know that. You could turn up the volume slowly during the Passive Frequency Detection process and watch which LED comes on first. If it’s bass, then use a 40 Hz tone as well.

So I needed to use test tones and an o-scope to ensure I wasn’t getting into clipping. I know how to do that, but many techs don’t, and the manual didn’t make it clear how important this would be, or how to do it. For that reason, I recommend the manual online also tell you how. I actually decided to test my head units at 50, 160, 400, 1k, and 8k, since those are the sine tracks on the Audiofrog Test CD. The GainMatch track from the Kicker test tones also sweeps sine waves from lows to highs for this purpose.

I first tested with an aftermarket head unit with the bass, mid, and treble tone controls randomly bumped and dipped to create a goofy response. Well, that turned out to be the one with problems with clipping in the bass. Fortunately, I got ahold of another OEM head unit, so I am throwing out the results with the aftermarket head and only reporting the results with the outputs of these two OEM heads, and then an OEM subwoofer channel emulation – an aftermarket head with a DSP amplifier downstream, adjusted with crossovers and EQ.

Head Unit #1 – 2010 Toyota FJ Cruiser head unit, non-JBL (same radio as the Tacoma of that period, but possibly different EQ)

First, the clipping tests.

Now, because I’ve done this a few times, I set the balance and fader of the OEM head unit to center before I performed the calibration. That should be in the manual, though.

Head Unit #2 – 2018 Toyota Tacoma non-JBL

Here’s the left and right channel before correction, and the two summed together (showing the area the two channels are 180 degrees out of phase, due to the Phase EQ). The left and right have different EQ applied, so I am showing both of them.

Here are the clipping results:

Here’s the corrected response I got the first few times I tried it, and the corrected summed response:

Now, that’s a solid improvement! If you have a subwoofer, it’s hard to say that the uncorrected signal (probably intended for a 6.5” or maybe an 8” sub) wouldn’t sound better on a high-performance 8”, 10”, or 12” subwoofer from the aftermarket.

Just like every other automatic-adjusting device I’ve ever used, I wouldn’t use this one without testing its output after its calibration step. If the output isn’t what you want, I would turn the volume down a couple clicks and try again. Otherwise, you run the risk of having used an advanced DSP correction device, and getting no correction applied to the signal.

I think it’s pretty obvious, based on the Passive Frequency Detection feature, that Kicker wants this device to be useful to installers who don’t have an RTA. Well, in the words of Denis Leary: I wanted to play center field for the Red Sox – life sucks, get a helmet. Successful OEM Integration requires tools.

Now, I have written several dozen manuals for various kinds of products – audio, security, video, even service manuals for FAA-certified in-flight multi-zone entertainment systems –  and I know it’s harder than it looks. I’ve also done years of tech support, and I’ve taken lots of tech calls which could have been avoided if someone had done a better job on the documentation. I found the KEYLOC to have incomplete and misleading documentation – that applies to the quick start guide and both installation guides I received – and that may make it difficult for the installer to get the results it’s capable of delivering. On top of that, as a document, I found the quick release guide to be impossible for anyone over 35 to see, and I found the text layout, line spacing, and illustrations included in the online manual – well, that just looked like a lousy job. The manual is part of the product, just like the hardware. Now, the day I finished this review, I saw that Kicker updated the online manual to some degree, and had followed some of the recommendations I had made, but it still has significant opportunity for improvement. I hope that Kicker continues to update the manual to a level that the product hardware merits – I like the product hardware, and I would definitely use it in the field.

Why did I call it a “ridiculously low price”? Because many shops are now $100 an hour or more for installation labor. In my opinion, this device requires use of an RTA to ensure that the calibration has been successful – otherwise, you run the risk of going through all that work and getting a signal that’s not much better than you started with! The complete installation is likely to take 60 minutes or more (setup alone can take 20 minutes in some rare cases, based on how long the FullTest track is), and that’s not counting any test-track downloading or CD-burning required.  All that means that installation time may cost as much as the device (and that can make for a harder sale)!

At that price, salespeople and technicians may underestimate what it takes to install this device. It’s not an LOC from an installation point of view.

Also, understanding when a device like this might be needed and knowing how to explain the benefits might be worth more than the gross profit dollars available at $130 retail.

Charge 20 minutes’ worth of install labor for an hour job, and then give the installer a confusing and incorrect set of instructions – and a product that’s not ready to install out of the box? Whatever that’s a recipe for, it’s probably not tacos. If you’re going to carry this really cool piece of gear, you need to have the files downloaded and ready, and you need to understand how it works.

This shouldn’t be thought of as an expensive LOC – it should be thought of as a low-cost EQ-correcting DSP, with an LOC built in!

I would use this with add-a-sub installs as an upgrade – especially with clients asking to move their sub and amp from one car to another. I would also use it in many basic amp-and-speaker upgrades – but probably not at list price. I’d bill for physical installation and then for setup as two tasks.

Delivers solid functionality that nothing else close to this price can deliver. Requires preparation before install, and more time than other LOCs, but the results are worth it.

• Add-a-sub systems – handles high voltage, extends low-end response, flattens OEM “one-note” bass boost
• Adding amplifiers to full-range signals out of OEM head units –  undoes the OEM EQ automatically, especially when there aren’t all-pass filters to deal with
• Adding amplifiers or DSP to partial-range signals out of an OEM amplifier – undoes the EQ, shifts crossover points farther into the stop band