Aphex, and the Aural Exciter


The Aphex company in general and their Aural Exciter (or on their new website, now just called just the EXCITER, HERE) are virtually unknown in the Home Stereo / Home Theater world. Very successful in the Broadcast / Recording Studio / Professional / Live Sound Venue / Club Installation markets for 40+ years, it can be safely said that essentially any of the music you hear on your radio or a CD or download from some website has at some point in its life passed through an Aphex device, (they make many other things) whether it be a superb microphone preamp or compressor, or limiter, or Aural Exciter or gate, or one of their exemplary guitar / bass foot pedals.

In the Los Angeles recording studios, the early units were rented (by the minute!) and it was considered a "secret" to getting a sound that was just a little more magic than the "other guy" could get, and by word of mouth, the studio use of their devices spread like underground wildfire in the 70's and 80's. The first "big" album to use the Aural Exciter was Fleetwood Mac, Rumors.

In the mid 80's, telephone talk shows were the up and coming rage in AM radio. I had the opportunity to set up a rather fancy station in Miami. Of course the station management and producers were always looking for some sort of "edge" to their sound, to make it "louder", "hotter", "better" and so on, (and we could hope more tasteful, but nah...) I brought in an Aural Exciter processor and hooked it up to the telephone audio feed, and the result was the incoming telephone line almost sounded better than the host's $1000 microphone! So we put a 2nd unit on the host's voice! The producers of that show and the radio station management were stunned at how their new-found clarity made their station "jump out" on the radio dial — it made AM sound like FM — and everyone was thrilled.

Here's a recent article with a nice history: www.musictech.net/2014/06/aphex-aural-exciter/


This same technology is available to be connected to any home theater or 2-channel stereo system, and it will amaze you. It is affordable and rather easy to use — it puts the FUN back into audio. Remember when you were a teenager and the latest song came out on the radio an you sat glued to the (probably not very good) speaker, enthralled with the sound and at the same time wishing it could sound even "better"? How it could have more bass, have cleaner and crisper highs, be louder, punchier, and so on... and, "wouldn't it be nice if..."

Here's another example. Let's say you have a pretty nice 2-channel "stereo", with pristine components and you think you are hearing everything that's "there". Well maybe...especially if you still have a high-end analog turntable/phono setup. But because of the limitations of the CD technology, if you play CD's you are missing what can only be described as the "air" in the recordings. But you don't KNOW that, because you have never heard it any differently! You have nothing to compare that's any better!

Please understand: the Aphex is NOT an equalizer. (besides, equalizers don't make things 'equal' — but that is the topic for a large book, not this article...) It is a dynamic, realtime processor, with separate sections that operate in the low frequency area of the spectrum (the "Big Bottom" part) and a section that operates in the high frequency part of the spectrum (the "Aural Exciter" part). You will, for example, be able to make cardboard drums from mediocre rock n roll recordings sound much more alive and punchy; you will be able to hear "way into" the mix as you have never heard before; vocals will have a more intimate presence, and you may even hear subtle things you had NO IDEA were there. Serious classical students comment that for the first time they truly hear the "wood" of the cello and violins as if it were right in front of them, and they also always ask why this audio information "gets lost" in the recording process...

I used to have a model of the Aphex 204 set up in my high end store. Every time (without exception) that people came in and brought a CD with them I would say "watch my fingers and listen" as I pushed in the buttons on the 204, and when they heard the difference their jaws would drop.

I had arranged for a unit to be sent to the nice people at Secrets of Home Theater and High Fidelity. Colin Miller has written an amazing and complex review which you may read HERE.

I'll cut to the chase. You can make an astonishing difference in your system, especially when playing older CD's and rock n roll and it will add a magic quality of air and ambience to dull classical recordings that will stun you. Part of the enjoyment in this device is that IT AFFORDABLY RECONNECTS YOU TO THE PROCESS OF ENJOYING THE MUSIC. You now have:

a)  various knobs to turn,
b)  they actually do something you can hear!

Yes, you may leave the settings alone at some nice position, but being involved with music YOU THINK YOU KNOW and hearing it in what seems like a totally fresh and exciting new way is a large part of the magic.


With a 2-channel system you can put one unit (2 channels) essentially anywhere in the chain: either in the tape loop, between the "preamp out" and "power amp line in", or even in the analog path at the line outs of the CD player. If your preamp has a tape loop function then that is the easiest place. Since the unit has both unbalanced AND balanced connections it can be wired to anything.

Fig 1. Aphex 204 placed at CD player LINE OUTS
Fig 2. Aphex 204 placed in the "TAPE LOOP"
Fig 3. Aphex 204 placed between PREAMP OUT and POWER AMP INPUTS
In the instance of a Home Theater setup, where you have a typical Surround Sound Receiver (i.e. a Denon, Marantz, Pioneer, Anthem, Outlaw, Yamaha, B&K, NAD, etc etc) you can simply connect ONE 2-channel 204 unit to the tape loop and you're in business. This gives you control over the Left and Right front channels, but you MAY want to have control over ALL the channels in which case you would need 3 (2-channel) units for the 6 separate pre-bass-managed signals: L, C, R, Ls, Rs, and LFE.
Fig 4. Aphex 204's placed at the ANALOG OUTS of DVD player

Since most HT receivers don't have a PRE OUT to AMP IN insert point, placing the Aphex 204 at the analog outs of the DVD player becomes the best solution. See Fig.4. This gives you full range control of each signal, BEFORE it is bass managed, so it becomes very easy to visualize and comprehend what's happening. When you turn the knobs on the Center channel (for example) which would typically be the soloist's voice, or perhaps a solo saxophone, etc. it becomes immediately and easily apparent what you are controlling.

If you have the luxury of having a separate PREAMP/CONTROLLER and POWER AMPS, then you can connect the Aphex 204's AFTER the bass management section, in which case your channels would be called: L, C, R, Ls, Rs, and SUBWOOFER. See Fig. 5 below.

In this instance, the "BIG BOTTOM" low frequency controlling part of the 204 (for the 5 'main' channels) would have their effect only within the band that was not bass managed, so if your crossover frequency was set to 80 Hz their effect would be between 80 and, say, 200 hz or so, which you would then hear in the SATELLITES, while most of the low frequency adjustment effect would be coming from the single channel of the 204 in series with the SUBWOOFER signal, which after bass management is composed of all the low frequency information (below the crossover frequency) from all 5 'real' channels plus the LFE effects channel, (if any); this is summed together and "becomes" the SUBWOOFER channel.

Fig 5. Aphex 204's for surround setup placed after ANALOG OUTS of PREAMP
Here is what the Aphex 204 looks like. If you remove the rack ears the unit will then sit very nicely on top of any other audio equipment. Note this is the original US version. The NEWER versions, very sadly, do NOT have removable rack ears.
The main Aphex website is here: www.aphex.com. The actual Model 204 page is here: www.aphex.com/products/exciter/  The user manual is HERE 1.3mb

The 204 can be connected with any combination of balanced or UNbalanced wires. if you want to connect it to the typical unbalanced RCA connectors on your stereo you will also need 4 x RCA—RCA cables (2 ins and 2 outs...) and 4 x RCA female to PHONE PLUG adapters, which look like this:

Fig 7.  RCA female to 1/4" male PHONE PLUG adapter
You can also buy from Soundoctor a specially made up cable set which is made of one Mogami umbilical cord (any length you choose) with 4 connectors on each end. Contact me for more info.

The MSRP of the 204 is ONLY $399.  You can buy it from various Professional Audio Dealerships and various Music Stores, but this product is UNKNOWN in the "Hi-Fi" "Stereo" and "Home Theater" stores. If you ask about this in a typical Hi Fi store you will get a blank stare.

This magic box puts the fun and excitement back into audio and your listening enjoyment for a very modest fee, especially compared to what you have probably already spent on equipment and speakers, to say nothing of exotic cables and other goodies. NO ONE I have ever shown one of these units to ever wants to put it down or be without it again!

Even recordings that you THINK are pristine and superb can still benefit by "opening them up" with a little air and intimacy. Older jazz transfers to CD's from early non-noise-reduced tapes (think Miles Davis) will absolutely amaze you as to their difference.

For home theater applications you can almost "dial in" the realism of the helicopters flying overhead, and the low frequency ("Big Bottom") section of the Aphex 204 will help even a modest subwoofer deliver fuller, cleaner, punchier, more dramatic (and psychoacoustically 'cleaner' ) bass. You simply can't go wrong with the "bang for the buck" factor.

There is no plug-in for experience...
SOUNDOCTOR                  BARRY OBER              EMAIL: barry@soundoctor.com