Wednesday, May 31, 2023

Nakamichi NDST500A 12 Channel Digital Signal Processor 10 Channel Amplifier Designed for Hi-Res Audio

***Updated. See update towards the bottom of the review.***

Car audio has been around for several generations. But it didn’t really take off until Jim Fosgate invented the first car amplifier in the early 70’s. Back in the day (30-40 years ago), if you wanted the best car cassette deck or CD receiver, it was Nakamichi. They made the best of the best, in sound and build quality. After a hiatus, Nakamichi car audio is back in the US. But is it the high-quality products that gave them the reputation? Time will tell. Up for review today is a DSP with built-in amplifier, the Nakamichi NDST500A.  MSRP is a very fair $1,049.99.


Features and specs:

Dynamic Range (RCA Input):  ≥100dB

S/N (RCA Input):  ≥90dB

THD:  ≤0.05%

Frequency Response:  20Hz~40KHz

Input Impedance:  High Level Input:240Ω

Low level Output Impedance:  51Ω

Signal Input Range:  RCA:  7.5Vpp; High Level: 26Vpp

Signal Output Range:   RCA: 8Vpp;


Amplifier Power

PEAK: 4CH×50W+4CH×80W+2CH×160W, Bridging 1×300W

RMS: 4CH×25W+4CH×40W+2CH×80W


Power    DC9V-16V

REM Input:   High Level Input Signal:H1+/H1-or ACC control cable

REM Output:  +12V Start up Voltage Output

Standby Power:  ≤0.1W

Gross Weight:  Approx. 2.08kg

Product Dimension(L×H×W):  255×175×47mm



Input Type:  6(8) Channel high level, 2 Channel Low Level, External digital Bluetooth, Optical, coaxial

Output Type:  12 Channels low level, 4CH×50W+4CH×80W+2CH×160W, Bridging 1×300W

Output Gain:  Gain range:  Mute, -59.9dB~0.0dB

Output Signal EQ:  31 band Equalizer Engine,

1.Frequency Range: 20Hz~20KHz, 1Hz Accuracy

2.Q value (Slope): 0.404~28.85

3.Gain: -12.0dB~+12.0dB, 0.1dB Accuracy


Output Signal Crossover: Each output is equipped with multi-order high and low pass independent filters.

1.Filtering types: Link-Rill, Butter-W, Bessel

2.Filtering frequency division point:  20Hz~20kHz, Resolution 1Hz

3.Filter slope (Slope) setting: 6dB/Oct to 48dB/Oct and OFF

Output Phase and Time Alignment           

Each output channel can be adjusted for phase and delay, parameter range : phase: in-phase or reverse-phase(0°/180°);

Delay: 0.000 to 20.000 ms, 0 to 692 cm,0 to 273 inch.

Presets  Save 6 presets into the device.


The Nakamichi NDST500A came in a great looking color printed box, with photos and specs of the DSP/amp. Opening the box revealed a well-protected product, held in place by foam. Materials used in the construction was mostly metal, with some plastic. Quality of materials used as well as fit and finish was excellent.  Also included were the wiring harnesses, mounting screws, USB cable, and owner’s manuals.


I really like the design of the Nakamichi NDST500A. It’s an all-in-one design, with both a DSP as well as an amplifier. It’s designed as an all-in-one solution for upgrading your car stereo. No matter if it is totally stock, or an after-market system, the Nakamichi NDST500A will work with it. The one downside, while small, is that it only has two RCA inputs. What that means, is that if you have an aftermarket receiver, you will be limited with the RCA outputs if you want to use them.


The Nakamichi NDST500A is designed to get the best sound possible out of your car stereo system. It starts with the DSP and provides 12 channels of it. And that’s a lot! Each channel is for a single speaker. And for each channel you get crossovers, as well as gains, delays, and EQ’s. This means you have total control of each speaker.  You can set the frequencies that it’ll play, the EQ curve that it’ll play (boosts or dips of frequencies based on your personal preference), as well as the gain or output level that it’ll play. Not only does it work to get the best sound out of your speakers, it also protects your speakers. It does so by feeding each individual speaker only the frequencies that it can play, and at the levels that they can handle.


The next thing that the Nakamichi NDST500A does, is also power your speakers. It does this through the built in amplifier. The built-in amplifier is actually 10 channels. You get 25 watts x4, 40 watts x4, and 80 watts x2 RMS. One small downside it that only the 80 watts x2 channels are bridgeable to 150 watts x1 channel. And the DSP and amp work together.


What does all this mean? For most people, this may be the only DSP and amplifier that you need. Most people in their cars may have a 2-way component system in the front and maybe a 2-way component system in the rear. In that scenario, you would need 4 channels for the fronts, 4 channels for the rears and the last 2 channels of the amp can be bridged to 1 channel for a subwoofer.


But it has 12 channels of DSP, and 10 channels of amplifier power. Why have 2 more channels of DSP? My reference system is a perfect example. My fronts comprise of a tweeter, midrange, and midbass for each side. For the rears I have a tweeter and midrange for each side. And being a bass-head, I need a lot more power to my multiple subwoofers. For my set-up, six of the channels will go to the fronts, four of the channels will go to the rears, and the last two channels of DSP will go to the subs. So for my extensive system, the Nakamichi NDST500A provides all of DSP channels that I need. And for the built-in amplifier, the four channels of 25 watts will go to the four tweeters. The four channels of 40 watts will go to the four midranges. And the final two channels of 80 watts will go to the midbass drivers.


When you think about it, for most people what the Nakamichi NDST500A provides is sufficient. 12 channels of DSP, and 10 channels of amplification should be enough. And when you think about it, 25 watts for a tweeter is usually enough. 40 watts to a midrange is usually enough. And 80 watts to a midbass is also usually enough. And just in case the included amplifier power isn’t enough for you, Nakamichi still has you covered. With 12 channels of DSP, the Nakamichi NDST500A also has 12 RCA outputs. So you can use the 12 RCA outs to go to separate amps. The Nakamichi NDST500A is actually very versatile. It’s a great all-in-one DSP/amp that is all most people will need. But if overkill is not good enough for you, with the 12 channel outs it can be the brains of a really massive system.


In setting up and configuring the Nakamichi NDST500A for my system, the software proved to also be very versatile. There’s a lot to the software, but looking at it everything makes sense and was pretty intuitive. There are the icons for all twelve channels at the top of the page. Clicking on the channel activates it. On the left is an image of a car with images of each speaker and its location. That speaker that is active is also highlighted red. You select the high pass and low pass frequencies, slope, and type of filter. Slope options are 6 to 48 db. There’s also gain, delay, and 31 band EQ. And each band has not just a gain but also a Q, for the width of the slope.  All of these options including the 31 band EQ, are available and adjustable for each channel.


The software looks great, and like I said before, really robust. It helps to really dial in your car’s stereo system. You custom tailor the best sound for your car, and it’s acoustics. It’s very simple to use with your laptop. But there’s also a version of the software for your smartphone. And to test its sound quality, our reference system comprises of a Kenwood Excelon Reference Series receiver, German Maestro’s best M-Line speakers that are hand made in Germany, Alpine Type X speakers, and Image Dynamics subs.  They are excellent audiophile speakers to get every ounce of resolution and details from the music.  Now that it’s installed and configured, let’s see how it sounds.


Nat King Cole – LOVE:  vocals were silky smooth like honey, with excellent texture of the timbre.  Piano sounded very natural, and strings were also very smooth.  Trumpet was not just crisp and clean, but also extremely dynamic!  Trombone also had great tone and harmonics.  Not only was there an excellent level of resolution, I also heard a soundstage that was wide and deep, with excellent imaging.

Dire Straits – Money For Nothing:  vocals were again smooth like Swiss chocolate, with excellent resolution to reveal the great texture of the timbre.   Guitar was nice and raw.  Drums were very dynamic with great pitch definition of the midbass.  This is a song that as soon as you hear the first of the drums kick in… just begs to be blasted!  And the Nakamichi provided plenty of power to really play loud, and did so really cleanly!

Cat Stevens – Father & Son: the acoustic guitar was phenomenal! The resolution from the strings was excellent, so crisp and clean. You could even hear the decay of the strings after being plucked.  The vocals were also really smooth with excellent timbre.  And the soundstage was not only deep, the imaging was spot on, being able to hear slight variances as he changed slight direction on the mic.  The drums were nice and dynamic, and the cymbals crisp and clean.

I also listened to dozens of others of my favorite tracks.  And the results were the same.  Vocals were so silky smooth with tons of resolution to really reveal the subtle nuances of the texture of the timbre.  Drums were dynamic, cymbals were crisp and clean, and kick drums had excellent depth, impact, and authority.  Strings were smooth with sufficient resolution to reveal the bow across the strings. Brass was also so smooth with excellent harmonics. Piano sounded natural and also provided good dynamics and harmonics.  I was expecting good imaging and soundstage.  But I wasn’t expecting imaging as good as it was.  And I had not heard a soundstage this big in my system before.  Sure, I had heard tracks throw a wide and deep soundstage.  But there were also tracks where the soundstage seemed to come at me, jumping off of the front dash and come at me, like 3 inches in front of the dash.  That was a first for me!  It seemed as though no matter how good your speakers are, the Nakamichi NDST500A will not be the weak link in your system.   


I had high hopes for the Nakamichi NDST500A. Back in the day, they made some of the best products. Based on the Nakamichi NDST500A, their reputation appears to be intact. It’s a very solid well-made product. The DSP works great, the amplifier provides good power that is not only clean, but also transparent for the source material.  I was a little skeptical at first with the smallish amount of power that each channel was providing, when I first saw the specs.  But then when I really thought about it, the amount of power provided should have been sufficient.  And that proved to be the case.  There was enough power to not only provide very good resolution, but to also provide a great sound stage, imaging, and excellent dynamics!  It’s Nakamichi’s first product designed for and to receive Hi-Res Audio certification.  And the sound quality shows in its performance.


After the review was completed, Nakamichi sent us their AC2 remote for the Nakamichi NDST500A.  It's an excellent remote, and it does much more than a bass remote like most subwoofer amps provide.  But it could be even more.  Most remotes are just bass remotes, that can increase or decrease the amount of boost for the bass.  Some bass remotes also let you adjust the frequency of the boost, as well as the "Q" or width of the boost.  For the AC2 remote, not only does it adjust the volume of the bass, it allows you to adjust the volume off all channels of the Nakamichi NDST500A.  You just select the channel, and adjust the volume.  

It also allows you to switch between programmed presets.  So just as many audio products will have DSP presets to choose from like Jazz, Rock, Classical, etc, you can do a similat things with presets in the Nakamichi NDSTA500, and switch between those presets with the AC2 remote. What it does not do, is allow you to adjust the subwoofer boost frequency and adjust the Q of the frequency.  Hopefully that functionality can be added to a future version of the remote.  


Kudos to Nakamichi on staying true to their reputation. At least based on this product. Hopefully we’ll be able to continue to see how they perform with more of their products. I just would have liked to see RCA inputs for all channels.  The Nakamichi NDST500A is a great performing product that delivered in spades. And it’s well made to provide years of use. If you want to take your car stereo to the next level, to a fully active system, a product like the Nakamichi NDST500A is a necessity. And it deserves to be on your short list. Based on its design, features, quality, and performance, the Nakamichi NDST500A has earned our Editor’s Choice Award. For more info and complete specs, check out their website at  Reference gear used: Kenwood DNX997XR reference series receiver, Wavtech Link 500.1 sub amp, German Maestro M-Line 3-way component speakers, Alpine Type-X 2-way component speakers, Image Dynamic quad ID8 subwoofers.