Review D800.4 – Four Channel D Block Series A/B Amplifier

Aesthetics As much as all of us try and say that looks don’t play a part in product selection, for 99% of the market, it does.  I myself do care a look about the aesthetic design of the products I purchase, as I have a great appreciation for carefully thought out design.  In my opinion, it often costs the same to produce a bad looking product, as it would have to produce a well thought out good looking one.

In this area, the Massive Audio D800.4 does not disappoint.

This is one of the smallest amps I have used.  Massive Audio is going to have to change their name, as the amp is anything BUT massive.  It is freakishly small, competing directly with JL’s new XD and HD line.  It is a bit taller than the XD’s, but will easily fit into many of the same areas.  If I was an installer, I’d definitely be thankful for the footprint of the amp, as it opens up a ton of install location possibilities.  Spare tire wells, underneath seats, small cubbies, passenger foot wells, no location is safe from this amp.

Other than the awesome size, I love it for its simplicity in design.  It does not have any fancy flashing lights, skulls, airbrushing, etc.  The D800.4 has nothing but clean and smooth lines.  Upon powering the amp up, the Massive Audio logo in the center gently glows to let you know that it is operational.  Nothing too bright, nothing flashing, it just simply glows to let you know everything is okay.

Massive Audio is very confident in the efficiency of their digital design, and have excluded any fancy heat sinks and have opted to have a nice, clean chassis.  At any point during testing, cooling was not an issue.

Design/Fit + Finish From the moment I picked up the amp, it instilled a good deal of confidence in the overall manufacturing quality.  It is very heavy and dense, as Massive has packed a ton of components into a very small area.  I am not sure if the aluminum is extruded or billet machined, but it has a nice brushed finish to it.  The edges are clean and sharp and the amp arrived to me blemish free.  Nothing feels cheap on the amp whatsoever.

The gain/crossover pots are all of good quality, as were the speaker/power terminals.  I really enjoyed the detented pots, as they give a better tactile experience when making adjustments.  There was no slop around any of the connectors.  They seemed to be tied down to the chassis and board very securely.

On the surface of the amp there are several beefy hex head screws.  These add to the overall industrial look of the amp, as well as serving as cosmetic covers for the mounting holes.  Simply unscrew the corner hex head screws with the included allen wrench.  This will expose the 4 mounting points of the amp.  Mount the amp, using the screws or bolts of your choice, then screw the hex screws back on.  Voila, seamless installation.  No need to mess with amplifier feet or bottom mounting screws.  This is a very elegant solution similar to what JL provides with their top of the line HD amplifier.  I will also note that there are included wood screws for mounting purposes with the amplifier box.

With many amps moving their connectors to a single side of the amplifier, I was a bit disappointed to see that this amp was still in the traditional power/speakers on one side, and RCA/gains on the other.  Since the overall size of this amp is so small, I won’t count this as a huge con, but it would be nice in the future to see Massive moving towards a single-side approach for all connections.  This would open up even more possible install locations to everyone and provide JL even more competition in the small footprint/high power amp marketplace.

Features All amp manufactures boast a plethora of features, ranging from flux capacitors to lithium ion fission generators.  Many of these features are impossible to test/understand to the normal end user.  I’ll run through some of the features listed by Massive for their D800.4, focusing on the ones that I can tangibly identify and experience.

Filters – These are listed at 18db slope.  The frequency response of both HPF and LPF is 50-750hz.  The filters are able to be fully defeated by sliding the switch to “FULL”.

While I would love to see a x1/x10 multiplier of the internal crossover, allowing for a more flexible crossover, there aren’t many amps that include such a feature.  The only ones that I’ve tested lately that have such flexibility have been the Zuki Eleets, and the Zed Audio Leviathan.  The frequency response of 50-750hz is a bit limiting for the amp.  The only scenario I see this crossover being useful is to push 4 sets of components, or 2 sets of components plus a small sub.  Most users will not be using 4 sets of components, or trust “only” 240 bridged watts to push their sub, so these scenarios are a bit far-fetched.  I feel that anyone running an active setup will use the internal crossover in “full” position.

As for the choice of an 18db slope, I tend to prefer 12db slopes, as I personally feel that they allow for better integration between drivers.  Some prefer 24db slopes since they like to run their drivers close to their useable frequencies and need the steep drop-off.  Massive’s choice of an 18db slope is a smart one, as it effectively provides the best of both worlds, and does provide good phase response, so the user doesn’t have to worry about connecting speakers in/out of phase.  I tested the functionality of the internal crossovers using an RTA on my test bench, and am happy to say that they perform the way they are advertised.

High Power Output This amp is listed at 120×4 at 4 ohms.  It has a good power supply which allows it to also make 240×4 at 2 ohms as well.  I tested this amp pushing several power hungry woofers.  I was able to audition the amplifier with Seas’ ER18RNX (8 ohms), ID OEM V1s (4 ohms), and Exodus Audio’s Anarchy midwoofers (8 ohms).  I am happy to say that the amp delivered as advertised.  It was able to push all of these woofers to very high effect, without displaying any signs of distortion or loss of control at high volumes.  That being said, power ratings of amplifiers can most often be taken with a grain of salt, as some amps are rated rather optimistically, and others conservatively (Zuki @ 5 watts anyone?).  I feel that a challenging test of power hungry woofers is the best indication of just how good an amp’s power rating is in the real world, and The Massive D800.4 passed with flying colors.

Frequency Response We are definitely out of the dark ages of class D audio, and full range frequency response is completely possible.  This amp is rated for 15hz – 25000hz.  This was verified with an RTA.  In the real world, I did not notice any “darkness” that can be present with a poor top end frequency response.  Things where shimmery where they should be shimmery, and harsh recordings hurt my ears like usual.  I could not hear any difference in the frequency response of this amplifier against any of my A/B car audio experiences.

Noise Rejection Circuit This may sound pretty gimmicky, and if you had asked me about this a couple of years ago, I probably would have agreed.  That is until I recently ran into an install where I used a very high quality amplifier that had garnered a lot of praise from all comers.  It sounded great, but I could NOT get rid of electrical/alt noise no matter what I did.  I finally gave up after checking all of the common answers like grounding points, RCA runs, etc, and simply swapped the amp out for a JL HD.  This totally eliminated the noise.  I changed absolutely nothing else.  I was absolutely mystified and I bugged JL about the reason behind this.
Luckily, I still had access to the “problem” car, and installed the Massive Audio D800.4 into it.  I am ecstatic to report that the D800.4 rejects noise just as well as the JL HD in this case.  There is absolutely nothing worse spending hours of time chasing phantoms when the problem could have been solved with careful product selection.

Usage Scenarios Honda Accord Coupe 2008 Source – Pioneer deh-p99rx Front Stage – Hybrid L1v2/Hybrid L3/Exodus Audio Anarchy Subwoofer – SI BM MKIII

Fitment: The small size of the amp provided tons of options.  I tested it for fitment in a variety of unique locations: Rear deck underside (where factory sub option would mount subwoofer) Underneath passenger seat Behind rear seats (you could probably fit 6 of them back there!) Underneath front carpet in passenger footwell
If I were to use this amp in a brand spanking new install, I would most likely locate it on the bottom of the rear deck where the factory option subwoofer would go.  It fits very nicely and could be easily mounted with bolts from the top of the deck, or with self tapping metal screws from the bottom.  Wires could be cleanly run and you would give up 0% of your cargo space.  I know that many of you like keeping rear fill.  Using this amp to push 4 sets of components would be a very good choice and would get loud enough to make you cry.

Performance: I used the amp to push the 2 more power hungry drivers in my 3-way front stage – the woofer and mid.  I felt that having the amp engage the least efficient drivers in the stage would be a good test of its power capabilities.  Additionally, having the amp power the driver that handles the vast majority of sonic information (the midrange) would be an excellent test of its sonic characteristics.
The Massive Audio D800.4 performed very well.  This was the first car that I tested it in, and it immediately brought a smile to my face.  I normally run a JL HD 600/4 bridged to my Anarchy midwoofers, and the Massive D800.4 kept up admirably.  When pushing them very hard with my volume set to the official “show off to my friends” setting, I noticed that the additional power from the JL amp kept things a tad clearer at the low end.  I bumped the high pass filter slope to  24db, and the differences between the 2 amps disappeared.  Right then I knew that the D800.4 was something special. It easily kept up with an amp costing much more, pushing more than 2x the power.  I am sure if I used the D800.4 in the same bridged configuration only pushing my midwoofers, it would give up nothing to the JL.
In the midrange, there were no surprises.  The D800.4 kept my L3′s sounding as clear and beautiful as they usually do.  The L3′s are normally pushed by 2 channels of a JL HD 900/5.  My imaging remained exactly the same despite the amp change, I suspect this could be a testament to the channel separation and frequency response.  Very very nice.

Honda Element 2009 Source – Pioneer deh-p880rs + JBL MS8 Front Stage – Tang Band 25-1719S Ceramic Dome Tweeters/Tang Band W3-1364SA Bamboo Cone/ID OEM Subwoofer – DIYMA R12

Fitment: The small size of the amp provided tons of options.  I tested it for fitment in a variety of unique locations Underneath front seats Underneath rear fold-up seats Inside rear cargo side cubby

Performance: I used the amp to push the 2 more power hungry drivers in the 3-way front stage – the woofer and mid.  I felt that having the amp engage the least efficient drivers in the stage would be a good test of its power capabilities.  Additionally, having the amp power the driver that handles the vast majority of sonic information (the midrange) would be an excellent test of its sonic characteristics.
The Massive Audio D800.4 performed flawlessly in this setup.  They powered the ID OEM’s without breaking a sweat until my doors couldn’t take it anymore.  The sound was deep, full, dynamic, and effortless.  I do feel that there are cleaner drivers than the ID OEM’s available.  However, I feel that the ID’s are a very good test bed, as they consume a ton of power, and sound very weak and anemic when they don’t get the wattage they’re asking for.  My fluttering left pant leg can testify that they were powered adequately and sounded just as good as I have ever heard them.

While I mentioned that I did not expect the ID OEM’s to sound squeaky clean, I did expect this out of the mids.  The Tang Band bamboos sounded crisp, clean, and clear (how’s that for alliteration?).  I was extremely happy, and found myself enjoying my test tracks with my eyes closed and forgot that I was auditioning an amp at all.  I felt that the amp did an excellent job of controlling the woofers and mids in this system and everything sounded as perfect and as dynamic as I could expect.
Additionally, for those of you who haven’t heard, the JBL MS-8 is a DSP that can control up to 8 speakers individually, with automatic EQ’ing, time alignment, and cancer curing.  It is known for setting up a very realistic and wide soundstage automatically through a sophisticated automated calibration process.  When swapping amps out, after matching the volume levels, I did not notice any change in the sound stage at all.  I suspect this could be a testament to the channel separation and frequency response of the D800.4.  Very very nice.

Conclusion I have extremely little to complain about this amp.  The only cons that I have are: Connectors are not on one side. Crossovers do not run full range to infinity. Not tight RCA barrels.

The pros of this amp run a huge list:

Small size allows for a huge range of install opportunities.

Simple industrial design looks and functions perfectly.

Powerful, transparent sound.

Detented pots for adjustment

Runs cool and efficient.

Lack of electrical noise.

Hidden mounting points.

Low noise floor.
I have always been of the mindset that the amplifier should simply amplify.  Anything other than volume that is added to my system is undesirable.  The Massive Audio D800.4 amplifies extremely well.  I was very happy with the dynamics and headroom that it provided my test systems with.  I think that many would be hard pressed to build a system that requires more power.  Only things that would come to my mind would be 8 inch woofers in a door application, or pushing a monster dual voice coil sub.  The sound remained clear and powerful way past normal listening levels in my test systems, and was uncolored throughout.

This amp is the 4th Class D amp model that I’ve had the pleasure of working with, and I am confident to say that Class D has graduated well past its original “non-SQ” reputation.  In real world listening tests, I doubt that normal discriminating listener would be able to pick it out against an identically powered A/B amp.  I only have had brief experiences with the original Alpine Class D amps, and agreed with the general consensus that they had an unacceptably high noise floor.  The Massive D800.4 thankfully did not suffer the same problems, and had a very good noise floor that was not able to be noticed at all during normal usage.

The value of this amp is very high, especially at its current website price @ Massive.  This kind of power out of such a small footprint usually commands a much higher price.  This amp plays the middle pricing ground between the full-size amps and the new mini-amp breed that is attacking the market place.  For installs in locations that are tight, or without much airflow, this is one of the cheapest and best options you can go with.  The quality of sound and build are only the icing on the cake.  It’s been a pleasure testing this amp out and I’m already planning on using it in future installs.
Review By Devin Kato- For Full Review Vist http://www.driveaccord.net/forums/showthread.php?p=772204