TapeHeads Tape Test Report: Denon DX4

[Des-Lab]

It's been awhile since I've done one of these. But since today was a scorcher of a day outside and I was staying inside, it would be a great day to evaluate a tape.

The subject for today is one that hasn't received much attention. But one I thought might be of some interest to you.
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TAPE INFORMATION:
Brand: Denon
Model: DX4 (Type I/Normal)
Length: C-90

Denon was never really all that high in the hierarchy of popularity when it came to cassette tapes. They were (and still are) world renowned for their components. But despite offering a full line of cassettes for years, they just never really received much widespread exposure. Consequently many cassette enthusiasts never had the desire to try them out.

The subject tape for todays review was their top of the line ferric. The version featured was in production from about 1985 to 1991. There was no replacement tape ever made for it.

TAPE DESCRIPTION

The packaging was rather minimalist with not much to offer in terms of flair or graphics. But the signature Denon "pinstripes" along with the color blocks (whose meaning is unknown) made for a simple but attractive looking piece.



Upon opening the packaging, one gets a simple but adequate (double sided) J-card with ample room for writing track listings and any other notes. The adhesive label comes with two sets of "A" and B" side sheets to allow for mistakes and/or re-use. There is also a pair of narrow "spine" labels that are of little value simply because the writing area is so small. The clear, non tinted plastic Norelco case is pretty basic. But the "Denon" name embossed in the plastic is a nice touch.



The cassette itself came in two slightly different versions of the same shell. The housing itself is basic albeit sturdy. It is held together with screws. And the horizontal, center-cut full length rectangular sight windows make for both pleasing aesthetics and ease for which to gauge tape elapsed and remaining. The blue colored semi-spoked hubs are also nice and not generic and appear to be precision molded.

The only thing that separates the two versions is that some DX4's have frosted sight windows while others are clear for the entire piece. The differences are apparent when you compare the images of the above sealed version with theopen specimen shown below.



The DX4 does come with an opaque head-cleaning leader tape. It is white with markings that vaguely resemble directional arrows printed on it. However they do not appear to be timing marks because they are spaced at much closer intervals than the standard 1 7/8 ips.



The tape itself does appear to be of the "red-oxide" variety, being a deep rust color in appearance. The finish appears to be smooth but not consistent in terms of formula.



TESTING METHODOLOGY

When performing any type of sound based tests, it is important to take two things into account: OBjective and SUBjective. The former includes using straight, neutral test tones at various levels and noting how the test subject responds. In the case of the latter, it is using actual recorded source [musical] material that encompasses a variety of styles and intensities in an effort to mimic how the tapes might be used in the real world. It should also be noted that the differences in mono tone (test signal) versus music (multiple tones and frequencies overlayed with each other) can produce significantly different results even when all other parameters are identical.

So for the OBJECTIVE testing, I brought out the Stereophile Test CD. I used the following tones in my experiments:

Pink Noise
1Khz Warble tone
100 htz tone
50 htz tone



For all four tests, I made two test recordings, noting where 1) they would sound as neutral as possible at a given bias setting at 0dB gain input, and 2) at what threshold would the tape saturate into total harmonic distortion. During the initial recording phase, I would adjust the bias while using the decks live, off-the-tape monitoring function until I arrived at what I thought was the most neutral and natural sound. And during the second phase, I would continue to increase the gain input (again using the monitoring function) until the tape would fail as a result of signal overload.


For the SUBJECTIVE phase of the test, I used three musical recordings that I feel represent a good cross section of most of what I like to listen to that also happen to encompass a broad cross section of intensity and depth.

The choices were my standard test songs:

1. "Renaissance Man" By The Ocean Blue, chosen because of it's emphasis on strong electric guitars, percussion, and bass lines.

2. "Fable" by Robert Miles, chosen for its heavy electronic beat, etheral sounding backing synthesizers, upper range keyboard chords, and high pitched female vocals.

3. "Learning To Fly", by Tom Petty, chosen for the clarity of its multiple accoustic guitar overdubs and strong midrange vocals.

To hear a brief snippet of each of the test songs, please view/listen to the video I made of them here.

TESTING DECK

This test was performed on a Denon DN-790R three-head cassette deck using Dolby C type noise reduction.





FINDINGS FOR TEST TONES

PINK NOISE The sweet spot was at a sustained +3 to +5dB on the meters with the bias set to about the -1.5% position. At these settings, the tape tracked perfectly with the original source. Indeed, the pink noise appeared to have more base noise hiss than did the recorded version. While this is not necessarily a plus because it means a deviation from the true original source, for pink noise, it DID sound BETTER on the tape. Base noise [hiss] was present as expected. But was very low and buried beneath just about any input audible to the ears.

1 Khtz Warble Tone The tape was almost a wild card for this one and a true neutral sound was difficult to obtain. The tape held the input rock steady up to +5dB on the meters but after that, basically fell off a cliff in terms of tracking and reproduction, almost like it started to feedback on itself. The bias position could be used with good results in any direction ± 1% of neutral. Going either way yielded the expected results: Increased bias resulted in duller sound but less base noise and vice versa if bias was reduced.

100 htz tone Best, almost perfect sound was achieved with the bias at the -2% setting with the input not exceeding +2dB. Above that and faithfulness to the original collapsed and distortion began to set in.

50 htz tone This one bucked the trend with the above tones and actually sounded best with the bias turned UP to the +1% setting. Held its ground up to +2 dB input but beyond that, the tape surrendered into a mess of saturation and distortion. It would hold with brief peaks to +3, but that's about it.

A brief (< 1 sec) time-lapse image showing me bounce the A/B monitoring between SOURCE and TAPE.




FINDINGS FOR MUSIC CHOICES

For #1, results were adequate, but not spectacular. The sound was true but only up to about 0 to +1 dB on the meters, and bias set to -1.5. Above that and there was a lot of noticeable low end distortion and rolloff.

For #2, this song and tape went together like a hand in a glove. With the gain set to a sustained +3 with peaks to +5, and the bias also set to -1.5%, it was an example of recording perfection, utterly indistinguishable from the original.

And for #3 with the bias tweaked slightly lower to -2% and the gain within the same range, it was also a flawless recording.

CONCLUSIONS

I have long sworn by the quality of Denon tapes. But based that praise on casual and anecdotal experiences and not hard testing and comparisons. Todays tests only confirmed and reinforced what I believed to have already known.

In short, despite this being what outwardly appears to be a red-oxide (i.e. low end, bottom grade) ferric, it is a satisfactory if not outstanding tape by nearly all measures. While not a top-shelf metal where you can push to the upper limits of a decks abilities, for low and medium intensity sources, this is one of the finest tapes I have ever used. This is a tape true to form. Some tapes claim to enhance the sound of the original, that is a deviation of what we try to do with tapes: preserve the original as closely as possible. And that's exactly what the DX4 does and does very well. Whether or not this tape qualifies as a so-called "super" ferric I suppose can be debated. But what can not be argued is that this tape would be a very fine and solid choice for recording where quality, fidelity, and most of all, faithfulness to the original is most important.

Highly recommended.

Thank you for reading.

[Scorpion8]

Denon manufacturing and packaging of this era (the j-cards, tape shells, labels, etc) were above top-notch in my opinion. The tape was some of the best also, but man that packaging is sweet!

[Marc Hugo]

Hi Matt,

That was thoroughly good reading and most informative on a tape I know nothing about. I have some DX-3 - but none of these.

The pictures are top notch too.

Thanks again - Marc

[gamve]

Nice piece Des. Can't say I've seen any DX4's here in Aussie, but after your report I might have a closer look at these babies. I did see one of the Ebay guys had the 50 lots of HD8 and HD7 for opening bids around US $110. Might pay to drop him an email and see if he has the type 1's

[stuartypoorty]

This review illustrates why I like Tapeheads so much.

It is written by Matt in a clear and concise way, the images are far superior to any magazine article I recall and we're not being sold something from a supposedly unbiased reviewer - hi fi journalists usually have an industry background, are too cosy with the manufacturer and are apt to "talk up" a product.

I'll look out for one of these.

[Des-Lab]

Thanks guys. Glad you like the review. I enjoy doing them because I know you guys enjoy reading them. And yeah. I don't have an ulterior motive here. Indeed I just BOUGHT a few more of these under the radar out of the so-called "slush" fund.

Today looks to be a repeat of yesterday. So maybe I'll do another review. But what tape to do....

[close652]

Great review, thank you!
Have you tried with no NR at all?

[bruckner9]

Agree with the others here; super review.

Extremely informative, and full of actual 'useful' info.

Thanks for your efforts.

[Dazen1]

Superb review.

[Nakdoc]

Des,
What fun! A few constructive comments:
If you test with Dolby, use Dolby B. Dolby C incorporates headroom compression, so the breakup levels may differ significantly when you rerun the tests.
Pink noise Tape / source comparisons made during recording should sound hissier and brighter in Tpae mode, since the bias noise is added to the tape's hiss. The effect is to add about 1/2 to 1 dB to the hiss level. A better test would b to record, rewind, and the A/B with the source in play mode. Bias noise dies away after about 30 seconds.
You might add a 3kHz sine or 1kHz triangle wave to your tests to listen for flutter. Some tape shells are unbelieveably bad. The triangle wave, if you can find it, is a phenomenal test for W/F by ear; it is the sum of odd order harmonics, so flutter causes incredible beat frequencies to erupt.

[Naknut]

Top notch job Des. just one of the many reasons I enjoy Tapeheads.net so much.

[faustus]

Thanks, Matt, for the excellent pics and review. I wish these tapes were more readily available in quantity -- I don't think I've ever seen more than single pieces offered.

[VintageFreq]

Excellent job Des! Very in depth and informative. Someday I hope to be smart enough to do review!

Mike

[Mignun67]

Matt, a nice review and great pics. More please, when you have the opportunity.

I have a few of these thanks to fellow forum members but have yet to try one out in anger. I like the looks of the Denon tapes but it's a shame they were so poorly distributed within the UK. As you know, I have done a review of the late Maxell XLI-S as well as the mid eighties Fuji FR-IS. Both are, IMO, superb tapes. I'll be interested to compare them with the Denon DX-4 as well as with That's FX and the various vintages of TDK's AR that I also have.