Sonic-Studio Tech Review

[Conflow]

Tech Review of the Zoom H4 Sound Recorder

Hi All,

Some Moderators may consider this Post as 'Off-Topic' but I consider anything which effects the PTE Program

and 'Member Users' of PTE to be very much on topic ~ particularily if such avoids future 'pitfalls' in PTE usage.

The H4 Sound Recorder has been around for the past few years and has been adopted by the Pop-Music Industry

but also alludes to claim 'professional' recording performance for other sectors ~ sorry,this is not true !

This Recorder has got problems and some of those have popped up here on the Forum and need to be explained...

This in no way detracts from the Recorder once its 'usage-classification' is understood and false claims rejected.

Summary of the H4 Recorder

* It is a good quality Recorder for simple 'Voice-Overs' within the speech range 100.Hz ~ 8000.Hz within +/- 10.db range.

* It suffers from 'clipping' as the VU Meter does not genuinely reflect the actual Recording Level across the above range.

* It has a highly elevated Bass response below 100.Hz and a (firmware) Filter Cut-Off above 15000.Hz. ~ so its non-linear.

* Other issues are SD-Card selection, and Battery Life, as well as LF-Noise.

* All of these issues are "correctable" and are clearly dealt with in the Sonic-Studio Review ~ See link below.

We in Conflow always see a 'Red-Light' when Manufacturers dont publish a Frequency-Response curve and a Noise-Spectra

for Audio products and our doubts have been confirmed with the Sonic-Studio Tests.

Screenshot and Links below.

Brian.Conflow.

Link: http://www.sonicstudios.com/zoomh4rv.htm

[Barry Beckham]

I appreciate your motives for the post Conflow, but am I the only one who doesn't anderstand the numbers and techno speak of this article. Surely anyone who understood all that stuff you would not be in need of the review.

I am in need of the review or would appreciate one, but the nature of it doesn't add anything to my knowledge, because I don't understand it.

I don't have the patients to research what all the technical numbers mean to an actual recording. Am I unique here or am I Mr average who is voicing what many others think. I would love to see a reveiew of this piece of kit from someone who could speak in a language I understand. Maybe including some examples too.

[Conflow]

Barry,

Thats quite simple to explain,viz:-

*

Every bit of good quality Audio gear should amplify all audible sounds equally and its ability to do that

is represented by a horizontal graph which (theoretically) should be a straight line...OK !

*

The Manufacturers of the Zoom Recorders (conveniently) forgot to publish this vital information and you will

not find it anywhere on the Web. It took an independent 'Review Studio' to Test and publish this so that

the relative sound-fidelity could be measured...in others words how "Hi-Fi" is the product.

*

Zoom Recorders 'boost' the Bass frequencies way above the straight line to such an extent that 'sound clipping'

occurs ~ now if you knew that in the 1st instance...would you buy one ??

*

All the other issues such as Batteries, Memory Cards etc; are clearly explained in plain English by the Author

for user information purposes....these were ignored by the Manufacturer.

*

Like everything in life we take a chance when we buy any Product, but knowing its 'weak-points' allows us to assess

the worthwhile-ness and value to of that particular product.

The Zoom Recorders are good products, but the claims are excessive, whilst the performance is moderate !!

All the best,

Brian.Conflow.

[davegee]

Perhaps it would help if it was explained that CLIPPING is comparable with BLOWN HIGHLIGHTS in photographic terms.

What is CLIPPED or BLOWN OUT cannot be recovered.

Brian,

Is it possible, with this unit, to reduce the recording level to avoid clipping?

DaveG

[Barry Beckham]

OK, but is the H4 suitable for our needs and would most of us be happy with the performance and why would the base be amplified to a degree it breaks down.

I don't really understand why that would be done if it is detrimental to the quality

[Conflow]

Dave,

You are absolutely correct ~ that was a good comparison and a good 'after' comment.

On the Forum we essentially have a 'usage problem' where the Recorder is being used

for 'Quality Voice-Overs' ~ and on our Forum we also have some Studio and TV Pro

Members ~ and they will confirm that quality 'Voice-Overs' are the most difficult task

in Audio Sound engineering and they usually use a $7000 Nagra O/B Recorder to do this

or else the Nagra Apres Series for Radio Reporters....tricky stuff !

Yes it is possible to sort out the 'clipping' by direct and indirect means. Firstly you need

a very quite room (lots of Curtains & Soft Furnishings) and a good solid Table or Desk.

Get a large Blanket and fold it so that it completely covers the Desk-Top.

Next thing you want is a 'Baffle' made of MDF or 10mm Ply. about 12"high and 24"wide

cut down the middle so you have 2 sheets about 12x12"each. Join both together with a

heavy fabric hinge so you can place each at 90° to each other. Place the Recorder behind

the Baffle about 18" total distant from your Mouth.

The Recorder should be set to the "Lo-Mic" setting and if it has AGC use AGC No:1 or No:2

Now talk towards the V of the Baffle and you will find that the Bass frequencies are dispersed

whilst the Hi frequencies are O.K. It does require some 'fiddling' till you get the optimum ~

Also a good O/B Mic Windshield will hold the Recorder and go a long way to sorting things out.

O/B=Outside-Broadcast.

Thats what we usually do when recording 'speech' withing moving Trains.

Brian.Conflow.

[fh1805]

DaveG,

All audio recording equipment is capable of clipping the signal. Clipping is not a fault of the equipment it is a fault of the user.

Clipping will occur whenever the input signal strength is such that the recorded signal regularly exceeds a sound level of 0dB. To the human ear there will then be audible distortion of the sound during playback.

Clipping is avoided by arranging the microphone's distance from the sound source so that when used with a particular setting of the microphone input gain control the signal level never exceeds 0dB. In reality a sound recording engineer would give themselves a little more "headroom" and try to keep the peak levels down to about -3dB. (Think of the gain control as a volume control).

So, in answer to your question "Is it possible...to avoid clipping?", the answer is always Yes; but it might be done not by a change to the settings on the recorder but by a change of microphone position.

regards,

Peter

[fh1805]

Brian,

With regards to the "usage" issues...The professionals have the luxury of using expensive kit because it will, to them, be a tax-deductible business item. Us amateurs are looking for something that doesn't cost the earth and that gives us results better than those we were getting with whatever we used previously.

As an amateur, and applying that decision principle to my Zoom H4: i.e. does it do a better job than the previous equipment? The answer is a resounding YES! Moreover, although I bought it primarily to do voice-over recordings indoors at home, I have found it to be a very capable unit for outdoor actuality recordings.

Amateur A-V workers who want to move into sequences that combine music and voice-over must accept that they face a tremendously challenging time. They have a whole new vocabulary to learn and a whole new set of skills to acquire and polish. It might have taken them close on a lifetime to master their photographic skills, yet too many of them think that they can learn to do voice-overs in just a few minutes given the "right equipment".

Sadly for them, their expectations are not going to be met. Having said that, the H4 (and its little brother the H2) would seem to be excellent products for an amateur to use for exploring the production of A-V sequences with soundtracks that consist of more than just music.

regards,

Peter

[Conflow]

Peter,

It goes without saying, I completely agree with you, yes it is a 'New Era' for A/V Enthusiasts

and yes 'new skill-sets' will have to be learnt.

Concerning the 'clipping issue' you are partly correct once the Recorder System is linear as

was in older Analog Sound Recorders. These required pre-emphasis when recording high

frequencies sounds and de-emphasis on playback to linearise the signals back to normal.

Its called the CCIR and NAB equalisation curves ~ European and American respectively.

However Digital Recorders are a totally different animal alltogether for the reason, not only

do they have to 'digitise' the volume levels of the sounds but they have to 'digitise' all the

different audible frequencies of the sounds...and all this in Stereo !

Recording with digital electronics requires expensive AD Converters (Analog to Digital)

of 2 varieties:- A Logarithmic Level Converter and a Frequency to Digital Converter and

and other exotic devices to get the Sounds into digital formats for the Memory Card.

Then we have to do the reverse in Playback with your PC so we can hear live sounds.

We designed and made 'Digital Sounds Systems' as far back as 1997 for Irish Railways

and in those days we could get the box down to 9"x6"x2" in size. Now look at the H2-H4.

Getting back to the H2-H4 ~ the AD Converters in the Recorders would be nothing like

those in the Nagra's nor the Sony Recorders~ in fact they are a compromise where lower

Bass frequencies are not really expected and they would not be expected to Record the

ultra-low 'pop-noise' which is so evident in all Speech, particularily in Male speech which

gives rise to clipping. This is difficult to correct,see below...

Lower Frequeny Waves have very high energy content and are very difficult to 'digitise'

whereas Hi-Frequencies have less energy and are easier to 'digitise' but the higher they

go the more digital noise is created ~ so we have to compromise in Lo-Cost equipment.

Thus the reason for the 'Sound Baffle' I described in my last Post.

I enclose a little graph below which explains what I'm talking about however once

the concepts are understood it is relatively easy to correct these deficiencies which the

expensive Recorders do as a matter of course...thus their Hi-Costs...thats life!

Regards,

Brian.Conflow

[davegee]

Hi Peter,

Maybe I should re-phrase.

I have been working with a 16 track digital studio since they first became available and know the pitfalls of having too "hot" an input.

My experience is with recording musical instruments and not voice so I bow to the experiences of others.

My question, crudely put, was to try to ascertain if the recording level is "automatic" or if it can be adjusted - if it can then I don't see a problem - experience with the machine will tell the user what setup to use. I am not talking about moving the recorder closer or further away from the sound source here.

By the way, Peter, back in the early 50's when microphones were sold with instructions that they should not be nearer than three feet from the sound source, a guy by the name of Les Paul started "close miking" his partner and vocalist, Mary Ford. The recordings they made were used by Audio Magazines etc as an example of how things should be done for many years and the quality still holds up very well. Close miking with the correct setup will, I believe, give a far superior result to the other alternative and produce recordings with far less background noise (when recording the voice).

Anyone have any experience of the EDIROL or Fostex variants of this type of recorder?

The Fostex has: "2 x professional phantom powered XLR mic inputs with precise recording level adjustment control" as well as a built in stereo mic.

DaveG

[Conflow]

OK, but is the H4 suitable for our needs and would most of us be happy with the performance and why would the base be amplified to a degree it breaks down.

I don't really understand why that would be done if it is detrimental to the quality

Barry,

You were looking for a 'simple review' on the H2 and H4 Recorders, but firstly lets get things straight,viz:-

Zoom Model H4 -has- 2 Condenser Microphones and 3 (setting) Level controls and an 8 Function Auto-Gain System

which is great for people on the move. When any of the 8 AGC Programs are selected it cancels the 3 manual settings and

tends to counteract any induced 'clipping'.

Zoom Model H2 -has- 4 microphones, its larger and less 'fiddley' than the H4, but only has 3 Volume Level settings each

with very limited auto-gain (up near maximun level of any 3 settings) and is quite easy to push it into 'clipping' but has other

adaptable features of 'surround-sound' as well as 'directional pick-up'.

Here below is a simple 'Review' of other like Recorders on the Market ~ this page is expandable into each Recorders functions.

Have fun...

Brian.Conflow

link: http://digitalmedia.oreilly.com/audio/port...der-comparison/

[fh1805]

DaveG

...a guy by the name of Les Paul started "close miking" his partner and vocalist, Mary Ford...

...with the correct setup...

...Anyone have any experience of the EDIROL or Fostex variants of this type of recorder?

I regret to say I am old enough (just!) to remember Les Paul and Mary Ford.

Your underlined phrase says it all!

Someone has mentioned the Edirol R-09 on the forum before as I recall.

regards,

Peter

[jfa]

Peter you are not the only oldie here, I learnt to play bass guitar from Mary Ford, (well from her instruction manual), back in the 60s. It's great to see her name mentioned again, brings back lots of wonderful memories of her and Les Paul's music, not to mention what Les did for the guitar.

[Barry Beckham]

Conflow

Thank you

[davegee]

Hi Brian,

Comprehensive review - if lacking a little in detail (apologies - just saw the expandable bit) - but no mention of the Fostex FX-FR2LE?

http://www.scvlondon.co.uk/catalog/product...products_id=673

The Sony also sounds interesting.

I know that it is a slightly backwards step, but for anyone wanting a CHEAPER alternative, there must be plenty of the Sony Mini Disc Walkman units out there ready to be snapped up at bargain prices. I have an MZ-R50 which, when used with SUITABLE Mikes, will produce results comparable with the H4.

DaveG

[Conflow]

Dave & Barry,

Dave, I have found nothing on the Fostex-FX2LE ~ but you are right about the 'Sony Mini Disc Unit' and Sony in general.

Sony have spent a fortune on the entire Walkman series including the Digital-PCMD50 (superb unit) which is more or less the

same price as the Zoom H4 (approx $500). (In comparison the Zoom H2 is retailing about $200 but its an entirely different Unit).

Barry - I have a fair idea of what you like and I would suggest the Sony-PCMD50. its really your type of machine. Others in

the same bracket are the Olympus LS-10 and the Edriol RO-9.

Personally - We were using Digital Recorders in our work but ditched them some time ago for the reason that there is

no (cost effective) 'Digital Graphic Equaliser Software' available on the market suitable for 'Post Recording Editing'....so we went

back to our old Sony's GX-400 and the newer GX-600's, (genuine Cassette Recorders) ~ superb 'auto-level control' and suberb 3

position 'noise-control' and the only things which work effectively in noisy environments such as Trains, Ships, and Aircraft and

their 'ambient silence performance' is excellent ~then thats our Work~ and Sony does the job...what you hear is what you get !!

For Forum 'Voice-Overs' the little Zoom H2 at $200 is hard to beat once you get used to it 'peculiarities' ~ its main feature is the

amount of control over 'Recording Levels' whereas with the H4 these are fixed ~ but they are not Sony !!.

Hope this puts things into perspective...

Brian.Conflow.

[Howard Bagshaw]

I'm a bit nervous of joining in this thread, but I do have some experience of using the Roland Edirol R09, so here goes. What I don't have is enough experience and techy gear to be able to thoroughly test it out, so any comments are going to be quite subjective.

Firstly, Roland do publish a frequency response graph at http://www.edirol.net/products/en/R-09/images/info_03R_L.jpg. OK, it's the manufacturer's own, but I haven't found an independent analysis. Response does rise below 40Hz, but there is a low cut filter available which I find useful for my voice (deep male). Again, there is a peak between 8000-15000Hz, I haven't heard any significant effect of this, but maybe the old ears are letting me down here.

As for noise, again I can only judge from my audio editing software (Audacity) and by listening, but it seems to be low. It cannot be used (to my knowledge) as a USB microphone plugged straight into the computer, an area which seems to whack up the noise in the H4.

I only use it with the manual volume control and there are 30 levels of such control. In addition there is a high/low gain switch which apparently adds about 24dB of gain. The input meters seem fairly accurate and I try to keep the level below 3dB peak, never letting the 'Peak' LED flash on. Using 24bit WAV recording I feel that I have a bit of headroom to avoid 'blowing the highlights'.

Using it for 'ambient' recording is a delight, easy to carry, unobtrusive and quick to operate. The serious problem is its sensitivity to wind noise and I need a windshield or 'dead cat' to help with that. For narration I set it up about 30cm from my mouth, off axis, in a fairly dull acoustic environment and get, to my ears, acceptable results.

For me 'acceptable' is fine. As a device it will always be the compact camera equivalent of sound recorders and knowing that, I try to use it within it's limitations. I'm happy with the results at the moment and having got a FIAP ribbon at a recent AV International using it, it can't be too bad.

Hope that helps, Howard

[fh1805]

Howard,

I'm a bit nervous of joining in this thread...

Don't be - we're a friendly bunch!

It cannot be used (to my knowledge) as a USB microphone plugged straight into the computer, an area which seems to whack up the noise in the H4.

Anyone who tries to use the mic and line inputs to a PC's soundcard for voice-over recording is just asking for all sorts of noise problems. It is just not the right way to go, in my opinion.

For narration I... ...get, to my ears, acceptable results.

For me 'acceptable' is fine. As a device it will always be the compact camera equivalent of sound recorders and knowing that, I try to use it within it's limitations.

And in those two words "acceptable" and "limitations" can be found the secrets of your success. You use it for what it does well and steer clear of things that it cannot handle so well.

regards,

Peter

[Conflow]

Howard,

Your Edriol RO-9 Recorder

Don't be nervous ~thats what the Forum is all about~ unbiased contributions from Members such as yourself.

To me, that Frequency response is more or less in order and what I would have expected from a good Recorder

and I had demonstrated such in a Graph in a previous Post.

Above 10~12000.Hz there is an expected peak which is normal for 'Digital-Recorders' and is usually beyond normal

Adult-Hearing...so no problems there. That peak is normal 'noise-spectra' from the AD Converters and is evident

on all PC's never mind Recorders ~ and the vast majority of Loudspeakers can't reproduce it anyway and more

important Edriol have incorporated a 'switchable-filter' to normalise the peak with a -6.db/octave rolloff. ~Nice one~

I see that its using very good 'Cardoid Condenser Mics' and their 'polar patterns' is what I would have expected from

a quality machine. That pick-up pattern working with the 'switchable-filters' would certainly give a good solid recording.

All in all, a very excellent Recorder in the same league and price range as the Sony.

You have a nice recorder there Howard,

Brian.Conflow.

[Peter S]

I am puzzled as to the seemingly outright rejection of the use of a microphone input to the PC.

Following discussions with one or two people at one of the 123 AV rounds at Aldbourne a couple of years ago I purchased an input amplifier from Howard Gregory. I use this with an AKG C1000 S microphone that is held in a proper stand on the desktop. I record using Adobe Audition and that allows me to monitor the recording level very accurately. The recordings may not be perfect but hiss or hum is really quite difficult to detect unless the volume is turned up to an excessive level. There is of course some noise from the PC if the volume is turned up and there is no sound input!

I am not advocating this as being better than the Zoom and the combination of mic and amplifier worked out at about £160 so it wasn't that cheap. I don't think however that this approach should be rejected out of hand.

I should perhaps also mention that my PC was almost deafening until I replaced the original fans with some much quieter ones. This was however more for my sanity than for recording purposes!

Kind regards

Peter

[Conflow]

Peter,

Let me try and answer this for you: There are 3 Mini-Jack Sockets on most PC's,viz:-

Mic Input ~ Line Input ~ Line Output (The latter is the Signal-outputs to Amps,Mixers etc)

*

The Mic Input ~ This is for Hi-Level 'Electret Mics' such as those which used to come with your PC.

These (cheap) Mics have a Hi-Signal output ( 5-50millevolt) somewhat like the old Crystal Microphones

and they worked into a Mic Socket which is Hi-resistance so they used to pick-up 'Hum & Noise' from their

surroundings should the Mic cable be too long or placed near other electrical apparatus.

*

Unfortunately PC-Owners "assumed" that the Mic Socket would accept a quality Dymanic-Microphone

which is somewhere near 600.ohm (Lo-resistance) and very low output signal...usually less than 1.Millevolt.

Of course there was a total electrical "mis-match" and the consequence of this was lo-recording levels and

very high Hum & Noise.

That erroneous "assumption" is still truly well and alive to this present day....thats your answer !

*

The Line Input ~ This was designed to accept Hi-level Signals (nominal) 750.millevolt into 600.Ohm load

but usually set about +1000.ohm load. The 'Hum & Noise' levels here are very low and in modern PCs is about

-60.db or lower. In plain English thats about or less than, one/thousand of the Input Signal expected.

*

AKG Mic and Amplifier ~ Thats the correct way to do this job, a decent Mic and Mic pre-Amp with Volume

Control and some Filter Switches and a Mute Switch. But because this is getting technical most Forum Members

would shy away from such ~ more's the pity, because they don't know what they are missing !!!

*

Another Simple Solution

Below is a Snapshot of the 'Griffin iMic System' (iPod Technology) which gives superb 'Voice-Overs' and it appeared

on this Forum about a year ago ~ I was surprised with its performance and shocked that more Members didn't give

it a try...thats life.

Regards,

Brian.Conflow.

[Peter S]

Hi Brian,

Thanks for the response. I would be interested in trying the Griffin iMic with reservations! My first mic was a Samson USB version and I could never get anywhere with it and exchanged it for the AKG. Does that indicate that the iMic would cause similar problems? I am not sure if this may have had something to do with not being able to get an input to Audition but it was a while back and having found a solution I had almost forgotten the original problem.

Kind regards

Peter

[Conflow]

Peter,

You might send an EMail to 'Tomuk' who uses the Griffin as I do, and he had a wonderful demo of this on MediaFire.

The Griffin iMIC is totally different in technology compared to the 'Samson Intergrated-USB Mic' in fact it doesn't have

a Mic in it. You supply the Mic and any other Sound-device which requires conversion to USB Technology which then

completely by-passes the internal Sound-Card in the PC. The Sound signals are now Digitised PCM (no-noise), thats

probably the reason you couldn't get an input to Audition, I don't think it supports PCM ~ Audacity does.

The Griffin incorporates the Stereo A/DConverters somewhat like those used in the Zoom H2/H4 Recorders and

that quality is purely dependent on the Mic(s) deployed.

Brian.Conflow.

[davegee]

Brian,

EDIROL also offer a number of USB Audio Capture devices one of which is:

http://www.ediroleurope.com/product_overvi...&country=GB

I have used a more basic Edirol UA-1D to interface between a variety of optical output equipped devices such as the MD Recorder, the 16 Track Recorder and my PC for many years very successfully.

DaveG

[Peter S]

Hi Brian,

You say in your post

"The Line Input ~ This was designed to accept Hi-level Signals (nominal) 750.millevolt into 600.Ohm load

but usually set about +1000.ohm load. The 'Hum & Noise' levels here are very low and in modern PCs is about

-60.db or lower. In plain English thats about or less than, one/thousand of the Input Signal expected."

Are you advocating using the Line Input rather than the mic input? I have been unable to detect any signal from the mic through the Line Input - and yes I did change the input source in Windows Volume Control but ... have I missed something else??

I have been using the mic input on the front panel of my PC with the signal boosted by the amp and the volume control set as low as possible to minimise the noise level in the recording.

Kind regards

Peter