Urei 809 review
For the response curve see the attachment
In this two part feature, Ken Dibble reviews two closely related but very different monitor loudspeakers: the new Urei baby, the 809 and the well established JBL 4425.
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Urei 809 and JBL 4425.
It was widely expected that with the takeover of Urei by Harman Audio during 1985 and its integration with JBL, there would be some rationalisation of Urei's loudspeaker interests, as, let's face it, JBL and Urei between them probably account for the largest slice of the Stateside monitor loudspeaker business and had been keen competitors for many years.
However, it turns out that this is not the case, and having visited both JBL and Urei in California last Autumn, and seen first hand the way things are done in the studios around LA, I can quite see why both are to continue as separate lines, each retaining its own separate identity, although there does seem to be a graduated integration of componentry taking place.
But notwithstanding the fact that both review systems employ a JBL 30cm low/mid driver in a tuned reflex enclosure, both have constant directivity type HF horns and employ exactly the same JBL compression driver, the two products are most definitely not the same, having quite individual voicing signatures, technical features and design concepts.
Both brands are of course giants in the world of monitoring in both film and sound recording studios, whether for original takes, mixdown, editing, pre-viewing or mastering. Each engineer has his own very definite preference for one type of monitor over another, and although the particular samples being reviewed are the babies of both ranges, the differences in timbre, emphasis, imaging and the like are clearly identifiable. Not being a recording engineer, and therefore finding myself a little distanced from this love affair relationship with one particular loudspeaker type, I have tried to take a more objective look at what the differences actually are between the two models to be reviewed, and have based my conclusions on a combination of laboratory testing and subjective evaluation.
However, noting the present day tendency towards esoteric reviewing in certain of the technical press, often at a technical level way beyond the understanding of even competent engineers, and dealing in vague notions of performance criteria that cannot be related to what is actually heard without the aid of a computer, I have tried to keep to an even keel and restricted the laboratory testing to the basic parameters of immediate concern.
Laboratory Testing
Both review samples were tested in the anechoic chamber at GEC-Hirst Research, driven by an HH Electronics MOSFET V800 power amplifier and using precision calibrated Bruel & Kjear instrumentation. The testing programme was supervised by the author in person and was overseen by the head of the Acoustics Section at Hirst, John Edward.
The tests carried out included an impedance/frequency plot, a sine wave/frequency plot at 1W with the measuring microphone one metre distant from the loudspeaker baffle panel, a second sine wave amplitude/frequency plot at 6dB below rated system power showing the second and third harmonic distortion components present, and a family of horizontal polar response plots. This data is considered to provide a fair technical appraisal of a loudspeaker's basic performance characteristics. All these curves will be published in the test results section along with a tabulated summary of the performance parameters measured.
One further test was carried out in my own laboratory using an Ivie IE-30A/17A set-up in order to test out the time alignment data provided as this performance aspect features quite highly in the maker's published literature for both products, and in any event, the Urei 809 is specifically marketed as a time aligned system, and should therefore be tested as such.
Subjective Assessment
The loudspeakers were evaluated separately in pairs and singly by AB comparison over a several week period using my own auditioning set-up, comprising a Mission DAD7000/R compact disc player, Hafler DH110 control amplifier and Hafler DH220 power amplifier.
For all tests, the EQ section of the DH110 was switched to bypass and no graphic equaliser was used. The source material included Dire Straits 'Alchemy Live' and the obligatory' Brothers in Arms' albums, Tina Turner's 'Private Dancer', Joan Armatrading's 'Secret Secrets', Joe Cocker's 'Civilised Man' and the Shostakovich 5th symphony by Leonard Bernstein with the New York Philharmonic Orchestra from the CBS/Sony Masterworks series, all on CD. The HFN test disc was also used.
Urei 809
General Specification
Drive unit compliment
Single 30cm lo/mid cone with co-axially mounted constant directivity HF horn and compression drive unit.
Crossover
Internal passive 2-way incorporating group delay time alignment elements.
User Controls
HF Drive, HF Trim.
Cabinet loading
Direct radiating 65Ltr tuned reflex.
Impedance
8Ω nominal.
Termination
Screw terminals/4mm sockets.
Power Rating
28.5 volts for 1 hour with band limited pink noise 50Hz-20kHz (100W).
Sensitivity
93dB for 1W at 1 metre.
Rec Amplifier
150W RMS/8Ω minimum.
Dimensions
585mm high x 420mm Wide x 345mm deep.
Weight
27kg.
Finish
Utility black fleck paint.
Price
£805.00 each suggested retail, including VAT.
Design Concepts & Presentation
The 809 is the baby of the legendary Urei 800 series monitor and is intended for use in smaller control rooms where the somewhat large dimensions of the 811, 813 or 815 would be inappropriate, and for general purpose near-field monitoring. As with its larger forebears, the design concept targets for a flat power response at low distortion levels and centres on the co-axial single point source and time alignment principles to provide accurate time domain response, accurate stereo imaging and uniform soundfield. The units have to be ordered as right and left handed versions to further these design objectives by correct placement of the drive unit assembly in relation to the bulk of the enclosures.
Presentation is definitely utility-orientated, with the drive unit assembly and crossover module screwed directly to the cabinet front with no fret panel or protective grille. Also on the front panel, under a foam plastic insert, is the reflex port, the input terminals being recessed into the back panel.
Constructional Aspects
The enclosure is a simple box of 18mm high density chipboard, with ample internal softwood bracing, lined and damped with high density fibreglass batts. It's a one-piece assembly with no removable panels and has a particularly rigid and solid feel to it. Still further absorption is provided by a liberal stuffing with low density fibreglass quilt.
The tuning port is fairly large and square with a short plywood duct which is slotted down its length, and it may be noted that an identical apperture is provided to form a housing for the crossover module below, the slot being utilised to locate the circuit board. Thus, to form a left or right hand version of the 809, all that is necessary is to mount the drive unit assembly the other way up and reverse the tuning port and crossover module positions, thereby enabling either version to be assembled from the same cabinet shell. Clever, these Yanks!
The drive unit itself is a substantial affair, comprising a heavily ribbed and damped 30cm piston carried by a high compliance foam front suspension system and featuring a double spider rear suspension arrangement to ensure absolute piston linearity. The voice coil details are not published but this would appear to be of copper ribbon on a 75mm former. A large ceramic magnet assembly is used, with a hole bored through the centre of the pole piece terminating in a threaded boss in the back coverplate to provide a coupling for the HF compression drive unit. Although unmarked, it's unmistakably a JBL transducer in all respects. The compression driver is the new JBL 2416H but bereft of any casing or frills, and this too is a fairly substantial piece of ironmongery, resulting in an impressive coaxial drive unit assembly of considerable mass and engineering.
At the centre of the lo/mid piston is the familiar Urei 'blue horn' complete with its PVC foam 'icing' and its soft PVC side panels to provide that soft-edged, ring-free HF sound for which Urei monitors are justly famous.
Over the years this horn has become almost legendary amongst the West Coast recording fraternity and even if with modern technology it were to be proved that it didn't serve any useful purpose at all, it would have to be there, even if only as a mascot!
The crossover unit is built on a printed circuit board attached to the control panel and is internally supported to prevent the board fracturing under the weight of the large air cored inductors and substantial capacitors and wire wound resistors carried by it. Both response shaping controls are in the form of substantial ceramic cased wire wound potentiometers. It was also noted that the conductive track of the PCB and the wiring used are of larger cross sectional area to handle large current transients with minimum voltage drop. It is also interesting that with the Mexican border not too far away from the Urei factory in San Fernando Road, Sun Valley, CA, and a notable Mexican presence all around, that many of the crossover components used are actually made in Mexico!
Although shipped for installation with the long dimension in the horizontal plane, if control room conditions dictate, it's an easy matter to rotate both the drive unit assembly and crossover control panel through 90° and mount the cabinet vertically instead. This will not effect performance in any way.
Test Results
The impedance/frequency curve is shown in Figure 1. The minimum impedance value occurs just after the fundamental resonance, which is as it should, and does not fall below 5.5Ω. Most power amplifiers should not therefore be in any way stressed in driving the 809, but connecting two in parallel, thus halving the load to 2.75Ω, may present thermal difficulties to certain amplifier designs. The fundamental resonance is unusually suppressed suggesting a relatively low magnetic flux density in the air gap, and the two pronounced peaks at 1.2kHz and 3.5kHz can only be due to compression drive unit diaphragm resonances and to crossover characteristics.
Figure 1. Urei 809 Impedance/Frequency curve
The amplitude/frequency curve is shown in Figures 2a and 2b. It became necessary to provide two separate plots in order to show clearly the effect of the HF Drive and HF Trim controls. Figure 2a shows the frequency response range available by adjusting the HF Trim control over its full operating range with the HF Drive control at its maximum setting, whilst Figure 2b shows the effect of varying the HF Drive control over its full operating range with the HF Trim control at its maximum setting. It will be clear that the two controls act quite independently and that between them, a wide range of response characteristics are available to suit individual control room acoustics and individual preferences.
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Figure 2a. Urei 809 Amplitude/Frequency response showing HF Drive control range @1W.
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Figure 2b. Urei 809 Amplitude/Frequency response showing HF Trim control range @1W.
Derived from these curves, the basic sensitivity of the complete loudspeaker system works out at 95dB for 1W at 1 metre and the useful frequency response at 50Hz-15kHz if we ignore the HF spuriae at around the 20kHz mark. Note that 95dB is 2dB better than the maker's specified sensitivity figure.
Figure 3 shows the second and third harmonic components at 6dB below full power sine wave and it can be seen that apart from the usual rising second harmonic characteristic from the compression drive unit, the distortion components are of a very low order, being negligeable over the working range of the low/mid cone driver, rising to 10% at 10kHz.
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Figure 3. Urei 809 Amplitude/Frequency response showing 2nd and 3rd harmonic distortion at 6dB below rated power.
Figure 4 shows the horizontal polar response curves at 800Hz, 2kHz, 5kHz and 10kHz and it can be seen that a tight forward sound field of approximately 60° is obtained with good uniformity, especially over the frequency range covered by the horn and compression driver section. This type of polar characteristic will ensure a high direct-to-reverberant ratio and good source location and stereo imaging within the direct field of the loudspeaker.
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Figure 4. Urei 809 horizontal polar response.
The time alignment test with the measuring microphone 1 metre in front of the baffle panel gave 3.5mS for both drive units, thus showing zero time error and confirming the maker's time alignment design objectives. The resolution of the measuring system used is 0.1 mS.
Tabulated Test Data
Nominal Impedance 8Ω.
Minimum Impedance 5.5Ω at 100/200Hz and 1.9kHz.
Fundamental Resonance 62Hz.
Sensitivity 95dB@ 1W average 80Hz-16kHz.
Useful Response 50Hz-16kHz.
Distortion Negligible below 2kHz, rising to 10% at 10kHz at 6dB below rated power.
Time Alignment Zero error.
Horizontal Polar Response 100° @ 800Hz included angle @ -6dB points.
60° @ 2kHz included angle @ — 6dB points.
60° @ 5kHz included angle @ 6dB points.
50° @ 10kHz included angle @ -6dB points.
Auditioning
I don't think I have ever been so excited by any one product in all the years I have been reviewing loudspeaker systems. This may have something to do with the fact that I have always liked the West Coast sound and that much of the test material I use is East Coast recorded or mastered. But the sheer guttural clarity and presence of the vocals, the screaming electric guitar contrasted with the smooth, crisp articulation of the acoustic guitar, and the driving attack of percussion instruments, on all the test material previously listed, is something I have not before found combined in a single loudspeaker. And the sound stage imaging is absolutely superb.
The 809 is clean, totally transparent and honest. Try playing a less than perfect recording, perhaps a revamped AAD compact, a bog-standard non NR Fe tape, or anything less than the very best Supercut black vinyl through it and you'll see just what I mean. It's totally unforgiving and won't let you get away with anything!
All of which I find surprising, bearing in mind the LF roll-off characteristic below about 80Hz and the sudden death HF limit at 16kHz as shown in Figure 2.
Also it's loud. The Hafler DH220 is capable of 175W per channel into 8Ω, and a programme level of 106dB(A) SPL in the listening room is totally clean and distortion free. It is also a subjectively loud loudspeaker: far more so than the 95dB sensitivity figure and the 100W power rating would suggest.
Just one reservation. It did not do justice to the Shostakovich 5th: woolly basses, woodwind and cellos and generally lacking in presence, although strings percussion and wind sounded fine. My 12 year old LNB Paralab 20s at home provide a far more natural orchestral balance and timbre than do the 809s, but then, LNBs can get nowhere near the transparency, the imaging, or the punch, drive and attack of these 809s on modern music. It's a matter of horses for courses.
Conclusions
There is certainly no trade-off in any area that will adversely effect performance. It's a superbly engineered loudspeaker designed for practical application rather than to sit in a corner and look pretty. But nevertheless it does have a certain functional attractiveness about it and definitely 'looks the business' as a no compromise tool for the job.
Its performance is affected by positioning and installation considerations and it does need an adequate power amplifier. Although the response controls provided are effective and provide a useful adjustment range, the performance of the 809 can be further enhanced by the use of external electronic equalisation, but only within the headroom constraints of the associated power amplifier and the displacement limitations of the lo/mid piston assembly.
A useful and informative owners manual is included with the delivery.
Next month I will be looking at the JBL 4425.
Reply With Quote
Originally Posted by Ian Mackenzie
I haven't heard anything else that makes a cymbal sound like a cymbal should, as well as reproducing the liveliness/excitement of the entire drum kit. The 811C's I've got paired with the M&K MX350THX subs don't make the midbass magic that the 813C's + 2245's do, but considering how much smaller their foot print is, it could be close enough for some. They at least still have that shimmer and beautiful midrange. I can also tell that the gear I've got driving the 813C's is much better than what is driving the 811C's. Also, as much as I want a pair of 809's to complete my UREI collection, their sensitivity (91dB) is a bummer compared to the 811C (97dB). Therefore, the 811C would be a better choice for low watt amplification.
