Magazine Archive

Home -> Magazines -> Issues -> Articles in this issue -> View

Bass: The Final Frontier

Richard Allan RA8 Monitors and RA12 Sub-Bass Units

By combining two of their compact RA8 monitors with a pair of sub-bass units, RA have come up with an earth-shaking system at a realistic price.


Based on Richard Allan's established RA8 monitors enhanced by the RA12 sub-bass units, this full range, cost-effective system boldly goes where Paul White has never gone before...


The majority of recording work can be undertaken on near-field monitors with a reasonable degree of success, but there are certain musical styles that have to be checked out on loud, full-range monitor systems. Obvious examples are dance, rave, reggae and heavy metal, where the bass element is a particularly important component of the mix. The problem is that most full-range studio monitoring systems are extremely expensive, very large, and require banks of powerful amplifiers to drive them.

Before getting too far into the concept of the system under review, it's useful to cover the important points of the RA8 monitor on which the system is based. Featuring a 180mm bass driver, with a synthetic cone supported by a roll rubber surround, plus a 25mm soft-domed tweeter, the RA8 is the latest incarnation of a small, two-way monitor originally developed for broadcast monitoring; I understand that the original version enjoyed considerable success with the BBC. The enclosure is an infinite baffle design (which simply means that it isn't ported) and is made from 19mm high-density particle board finished in black woodgrain. The treble unit covers the range 3.5kHz to 20kHz, while the bass/mid driver extends down to 60Hz. A passive crossover arrangement working at around 3kHz is employed, which includes provision for bi-wiring if required, and the crossover circuitry is hard-wired to minimise unwanted resistance. Connection is via gold-plated, heavy-duty terminals located in a recess on the rear panel; there are two sets of terminals joined by a movable link which must be removed for bi-wired operation.

Richard Allan have been very conservative in their power rating for this speaker, quoting 50 watts continuous or 100 watts programme material, and the overall efficiency of 91 dB for 1Watt at 1m means that there's plenty of available volume, even with a relatively modest amplifier setup. Used on their own, the RA8s make perfectly satisfactory near-field or hi-fi monitors and have a very clear, detailed sound. They have been deliberately voiced to sound a touch bright, presumably to appeal to NS10 users, and when the removable foam grille is taken off, they sound a hint brighter still, so it may be as well to leave the grilles on.

The RA12



The RA12 comprises a single HP12B driver, a 300mm device with a 270mm laminated Bextrene cone supported by a soft roll rubber surround and suspended in a die-cast aluminium chassis. The two-layer, 50mm voice coil is copper, wound onto a Nomex former, and is bonded with high temperature adhesives to prevent things flying apart in times of stress. The voice coil has a long winding which has been designed to remain in the high-flux magnetic field at all times, to maintain linearity (and hence low distortion) at high operating levels.

Mounted in a ported cabinet measuring 660 x 498 x 398mm, the driver is rated at 125 watts continuous sine wave or 200 watts of programme. The most relevant figure is the recommended amplifier size for the whole system, which is specified as being between 100 and 150 watts continuously rated.

The cabinet dimensions have been carefully chosen to minimise standing wave formation and the front corners of the box have prominent chamfers to minimise diffraction effects from the cabinet edge. Additionally, the driver has been mounted off-centre so that any remaining diffraction effects are distributed, rather than being allowed to pile up at one frequency. Again the material is 19mm MDF, the structure being internally braced and damped, while the outside is finished in a black splatter finish; this is both attractive and practical in that it could be painted over if necessary. A removable foam grill completes the picture.

Connections to the unit are located on the rear panel, again in the form of gold-plated terminals. The set at the bottom of the cabinet is connected to the amplifier and the top set feed out, via the crossover, to the RA8 Series Ms. The crossover frequency has been set at around 200Hz.

Sound Check



Driven from an amplifier rated at 100 watts per channel, the system delivers a solid, clean sound with quite enough level for monitoring. The sub-bass speakers add the kind of kick and weight that is impossible to achieve using small speaker systems, while the bass seems quite even and well controlled. As touched upon earlier, used in isolation, the RA8s have a bright, forward sound and the RA12 bass unit appears to have been designed to balance this. The result is that the mid-range is slightly overpowered by both the lows and highs, making it sound a trifle recessed — this gives the system a slightly hard sound. If anything, the bass is a tad over-generous, which means that positioning the speakers near corners is to be avoided, as the bass is likely to get out of hand. The manufacturer's published frequency response for the complete system confirms both these observations. Changing the crossover design might have improved this situation, but as the system includes standard RA8s, this was not possible. It's only when the system is compared directly with known accurate speakers or headphones that this shortcoming shows up, and to be fair, many dedicated studio monitors exhibit similar characteristics. You very soon get used to the sound, but as a midrange imbalance can affect the way in which you balance vocals in a mix, it is advisable to familiarise yourself with the system by playing known records through it. I tried patching in an Alesis 230 equaliser between the CD player and power amp and set a broad boost centered at between 250 and 300Hz and peaking at around +4dB, in conjunction with a couple of dB of top cut around 6-8kHz.

I arrived at these figures in an entirely empirical way, by comparing the sound from the speakers with that from a pair of AKG K500 headphones and, while this is not a reliable way to quantify the bass end of the spectrum, it is quite a useful way of checking the mid and high balance. The result was, subjectively at any rate, a great improvement in the quality of the mid-range and a reduction in high-frequency harshness. While equalisers should never be used to try to correct an acoustically imperfect room, it is not unreasonable to use them to level out a speaker system that is known not to be flat, and they can also be useful in adjusting the level of bass when speakers have to be positioned close to walls or corners.

Summary



RA8 AND RA12

PROS
  • Cost-effective, full-range system.
  • Reasonably efficient, enabling less powerful amplification to be used.
  • Clear, very powerful sound.

CONS
  • Physically large bass cabinets.
  • Can sound 'hard' due to mid range dip.

PERFORMANCE 7/10
VALUE FOR MONEY 8/10

Richard Allan are an English company with a long tradition of loudspeaker manufacture, and the system under review appears to be well engineered given its relatively modest cost. My only real criticism is the mid-range dip, which comes about primarily as a result of the deliberately bright voicing of the RA8 - but then a very large number of people like to mix using NS10s, which I find equally over-bright. As explained, this can be counteracted to a large extent by the use of a graphic equaliser.

In its favour, the system delivers a very powerful sound which remains clean up to high listening levels. The high efficiency of the drive units, combined with the all-passive crossover system, means that the whole setup can be run from quite a modest power amplifier, and the fact that the bass cabinets are physically separate from the smaller RA8 cabinets allows for a certain amount of leeway in positioning.

For the same money, you can buy rather more accurate near-field monitors, but I know of nothing else at this price offering a comparable degree of bass extension. In conclusion then, I'd say that if you need to be able to monitor with a lot of power to satisfy your heavy rock, reggae and rave clientele, then this Richard Allan system is very cost effective, yet clean enough to be musically discriminating. Though the performance can't be guaranteed, the bass units can be used with other types of small-two-way speaker, and I plugged in a pair of JBL control 1 s just to see what would happen. The mid-range was definitely out of balance but the massive extra bass was pretty impressive if you like that kind of thing.

It might also be interesting to try out the package as a high-quality sound system for small synthesizer gigs, where the powerful bass end and good overall clarity could prove very impressive. Indeed, if I had the room, I'd love a system like this in my lounge to go with the NICAM TV. Add Dolby surround sound and the Terminator II video would never sound the same again!

RA12

In order to extend the performance of the RA8s to cover the full audio range, Richard Allan developed the RA12 low-frequency enclosure to take the low-end response down to 30Hz. This wasn't such an easy task, as the new bass system had to be made to work in conjunction with the existing RA8s, which meant that the upper crossover characteristics couldn't be changed. Unlike some sub-bass systems which utilise a single bass enclosure, the Richard Allan approach was to use a separate bass cabinet to accompany each of the RA8s, each bass cabinet incorporating a passive crossover. These cabinets may be positioned under the RA8s, but equally they could be placed together in the centre of the soundstage or located to some other point in the room if necessary. Ideally, the distance between the listener and the RA8s should be similar to the distance between the listener and the bass units but, because of the relatively long wavelengths involved at these low frequencies, it is usually possible to bend this rule slightly without significantly compromising the sound. However, you do have to be careful where you position the speakers relative to walls and corners, and the instructions provided are very helpful on this point.



Further Information
RA8 Monitors £270.25 per pair; RA12 Sub-bass units £705 per pair. Prices include VAT.

Richard Allan, (Contact Details).


Also featuring gear in this article



Previous Article in this issue

Live Sound

Next article in this issue

RM Competition


Recording Musician - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.

 

Recording Musician - Nov 1992

Donated by: Mike Gorman, Colin Potter

Scanned by: Mike Gorman

Review by Paul White

Previous article in this issue:

> Live Sound

Next article in this issue:

> RM Competition


Help Support The Things You Love

mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.

If you value this resource, you can support this project - it really helps!

Donations for January 2022
Issues donated this month: 3

New issues that have been donated or scanned for us this month.

Funds donated this month: £141.00

All donations and support are gratefully appreciated - thank you.


Magazines Needed - Can You Help?

Do you have any of these magazine issues?

> See all issues we need

If so, and you can donate, lend or scan them to help complete our archive, please get in touch via the Contribute page - thanks!

If you're enjoying the site, please consider supporting me to help build this archive...

...with a one time Donation, or a recurring Donation of just £2 a month. It really helps - thank you!
muzines_logo_02

Small Print

Terms of usePrivacy