Klipsch La Scala AL6 Loudspeaker Review

1963 was a seismic year that changed the world. Martin Luther King delivered his famous "I Have a Dream" speech. US President John F Kennedy was assassinated. The Beatles released their first LP, and Decca signed an unknown band called The Rolling Stones. Whatever happened to them?

Meanwhile, in Hope, Arkansas, USA, a certain Paul W Klipsch was busy creating the La Scala – a 3-way full-range horn-loaded loudspeaker with a very high 103dB sensitivity. A smaller and more affordable version of the brand's mighty K Horn, it proved hugely popular.

Having been in production for over sixty years – and still going strong – today's La Scala has been heavily revised, but its basic size, shape, and fundamental design remain essentially the same. While it's a big speaker by domestic standards, La Scalas are actually small for a proper full-range horn. The latest AL6 version is easily the most radical redesign the speaker has undergone since its introduction six decades ago.

Bass now extends down to 40Hz, from 50Hz for earlier models. This was achieved by reducing the woofer diameter from 15 inches to 12 inches and adding reflex vents to the cabinet. The original 2-foot-long exponential midrange horn has been replaced by a considerably shorter Tractrix horn with a 3-inch K-II33-HP compression driver. The midrange horn features raised sections that Klipsch Chief Designer Roy Delgado calls 'Mumps technology'. The aim is wider dispersion and a less peaky response. The redesigned K-771 horn tweeter now has an extended phase plug for smoother highs.

The new AL6 can be driven conventionally with a single amplifier via its internal passive crossover, or actively by three amplifiers using a Klipsch Heritage AL6 external electronic crossover. This incorporates DSP and time delay to improve the speaker's phase coherence.

The Listening

The key virtue of Klipsch's La Scala has always been its tactile immediacy and presence. Want to feel the band is playing live right there in your front room? Then this is for you. Okay, but what about horn colourations – isn't it also 'boxy', 'shouty', and tonally hard, as some critics have said over the years?

Not anymore. Perhaps such criticisms could be levelled at early La Scalas of four decades or so ago, but later revisions refined tonal anomalies without sacrificing the vivid 'you-are-there' presence and impact that made this loudspeaker famous. The redesigned midrange and high-frequency horns offer wider dispersion and are largely free of conspicuous colouration. Nevertheless, this speaker is not polite or genteel – it has great impact, with crisp attack that mimics live instruments.

Listening began with the speakers in passive mode, driven by a single amplifier – a Synthesis A100 Titan. This features eight KT-66 output tubes, delivering 100W per channel. However, the high efficiency of the AL6 means it could just as easily be used with, say, a 15W amplifier and still play very loud. The source was a Hifi Rose RS151 streamer. I started with something atmospheric – a recording of pianist Lang Lang playing Evocation from Albeniz's Iberia suite.

The piano sounded full, rich, and vibrant, with smooth mid and top. The presentation was well-balanced, clear, and delivered with complete ease. Peaks were hitting around 67.4dB, but the piano didn't sound bright or loud. It was nicely sonorous and full-bodied. Unexpectedly, at the end of the piece, Lang Lang got up and walked off-stage. His footsteps sounded uncannily real, like one was actually present in the venue itself.

The third movement of Shostakovich's 15th Symphony with Santtu-Matias Rouvali and the Royal Concertgebouw Orchestra provided a massive contrast. The bright, spiky orchestration was rendered in a suitably crisp, incisive manner, sounding impressively brilliant and tactile. Staying with the Royal Concertgebouw, the third movement of Brahms' 2nd Symphony on a new Deutsche Grammophon recording with Sir John Eliot Gardiner sounded absolutely exquisite. It was gorgeously rich and spacious, yet effortlessly detailed. The music was tonally natural, with nice woody timbres and oodles of delicate detail.

Stereo imaging was surprisingly precise. I say 'surprisingly' because large, wide speakers like the AL6 typically produce stereo imagery with a broad, generalised spread that's not pinpoint precise. Yet this was really good, and way better than expected. The soundstage was clearly defined. I regularly hear K Horns – with the same midrange and tweeter as the AL5 La Scala – but they don't deliver stereo images as well-resolved as those of the new AL6.

Human voice is a good test for speaker colouration. On a recent Sony recording of Liszt's beautiful Via Crucis for choir and piano with Leif Ove Andsnes, the AL6 sounded authentic and true. A small body of singers is used, and one could sense specific individual voices within the group. A palpable sense of the venue's acoustic was conveyed, creating an impression of singers and pianist performing right in front of you. The result was expressive, detailed, and highly involving, but also effortless and easy to listen to.

The new La Scala reveals subtle changes of mood and atmosphere very clearly. I played Vexilla Regis, the opening of Via Crucis, then went straight to track 7, Sancta Veronica. There was a subtle change, and it didn't sound like the exact same people were singing. It was as if there were one or two singers less, or their positions in front of the microphones had changed. Later, I compared both tracks on my Klipsch Cornwall IVs, and also sensed a slight change, but the contrast wasn't as pronounced as it had been on the AL6.

This is a speaker you can't easily pigeon-hole. On a broad range of music, it kept surprising me. The sound could be smooth, sweet, and refined one minute, then bold, tactile and assertive the next. The essential nature of each recording was laid bare. Although its bass goes down slightly deeper than the previous AL5, the bottom end isn't massively extended. The quality of the lower frequencies is excellent – tuneful, articulate, and fast – but really deep bass isn't there.

Playing I'm an Old Cowhand from Sonny Rollins' album Way Out West, the saxophone sounded rich and fruity, while Shelly Manne's drums reproduced crisply. But Ray Brown's acoustic double bass was backward and lean – I get noticeably stronger/fuller bass from my Cornwall IVs. From listening at a distance of about 8 feet from the speakers, I went to the rear of the room, about 12 feet back. At once, Brown's bass became deeper, fatter, and less recessed. So, getting well back from the AL6 helps deliver a fuller bottom end. Alternatively, add a sub.

Passive Vs  Active

Changing to active involved replacing the Synthesis tube amp with a solid-state Musical Fidelity M6s preamp and M6x 250.7 seven-channel power amp. Changeover took about ten minutes and involved removing six short cable links from each loudspeaker. Active sees each speaker unit driven by its own individual amplifier, with no crossover components in the signal path. Results were more focused and immediate, with a smoother tonal balance. The sound seemed cleaner and more refined as well.

In My Life from The Beatles' Rubber Soul album sounded very good in passive mode, but active mode increased clarity and immediacy. The sound had even greater presence and bite, and John's voice was noticeably cleaner. Oddly, in passive mode, his vocals had a slightly rough edge. George Martin's 'Elizabethan piano' solo was more tactile in active mode, and I could hear subtle background vocals more clearly. Stereo soundstaging was crisply 'left and right' with voices and instruments more precisely compartmentalised.

Curiously, on some recordings, active mode sometimes appeared a wee bit less forward than passive, giving the misleading impression that active was slightly subdued. Not so. Active was noticeably more dynamic and focused than passive, and it was also cleaner. Additionally, it sounded more precise, making passive seem slightly smeared and vague, albeit not in an unpleasant way. Active was more revealing, clearing away all the grunge. It lets you hear everything more clearly, mainly for the better, but also sometimes for the worse.

The Klipsch Heritage AL6 Active Crossover (£3,499) features two knobs that adjust the volume of the woofer and tweeter. They're like tone controls, but not quite. Rather than selectively boosting or cutting low and high frequencies, they alter the output of the drive units. Increasing the bass control makes the woofer louder, but there's no increase in bass depth relative to frequencies higher up. I'd been largely happy with the passive bass/treble balance, but in active mode, I sometimes preferred to add a bit more treble. For example, on Telephone Line from ELO's 1976 album A New World Record, an increase in high-frequency output of +2 helped greatly. This recording is a bit congested, so raising the tweeter level made a worthwhile difference.

Returning to classical, and Mahler's 5th Symphony (a live performance at the 2004 Lucerne Festival with Claudio Abbado conducting) proved enlightening and demonstrated the benefits of going active in terms of dynamic range. The recording is extremely impressive, but miking is quite close. The added clarity afforded by active almost made it feel like you were listening from the conductor's rostrum. Cellos and basses exhibited a surging, electrifying presence and seemed to leap out from the speakers.

I was playing at slightly higher levels, with peaks reaching around 73dB. Towards the end of the work, things expanded impressively to hit 77dB. Wow! Musically, the whole experience was exhilarating and involving. Returning to passive was like moving fifteen rows back in the hall. The music still sounded vivid, but wasn't quite so focused or visceral. Climaxes didn't boil and surge with the same angry intensity as they had in active mode. Conversely, passive felt a tad more relaxed and comfortable. At times, active was almost too intense.

The AL6 active crossover's adjustments can also help make low-volume listening more satisfying by allowing the high frequencies to be raised. Being so efficient, the La Scala is naturally fast and dynamic; however, the ear's sensitivity to high frequencies decreases as volume levels are lowered. When listening at lowish levels, lifting the tweeter volume to (say) +3 or higher will give the sound added presence, making it sound clearer.

If I owned a pair of AL6s myself, I'd be perfectly content to use them passively. They sound great that way. At the same time, I'd be mulling over a future upgrade to active, which is definitely a step forward, delivering much-enhanced performance. However, as hinted at earlier, distance lends enchantment with horns. If you can sit 20 feet back from the AL6, you'll achieve a more integrated and homogeneous result with fuller, deeper bass. Sitting closer is also possible, but may be something of a mixed blessing.

Horn speakers are naturally assertive, and the output from a horn-loaded midrange and tweeter is penetrating and intense. Sat 20 feet or so back, I like my Cornwall IVs very much. However, when sitting at my writing desk - about 6 feet away – they're a tad forceful. Of course, it's all a matter of personal taste, as everyone's hearing varies. Some listeners like a front-row seat – others prefer to sit further back. Just remember that active delivers extra focus and clarity, plus increased dynamic attack, which enhances the natural immediacy of horns.

The Musical Fidelity M6s/M6x 250 pre/power amplifier, which I used for active, while not as refined and sophisticated as the Synthesis Titan 100, performed extremely well. Indeed, on balance, it sounded better than the passive option, despite the tube amp's superiority. However, it's essential to choose an amplifier with low residual hiss or hum. The Synthesis T100 was effectively silent, but the MF combination produced a faint hiss, even at the minimum volume setting. The super-high sensitivity of the AL6 reveals this sort of thing.

The Verdict

Updating a classic is always risky, but Klipsch designer Roy Delgado has done a fantastic job with the new AL6. He has enhanced all the many virtues of La Scala while reducing its flaws and limitations. It doesn't necessarily equal high-end speakers specifically optimised for near-field listening, but for those with large listening spaces, this speaker's ability to create a huge sound from a tiny amount of power is nigh-on unbeatable. And if loud is your thing, the new La Scala can produce SPLs of 120dB with extremely low distortion. Equally, it can be played quietly and still deliver results that sound solid and focused.

Hugely versatile, this speaker plays a wide range of music brilliantly. Speaking as a classical music guy, the lack of colouration and musical articulacy makes it unrivalled on unamplified human voice and natural acoustic instruments. Yet it is equally suited to jazz and loud rock. So, this new Klipsch is great value, considering it offers sound comparable to speakers at up to five times the price in the right room, especially in active mode. So if you're lucky enough to have the money and the floor space, then it's an absolutely essential audition.

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