Press

Reviews

Youtube video available from the Hifideluxe Munich 2016. Published by the platform AV Showrooms.

2018
twitteringmachines.com

Article in “twitteringmachines.com” about the Custom & Subway on the Capital Audiofest 2018:

“Canada’s VK Music went the opposite direction, showing the Elekit TU-8600 300B SE Tube Amplifier Kit ($1,185 with0ut tubes) semi-nude. I have a soft spot for 300B tube amp kits and the scuttlebutt about town, not Rockville, is this little number is worth a longer listen (Herb Reichert has one in for review over at Stereophile where my friend Art Dudley talks about how he was also impressed by this room). The Elekit TU-8600 was driving a pair of these AER-based see-through horns and the sound was delicate, intimate, and inviting.”

Go to Custom
2018
Enjoythemusic.com

Article about Charney Audio Companion Moderno with BD3 in on the Capital Audiofest Show 2018

“I’m typically not taken by single-driver systems, and while this one was still subject to the shortcomings that prevent me from really falling for such systems (limitations in extension and dynamic expressiveness), what this system conveyed in terms of its stunning immediacy, warm, vibrant tone and almost corporal texture, all while creating a reach-out-and-touch sense of body, was very alluring.”

Go to BD full range driver
2018
Enjoythemusic.com

Article in “Enjoythemusic.com” about the Custom & Subway on the Capital Audiofest 2018:

“While I’m not much of a fan of single driver speakers, this modest system just did so very much right! It really lit up with incredibly delicate intonation of male vocals, strings, and brass, affording nice sparkle to piano. Even with its slight overall limitation at both extremes, this system managed to make music in this smallish room, with slightly limited staging and image cues.”

Go to Custom
2018
Stereophile

Article about the Custom & Subway on the Capital Audiofest Show 2018

“An assembled TU-8600 sounded amazing driving a pair of AER twin-paper-cone, full-range drivers in shallow, cleverly made Plexiglas horns (3900 Euros/pair for the drivers, 3200 Euros/pair for the enclosures). Judging from the smooth, wide-range, and altogether non-problematic sound I heard from those 106dB-sensitive, easy-to-drive (16 ohm) German-made loudspeakers, I can only conclude that the best Lowther-like drivers are no longer made by Lowther—far from it.”

Go to Custom
2013
Stereophile

Article in the english stereophile about the AXJET horn loudspeaker by Fred Davis, which is equipped with the AER BD 2 B (MD 2 B). It is a review of the front and backloaded horn with the Audiovolver Room Correction System from Paul Messenger.

“My test gear […] confirmed the Axjet´s very high sensitivity: mostly above 96dB, peaking at around 103dB. […] my experience of the Axjet persuaded me that a high-sensitivity, single-driver, compound-horn loudspeaker does have inherent dynamic advantages over both conventional direct-radiator an even back-horn designs. Its ability to nail the dynamic window and contrasts of a recording was so utterly convincing that it established an envaible standard.”

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2013
Sixmoons

Article about our drive unit AER BD 3 B (MD 3 B) in the onlinemagazine sixmoons. On the page are also the Greek Arcadian Audio Pnoe horns equipped with AER drivers:

“We were quite happy with the upgrade Filip Keller had performed on our new MD 3B wideband drivers. There now was increased sensitivity and both extremes of the frequency spectrum had gained extension from strongly reduced self interference. Even at low levels the full spectrum and impact were there and we spun record after record to our full satisfaction.”

Go to BD driver
2011
Sixmoons

Article by sixmoons about the speaker Greek Arcadian Audio Pnoe, equipped with BD3B (MD 3 B). The pnoe is a very long backloaded horn:

“Many available drivers already found their way into various commercial or DIY single-driver horn designs. Lowther is one of them and popular. Arcadian Audio however did not choose Lowther but after many listening sessions selected the German AER MD3B driver. In combination with the particular horn materials the Pnoe champions this particular driver matched best musically and electronically. In combination with the hornloading the driver performs at 100dB sensitivity and presents an amplifier-friendly 16 Ohms load.”

Go to Axjet
2008
HiFi Tunes

Article on the high-end do-it-yourself system built by Mr. W. from E. published in HiFi Tunes’ equipment book in 2008.  Mr. E. has equipped his front-loaded horns with an AER driver, and there is hardly anything left that makes you think of the usual do-it-yourself concepts.

Excerpt: ‘The Onken performs smoothly and precisely up to 150 Hz.  Beyond that, the job is done in a phase-corrected arrangement by another specialty that – which comes as no surprise – is the master’s work, as well: a round Traktrix horn made of carbon fibre with a beautiful red coating, powered by the well-known “super loud” drivers of driver specialist Filip Keller.  This combo, as commented by the host, reached up to 20 kilohertz in a smooth and linear way.  So, you have every right to speak of a full range driver concept with bass support.’

Go to BD Driver
2008
Image HiFi

Article on the Rawi Sonic Ecolution 1 satellite/subwoofer system published in 2008 by Image HiFi.  The satellites feature AER full range drivers with a transmission line, whilst the AER studio bass has been installed in the subwoofer.

Excerpt: ‘Virtually every efficiency and broadband fan knows Filip Keller and his company AER.  The almost insanely designed drivers – they can hardly be described any other way – of the Stuttgart loudspeaker specialist rank among the top of what is possible and feasible today.  That is why – I better come straight to the point – they are quite pricey.’

Go to BD driver
2007
HiFi Tunes

Article on the Stereofonie Erda two-way dipole speaker published in HiFi Tunes’s speaker book.  The test report’s motto: ‘Monster bass and extreme full range drivers jointly go about the music.’  That is what happens when a 46 cm JBL subwoofer driver and a 20 cm AER full range driver meet.

Excerpt: ‘The man turns out to be Filip Keller, who, among horn and top efficiency fans, enjoys an almost legendary reputation of total thoroughgoingness and offers sinfully expensive, extreme full range drivers under the acronym AER.  Wouldn’t such a 102 decibels driver be the ideal access to a whole new league, Mr Zirker?  After all, high efficiency and seamless playback as a matter of principle have never hurt anyone…’

Go to BD driver
2006
Sixmoons

Article about the Lamhorn 1.8 loudspeaker by RL Acoustique in the onlinemagazin sixmoons. The backloaded horn is powered by AER driver and has also been developed by Robert Lamarre.

“As for the differences with drivers, the AER has the least amount of cone coloration. The Reps are second and the Lowthers — with the new whizzer cone introduced a few years ago — a close third. Where the AER marks a clear difference is in the 2.5 to 4kHz region. It has no peak at all. The others do. To some, the upper midrange peak in the presence region is fine while others find it objectionable. I must admit my favorite driver is the AER MK1 […]. I should add that because I use Tenor amps myself which are ruthlessly revealing, the MK1s are the best bet. It really is a question of system matching and taste. Robert Lamarre”

Go to BD driver
2004
LP

Article on the Ayon Raptor published in LP.  The Ayon Raptor is a two-way box equipped with AER full range drivers and two bass drivers taking over from 150 Hz in the low-frequency range.  Thanks to the low-frequency separation, the broadband point source is maintained.  Thus, the speaker basically creates a self-contained FAST system.

Excerpt: ‘At first glance, the Keller full range driver might look like one of the well-known Fostex or Lowther designs.  However, that is not the case […].  With AER Loudspeakers, his small company based in the Stuttgart area, he manufactures full range drivers close to the limits of what is possible – also those for the Ayon Raptor.’

Go to BD driver
2004
Image HiFi

Article on the Opera Audio Unicor Mk II back-loaded horn speaker published in Image Hifi in 2004.  Excerpt: ‘Those who want to enjoy the best efficiency possible should consult a professional…and this professional is without a doubt Filip Keller.’

Excerpt: ‘When working as a team, horn speaker sound distribution and driver realise as much as 102 decibels per watt and meter, depending on the metrological interpretation.  In serious cases, even 1 watt power amplifiers would come within the reach of users; any hardcore tube amp freak able to handle a soldering iron would happily see an opportunity to operate exotic low-power circuits.’

Go to BD driver
2003
Image HiFi

Image HiFi about the Ayon Dragon and Opera Audio Opera TL speakers, both equipped with AER drivers.  Excerpt: ‘Leaving pure doctrine and purism aside, the Ayon Dragon is, apart from being extravagantly designed, an extraordinary, phonetic piece of engineering art thanks to cleverly applied pragmatism.’

Excerpt: ‘AER drivers are developed by Filip Keller, whose company enjoys an extremely good reputation among the entire full range driver crowd.  The driver used in the Opera features an inverse crimp, a featherweight paper membrane the wall thickness of which increases towards the exterior.  Naturally, it comes with an extremely powerful drive.’

Go to BD driver
2001
Image HiFi

In 2001, the Image HiFi magazine tested the legendary Audiovector in the Opera Audio version.  It is the first time for the Audiovector to be listened to with AER speakers.  Each box uses two of them.

Excerpt: ‘Our test model, however, is not equipped with English parts, but with drivers made by the Stuttgart manufacturer AER.  As revealed by the “Opera” appendix, they have been developed exclusively for Opera Audio […] The result is impressive, measurable and, above all, absolutely worth listening to.  The handmade AER full range drivers are in line with delicately designed instrument making and transmit signals well beyond 20 kilohertz without any noteworthy breakdown in amplitude and phase.’

Go to BD driver