Mike Lenehan Interview
Based on the Gold Coast in Australia, Lenehan Audio has enjoyed a loyal following from many StereoNET readers recently. In this recent interview, we learn that Mike Lenehan's single aim in audio reproduction is 'accuracy'. Read on for a great insight to Mike Lenehan and his fine products.
Q : Could you tell us about your background and how you came to start Lenehan Audio?
In 1969 my brother Russell and I walked into Harvey’s Sound in Surfers Paradise and saw a pair of JBL L55 Jubal Loudspeakers driven by a Sonab integrated amplifier and a turntable. We listened and were captivated . I think it was Henry Mancini playing on that turntable. That was the day we started. Within five years I was building and selling speakers for money only because I had too many and mum said they must go. Lenehan Audio was officially trading though as an entity from 1994.
Q : What type of music do you prefer to listen to. I guess as a small manufacturer your business takes up a lot of time. Do you get much of a chance to enjoy any live music?
Classical, Jazz, R & B, and everything else. I love Dire Straits, Rage Against the Machine and Faithless. Without live music you can forget fidelity. Fidelity to what? I am a member of the Friends of Music and attend everything that is available on the Gold Coast and as much as I can get to in Brisbane. The Gold Coast Philharmonic practice sessions are savored.
Q : Are there any other HiFi manufacturers or people in the industry you admire?
The two that come to mind are George Short from North Creek Music Systems and Vince Bruzzesse from Totem Audio. Both these designers are in my mind near the absolute edge of current loudspeaker design. Although associates in the Lenehan Audio team are currently involved in valve and digital design my knowledge of electronics and digital design is a little too scanty to comment with any relevance on other industry areas.
Q : You sell a single model loudspeaker. It is a small two way standmount design. Is there a reason why you have concentrated on this one loudspeakers design especially when there are so many other highly regarded, superficially similar loudspeakers available. What do you see as the advantages and disadvantages of your chosen loudspeaker format?
I’ve only currently got one model, the ML1, because the little beggar has become a rod for my own back. I have been developing the ML2 and ML3 for 3 years now and up until recently they were still being beaten by the ML1. We are now very close to having a loudspeaker range though (fingers and everything else crossed).
Basically I do not see the ML1 as occupying a niche in the market, but more as a device that makes music. I am terrified of releasing other devices just because they play louder or make more bass etc, etc. I do have one very understanding customer who has placed a deposit and been waiting nearly two years for his ML3’s.
Q: Your web site has a lot of interesting information and possibly controversial statements. You say: in a single word “accuracy”. I think many people associate “accuracy” with measurements. Can you explain what you mean when you use this word and how you determine if a loudspeaker is accurate or not?
Accuracy and musicality are one in the same. If you sit in front of a live string quartet, maybe at three meters and in a decent acoustic, would you call that accurate or musical sound? Neither of course and both of course. I’m not about to lose the word accurate just because some jaded audiophiles equate it with edgy digital bipolar bright sound.
Trying to determine what is accurate is in fact asking a question that is absolute and no matter how convinced I may be that I’m correct the fact is the question is insoluble and moot. Should a reproducing system reproduces warts and all what’s fed to it’s inputs or should it take those 16bits and 44.1khz signals and interpolate them within it’s bowels and spit out a sound that sounds like a real piano?
My loudspeakers are designed in such a way that when they are partnered with current state of the art ancillaries the sound that eminates from them is as close as possible to what I hear when I listen to live acoustical unamplified musical instruments and voices.
Q: What parts do measuring and listening play in your design and development process. Has the availability of relatively inexpensive computer based design optimisation and measurement gear made life easier for small manufacturers?
I use a Clio MLS measurement system and without it my loudspeakers would be rubbish, no question. I have an extremely intimate working relationship with this instrument. I use the old DOS based software and dislike the new windows software. At the same time I can report a significant dislike for software based loudspeaker design programs. They basically lean too heavily on IQ based design decisions in my view instead of my preferred EQ (Emotional Quotient) based mental processes.
The difference between a small manufacturer and a big manufacturer is that the big manufacturer has more money. If I had a zillion bucks the money would have to wait outside in a bin till I walked out the door with the finished design.
Q: How important is the quality of the loudspeakers, compared to other components, in determining the overall quality of a sound system?
The quality of a system depends on everything of course and this is not a cop out. An F1 car wouldn’t win a race without a driver in it but it also wouldn’t win if the rear rebound damping was set three percent too hard.
OK, I cant stand it, it is the speakers that are the most important! I could take a pair of ML1 Plus R and drive them with a NAD 326BEE integrated amplifier and a cheap CD player, tie it all together with lamp chord and Crazy Clarks interconnects and I know I could listen to it all night. On the other hand if I had $ 150,000 worth of front end and the right cables the sound driving a pair of $500 mini monitors would possibly make me want to vomit in the wastepaper basket.
Q: Which parts of your loudspeakers are made in house?
We buy in the drivers, capacitors and resistors. Spray painting and cabinet CNC work (but not assembly) are contracted out. Everything else is made in-house including winding our own inductors.
Q : You say that the crossover is the heart of any loudspeaker. What is the design process for your crossover and how important are the specific topology and the nature of the individual components used in the crossover. Do you have an opinion on the relative merits of passive and active crossovers?
Crossover topology is extremely important. We mainly use Linkwitz Riley style filters because of their sharp antiphase nulling features. A low frequency and high frequency driver must track in very accurate phase together well outside their passbands. Achieving accurate phase and amplitude performance at the same time can cause me at times to descend into something akin to a coma , very often emerging after all this effort with a total failure. At this juncture I’m liable to walk over to the system and just listen to music until I have another bright circuit idea which can very easily be doomed to failure as well.
The problem with loudspeaker crossover design is having to serve two masters at once: the physical world, i.e. gravity, inertia, acoustics, and energy storage; and the electronic world, i.e. capacitance, inductance, and thermals.
I get crossover circuit ideas with my eyes closed at night and acoustical ideas with eyes open. This is getting weird!
The crossover design process begins with setting what I call the bass room integration hinge. The room boost or Haas curve begins boosting the bass from about 120hz down so this must be very carefully considered. Simply put you need to look at how loud a given bass driver can play at the lowest frequency you wish that driver to reproduce in the target room and of course at the preferred listening distance. After you’ve established this, the rest of the frequency range is hinged off that point.
I believe that passive crossovers are superior. As soon as you start using real inductors, i.e. very large low DCR aircored types, losses become very low. Compression and saturation just does not happen. I know I’m going to get in a lot of trouble for this but the best most accurate loudspeakers are passive. It is possible for an active crossover to be superior in theory but you would need to have the loudspeaker and active crossover designed exclusively for each other with very accurate phase and amplitude correction. Digital systems also seem to be not yet developed enough to compete. I would be happy to overturn this opinion if I heard an active system that worked but that
hasn’t happened yet.
Q: You use a single pair of binding posts on your speakers. Does this indicate you hear no advantage for bi-wiring or even passive bi-amplification?
With a true bi-wire crossover, by that I mean full star grounding and star driving, there can be an advantage. The problem as I see it is that few crossovers are implemented with high integrity no compromise construction. I’ve looked inside three $4000 to $6000 mini-monitors in the last 3 years and found what I can honestly describe as junk masquerading as crossovers. One of them had a wholesale parts cost count of $13.20 for the pair. The cheapest ML1 crossover we build costs us wholesale $148 in parts and six hours labour to build one pair. So tell me why would you buy two pairs of nice loudspeaker cables to biwire your $4000 minimonitors when the crossovers look like they came wrapped in a plastic bag in a Kelloggs Corn Flakes packet.
Q: You talk about your crossovers being “power response corrected” and say that you believe that much of some peoples problem with the sound of digital sources is due to problems in the off axis response of many loudspeakers interacting badly with the rooms they are used in. Could you explain this a little more?
If the ML1 has been received well it is not because of the good crossover, massy rigid enclosure or build quality. It can be explained with one acronym: PRC, or Power Response Correction .
Before PRC we were building the ML1 the same way as now but at best it was only competitive with other good monitors. When you sit in front of a loudspeaker and listen to it only part of what you hear comes straight to you from the drivers. Much of the sound is reflected from the first reflection point, the floor, the second reflection points, side walls and ceiling, and the third re-reflection point, the rear wall. OK here’s the thing: the walls have ears and they are listening to the speakers too. If the off axis sound is edgy and a bit funny then the walls will hear only the edgy stuff and that’s what they will reflect back to your ears.
You may ask why the off axis response of a loudspeaker is edgy and although a full explanation is not possible here there are some easy to quantify basics. On axis the bass driver is flat but off axis it isn’t. Likewise on axis the tweeter is flat but it is also wobbly off axis. The main culprit here is called the off axis tweeter flare. Two other manufacturers I have noted have an understanding of these interactions but to my mind they are rudimentary. The ML1 actually returns a better step response 45 degrees off axis than it does on axis and remains phase coherent even 60 degrees off axis.
The walls hear the nice smooth tonal balance that you hear so their reflections wont scratch on your ears like fingernails on a blackboard.
Q : Some designers believe that loudspeakers should be linear phase and / or time coherent and go considerable lengths in terms of crossover design and cabinet construction in an attempt to achieve this. What is your opinion on this?
Oh, oh. I’m going to get in trouble here. I’m steeling myself right now and taking a big breath. Time coherent loudspeakers are virtually indistinguishable from their non time coherent bretheren. What is called correctly ZDP or zero delay plane integration is a waste of time. Why is that? The problem with correctly ascertaining whether a time coherent loudspeaker sounds better or worse than a non time coherent one is that they are different loudspeakers in the first place. To nut this out properly you would need to:
1. Have a well designed loudspeaker enclosure that positioned it’s drivers in an accurate ZDP
2. Ensure that the chosen drivers had very usable excursion and low distortion levels nearly two octaves outside their passbands.
3. Be able to design and implement effective electrical domain equalisation shunting circuits to help the drivers with the arduous hiding they are about to receive. You must also ensure that these circuits don’t affect the ability of the loudspeaker to return a time coherent waveform.
4. You must then tune it very finely so that it has the correct amplitude response and ensure it returns a very cohesive step response. Even the thickness of the tweeter gasket will effect the time cohesion.
I have actually built this loudspeaker and to a tolerance that you are not going to get from a very expensive off the shelf design. It uses a Morel MW168 bass driver and MDT37 tweeter and it took me 5 months from start to finish. My design book shows a total of 331 hours time between March 2001 and July 2001.
What did it sound like? Not bad, quite nice in fact but I just couldn’t do the things I wished to do with the design as the medium simply didn’t allow me the licence to make that thing dance.
So I dropped the 1st order time coherent crossover and designed a quasi 3rd order filter which crossed at 2khz. The drivers natural roll out combined with the electrical filter topology to effect a fourth order acoustic result. Now the speaker measured with very low distortion both harmonic and intermodulation because the tweeter wasn’t jumping back and forward like a randy silky terrier on a visitors leg. Likewise the bass driver wasn’t exposing it’s cone breakup mode at 5khz.
The sound was now fluid, dimensional, fast, and the bass, no comparison. That was the day time coherent loudspeakers were out of time for me.
Q: Many people looking at your speaker would probably think they would like to use them with subwoofer(s ). How do you feel about this?
The ML1 is designed for a specific room size and volume, that is 7 metres long by 4.5 metres wide by 2.8 metres high which is 88 cubic metres. The ML1 will command a room like this without a subwoofer as long as you don’t want to play the rare disc that has bass below 40hz and wish to play that disc above an average level of 83db in the listening chair. If you do you may need a subwoofer.
Subs are difficult to integrate and they don’t care where you want them to be as they will work only where they want to work. You can forget the WAF integration. All said and done you could need a bigger speaker. We do supply ML1 subs but they require significant consultation usually to make them work and that burns my time up.
Q : Your speaker uses a rear facing port. What do you see as the pros and cons of front vs rear facing ports and sealed vs ported boxes ?
Aww come on, you’re asking me all these monster questions. Sealed verses vented, that’s a whole book there!
Front ports are basically old fashioned. The big problem with them is they cant be too large because midrange will come out of them. It’ll just hitch a ride with the normal port action so you have to have a non linear vent if you have it on the front. If you keep the port small in diameter it means the only frequencies that can come out of it are a function of it’s diameter and the corresponding frequency wavelength. Small vents don’t let too many midrange and resonance problems effect the wideband sound the speaker is trying to reproduce. The problem with small vents is that they begin to register increased pressure with high drive levels which means they are non linear. So rear firing is the go. The ML3 uses a monster port nearly 100mm in diameter and 500mm long but it’s underneath the speaker firing at the carpet.
A sealed enclosure is technically as perfect as you can get with .5 Qtc being considered transient perfect. John Dunlavy’s alignment preference was for around .6 Qtc I believe. Our subs which are always sealed run at .64 Qtc. Q is quality factor with the lower the number the tighter or more damped the bass and the higher the number the looser the bass or less damped it sounds.
What we use in our ML1, 2 and 3 is a proprietary alignment and tuning which emulates the best virtues of sealed (tight, fast ,articulated ) with the weight and extension of vented. You will never hear one of our loudspeakers boom in the bass.
Q: Audiophiles like to talk about tight/fast/deep bass as a very important ingredient of good sound. Some people believe that the bass quality of a speaker is almost completely determined by its position in a room and the nature of that room. How much importance would you place on the characteristics of the speaker itself versus the influence of the room?
I sell speakers so I would love to say it was mainly the speakers on this one but the room and where the speaker is placed is very important. Where a designer hinges the bass into the room determines what kind of interaction that room will have with the speaker. If I wanted the ML1 to play flat to 28hz in an 88cubic metre room I could do that it’s just that the speaker would be only 73db sensitive and only be able to play 85db peaks with about 1000 watts in (the ML1 will handle 1000 Watt peaks). The speaker still has a bigger influence on bass quality I think but the room is capable of significant influence.
Q: You say that the use of custom drivers is overrated. Your speakers appear to use good quality but not premium priced drivers. You say you are not interested in using a specific driver or type just because it’s the latest thing. What qualities do you look for in drivers? Do you modify the drivers you use?
Oh, good question . Modern drivers are excellent and you can buy them cheaply because they can be effectively mass produced on a line. Drivers must be very carefully selected but not for quality only for application. We will be modifying some of the drivers in future models but normally there is no need.
I know your average audiophile will prefer say a Scanspeak tweeter to a Peerless but this is simply due to marketing. They are both very good of course but you could give me the best paint, the finest canvas and brushes but I’m not going to produce a Mona Lisa for you no matter how hard I try.
Overwhelmingly it is the crossover network that determines the sound you hear. You could take a retail $12 tweeter and $20 woofer drop them in a 12mm MDF box with very cheap electrolytic capacitors resistors and inductors and if those bits were phase and amplitude correct the sound would be surprisingly good.
Overall I would consider the component pecking order to be from most to least important to be thus: 1. crossover, 2. enclosure, 3. drivers (woofer, tweeter), 4. internal dampening materials and wiring.
Q: Your reference system includes valve amplifiers. Do you favour the use of valve amplifiers with your speakers?
We use valves almost exclusively in source components ie. preamplifiers and DAC’s At the moment we are using solid state for power amplifiers which produces and an excellent balance of liquidity and punch.
Q: Your web site says that your loudspeakers are designed from first principles using hardnosed electrical and acoustical engineering. I think some people might then be surprised at your support for things like “exotic“ cables, cable burn in, special binding posts, and expensive passive components in crossovers. How did you come to the view that these are important to sound quality?
Ah ha, good point. Yes indeed I know for instance that many people say there is no such thing as cable burn in. Well there is. Sorry about that but anyone that says there isn’t will soon have egg on their face. The ML1’s for instance take 350hours before they are fully up to speed and I’m afraid that’s a fact. Those that say there isn’t are simply in denial. Unfortunately these naysayers will never put themselves in a position where it can be proved to them, that way they can hang onto their draconian views.
We had a customer arrive at the factory proclaiming he had never heard any difference between cables and directly asked if I could prove my claims to him. Not only did he immediately hear the significant improvement but his sister who is not an audiophile heard it immediately. He bought the cables.
Conversely another audiophile I know sits in front of the same comparison and after I say “did you hear an improvement?” He says “Ah well not sure, maybe, ah… not really… can you play it again?” or he seems to require hours of listening then says “I can hear a difference but how would you know it’s better?”. Who knows what he’s hearing. Not much apparently. Some people can’t hear it and I think it may slightly upset them internally so psychologically it’s safer to say it doesn’t exist .
Q : Most HiFi manufacturers and retailers seem pretty hard hit by a declining interest in audio in general and by the effects of the GFC in particular. What special qualities do Lenehan loudspeakers have that will help you survive in a very competitive marketplace and what can we expect from Lenehan audio in future?
We are very fortunate. The cables are flying and I have just put a dedicated cable builder on two weeks ago to supplement Ben who can only spend half his time on them. In the future we will have a range of models with the ML1’s , ML2’s and soon to released ML3’s.
We have seven pairs of ML1 and three pairs of ML3’s on back order now all with three week waiting times. Strictly speaking we are not manufacturers we are builders and we build to order. I think we are catching many sales that would otherwise have gone to some defunct highend dealer. I think some audiophiles who would otherwise have purchased a $15,000 speaker in a better economic environment are now selectively filtering down to us. Our prices are deliberately being kept low as I just don’t think people have the liquidity they once had.
Many thanks for your time, Mike. Best of luck with the future.
Lenehan Audio Website: www.lenehanaudio.com.au