Northward Acoustics - Images of our daily lives designing and building studios around the world in 2016.
This text provides the foundation material for solving problems in vibroacoustics. These include the prediction of structural vibration levels and sound pressure levels in enclosed spaces resulting from known force or acoustic pressure excitations and the prediction of sound levels radiated by vibrating structures. The book also provides an excellent theoretical basis for understanding the processes involved in software that predicts structural vibration levels and structural sound radiation resulting from force excitation of the structure, as well as sound levels in enclosed spaces resulting from vibration of part of the enclosing structure or resulting from acoustic sources within the enclosure. The book is written in an easy to understand style with detailed explanations of important concepts. It begins with fundamental concepts in vibroacoustics and provides a framework for problem solution in both low and high frequency ranges. It forms a primer for students, and for those already well versed in vibroacoustics, the book provides an extremely useful reference. It offers a unified treatment of both acoustics and vibration fundamentals to provide a basis for solving problems involving structural vibration, sound radiation from vibrating structures, sound in enclosed spaces, and propagation of sound and vibration. | Author: Colin H. Hansen | Publisher: CRC Press | Publication Date: Mar 06, 2018 | Number of Pages: 360 pages | Language: English | Binding: Paperback | ISBN-10: 1138093815 | ISBN-13: 9781138093812
(Full Article) Diffusion in audio is often a misunderstood concept. We set to demystify common myths and explain the reason to buy a good diffusor, as it not only changes the reflections to propagate in different directions, but does so EVENLY in all directions. Just splitting a wave to go into 2 directions doesn’t do enough. In audio, Diffusors are used to treat sound imperfections such as echoes and are an excellent complement to sound absorption because they do not remove sound energy.
Learn the basics of diffusions, including the effects it has on your studio setup, then get to work building your own acoustic diffuser!
Retractable Acoustic Curtains are used in industrial applications for the purpose of reducing noise in a manufacturing facility. Use as an enclosure, curtain walls or panels.
Advanced Acoustics 100mm Mel-Acoustic Slab Acoustic Foam Treatment Panel 600mm x 1200mm What's In The Box? The 100mm Mel-Acoustic Slab Panel is sold individually. Each acoustic panel is sized 600mm by 1200mm and is 100mm thick. One acoustic panel will cover an area of 0.72sqm. The acoustic panels are precision cut and on average will absorb 90% of the sound waves.The colour of these studio foam sound deadening panels is white. What Are The Benefits? The Mel-Acoustic Slab is a very versatile panel. These panels can be easily trimmed and cut to size with a sharp knife. They can be used for building custom enclosures or they can be wrapped in your own open weave cloth to make your own acoustic panels or simply left as they are and mounted to the wall or ceiling. By installing these acoustic panels in the room at first reflection points or at other key areas you will increase acoustic clarity and remove unwanted distortion. These acoustic panels work hard at controlling mid to high frequencies to help remove echo and control reverberation. These panels can also be used in conjunction with our other acoustic panels to create a unique design. Care is taken in optimising size, profile, foam cell structure and foam density to present a product that offers high visual and acoustic value. Durability is high on our list of priorities too, we manufacture a foam that won't crumble and turn to dust and won't change colour as soon as you've mounted them to the wall or ceiling.The properties of Melamine Acoustic foam means it is light but offers incredible performance considering it's weight. Also the white panels will stay white and can easily be cleaned if they do become marked. The bottom line is that the Mel-Acoustic Slab Acoustic Panels will assist both you and your room in working to it's full potential. Where Can I Use Them? There are a wide range of applications for our acoustic products including:High End Professional StudiosHome StudiosRehearsal RoomsHome CinemasDedicated Listening RoomsPublic BuildingsProfessional and Home OfficesServer RoomsCustom EnclosuresAnd more What Are The Technical Details? Product NameMel-Acoustic 100mm Slab Panel 600x1200Product Size600mm x 1200mmPanels Per Box1Area Covered Per Panel0.72sqmProduct Thickness100mmNoise Reduction Coefficient (NRC)0.90Sound Absorption ClassAProduct ColourWhiteProduct WeightFire ClassificationDIN 4102 - B1FMVSS 302 - FulfilledBS 476, part 6 & 7 - Class 0UL94 - V-O, HF-1EN13501-1Chemical ResistanceResistant to hydrolysis, alcohols, hydrocarbons, most organic solvents and dilute acids & bases.Foam Density16kg/m3Tensile Strength120kPaHardness40% deformation : 7-20kPaCompression Set50% at 70øC for 22 hours : 10%-20%Cell Count130-200 ppi approxThermal ConductivityC0.035W/mK @ 10øCContinuous Service Temperature150øCToxicityDIN 4102 Class A2
WhisperRoom manufactures and ships Sound Isolation Enclosures around the world. Learn how we can help you reduce sound to a whisper.
One of the most intriguing speaker enclosure out there is the transmission line speaker design. A lot of tinkering awaits for the average DIY
P2P Technology Q Acoustics P2P bracing has been implemented throughout the entire 3000i Series and works to support the areas in the enclosure that...
Biologists have long been curious to know whether giraffes produce any substantial sounds. Audio recordings from three giraffe houses in European zoos suggest they do
SME tonearm tonarm conversion kit vintage tube amplifier DHT vintage Tannoy speaker speakers enclosures cabinets, horn, baffle, western electric
Techno Acoustic Wooden Slats Introducing Techno Acoustic Wooden Slats, Manufactured for the first time in India A make in India initiative by Techno Acoustics These are aesthetically appealing, high performance and durable sound absorptive wall panels. Larger than the conventional panel, this versatile variant envelops areas and provides acoustic enclosures without the feeling of confinement. […]
Embrace a blend of vintage charm and modern technology with the Retro Radio Soundbox Bluetooth. This compact device, housed in an acoustically tuned wooden cabinet, brings both style and impressive sound quality to any room. It's a nostalgic nod to the 60s and 70s, infused with today's audio tech. COMPACT DESIGN & PORTABILITY – The Retro Soundbox's small stature, measuring just 116x65x73.5 mm and weighing 385g, makes it incredibly portable. Its classic 1960s and 70s design, combined with modern functionality, lets you carry a piece of history wherever you go. EXTENSIVE PLAYTIME – With a powerful 3.6V/2600mAh rechargeable battery, enjoy up to 36 hours of playtime. Whether at home or on the go, your music keeps playing all day and night without the hassle of frequent charging. BLUETOOTH CONNECTIVITY – Seamlessly connect to any Bluetooth-enabled device for wireless audio streaming. Effortlessly play external playlists from Spotify, iTunes, or Google Play, making it your versatile music hub. SUPERIOR SOUND QUALITY – Experience amazing sound from its loudspeaker, housed in an acoustically optimized wooden case. This retro radio doesn’t just look good; it sounds incredible, offering a rich audio experience that belies its size. VERSATILE MEDIA OPTIONS – Besides Bluetooth, the Soundbox features an AUX-In port and an FM tuner, providing multiple ways to enjoy your music. Whether it's streaming or tuning into your favorite FM station, this radio has got you covered. The Retro Radio Soundbox Bluetooth is more than just a speaker; it's a timeless piece that unites classic design with modern audio technology. Perfect for those who appreciate vintage aesthetics and quality sound. Add a touch of retro elegance to your space – get your Retro Soundbox today!
TAD TSM2, TAD 2402, TAD 2401, TAD TD-2001, TAD TD-4001, TAD TL-1601, TAD TH-4001, TAD TN2, Exclusive Pioneer, Jazz Kissa, Sunshipaudio,
Come realizzare un sistema di ricambio aria per sala prove, studio di registrazione in modo che sia adeguatamente isolato
In the last couple of month I have tried to find a solution for the incomparable 15'' Tannoy driver to be used in a sort of universal enclosure. I concentrated on two nested main questions, the best possible response coming from a living room friendly sized cabinet. My main aim in this process was, independant from any technical design principle (i.e. reflex, open baffle, sealed, horn development), to archive a foremost natural tonal response. It is best described as a transformation of the electrical signal into a acoustic representation of music, lacking any typical electrical significance or sort of common compressions arising. My ideal response is orientated as close as possible to live performances of small scale chamber music or small jazz ensembles in limited scaled room conditions. Here the acoustical resonant corpus of the performing instruments (i.e. cello, brass horns, piano, etc.) is quite similiar to the resonant corpus of the performing transducers (loudspeakers). My definition and further undertakings can be understood by the most of yours within this model in mind. Typical Tannoy Lancaster cabinet (sealed version for the 12'' driver), these generation cabinets are well made from lumber core plywood, excellent material. Some month ago at the beginning of the design process I did not know, with what sort of cabinet I will come out at the end. I did play through in my mind many possibilties, a combined back/front loaded horn design, a vented port cabinet with 200 liters volume or even a bigger sealed enclosure, working as a resonant chamber. I definetly wanted to leave behind the limitations of the common known vintage cabinets. Instead I was very energetic to find new ways to the naturalness arising from a newer understanding of the loudspeaker to be a resonant musical "instrument". In the last decades my understanding of "true fidelity" in conjunction with single audio components has been widened by a general respect of each components resonant properties, where the speakers show the most suggestible influence of all of them as to be the final transducers. There are the well known designs of similar speaker cabinets made in the past: some Altec designs like the VotT-line, the japanese Onkens, JBL, EV, Jensen and some other professional small scale pa-addressed designs for 15'' diaphragm sizes. They all have one thing in common, to be originally designed for a different speaker type in mind than the Tannoy Dual Concentric. The uncomparable design of the Tannoy offers opportunities other speakers don't show and these should be respected to find a perfect matching solution. And finally I did want to share my experiences with other Tannoy addicts, because those don't have a lot of choices of cabinets in our culture (may be in Asia, foremostly in Japan there are options for after market enclosures). Tannoy Amesbury with 15'' Monitor Golds I think nearly 90% of all vintage Tannoy 15'' Dual Concentric speakers are installed in the typical 120 liter volume ported box. In history it all started with corner cabinets for monophonic reproduction, the huge ones were horn designs the smaller acted like vented port enclosures. Both types used the backward radiated energy of the cone to be conducted as a supplementary part to the air. The horn used the flanking walls to extend its development. Bot design principles are made to reduce the inherent limitations for the lower frequency response of a boxes loudspeaker. With the need for stereo pairs, the range of enclosures was expanded to rectangular versions like the GRF, York and the Chatsworth. These could be better placed in the room for a improved stereo illusion. Additionally Tannoy started in the 1950ties a small universal cabinet line to fulfill the needs of their customers to smaller cabinet sizes, used for the 12'' and 15" units simultaneously. This design got widely sold for decades as Lancaster and ended up in the mid 1970ties as strengthened Berkeley of the same size. A vented port in the beginning and a true reflex after Thiele&Small at the end was the most well sold cabinet design for Tannoy of all times. With a size of 85cm height to 52cm width and and a depth of 28cm, the success of this enclosures represents for lots of people already a huge speaker. This size seem to be as well a maximum dimension accepted as a piece of furniture in living rooms from its users. This enclosure limits the performance of a 15'' chassis a lot, in particular with the hard edged versions (Gold, Red and Silver) the backwarded compressed air cushion show a extremely limitation of possible dynamics. A few of us have got luck, their partners do even accept the little bit bigger versions, the Rectangular York, i.e. Amesbury which ended in the late Arden enclosure. With a useful volume of 180 liters, this cabinets support the technical conditions of the chassis much better, but are still more a compromise than a solution for listening pleasure. The hard edged drivers have a theoretical Qt which will lead to a ideal volume of 350 liter for a 30 Hz response with -3 db fall. With this parameters it starts that the speakers are getting almost invisible in acoustic terms and show a good dynamic performance down to a low end with fast transients. The most users cannot accept two wardrobe sized cabinets in their living room in order to match these ideal conditions for the drivers. The biggest enclosure of all vintage Tannoy back loaded horn designs, the Tannoy Autograph Professional with two 15'' drivers in parallel, very poor material choice: chipboard Mr. Ronnie H. Rackham followed another theoretical ideal for optimized sensitivity and improvement in response of loudspeaker cabinets. Horn designs use the backside radiated energy from the cone in order to transmit it through its development to an opening as addition to the complementary other half from the front side. It acts like a mechanical amplifier for the conducted frequencies and adds on the second half of the wave, so the sensitivity will be increased. The very early variants have been designed for the corner position in the room in order to use the flanking walls for the horn extension. Only the GRF Rectangular and the Autograph Professional were made for the plain wall position. The Rectangular was a quite small sized cabinet. Here the ideal horn development (around a lenght of 3 m with a continous opening to 2 x 2 m for 40 Hz) has been cut to be anymore unrecognizable sizes. With a length of 1,50 cm and a opening of 40 x 60 cm the horn acts like a lower middle frequency horn, with a cut off end around 400 Hz. This was my first 15'' Tannoy speaker and I never liked its response. With its hefty frequency belly around 400-500 Hz, this cabinet has set a fundamental dubiousness about horn designs in my very early experience with 15'' Tannoy speakers. Inside the Tannoy Autograph, the complex development of a back loaded corner horn shown at a set of japanese after market copies (plywood). The today operation of the less compromised horn designs (Westminster, Autograph, GRF Professional) makes a dramatically increased acceptance necessary, as to be the speaker a room dominant piece of furniture. Beside the Westminster I do know almost all vintage Tannoy enclosures very well, since I have or had the most of them myself, or some of them are installed at close friends audio set ups. To be honest, not one of the bespoken designs matches my current expectations about a natural sounding music transducer. They all show a unacceptable part in the lower frequencies were folded horn brings a quite uneven response. The positve benefit of all horn designs is the undistorted way the driver can act like in free air resonance, without limiting air cushion and its fast transient response. Ideally I want a performance with realistic and fast dynamic transients, a huge and holographic soundstage, with refined and detailed smooth Hf-response (without any phase shifts and resonant knots), a similiar performance like a natural wooden instrument of comparable size. A horn design at it best comes very close but will be extremely huge and room dominant. The other possibilty to leave the limitations off a boxed speaker is the folded baffle principle. To make it work, it needs a lot of acceptance as new approach of understanding of the role of cabinet (new was meant to be connected with Tannoy speakers – Western Electric and Klangfilm did incorporate such design principles about 70 to 80 years ago). Chinese copies of the Westminster for 12'' and 15" drivers. They do copy everything. I definitely search a solution to use with the superior hard edged chassis from the Monitor Gold, Red or Silver line in conjunction with low power tube amplification. These hard edged drivers need naturally a bigger enclosure to work superior to their later derivates from the HPD line. The limitations of the early cones depend hardly to the physical parameters shown at their low Qt of 0,26, but their sonic advantages are a close mirror of these facts. The nominal 15 ohm (at 1000 Hz) voice coil (Red, Silver and Black) was the preferred VC-impedance when tube amplification was the standard. This impedance matches the plate resistance preference of a pair of tubes and even more of a DHT-Triode better, the different coild at the output transformer to match are only a little help, since impedance shifts over the total frequency spectrum of the speaker can not be covered here. In particular in the lower frequencies the hard edge surrounds have helped tube amps a lot to control the cone movement. All this results is a increase of fine dynamic details and a better resolution of finest overtone harmonies. The light weight paper cones have a much lower mass to be driven and can therefor much better controlled by a given tube power amp, resulting in a improved sensitivity. The heavy HPD cone (double weight through the stiffing back support brackets and the three layer high power voice coil 85W) does not only make the double power output possible, it needs it it to be adequately driven.When the Monitor Gold was changed already for the establishing transistor amplifiers, the highly maneouvrable HPD cones are a clear reminiscence of the adaption to the high power output transistor amplifiers of their time. When used with tube power amplification, in particular with low power DHT tubes, the HPD drivers show mirrored characterics of the former chassis. All the live, color and speed in lower mid frequencies is gone, to me it sounds quite uninspiring and retarded comparing it with the earlier drivers. Within this drivers the front loaded funnel cannot add any extra quality to the soundstage. The well known front loaded funnels from the Autograph and Westminster cabinets are a perfect extension for the 15'' dual concentric driver. Such a design helps fundamentally to conduct the cone radiation to the air of the listening room. In theory it works like a pantograph with a adjusted transmission ratio. The finer physical resolution of the stiff light weight cones completes the full potential of this design feature. A clearly listenable quality advantage of wider spread tonality and much improved micro dynamic response are the obvious benefits. In a horn design principle the cone almost works at its physical optimum, since it is not retarded by the air cushion of a closed cabinet. A further fine adjustment of the crossover design will complete this positive effects. My personal experience was once initialised by the classic 12'' chassis (Monitor Red and Silver), where Ronnie H. Rackham set the Lf-cone as a fullrange unit. Later with the Monitor Gold line (1966) Tannoy limited the 12'' inch chassis performance with a 12 dB filter cutting above 1500 Hz. This intervention brought a flat measured response in the 1000 Hz region, but it can be easily approved, that it takes out a lot of micro dynamic detail. To my taste it sounds slower and a bit uninspiring, so I do like the more lively presentation in full range mode a lot better, even if there might be some little uneven inaccuracies in the measured response. Starting from this experiences and accustomed over the years with every day use, I missed the benefits of the full range driver when I restarted to listen to the 15'' chassis (Gold, Red and Silver) some years ago. Together with my first test of the front loaded funnel I changed here the crossover into full range mode. This intervention is a basic principle for the following incorporation of the front loaded funnel with greatly improved success. The Westminster and Autograph have as well verified (lower) crossover points in conjunction to the front horn opening. I tested both filters as well in my set up and decided to stay with the unfiltered full range mode for my 15'' Monitor Red drivers as to be a superior solution. With the rejection of the filter for the Lf-cone even with the bigger 15'' units, two important advantages come together. First the sensitivity gets a better ratio. I am sure that the cone gets into trouble at the upper end of its physical ability. It will show a good portion of deformation in the measured response curve, this starts around 4000 Hz and peaks around 8000 hertz with already 6 db or even more loss, so it does not have a fundamental effect to the overall sound. On the other hand the uncontrolled cone plays so much better in terms of dynamics and speed in the important 1000-2000 Hz area, that I can accept the effect as almost completely positive. As already said in other articles, the concentric high frequency horn is cut at 1000 hz with a 6db filter in the ordinary crossovers. Listening with the front loaded horn funnel shows a dramatic better distribution and dispersion of fine detail and micro dynamics in this most important tonal range around 1000 Hz, due to its acoustic coupling from 400 Hz on to the higher frequencies. It gives a 100% better front radiation of the cone and helps the high frequencies to be supported into the lower registers. Here almost every instrument or any voice will be covered with finer micro dynamic abilities. The overall soundstage is dramatically improved in its illusion of width and depts and the impression of air is noticeably extended, so this change has a fundamental impact with extremely positive effects for my new design. Another word about measurements. They can help to find some problems, they can shorten evaluation proceeds, but their graphics doesn't say anything fundamental about sound qualities and their harmonic structure. If you look to graphs of measured natural instruments, they show a tremendous deviation from the idealized flat response. It is almost a opposite fact, the most colorful tonal presentation with the best harmonics in overtones, show the most degraded graphs. I don't think that the publishing of graphs shows any content about musical response, so I don't show them. "Copy and Paste" in China. I do not know what these copies will cost, nor do I know where to get them. I do not know if they will even match my high expectations for tonality and natural musical response...but they are made from plywood. I wish to have a chance to listen to a pair of these?! The original two versions don't differ in size but in material choice of their boards and used drivers. The Royal (with HPD derivate driver) is made from plywood, since the TW (Tulip Waveguide, speakers with horn exposed dome tweeter and with ferrite magnet) is poorly made from chipboard. I would state, that without the support of the front loaded horn the Tannoy does only do half the job and is a different speaker. After two years of implantation in my set up, I don't find back to the plain ordinary response with typical turning point filter at 1000 hz in the classic crossover. I have tried several times to switch back (with different cabinet designs), for me it is very easy to do, I have built a switch into my network to be operated from the outside of the enclosure. I tried again and again with different equipment and in different rooms – I always tried with and without the funnel – no way, I cannot accept anymore the classic approach. It is now a different loudspeaker to go. Try yourself, the intervention into the network, its easy to be done, just bridge the capacitor and the coil at the Lf-rail with a crocodile clip wire, – done. For the funnel to test, I can recommend a simple version made from 2mm grey card board as a first stage. This will show almost all the benefits with your existing speaker enclosure. If you have Lancaster cabinets, remove additionally the back panels and position the speakers almost 1 m (4 ft) as minimum distance in front of the backing wall. I swear, you never have heard such a good sound from your Tannoy speakers, if your chain is able to supports it. Don't fear this step, it will be reversible in 5 minutes... And if you do, please ... let me know what you think about! Read on soon about constructing the new open baffle enclosures in the Christmas holidays, Volker All photographs shown from Google with respect to their unknown original resource.
Outdoor noise comes in many varieties: mechanical equipment, HVAC, fans, pumps, trains and more. Many municipalities place restrictions on noise levels.
Contrary to what you may have heard, flex duct will NOT solve all ventilation-related soundproofing issues.
I’ve wanted to build these for a while. To cut right to it – for the small outlay of cash - the OSMTS are legit & I cannot speak highly enough of...
Dedicated for acoustic guitarists, the AC-RV creates spacious sonic soundscapes suited particularly to the natural character of an acoustic instrument. It has a mode switch offering hall, spring and room reverbs, and two depth modes as well. Description MOEN AC-RV Acoustic Guitar Reverb Pedal Dedicated for acoustic guitarists, the AC-RV creates spacious sonic soundscapes suited particularly to the natural character of an acoustic instrument. It has a mode switch offering hall, spring and room reverbs, and an A/B toggle switch offering two depth modes as well. If you want a dedicated reverb effect for your acoustic guitar, this is the pedal to choose from the MOEN range. Reverb for Acoustic Guitar A well made acoustic guitar naturally generates a reverberated sound, and if set up in the right space, they will require more subtle reverb effects. If your guitar pickup is configured in a way which doesn't translate the inherent acoustic properties of the body cavity, a well designed acoustic reverb pedal does wonders in lifting the atmospheric and acoustic active spaces, and with the choices of spring, hall and room reverbs, the AC-RV is a fitting solution to generating a natural reverb to match your musical tastes. MOEN Effects - A Special Breed At the very beginning MOEN promoted completely handmade guitar effects under the CFX label which received high praise from guitar players lucky enough to snag one. CFX also made "special request" pedals and designs and catered to some pretty well known guitar names. Ultimately, pedals made by hand could not satisfy the rapid growing demand any more, therefore from early 2005 CFX joined with MOEN and built a new production line. The pedals produced on this line are originated from the original CFX circuit design, maintaining the outstanding tone, and keeping the distinct enclosure and surface process. Features: Designed for acoustic guitarists 3 Mode Toggle - Hall-Spring-Room A/B Toggle Mode Time and Mix Control Knobs Compact and Tough Metal Enclosure True Bypass Specifications: Dimension: 114L x 65W x 52H mm Weight: 220g Power Supply: (Not Included) DC 9V Current Draw: 140mA Input Impedance: 500k ohm Output Impedance: 10k ohm No Duty to Canada and USA Free USA Shipping Ships from Canada *Just to be clear on DUTY, (regardless of what Etsy warns buyers of ) Canada and the USA have a trade agreement in place that allows US citizens to purchase/import up to $800 dollars per purchase in to the United States from Canada with NO Duty at all, State taxes are another story, some states charge a TAX some do not, BUT NO duty.
Hello to everybody interested reading further about my 15'-Tannoy enclosure loudspeaker design. A bit more than a year time has passed since the dipole based front loaded enclosure has been finished in its final form and did set place in my everyday audio setup. Today, after that time, I can say this was one of my most important steps in my whole audio life towards a refined, smooth and absolute natural audio response. Since last February these speakers have given me so far the rare present of hundreds hours of inspired musical listening pleasure, were the technical aspects of its origin did step into a background role. In the former 30 years I have owned several different original Tannoy speakers/enclosures with almost all types of drivers with alnico magnet. All these loudspeakers are quite well known and have several fans around the world. They all show up with similar audible characteristics and attitudes. Their very conspicuous presence of articulation, illusion of space and exceptional dynamic abilities, which are common similarities independent of size and enclosure principle, have made Tannoy to a classic in audio history. They perform in a well known robust tradition where other similar vintage makes from Altec, Jensen, Stephens, University and more are gathering, but were refinement and natural aspects do not play the foremost attitude, instead their typical common habits are more or less similar cheeky frequency ends. The Tannoy typical reflex/vented port cabinet designs (like Canterbury, Lancaster, Mansfield, Cheviot, Arden, Devon and their similar designed predecessors), but as well the highly favored back loaded horn designs (like Autograph, GRF, Corner Canterbury or even both Westminsters) are good examples for more than prominent low frequency response (but unbeatable excellent all-time favorite selling arguments). The latter group extend this spectacular attitude into the region of lower mids as a result of the to short and to small opened backing horns, mixing up with a cocktail of unwanted wooden resonances as a result of large interior surfaces of the horn development. Excuse me, these classic speakers might be able to fulfill the claims with typical attitudes of electrical amplified performed rock music, but for lovers of naturally performed and articulated music with delicate dynamic structures such designs are are of no use, unable to represent a full spectrum of micro dynamic information. For audio gourmets these classic designs need a lot of work to be a final choice. A loudspeaker is one of the most important components in a audio set up. As the final transducer of electrical signals into acoustical waves it has a important function. If it is unable to transform the signals without harmonic relevance and dynamic finesse, other components will not be able to catch up the loss. My enclosures did lead my long term relationship with Tannoy Dual Concentric alnico drivers into a complete new adventure of unknown land. My listening experience with such "full range" horn installations from Linemagnetic LM22A/LM555/LM597 with TA7331 inspired the dipole woofer idea for my enclosure, as the LM22A did inspire the front loaded funnel for the medium frequencies (to be honest since the middle 1990ties I did plan to add such funnels to a typical Tannoy enclosure, but I never realized this idea before 2014). Within several articles I have honored the "best audio set ups I personally have listend to" and I am still in hope to extend this experience one day with a larger wooden horn like WE15A in a similar refined set up. My own unique way to follow such exceptional sets uses a Tannoy Dual Concentric speaker in combination of dipole enclosure, where the purposed half is formed to act like a front loaded horn development and the backing part acts like a traditional open chamber. Such a front horn helps to overcome the most difficult fault of the large 15'' paper cone. The medium frequencies response between 500 and 1500 hz will be mechanically amplified and supported, a tonal spectrum where a cone speaker of such mass and size is physically limited in its ability of resolution finer harmonic details. In the same time the funnel does act as a extension of the cone, who itself is already a seamless extension for the high frequency driver. So the horn is enabled to conduct lower frequencies with its wider and longer opening development. Not only to my personal taste the Tannoy high frequency horn is known to be one of the best two or three horn tweeters built ever. It shows up with a exceptional rare attitude, its seems to be unlimited extended in its higher frequency performance, since it is at the same time completely acoustically invisible, as any for hf-horns typical superficially is at the same time completely absent. Horn development as seen from the mouse, the funnel extends the cone, who itself seamless extends the hf-horn. Additionally the funnel enables the cone to conduct a larger air mass. The dipole principle for low frequencies was a early simple invention to obtain fast and naturally sounding low frequency response in early cinemas of the 1930 to 1950 years. Together with the open baffle principle, which is physically seen as a similar design, it was in these days preferred over any closed or ported cabinet design. These came into account when the amplifiers started to be powerful enough to drive small enclosure types to allow complex filter units for massive corrections of low frequency radiation. The dipole shows some advantages comparing it to other designs, like the fastness of the transients, the completely uncompressed tonal expansion and the non-existence of any wooden resonances, which are typical for all cabinet priniciples. Open baffles mostly fail any acceptance in living room surroundings because of their space consumption (a square meter plus wings is a minimum to obtain some LF below 100 hz). The folded baffle into a such dipole design ends up with a quite room friendly size of typical classic speaker enclosures (here my speaker dimensions are 90 x 55 x 45 cm, HxWxD). But the backward radiated energy makes a delicate room positioning necessary. The speaker radiates wide parts of the frequency spectrum in anti phase mode, a effect which makes a minimum distance to the backing walls necessary to avoid problems. Anything closer will result in typical phase erasure and adding effects, both can degrade the tremendous abilities of the speaker. I have positioned mine with a distance of 60cm from the backing walls. On the other hand the funnel helps to direct and disperse the forward radiated energy, which is a another welcome advantage, this helps to keep the vagabond room reflections in almost perfect control and limits further room treatment to a minimum. If you can set up the speakers with such space, you will be rewarded is one of the most dynamic and expressive loudspeakers available, together with a rare freeness of resonances and a exceptional refinement of finest micro detailed harmonies, most other speakers of that league cannot compete with. My speakers show up with the typical grill cloth at the back opening of the enclosures. Detail of the backside, the former installed sliding mechanism is completely redundant. So I have removed the rails and fixed the inside enclosure, the shown felt seals are not any longer useful. The former planned blinds to adjust the backward radiated energy are as well completely redundant. One of the two best 15'' Dual concentric speakers of the Tannoy line: Here the reconed Monitor Red with specially designed crossover to complete the enclosure design with front loading. Later versions show up with higher paper cone weights and less optimal impedances for low power tube amplifiers. No other duplex speaker design in history makes such a seamless integration of high to low frequency with front loaded funnel possible. I am now extremely happy about the behavior of this a phantastic speaker, a result which I didn't expect when I started to built up that concept. More than this the speakers are able to work in a highest possible stage of harmonic audio response with a almost invisible holographic dynamic soundstage other speakers of that size do not follow. This speaker works so refined that it made possible to detect several limiting aspects in my chain, which in former times I was not able to detect and resolve. I hope that such design will find some more interest in the coming future, Volker
