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New Harbeth P3ESR

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  • #76
    P3ESR compared with earlier monitor ....

    As you may know, from time to time we offer a trade-in facility for the BBC (or BBC staff) to donate their old BBC-designed speakers (LS3/5a, LS5/9 and LS5/8) to us and in exchange we give them a very attractive deal on new Harbeth Monitror 20/30/40. The old monitors are historically useful - as this example. Last week, a BBC operation sent us a pair of old 3/5a, the date code stickers say 1984 and 1985. They asked us to evaluate them to check that they were working and then to send them a pair of M20 - and an invoice. They are not Harbeth-made LS3/5a as they are clearly marked "15 ohms, 25W speech and music" and all Harbeth LS3/5a are of the later so called 11 ohm computer optimised type from 1988 onwards. Today, I hooked them to the necessary XLR sockets (yes, the BBC XLR rule is that speakers have XLR plugs not sockets) and played them.

    Needless to say, I was greatly influenced by the LS3/5a when I designed the original P3 in 1990, but that was nearly twenty years ago, and the 3/5a itself dates from 1974 - that's thirty five years ago. So we are comparing a speaker designed ten years before the CD was introduced with the P3ESR designed some twnty five years after the CD. There should be differences; technology has progressed. The LS3/5a uses first generation plastic cones: the P3ESR uses fifth generation RADIAL2? cones, and the cone material defines the quality of the speaker.

    First impression: how very quiet they are; they seem to need a rally big push from the amp to make an acceptably loud sound. Second: how recessed they are on vocals (such as Michael Jackson's Bad). Third: How weak the bass is. Finally: I have them playing in the background and the overall impression is one of uninvolvement. And of a really small scale of performance. I am not sure if these are atypical, but the contrast with the P3ESR is really quite shocking. These make the performers sound as if they are in the next room.

    PS. It's occurred to me that you may be surprised that I am shocked. You may have assumed that I have spent months switching backwards and forwards between the P3ESR prototype, the LS3/5A and other mini monitors. That's not how I work. I'm attempting to capture the essence of what I'd hear in the studio in the loudspeaker under development, and I carry the sense of that in my head. I can judge when I have eliminated the unwanted man-made artifacts in the fledgling design, and at that point, side by side comparisons are useful to confirm that the design eclipses the best previous designs. Beyond that point, as little by little over the months the design edges forward there is really no need to look backwards.

    Since I finished the P3ESR design a couple of months ago, I have not listened to hi-fi at all. My task is complete - the fun for you is about to start. Hence, when the opportunity is presented to make a comparison long after the design is frozen and in production, it really is amazing just how comprehensively the P3ESR outperforms the earlier models. As someone commented, the P3ESR is alive, open and fun. Now I understand what they mean; to me that is the essential Harbeth quality and I take it for granted, but if you live with other speakers you really are in for a treat when you hear the P3ESR - or indeed any RADIAL-coned Harbeth.

    Attached picture of the better looking (!) ex-BBC monitor we received. Note XLR plug (in very unusual place) and metal hanging bracket.

    >
    Attached Files
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

    Comment


    • #77
      P3ESR - communicates like no other

      Fun is what the P3ESR is about. It's a big speaker in a small box. A beautifully crafted small box but large in sound.

      I've heard many small speakers, some described as 'monitor, but I've not heard a better small speaker than the P3ESR. It communicates the performance like no other and has a presence which takes you into the performance. It's fast, pacey, dynamic, natural and the vocals are so in the room that it is startling. As for the bass - where does that come from Alan ?

      This is the speaker the LS3/5A should have been !!!

      Comment


      • #78
        Re: P3ESR - and LS3/5a design legacy

        I appreciate the feedback. It's interesting that you've mentioned (on a couple of occasions) the P3ESR's remarkable bass performance. Clearly this has made an impact on you - good - that's what I intended!

        I thought I'd re-read my design brief for the P3ESR as I posted it here. Note that I listed good bass performance as essential, with midrange clarity and ease of drive also as high priorities. By now, your accumulated concentrated listening experience and wide choice of music and electronics probably exceeds mine, mine spread over many months, so your opinion is most likely to be more useful than mine. But certainly, when I first played Eminem (unpretentious self-effacing rap, well recorded, great fun, one of my favourites) - see link - even I was astonished at the subjective bass quantity and quality. Link here: (low grade audio just as an example - the CD is really clean). Beware! Lyrics may/will be offensive! Eminem

        The Harbeth RADIAL2*? bass unit .... that's the secret of the P3ESR. I'll explain more later. It took hundreds of hours of computer simulation (all documented so I can share this with you over the months) and fifty prototype woofers (I've kept most of them in the archive) over a four year design period. We froze the design at No. 50 and cloned that. So what you have in your P3ESR is a clone of my master reference Woofer 50.
        Alan A. Shaw
        Designer, owner
        Harbeth Audio UK

        Comment


        • #79
          Re: New Harbeth P3ESR

          Alan,
          Eminem - are you sure ??? I never would have put you down as a rap fan, down in the hood !!!

          Whatever, I'm impressed with the little P3ESR and if there's any justice, you've got a winner there.
          David

          Comment


          • #80
            Eminem rules - OK?

            Yep! Absolutely! Great stuff! My wife and I won a Quiz Night at the local pub because I was the only person in the room (of middle aged folk) who knew Marshall Bruce Mathers III's stage name! And I had to insist that our team wrote down Eminem as none of them had heard of him. Tut Tut.

            The recording clarity and balance of Eminem's The Eminem Show is really excellent: the sound is extremely smooth and the stereo imaging excellent. Other tracks on there that are great demo pieces but the language is, er, somewhat choice so I hesitate to create links! Beware!

            I've noticed that rap music is probably the smoothest, best recorded type of modern music.
            Alan A. Shaw
            Designer, owner
            Harbeth Audio UK

            Comment


            • #81
              Re: New Harbeth P3ESR

              Respect !!!

              And respect for making some truly excellent speakers. I'm just annoyed with myself for not discovering them years ago. I've been wasting my time all these years.

              David

              Comment


              • #82
                P3ESR - measurements @ BBC anechoic chamber

                I attach pictures of the prototype P3ESR being measured. I was undecided as to which direction to steer the woofer's characteristics and in such a situation the only option is to make a selection of variations,and then take them to an environment well away from reflective surfaces. Then it's the fiddly task of installing them one by one into the reference cabinet, calibrating, putting them in position and taking some acoustic measurements. Working entirely alone and unaided, and with the pressure of $2000/day hire charge, one has to have a very clear measurement strategy when one arrives to get the most value from the session. There is not much time for analysis* - that can be done later back off-site. Every effort must be made to make absolutely reliable, repeatable measurements or subsequent man-months of computer simulation will be garbage.

                I should add, in answer to an earlier comment about the 3/5a, that the BBC were extremely fortuitous that the off-the-shelf KEF B110 (midrange) driver had enough bass to be used in what became the LS3/5a. In my view, any speaker brand with pretensions of designing a really high quality mini-monitor must design and manufacture the bass/mid unit themselves. This is the only way to optimise the parameters of sensitivity, extension, power handling, distortion etc.. A bought-in woofer from a far flung supplier who has no in-depth understanding of or more important, empathy with the magic of the BBC mini monitor concept cannot hope to balance the technical parameters suitable for the 'British shoe box monitor'. There are very few of us woofer manufacturers amongst the last remaining 'British' brands.

                *I wish it were this simple. The video camera was running during some of this session. On playback, I was surprised how many minutes I stood unmoving staring at the measurement computer's screen undecided whether woofer A, B or C was best. Weighing up in my mind the balance of characteristics as displayed and whether a further ad hoc adjustment could be made on site to make the best candidate even better.

                >
                Attached Files
                Alan A. Shaw
                Designer, owner
                Harbeth Audio UK

                Comment


                • #83
                  Re: New Harbeth P3ESR

                  There are countless 'box stuffers' out there but the only way to design and make a truly great speaker is to have the skill, knowledge and facilities to design and manufacture your own drivers. Without this ability, a design can only go so far.

                  Comment


                  • #84
                    Skills needed to design at this standard ....

                    The primary qualification needed to design good monitor-grade loudspeakers is a reliable internal memory of live sound. All other skills can be acquired if you have a natural curiosity about audio equipment and are willing to learn, to actually roll up your sleeves and make and listen to a physical loudspeaker rather than a fancy mathematical model in a laboratory. And then to mentally deconstruct what you hear into frequency bands, and from frequency bands into a correlation with the physical loudspeaker parts. No general engineering training can give you those skills.

                    There are two other prerequisites: First, the designer must have an immense respect for the BBC's loudspeaker R&D heritage (and a real understanding of what they achieved, why they achieved it and how ). I was immensely lucky to be an unpaid Saturday volunteer at the local BBC radio station when I was in my early-mid teens at exactly the moment the LS3/5a appeared in the studio. I was hooked.

                    Second, there is no place for the self-delusion that the designer could somehow, with limited R&D resources, develop a revolutionary new loudspeaker that the BBC with their huge resources couldn't. In other words, any progress that we at Harbeth are likely to make will never be to the core-concept of the 'BBC monitor' but to the detailed execution of that concept. The RADIAL2? cone is the perfect example of how we took our founder's* pioneering polypropylene cone and continued the development where he left off. In audio engineering a formal engineering background is not needed, and may prove to be a handicap. The BBC's greatest director of engineering - H.L. Kirke - had a penetrating insight into engineering problems and like Faraday and many other great engineers was entirely self-taught.

                    Read about the BBC's H.L. Kirke and Harbeth's founder BBC engineer Dudley Harwood* here. Without these men and their audio legacy, the Harbeth company wouldn't exist.
                    Alan A. Shaw
                    Designer, owner
                    Harbeth Audio UK

                    Comment


                    • #85
                      Re: Easy load - yes of course it is

                      Results from a user who reports excellent amplifier compatibility (as I would expect) with P3ESR. Read here and here.
                      Alan A. Shaw
                      Designer, owner
                      Harbeth Audio UK

                      Comment


                      • #86
                        Re: New Harbeth P3ESR

                        I have spent the past couple of afternoons in the company of customers, listening to the amazing P3ESR. We used a Rega Saturn for the CD player and various Nottingham Analogue turntables with assorted arms for the analogue side. Amplifiers were Rega Elicit, Naim XS-2, Naim Supernait and the new Croft pre/hybrid power. Nothing too exotic.

                        First observation is that these little speakers sound huge !!! I had to smile when one casual listener, after a couple of minutes, said 'can I hear the small ones now ?'. He thought the large speakers in the corners were playing. That;'s the second time this week I have had that happen.

                        Second observation is that these diddley little speakers produce real bass. Not the usual one note, ever present colouration that passes as bass from most small speakers but deep, tight, punchy, communicative bass that plays tunes. Amazing for such a tiny box.

                        Third. These little fellas make perfectly balanced music at low volume levels. I like my music loud and am fortunate in having a separate building in which to play my music but most are not so fortunate. Unfortunately, very few speakers make much sense at low volume settings but I could quite happily listen all day to the P3ESR at background levels. In fact, we listened at very low levels for two hours this afternoon and I enjoyed the experience.

                        Fourth. The fit and finish is examplary. You can't help touching and fondling them and admiring the build. They are beautiful in a traditional, British built but thoroughly modern way.

                        This is a truly great speaker.

                        Comment


                        • #87
                          Re: New Harbeth P3ESR

                          Fifth. They are fast ! They remind me of my Quads. Attack is immediate. No ringing, no artifacts, no excuses. Wow, I am blown away, and have no urge to set up my SHL5's or any of my other dozen or so speakers.

                          Comment


                          • #88
                            Re: P3ESR - measurements @ the Village Hall

                            There are two fundamentally different approaches to 'accurately' measuring the frequency response of a loudspeaker. I say accurately with considerable caution. It's actually impossible to move the loudspeaker so far from reflective surfaces that the measurement is only of the speaker alone, with absolutely no contribution from the measuring space.

                            Still, the early loudspeaker designers (probably in the 1930s) realised that something had to be done to minimise the room's ability to corrupt the frequency response measurement at the microphone (which couldn't separate the speaker from the room). One way to minimise the room's contribution is to soak up the reflections by lining the room with soft, absorbent cushion-like material, hence the anechoic chamber. There is one of these free-field rooms at the BBC Research centre, designed and built in the 1960s long before the digital measuring era and as far as I know, I am the only person who pays to use the BBC chamber these past few years. I always take my own digital measuring system and calibrated microphone which I've built into a blue portable box. I showed pictured taken there on the previous posting.

                            However, the advent of high-precision digital measurement systems such as mine reveals that even the BBC chamber is far from reflection-free. In fact, there are many small but irritating reflections off electrical fittings and the steel mesh floor (needed for safety) and I always take a pile of cushions to position here and there to damp down the reflections. That then allows a measurement of the speaker with only a small (but still present) contribution from the chamber.

                            There are two alternative measuring strategies: outside on a warm windless day, high off the ground and indoors as far from walls as possible. After some research touring village halls in the area, I found that the Scaynes Hill Millennium hall (built with support from the National Lottery recently) has a very high ceiling and an even decay curve. I've used that hall during the development of the P3ESR (see picture).

                            How do the results compare between the traditional "analogue" BBC anechoic chamber and the "digital" village hall measurement? Well, under perfect conditions, they give the same result. Surprising considering one is very lively and one very dead? The secret is that the digital measuring system (unlike the old analogue pen and paper chart) can clearly differentiate between the direct sound reaching the microphone from the speaker first, and then the later arrival of that sound reflected off a hard surface. So the trick is to window the measurement so that all of the direct sound is allowed through the digital off-on gate and just before the first reflection hits the mic, the digital gate is snapped shut. After some experimentation I'd previously found that this room-asymmetric position of the mic and speakers gave the best result. Since sound travels very slowly, providing the walls are at least about 2-3m away, this gives long enough 'on' gate to get a really good measurement of overall frequency response, but as with all these sophisticated systems, there is a long learning curve. So, we have three methods which weather, cost and convenience permit virtually identical results when set-up and used carefully.

                            Incidentally, many of the Compact 7ES3 measurements during development were taken at the hall so this is a proven technique. The picture taken in Dec08 just before I set off to launch the P3ESR in Las Vegas CES shows the P3ESR about 3m above the floor, securely strapped to the stand). On the stage is the blue-box all-in-one mobile test rig with B&K microphone amplifier and ruggedised Panasonic Toughbook laptop running the measurement software. To their right is a collection of other mini-monitors for comparison including our "green label" BBC-provided reference LS3/5a used to calibrate the measuring equipment, and a P3ESR.

                            >
                            Attached Files
                            Alan A. Shaw
                            Designer, owner
                            Harbeth Audio UK

                            Comment


                            • #89
                              Re: Measurements at BBC v. local hall - the sound-energy curves ...

                              I decided overnight that to complete this comparison of alternative measurement environments used for the P3ESR design, that it may be of interest to show the same reference speaker (not P3ESR) measured under near identical conditions at the BBC anechoic chamber and the village hall, shown in the last posts. The key point here is that it is not necessary for you, the end user, to be asked to pay for exotic million dollar facilities because accurate and repeatable measurements can be made in very modest environments providing that the constraints of those facilities are well understood. In other words, when measuring loudspeakers, using a little brain power gets the same results as throwing lots of money at the problem. This way minimises the cost of your Harbeth speakers - and is a satisfying intellectual challenge for me!

                              At the BBC chamber, the speaker under test is on a short rigid stand, itself standing on the metal grid floor half way up the height of the chamber. At the hall, the speaker is on a telescopic pillar stand, and is raised high above the floor. My test equipment and B&K measuring microphone are the same for both. This was all part of the P3ESR design loop so to be sure that I was measuring the speaker, not the speaker + environment.

                              There are some interesting things we can observe from the two graphs - BBC chamber results at the top, hall below. NOTE: these curves show the sound energy as it arrives at the measurement microphone after a sound pulse (like a hand clap) is applied to the speakers inputs. This pulse makes it easy to see reflections in the environment around the speaker. These graphs do not show the frequency response of the speaker! The big pulse on the left side of the graph is the bit which with suitable maths can yield the frequency response of the loudspeaker being measured; the rest is mainly the room's contribution. Note how in both charts, the left pulse - the direct sound - has very similar characteristics. This indicates that even six months apart under totally dissimilar set-ups, the speaker's latent characteristcs are unchanged.

                              1. In both cases, the first major reflection (from a wall, floor or ceiling) occurs at about 20mS (one fiftieth of a second) after the direct sound from the speaker reaches the microphone. As the reflective surfaces are some way from the speaker, the speaker's signal has to travel to those surfaces and then bounce off them and then they must find their way to the microphone. This takes time, so the first signal to arrive at the microphone is always that directly from the speaker as that is the shortest route to the microphone.

                              2. After the first reflection there follow many others as surfaces further and further from the speaker receive the sound and then bounce it to the microphone. The comparison between the two environments shows a marked difference in the long-term situation: the sound bounces around the hard, reflective walls of the hall each one causing a reflection picked up by the microphone. But in the lined, damped anechoic chamber, the longer term sound is heavily absorbed by the lining and lost into the background silence. It doesn't reach the microphone.

                              3. The early reflection situation is different in these two environments. In fact, the village hall gives a better result than the BBC chamber. In the hall, the speaker and microphone are relatively far from the nearest reflective surface but at the BBC chamber there are many small hard surfaces in and around the speaker/microphone each of which give a little reflective sonic 'blip'. So the sound dies away faster and more evenly and completely in the hall before the first reflection compared with the BBC chamber. The reverse applies after the main reflection.

                              Which gives the best overall measurement that minimises the sonic degradation due to room reflections? Not so easy to give a clear-cut answer. For a short measurement window (up to 20mS) this particular village hall is the best choice: for a long-window measurement, the BBC chamber is sonically more inert. But there are workarounds for both.

                              Hope this is of interest.

                              >
                              Attached Files
                              Alan A. Shaw
                              Designer, owner
                              Harbeth Audio UK

                              Comment


                              • #90
                                Re: New Harbeth P3ESR

                                the P3ESR is with an enclosed design i.e. no port. anybody keen to elaborate in this particular design? and how does this design enhance the P3ESR (or P3ES2) performance? Tks

                                Comment

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