Peerless India drivers: old notes

I have been asked so many times on the diyaudio forums about Peerless India drivers that I decided I should pull out my old notes and write them down here, so that others don't go round digging up old info the way I had to do.

The following is an email I wrote to a few friends on 12 July 2004, reproduced verbatim:

    Dear all,

    My friends and I went and met Jeetubhai on Saturday. Quite an
    interesting experience.

    He is the sole wholesaler of Peerless India products in India. He operates
    from a small shop in a dirty road (in the monsoons, all roads in Bombay
    are filthy) in interior Ghatkopar. He supplies drivers to three retailers
    in Lamington Road. And he seems to have a steady and reliable supply of
    drivers... he is confident that he can supply 2000 drivers to me at one
    day's notice. In fact, he seems to be carrying huge physical inventory.

    Therefore, I feel that we may now think of designing speakers based on
    Peerless drivers, at least those which Jeetubhai says he can supply. (No
    12" or larger woofer, for instance... the largest you get is 10", fs=26Hz,
    Qts=0.38 or so. And Peerless does not supply Vas.)

    Interestingly, Pandam, Telome, Lithos, and Sonodyne are direct
    customers of Jeetubhai.

    So, one can get the reliable fabric dome SR10DT dome tweeter, 1" dia,
    good flat freq response, which Angshu had used and which I will use for
    my current ongoing project. He also has a silk dome one with a lowish fs
    (1335Hz) and equally flat response. I'll use it for my next projects.
    And there are a couple of other domes, including an Al dome with

    Then there's a 3" so-called full-range, a 4" woofer, a 5.25" woofer, an
    8" woofer, and a 10" woofer. Prices, prices, prices:

        SR10DT 1" fabric dome:          Rs. 540
        T25SM 1" silk dome:             Rs. 500
        T25AG 1" Al dome:               Rs. 600
        LK-76 3" full range:            Rs. 275
        KO100 4" midbass:               Rs. 480/500
        SKO130 5.25" midbass:           Rs. 575/650
        SKO204 8" woofer:               Rs. 725
        SKP254 10: woofer:              Rs.1750

    When two prices are given, it means that the lower one is for unshielded
    and the upper one is for shielded.

    Jeetubhai has sworn us to secrecy about the prices, saying that his
    resellers should not even hear that he's spoken with a retail customer.
    And he said that for retail quantities, we should contact his resellers.
    For larger quantities (I'd think about a dozen total, mixed bag will do),
    I can, as a special favour from him just to me, contact him directly. So,
    group buys will be a good idea. :)

    All these drivers have a stamped powder-coated basket and coated paper
    cone (tweeters of course are different), with rubber surround, and as
    per the datasheet, fairly decent magnet sizes. Unfortunately I can't
    scan and send you the datasheets because he's given me photocopies and
    these are about the faintest photocopies I've ever seen. I can barely
    read half the figures myself.

    In addition, he has one incredibly sexy looking real Kevlar driver,
    6.5" midbass, which he is not reselling through any of the resellers.
    This one he is reselling for Rs.1400 each. The finish on that driver
    is something else. It has the characteristic yellow convex-curved cone
    (i.e. the slopes of the cone are not a straight line, but a bit convex,
    bulging forward from centre to edges), rubber surround and a black phase
    plug. The basket is cast (probably Mg), and has the uniformity, finish,
    and sharp edges of a jewel. The basket's spokes have back-turned edges,
    like you find with well-finished high-end high-power woofers. These
    back-turned edges are finely finished to sharp edges. The mounting flange
    is wide enough for easy mounting, and it slopes to sharp edges on the
    outer rim, thus making recessing and counter-sinking unnecessary. I've
    seen the Vifa P17, and I can vouch that in terms of finish quality this
    one is as good if not better. I've seen the Jordan JX92S, and this one
    is in that league, purely in the eye candy context. From the graph, it
    seems you can xo it at 2.5K, maybe even a bit higher, I don't know. So
    it should form a totally stunning looking component to a two-way or an
    MTM. How it sounds is of course the Great Mystery, but even getting a
    driver so well-finished in India, made in India, is quite amazing.

    This is the only Peerless India driver I saw which has the VAS
    mentioned: 36.86L. Qts = 0.39, Fs = 39Hz, short term power 300W,
    long-term power 100W. Peerless India apparently tests for long-term
    power as per some IEC 268-5 standard, which involves playing the driver
    continuously for 100 hours at the rated power level. :) VC dia = 25mm,
    VC height = 11.5mm, air gap = 5mm, Xmax = +/-3.25mm, Re = 5.67 Ohms,
    piston area = 137.07 sq-cm.

    I will be keen on buying four of these Kevlar thingies myself, and as I
    mentioned, I need to go to Jeetubhai for these. Anyone else interested
    in trying them? If anyone is thinking of the Vifa midbass drivers from
    Corrson, I'd think these should certainly be worth a shot. In fact, I
    feel that these drivers will be 10 times superior to the Vifa TC18 ones
    (those ones have plastic baskets, and these don't just have stamped
    metal frames, but actually cast metal ones, for starters) at a lower
    price. They may (just may) even be better overall than the Vifa P17 ones,
    which cost 2.5 times as much.

    If any of you want to see what similar Kevlar cone drivers look like, go
    to a BPL-ProFX showroom and check out their speakers... they use Kevlar
    midbass drivers.

    For three-way designs, the 5.25" driver seems to be a bloody good
    midrange, going by paper specs. One can use them instead of the Bolton
    16SJW22 which I'm using now, for about the same price. The finish of
    these will be better than the Boltons, and the piece-to-piece variation
    of parameters will probably be less. And for woofers, I think I'll just
    settle for the 10" drivers henceforth. Putting two of those drivers per
    side should give me a piston area comparable to a 15" driver per side,
    and with decent Xmax, T/S parameters and attractive price to boot.

    For two-way, there's nothing to beat the Kevlar cone for midbass duty.
    ("If music system looks good, it sounds superb." -- Gooroo Angshoo
    saying.) If I'm on a lower budget, I may opt for the tried and tested
    Bolton 16SJW22. And for tweeters, I guess I can just stick to the SR10DT
    or try the T25SM instead of opting for expensive Vifa D27 ones. Now that
    we know that supply is unlikely to dry up in the next couple of years,
    we might as well try these out?

    For retail quantities, contact:

    1.  Dev Electronics (1st floor of a building opp L.Rd Police Stn)
    2.  Chowdhury Trading (below Dev Elec, gnd floor)
    3.  Lalwani (close to Chowdhury)

    All three are on the same side of L.Road, on the main road itself, and
    are easy to find. Of these, Dev seems to be the keenest to sell
    Peerless, and Chowdhury is reluctant. For the Kevlar cones, I guess we
    will have to go back to Jeetubhai.

    For the first time I now feel that driver availability is now no longer
    a problem for me, on an Indian income, in India. I'll be happy working
    with these drivers for all the projects I can think of building.

    If any of you want any of the figures from these datasheets, write me.

That about covers it. As I write this page in July 2008, I know a few things are different:

  • You don't have to go to Jeetubhai to get the Kevlar cones, they are available from Dev Elec. They are all available from Dev.
  • I don't have any of those old datasheets that Jeetubhai gave me. I lost them, and I don't mind, because I know I need to measure any drivers I use anyway. And thanks to Angshu and others, I can do all those measurements today.
  • That Kevlar cone driver is as sexy to my eyes today as when I first set eyes on it in that tiny room in Ghatkopar. But its basket is not Mg as I'd first guessed. It's some sort of polycarbonate, just like the Vifa TC18 ones. So all my initial comments about it being superior to the TC18's basket were wrong.
  • There are more tweeters available from Dev Elec than the ones I listed. And the one I used in the Asawari Mark 1 is the same as the one listed here as T25AG, I think. Dev Elec called it the TG25. It's metal dome, Fs of 1500 Hz or so.
  • There are not one but two 10" drivers. The differences are in the magnet size and power rating. From the front, they look identical. Their baskets appear identical too.
  • Prices have gone up. Dev Elec quoted Rs.1800 per Kevlar driver last week. When I'd bought my first lot from him, they were Rs.1600 each.

Still, for those of you looking for some sort of information, this note may be useful.

I still stand by one remark I made in 2004. This range of drivers will suffice to make all sorts of 2-way and 3-way speakers. They're good enough for me. Angshu has used the 8" paper cone ones for some projects and they've proven very good performers. The others that we've dabbled in and bought samples of are also very well made.

It's now hard to sympathise with the Indian DIYer who keeps saying there are no usable drivers available in the Indian market. Yes, the NA and EU markets have a much wider range, and better drivers, but I feel like asking the constantly-complaining Indian DIYer: Have you acquired the technical knowledge and proficiency to build speakers which will actually be able to gain from their quality difference of those imported drivers? I know I haven't. I'm still happily using Tang Band El Cheapo drivers, Bolton 16SJW22, and Peerless India drivers, and friends who hear the speakers I make are thrilled with their sound. Angshu's speakers are even better.

After playing around with some of the best drivers ever made (I had a pair of Jordan JX92S for a few years) and listening to $30,000 music systems at friends' places, I've come to the conclusion that well-made drivers with coated paper cones can deliver really lovely sound in intelligently designed speakers. What's more, they are far easier to design for than fancy things like metal cone (e.g. the Seas Excel or the Dayton RS ranges) drivers.

When we fail to drive well, we wish we had better cars. When we can't even measure the SPL curve of a driver, we keep telling ourselves we'd have made El Fantastico speakers if we only could purchase those Scanspeaks and Fostexes. To each his own fantasy, I guess. :)

next: pointers to some datasheets

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