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Speakers designed with amps in mind and vice versa

Discussion in 'audio' started by mandryka, Oct 28, 2020.

  1. claire.foxx

    claire.foxx Trans lives matter more than cis feelings

    ATC Amp packs were all designed for their individual SCM counterpart speakers and bolted to the back of the cabinet.

    More recently

    The external ATC P4 is designed to work with and is only available as part of an ATC active loudspeaker system.
    ...and the P6 is a dedicated amplifier for the SCM150ASLT LE & the EL150.

    Back in the day when ATC offered a passive alternative and soffit installations, they used to use a lot of the old Crown amps, not “designed for”, mind.
  2. mandryka

    mandryka pfm Member

    We know that the best active speakers sound so good partly because their amps have been designed specifically for them. That’s right, isn’t it?

    If so, I’m wondering whether I should ask someone to design and build an amp, maybe modify an existing amp, for passive speakers which I like.
  3. Dozey

    Dozey Air guitar member

    I don't think that is right. I think I the amps are a given and the speaker is developed to work with them. Happy to be proved wrong.
    tuga and mandryka like this.
  4. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Absolutely wrong. No amplifier is designed to work with a specific speaker beyond having suitable power rating to drive it and in some same-maker cases having styling aspects designed to match it. Not even eg ones made by ATC to be bolted to the back of ATC speakers

    One will read loads on forums and in mags about certain speakers being designed for use with specific amps etc and EVERY bit of it is bollox. It is entirely marketing based! PMC and Bryston? PMC is UK distributor for Bryston amps!
    Shahinian and Dynavector amps? Same UK importer! Linn and Naim? I don't need to say anything...

    Think about it people... you would have to in effect build a fixed "graphic equaliser" into the power amp that gives small amounts of compensation for frequency response irregularities of the specific speaker this mythical "speaker specific amplifier" is meant to drive... or maybe even engineer into it a bizarre frequency dependent output impedance!
  5. Michael J

    Michael J pfm Member

    I think it is more that they are connected directly to them, typically one "amp" (channel) per driver, with "suitable" power level (per driver).

    Ed: meaning the tweeter only gets a 10W "amp" because that is all it really needs, while the woofer has "300W" because the marketing department think they can slide that one past you without having to explain what peak and distortion mean.
  6. fegs

    fegs pfm Member

    @Arkless Electronics as a designer what would a typical design brief be for a new amplifier? What are the requirements from a manufacturer when launching a new product?
    mandryka likes this.
  7. mandryka

    mandryka pfm Member

    So why do active speakers have such a good rep?
  8. claire.foxx

    claire.foxx Trans lives matter more than cis feelings

    Then there is Devialet who kind off turn the whole thing the other way around with SAM speaker matching that works on cone excursion modelling and how the amps draw current then there is multi-amping active with SAM with is insane levels of control. I can turn SAM on and off and hear the difference...

    And finally Devialet Phantom which is most certainly a speaker designed with an Amp in mind or is it the other way around? So tightly integrated that when the amp fails it's can only really be stripped and recycled... which is insane...

    Apple and Google is doing some very interesting things with the HomePod based on position and sensing its environment, to adapt to rear wall reflections and spatial awareness using DSP. Nest will be catching up.

    Its a pretty interesting time for amps and a whole younger generation of digital engineers really passionately pushing against the "amp in a box" idiom.
    mandryka likes this.
  9. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    As said above by Michael J. Each drive unit gets its own amp and is directly connected to that drive unit, no crossover... and lots of other advantages over a passive crossover-ed single amplifier speaker.
  10. mandryka

    mandryka pfm Member

    Right, I clearly don't understand what a crossover is. I thought it was something which sends some of the signal to the tweeters, some of the signal to the midrange drivers etc. So if that's right, you still need one in an active speaker.
  11. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Assuming an amp being manufactured commercially for profit here...

    A market sector would be identified where you don't have a product to sell or your present one is long in the tooth.

    As analysis of rival products in that sector would be made. Which is the best selling? Why? Which have flopped in spite of seeming to have something to offer and why?

    A basic spec is arrived at ie how many WPC? How many inputs? Remote controlled or not? What restrictions are there on width, height, weight etc

    A target price on the dealers shelf is set and then an analysis of how cheap can we build it for is done.

    From that a set in stone budget, including the styling and casework plus packaging etc is made.

    Circuitry is designed and breadboarded (a fully functional "lash-up" that looks like an explosion at RS and is built to be very easily added to/have changes made to it etc). This is then tweaked and played around with to get it operating in a stable and predictable manner and tests carried out to make sure THD, damping factor, frequency response etc are all OK and it gives the right amount of power etc. It may or may not be actually listened to at this stage depending on a number of issues relating to the practicality of it...

    This lash up amp and PSU will be analysed to see where it can be made cheaper or can have some extra feature that looks good in the brochure added to it.

    Meanwhile prototype casework will be getting made.

    A more robust lash up/rough prototype is built, both channels now (first go often mono) and some listening tests can be done to it. Until this point no one, not even the circuit designer, has any idea what it will sound like.
    Some tweaking etc will likely be done to maximise subjective sound quality but as long as it sounds "good enough", "par for the course" it will probably go ahead as is now.

    PCB design carried out and the whole thing production engineered to make it as cheap, quick and easy to manufacture as possible.

    More attempts at saving money usually gone through... can the spec of this or that part be relaxed so we can use the 2p each one instead of the 2.7p one, can we fit those made in China 4700uF smoothing caps rather than the 10000uF Rubycon ones the EE wanted to fit and without too many people noticing the difference? They really go to town on this as any money saved here goes straight on to the profit margin!

    This the generic kind of process that a reasonably sized manufacturer goes through with a new amp from my experience of being at the sharp end of the business.

    Note how small a part subjective sound quality plays in all this! So long as it's good enough so the average punter is going to hear a "hi fi sound" from it and there is no really glaring issue like... well like glaring treble, or really boomy bass or what have you then usually it will be taken as read that a sufficient proportion of punters will be sufficiently impressed to buy it in profitable numbers. Marketing, specious claims, dealer sales techniques, a few ahem.. "friendly" reviewers getting behind it plus glossy brochure and expectation biases etc do the rest...

    Sometimes things happen in a rather different order and less cynically... an EE may have tried a few topologies as background R&D, or have developed a circuit in his own time at home for his own use and has noticed it sounds unusually good, and so this circuit may be waiting in the wings when the requirement for a new amp to sell for precisely £699.99 comes along and this can then be adopted, giving it a head start... but not always!

    Some may recall my tale of Alchemists Far East distributor, responsible for maybe 70% of all sales, not even wanting to hear the Axiom integrated before taking it on! but being fanatical about cost savings and styling....
    This is the all so common reality of it folks...

    Many enthusiast run one man bands or very small enterprises run by genuine geek electronics audiophiles do things very differently and much more like you lot would hope for and expect yes, but for an Alchemist Products, an Arcam, a Musical Fidelity etc etc it's generally as I described IME.
    Durmbo, Miss Ariel, booja30 and 2 others like this.
  12. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    You still need one and yes that is what it does... In active it is done with small, precise parts operating at tiny power levels BEFORE the power amplifiers. There is no power soaking, damping factor destroying, awkward for the amplifier PASSIVE crossover AFTER the power amplifiers;)
  13. marshanp

    marshanp ellipsis addict

    As in "a right pain".
    gary yeowell likes this.
  14. fegs

    fegs pfm Member

    Thanks for taking the time to post that lengthy reply, much appreciated

    I've found that really interesting thanks, correct me if I'm wrong but having read it a couple of times it certainly seems just like a lot design briefs / specs, you're not necessarily designing something you would be interested in to use / buy yourself? I would imagine this is prevalent in a lot of industries where the designer or builder could also be the end user? it's obviously a case of designing to the brief regardless?

    Again thanks
  15. gary yeowell

    gary yeowell pfm Member

    Of course you are, you always are in your head.

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