Which begs the question - with so many independent US speaker manufacturers selling 4ohm bookshelf designs for HT now, why are the receiver makers currently producing such limited amp sections. I see this creating a disconnect in the industry if it continues. I'm thinking something will have to give, eventually. Maybe the Japanese are, once again, intentionally making it difficult for US manufacturers to compete using their platforms. I suspect that Japanese receivers probably have no problem pushing Japanese speakers, esp the crap ones being marketed here in the States.
I love a good conspiracy.
DJ
Its not that simple. In order to provide high powers you need a lower impedance, as otherwise the voltage gets so high the output devices spark across the semiconductor material and fail. However low impedance requires large current and therefore robust output devices and power supplies. This increases heat, in a box with increasingly complex and frail microprocessor chips. And yes there is a trade off between complexity and speed versus fragility.
In order to correct for the diffraction roll off of narrow fronted cabinets, dropping the impedance below 600 Hz is pretty much mandatory.
For these reasons I regard receivers as a solution of convenience. There is nothing else to recommend that approach.
The real way out of this mess is pre pros and active speakers. In addition to avoiding all the issues of passive crossovers, diffraction loss is applied ahead of amplification, which makes the whole issue of amp design easier, and cheaper.
I'm convinced that if the industry got geared that way, and ditched the receiver concept, then you cold get better performance at less cost, and with greater reliability.
As well as less capable amp sections I see an increasingly shortened life span for receivers.
If the new receivers are only putting 70 watts into a resistive 8 ohm load under test, then they are only putting about 25 watts into most real speaker loads.
The real issue is that receivers were never a good idea, and with the increasingly complex environment, they become a worse idea by the year. Persisting with the concept is going to limit performance gains and reliability from here on out.
The other issue is power consumption. I think it is only a matter of time before regulatory agencies demand class D amps. They are already regulating TV power consumption in Europe, and now California. The move to class D will pretty much cause a change to active speakers in my view, as class D amps hate complex impedance curves. Also half or more of the provided power will not be wasted in the passive crossovers as is now the case. Second order crossover consume around half of the amp power and a lot of fourth order ones close to two thirds.
I think it is only a matter of time before energy conserving legislation tips the balance to active speakers.
