Driving external speakers with Sony HT receivers

P

proloyc

Beginner
Hi All,

Would want to know if it's possible to run external speakers with the DVD-player-cum-amplifier that comes with the Sony home-theater-in-a-box models (say, DAV-DZ150K).

My requirement is primary for high-end music reproduction. So I am looking at purchasing Wharfedale Diamond 8.4 (or 9.2) speakers. But I want to cut costs on the amplifier+source combination. So was wondering if I could buy a HTIB for the living room, and the Wharfedales for my bedroom, and use the same Sony receiver to drive them.

The Sony receiver rated output is 108 W per channel at 3 Ohms. The Wharfedales can take 20-150 W per channel, but are impedance-rated at 6 Ohms. So my question is: will the Sony receiver be able to drive speakers at higher impedance levels than its rated capacity. If so, what will be the compromise? Will it start distorting or lack detail? Or will the power output be reduced? I'm ok with the latter -- a power output of even 50W per channel is fine with me, as long as no overheating of the receiver or the speaker takes place. I'd be using them for near-field listening only, and not too loudly.

Has anobody tried to drive external speakers in this arrangement?

Also to note is that the output pins on the Sony receiver look proprietary, and I'm not sure if one can use the same wires for connecting external speakers.
 
You have two issues to consider:

1. The connectors on the back - you can only get them as replacements from Sony directly.

2. The output amps on the Sony are digital and output correctly into one specified impedance only. Above and below that, the frequency response changes. On connecting a regular 8 ohm speaker the response become tinny and lacks bass. This not a defect, the amplifier being digital has an output filter, this is by design and is a necessary compromise in a digital amp.

You'd be much better off buying a regular amp. Apart from the SQ issues, there may be HF nasties that can take out your tweeter, due to an incorrectly functioning output amp filter.
 
SONY!= high end sound EXCEPT IF SUFFIX = ES :P

the supplied sony speakers should also be higher than 3 ohms. they just show rated power at lower impedances just to make it seem more powerful. yes you can drive them both, and given that the sony amp claims to drive at 3 ohms , it should be able to drive both the wharefedales and its own , provided its own speakers are >= 6 ohms . but its recommended that you use a switch, and drive only one at a time , and besides , it makes more sense :D

dunno about the connectors, but a little wire surgery should be able to do the trick ;)
 
sangram said:
You have two issues to consider:

1. The connectors on the back - you can only get them as replacements from Sony directly.

2. The output amps on the Sony are digital and output correctly into one specified impedance only. Above and below that, the frequency response changes. On connecting a regular 8 ohm speaker the response become tinny and lacks bass. This not a defect, the amplifier being digital has an output filter, this is by design and is a necessary compromise in a digital amp.

You'd be much better off buying a regular amp. Apart from the SQ issues, there may be HF nasties that can take out your tweeter, due to an incorrectly functioning output amp filter.
Click to expand...

Oh its a digital amp? Yuck :no:

also my previous answers are not valid for digital amps

get a regular amp dude. cheap digital amps are just a gimmick
 
Thanks for your replies.

Yes, one of the reasons I'm considering these ones is that they have a Class-D amplifier (digital amplifier that is). And I guess what they are saying makes sense too -- there would be loss if a digital signal (from the source) is first converted to analog (D->A), then reconverted (A->D), and amplified and finally producing analog output. Instead the digital amplifiers amplify the digital signal itself before analog enters anywhere in the picture.

Why do you think it's objectionable? In fact, these designs dissipate less heat and thus should be more durable as well apart from distorting less.

I read elsewhere that better control on dynamics is achieved by having a higher current. For louder volumes (more physical movement of the diaphragm) you need greater voltages. So low impedance speakers should inherently draw more current for the same output voltage, and thus have better dynamics and control. If you read Onkyo documentation they advertise low-impedance, high-current capabilities. Probably it has to do with simple physics, heat = current squared * resistance. So lower impedance (implying higher current) should imply better heat dissipation capability. They should inherently be better at withstanding heat.

On the contrary, higher impedance would imply lower current and thus less problems for the amplifier on the heat front.

So it looks like if higher impedance speakers are used less current would be drawn and there might be loss of dynamics. I'm ok with loss of loudness but not that of dynamics. But I'm not sure which one becomes the casualty here -- that can only be known by plugging the two (Sony+Wharf) together!

Moreover, impedances are said to be *nominal* and I'm not too sure how that is to be interpreted. May be it means the impedance at a fixed frequency (1KHz or something). Because the impedance is wildly variable depending on what the frequency is, with treble frequencies causing higher impedance.

So it's likely that at bass frequencies the Wharfedale impedance will be lower and probably closer to what the Sony amp is designed to drive. So I'd anticipate less problems there. It looks more likely that at midrange or higher frequencies the Wharfedale impedance may exceed the design capacity of the Sony. So that should translate to poorer (or distorted) response in that range. Or is my understanding incorrect here?

Just to clarify, I don't intend to use both sets of speakers (the 5.1 and the 2 Wharf stereo) together. They'll primarily connect to the Wharfs alone, and only occasionally (even rarely) the 5.1. They'll be in separate rooms too, and I'd physically move and reconnect as required. Not switching.

Moreover, the Sony satellites are rated at 3 ohms each. I've seen the documentation. I've also auditioned them. They can go very loud without distorting.

The fundamental question is: for a given amplifier, which is the more difficult task? -- driving lower impedance speakers, or driving higher impedance speakers?
 
lol proloyc, you remind me of myself 4 years ago :bleh: Even i used to think that technology was the brute force path to sound. Its not quite. Good sound is more of a black art, which you will realize if you dabble a bit in analog electronics. There are only so many things you can do to ensure fidelity (high quality components etc) but at the end , it just boils down to trial and error.I bought an audigy 2ZS platinum pro, with more decoding formats and technology in it than most HT recievers south of 75K at that time(DD EX, DTS ES , THX, 7.1, 192KHz/24 bit, you name it , i had it . I thought it would sound great. it didnt. it was quite ordinary. what made me cry was when i connected a plain old CD player to my speakers ...it was only then that i knew my speakers could sound THAT good :cry:

The question you should be asking yourself is , do you want a system which sounds good in paper, or a system which sounds good to you ?

as for your last question, its better to get high impedance speakers. except for lesser sensitivity, they ought to be better otherwise :) for the amp driving them,distortion, frequency response , damping , etc
 
^ Obviously driving lower impedance speakers, since

Voltage = Current*Impedance

Naturally, as Impedance decreases more current is needed to drive the speakers, keeping voltage almost constant.

As for Digital Amps, the less heat dissipated part is true, but they just don't cut it for serious listening.

As you yourself pointed out that dynamics are much better, all warmth in tone is lost.

If fact, some of Sony's high end 7.1 amps are all digital and use processing modes to give a"warmer" tone (yuck!)
 
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