SpeakerTalk

skiboy · Introductory Contributor Joined: 23 Sep 2003 Posts: 3

I have KEF reference model II for my front speakers, and just got the KEF Q-1 for my rear speakers. When I play music in 5.1 mode, the volume is much louder in the rear (Q-1) speakers than the front speakers! Does anyone know why this is happening and how I can adjust this???

terry · Posted: Tue Sep 23, 2003 6:47 am Post subject:

Good to have you on the Forum. You have a nice pair of speakers in the KEF Reference II.
I don't know if this is the answer but I note that the KEF Reference II has an impedance of 4 ohms and the KEF Q1 an impedance of 8 ohms. This could explain a difference in volume but I would have thought that your sound processor would have dealt with that. I am no expert on sound processors but I thought that it was usually possible to 'equalise volumes' using a test tone from which the individual speaker volumes can be adjusted. My sound processor does that. Which sound processor are you using?
Terry

skiboy · Introductory Contributor Joined: 23 Sep 2003 Posts: 3

Thanks for your reply. I have a Denon AVR-2600 receiver. I'm not sure that it has a volume equalizer. How does impedence affect the volume level?

terry · Posted: Thu Sep 25, 2003 7:13 pm Post subject:

Sorry I have been away from home for a couple of days.

I would have liked some of the technical experts to have contributed and answered this question. I suppose that since I have a degree in Electronics I have some basic understanding of the issues however. I should say though that I have not worked professionally as an electronics engineer.

I suppose I could say that if the impedance is higher, current flowing will be lower, and power output will thus be lower.

Ohms law goes along way to explaining this issue. Basically current = (voltage/resistance). For our purposes consider resistance to be impedance. You will see thus that an impedance of 8 ohms will thus restrict current flow more than an impedance of 4 ohms.

Power = Current X Voltage and so if current is lower then power is lower for a fixed voltage.

I know that it is more complicated than this but I believe that this basic explanation provides enough of an insight to see that speakers which are not matched in terms of impedance will not be matched in other ways with respect to sound levels output for example.

If you have a mixture of speaker impedances you could thus imagine that if power output is lower in one speaker over another then volume is lower. In the simplicity of my explanation I am setting myself up to be shot down here. Perhaps it is sufficient to say that a system which has not got speakers with similar impedances there might be some imbalance in output volume. Amps may also not like it as they would be faced with different 'loads'.

I wait now to be shot to pieces.

Terry

skiboy · Introductory Contributor Joined: 23 Sep 2003 Posts: 3

Terry,
You're first hunch was correct. I was able to adjust the volume through my receiver's test tone. Thanks for your input!

Lt.Bri · Posted: Mon Feb 23, 2004 8:16 pm Post subject:

terry wrote:

Good to have you on the Forum. You have a nice pair of speakers in the KEF Reference II.
I don't know if this is the answer but I note that the KEF Reference II has an impedance of 4 ohms and the KEF Q1 an impedance of 8 ohms. This could explain a difference in volume but I would have thought that your sound processor would have dealt with that. I am no expert on sound processors but I thought that it was usually possible to 'equalise volumes' using a test tone from which the individual speaker volumes can be adjusted. My sound processor does that. Which sound processor are you using?
Terry

KEF Q-1 are 4om speakers ( sticker on drive unit says that ).

Lt.Bri
_________________
Hasta la victoria siempre

Lt.Bri · Posted: Thu Feb 26, 2004 7:15 pm Post subject:

http://www.ixbt.com/dvd/kef-q-1.shtml => some nice photos of B160 SP1485 (drive unit from kef Q1).
_________________
Hasta la victoria siempre