Impendance Selector?

[Cygnus]

I'm planning on buying the Yammie HTR-5740S receiver. I think it seems really nifty. What do you guys think? I'm just planning to build a little theatre in my bedroom for my new house.


Im confused about the impendance switch though:

What side do i need it on and why does it matter?



Gotta save up some more cash though, only have $110.

 

[Nomo]

Almost always, the switch should be kept on 8 ohm. Unless you plan to add a separate amp, stay away from 4 ohm speakers. The Yamahas do not perform well with them.

 

[Cygnus]

I see...

What are ohms anyways and what does the number matter? Is higher good? or what?

 

[zumbo]

http://www.audioholics.com/FAQs/4-ohmspeakersreceiver.php

"ohm" impedance definition

 

[gene]

stay away from 4 ohm speakers. The Yamahas do not perform well with them.

Thats not entirely accurate. You can't just go by speaker impedance, but efficiency as well. In many cases a 90dB SPL @ 1 watt efficient 4 ohm speaker is an easier load than an 8 ohm 87 dB SPL @ 1 watt speaker to drive. You also have to look at the impedance/phase profile for the speaker since an 8/4 ohm rating is nominal and not representative of the actual load the amp sees. For example my RBH T2's are rated for 4 ohms, but look very resistive to the amp since they maintain a relatively constant impedance with phase swings no greater than +-30deg across the audible spectrum. They are also 90dB efficient.

In addition, Yamaha receivers such as the Z9 have no problems driving 4 ohm speakers, even the less efficient ones, especially when being crossed over to a dedicated sub as most do in home theater.

 

[Cygnus]

"Some Receivers have an impedance selector switch. DON'T USE THEM! The manufacturer puts them there for UL approvals as well as easing consumer concerns about driving low impedance loads. These switches step down voltage feed to the power sections which will limit dynamics and overall fidelity. Keep the switch set for 8 ohms regardless of the impedance of your speakers and ensure proper ventilation of the Receiver. " - Hooking up 4 Ohm speakers to an 8 Ohm receiver


That switch is just for the manufacturer, mainly, i take it?

Oh, and will the Voltage Selector be set to the right position when i buy it? or will i need to change it? (im in canada, and i dot know what voltage i would need)

 

[Buckeyefan 1]

Thats not entirely accurate. You can't just go by speaker impedance, but efficiency as well. In many cases a 90dB SPL @ 1 watt efficient 4 ohm speaker is an easier load than an 8 ohm 87 dB SPL @ 1 watt speaker to drive. You also have to look at the impedance/phase profile for the speaker since an 8/4 ohm rating is nominal and not representative of the actual load the amp sees. For example my RBH T2's are rated for 4 ohms, but look very resistive to the amp since they maintain a relatively constant impedance with phase swings no greater than +-30deg across the audible spectrum. They are also 90dB efficient.

In addition, Yamaha receivers such as the Z9 have no problems driving 4 ohm speakers, even the less efficient ones, especially when being crossed over to a dedicated sub as most do in home theater.

Gene,

Is this your system? If not, can you post a photo and components of your main system? That is a wicked center channel. I can imagine the midbass/midrange/voice capability for HT and jazz.

Todd

 

[zumbo]

Factory preset is 8ohm.

 

[Cygnus]

i meant for the power, not ohms.

 

[zumbo]

Buckeyefan 1: RBH

 

[Nomo]

A well deserved scolding

Thats not entirely accurate. You can't just go by speaker impedance, but efficiency as well. In many cases a 90dB SPL @ 1 watt efficient 4 ohm speaker is an easier load than an 8 ohm 87 dB SPL @ 1 watt speaker to drive. You also have to look at the impedance/phase profile for the speaker since an 8/4 ohm rating is nominal and not representative of the actual load the amp sees. For example my RBH T2's are rated for 4 ohms, but look very resistive to the amp since they maintain a relatively constant impedance with phase swings no greater than +-30deg across the audible spectrum. They are also 90dB efficient.

In addition, Yamaha receivers such as the Z9 have no problems driving 4 ohm speakers, even the less efficient ones, especially when being crossed over to a dedicated sub as most do in home theater.

I over-generalized. Sorry. Thanks for the correction Gene.

 

[Cygnus]

Well...thats another thing i gotta worry about now.. I'll probably use the speakers availible tto me until i have enough money for some good ones

*leavesm, checks imendance on Aiwa's*

6 Ohms. 40W Music Power. Will this work with the HTR5740?



One reason i am quite worried about all of this is that, when I had the Sony STR-DE345, which I wrecked...well....


OK, I had all the speakers hooked up to the receiver except for a sub. My dad wanted to listen to some music in the other room, so I thought "why not hook up one of these small speakers (the speaker was just one very small woofer, but the cabinet was big..oddly...) and put them in the other room?"

I handnt turned down the volume on the receiver prior to hooking up this new speaker, the volume on the receiver was pretty much at MAX. I hooked up the speaker, turned on the receiver, heard a *pop* noise...then, nothing


no display, no lights, no sound, nothing.


I had blew a board, i knew it....so i replaced that one with this aiwa as a temporary setup untill i upgraded (which im planning out, as you can see )


I'm worried about doing that same thing with this Yammie...not that ill do that exact thing. It's just that if i hook up these small speakers will they ruin the receiver? Thats also why I am scared of bookshelf speakers, as well...


Thanks,
trav

 

[zumbo]

It will run them fine. But may I give a few tips.
1) Never connect any speaker or equipment while the unit is on.
2) It is also a good idea to make sure the equipment is unplugged.
3) Never connect more than one speaker to a terminal. Every time you add a speaker to the same channel, the impedance is cut in half. For example, two 8ohm speakers run off of the same channel would make that channel see a 4ohm load.
4) Never run volume at max.

 

[Cygnus]

Thanks!

Good tips!

I did add a center speaker tomy aiwa not long ago, just to see what would happen.. I lost most of the low end in the main (meaning not the center speaker, the other one) seaker, that was hooked up to the same terminal.