Heresy Ohm setting with other series.

[Ohiopatriot]

Just aquired a mint HII WO set(sonic heaven) and have a question about ohm settings. Yamaha HTR-5850 6.1 (I know, i know). The RF25s I switched with the HII are 8 ohm along with my RC35 and RS10(have a small living room). Because the HIIs are 4 ohm, I switched setting to 4 on the receiver. Is that OK with the 8ohm others?? Yes, im dorf at this but am learning. Back in '85/86 when I was stationed in Berlin Ger.I heard my first set of Klipsch(Heresy) when my roommate purchased HBR at the PX. Its been 24 years and finally, now I have my very own to squeeze tight!! Hope Im OK at 4. Thanks in advance!

[russ69]

Are H2s four ohm? The H3s are 8 ohm nominal.

Thanx, Russ

[Islander]

First, Heresy II speakers are 8 ohm. Second, no need to apologize for using a Yamaha AV receiver. Lots of forum members are happily using them, either alone or as pre-amps with outboard power amps.

In any case, do not use the 4 ohm impedance setting on your Yamaha receiver. This has been discussed a number of times on this forum and others. From a previous post:

When I first got my RX-V750, I set the impedance switch at the 4-ohm position to suit my "4-8 ohm" rated speakers (not Klipsch), but I was never really happy with the sound. I did a little research and found that the switch was installed to satisfy some sort of electrical code requirement.

Switching to the lower-impedance position limits the voltage to the power supply rails so the amp will run cooler, but it really compromises the bass response.

This was posted on Audioholics:

Also, be sure to set the impedance Selector Switch to: 8 Ohm Setting

Never set the impedance switch of a receiver to 4-ohms!

Note about the 4 ohm setting on the backpanel of the RX-V3000

Selecting the 4 ohm setting significantly limits the rail voltage feed to the power amps and thus reduce dynamics, bass output and damping factor. This switch was put on the Receiver for marketing purposes, and so that it can meet UL approval for heat dissipation when presented a 4 ohm load continuously with minimal to no ventilation. With proper ventilation, this should never be a problem (at least 4 inches above and behind the Receiver). In addition, the Definitive Technology Speakers are very efficient ( > 90dB) and thus are relatively an easy load for the Receivers Amplifiers to drive in the 8 ohm setting. Thus I would have to say setting the Impedance Switch to the "8 Ohm" setting will result in better fidelity for your system.

I also found this:

(quote, taken from SoundAndVision article)

"The Yamaha RX-V2600 delivered near-benchmark performance on every test, and literal benchmarks for linearity (0 error at -90 dB) and PCM signal-to-noise, which measured -75.7, the theoretical ideal for our dithered-silence test. Power was impressive for just about any common real-world speaker load, including all-channels power. The receiver shut down when confronted with high-output/low-impedance stresses with its impedance switch set to "6 Ohms," but did fine on the same loads with the switch "mis-set" to the 8-ohm position."

One more from Audioholics, in a test of the RX-V659:

Choosing the Speaker Impedance

Yamaha still ships their receivers with the dreaded impedance selector switch. Our advice as always is to use the "Minimum 8-ohms" setting regardless of the impedance of your speakers. See our editorial note below for further elaboration.

Editorial Note about the Impedance Selector Switch

I recommend the "Minimum 8-ohms" setting even for 4-ohm speakers of moderate efficiency ( > 89dB SPL). Yamaha includes a" 6-ohm" setting to satisfy UL heat dissipation requirements when driving 4-ohm loads, as well as easing consumer concerns about driving low impedance loads. These switches step down voltage feed to the power sections which can limit dynamics and overall fidelity. My advice is to keep the switch set to "Minimum 8-ohms" regardless of the impedance of your speakers and ensure proper ventilation of the Receiver. Using the 6 ohm setting will reduce power output to your speakers about 15-20% and thus cause higher frequency of amplifier clipping if driven too hard which can damage your speakers.

After reading all this (just Google Yamaha impedance switch, without quotes), I set my switch to 8 ohms and the bass instantly improved, so I could turn the bass control back to Flat and enjoy the sound. I've used the 8-ohm setting for over two years now with no problems.

CAUTION:

Do not move the switch unless your receiver is turned off!

You

will

cause damage if you move the switch while the unit is turned on!

[Ohiopatriot]

Islander, Thank you very much for the detailed info. I apologize for my ignorance concerning the ohm setting. But that is why I joined this forum. To get help and correct info when needed. I am thrilled with MY Heresy II and look forward everyday to listening to their majic. Thanks again for your time!

[Ohiopatriot]

AND Russ. Thank you also!