LSi25, Yamaha RX-V3900 and Onkyo TX-NR1008.

Polk_Onkyo

I just bought the following brand new equipment:
1) A pair of LSi25.
2) Yamaha RX-V3900 receiver.
3) Onkyo TX-NR1008 receiver.

When I was at the store I was undecided between the two receivers,
thus I decided to buy both and return the one that I did not like.

I decided for these two receivers because they play 4 Ohms.

Now I am facing with the following situations:

. When playing the Onkyo:
No problems, but it does not sound as loud as the Yamaha.

. When playing the Yamaha:
It plays well until around 40% of the maximum volume, then
it turns itself off with the message: "Check SP Wire".

Note: The speaker wires are the same, I just remove them from
one receiver and connect them to the other.

Does any of you have any idea of what is happening?

Any help will be greatly appreciated.

Best regards and thank you in advance for any help you give me.

nguyendot

They don't "play 4 ohms". Those receivers are 8/6 ohms capable. If you want to power LSi speakers, please do a search on the forum about this topic.

Read this:
http://www.polkaudio.com/forums/showthread.php?t=111022

Polk_Onkyo

Thank you, nguyendot.
I will read the link.

It is a shame that some major electronic manufactures make
statements that are not true.

The following text was extracted from the Onkyo TX-NR1008 manual:

---

Speaker Impedance

4ohms:
Select if the impedance of any speaker is 4 ohms or more but less than 6.

6ohms:
Select if the impedances of all speakers are between 6 and 16 ohms.

---

The following text was extracted from the Yamaha RX-V3900 manual:

---

Speaker Impedance SPEAKER IMP
8 Min
Select this setting to set the speaker impedance to 8 Ohms.
The impedance of each speaker must be 8 Ohms or higher.

6 Min
Select this setting to set the speaker impedance to 6 Ohms.
The impedance of each speaker must be 6 Ohms or higher
(front speaker only 4 Ohms or higher).

---

If the consumer cannot trust what the manufacturer states in writing,
what can he/she trust?

What if:
. A Honda Civic does not have 4 Cyl, 1.8 L and 140 HP
as the manufacturer states?

. A Suzuki Hayabusa does not have 4 Cyl, 1340 cc and
6 speed transmission as the manufacturer states?

. A Polk LSi 25 is not really 4 Ohms and it does not have
an 88 dB efficiency as the manufacturer states?

We will become a society of total product anarchy!

If the manufactures are lying, why nobody sued them yet to
make them remove the untrue part of the text?

None of us can understand and be expert in all products and
different technologies, thus we have to rely on the manufacturer
data.

nguyendo, thank you again for your expert advice.

larry777

The Yamaha 4 ohm rating is for front speakers only. I believe you have to tell the Receiver as part of your setup that your front speakers will be 4 ohm. I don't think you can just connect the wires as 6 ohm and above without the other step of notifing the Receiver.

nguyendot

That's why I created the article, since so many people ask the same question. Hope it helped.

cnh

The Onkyo can run a 4 ohm speaker but it doesn't have enough juice at that impedance and you would have to set its menus for 4 ohms.

Here's the problem. It has a limiter that, more or less halves the wattage (or Less) at 4 ohms.

Even last year's flagship TX-SR5007, while it can hit close to its mark of 145 watts/channel in a 5.1 set up at 8 ohms (no problem!). Falls to less than 68 watts/channel if the 4 ohm setting is chosen. And that, frankly, for an Onkyo AVR is just not ENOUGH to do justice to an all LSI system.

The good news for both AVRs is that they both have pre-outs so you can get yourself a used multi-channel power amp that can do 4 ohms without breaking a sweat and use the Yammie or Onkyo as a pre-amp/processor?

cnh

tonyb

Polk_Onkyo wrote: »

It is a shame that some major electronic manufactures make
statements that are not true.

.

Welcome to the real world. You have to pay attention to the wording in any given spec. Some will say 2 channels driven,even one channel driven,or all channels driven. What good is a HT receiver spec in 2 channel if you know you will use it for 5 or 7 channel ? Most speakers don't stay at a given ohm anyway. They have swings sometimes,depending on the speaker of coarse,and can dip to 2 ohm causing a standard receiver to puke it's guts. Lots of variables apply here but generally speaking,a 4ohm speaker will require some added power above what most avr's can dish out. Manufacturers walk a thin line in my opinion of outright deceat. Even their rated power specs drop off a cliff going from 2 to 7 channels so keep in mind what you will be powering and how many channels. That said, for the LSI25's to sound their best,an added amp would help greatly. Good luck to you and read up on a few threads here to learn more on the subject.