Lsi 7 & 9

renowilliams

Just wonder if I were to purchase one of these models, given their power requirements, whether my avr would drive them ok in 2 channel.

Ender

From reading what others were saying about their 4ohm speakers and this receiver, it should be fine to use with the LSi series.

BlueFox

renowilliams wrote: »

Just wonder if I were to purchase one of these models, given their power requirements, whether my avr would drive them ok in 2 channel.

Your AVR is quite the beast at $4500 list price.
http://www.pioneerelectronics.com/PUSA/Products/HomeEntertainment/AV-Receivers/EliteReceivers/VSX-49TXi?tab=B

You should be fine. I ran 4 LSi15s and an LSiC off a $1000 Sony and Denon AVR with no issues in full HT mode. Two channel should be no problem. Personally, while the LSi7s are nice little speakers (I have two), I would get the 9s, or even the 15s instead.

I must add the obligatory Polk Forum disclaimer here: You need an external amp with the LSi series. Blah, blah, blah.

cnh

Good work on the blah..blah...blah...you are right.

Hey Tim....what does that Pioneer say on its speaker terminals? 6-8 ohms or is there a 4 ohm setting?

cnh

Rocco1

CNH is right you need to check out what Pioneer says about running 4ohm speakers.

Not that you couldnt hook them up and you would hear sound, but you would probably mess the speakers up.

renowilliams

This is what Ultimate AV mag said when it did a review and took measurments;
With six channels driven into 8ohms (our test bench load is limited to six channels), the VSX-49TX clipped (1% THD+noise) at 123W at 20Hz and 129W at 1kHz. With six channels driven into 4ohms, clipping occurred at 187W at 20Hz and at 201W at 1kHz. The receiver shut down on the latter test from a blown internal fuse, but functioned normally again when the fuse was replaced. This test is extremely challenging; such a failure would be very unlikely in normal operation, even high-level playback of the most explosive music or soundtrack. With five channels driven into 4ohms, the Pioneer clipped at 196W per channel at 20Hz and 209Wpc at 1kHz, left channel measured, without shutting down. The output with five channels driven into 8ohms was 133W at 20Hz and 137W at 1kHz. With two channels driven at 1kHz, clipping occurred at 168Wpc into 8ohms and at 241Wpc into 4ohms, left channel measured, at 1kHz.—Thomas J. Norton


Not quite sure what it means though.

OK, just read the manual and it says nominal impedance of 6-16 ohms. Guess not.

Oh well, Guess I'll have to get a power amp. I wanted an excuse anyway...lol

Bernal

renowilliams wrote: »

This is what Ultimate AV mag said when it did a review and took measurments;
With six channels driven into 8ohms (our test bench load is limited to six channels), the VSX-49TX clipped (1% THD+noise) at 123W at 20Hz and 129W at 1kHz. With six channels driven into 4ohms, clipping occurred at 187W at 20Hz and at 201W at 1kHz. The receiver shut down on the latter test from a blown internal fuse, but functioned normally again when the fuse was replaced. This test is extremely challenging; such a failure would be very unlikely in normal operation, even high-level playback of the most explosive music or soundtrack. With five channels driven into 4ohms, the Pioneer clipped at 196W per channel at 20Hz and 209Wpc at 1kHz, left channel measured, without shutting down. The output with five channels driven into 8ohms was 133W at 20Hz and 137W at 1kHz. With two channels driven at 1kHz, clipping occurred at 168Wpc into 8ohms and at 241Wpc into 4ohms, left channel measured, at 1kHz.—Thomas J. Norton


Not quite sure what it means though.

Simple, can not set the LSI to hear sing.
Amplifier 300 watts at 4 ohms is basic.

---

1) DENON AVR-4308CI: Advanced 7.1 CH/5.1+2 CH/ 3.1+2+2 CH A/V Home Theater /MultiMedia Multi-Source/Zone Receiver with Networking and WiFi/170 watts x 7 channels
2) HITACHI P55T501. 55" HD1080 Plasma HDTV
3) OPPO DV-980H 1080p Up-Converting Universal DVD Player with HDMI and 7.1CH Audio
4) DENON DVD-2500BTCI: Blu-ray Disc™ DVD/CD Digital Player/Transport (
5) POLKAUDIO LSiC (Center speaker)
6) POLKAUDIO LSi15 LEFT (Front speaker)
7) POLKAUDIO LSi15 RIGHT (Front speaker)
8) POLKAUDIO LSif/x LEFT (Surround speaker)
9) POLKAUDIO LSif/x RIGHT (Surround speaker)
10) SONY SA-WP16 ( Sub Woofer 2X200W)

cnh

You might be able to run small LSIs with that but don't push them too far. That's my reading on those specs. Do you have a manual? And does the manual say anything about a 4 ohm setting for speakers. Because although, in most cases, like the Onkyos, such settings are limiters that reduce actual wattage. They save you from blowing fuses or speakers...and that Pioneer has pre-outs so you can always get external amps later...and just run them with the Pioneer. I can't imagine that the Pioneer would NOT be able to run them at decent volumes--that was the flagship that year!

cnh

Kex

renowilliams wrote: »

This is what Ultimate AV mag said ...

Not quite sure what it means though.

There are quite a few reports of using the Elite models with 4 ohm loads. Polk Audio c/s also added in one thread that the LSi7 are actually more 6 ohm, and not that difficult to drive. Nonetheless, if the product manual does not specify that it has 4 ohm capability, Ultimate AV are not going to pay you one cent when Pioneer refuse to replace your blown tweeters. The LSi9 are known to dip well below 4 ohms.

Check your facts very carefully. Some receivers are actually well known to be fully rated for 4 ohm use, and lower, without any power limiting switches or other nonsense (albeit, not very many). Of those, I have never heard a single report of failure or protection modes being engaged with difficult loads, so you will not be risking damage to your speakers or voiding your warranty, but they may not have all the processing abilities that first attracted you to the Pioneer.

After that, you'll have to decide if you want to be Cathy approved for flight, or not, and others will join her to argue that you will never get the best out of your LSi speakers without 200w/ch of external amplification. Only you can decide what your priorities are, but at least be aware of the possible consequences.

P.S. The price of a receiver has nothing to do with whether or not it can drive a 4 ohm load.

renowilliams

Well there is no sence taking chances. I will buy a power amp before I get 2 channel speakers. Thanks for the info everyone.


Much appriciated.


Tim

Systems

Actually for a multi ch reciever it appears to do a credible job driving 4 ohm loads.It certainly didn't fall flat on it's face according to Ultimate AV's test.

Face

cnh wrote: »

You might be able to run small LSIs with that but don't push them too far.

Actually, the LSi9 is a more difficult load than the LSi15. The 9 dips down to 2ohms, meanwhile the 15 only dips down to 3ohms. I haven't tested a LSi7 or 25 yet, but I would assume that they're the easiest to drive.

Bernal

Face wrote: »

Actually, the LSi9 is a more difficult load than the LSi15. The 9 dips down to 2ohms, meanwhile the 15 only dips down to 3ohms. I haven't tested a LSi7 or 25 yet, but I would assume that they're the easiest to drive.

Is that true?
As verify the information?
Has the file or web address.

---

1) DENON AVR-4308CI: Advanced 7.1 CH/5.1+2 CH/ 3.1+2+2 CH A/V Home Theater /MultiMedia Multi-Source/Zone Receiver with Networking and WiFi/170 watts x 7 channels
2) HITACHI P55T501. 55" HD1080 Plasma HDTV
3) OPPO DV-980H 1080p Up-Converting Universal DVD Player with HDMI and 7.1CH Audio
4) DENON DVD-2500BTCI: Blu-ray Disc™ DVD/CD Digital Player/Transport (
5) POLKAUDIO LSiC (Center speaker)
6) POLKAUDIO LSi15 LEFT (Front speaker)
7) POLKAUDIO LSi15 RIGHT (Front speaker)
8) POLKAUDIO LSif/x LEFT (Surround speaker)
9) POLKAUDIO LSif/x RIGHT (Surround speaker)
10) SONY SA-WP16 ( Sub Woofer 2X200W)

Face

The LSi9 impedance curve is easy to find via google. I tested a LSi15 with a WT3(woofer tester 3).

Systems

Verified by the NRC.
http://www.soundstagemagazine.com/measurements/polkaudio_lsi9/

BlueFox

GV#27 wrote: »

Verified by the NRC.
http://www.soundstagemagazine.com/measurements/polkaudio_lsi9/

Looks like the average impedance is around 5-6 ohms.

Systems

The problem area is in the 200hz range and below where both woofers are operating in parallel and the dip to 2 ish ohms at 50hz which appears to be the ports tuning frequency.
There is usually a lot of musical content in this range, so combined with the lowish impedance will make it quite demanding of the amp driving it.

Bernal

GV#27 wrote: »

Verified by the NRC.
http://www.soundstagemagazine.com/measurements/polkaudio_lsi9/

BlueFox wrote: »

Looks like the average impedance is around 5-6 ohms.

The information is very old. Is the same for new versions of the LSI.
Have results for LSi15?

Face

Those specs should be the same as current. As I mention above, according to my measurements LSi15's only briefly dip down to 3 ohms, so any 4 ohm capable amp shouldn't have a problem driving them.

danz1906

Your AVR will work,but an Amp will be much better.

CaligulaPolk

renowilliams wrote: »

Just wonder if I were to purchase one of these models, given their power requirements, whether my avr would drive them ok in 2 channel.

you paid 4500 for avr?

renowilliams

CaligulaPolk wrote: »

you paid 4500 for avr?

No. That was the MSRP of my reciever when new.

Systems

xcapri79 wrote: »

The link to the LSi9 impedance measurement appears to have disappeared. Are the actual curves posted somewhere else in this Forum?

For some reason the NRC measuresments of the LSi9's on Soundstages site are not acessable.

McLoki

xcapri79 wrote: »

The link to the LSi9 impedance measurement appears to have disappeared. Are the actual curves posted somewhere else in this Forum?

Here you go....

VXR8

After that, you'll have to decide if you want to be Cathy approved for flight, or not, and others will join her to argue that you will never get the best out of your LSi speakers without 200w/ch of external amplification. Only you can decide what your priorities are, but at least be aware of the possible consequences.

Agree with what Cathy always suggests - I have the said speakers (LSi9) that I did initially drive through a Rotel RB-991 2 channel amp - 200 watts into 8 ohm / 300 into 4 ohm. I sold the said amp and was running my LSI-9s through my Denon 3808 only. Although it did sound acceptable still, the full capability of the speaker was no longer there - a noticeable difference. I again now have a Emo MPS-2 200 watt into 8 ohm x 7 / 300 watt into 4 ohm x 7 and the full potential of the speakers have been restored.

There is a good old saying, you never know what you have got until it is gone.......