LSiM 703 Review

polkatese

Very nice review Jim.

Reading the reviews, I think that 707/705/703 in a 5.1/7.1 setup would be an overkill, not to mention a rather unnecessary spending (read: a blasphemy to put 703 for surround job), even more so than a 9 (which I am using now).

Best case HT applications/2 ch passthrough would be a pair of 705 in the front and a 706c, with 9 and Fx for the rest. *thinking out loud*

JimAckley

Bernal wrote: »

Nice review.
That Pioneer Elite SC-37 will not be able to handle the 4 ohm load of the LSiM 703s. It's only rated for 6-8-16 ohm loads!

I'll bet you $20 it can drive a pair of 703s with power to spare. I'd know, I've seen it. I normally drive 7 LSis with the receiver without it breaking a sweat.

I wouldn't be ashamed to have 703s as surrounds. They're quite amazing. Now, 707s all around is overkill but not 703s. Atleast that's my opinion...

punk-roc

The Pio SC-37 is a beast.. it'll be fine..

Bernal

punk-roc wrote: »

The Pio SC-37 is a beast.. it'll be fine..

They may be doing the slider thing - 4 to 8 ohms average. If the speakers do not dip below 4 ohms - then you have a better chance. Some 6 ohm receivers can do 4 ohms - they just do it with less power. Keep in mind that impedace will fluctuate. Your speakers are rated at 4 ohms nominal impedance which means that the speakers are most often operating with 4 ohms of resistance. That impedance will fluctuate during normal usage and may dip as low as 2 ohms min (perhaps lower) and as high as say 8 ohms. For the THX Select 2 Plus certification you would have to ask THX what the 3.2 ohms refers to. I am not sure that guarantees that a receiver with that certification can adequately drive 4 ohm nominal speakers. Some 8 ohm nominal speakers will dip as low as 3.2 ohms during normal operation

txcoastal1

Bernal is correct I have clipped my 35 with some 9's wasn't as loud as you expect during a demo...but it was the source

stillen

The new Pioneer recievers coming out in a month or so will drive down to any ohm speaker up to 5 speakers with no loss of power.

> by chance did you get to listen lsim center channel or the surrounds to it.

thanx

mantis

I'm gonna have to comment on the SC37 , SC27 and SC07. I have not tested the SC05 , SC25 , SC35 with such loads but the 7 series does it with ease. I have loaded up at reference levels 4 ohms all around and no clipping. I drove 2 channel to reference levels with no clipping.
Good wire , good clean power , good sources , proper calibration , everything was fine.

EndersShadow

mantis wrote: »

I'm gonna have to comment on the SC37 , SC27 and SC07. I have not tested the SC05 , SC25 , SC35 with such loads but the 7 series does it with ease. I have loaded up at reference levels 4 ohms all around and no clipping. I drove 2 channel to reference levels with no clipping.
Good wire , good clean power , good sources , proper calibration , everything was fine.

Good to know. Would you still suggest dedicated amps since they can deliver more wattage than the AVR's can?

JimAckley

EndersShadow wrote: »

Good to know. Would you still suggest dedicated amps since they can deliver more wattage than the AVR's can?

For your room, yes. Since my room is small, it's not necessary. At least amplify your front channels.

JimAckley

stillen, all I've had so far is the LSiM 703s. No center or FX yet, sadly. I really wish I could review a 5.1 LSiM setup, but I highly doubt I'll get to do that anytime soon. Perhaps a year from now I'll have a 5.1 pieced together.

Tomorrow, or rather later today, I get the LSiM 707s. Now, before some of you cringe at the idea of 707s off of an AVR, keep in mind that, A) I'm not using a cheap Sherwood or Yamaha (remember those days mantis? :biggrin:), my listening room is only a 12x14x8 bedroom that opens up to nothing so it doesn't take much power to fill the room with volume, and C) I'll be bi-amping them from my SC-37 to make sure I have plenty of headroom, plus that should raise the impedance per each amplifier channel, making it less like two 4-ohm speakers and more like four 6 or 8 ohm speakers, which is an easy task for the SC-37.

I'll have them for a good big longer than the 703s, and I'll have the house to myself all weekend so I'll have plenty of time to put them through their paces. I might even see if I can get my buddy Phil's LMS Ultra 5400 and Crown XTi-4000 over here and make a real menacing 2.1 rig for a day. Either way, good times shall be had.

BeefJerky

JimAckley wrote: »

C) I'll be bi-amping them from my SC-37 to make sure I have plenty of headroom, plus that should raise the impedance per each amplifier channel, making it less like two 4-ohm speakers and more like four 6 or 8 ohm speakers, which is an easy task for the SC-37.

It doesn't work like that. Each channel of the receiver will still see 4 ohms nominal when doing a quasi-biamp like that. Besides, a quasi-biamp is unlikely to give you any tangible benefit whatsoever.

RuSsMaN

Regardless, I still have two Operetta stereo amps, 140/ch if the Pioneer doesn't cut it solo.

magic12kenneth

Jim,

Thanks for sharing your review. How is the clarity and detail when listening in low volume?

cnh

I'd take Russ up on his offer. The 707s 'do' need all the power they can get...they're a lot of speaker and have a substantial low end which the Pioneer won't do justice to. Even in the P-Fest run, Mark had the B-cue amp on them and that thing weighs a ton--a little/big beastie.

Enjoy the Demo. Do you have a forklift coming to pick up the 707s, lol.

cnh

JimAckley

magic12kenneth wrote: »

Jim,

Thanks for sharing your review. How is the clarity and detail when listening in low volume?

No matter high volume or low, the clarity is still there, the smoothness is still there, the midbass punch is still clean and tight. The thing that will surprise you most is how ridiculously smooth they sound. Everything about them is 100% pleasing to the ear. My only complaint in the whole review was that they didn't have the depth of modded LSi's, but keep in mind that modded LSi's set the bar pretty damn high.

cnh wrote: »

I'd take Russ up on his offer. The 707s 'do' need all the power they can get...they're a lot of speaker and have a substantial low end which the Pioneer won't do justice to. Even in the P-Fest run, Mark had the B-cue amp on them and that thing weighs a ton--a little/big beastie.

Enjoy the Demo. Do you have a forklift coming to pick up the 707s, lol.

cnh

He and I will talk about that whenever he manages to stop blowing me off so I can pick them up I was just about to see if I could go to Lowes and rent the forklift :biggrin:

BeefJerky

Jim wanted to know some more about why bi-amping still sees the same impedance that a non-biamped setup will see. I will try to explain it here for everyone. I've seen this question asked before, so it seems to be a common misunderstanding.

In the case of quasi-biamping like Jim wanted to try, it all boils down to the passive crossover. Each set of inputs only passes through a certain part of the frequency spectrum, and each of those bands has a nominal impedance of 4 ohms. When these inputs are jumpered/bridged, you aren't actually putting any drivers in parallel, you are simply connecting the one input to both the high pass and low pass on the crossover. As such, a driver (or set of drivers) will only be powered by the amplifier for a certain part of the frequency spectrum. When the amplifier is putting out a low frequency, it will only power and "see" the impedance of the low frequency drivers. When it is putting out a high frequency, it will only power and "see" the impedance of the high frequency drivers.

When you take off the jumper, you are then connecting the high pass and low pass input to different amplifier channels. Each channel will only be passing through either the high or low frequencies.

When doing real/active biamping the situation is similar. Except in this case you will not be using passive crossovers that feed from the amps, but instead using active crossovers that feed into the amps. Each amplifier channel will still only be powering a certain part of the frequency spectrum (and therefore only certain drivers). Each amplifier channel will still see the same nominal impedance that it would have seen if using a single amplifier channel with a passive crossover.

While active biamping is generally more beneficial, either of these situations can be undesirable. For example, if you have a single 200 watt amplifier powering a speaker, most of the power will go to the woofer since the lower frequencies require more power; very little actually goes to the tweeter. Now, let's say that you connect two 100 watt amplifiers in a biamp situation. In this case, the tweeter will not see any benefit, and will only draw a tiny portion of the 100 watts its amplifier can provide. In addition, the woofer can only get 100 watts rather than the nearly 200 watts from the non-biamped setup.

I understand this in my head, but it was fairly hard to put down into words. As such, I might not have explained this as well as I hoped. Please feel free to ask for any clarification.

JimAckley

Thank you Beef. I've been reading as much as I can about bi-amping this morning to try to learn more about it, and what you said makes total sense (atleast to me). Thanks for the clarification!


No the equipment for the review is not the best, but it's by far not the worst either. You're acting like I amped this with my Sony boombox. In a perfect world I'd have twin tube 200wpc monoblocks, but that's obviously not the case. The point here is that the SC-37 is sufficient to drive the 703s. They don't need a whole world of power, and are also more efficient than the LSi line. It's not like we're driving towers here... just a bookshelf.

BeefJerky

Jim, I'm glad I could help! It took me awhile to grasp the concept, so I wanted to share with others what I have learned.

As far as Bernal goes (and I hate to say this about another member), but you are better off ignoring him. He is constantly going out of his way to bash LSiM's (and anything related) at every opportunity. In addition, his is constantly taking any (mostly unrelated) opportunity to give a sales pitch for Magnepans.

Bernal

JimAckley wrote: »

... and are also more efficient than the LSi line.,.

This is a technical conclusion, and very good to know

JimAckley

BeefJerky wrote: »

Jim, I'm glad I could help! It took me awhile to grasp the concept, so I wanted to share with others what I have learned.

As far as Bernal goes (and I hate to say this about another member), but you are better off ignoring him. He is constantly going out of his way to bash LSiM's (and anything related) at every opportunity. In addition, his is constantly taking any (mostly unrelated) opportunity to give a sales pitch for Magnepans.

Well it makes sense. I always thought it was using a pair of channels for one speaker, not realizing until earlier today that it involved active crossovers etc.

As for the rest, duly noted.

F1nut

Even if you don't know how to quote, you should have the decency to mention those were the words from others, not yours. You plagiarized people too many times, even mixed them up all over.

Not only is he plagiarizing, he completely left out the part that indicates the person was talking about Totem speakers, not Polk LSi's.

(may be higher and Totem could likely let you know the exact spec).

Bernal

F1nut wrote: »

Not only is he plagiarizing, he completely left out the part that indicates the person was talking about Totem speakers, not Polk LSi's.

Only made ​​use of the words to express an idea applicable to the reference speaker Polk.
I do not consider it wrong, only use the expression of the idea.
6 ohms receiver used is not the best reference for a speaker of 4 ohms

F1nut

Bernal wrote: »

Only made ​​use of the words to express an idea applicable to the reference speaker Polk.
I do not consider it wrong, only use the expression of the idea.
6 ohms receiver used is not the best reference for a speaker of 4 ohms

Maybe you missed this,

dorokusai wrote: »

If I was running a pair of LSiM703, I wouldn't have any problem recommending them as they are compatible with 8ohm outputs per Polk documentation.

Regardless, I've looked at the specs for the SC-37 and it appears to be one a few AVR's that actually puts out its rated power with all channels driven. Although, it is not specifically rated to drive 4 ohm loads, I fail to see why it wouldn't.

Bernal

F1nut wrote: »

Regardless, I've looked at the specs for the SC-37 and it appears to be one a few AVR's that actually puts out its rated power with all channels driven. Although, it is not specifically rated to drive 4 ohm loads, I fail to see why it wouldn't.
Maybe you missed this,

dorokusai wrote: »

If I was running a pair of LSiM703, I wouldn't have any problem recommending them as they are compatible with 8ohm outputs per Polk documentation.

Ok. +1

And:

JimAckley wrote: »

...and are also more efficient than the LSi line.

Bernal wrote: »

This is a technical conclusion, and very good to know

stillen

OK then look forward to your input on the 707's.

pjdami

Thanks for the detailed review Jim. Very well written and thought out. You bridged the gap between any 'weaknesses' with the current LSi line and the LSiM. As an owner of LSi 15s for many years now (mostly HT use), I have long waited for an 'upgrade' from Polk. Can't wait to get my ears on some LSiMs.

RuSsMaN

Guys, keep it on track here, with the limited availability of LSiM right now, lets focus on the reviews and feedback. If you want to mix it up and discuss amps etc, let's do another thread. Thoughts?

Paul, I'm so happy to have you back in the fray.

magic12kenneth

After reading your reply, I really got excited. I'll have to add this one to my wish list:

Paradigm MilleniaOne Satellite Speakers
PSB Imagine Mini Bookshelf Speakers
Audience ClairAudient One Bookshelf Speakers (single driver, most natural speaker with a big too)
Polk Blackstone TL3 Satellite Speakers (TL2 was a little muddy on low volume)
Polk LSiM 703 Speakers (New)

How are the amplifier requirement to make them dance? I'll have to read up on the design what makes this so special.

JimAckley wrote: »

No matter high volume or low, the clarity is still there, the smoothness is still there, the midbass punch is still clean and tight. The thing that will surprise you most is how ridiculously smooth they sound. Everything about them is 100% pleasing to the ear. My only complaint in the whole review was that they didn't have the depth of modded LSi's, but keep in mind that modded LSi's set the bar pretty damn high.

mantis

EndersShadow wrote: »

Good to know. Would you still suggest dedicated amps since they can deliver more wattage than the AVR's can?

I would if you had a large room. The SC 7 series models have good reserve power and surprising dynamics. In small to medium size rooms with 4 ohm load speakers these receivers do very well. They crush large rooms with 8 ohm load speakers. I have done so many Mythos / SC theater and never once felt I needed more power.

If you are one to be watching and listening at reference levels all the time , then yeah adding an amp will be safer for both the receiver and the speakers. When I had the Rotel RMB1095 , it was very nice as it got out of the way for sound quality. At medium volumes you could not tell the difference when the amp was in the chain and when I removed it. Pretty sweet amp.

magic12kenneth

Jim, two more questions for you. How big is the sweet spot and off-axis listening? Reading from the technical paper, the bookshelf has three drivers integrated. How coherent are there? I'm pretty sensitive to this after owning a single driver speaker for desktop listening.