LSI15 Wiring Question

Sax · July 2010

I believe the LSI25's have a powered subwoofer, and while I'm looking to upgrade at some point from my RTA11's I was not wanting to have a powered subwoofer.

My question about the LSi15's, are they completely passive? Or is their onboard subwoofer powered? If so can it be bypassed?

How do you guys tend to hook these up, bi-wiring? Amp considerations? I have currently an Adcom GFA-545II That I was planning on powering them with should I get them.

I know these are probably silly questions but, I've looked and cannot find a picture of the rear panel of an lsi15 for the life of me, nor have I found them on display anywhere (fry's, etc).

kawizx9r · July 2010

The side firing woofer is passive.

-Freddy

Sax · July 2010

Cool, thanks for that. Now I'm sold, definitely in the market for some LSi15's

cheddar · July 2010

I think you're definitely on the right track with the 15s. One of the best advantages to good external amplification is how it tightens up and increases the bass output. Going from a Denon mid level AVR to an external amp really woke up the woofers in my LSi 15s.

bld · July 2010

I use 2 channels per speaker,one each for the highs and lows,my amp is 800watts @ 4 ohms,per channel and these speakers handle like they mean it.Now i am not sure if the impedance on them is still 4 ohms when bi-amped,or if they are 4 ohm only when the highs and lows are on the same channel,maybe someone has the answer to that.good luck hope you like them,make sure side firing is really what you want,I found that they sent bass to the corners of the room,the very place we are trying to clean up(with traps),otherwise they are performers for sure.

Sax · July 2010

From a pure audiophile type stand point, yeah the side firing may not be ideal, but otherwise just in some demo setup at Fry's Electronics they were the best speakers I've heard for the money.

At any rate, the trigger has been pulled. I just won a pair NIB on ebay for $1350 including shipping

They won't be bi-amped for a while as I only have 1 amp, an Adcom GFA-545II. I'm thinking I could probably what, just get a 2nd one even? use one 545 for the bass and one for the highs? My preamp (B&K Sonata MC-101) has two outputs, I imagine for this very type of setup? Correct me if I'm wrong.

Anyhow, can't wait for them to get here either way!

PSOVLSK · July 2010

Sax wrote: »

I'm thinking I could probably what, just get a 2nd one even? use one 545 for the bass and one for the highs? My preamp (B&K Sonata MC-101) has two outputs, I imagine for this very type of setup? Correct me if I'm wrong.

Anyhow, can't wait for them to get here either way!

You are correct.

Enjoy the new speakers.

RelayerCR · July 2010

I use an amplifier Parasound Classic 2125. 125 watts in 8 ohmn, 200 watts in 4 ohmn.

I've been testing my new LSi15 bi-ampling with my Parasound: using speakers A for bass and speaker B for highs (bi-amp and bi-wiring). I don't know if this change the impedance of the amp, I don't have idea.

So I tried only bi-wiring, using only the speakers A binding post. The results are very similar, almost the same. However my speakers are new, a few hours of usage. I think I need at least one month for burning in and then I could test againg to find differences (¡my amp new, only one month old, so, ....!).

This amp works very easy, keeps warm, ..., I think that I have more then enough power.

My system:

- Polk LSi15
- Parasound 2125 amplifier
- NAD Stereo Integrated Amplifier C340 (used as pre-amp, hope to upgrade to Parasound Halo P3 soon)
- Cambridge Audio Azur 550C CD player (used as transport)
- Cambridge Audio DAC (DacMagic with two wolfson dacs, 24 bit)
- Speakers cables: 2 pairs of kimber 4vs (upgrading to 4TS soon)
- Interconnects by DH-Labs (Q-10)
- Digital cable Audioquest (silver solid)

cokewithvanilla · July 2010

RelayerCR wrote: »

I use an amplifier Parasound Classic 2125. 125 watts in 8 ohmn, 200 watts in 4 ohmn.

I've been testing my new LSi15 bi-ampling with my Parasound: using speakers A for bass and speaker B for highs (bi-amp and bi-wiring). I don't know if this change the impedance of the amp, I don't have idea.

I am curious to know how biamping is with the Lsi15s. Having the 25's, I lose that option and have always been curious. What other amp are you using to biamp with?

I have biwired with my GFA 5800 which has 4 binding posts per channel, and have noticed no difference at all.

RelayerCR · July 2010

Well in fact, I am not REALLY bi-ampling, because I'm using only one amp. My amp has two sets of binding posts (speakers A and speakers

. I just conect the highs freq. to one set of binding post, and I connect the low freq. to the other set of binding post.

I'm sorry, I think that I am abusing the language, using an incorrect description of what I'm doing.

Parasound 2125 has 8 binding post (is a normal amp with A and B speakers!):
- Speakers A has two binding post for the left and two for the right (positive and negative)
- Speakers B has two binding post for the left and two for the right (positive and negative)

:-(

Sax · July 2010

Thanks for the feedback you guys! My LSI15's get here tomorrow per my tracking number.

They wont' be bi-amped for a little while but I'm shopping around for a 2nd Adcom 545II, I like it so I figure I might as well just get a 2nd one and match them that way.

I figure the only way to go from there is probably to get Tube Amps perhaps? I was thinking some McIntosh MC275's down the road as I don't have that cash just laying around

.

Anybody have ideas/feedback to that? Ever power the LSI15's with Tube?

RelayerCR · July 2010

¿What cables, brand and model, do you use with your LSI speakers?

I've tried Kimber 4vs (2 sets, bi-wiring), DH-Labs Q-10 (bi-wiring), and I'm waiting for tow sets of Kimber 4TC (to bi-wire).

Betwen the kimber 4vs and the DH-Labs, the Labs sounded a little clearer and with more image (better definition). The difference is noticeable, but is noty dramatic.

When I receive and break-in and finally test the 4TC's I'll let you waht I hear.

My system: Parasound Amp/Nad pre/Cambridge Audio CD player+external DAC/DH-Labs, Kimber and Audioquest cables

Sax · July 2010

Just got my LSI15's today, fedex delivered them without a scratch. I barely was able to listen to an album through and I had to go to work though.

So far I love these things though!

RelayerCR - so far I'm just using some generic 10guage copper wire. My next round of upgrades does include wire, I'm likely going the zebra and/or bluejean cables route based off price/performance reviews I've seen.

Maximus666 · August 2010

Sax, I have really enjoyed my LSI-15's over the last several years. I hope you enjoy yours too.

Not only are they visually attractive, but they've got two pretty heavy and I think reasonably stiff mid drivers. And the sound's pretty good. (Yeah, I don't call myself an Audiophile, although I have read the articles and forums, and have gone to some expos, etc. My B&W/McIntosh oriented friend doesn't differ too much with my pronouncement, although he points out that the B&W sound is more airy. The highs do seem to be higher from those diamond tweets, after all.)

I think having sufficient power from an amp will provide years of enjoyment for you. I've read that the rule of thumb is 200WPC into 8 ohms, so possibly 300W into 4 ohms (but don't quote me on those numbers). It also helps to have sufficient guage of speaker wire, which as you pointed out is currently 10 in your case. I switch between some Kimber braided and 10guage lamp cord, based not on sound quality but on room configuration. I can't really tell the difference between them.

For what it's worth I have run my LSI-15's single-amped (and so bi-wiring didn't matter there). I think that as long as you have an amp that can source enough current for those hungry beasties (4 ohm nominal, down to 2 ohm or lower), and sufficient conductor for that signal, then you'll do well. (Had my fun with Bob Carver's designs up until I sold them recently.) I've seen the crossover schematic (search for "lsi15 schematic", there's a PDF floating around) and so it says that the tweeter is one input, and the rest are the other input. So I'm not sure if bi-amping will give conclusive gains.

Additionally, I've run them from the outputs of a Marantz receiver (6 channels, 120WPC supposedly... yeah, right), and always found the sound "restrained". Heheh... could never get that really good bottom-end response from Fairies Wear Boots (Black Sabbath). Or from Porcupine Tree for that matter, or Radiohead, ELP, or anything really.

Now I'm running them from an Emotiva XPA-5 (still the Marantz as pre). This 5-channel amp is rated at 300W RMS per channel into 4 ohms, with 6 output devices per channel backed by a power supply based on a 1200VA transformer. I'm quite happy with that until my next upgrade.

I think I wouldn't run full tube due to the low sensitivity of the LSI-15, and also because of the low efficiency of the amps. Possibly a hybrid amp, with tub front end and solid-state output. Or perhaps inserting a tube line amp between the preamp unit and the amp unit.

Hope you enjoy!

jmos · September 2010

Gday, I have just ordered some extra cables and connections to try passivly biamping my LSI15's.
I have the Lsi15s, LsiC, 4 X LsiFX. Using Onkyo 875, Cambridge Audio 840A(ht bypass), Elektra Theatre HD 7 channel PA.
Intend on splitting my pre outs on my 2 channel pre amp and using 4 outputs from my 7 channel PA to my lsi15's(removing the jumpers), Onkyo will pickup rear surrounds.
I guess I am not truely biamping as all I'm doing is separating the same input signal but doubleing the power output.
My PA outputs approx 390w@4ohms so I will now will be delivering potentially 780w@4ohms(I think thats how it works?)
What do you guys think, will the extra power and separation of signal alone possibly improve the sound quality, will soon find out but interested in your thoughts and experiences.
Regards
John

LSI15 Wiring Question

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