How much power? LSi 9

1hotsho

I am new to the home theater, but I have been doing alot of reviews on the LSi9 speakers and I would like these for my home theater system. Many posts have stated you need alot of power to make these speakers perform, so my question is, is there a stand alone receiver that would do these speakers justice or would a preamp and amp combo be better. For reference my room is 25'X16'W. I am putting in-ceiling speakers for the surrounds, the side/rear just won't work. Probably go with the LC80/60i? I am looking for receiver maybe in the $750-1000?

Ferres

If you intend to power lsi9's with a reciever get an HK brand.

sickicw

I bought some lsi9s about 6 months ago, and I will tell you my experiences. First of all they are 4 ohm speaker and the impedance can get down to 2 ohms. This means to get a flat frequency response from them (so they will sound as they were designed to), you will need an amp that can double its output from 4 ohms to 2 ohms. Most amps were designed for 8 ohms and don’t sound good at all with the lsi9s unless you have a good equalizer to flatten the response (and your amp has plenty of reserve power). Don’t bother with a receiver. If you are going to use a receiver, I would look into other speakers. Me, personally I tried the outlaw 755 and although it drove them, it couldn’t really didn’t take hold of the woofers and the sound was pretty thin. Then I did a little “do it yourself engineering” and bought a good car amplifier and a used 55 amp power supply and integrated one nice and cheap 2 channel amp able of dishing out 200 watts at 4 ohms and 400 watts at 8 ohms all for under $1000.

My new car amp sounds much, much, much better than the outlaw amp and I am very happy with it. I still haven’t decided if I am going to take the time to swap over all my home theater speakers to use Rockford Fosgate car amps (of course I will have to build some nice enclosures if I do this), or same up the money and get me a krell 3250.

Anyhoo, I guess to answer your question, you need lots of high current power that is stable down to 2 ohms if you want it to sound its best. Might also want to check out a sunfire amp. You can probably pick one up used for under $1000. But really it all depends on your tastes. If you are happy listening to the lsi9 with a high crossover setting on a less than idea amp, go for it and let your sub do all the work. Me personally, I want the lsi9s, to do the work down to 60hz. I bought those bad boys for a reason, and think it would be a waste to not use there full potential …..

McLoki

sickicw wrote:

Then I did a little “do it yourself engineering” and bought a good car amplifier and a used 55 amp power supply and integrated one nice and cheap 2 channel amp able of dishing out 200 watts at 4 ohms and 400 watts at 8 ohms all for under $1000.

Interesting solution to the problem. I have never heard of anyone doing this before. If you get a chance it would be an interesting read to hear more about the problem you were trying to solve and how your solution worked in comparison to the outlaw amp that many here seem to like. (as far as home amps go)

I don't know if I would try it - to many excellent amps in that price range that are designed for home use - but I am glad it worked for you and I wish I could hear the results sometime.

BTW - I bet it is 200 watts at 8 ohms and 400 watts at 4 ohms. (just to keep from confusing people - in a good amp the watts should increase by 50%-100% as the ohms (resistance) decreases.)

Michael

sickicw

McLoki wrote:

If you get a chance it would be an interesting read to hear more about the problem you were trying to solve and how your solution worked in comparison to the outlaw amp that many here seem to like. (as far as home amps go)

BTW - I bet it is 200 watts at 8 ohms and 400 watts at 4 ohms. (just to keep from confusing people - in a good amp the watts should increase by 50%-100% as the ohms (resistance) decreases.)

Yea, i might write it up and send some pics one of these days. I basicly wanted a high current amp that is designed for low impedances. Car speakers are 4 ohms, so it seemed like a no brainer...

the output for it was rated at 200 watts at 4 ohms, and 400 watts at 2.
It wasn't rated for 8 ohms, but i assume it is 100 watts.

steveinaz

My opinion is that Lsi9's should be reserved for seperates, with an amp minimum of 125 watts/channel, preferably 200watts/channel or more.

I'm not trying to be an audio snob, just telling you that the Lsi9 is a VERY demanding speaker on the amp. It can be a very rewarding speaker when ran "correctly."

Personally, If i were going to spend "Lsi9" money, I'd go Paradigm Ref Studio 40. But thats my opinion, and you know what they say about opinions...

polkatese

steveinaz wrote:

My opinion is that Lsi9's should be reserved for seperates, with an amp minimum of 125 watts/channel, preferably 200watts/channel or more.

I'm not trying to be an audio snob, just telling you that the Lsi9 is a VERY demanding speaker on the amp. It can be a very rewarding speaker when ran "correctly."

Right on, Steve. I would add it's true of LSi15 too. Now, what is this about Digm that you don't like about?

opus

steveinaz wrote:

My opinion is that Lsi9's should be reserved for seperates, with an amp minimum of 125 watts/channel, preferably 200watts/channel or more.

...

Steve, Would that be 125watts at 8 ohms? IYO

VR3

YOU NEED ALOT OF EFFING POWER!!!!!!! ALOT!!! ALOT!!! ALOT!!! SO MUCH YOUR BRAINS WILL SPILL ON THE DESK IN AMAZEMENT AT THE POWER NEEDED!

An amp STABLE at 4 ohms will adequately POWER the LSi9. Of course, the better the amp with more current will power them BETTER.

The Adcom GFA-535 would power the LSi9 just fine, but not to its capabilities.

NO RECEIVER (Mainstream) will power the LSi9 to its abilities. B&K, Rotel, Adcom, Outlaw, NAD, etc all have receivers that are capable.

tdeluce

polkatese wrote:

Right on, Steve. I would add it's true of LSi15 too. Now, what is this about Digm that you don't like about?

I agree but even more so with the LSi15s ( they have an additional 8 in.
unpowered woofer ). It wasn't until I turned on 600 watts to each of my
LSi15s and LSiC that I understood what I was missing. I am sure I don't use
anywhere near that most of time but it helps enormously when I drive
them hard or when a peak comes along...

polkatese

my magic number is 400 watts @ 4 ohms for the LSis...

markmarc

Steve:
I've heard the LSi9's and the Studio 40's and I have to agree with you on picking the 40's. My reasons are #1, that the 40's are smoother IMHO, across all frequencies. #2, they sound great with a wider variety of equipment.

As for using a car amp, its an intriguing idea, but I have to wonder about the S/N ratio as car amps don'y produce very "clean" sound from what I understand. Just my 2 cents.

steveinaz

opus wrote:

Steve, Would that be 125watts at 8 ohms? IYO

YES, bare minimum--and don't expect much.

The Lsi9 sits in a strange "niche." Most people who are running serious power (300watts/channel and above) aren't interested in driving bookshelf speakers. With that kind of power, why be limited by a bookshelf (my thinking), because of physical limitations in the small cabinet that cannot be overcome. Plus, with that kind of power costing you probably $1500 or more, you're gonna run a $1000 speaker? Just don't make sense to me. Polk should have built this series to be a little easier to drive, IMO they're just too "eccentric", for lack of a better term.

I would think the Lsi15 would actually be easier to drive because it doesn't have the extremely low impedance dips that the 9 displays--niether does the Lsi7, which might explain why many prefer the Lsi7 over the Lsi9. This is conjecture, as I've never heard the Lsi15 or 7, but I've seen the impedance curves of both.

McLoki

It is a speaker series that sounds good (I would say what you would expect for the price) with most upper end AVR's. (around $1000 price point)

The true value and worth of the speaker though will never be seen by those running AVR's. It is a decent speaker with decent electronics, but it just keeps getting better and better as you move up the audio food chain. I think that makes it a great transition speaker for budding audiophiles.

It will sound pretty good if you are starting with a decent AVR and will just keep sounding better and better as you upgrade your other components. It is a really nice mid-high end speaker series that will show the benefits of high end equipment while still being accessable on decent mid-fi gear. (at least not showing mid-fi flaws to the point of sounding like crap - aka it is pretty forgiving)

There are tons of people who have purchased the LSi series and think it sounds great running on denon, onkyo and yamaha AVR's. While I will agree with them on the sound, most owners of LSi speakers will never know what the LSi's are capable of and will, unfortunately, upgrade the speaker rather than the electronics to get a better sound.

Michael

2+2

tdeluce wrote:

It wasn't until I turned on 600 watts to each of my
LSi15s and LSiC that I understood what I was missing.

I can't hear you!!!!!....no more upgrades...no more upgrades....no more upgrades...no more upgrades....no more upgrades...no more upgrades...

McLoki

2+2 wrote:

I can't hear you!!!!!....no more upgrades...no more upgrades....no more upgrades...no more upgrades....no more upgrades...no more upgrades...

You don't have to listen to him. You don't need 600 watts to open up the LSi series, 500 is more than enough.

Michael

RuSsMaN

Ummm....Eighty Nine watts should do it. Yeah.

McLoki

In all seriousness, I really think current capability is much more important than watts for the LSi series to shine.

Michael

2+2

McLoki wrote:

In all seriousness, I really think current capability is much more important than watts for the LSi series to shine.

Michael

I think agree with you there....I liked my LSi15s better with an HK 80W amp than a Rotel 120W amp, HK having higher instantaneous current capability than the Rotel :eek: ..... My LSi 15s will just have to settle for the 200W Rotel I am giving it now...I am not going to give it more!

McLoki

2+2 wrote:

My LSi 15s will just have to settle for the 200W Rotel I am giving it now...I am not going to give it more!

But you know you want to..... :cool: :cool: :cool: :cool:

Michael

steveinaz

The ability to drive extremely low impedances is #1, IMO, however that is achieved. I didn't have to push my HCA-1500 (215 watts) that far to get loud, but either the Lsi9 was beginning to compress its dynamics OR my HCA was running out low impedance steam...don't know which, based on how the speaker sounded, I suspect the former.

scottnbnj

steve, from your review thread, it looks like y'all had alot of fun with those lsi9's and really had them shaking. everything you mentioned fit into what i've heard from mine at one time or another, though i can't say i've ever seen my drivers work as hard as what you described. but then, my room is smaller and my uh,'the receiver' obviously has alot less grunt.

in any case, considering the force you were propelling those 9's at, your demo would have benefited greatly from spiking those suckers to the floor. i gotta think that that might have influenced what you heard when you were really juicing them up.

thanks again for your review in the other thread.

)

steveinaz

True Scott about the spiking, I hadn't considered that. I didn't have any decent stands available so I used 2 bar stools, which happened to place the tweeters just perfectly at ear level.

I didn't want to harp on the power issue too much as the Lsi9's played PLENTY loud for most anyone, and certainly louder than any other bookshelf I've heard.

scottnbnj

heh. heh. you should see some of the shi..,uh,stuff i had mine stacked on before i decided what height stands to get. that sticking to the tweets could have been another thing that not spiking might affect too, not soley, i've heard it other times too, but, partly.

)

lanion

I have a HK DPR 1001 I use to drive my LSI9s and I think it sounds good, but I certainly want a new amp. The DPR puts out 50watts/channel into 8 ohms and 50/watts channel into 4ohms, so its really not high current at all. At times it sounds fantastic, other times not so great. I just want to get away from amps that have a 4ohm / 6ohm / 8 ohm switch.... it sounds so much better when set to 8ohms, but it worries me when I do that.

steveinaz

Lanion
If I were to buy a set of Lsi9's, I'd be hitting the 'gon or ebay looking for Carver M-1.5T. There's 2 of them right now on the bay...

lanion

Im gonna get something from Outlaw soon.

SKsolutions

IT'S ALL IN THE CAPS.! Literally. Transformer fills em, speaker drains em. Current capability is equal to quick power from the supply to the caps and through the output transistors with out frying em. The load presented by the 9's is complex and very near a dead short in certain frequency ranges 200ish. There is also the damping and negative feedback factors of the amp that contribute to control of the drivers, and thus the sound that is generated. I am currently (pun intended), driving my 9's very well with a 75 watt amp that will peak at 135 ish with less than 1% THD into an 8Ohm load. The same amp will deliver around twice that into a 4 Ohm load.
So, to those who say you need a ton of power.....you are correct....in a sense. You just need to have it when you need it (deep passage and when the impedance drops across the frequency range).
IMO Philips

beardog03

My Parasound HCA-3500 drives them nicely..

I`ll let ya know how the Cary V-12 mono`s do in about 6 months..

Mazeroth

I may get bashed but I'm going to try to help some guys that aren't familiar with how speakers work.

Watts = Volume...nothing more.

Some people are under the impression that more watts = tighter control over the speaker drivers, better separation etc...that's absolute nonsense. I'm not trying to sound like a jerk here but for the last 1.5 years I've devoted at least 1-2 hours per day reading and experimenting with loudspeaker design, and have learned a TON. A lot of the stuff I thought to be true, before getting into loudspeaker design, wasn't. With that...

The LSi9s will play just fine with a receiver, GRANTED, you don't listen to them at extremely loud volumes. When you double power, you gain 3db in output, PERIOD. Not better control, not better separation, just 3db. Yes, having an amp with greater headroom means the amp will be less likely to clip, which will give you better sound quality, but if you listen at a reasonable level, a 50-100w @4 ohm amp will be more than sufficient.

Polk rates the LSi9 at 88db/1w/1m efficient. When you 10x power, you gain 10db. Therefore, the LSi9 will play at 98db/10w at 1 meter listening distance. When you double distance, you lose 6db (almost always). At 2 meters, you'll have a speaker playing at 92db, which is LOUD. At 4 meters, that speaker will be playing at 86db. 86db is a pretty good number, considering you're only throwing 10 watts at the LSi9. Oh, and I forgot to mention, that is only for one speaker. Let's throw 10 watts at the other one, which gives us a 6db increase in output since we're doubling our power and number of speakers. Now, with dual LSi9s, each getting 10 watts, you're getting 92db of volume at 4 meters! Drop back another 4 meters, which I doubt anyone listens at 8 meters, and you're still getting 86db of output! Double the power to 20w, and you're at 89db. Double that to 40w, which any HK receiver can do (I had an AVR230 on LSi9s and it was great), and you have 92db of output at 8 meters, or for most people who listen around 4 meters, 98db, which is extremely loud:

http://www.schoolscience.co.uk/content/4/physics/corus/sound/psch1pg3.html

Sorry for going on so long, but I'm an advocate of not needing a ton of power. The line arrays I built are 98db/1w efficient, and I had them running off a Sonic Impact T-Amp, with the gain about 1/4 the way up and they would drive people out of the room with about 2 watts of power. The tube guys can attest to how little power is truly needed.

I say save your money and get a beefy HK, NAD, Outlaw etc. receiver and call it a day.

wingnut4772

Thanks Mazeroth...that was actually pretty enlightening.