Reveiver + amps to go with LSi system

spphoenix

I am in the process of putting together an LSi speaker system.

2 LSi 15s
2 LSi 9s
1 LSiC
2 LC80i (Might not need these)

Originally, I was simply planning on using these with a Denon AVR 1912, but was told repeatedly that it wouldn't get the job done, and the receiver and/or speakers could get damaged. So, after being educated on separate amps, I am now looking for a receiver with preouts around the $500 price range. One of the other members here recommended I start with the following for the fronts:

Pioneer VSX-1121-K 7.1-Channel A/V Receiver

paired with:
adcom gfa 545 or 555

and build from there. I was wondering if you guys had any other suggestions or comments?

Thanks for any help you can provide.

cnh

You're going to need, at minimum, a 5 channel amp. So you should look at offerings from Adcom, Parasound, NAD, Rotel, etc. for 5 channels. Example Adcom GFA-7705 (200 Watts x 5). Or Parasound HCT-2205AT or 2205A (220 Watts x 5), etc.


cnh

pyrocyborg

I support what cnh said. I wouldn't try driving a 4 ohm speakers pair with a receiver though... Do you really need 7 speakers, or you could get the job's done with 5?

spphoenix

Oh no no, the receiver is just for a front end. everything is going to be driven by the amps. and I might forgo the in ceiling

rooftop59

There are lots of suggestions about this on the forum; this is a topic that has been discussed many times and that is why I think that you are not getting too many responses. Check out these links:

http://www.polkaudio.com/forums/show...48#post1740348

http://www.polkaudio.com/forums/show...heater-Project

tonyb

spphoenix wrote: »

Oh no no, the receiver is just for a front end. everything is going to be driven by the amps. and I might forgo the in ceiling

The amps you mentioned in your original post are only 2 channel amps, good for 2 speakers, you'll need more amps or one 5 channel amp.

hertz9753

If you don't have dedicated 20 amp circuit I would not go with a 200w x 5 channel amp.

BlueFox

hertz9753 wrote: »

If you don't have dedicated 20 amp circuit I would not go with a 200w x 5 channel amp.

I doubt if that is true. I run my HT, 4 LSi15s and a PSB Synchrony one center, with a Sunfire TGA-5400 on a 15 amp circuit, along with the TV, sub, AVR pre-pro and Blue-ray player all on the same circuit with no issues. In fact the AVR, Blue-ray, and amp are plugged into a Panamax power conditioner that has both a voltage and amp meter on it. The amp meter has never exceeded 2 amps, even while blasting. Granted, the Sunfire is efficient, but I doubt if other 5 channels are so inefficient that a 20 amp circuit is needed.

spphoenix

Originally I was considering finding some used 2 channel or 3 channel amps, but these thing seem to keep there value fairly well and for these speakers I'm thinking I want something with a minimum of 200W/ Ch at 4 ohm, and preferably 300.

So now I'm considering just biting the bullet and going for a 5 channel amp. The Emotiva XPA-5 looks like it can fit my budget, and other users seem to be happy with it. Could I drive a 5 speaker LSi system on that comfortably?

hertz9753

http://www.adcom-usa.com/userguides/gfa-7705-ug.pdf

I love Adcom and will admit that is at max.

IRLRaceFan

cnh wrote: »

You're going to need, at minimum, a 5 channel amp. So you should look at offerings from Adcom, Parasound, NAD, Rotel, etc. for 5 channels. Example Adcom GFA-7705 (200 Watts x 5). Or Parasound HCT-2205AT or 2205A (220 Watts x 5), etc.


cnh

Parasound HCA-2205A(T) is a great choice for your speakers - I have one & am really happy with it.
I also don't have on a 20amp circuit & have no issues.

tonyb

spphoenix wrote: »

Originally I was considering finding some used 2 channel or 3 channel amps, but these thing seem to keep there value fairly well and for these speakers I'm thinking I want something with a minimum of 200W/ Ch at 4 ohm, and preferably 300.

So now I'm considering just biting the bullet and going for a 5 channel amp. The Emotiva XPA-5 looks like it can fit my budget, and other users seem to be happy with it. Could I drive a 5 speaker LSi system on that comfortably?

Yes, that will work fine. If you want to save some coin, you could also look at used amps. My first choice would be B&K amps, more musical sounding.

On a side note, don't think watts, think current. LSI's being the 4ohm speakers they are, love current.

cfrizz

spphoenix wrote: »

Originally I was considering finding some used 2 channel or 3 channel amps, but these thing seem to keep there value fairly well and for these speakers I'm thinking I want something with a minimum of 200W/ Ch at 4 ohm, and preferably 300.

So now I'm considering just biting the bullet and going for a 5 channel amp. The Emotiva XPA-5 looks like it can fit my budget, and other users seem to be happy with it. Could I drive a 5 speaker LSi system on that comfortably?

The Emotiva will do just fine and give the speakers the power they need to operate to their full potential. You are putting together a great system! Welcome to Club Polk.

PSOVLSK

Here's my take on the Emo vs. the NAD T-955: http://www.polkaudio.com/forums/showthread.php?130661-My-new-amp-vs-my-old-amp

Very comparable with a slight edge to the NAD and it costs $100 less.

www.audioadvisor.com

I was just went throught the process you're going through and this amp made the most sense to me. YMMV.

Check here if you haven't already done so: www.audiogon.com Parasound, Rotel, Adcom, B&K, Outlaw, et al. Good luck in your search.

spphoenix

I'm going to go off on a tangent below but before I do, I haven't heard anyone mention the VXI-1121. Based on when I was considering using the Denon 1912 and got a lot of concerned posts, I'm assuming no one saying anything means it's ok, but if someone could say "you will be happy with this receiver", it would make me feel better about buying it this weekend.

Also, I wasn't seeing anything on audigon in the 200 - 300Watt 5ch price range that wasn't above $500 and 10 years old. I figured spending the extra $300 for a brand new amp made more sense. Flawed thinking?

Now, on to the tangent. It's interesting that you bring up current. I would almost think that would be an afterthought. Here is my thinking, please let me know if it's wrong (haven't done power in a while, and speakers are foreign to me):

P=V*I
P=(I*R)*I
P=(I^2)*R
sqrt(P/R)=I

The power of your amp isn't going to change (you would hope). Your resistance is going to fluctuate with frequency, but on average it's going to be hovering around the nominal impedance of your speakers. So you would expect that at the very least your amp would be able to provide the current demanded at, in this case, 4 ohms for whatever power it is rated at. The more power your amp is expected to provide, the more current it would be expected to provide. I figure the two would go hand in hand, which is why I wasn't even thinking about it. More power = more current. Is this wrong?

tonyb

You can't drive LSI's with the 1121, plain and simple. You'll need an amp, but like everything in audio, they vary in sound quality, power, price. Throw out a budget and we can point you towards good amps. If your decision is based on warranty over sound quality, then yes, Emotiva would be the place to start. Not saying the Emo is bad as it would power the speakers fine, but there are better ones out there with better sound quality.

Current is what receivers lack and amplifiers excell at. Watts doesn't necessarily equate to current. A 50 watt tube amp can have more current that a 100 watt SS amp. Don't get so caught up in the numbers, think of a budget and we'll try and give you your options as best we can to ensure you enjoy the speakers.

spphoenix

No no, the receiver is only for the front end interface. Basically I am looking for a good $500 receiver with preouts, and was wondering if the VSX-1121 would fit that bill? The speakers will be run off of whatever 5 ch amp I buy. I'm willing to pay $1000 for an amp but less would be better.

tonyb

Gotcha....5 channel amps of decent quality will be hard pressed to find under 7-8 hundies, even thats a challenge. Keep an eye on Audiogon, craigslist, and our own FM, when deals come up they go fairly quick.

spphoenix

Which was the impression I was getting. Which is why I was considering going for either the Nad t-955 or the Emo.

But actually I just stumbled on this guy on audiogone:

Sunfire Cinema Grand 5 Channel amplifier
One for $975 and another for $100 (seems like a rather large difference?!). Any comments on him?
Here are the links:
http://app.audiogon.com/listings/sunfire-cinema-grand-5-channel-amplifier--2
http://app.audiogon.com/listings/sunfire-cinema-grand-5-x-200-front-panel-new

gdpeck

spphoenix wrote: »

Which was the impression I was getting. Which is why I was considering going for either the Nad t-955 or the Emo.

But actually I just stumbled on this guy on audiogone:

Sunfire Cinema Grand 5 Channel amplifier
One for $975 and another for $100 (seems like a rather large difference?!). Any comments on him?
Here are the links:
http://app.audiogon.com/listings/sunfire-cinema-grand-5-channel-amplifier--2
http://app.audiogon.com/listings/sunfire-cinema-grand-5-x-200-front-panel-new

The hundred dollar listing is just for the front panel. It isn't a complete amplifier. Someone else will have to comment on the amp itself, as I have no experience with it.

spphoenix

And tony mentioned B&K, which I also found on audiogon. It's for $1350, a little more than I wanted but if it's worth I might go for this one. Comments?

B&K Reference 200.7

PSOVLSK

I've heard good things about both the Sunfire and the B&K, but I've heard them personally. There are a few members here who use them so maybe they will chime in.

I think the Pio would be a fine pre. Or there is a B&K Ref 50 in the FM for a great price. http://www.polkaudio.com/forums/showthread.php?129860-B-amp-K-Ref-50 If you need HDMI, etc. it wouldn't work for you, but otherwise a great piece at a great price.

cfrizz

Get whichever receiver that has all the bells and whistles that you want it to have & make sure it has preouts, or as Psovlsk pointed out get the preprocessor in the fleamarket that would be awesome as well!

I have a Sunfire 5 channel 405wpc amp, (see signature below) I LOVE it. It is one of the few at the time that I can lift without breaking my back. That is a terrific price and will drive just about any speaker with ease. You should jump on it.

That B&K will also get the job done. As you are finding out, you have quite a few options on the used market.

nwohlford

spphoenix wrote: »

I'm going to go off on a tangent below but before I do, I haven't heard anyone mention the VXI-1121. Based on when I was considering using the Denon 1912 and got a lot of concerned posts, I'm assuming no one saying anything means it's ok, but if someone could say "you will be happy with this receiver", it would make me feel better about buying it this weekend.

Also, I wasn't seeing anything on audigon in the 200 - 300Watt 5ch price range that wasn't above $500 and 10 years old. I figured spending the extra $300 for a brand new amp made more sense. Flawed thinking?

Now, on to the tangent. It's interesting that you bring up current. I would almost think that would be an afterthought. Here is my thinking, please let me know if it's wrong (haven't done power in a while, and speakers are foreign to me):

P=V*I
P=(I*R)*I
P=(I^2)*R
sqrt(P/R)=I

The power of your amp isn't going to change (you would hope). Your resistance is going to fluctuate with frequency, but on average it's going to be hovering around the nominal impedance of your speakers. So you would expect that at the very least your amp would be able to provide the current demanded at, in this case, 4 ohms for whatever power it is rated at. The more power your amp is expected to provide, the more current it would be expected to provide. I figure the two would go hand in hand, which is why I wasn't even thinking about it. More power = more current. Is this wrong?

I would think of amplifier more as something that amplifies the voltage. There is a certain input voltage with a gain applied by the amplifier. The amplifier always supplies the same gain to the input voltage with the volume control on the preamp modifying the input voltage. The impedance of the circuit (mostly the speakers) will decide the current needed. The power rating of an amp is just a measurement of when the amp can no longer supply the needed voltage or current under some standard (i.e., the %thd). Two amplifiers with the same power rating for 8 ohms may have different gains. At 4 ohms the ability of an amp to supply enough current is often the limiting factor (at higher impedances the limiting factor will often be the maximum output voltage that can supplied by the amp). Any real world speaker often has impedance dips at certain frequencies that can make current an issue for even speakers rated as nominally 8 ohms.

spphoenix

Out of curiosity, how old is too old for a used amp? The sunfire I posted above was released in '96, not to say it's 16 years old but it's probably at least 10. No clue how well these things age.

tonyb

Don't just go by a release date, go by the manufactured date. Some amps stay in production for years on end with the same name but different versions/series. Generally speaking, around the 15-20 year mark, caps will start needing replacing.

spphoenix

Just wanted to let you guys know I ended up pulling the trigger on a new NAD T955 for the amp. I figure I can always sell it later if (we all know its when) I want to upgrade it. Thanks all for the help, I would have been stuck with an under-powered receiver and terrible sounding speakers if it wasn't for you guys.

If anyone is looking to unload an LSiC or LSi9s (ebony) let me know. Thanks again all.

rooftop59

Hard to beat 500 shipped even on the used market. And polk has great customer service:

http://www.ebay.com/itm/PAIR-LSi9-Ebony-Bookshelf-Loudspeakers-Polk-Audio-/390320715539?pt=Speakers_Subwoofers&hash=item5ae0ed7713