LSI15's Do I really need an amp?

[adjutant]

First off let me say, incredible site! I have spent countless hours here for the last 2 weeks, and have decided on/purchased a pair of LSI15's and an LSIC. The receiver I have driving these three speakers is a Yammy rx-v757.

Now, I have read countless posts that say Polks draw alot of power to perform well. I want to know will my speakers performance suffer without the added amp? I really dont care about barely discernable differences, I mean will it be a WHOLE different world with an amp. I'm not planning on "blasting" these speakers. I just want a full, true sound

Thanks in advance for you help on this.

PS. It seems like 12 gauge wires are the way to go. Any suggestions?

 

[cbraver]

I wouldn't say Monster Cables are a "bit hit" here, but they will do fine.

For RCAs:
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=175775&is=REG

For speaker wire:
I use either cat5 cable with Cordas terminators or Comprehensive speaker cable (you can also get that bhphotovideo.com ...although I buy it elsewhere locally).

-Chad

 

[jaxvon]

For speaker cable, if you already have some 12ga stuff, then that's fine. Otherwise, you might want to check into grabbing some Belden 5000 series stuff from Westlake Electronic.

Monster makes quality stuff, but it's overpriced as hell.

 

[Buckeyefan 1]

First off let me say, incredible site! I have spent countless hours here for the last 2 weeks, and have decided on/purchased a pair of LSI15's and an LSIC. The receiver I have driving these three speakers is a Yammy rx-v757.

Now, I have read countless posts that say Polks draw alot of power to perform well. I want to know will my speakers performance suffer without the added amp? I really dont care about barely discernable differences, I mean will it be a WHOLE different world with an amp. I'm not planning on "blasting" these speakers. I just want a full, true sound

Thanks in advance for you help on this.

PS. It seems like 12 gauge wires are the way to go. Any suggestions?

Your Yammy will drive the LSi's, but members here who own them will tell you those speakers won't "wake up" until you add a separate amp, or at least bi-amp the LSi's. You can get inexpensive two channel amps off ebay to do the trick for under $200. Those speakers are rated at 4 ohms. Make sure your receiver can handle the load. This may or may not help:

www.gcaudio.com/resources/howtos/voltageloudness.html

Did you get a chance to read the reviews at Polkaudio.com on the LSi15's?

www.polkaudio.com/home/library/reviews/customers.php?category=25&speaker=165

12 ga. wire from Home Depot is all you need for speaker wire. If you need more than 50 ft of run, go 10 ga. 12 ga. wire at HD is around .20 cents a foot.

 

[Nick250]

First off let me say, incredible site! I have spent countless hours here for the last 2 weeks, and have decided on/purchased a pair of LSI15's and an LSIC. The receiver I have driving these three speakers is a Yammy rx-v757.

Now, I have read countless posts that say Polks draw alot of power to perform well. I want to know will my speakers performance suffer without the added amp? I really dont care about barely discernable differences, I mean will it be a WHOLE different world with an amp. I'm not planning on "blasting" these speakers. I just want a full, true sound

Thanks in advance for you help on this.

PS. It seems like 12 gauge wires are the way to go. Any suggestions?

I am squarely in the barely discernable to no benefit at all side of things. I think there is often alot of placebo effect with the exteral amps.

 

[anamorphic96]

Get the exteranl amp. Polk LSI's draw alot of current. I like Yamaha receivers but it wont even get you close to what the LSI's are capable of. Spend the extra 2 to 400 and get yourself the amp.

What you will notice with the seperate amp is tighter deeper bass. Dynamics will be handled with greater ease especially when peaks can hit 90 and 100 db.

Parasound, Rotel, NAD, Parasound,and Adcom all offer great used amps.

As stated above some dont hear the difference. But every speaker I have hooked a seperate amp up to made noticeable differences. Especially the upper end lines like the LSI's which are capable of better resolution.

Cheers,
Glenn

 

[zumbo]

An amp will make a difference. But, not in loudness. The more you crank the volume, the more the sound comes to life and remains detailed. Right now, the more you crank the volume, the quality of the sound diminishes. Also, your Yamaha will be dead soon trying to drive 4ohm speakers. I have 4ohm speakers. I use Adcom.

 

[20to20K]

It makes a difference...sort of.

I owned my LSi15's for about 6 months before I decided to buy a seperate amp. I initially did it more just to take the strain off my Denon 3805 than to expect a huge difference in sound. When I added the LSi C (as you have too) and my two rears I figured driving that many 4-ohm loads is not a good idea for a receiver that doesn't recommend even one speaker rated lower than 6 ohms. I think most Yammies have a 4ohm/8ohm switch...I don't know if your model does or not.

My equipment is inside an enclosed oak entertainment center and when my Denon was driving all 5 speakers it would get noticibly warmer...it never cut off on me, but for the cost of an outboard amp it was worth protecting my precious AVR. The way my system is setup up, if I left my glass door on my entertainment center open it would block my left/front speaker.

I initially bought a used Denon 2400 (200x2 @ 8ohms) off Ebay for $350 that sounded great and did the job until one of the channels blew not too long after I bought it. I eventually had it fixed, but in the meantime One Call had a clearance sale on a brand new ATI 1502 (150 Watts/channel) for $399.

After I got the Denon back from service I did plenty of A/B/C testing between having the Polks driven by the 2 amps and the 3805 and found that while there were not noticible differences in sound quality at "normal" listening levels, when I really cranked up the music to unreasonable levels, either of the amps made the Polks sound clearer...I felt as though I could even detect distortion in the 3805 at these levels. I have to admit that I would never be able to listen to music this loud unless the house was completely empty (as it was whenever I did any of these comparison tests), but that is what I found to be true.

When I drove them with the 3805 at this level it got concernibly hot during the testing and neither of the amps were even warm to the touch. That alone made it a worthwhile decision.

I'm currently using the ATI to drive the LSi15's and the Denon to drive the center and my sub(bypassing the internal amp). Now the 3805 only has to drive the rears (fxi3) and now IT never even gets warm to the touch.

I would recommend you go with your current setup for now and see how your Yamaha performs...both sound wise and how hot it gets. If your receiver is in a position where it can breathe you may not experience my problems and you could be O.K. It sounds like you don't "blast" your music so the difference in sound at high SPLs may not be a problem either. The difference in power between our two AVRs is insignificant (100 vs. 120) so you should be O.K.

Good Luck!

 

[adjutant]

Thanks for all the great input! I am going to just field test everything now and subjectively evaluate the quality of sound at my listening levels, as well as monitor the receiver to see if it seems to be stressed (warming up).

I have researched the hell out of these components and after spending the kind of money I have, want the best sound possible.

I never really thought you could truly tell differences in sound but listening to the RTi12's, LSi15's, and Martin Logans (hell they were there to listen to!) I could hear big leaps in sound from one system to the next.

I look forward to continuing my research and growth on this board. It really is an amazing site

 

[sjdgpt]

I would not bother with an external amp.

By the way, I kept a NAD amp from my old system just in case I needed it. I haven't needed, and to be honest, it actually is detrimental to the sound of my system.

System:

Polk LSI-9's and LSI-C on the front, 7's on the rear.
Denon AVR 2805 100wpc yada yada yada.

I have had the volume at above the 0 setting more than once.

Yes the Denon gets warm. It is suppose to!

By the way, the Denon gets almost as hot if you leave the unit on over night. On meaning not in the powered down standby mode.


Yes the 15's have the built in "sub woofer". Basically it is just an 8" woofer. Yes there is a lot of energy required for the woofer, but it is not that great that your Yammy can't handle it.


To get a real improvement by adding an external amp you would have to double the power to get just a 3db barely audible improvement.



Why is my NAD detrimental to the sound quality? It isn't power. The NAD has plenty of that. It is the additional set of RCA cables, an additional power cord, a few extra circuits etc that is creating just a weeee bit of floor noise (also known as white noise or background hiss). I suspect the age of the NAD has a lot to do with the additional noise.... the newer equipment has such better SN rations compared to much of the old equipment.


If I really "needed" the extra power, I would purchase a NEW multichannel amp and use the Yamma as a prepro only.