LFR1100 amplifier suggestions

Posted by: 7800

LFR1100 amplifier suggestions - 05/25/15 10:37 PM

Hi owners. First post on forum. I have my speakers set up in a 12x15 room hooked up to an Arcam P777 also powering my VP180HP and 2 QS8's. Home theatre sound is unlimited as I have an SVS13SB sub involved. I am wondering what the benefits are of going with more than 270w to the LFR's for a stereo benefit. Anyone running lots of watts?
Posted by: AAAA

Re: LFR1100 amplifier suggestions - 05/26/15 04:53 AM

Going to pro amps? Ie Crown, QSC. Your room is smallish and you are already in great headroom territory. Your P777 is beyond the realm of question when it comes to quality/performance. Improvements in your setup will now come from decreasing room RT60 to gain better perceived dynamics, assuming your room is untreated. You have maxed out your potential for what gear can offer you in your room I'm guessing.
Posted by: MatManhasgone

Re: LFR1100 amplifier suggestions - 05/26/15 06:17 AM

I have a pair of LFR1100 and have it hooked up to an Anthem MCA5ii amp @ 250w / channel. As my amp only has 5 channels and i wanted to give 7.1 a try I picked up a pair of AudioSource AmpOne/A @ 170w / channel.

I have tried hooking up the LFR's to both amps and to me is sounds identical. I did it more out of curiosity to see if one amp sounded better than another.

I have pondered if putting in a much larger amp would make a difference for me, and concluded that a better sounding room will be more bang for my buck. So I am in the process of building better sound for my media room.

The LFR's are one hell of a speaker and to be quite honest, I have pushed them louder than I would find pleasant listening to with no decernable distortion and my MCA5 wasn't clipping, I don't know what I would get if I upped to 500w / channel or more.
Posted by: 7800

Re: LFR1100 amplifier suggestions - 05/26/15 10:07 AM

I myself will be building a new home with a dedicated 13x18 room. It makes sense to hear and treat that room before making any equipment changes. I should also find out how much power the rear channels can handle. I assume it has to be less than the front. Thanks
Posted by: J. B.

Re: LFR1100 amplifier suggestions - 05/26/15 10:19 AM

it all depends on what you listen to and at what level.
the most difficult tracks to play usually are some movies played at Ref. Level:

Super 8: 122 dB max - (446 W/ch. front L-R) / total Watts for my 6.1 setup is 1275 Watts.
WOTW: 122 dB max
300: 119 dB max
LOTR: 120 dB max
The Pacific: 119 dB max (L + R front only: 460 W/ch.)

if you can play those at Ref. Level, without clipping or distortion, then you have enough power to reproduce any music or movie. lots of music plays at 115 dB SPL or a bit less, when played at "live level".
if you usually set your volume at -10 dB or so, then you need much less power: 10 times less.

you also need a bit more Watts than your calculations indicate, just to be sure your amps will never clip.

check the link below my signature for more on my setup.

Hope it helps.
Posted by: AAAA

Re: LFR1100 amplifier suggestions - 05/26/15 06:16 PM

The speaker cockpit!! I still cant imagine leaving that room without a nosebleed. But seriously, anything worth doing is worth over doing! Awesome!
Posted by: 7800

Re: LFR1100 amplifier suggestions - 05/26/15 06:24 PM

Thanks J. B. for the advice and link to your system. My system:
Arcam BDP300 dvd/cd
Arcam P777 amp
Marantz AV7701 processor
Monster 5100mkII power cond
Panamax 5100 power cond
SVS SB13ultra sub
Audioquest, MIT and Kimber cables
Axiom speaker wire
I think my issue is headroom. Got the front end crossed over at 40hz so nothing is working harder than it has to. I guess I'll finally go buy that SPL meter...
Posted by: 7800

Re: LFR1100 amplifier suggestions - 05/26/15 06:34 PM

"you're gonna hear electric music, solid walls of sound"
Posted by: MatManhasgone

Re: LFR1100 amplifier suggestions - 05/26/15 07:05 PM

My room is larger than yours @ 16.5'x17'x 8' ceilings. Effectively your amp has 20w more than mine by Arcam's specs. I had never gotten my receiver up above -10 db before it simply just started to sound excessively loud. Once I did go up to -5 db and the walls were shaking.

You have to also remember that with your amp that you have, the limitation is the power supply. You have 7 channels, but if you are just running your LFR's then you are really using 2(+2) channels. The rear 2 channels are only driving mid's and tweeters that really don't take much power. It's the larger woofers on the front that suck up the wattage. So think of it as using 2.5 channels out of your 7, you are probably getting closer to 300w out of the amp with quite a bit of headroom left over.
Posted by: 7800

Re: LFR1100 amplifier suggestions - 05/26/15 07:43 PM

I thought about the 4 out of 7 channel aspect. My amp has separate 1.5 kva transformers for the left and right channels with the center channel drawing from both. So I believe you are right when you say it's more like 300w 4 channels driven, and that's full range real watts, not "marketing" watts. The current is there. Bryston envy? Maybe
Posted by: dakkon

Re: LFR1100 amplifier suggestions - 05/26/15 11:27 PM

I'm powering my LFR's with a Krell 300cx for the front drivers and a KVA 250a for the rear drivers. For what it's worth..
Posted by: J. B.

Re: LFR1100 amplifier suggestions - 05/27/15 09:18 AM

7800 !
if you're worried about headroom, try changing the X-over frequency to 60 or 80 Hz.
giving that extra work to the sub will alleviate the demands on your Arcam amp and will have the same effect as buying a more powerful amp.
Posted by: 7800

Re: LFR1100 amplifier suggestions - 05/27/15 08:17 PM

Thanks J. B. I'll do more experimenting with the crossover settings.