Legacy Audio Focus HD and amplification

HerculePirate · « **on:** 30 Oct 2007, 07:47 am »

Hey,
Has anyone heard the Legacy Audio Focus HD. What are the differences against the Focus 20/20.
What is the minimum Room Size for such a speaker.
Also the amplification is in question. The speaker does require a high current amplifier.
I mainly listen to Rock, Pop, jazz and electronic bands like Radiohead/Portishead/Massive Attack.
Someone did suggest the NuForce Ref 9 V2. He is using them with the Wilson Watt Puppy 6 and he too listens to similar music. He quoted damping factor and I am not sure of the bass delivery of that amp for that matter even the Icepower modules. Can anyone shed some light if these amps (Nuforce/Icepower) will give the profound, wholesome, tight and muscular bass that I am looking for...that totally control the woofer...(they do claim so...)
Any other suggestions for amplifications are welcome.
Thanks
Hercule

Imperial · « **Reply #1 on:** 30 Oct 2007, 01:12 pm »

Well, I actually think it is a good thing to know that the input impedence of most such digital amps
are rather low.
Hence they demand somewhat much of the partnering preamp, that is the preamp must be able to output
more current than "normal" ...
What happens when this isn't the case, is that bass quality suffers...
So this; Hercule, should be on you mind when choosing an amp!

And this is my take on amplification.
I don't have much experience with either digital amps or the speaker in mention, so others can help you there..

Imperial

stereocilia · « **Reply #2 on:** 30 Oct 2007, 01:44 pm »

I haven't heard the HD (I'd like to), but I own the 20/20. I get great sound with my Audio by Van Alstine Fet Valve Ultra 350; and I play some hard-hitting music at moderately high volume sometimes. I haven't heard anything yet that sounds like I'm over-driving the amp. I haven't used too many amps, (I'm not much of a gear flipper these days) but in general I liked the sound of amps with a reputation for low-impedance drive capability. Or maybe, it has more to do with MOSFET sound. Personally, I think a room that allows you to be at least 8 feet away from the speakers with a little breathing room is minimum, but you could ask Legacy.

Toka · « **Reply #3 on:** 30 Oct 2007, 03:08 pm »

Can't offer any input on the Legacy speakers, but the NuForce amps do not use ICE modules...they have their own design. They should be able to drive those speakers, as will the AVA amp mentioned. There are several options, all good.

bummrush · « **Reply #4 on:** 30 Oct 2007, 03:54 pm »

I used ice amps with my Legacy Studio speakers,not a good combo,i liked it at first,and it wasnt one of those things that you instantly notice,but the sound was mid fi at best,using a counterpoint solid 1e amp and a coda pre amp couldnt be happier

stereocilia · « **Reply #5 on:** 30 Oct 2007, 04:53 pm »

I forgot to add that if the HD is as sensitive as the 20/20, then be careful not to get a noisy amp. I once had ground loop trouble (not with my current amp) and it was very audible from anywhere in the room. When I hooked up less sensitive speakers the problem was only audible an inch or two away. I've never tried anything but class A or A/B amps; so, I will not comment on ICE, NuForce, etc.

*Scotty* · « **Reply #6 on:** 30 Oct 2007, 06:33 pm »

There is no good reason a speaker with 96dB sensitivity should require a high current amplifier unless the impedance curve dips substantially below 4ohms at some point. The manufacturer should be able to supply an impedance curve on the speaker. This sort of measurement is routinely done as part of the design process and should be readily available. As this speaker has all new drivers compared to the old 2020 and there is no reason to assume that it has anything like the same power amp requirements. As far as space requirements are concerned, this is a large speaker and it unlikely that it will produce a coherent wave front at a listening position closer than 9ft. to 10 ft. I also wouldn't expect them to work well in a room smaller than 12ft.x15ft. and bigger would be better. Most of the answers to your questions should be available from Legacy Audio.
Scotty

stereocilia · « **Reply #7 on:** 31 Oct 2007, 04:52 pm »

Scotty,

If you've heard both of these speakers, I would be interested in your comments about the differences in sound between them.

True: other than having the same dimensions, the same price, the same number of drivers arranged in the same way presumably by the same designer, a similar name, the same nominal impedance and sensitivity, the two could be apples and oranges.

BTW as for the 20/20, it does prefer a bigger room, but not everybody would rule it out for a medium one. Also, the Stereophile review of the 20/20 shows that it is a difficult load. But again, this means nothing for the HD. I don't know if anybody other than Legacy has measured it.

*Scotty* · « **Reply #8 on:** 1 Nov 2007, 04:16 am »

stereocilia, Unfortunately I have not been able to hear them side by side,my reply was based on applying a little logic to HerculePirate's question and a comparison of the Legacy HD published specs from the Legacy website and the Measurements from the Stereophile review of the 2020. My room recommendations are based on my experience with a similarly sized loudspeaker with similar low frequency extension and efficiency.
See links below -
http://www.sixmoons.com/audioreviews/roadtour10/roadtour10.html
http://www.reimerspeakers.com/tetons_gs.htm
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1233
Hopefully this redesign of the 2020 has resulted in more benign impedance characteristics. There is no reason that a speaker with this sensitivity can't be driven by a SET once the dips to 2 and 3ohms in the curve are eliminated. If this has been done a good loudspeaker design would work with a wider range of equipment and a appeal to larger audience.
Scotty

stereocilia · « **Reply #9 on:** 1 Nov 2007, 02:10 pm »

agree, more amp choices is always a bonus. A friend of mine has an Oris Horn/SET rig; there does seem to be some ineffable thing that SETs get right. At one time I did consider ordering some Speltz ZeroBoxes and trying some weaker tube amps, but I got over it. BTW Those Reimer speakers seem really remarkable...nice.

I wonder if anybody in auido-land wants to take on hosting one of those 16 speaker shootouts with speakers in the 200 lb. category? (Hey you! with the fork lift...I'm looking in your direction

) Anyway, I imagine somebody somewhere will publish a Focus HD review.

HerculePirate · « **Reply #10 on:** 2 Nov 2007, 03:14 am »

Awesome looking speaker......wow...beautiful...
too bad they are only in the US...dont have any dealers outside the US World.
ha
I am thinking of the Odyssey Stratos Mono's or Extreme's...since they have high current capability.
I had a friend who suggested NuForce Ref 9 V2 SE...any views...
Another guy on the Legacy Audio site is using the Hafler 9505 power amp
Thank
Hercule

Imperial · « **Reply #11 on:** 3 Nov 2007, 10:21 pm »

Well... (Read the following only if you want to know a bit about what dampening factor really is!)

Dampening factor, current and bass quality.
There is a link there, but it is not totally connected!

Amps such as YBA (factor ca 300) and Plinius (even lower) also have a superb bass quality.
The YBA does this with it's very fast current discharge from the outputstage. (480 amps, that's as much as an arc welder...

)
-
The Plinius uses asymetrical drive, so it pushes with more current than it pulls (On the voice coil) - Simplified..
-
Then you have some tube amps with amazing bass quality ... lots of ways to do this in the tube world.
-

If you have a dampening factor of say 500, that does not mean that the voice coil see this amount of grip!
This is more like... : http://www.trueaudio.com/post_013.htm

So don't look blindly at the specs, that alone does not give you what you think is the best.

It's like this really:
The higher the dampening factor, the less the speaker can influence the amps output stage, but and this is rather cool , the amp can be actually less powerfull and still not be affected.
If the amp has a lower dampening factor the output stage has to be that much more powerfull to remain unfazed by the speaker load.

So lower dampening factor does not mean that the amp is weaker, it means that the amp has to have more power to still controle the woofer coil.

So is upping the dampening factor a way of compensating for the outputstage's weakness?
Well, this can mean that the input impedence of the amp has to be lower, and that in turn can stress the preamps outputstage, and in return, affect the bass quality, or rather, the frequency response can actually fall downwards a bit from say 100hz and downwards if the outputstage really has to drive a to low inputspec on the amp.
Okay this was a more tech stuff than this here thread calls for, but I thought it a nice read if one wants to know a bit more..

Of course you can have a amp with massive dampening factor and that amp has a massive outputstage in addition!
Then we are talking grip!

Imperial

HerculePirate · « **Reply #12 on:** 4 Nov 2007, 08:12 pm »

What amp whould that be...????
ANY NAMES??
Hercule

HerculePirate · « **Reply #13 on:** 6 Nov 2007, 09:19 pm »

i have a few suggestions on the amplifications:
1. Nuforce Ref 9 V2 SE
2. Odyssey Stratos Mono or Mono Extremes
3. Van Alstine Fet Valve Ultra 550
4. Belles 350A Reference amplifier
5. Pass Labs (....second hand Obviously)

any suggestions are welcome
thanks
Hercule Pirate

richidoo · « **Reply #14 on:** 6 Nov 2007, 11:16 pm »

I have 2020, but not heard HD yet. I have a very large room, 39 x ~20, 7500+ cu ft. that suits them well. Spaced from front wall is important to reduce SBIR. The new HD has no rear drivers, I think the 3rd woofer on the back made integrating the speaker to the room difficult. But it also must reduce ultimate bass response, which for most people will still be more than enough. But Focus was the only speaker on the market below $10k that had low distortion response flat all the way down to 20Hz. I hope HD can still do that, it is truly awesome to hear organ music and synth bass that low. The speaker is very revealing of any amp, so it is wise to audition them at home after you get the speakers.

I tried Nuforce on it way back. Great tight bass, but not enough current for the Focus (160watts at the time) when really pushed HARD! Normal extremely loud music was fine though. I too hope the impedance dips are resolved. Removing a big woofer in series is one way to improve the dips. The mid and highs of the Nuforce 9SE were not great, but probably improved some since then. They sounded the same at RMAF 2006, whatever they had there.

Mac MC-402 was another good combination with the Focus 2020. I would recommend that. But might be a bit too polite if you want to melt hair. Worth a try, great value for what you get. Built in autoformer gives low output impedance. Built in power conditioner too.

I have Manley Snapper tube amps. Not as much bass power or grip as SS amps, but for me the added tonal accuracy and aliveness was more than worth the trade off. They still rock great and shake the house with organ music or bass synth.

I currently use Altmann BYOB amp. Great slam and bass control. Best tone and lifelike presence of any amp I have ever heard. But they are only 15watts, so they will clip into very big load like Focus playing orchestra very loudly. Ohwell. If HD is more benign load with same sensitivity, it would be a great amp for it, especially biamping one pair per side.

Battery PS has no current restriction, so no bass problems despite low ultimate power. 2020 is 95dB per 2w, 104 per 16W. Not for everyone, but I like it.

Good luck