[wkatzir]

Hello All-

     I have an interesting question to which I would appreciate any thoughts. I have listened to the Linn Katan's in their "aktiv" mode (which is essentially having them actively bi amplified) and they sounded much, much better then when they were conventionally powered. I am wondering, would the P3es2's benefit from a similar power situation? So, for the sake of argument, which would sound better, powering them using setup A or B? ***Room Size is 13' x 12.5' x 9'h***

A) QTY 1, Parasound Halo JC2, Preamplifier
    QTY 2, Parasound Halo A23, 125watt x 2ch Amplifiers
    QTY 1, Bryston 10B Crossover, Set to match the crossover points of the P3es2's

<or>

B) QTY 1, Parasound Halo JC2, Preamplifier
    QTY 1, Parasound Halo A21, 250watt x 2ch Amplifier

     I was also wondering what the crossover point on the P3es2 is? Any thoughts on these possible setups, or if you have any other recommended setups (without utilizing a tube amp), I would love to hear them.

Thanks-

Wes

[Occam]

Wes,

Those are lovely speakers you have there. Given their very low sensitivity and their definite preference for strong solid state amplification, I would hazard to guess that the internal crossover is rather complicated, and does substantially more than simply divide the frequencies. There might well be frequency contouring, notch filters, etc.... that is not straightforward in an analog line level crossover. That internal crossover is largely responsible for it wonderful soundstaging and imaging, and I personally would be recalcitrant to endanger those qualities with a electronic crossover.
Personally, I would consider leaving the Harbeths as they are, and adding a good subwoofer to make it an excellent full range speaker system.

FWIW,
Paul

[wkatzir]

Paul-

     Thanks for your thoughts.  I guess my mode of thinking was that by utilizing a crossover between the preamp and amplifier, and by having it set at the crossover point, it would make the amplifiers more efficient for the speakers by only having to reproduce  half of the frequencies.  Do you have any thoughts as to a preamp and amp setup that would mate well with the Harbeths?
     In regards to a subwoofer, I have a servo controlled, Martin Logan Grotto i that I used with my Magnepan's and I love it. I was thinking of incorporating it if need be.

Thanks again-

Wes

[Occam]

Wes,

The HL-p3 responds well to stout solid state amplification. I last heard the HL-P3es driven by a Bel 1001 MK IV, and it was a lovely match. Other amps that would do very well would be the Aspen Soraya (I use one) and a Platinum version of Steve McCormacks amps like the DNA .5 or 1. Given the outstanding imaging and soundstaging capabilities of your speakers, it really deserves this quality of amplification. These are $4-$5k amplifiers and you don't state your price range, but both the Bel and McCormacks are often available used, at substantial discounts over their orignial prices. No doubt there are other fine amps that would work synergistically, but I'm just mentioning ones I've personal experiece with.
As to preamps, thats a personal preference. A Convergent CAT SL-1 would work a charm. I roll tubes in mine to adjust for my personal preferences. The Modwright is another excellent tube hybrid preamp. A Klyne 7x (that what fed the Bel that fed the HL-P3es) is a great sandstate pre, as is the Plinus M8. Again, there are, no doubt, many excellent preamps out there. Again, I'm just mentioning preamps I've presonally used and loved. The preamps I mentioned are quite dear, but they do show up used.

As you didn't mention your price range, I've mentioned components of IMO 'equivalent' calibre. I think rather highly of your Harbeths....

FWIW,
Paul

[Stu Pitt]

The Harbeths are excellent speakers, and really deserve excellent amplification (and pre-amplification and sources) to really shine.

I've never heard a system that didn't sound miles better with an active XO.  I don't think there's enough of them on the market.

But, why mess with an excellent speaker?  I'm sure Harbeth really spent some time and energy in designing the XO.  Not to mention that if you don't like the results, you're probably going to be stuck with the speakers, or take a huge loss on them if you sell them and people know you removed the XO at one point.

Its a definitely a gamble.  At the end of the day, its your money and ears.  Does your Harbeth dealer have any insight on using an active XO with them?  The Bryston 10b is a top notch XO.

[wkatzir]

Hello-

Thanks for the replies.  I find the midrange on the P3's to be fantastic, the bass more then capable, but the treble lacks a bit of the attack I am looking for.  I am looking for preamp/amp setup that would help fix that.  Since the Linn setup had one of the best top ends that I have heard, I figured that a configuring the Harbeths in a similar fashion would give me the best of both worlds.  Which is why I posted the notion in the first place, to help vet out my idea. 

In terms of a budget I would say $9K Retail, meaning $4 - 5K via audiogon, would be the max for both units.  I have an Audio Research SP16 that I can either utilize or sell easily as it is mint.  I am leaning toward using it with an Ayre V-5xe or getting a McIntosh C220 and MC252 setup.  But, I am open to anything from a reputable company

-Wes

[Russell Dawkins]

The HL3 is based on the LS3-5A which was designed by the BBC for use as a near field monitor in remote trucks and similar situations. As such it has a cunning rise designed into the upper bass which compensates brilliantly for the lack of real extension. This characteristic also foils attempts to mate with sub woofers, in my long experience with mine. I bought a pair in 1994, intending to supplement the low end with a pair of Hsu subwoofers. I never managed to come close to a good match, and I attribute that to the bass lift engineered in at around 140Hz.
I wouldn't dream of touching the crossover or thinking there is any likelihood of duplicating its effect with an active crossover, even though the speaker would undoubtedly sound much better with this setup if Allan Shaw did it, but this is seriously inappropriate on such a small speaker which has such serious fundamental limitations to do with dynamics and bass extension. With Harbeths you are paying big time for such refinements as a very carefully designed crossover and to think you can substitute it with some generic device is really beyond optimistic.

The HLP-3's basic "problem" is that at 82dB/W it needs a lot of power to wake up, and yet it can't handle much power. Bottom line is it has very strict loudness limitations or a very small dynamic range.

Within that range, though, there is magic to be had, but not as much magic as the other Harbeths with the Radial drivers.
I would not try to compensate for the rolled-off sounding highs (which is more lack of distortion than anything else) with bright amplifiers - just accept it as a characteristic of the speaker and live with it until you can take the money you saved by not buying the Bryston crossover and put it towards one of the bigger Harbeths - unless part of your enjoyment is the constant changing of equipment.

One thing I would consider from the options you originally presented is the use of two A 23 amplifiers in a vertical bi-amping arrangement. This way the entire power supply of each amp is available for the bass/mid driver and the other channel will have a very easy time supplying 3.7kHz and up. I presume you would have vertically bi-amped if you had used the Bryston crossover anyway, since the 4" driver does cover about the entire range requiring any power - there isn't much power needed over 3.7 kHz.

[wkatzir]

Russell-

     Maybe I was not clear in explaining my thought.  I was never going to open or touch the speaker's crossover.  I was only going to use the external crossover to split the signal between the 2 stereo amplifiers thinking that the extra efficiency would improve dynamics.
     The HL-P3es2 is am my only option when it comes to Harbeth's due to the fact that they are to be used on a desktop and anything bigger will not work.  I know that later in the year the new P3's will be out with the radial driver, and maybe if I feel it is worth it, an upgrade will be in order. 
     If you don't mind me asking, what are you using with your Harbeth's?  Do you feel like 2 smaller amps would work better then 1 larger one given they are of the same make and series?

Thanks for the response-

Wes

[Russell Dawkins]

I didn't think you were talking about touching the crossover so much as trying to replicate its action with the Bryston active crossover. Dynamics would be improved only if you were to power the drivers directly, bypassing the passive crossover. If you were to "split the signal" with the external crossover, this implies using a high pass to the tweeter input and a low pass to the lo/mid input, with a slope of, presumably, your choice. This most definitely would interfere with the intended design characteristics of the Harbeth crossover since, at the least, the slopes of the passbands would be steepened.

If I understand you correctly - that you intended to split the signal and then go through the Harbeth crossover - then virtually as much benefit could be gained from a vertical bi-amping scenario with the amps you originally suggested (125 WPC) verging on overkill for this application (which is always nice) and probably serving your next upgrade to the larger and more sensitive Harbeth, once you get thoroughly hooked on the Harbeth sound.

I would definitely recommend two 125wpc amps over one 250wpc amp. You get more separation - not only between channels but between drivers - the option of very short speaker cables and the benefit of the fact that all things being equal, smaller amps tend to sound better than bigger ones.

I used to use a Sugden Au31, then two Au31s, vertically bi-amped, then Musical Fidelity A3CR on my Harbeths. Now I don't use the Harbeths at all, they have been boxed and ready to sell for 3 years and I've hardly used them for the last 14 years, since I got my replacement studio monitors. My original idea was to make the HLP3s, in conjunction with the Hsu 10" sonotube subwoofers my main monitors, used at about 4' listening distance. As I said earlier, I never could achieve a satisfactory blend between the HLP3s and the subs. When I got my Tannoy Ardens (15" coaxials from 1977 in big ported boxes) I found that
1] I was immediately able to mesh with the subs at around 40Hz
2] I was getting the best quality bass I had ever had, and one of the best I (or any of my clients) had ever heard. As an aside, I now know that while really pleasant and fun it was not all that accurate and thus my mixes would not "translate" well in the bass region to other systems.
3] The Tannoys were so dynamic by comparison that although the highs were ragged and crude by Harbeth standards, the overall effect was so much more relaxing that I basically couldn't stand to listen to the Harbeths, and so didn't. By contrast, the Harbeths sounded constrained, to put it politely - constipated, to not. They basically just sat there on their little stands in the nearfield for about 10 years before I decided that they had outstayed their welcome and I packed them up.

[wkatzir]

Russell-

     Given the fact the speaker must be small, can you think of something better for the job?

-Wes

[Russell Dawkins]

For an exclusively desk top system, to be listened to only at the computer, I would consider this Qinpu ensemble:
http://www.6moons.com/audioreviews/qinpu2/system.html

For desktop only, I would even consider these, considering the reviews by Gayle Sanders and the like:
http://www.soundmatters.com/foxl/index.html

I simply would not spend what you were thinking of spending if you were buying new, which is about $1800 for the speakers and $900 each for the A23 amps when $900 more would buy me a pair of K+H 0300s.
These are nearfield monitors, intended to be listened to as close as 1 meter, with a frontal size almost identical to the screen on my 17" powerbook (10" high by 15" wide) that inhabit an utterly different and unimaginably superior sonic universe to the HLP3, and for essentially the same outlay. There is literally no fair comparison - and the difference is 25% in cost. And they would fill your 13x12x9 room, too, which the HLP3s would not. They are a little shorter than the HLP3 and just over twice the width and weight. A stand could be conceived like a little table where the area under them on the desk could be utilized.
http://tinyurl.com/5s8j3k  click on "Technical Data", etc.
I have learned there is real value in midrange headroom, whether it is achieved by efficient 2 ways or, as in this case, by a 3" dome driven by suitable power.

[mfsoa]

I stumbled across this, from the Harbeth website forum:

regret that you have made a fatal assumption. I have already time aligned the woofer and tweeter in the crososver on the listening axis. If you tip the speakers backwards you will in fact un-align them.

The not-so humble "crossover" has several functions in a quality speaker:

1. Adjust the relative levels of the woofer and tweeter (tweeters are usually more sensitive and need to be turned down to match the woofer).

2. Adjust for the 'baffle step'.

3. Filter action at the top end of the woofer/mid and bottom end of the tweeter.

4. Shelving, or other frequency selective control or compensation.

5. Control of dispersion of sound on and off axis.

6. Time alignment. Note: With conventional woofers and tweeters that are spaced apart on the baffle (in contract to coaxial type drivers) it is only possible to optimise the time alignment at one point in space - logically on the listening axis (or indeed anywhere else you want, but only at one point in space).

and it has to perform all of these tasks simultaneously, without degrading the sound quality and most especially, without making the speaker difficult to drive. It is a complex multi-dimensional problem which appeals to me intellectually and I take considerable personal pride in doing the job properly.
__________________
Alan A. Shaw
Designer, owner
Harbeth Audio UK

[wkatzir]

Mfsoa-

     Thanks for that quote, as I stated above, I was never intending to alter the built in crossover.  I know that much time was spent on fine tuning it to the characteristics of the box and drivers and wouldn't dare to tread on that territory.

Russell-

     Thank you as well for the response.  A few things maybe you should know about the specifics for this system.  Firstly, I spend my work hours at my desk, and I have just sold off my main 2 channel system to switch to something smaller that would fit in my office as it would be used much more often.  The situation only allows for a desktop setup. I am willing to spend for something that will get me close to what I had and loved (Audio Research VS110, SP16, Magnepan MMG's, and a Martin Logan Grotto i).  Secondly, given that the system will be on anywhere from 8 - 14 hours a day, tube amplification is simply not an option.  Thirdly, if in the next few years I move or change things around, I would like to have a system that pull double duty as a standard hifi setup.  I know that I am asking the impossible, but there are some systems that would be better suited for that purpose and I am leaning that direction. 
     In regards to the K H monitor suggestion, I am intrigued and will do some research.  The price difference is a little more dramatic then you thought, Harbeth reduced the price on the P3's to 1495 - 1595 depending on the finish, but still not a jump that would put it out of reach.

-Wes

[Russell Dawkins]

K+Hs are a little hard to find at the moment. This may change as they were recently bought by Sennheiser. they are designed in Germany and made in Ireland (the 0300) and Germany (the 0410). The place to look would be pro studio supply channels - common musicians' supply places would be able to source them, but typically would not stock them except perhaps in the biggest cities.
Here's a 2004 review of the digital input model 0300D  which is more expensive:
http://www.soundonsound.com/sos/Oct04/articles/kh300d.htm