[TheChairGuy]

[http://www.audiocircle.com/image.php?id=1149]

Hope I'm not using up bandwidth, here goes another try....[/img]

[nathanm]

[/list]

Code: [Select]

[img]http://www.audiocircle.com/image.php?id=1149[/img]

It's magical, aina?

[TheChairGuy]

Nathan,

Cool, thanks.  I literally woke up at 4:55AM with a start....I realized what I probably was doin' wrong, and you confirmed it.

Like a new kid with a bike and training wheels, I think I'm gonna' go down to 'testing' area and try it out.  Thx. again.

[nathanm]

Active speakers sure, but this guy's got active amps too!  I mean, they're on a weightlifting regiment already!  Very nice!  I'm glad to see the Norh monoblocks are pursuing a healthy lifetstyle.

Ahh, so that's what they call a "sand amp"!

[TheChairGuy]

Active speakers sure, but this guy's got active amps too! I mean, they're on a weightlifting regiment already! Very nice! I'm glad to see the Norh monoblocks are pursuing a healthy lifetstyle.

Ahh, so that's what they call a "sand amp"!

You crack me up, Nathan!  Actually, the sand bags are a temporary fixture on top of the amps - they'll be placed at the bottom of the speaker cabinet (inside) this weekend.  That should remove any last cabinet resonances from my listening pleasure.

Did you miss the 10lb barbells on top of the speakers, too?

Of course, not all sand sounds the same.  This is special, handformed 'cryo' sand with perfect grain silicon structure that helps refract signal-eroding gamma rays back into the lower stratosphere - I can't reveal the price as I got a special deal from the seller.  

[Andrikos]

Hey chairguy, are those nOrh Le Amp II's you got there?????????????????

Where are mine?!?!?!?!?!
I ordered 3 of them a couple of millenia back.
How do those babies sound? Tell us pray tell!

[TheChairGuy]

Andrikos,

No, they are Mr. Barnes' previous creations, The MultiAmps.  I've seen the pics in Norh's website of the Le Amp II's and, for sure, he has designed the Le Amp II's with a family look.  

They look to be almost identically sized...albeit with prominent cooling fins on the sides of the Le Amp II's.

So, I can't help you with the sound.  The MultiAmps are okay - with active crossovers engaged.

[Andrikos]

Phew! You scared me for a while... I thought you stole my amps!

[John Casler]

Did you miss the 10lb barbells on top of the speakers, too?

Don't feel bad I have over 200# sitting on top of my LARGER Sub.

The best are the rubbercoated barbell plates or dumbbells

Talk about mass loading, mechanical coupling, and vibration dampening

[TheChairGuy]

Don't feel bad I have over 200# sitting on top of my LARGER Sub.

The best are the rubbercoated barbell plates or dumbbells

I'd have put more on top of my speak's, but they have di-pole tweeters.  I'll decouple them with a few dabs of audiophile....Plast-i-Clay.

Does 200lbs keep those things from going airborne?

[Andrikos]

Chuck lives on indeed!!

[TheChairGuy]

I thought I'd pull this oldy, but goody post up from the pile and post a couple comments.

Unusually, I had a little time yesterday (Sunday).....my football team (NY Giants) utterly suck so I cared not to watch football.  Anyhow, time to re-arrange the stereo a bit.

I have a perfectly good pair of Vandersteen 1C's sitting in the closet since I went 'active' with my modded RatShack Optimus LX-8's.  I don't get out to listen to good systems (nor live music in good venues due to travel schedule) enough to re-index my ears.  The Vandy's have sat idly by for 6-8 months while I gradually improved the active speaker system.

These are well thought thru, well reviewed speakers lauded for their 'openness', 3 dimensionality and strong bass (for their $800.00 retail).  A lot of folks use them with much more expensive gear than their humble retail might suggest.

Side by side with the even more modest active LX-8's - no contest.  Except for bass extension (which definitely counts) and spl's, because the Vandy's are floorstanding and transmission line (one of the reasons I bought them - I have heard some great transmission lines b4), everything else was lacking.  The immediacy was gone, the 'right there' presence was no longer felt - it sounded less like music and more like chain store boom tactics.  That is not to slight Vandersteens, but they just pailed in camparo to the even more modest active system.  Adding to the calamity was the 'ringing' sound I get from all metal dome tweeters I have ever heard...the modified Vifa in the Vandy being one of many that have killed my ears.

The MultiAmps were used in stereo (one amp) and bridged (2 amps with 50% more power) on the Vandys, and all connections were treated with DeOxIt.  In stereo for a change, I used one MultiAmp to drive one of my newly acquired N.E.A.R. Boom-2 passive subs (passively crossed over at 80Hz), and although (for the first time) I had a 20-20 Khz window to listen to, I much preferred the smaller soundstage of the active LX-8's.  I don't beleive it was teh room being overwhelmed either - it was simply a big win for active.  

It seemed to me the MultiAmps were straining to reach potential in the passive system, and a good bit of their downsides (shallow bass, a bit grainy) were mitigated without a passive crossover in the way.  
You really don't need exotic and expensive amplification with an active system; the benefits of big mutha' expensive amps seem less important.

Bottom line for me is that you can create a more realistic music presentation for equal and even less cost with an active system (a 2 way, at least).

[DVV]

I thought I'd pull this oldy, but goody post up from the pile and post a couple comments.

Unusually, I had a little time yesterday (Sunday).....my football team (NY Giants) utterly suck so I cared not to watch football.  Anyhow, time to re-arrange the stereo a bit.

I have a perfectly good pair of Vandersteen 1C's sitting in the closet since I went 'active' with my modded RatShack Optimus LX-8's.  I don't get out to listen to good systems (nor live music in good venues due to travel schedule) enough t ...

Two way active is really good, but three way active is unbelievable if done properly. By "properly", I mean if the electronics have been done well (which should not be too much of a problem, as one can typically get away with single-ended push-pull (SEPP) power stages for mid and treble) and the selected drivers are of some quality.

In my view, the greatest single problem with 3x is selecting a good midrange driver. This is far harder than it may look at first glance, but remember it will cover the ear's most crticital and sensitive range, from say 800 Hz to say 3-4kHz, where 99% of the action is. Then again, this is a carry-over problem of any 3x speaker.

If used in a straight (i.e. no passive XO) mode, many good bass drivers will require less than 100W of power to operate well beyond what your wife, kids and neighbours (not necessarily in that order) will tolerate on a daily basis. Hence, no mammoth power amp is required. Also, since they are individually driven, you can freely mix and match 4 or 8 ohm drivers, since you can always optimize the power amp for (almost) any impedance.

The same is true of the mid and tweeter. Look in data sheets and you'll find most are limited to around 50W of power in a straight mode, in addition to the fact that they are usually pretty efficient and don't need much power. This opens up further opportunities, such as amps biased into pure class A far more than would be otherwise possible (since you can work off lower rail supplies), or even pure class A amiplification.

As for the cost, it will not be small, but it does not need to be astronomical either. Also, it is highly flexible - you can decide how much goes on what, and avoid the commercial approach of using $10 tweeters in $2K speakers, a VERY common failing. In other words, your investment can be made much more wisely.

Cheers,
DVV

[JLM]

http://www.pmcloudspeaker.com/aml1.html

Content includes Bryston amps/crossovers, some equalization, transmission line loading, and wave guide.

And they're only $5,200/pair!  Plus matching stands of course. OTOH the built-in 210 wpc of Bryston amps alone would cost roughly $3,000.  Its another active speaker with the tweeter dropping down to 1,400 Hz.

One review states, "It is also designed to play at very high levels with very low distortion, essentially a studio monitor built to audiophile specifications. "  What exactly does "studio monitor built to audiophile specifications" mean?

[TheChairGuy]

DVV,

I am learning quite a bit about the 'active' process with my cheap Optimus LX-8 speakers right now; my plan is to step up into something more extraordinary once I understand it better.  I still have a few enhancements I need to tinker with...ie., soldering my speaker cable direct to woofer basket tabs (eliminating the, allegedly, sound altering metal binding posts), applying constrained layer damping to the woofer cone (yes! The Marigo Magic Dot approach) and basket.  Also, I'm 'double-stacking' the woofer magnet to assess if it helps or harms low end response....the driver is rolled over at 2KHz to the tweeter right now, so it probably won't affect upper midrange response adversely.  It's all alot of tinkering....the fact that it is so cheap makes me not care particularly if I ruin it somewhere along the line.

My tweeter, the dipole Linaeum, is mounted topside of the cabinet (you can see in the pics), so they are already hard-wired from tweeter to amp -eliminating any binding posts.

Simply miked instrumentals and the such are spookily real right now, but once the music gets a little wild, the cheap 8" Peerless driver can't keep up (for a variety of reasons I'd guess).  A 3 way design, correctly implemented, could be impressive indeed.

Unfortunately, this is my slow period and in mid-January I get busy traveling again regularly...leaving a lot less time to play around.

JLM - I have heard some spectacular Transmission Lines over time; the PMC is highly regarded.  It's probably pretty wonderful and robust with hardy Bryston's pushing it without power robbing passive crossovers.

[DVV]

DVV,

I am learning quite a bit about the 'active' process with my cheap Optimus LX-8 speakers right now; my plan is to step up into something more extraordinary once I understand it better.  I still have a few enhancements I need to tinker with...ie., soldering my speaker cable direct to woofer basket tabs (eliminating the, allegedly, sound altering metal binding posts), applying constrained layer damping to the woofer cone (yes! The Marigo Magic Dot approach) and basket.  Also, I'm 'double-stacking' th ...

Nothing "alleged" about it, it's a well known phenomenon. I don't know how it's called in English, but it's a phenomenon of contacts between two different materials. There is ALWAYS an altering of the signal simply because two different materials have different electrical properties.

Actually, this is most of the reason why it's good to have as few contacts as possible, not to mention the fact that all contact points are pure !@#$% but soldering is the least !@#$% of them all.

Hence, you plan to solder directly is an excellent idea, no two ways about it. You may not be illuminated with the light of revelation, but you will have a cleaner signal, that's for sure. And at the level you are on and even more so on the one you plan to reach, the difference is naturally smaller (law of diminishing returns); notwithstanding that, I would do the same anyway, let a job be brought into its full context if you have started it. And ultimately, you have nothing to lose, only to gain.

Cheers,
DVV

[MarinRider]

1/
I sold my Linn active system because the bass was just plain wrong. OTOH the mids and treble were clearly superior in active mode versus passive. Linn use a lot a bass boost below 100Hz in their active systems - I defeated this on the active XO to provide a flat response and it sounded thin and weak. I suspect a moderate amount of bass boost would have been ideal. Before I sold this system I preferred it in passive even though it was  grainier and harsher, it was also more immediate sounding and the bass more tuneful.

2/
Some years back I heard a whole hierachy of Naim systems at a hifi show, the cheapest one was best. The £50K one with umpteen power amps was almost unlisteneably harsh. I would add though that modern Naim stuff sounds a lot better.

3/
The best system I have heard by some margin (B+W speakers @ £14K, can't remember the model, with Classe SACD and Ohmega power amps) was passive.

I have heard some good active systems but for DIY it's hard enough getting simple systems to sound consistently good without adding the extra complexity of an active system.

Dave

[WerTicus]

active systems are simpler than passive in my book...

you could passivly filter out feqencies on the inputs to each amp if you wanted to. too easy

[audiojerry]

I'm in agreement with MarinRider.
Active seems like a simple solution, but it apparently it is not. I have not heard that many active implementations, but none have sounded natural. They can sound powerful and effortless, but there was always something about the sound that was not quite right. The problem might have been the amplfication; it might have been the active crossover. Others, whose opinion I respect, also feel that active systems aren't there yet.

[DVV]

I'm in agreement with MarinRider.
Active seems like a simple solution, but it apparently it is not. I have not heard that many active implementations, but none have sounded natural. They can sound powerful and effortless, but there was always something about the sound that was not quite right. The problem might have been the amplfication; it might have been the active crossover. Others, whose opinion I respect, also feel that active systems aren't there yet.

I beg to disagree, Jerry, in my book, active systems have been there since the mid-70ies. Or, specifically, since two active systems hit the market - Philips' Motional Feedback series and UK's Red (if anyone even remembers them nowadays).

I agree completely with the view that active systems, like any and all other audio gear, will produce radically different sound from one extreme to the other. This stands to reason - different drivers, different crossovers, different amps, etc. Obviously, such will also be the range of we hear, from what we downright hate to what we love, with anything in between.

I believe one of the key strengths of the Philips system was in the fact that there was a number of adjustments you could, and in fact were expected, advised and coached to do, to each individual driver, and the speaker as a whole. This allowed for unparallelled fitting in of the speaker to virtually any and all rooms, in itself a masterful idea and job. Furthermore, those were the days when Philips dedicated some really wise people to such projects (incidentally, one of them was Professor Matti Otala, the Finnish amp guru, who took part in designing the amps, after which he went on to work for Harman/Kardon for 12 years). Later on, they got Marantz as part of the CD rights deal with Sony and relegated all audio onto Marantz - a damn fool mistake if you ask me, but that was that.

Anyway, those speakers could - and generally did - blow the mind of anyone who heard them well set up. And herein lies a problem - you really had to set them up for best results, which as you can imagine most people simply didn't bother to do. Those that did, and I met a couple of them, enjoyed a quality of sound you'd be hard pressed to find even today, almost 30 years down the road.

Red from UK was much the same - set it up properly, and it could work magic. ATC today can also do the same, work some powerful voodoo and teleport you from the room to the stage or the audience.

But there were others who truly missed the point. The much revered Klein&Hummel from Germany did, does and probably will continue to sound aggressive, and calling it harsh is being polite, it's incisive - but with your eardrums. Oh, they are capable of prodigious numbers of decibells, the trouble is that those decibells are all skewed, skewered and sometimes barbecued. Awful! I would never buy them.

Contrast these with offerings from Switzerland's Studer and stand in awe. Much smaller, but so precise, to pinpointed, yet not aggressive, not harsh, honestly trying to be neutral. But then, Willi Studer has been making stuff for audio pros for 50 years.

Jerry, the trouble with most commercially available active systems is that they try too hard to meet a price point, and to that end, they cut far too many corners. Typical failings include weedy power supplies, hybrid output stages (power ICs, often by Sanyo or Technics/Panasonic), s**t drivers, etc, etc, etc.

They reason like this - who, or how many, will be willing to buy a system with high quality amps and power supplies with real muscles, driving high quality drivers, when all that will end up costing well into four figure numbers for even a small two way box? And this is not altogether wrong - how many companies can you name straight off specializing, or at least having produced, some memorable active systems? In other words, such manufacturers are NOT in the focal point of the general market, where production and sales numbers are, and hence where big profits lie.

Lastly, a subjective problem - audiophiles can't tweak them half as much as they can when playing the game of mix'n'match.

Ah, my sssssinusssesssss!

Cheers,
DVV