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OK, so keep my Avatar in mind when your read this. I have a separate amp for my bass bin, getting the receivers pre-outs because I need about an extra 5 db of gain in the FH-1 with K33's vs. the top section driven by my AV receiver amp (K402/K1133 with QSC/DE-250).Also need a certain amount more gain in my Tapped Horn sub with the amazing LAB 12 woofer. Because my receiver sets up the relative gains against an 85 db industry standards when it measure at my sweet spot, all this is taken into account by setting the levels there
Because the average and dynamic levels of CD's, DVD's and Blue Rays are all over the place, the only to maintain a stable level (so I don't piss off my neighbors) is to use a db meter before a music or movie session.
My system setup auto detects my source in the Panasonic Blue Ray player and sets up for 2.1 or 5.1 by itself. The majority of my time is spent listening to 2.1, hence the post here. The typical setting on my somewhat obsolete Onkyo AVR typically ranges from -20 db to -30 db setting on the level control (Right and Left channel are set to -12 db internally after Audyssey calibration, for a total of -32 to -42 db nominal against the receiver's supposedly full output, not including whatever "headroom" they put in there). Setting up some Jazz music at about 77-85 Decibels average at my sweet spot on the couch, (slow C curve on my Radio Shack DB meter).
I whipped out my digital voltmeter and measured at the speaker terminals of each section on the Right channel, plus the sub. I knew I was using very little power before I began, but now I can put real numbers to it. I had a Jazz CD with heavy electric bass content, so I set the average level to 3 tracks total to my usual level of satisfaction, which is usually -23 db setting on my receiver (Right and Left channel are set to -12 db internally after Audyssey calibration, for a total of -35 db nominal).
I went to the track that is the loudest on there with the most bass and did my measuring. I'm not sure about the response time of the meter, but I looked for the highest voltage value detected and rounded up. At the Xover terminals (feeding the two top horns' capacitors, I got 1.5 volts on the sub's LAB12 terminals, 0.36 volts on the FH-1, and 0.28 volts on the treble section. The are the highest readings and most of the time they were less than this
So the mono sub's, which has it's own amp fed from the "sub out" on my receiver, and set to -6 db internally by Audyssey, according to ohm's law ( Voltage squared over average impedance of 6 ohms) yields 2.25/6 ohms=0.26 watts (about 1/4 watt of power).
Similarly, the 5.6 ohm K-33 needs 0.130/5.6ohms=0.023 watts (23 milliwatts), and the treble section is .078/8 ohms=0.010W (10 milliwatts).
Paul W Klipsch told me to add 17 db headroom, which he measured from his own live symphony recordings. If we double that amount, and round up to a plus 20 dB headroom, we need 100 times the power to achieve it. This means my receiver will most likely never put out more than 1 W on the highest peaks in my 15x18 foot room with 7 foot drop ceiling on the K1133/DE-250 compresson drivers (since it's 100W/channel, I still have another 20dB headroom on top of it, it can NEVER clip).
The K33 will see a peak of 2.3 watts, and the LAB 12 will see 26 watts peak from a 200 watt per channel amp, with only 1 channel used. Even if you add another 10 db (yet another 10X more power) that may be needed for the +10db in the LFE channel from movies (requiring 1,000 X more power than my measurements), it would mean a 260 Watt peak requirement.
You can see that in an all-horn system, the subwoofer channel potentially needs all the power and the rest can be driven by flea powered amplifiers.
How many guys that have Tuba HT's that do a 20 Hz sine wave test at 10 Volts are flexing their drywall and windows? Now you know why large format horns ALL have ridiculously low distortion and wide dynamics. The voice coils never heat up and behave in a high distortion, non-linear manner from thermal compression. Comments invited.
Claude
5.1/2.1 wall of sound Stacks: Front L&R=LaScala Type Bass (Peavey FH1 with K-33 woofers), Klipsch K-402/K1133 drivers, B&C DE250/QSC Horn Tweeters, Front& Center=Cornwall I, L&R Sides=KPT-200's, 18 foot long folded Tapped Horn "coffee table sub with LAB12 B&W amp, all Driven by an Onkyo 706 Receiver, Hats off to Tom Holman and Audyssey EQ!!
Edits: 05/09/12 05/09/12Follow Ups:
You should try a little single-ended tube amp on those horns, not some 100W receiver. BIG difference! Even a cheap one, I think you can still get those $250 things from Hong Kong.
I had tubes before....Stromberg-Carlson, Mac, Citation II, Marantz, etc. I would go with Nelson Pass First watt Class A stuff before I went back to Valves. Solid state amps, especially those well integrated on Silicon, are pretty hard to beat.Recently heard a 2A3 on2-way Klipsch Jubilees......tubby bass, but the treble was nice on the TAD/K402's. If I were to go the tube route, I would do what Saul Marantz himself told me about 35 years ago when I was just a kid with my first pair of Khorns...............Tubes on the mid-tweet, Solid State on the woofers.
Edits: 05/11/12
Right on! That has always been my advice, too. SS on bass, tubes on mids and up. I have also been steering away from tubes these days.
I'd not generalise the quality of SETs from a less than ideal match between amp and speaker. Even when well matched, a quality SET amp might not have the outright slam of some SS, but they would not sound "tubby" and would likely have other endearing qualities.
Cheers.
I do not deny the benefits of the "pleasant distortion" characteristics of valves when it comes to the predominance of 2nd order harmonics. They do sound good IN THE TREBLE SECTIONS that way
However generalized my comment might be deemed, it's a been there, done that, for me, too many years ago for with Saul Marantz himself. The lower source impedance of solid state is a better current source and takes better control of any woofer section, even horn loaded ones. so it's not a good move to drive a woofer section with tubes.
What I'm not fond of in the case of tubes is the high operational voltages required, the wear down the insulator components, and the transformers required at the output stages to step down that voltage, the constant replacement of tubes, the warmup period required just to listen to them, the waste of energy required to provide mere MILLIWATTS of power required for good midrange and tweeter, and the frequency response anomalies involved in the interaction between output transformers and passive crossovers feeding voice coils. No thank you. Been there, done that, got the T-shirt.
On the same note, with the advent of 96Khz sampling and 192 Khz. sampling with 24 bit depth, digital storage is clearly superior to analog in every way but the mainsteam now prefers crappy MP3's for fast download$. Even in the vinyl days, very few producers took full advantange of the medium and simply made good recordings without making drums kits sound 15 feet wide. Dave Brubeck's original 1963 "Take Five" is a good example of good recording.
I'm also not fond of hearing how good "vinyl" is where you drag a rock through a ditch at varying velocities at 20,000 lbs./square inch of pressure on oil well derived material that wears out more and more with each play. I remember how crappy the pressings were in the USA back in the 70's.
Now we have superlative SS amplifiers from exotic class A designs from Nelson Pass, all the way to light weight multi kilowatt amplifiers for PA with high resolution digital Xovers.
Seems silly to me to run power supplies of a few hundred volts on a power amp to end up with stepped down impedance mistmatches that make the output so "load sensitive." But hey, if people think SE tubes sound better, who's going to convince them otherwise. Probably the same people who spend $15,000 for copper cables where it was long ago proven than anything beyond 12 AWG stranded copper was stupidly ridiculous.
Well, I bought my speakers from a First Watt Distributor - liked them with the speakers but not nearly so much as with my SE 45 - yet somehow found a brain cell or two and hooked the speakers to the amp with a pair of Anticables I picked up for $25.00.
You would think someone who has been around as long as you say you have would understand that some having different taste from your own is a fairly normal state of affairs. Not a matter of right or wrong or smart or stupid.
Taste is one thing, that's music, amp, and transducer selection as well as room selection and modification. No issue with choice there.
However I will stand by my stupidity comment on $10 worth of copper being sold for $15,000.
Well said!
Had to do with the lack of paragraph spacing. Made your post extremely hard to read. I still have not read it.
Are you using an Apple Computer?
Cut-Throat
I always use paragraphs, but they dissapear on the Klipsch board. I edited here.
nt
Cut-Throat
I guess I am really tired and have only one eye open but I have absolutely no idea what this thread is about. I did want to know what the big mid horn was. "tubes make nice distortion" omg do people still believe that's what tube amps are about?
This is the idea behind Nelson Pass' First Watt amps. The first watt is the most important, since that is where most of us spend our time.
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