Deang

How much does it cost to be "your friend"?

Ah yes, isn't the internet great? Good article below by Thomas Dunker. Why Horns?? So why would anyone want to use horn speakers today, when we can have 100W amps at low costs? As I hinted in the previous paragraph, horns DO have other special qualities than just high efficiency. Okay, it's necessary to understand a few basic things about HOW HORNS WORK in order to say WHY they do some things better than other speakers. (You'd be amazed at how many people who simply refuse to believe that horns can be used for serious music listening because somebody told them so or because they think horns all sound like megaphones.) A horn can be viewed as an acoustic impedance transformer. Turning mechanical motion (a vibrating diaphragm) into sound waves in air is in many ways a difficult thing to do. The most fundamental problem, which has a lot to do with the issue of efficiency, is that the difference in DENSITY between a paper or metal diaphragm and AIR is huge. There is a tremendous impedance mismatch. This fact explains that sound travels very far through denser media like metal, water or rock. In a speaker-air situation, the speaker diaphragm can be seen as a high impedance source (solid material) and the air being a low impedance medium (the air does not easily load down solid moving objects). There is a reason why humans can't fly by waving their arms! What the horn does is to help the transducer couple its radiated energy into sound waves in air by means of an impedance transformation. What this means is that it creates a higher acoustic impedance for the transducer to work into, which means that more power is transfered. (Analogous to putting an antenna on a radio transmitter, which seems like an obvious thing to do!) Basically, a horn is a tube or conduit with increasing cross-section along its axis. The narrow end (where the driver sits) is called the horn throat, and the large end (which opens into the room) is called the horn mouth. Sound pressure is defined as pressure change per unit area. In a horn, the wave front is restricted by the inner walls of the horn, and the area across the horn increases as the wave front approaches the horn mouth. So what happens here is that at the throat we have a small area and high pressure with small amplitudes, efficiently loading the diaphragm. As the wave fronts travel towards the horn mouth, the pressure drops, while the amplitude and the area increases. A horn also has the property of directing the sound into a narrower beam, which increases the on-axis sensitivity (SPL/1W/1m). Increased directivity combined with high electric-acoustic conversion efficiency means that horn speakers are very easy to power, even with very small amplifiers. What does all this really mean, then? In what ways does the horn 'help' the driver/transducer. And how does all this make horn drivers a bit different from direct radiators? I will try to sum this up in a few points: -Improved energy conversion means that for a given SPL, a horn loaded diaphragm will have to move less than a direct radiating diaphragm of equal size. For any electromechanical transducer, the distortion generated by the driver itself will be proportional to diaphragm excursion magnitude. Thus, for any given SPL, the horn loaded speaker will have lower distortion than the same size direct radiator. -A smaller diaphragm on a horn can be used to generate the same SPL as a larger direct radiating diaphragm for the same excursion amplitude. This means that you have a smaller mass to accelerate for the same acoustic output when you horn load a driver. This helps the transient response of the speaker regardless of what Fourier said. Subjectively, horns will be noted for their effortless, snappy handling of transients. -The smaller diaphragm excursions allow the use of short, underhung voice coils (reduced mass again) taking full advantage of the flux in the pole piece gap. This increases the efficiency of the transducer, allowing the amplifier to work with more headroom and greater ease. Horn drivers need to have powerful magnets and tight magnetic coupling because of the high pressure they are asked to produce when sitting in a horn throat. -Because the amp has more headroom, and because the driver handles signal peaks and high outputs more ideally, horns will be able to produce much higher SPLs than comparable direct radiators before distortion becomes objectionable. In short, there will be room for more dynamics, at lower distortion, with better transient response, with less stress on the amp. Since this is an enthusiastic pro-horn text, I have not emphasized the problematic aspects of horns. One thing I haven't mentioned is that the lower the frequency one wants to reproduce through a horn, the larger the horn must be. The size of a horn quickly multiplies when you go down a few octaves. Bass horns can be next to impossible to fit into a normal home. This really shouldn't be a problem to a true enthusiast, but even I have had to postpone any dream of a bass horn until I get a bigger place to live. Some people say that horns have 'horn sound'. I'm not sure but I think what they mean is a sort of megaphone-like quality to the sound. A good horn should not have any of this. Unfortunately, many bad horn designs have led people to think that this is how horns 'are supposed to sound'. To the true horn fan, 'horn sound' will be a compliment that means, clean, dynamic, 'fast', physical, detailed and present sound. Admittedly, there are a few things that horns don't always handle quite as well as your typical small direct radiator speakers. Particularly the much hyped concepts of 'imaging', 'neutrality' and 'transparency'. Horns will often lean towards a more 'solid' (as opposed to 'transparent') presentation with more 'body'. (Less ghost-like if you will!!) And horns will definitely not sound laid back! The music will jump at you rather than shyly hiding some place far behind the speakers. Anyhow, horns have their problems like any kind of speaker, and can be extremely sensitive to the room and the rest of the system. The enthusiast would say that the advantages outweigh the disadvantages and that the problems are challenges.

If you are going to stay with a solid state amp, then I highly recommend the MIT Biwire 2's. I used them for a long time. With a solid state amp and horns, the MIT's known tendancy towards warmth and a slight softening of the treble is welcome. Biwiring, good for SS, not so good for tube amps. There is a much longer version of the following by Jon Risch, but trust me -- you need to know how to use a freaking slide rule to know what the hell he's talking about. *What is bi-wiring? Bi-wiring is where the crossover inside the speaker has been separated into it's HF and LF sections, and separate pairs of connecting terminals provided to access those separate sections independently. Normally, the LF and HF crossover sections are in parallel, connected internally to the same single pair of binding posts. For single cable use, a set of jumpers is provided to bridge the terminal pairs, paralleling the separated crossover sections outside the cabinet instead of inside. Then, separate speaker cables are run from the same amp output to these separated pairs of terminals at the speaker. *What good does bi-wiring do? Some say that any improvement in the sound it makes is strictly due to the decreased total DCR, and this makes the speaker less prone to frequency response variations due to cable resistance. According to this view, simply running the two cables in parallel at both ends will do the same thing. In my opinion, this is a very simplistic and incomplete way of looking at the situation. Once the crossovers have been electrically separated, they present different impedances (loads) to the power amp within their passbands and outside of their passbands. The woofer and corresponding low frequency crossover section will present a low impedance at low frequencies and a high impedance at HF, while the tweeter section will present a low impedance at high frequencies, and high one at LF's. With the electrical separation, differing currents will flow within the two cables that make up a bi-wire set. For the separate cable feeding the woofer section, a lot of current will flow at LF's but not much current at HF's, and the tweeter cable will have some current flow at HF, but very little at LF's. A division of labor has occured with bi-wiring, whereby a single cable does not have have to carry the HF currents simultaneuously with the LF current. Two things happen due to this: 1. The losses in the cable due to "eye-squared-are" losses (current squared time the resistance equals voltage drop) are reduced for each frequency band, so that any tendency for the woofer to modulate the tweeter due to current draw is greatly reduced. This form of IM would be in lock-step with the original signal. 2. The magnetic fields due to the HF and LF currents have also been separated out, and any tendency for them to intermodulate and cause sonic artifacts has been greatly reduced. This form of IM would be occuring both at the same time, and in a time delayed form due to mechanical resonances and motor/generator action.

LOL, ain't it fun? No, pounding bass is not the EL-34's strong suit, but magic midrange and 3D texture is. I've never been much of a bass freak, and my sissy ears really appreciate the warmth and additional fat in the middle. I really dig the EL-34.

I would love to have those Artto, I could use them in my Cary preamp.

Tom, aren't most of the speakers in the pro-line designed for behind the screen applications? At any rate, most listening rooms just won't accomodate speakers of that size. I wish you lived closer, and I wish I didn't work 64 hours a week. I just can't believe you would listen to my rig and say it doesn't sound 'horny', or think it didn't bring some of the good stuff.

That's a good point.

I stand corrected. Here's what he said, in case you were curious. "These things (Jensen PIO's) are unquestionably a total rip-off! The thing measured 2.099 uF with a quality factor of only 200! In contrast, I have measured many Hovland MusiCaps and have never found one yet that measured below 2000. More musical, baloney! They are simply so lossey that all you highs go away as heat inside the capacitor! This is equivalant to connecting a .38 ohm resistor in sereis with a Hovland MusiCap. My advice -- DON'T USE THEM! "Quality factor" is the same as "Q". It's defined as the ratio of capacitive reactance (pure capacitor effect) and series loss as represented by a simple resistor. A 2.2 uF cap has 1 / (2 Pi F C) ohms reactance. At 1000 Hz, that is 72.34 Ohms reactance. A Q of 200 means there is .362 Ohms of loss inside the cap. That is, 72.34 / 200 = .362. A similar Hovland Musicap will have an internal loss equivalant to a .036 Ohm resistor. think that's why Hovlands have thicker wires coming out of them. The wires become a significant part of the loss. With the Jensen, who cares about the leads, they can be small because the loss in the cap is so much. One reason the Jensen caps may be used in tube amps is becasue they are rated 400VDC. The Hovlands I use are only rated 100VDC. For crossover networks, you could use 25VDC caps and be safe. Also, in an amp you in an "active" circuit. This means losses are not a problem. You just turn the volume up a bit to compensate. In a filter, like in a crossover network, the frequency response and input impedance get loused up! Losses are usually highest at the points of maximum group dealy, That happens near the crossover itself. Specifically, about the 1 or 2 dB down point on the skirt of each filter." Al K.

Sure it matters. If you get them backwards, the tweeter will be out of phase with the rest of system.

Oh my, what have you done? Just cancel the order. Man oh man, do you have ANY idea what even a set of RB-5 II's and a good sub or two will do?

It can also simply be a thing used as a baseline. If being used in the context of a measuring stick, Klipsch may simply have just been issuing a challenge to all the wanna-be 'reference' speakers on the market --

Probably a thousand posts on this. No one can predict which you would prefer. It's simply a matter of personal taste. Each has their strengths and weaknesses. Even the mighty Klipschorn is not 'perfect'. I will say that Heritage is much more sensitive to amplification and sources. The midrange horns are brutal, and reveal everything. Heritage can be either demonic or angelic, all depending on what you feed them. Reference is just a different animal. The two-ways are much more tolerant of imperfections in the chain. However, they also respond extremely well to upgrades, and if done right, can surpass Heritage in several areas. I am an RF-7 freak, and feel confident in telling you that staying on the Reference path can be very satisfying in every way.

He's on the level. It's all about point of Reference. I remember when I thought Advents were the end all, then I heard DQ-10's, then I heard Magnepans -- and on it goes. No doubt a set of SF-2's would crush the Acoustimash system. I don't think Reference or Heritage is available through Best Buy. If so, then I might get a part time job at Best Buy.

I hate Korn. Have always hated Korn. But 'Untouchables' is ground breaking. About damn time that band learned how to make music.

Craig can't render an opinion yet. He's in the process of kicking himself for sticking those POS Jensens in the ST-70. He's waiting on some Auricaps to stick in there. I just read that Al K thinks the PIO's are probably O.K. for amps, cause to compensate for the losses, all you have to do is turn it up more. Now Craig, I KNOW you know how to do that!!

Nice Job. Yeah, the wood is cool. Very nice. I second the Auricaps...big time. As for something like the Cardas posts versus the terminal screws -- which of the two are more like wire? The terminal strips and screws are very low mass, and more likely to pass the signal cleaner. Anyone buying that? I didn't think so.

Welcome to the forum Winford. Someone should be along soon to help. You just threw me a curve ball.

Well... you can do it right here, or you could also use www.audiogon.com

Now see, what did I tell you? "Oh ye of little faith."

Sorry Artto, that's not a link. I just cut and paste what was on Brent Jesse's page. You'll have to scroll down to see the text I copied. No picture. You'll have to email Brent and ask him. I trust him implicitly. http://www.audiotubes.com/12ax7.htm Thanks Marvel. I'm sure you know there are at least a dozen 5751 types, and they all have a somewhat different signature. I've seen Sylvania 5751's for $50 a piece!

Your diaphram is fried. You can replace it yourself for $25, or send it in to be done for you. Call 1-800-511-3343, or email info@simplyspeakers.com -- tell them you need to have the diaphram replaced in your K-77 tweeter. Get a qoute. Chill, everything will be cool.

Thanks Allan Artto, are these them? 12AX7 / 7025 Japanese made New Old Stock in original and whiteboxes. Nice tube, similar to Mullard in construction. Most made at the Matshush!ta factory, which was set up by Mullard U.K. $10. Several are 7025, add $5 to price. I've been doing quite a bit of reading on tubes as of late. I started doing more research after realizing how good the 5963 RCA Blackplates sounded that Edmond sent with the Cary. With the Mullard EZ-81's in the preamp, I actually prefer the 5963's over the Telefunkens. The 5963 is basically a low gain, low noise version of the 12au7. The tube has about 70-80% of the gain of the 12au7. Reading through Joe's Tube Lore at the Asylum, I found out about the 5751 as a replacement for the 12ax7. Same story as the 5963 and 12au7. A tube designed to overcome some of the problems with the 12ax7. Low gain, low microphonics/noise design. Any history with the 5751 and the Scott? Any opinions here on this? From Joe's Tube Lore: After reviewing most of the 12ax7's, he goes on -- Well I've just run roughshod over some of the most revered tubes in the NOS universe and basically damned them with faint praise at best. So what do you do if your gear has a couple of sockets that expect to see a 12AX7? Well I would propose that you cast an eye toward the 12AX7s more refined and altogether superior offspring - the cheap, lowly 5751. In its day (it was introduced in the mid '50s) the 5751 was created as premium 12AX7 designed by US manufacturers to overcome the well known limitations of American made 12AX7s, specifically: huge sample to sample variability, microphonics and noise. The fact is this tube had considerable care exercised in its design that is evidenced in its physical construction: Rigid metal rods linking the mica spacers for a more rigid less microphonic tube, a third mica spacer to brace the getter halo (again to combat microphonics), careful testing to assure consistency tube to tube and lower mu (apparently to combat noise) which results in an altogether more focused & palpable sound. But then a funny thing happened. This tube was made in massive quantities by companies like Sylvania, RCA, GE and Raytheon and was supplied to the US military resulting in massive JAN stocks of NOS tubes lying about. Just not the sort of exclusive limited availability tube that exclusive NOS tube dealers could charge $ 50 a pop for - like those rare & exclusive Tele & Mullard 12AX7s...So a premium tube with great performance and a genuinely careful design has knocked about as a common $8 NOS plug in for 12AX7s while its less capable but better known 12AX7 competitors have achieved legend status. Now all may not be well in audio land here so I'll warn you now. The 5751 has a lower mu than a 12AX7 and some circuits purportedly don't abide by that but I've tried them in 4 preamps with no problems and this guy has found pride of place in a lot of tube preamps over the years CJ used them in their line stages for years and Joule Elektra ran them in the LA 100 / 200 series of preamps until very recently - so there are other people have heard the merit in these guys too. So if the 5751 is the direction to look, where do you start? Well there are several choices and vintages (most of which are ridiculously cheap) that will put a Tele or Mullard 12AX7 to shame... http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7

You're also running 3 Heritage big boys and a pair of Heresies with that getup. I'm running one set of RF-7's with 60 wpc. The significance here (and Craig and myself were just talking about this), is that I haven't been able to approach near this level of control and cleanliness with anything else I've had. If the low power folks are right, I should have been able to reach this level with 16 wpc. I couldn't get it with the Apollo SET amps (18 wpc), and I couldn't get it with the triode, all Class A, 35 wpc AES AE-25 Superamp DJH. Both of these amps would begin to sound pinchy and strained past 95 db. I could get 100-105 db -- but it wasn't enjoyable to listen too. The Quicksilvers are fierce sounding, and at 105 db -- are very LISTENABLE. It's not just about the loudness, but also how good it sounds riding those high waves. I've concluded that though horns don't need much power to sound good, or to get loud -- they do benefit from additional power, so they can sound good while playing loud. Horns benefit from headroom just like any other speaker. Reference needs at least 40 wpc, and Heritage, should be run with at least 20. Those of you who listen to elevator music or Jazz, can probably throw these numbers out the window.

I was kidding about donations, I certainly wasn't expecting anyone to donate tubes! After I finish paying Edmond for the SLP-90, I'll start scrounging money together for the tubes. Of course Artto, if you're independantly wealthy, and those Telefunkens are just collecting dust... I'm glad you don't hate everyone anymore Allan:) I can't see eBay from work -- what is that last link all about?

I wonder where they possibly could have come up with this idea. http://www.klipsch.com/listeninglounge/