Why not horns?

I'm sure there are a number of people who have done extensive listening on very good horn systems who prefer something else, but my guess is that most people who "loathe" horns have never heard them properly implemented. Kind of like saying hamburgers suck when the only place you've had one is McDonalds.

.

Good question, but you could extend that to just about anything else in this hobby. I went through probably 10 pair of some pretty high end speakers before I settled on what I have. Other than changing to bass horns and going from standard to Duo Omegas I've had the same basic speakers for probably the past 6 years and have no desire to change. They make me smile, they make me tap my toe.

.

I am amused. Those that think every sound coming from horns sounds like air blowing through a horn have evidently never heard good ones.

If you want violins to sound like trumpets, get horns"

That statement shows a complete ignorance of what a good horn system sounds like.

The violins through mine are indeed violins. I attend the philharmonic on a regular basis and even though there is no way to completely reproduce that experience in your home, my system does a pretty good job of reproducing a symphony orchestra. I assure you it does not sound like a bunch of trumpets.

Ralph, do you wind your own field coils? I'm not sure he has them on his website yet as they may still be in development but I've listened to some that Jeffrey Jackson and Dave Slagle are developing and they do indeed sound very nice.

http://www.jeffreywjackson.com/

.

Dartford, I accept your assessment of what you heard. I am curious what horns you have heard. I realize that might be an extensive list and not worth the bother of recalling but given our diametrically opposed experiences it might help understand where you are coming from.

Macrojack, I would add Jeffrey Jackson and Dave Slagle to your list of cutting edge horn designers. Jeffrey is distributing a line of wood horns and they are collaborating on field coil designs. Check out the Hi Fi Heroin blog at this link to get an idea of how consumed these guys are with it.

http://www.jeffreywjackson.com/

.

Johnk, Looking at your system it raises an interesting question, what is a horn loudspeaker? In my mind you have a hybrid system that uses some principles of true horn design with more conventional non-horn characteristics, like the bass module and the super tweeter. Not that there's anything wrong with that. BTW, what's the tweeter. Is there a horn in that box?

To be a true horn IMHO the horn must be long enough to actually load the driver. Having a flared opening does not make it a horn. An example is what Avantgarde calls a Bass horn. It is really a woofer with a flared opening. The length of the flare is way too short to have much impact on the driver. Another hybrid would be a Lowther in folded horn cabinet where the vast majority of the frequencies are produced directly from the driver and just the bass comes from the folded horn.

Wonder how many who dismiss horns have never really heard a true horn?

.

they suck the life right out of the music

I sit here tapping my toe, rocking back and forth with a big grin. The life has not been sucked out of the music. I get the same response from seasoned audiophiles as well as complete newbees who sit slacked jawed never having heard a high end system.

I think this is one of those situations where we can't discuss it with words. You need to hear what is going on over here.

.

Mapman, that system looks impressive but that big white "bass horn" with the big driver is not a true bass horn. My bass horn is 16 feet long and gets down below 40 Hz. That is simply a woofer with a flared opening.

Jhonk, I realize how physically large your woofer cabinet is but I am one of those who would not call it a horn. You are correct though that there is no need to debate that. It's yours, you can call it whatever you wish. You are also correct that to go down to 15 Hz a basshorn like mine would have to be much, much longer so if you want to go that low you have made what I would call a good compromise. Getting down close to 30 is low enough for me so I don't have bass envy.

.

I'll chime in on the digital crossover question. My basshorns are 16 feet in a 28 foot room. It would be theoretically possible to physically time align if I sat against the far wall but for the sake of space I use Pure Vinyl running on a Mac Mini with an RME Fireface 400 which allows me to have digital time delay. It digitizes at 24 bit 192 Khz and does its calculations at 64 bits. By eliminating an analog RIAA and doing it digitally I avoid the phase shifts at the knees that analog RIAA networks must have. All in all I think it is an excellent compromise and sounds truly wonderful.

Wouldn't it be nice if we could all stop by for a listen to each others systems?

.

.

Macrojack, the folded horn you asked about is one of a thousand variations on the same idea. I can't speak to that particular model but as a general design it works pretty well if done right but has a few problems. You have parallel side walls which means you have resonant frequencies and it really doesn't flow like a what I would call a true horn. If you look at mine it is expanding in all directions as you go from driver to mouth so no parallel walls and no sharp bends like in a folded design. However, the folded horn is a good compromise.

Lokie, as you realize it is difficult to describe sound but the best I can think of is a box is muddy compared to a horn. Not that good subs sound muddy but horns are just a bit better. I think it is usually described as the horn is faster but I'm not sure what that exactly means. If you could hear one you would understand but unfortunately they are few and far between.

.

Johnk, do you have a link to that. I assume you aren't talking about the system you have posted here.

I have my own ideas but what do you mean by forward and laid back? I would not describe my horns as forward. I would say the are transparent and very revealing so bad recordings are revealed as such.

.

Mapman, I see, then my horns are very laid back using your definition. IMHO this has everything to do with how speakers are place in the room and very little to do with the type of speaker. Don't let comments like those from Unsound dissuade you. You may not end up liking them but with 10s or 100s of thousands of us loving them they must have something to offer.

Rleff, Time align means that the sound waves from the different drivers arrive at your ear at the same time. Imagine a whack on a drum that was partially produced by the woofer and partially produced by the mid range and just to exaggerate imagine that the woofer is sitting 100 feet behind the midrange. You would hear the higher frequency part of the whack and then about a tenth of a second later hear the low frequency part of it. That applies to all speaker systems with more than one driver but it is exacerbated with a bass horn since they are so long.

In order to physically align my drivers the mid-tweet horns would have to be 16 feet behind the mouth of the woofer. I choose to digitally delay the mid-tweets instead of moving them.

Unsound, I guess that's why there are different types of speakers. I've never heard a Thiel I wanted to listen to for more than a few minutes. I've never heard the upper level Vandersteens but the 3A sounds to me to the slowest speaker in the world. I end up leaning forward trying to get to the music. Others say they sound wonderful. Go figure.

.

Macro, you are a bit off base on that one. It is one of the common misconceptions in audio. Your description of being physically aligned is correct but your description of phase and polarity isn't.

A difference in phase means a difference in time. A difference in polarity means one signal is going positive while the other goes negative. Phase and polarity are two entirely different things.

It is confusing because if you reverse the wires on one speaker (black to red) in a stereo pair then everybody says the speakers are out of phase. That is technically incorrect. The correct phrase is you have reversed the polarity to one speaker. One will be going in while the other is going out. They still happen at the same time so they are in phase but they move in opposite directions so they have opposite polarities. Unfortunately it is common practice to describe it as the speakers are out of phase, and it is awkward to say that one has its polarity reversed, so we are stuck with a phrase that is technically incorrect.

Same situation with balanced cables. While one line is going positive the other is going negative. Some people incorrectly say they are out of phase but actually one has inverted polarity.

If the speakers aren’t time aligned then there is indeed a phase shift, a difference in time.

.

Ralph, I'm glad we have found common ground on the horn issue after butting heads on single ended Vs. balanced, and I understand your point about phase shift in crossovers, but trying to do time alignment by phase shift in crossovers seems to me to be a hopeless affair. The amount of shift is frequency dependent so while I suppose you can shift a driver closer to another as you approach the cutoff frequency wouldn’t that leave you out of phase in the passband of each driver? I’m no speaker/crossover designer so maybe I’m missing something.

Phase shifts can occur because the drivers are different distances from your ears. This can be corrected physically with driver placement. That's one reason you see speaker boxes that slope back to get the tweeter voice coil aligned with the woofers. That's pretty easy to do or you can do the digital delay. If you look at various front loaded horns you almost always see that they are built with the mouths of the horns different distances away from the listener to align the voice coils.

The harder problem is phase shift caused by crossovers. In a simple first order crossover as you get close to the cutoff frequency you also start getting a phase shift. At the cutoff frequency there is a 45 degree phase shift. Different frequencies get shifted by different amounts. There are other filter configurations that have less or more phase shift but each is a compromise in some way.

I use a digital crossover and delay that they say has no phase shift but I tend to believe it must be screwing with the signal in some other way. I don't know enough about digital filters to prove that but I'm in the "you don't get something for nothing" camp.

.

I love the tuba, ever see those shows with a hundred tubas?

magical.

.

I'm glad to see we agree that horns are magical.

.

phase shift via non-dispersive polarity inversion

I'm going to remember that so I can completely confuse somebody the next time this topic comes up :>)

the word Phase describes a relationship it can be applied to anything really

Weseixas, Phase and polarity have very definite meanings in electronics. Just because phase has different meanings in different contexts does not mean you can use it however you want in a scientific discipline like electronics and be correct. In electronics phase has a single meaning. To say things are in phase means they happen at the same time. Out of phase means the time relationship between two signals has changed. One is occurring later in time with respect to the other. A polarity inversion means what was negative is now positive and vice versa.

When you put an audio signal through a crossover there is a phase shift at the crossover point. Some frequencies are shifted in time. No polarity change of anything. Phase dispersive as Almarg described it.

Like I said before, even though it is very common to call a polarity inversion at a speaker out of phase this is technically incorrect. There has been no timing change, we have only inverted the polarity. It is common because for a single frequency a polarity inversion and out of phase 180 degrees gets the same result (see below) but just because it is common usage does not mean it is scientifically correct. We're also not dealing with a single frequency in audio.

We say that the sun rises in the east and moves across the sky. Is this scientifically correct even though everyone says it. No, the earth rotates, the earth is moving, not the sun.

At the end of the day does it really make any difference if we say speakers are out of phase? In that context no, since everyone does it so we all know they mean the leads were reversed. The problem arises if you try to expand your knowledge of electronics and continue to confuse the two terms.

Please see the link below which says exactly what I just said. Notice the author points out that polarity switches on audio equipment are sometimes incorrectly labeled phase switches. This is exactly the same error committed when we describe switching speaker leads as out of phase.

Almarg said, "A polarity inversion is the same thing as a 180 degree non-dispersive phase shift."

It may appear that way on a scope for a single frequency but if you have a complex waveform consisting of more than one frequency you get different results. Two scenarios

(1) Take 2 signals of equal amplitude and the same frequency that are in phase...

...polarity invert one and sum the result you get complete cancellation.

...phase shift one signal by 180 degrees and sum the result you get complete cancellation.

Same result but for a different reason.

(2) Take 2 equal signals consisting of a mix of 20 hertz and 100 Hz all the same amplitude in phase....

.... polarity invert one and sum the result you get complete cancellation.

.... phase shift one signal by 180 degrees...well... here is where you run into a problem. You can't phase shift them both by 180 degrees because the periods are different. a 180 degree shift of 20 Hz is 25 milliseconds and a 180 degree shift for 100 Hz is 5 milliseconds. You can't phase shift them both by 180 degrees.

Conclusion... phase shift and polarity inversion are always 2 different things even though under special circumstances you get the same result. Sorry I got a bit long winded. Phase/polarity confusion is a pet peeve of mine.

http://www.musiciansfriend.com/document?doc_id=91427

.

Ralph, yes, if you look at my system you see I have a big problem with time alignment. The woofers are 16 feet long and I decided that a digital delay was worth a try. First I tried a Behringer DCX2496 which was heavily modified to bypass the crappy opamp outputs and poor power supply and digital clock. The results were very good but that left me with another problem...how to deal with the analog input from my phono stage. The DCX does ADC but the mic preamp wasn't very good and bypassing lowered the input impedance too much.

That's when I discovered Pure Vinyl software. It does what the DCX does but using a much higher quality RME or any interface you choose. The cartridge feeds direct to the mic inputs on the RME. I was very skeptical at first, people who I really trust told me there was no way it would work...there wasn't enough resolution at the high end and you would just end up with square waves at higher frequencies...but I tried it and lo and behold it does work. I digitize the vinyl at 24/192, the PV does the RIAA EQ with a wide variety of curves, and I feed it back out at 24/192 to biamp. I haven't played with the plugins very much but you can fiddle with EQ curves and slopes and cutoff freqs and whatever else to your heart's content. PV has a built in 2 way with a variety of slopes and time alignment but with plugins not only can you tweak the crossovers in an almost endless number of ways but you can do it in a few seconds to see what you prefer.

AND, I have a 107 dB or so horns with SET amps and with the vinyl input turned up I have almost zero noise.

I know, the analog purists in the group dismiss this immediately. They've never heard it but are convinced it won't work well so they wouldn't even consider it. That's fine. After many years of chasing the dream I have a system that makes ME very happy. I used to sit and wonder what I could do to improve it, Now I just sit and enjoy the music.

Stop by anytime for a demo.

No matter what his rational for doing so what you have is an approximation of a horn. The reason for doing so is simple. It is much easier to make a wooden cone with flat panels than a true horn. From what I've read these compromises really become audible as frequency increases. I have no basis for this conclusion other than logic as I have never heard your cones, but if an approximation of a horn is good it seems logical that a true horn would be even better.

What's the price on yours? I can't get the link to work.

Macro, you should look into getting a true horn for that compression driver. What you have looks more like a megaphone than a horn. I don't doubt you are pleased with the sound from it but I wonder what it would sound like with what I would call a true horn.

The elevenhorn web site is a bit weak, hard to navigate and not much info, but I don't think anybody is selling horns like these.

http://www.jeffreywjackson.com/

this thread has been going so long I forget if I've already posted this

Is that for the horn or the horn + driver? If for the horn that's pretty expensive. You can get a solid wood horn from Jeffrey for a whole lot less.

I tried http://www.acoustichorn.com on 2 computers and can't get anywhere.

It would seem that you have set an arbitrary picture in your mind of what a horn is to the exclusion of any variant.

Not really. You can see from my system I have 2 variants. If possible I would have constructed the bass horn as a continuous flare but it would have been impossibly difficult. From what I am told by people who I trust a flare is better than a cone.. I am open to other possibilities.

I didn't say yours are bad, I simply suggested you might want to explore other possibilities. You seem a bit defensive.

.

Hi Terry, you are a known to be harmless wacko so welcome at any time :>) I had lunch with Nathan last month and he seems to be doing well. It would be nice to get the old gang together. I can accommodate a small crowd but need to get my wife out of town for a few days.

.

Ralph, is that a fair comparison? Dismissing DSP in the home because the master tapes sound better in the studio? I've got a ton of 44.1K recordings that DSP can only hope to make better , not worse. My computer is doing 64 bit calculations on my files to produce crossovers with no phase shifts and time align my drivers at the same time. I can use all manner of EQ plugins if I wish to improve what are often marginal recordings. Since I don't have the original analog files I think it is great way to go in the home.

M'Jack, you know I post things like "stop by" and then get to thinking about all of the wackos on the internet (not you) and get nervous about having strangers stop by. Call me paranoid but you never know. John Wayne Gacy seemed like such a nice guy.

RME is a company that makes pro-audio interfaces. There are a lot of options..Lynx, Aurora, Weiss, etc.

Pure Vinyl is pretty easy to use but any software that is flexible is going to have some sort of learning curve. Once set up you just boot it up. It runs on Macs so you are halfway home.

My friend has meticulously set up his Trios with 3 pairs of bass horns in a dedicated and purpose built room with every little trick and room correction you could think of.

That doesn't mean he did it all correctly, only that he spent a lot of time and money doing it. Maybe he has, maybe he hasn't?

Are those the huge Avantgarde basshorns? I haven't heard them but they really aren't horns. A horn does not require a 250W amp. Those are woofers with a flared opening.

.

Sarcastic, not at all, why would you need a 250W amp with a high efficiency speaker like a horn? I use an 8W amp with mine but it is a bit of overkill.

.

El. he had a headache after the show. Pinning the cause down to a single room at the show seems a bit of a stretch to me.

Prez, that still doesn't mean he had it optimized, and it isn't anywhere near the same place as a horn no matter how many you stack up.

.

Oh, I meant to speak to the meticulous set up in a purpose built room. I once went to audition an amp and the guy had a purpose built room to the point of having non parallel walls and reinforced floors. He had a $75,000 Ongonku amp and their silver step up connected to his reference turntable, whatever Fremmer was using at the time. Room tweaked to nth degree and no expense spared.

He was surprised when I pointed out his speakers were out of phase. My point being if a supposed audiophile can miss something so glaringly obvious it is extremely easy to miss some fine point in the set up that takes it from sounding very good to making it sound right.

.

I'm confident my own 20+ years of professional experience is enough to say that he has those horns as "optimized" as they will ever be.

I think you missed my point. It is impossible to ascertain whether or not they are optimized especially just by listening to them occasionally. You can describe the sound, you can say they sound good or bad, you can say they are too bright or too whatever or not enough of whatever..........but you can't say they are optimized unless you have tried every possible combination of every variable. Yes, kind of ridiculous in a way but that's what it would take. I think my setup sounds pretty good but is it optimal? No, just like everybody else I got to a point and quit trying for now. I'm sure when I revisit it I can somehow improve it.

The overall sensitivity pretty much matches the other three horns, which is the point anyway. (right?)

No. Very different. If it takes 250W per driver to match the output of 1 or 2 watts per driver then the sensitivity is not even close. One of the beauties of what I would call a true horn is the fact that you can get a lot of sound with very little power. In fact, needing that much power is a dead giveaway that it is not a horn. Going to 20 Hz has nothing to do with it. It's how you get there. Mine only go into the 30's but they do it with a few watts. A very different beast than doing it with twelve drivers and 3,000 watts. (I got that from 3 pair = 6 with 2 drivers per. If my math is wrong then please adjust but I think you get the idea.)

how did you time align, physically or electronically?
.

"too large footprint" is relative. I have plenty of room.

"poor bass" is just plain wrong. I bet you a donut I'm getting better bass from my horns than you are from those tiny Thiels.

.

Wes, you are correct, it will never be settled here, but why would one need more power if what one has will cleanly go to rock concert levels?

The all things being equal is the problem. If one believes that an SET is the best route then you can only get a limited amount of power. Everything is a compromise and I'm happy with the compromises I chose.

Dan,

The fact that there is a horn connected has nothing to do with the power requirement of the driver.

Is that really what you meant to say? It has very much to do with it. The very reason we use horns is to raise efficiency.

http://en.wikipedia.org/wiki/Horn_loudspeaker

Are you saying that seismic sub is 110dB efficient? I can't find anything on the web, his site is down for construction. I saw where he recommends 100-200 watts. If true it is hard to believe it is 110 dB efficient.

If you had a front loaded horn that was sufficiently long you could get those bass notes with very little power. Sorry if that irritates you but it is the truth.

Prez, so there is nothing you could possibly do to improve the sound of that system? If it is optimized that is what you are saying. Optimal is as good as it gets.

How do you figure the efficiency of the "basshorns" given it is an active system?

For reference, this same guy with the Trios went from one 75 watt stereo amplifier to two 150 watt monos for just the top three horns. And it sounded better! Why, when he only needed 1watt?? For reasons OTHER than headroom.

I agree it wasn't headroom, so what was it? You are comparing 2 amplifiers that obviously have differences other than max power and saying it is definitely because they have more power. It seems you jump to a lot of conclusions.

Wes, I know nothing about this bass driver. You need to ask Dan.

I understand what bridging an amp is. If you bridge a 75W amp you get 300 watts if the power supply can handle it, not the 150 stated by paralleling it, whatever that means. Perhaps I misunderstood what he meant, that's why I asked him to clarify.

.

Prez, so one watt to the basshorns produces 109dB at one meter?

Identical in every way expect the fact that the monobloc has paralleled outputs.

Identical except it has more power and a different output impedance and just about everyone who has tried it says running a stereo amp in mono changes it's sound even if they are played to the same level.

BTW, If you take a 75W amp and run it as a monoblock you get twice the voltage swing so 4 times the power, not twice. What amps were these?

Wes, that is what Dan told us, I was asking him to clarify if that was what he meant.

I wish you could edit,

Prez, you said the outputs of the amp were parallel to double the power. It doesn't work that way. Please clarify.

.

prez, I think you are bit off base.

Bridging and paralleling are two very different things. Bridging effects the voltage. Parallel does so with the current. If a design can allow for paralleling you double the current thus doubling the wattage.

Assuming you aren't trying to draw so much current that the supply voltage sags then the max power is determined by the voltage rails. If you parallel two amps you get the same maximum voltage before clipping. If you get the same maximum voltage you get the same maximum power.

Two 75 watt amps with a given gain in parallel is a 75 watt amp with the same gain but capable of delivering more current into a low impedance load so it won't sag and clip as easily. Now that might explain why it sounds better.

a serious argument could be made that it is better to use 6 individual drivers to achieve the same sensitivity of just one and a huge horn due to the way the 6 different ones will average out their non-linearities.

Interesting theory but again, a little off base. You think if multiple drivers have different distortions that will add up to less distortion? You can't average out distortions.

A + B + C + D + E + F is less than A ??? I don't think so.

Now if you told me that 6 would distort less because each is working 1/6 as much therefore distorting much less then I would go for that.

I hate to be blunt but if you don't understand some of these basic concepts it kind of puts your other conclusions into question.

.

You then went on to explain it in , well, a simpler term , coming to the same conclusion that you originally denounced.

LOL...

I did not denounce his conclusion. I denounced his reason. I said something complete different LOL !!

Prez, I read exactly what you wrote. You said "6 different ones will average out their non-linearities. ."

That statement is false. Nothing averages. To average something you must add up each one and divide by the total. They produce less because they aren't driven as hard. Each one produces much less so the TOTAL is less. That is in no way, shape or form an average. That may be what you meant but that is not what you said. I'm sorry but I am not a mind reader.

Good GAWD !!

There is a lot I don't know about electronics but after teaching it for 10 years I do have pretty good grasp on the basics. Since you want to be condescending let me explain it to you in the simplest of terms.

To produce 75 watts into 8 ohms an amp must have rails of about plus/minus 34 volts. That give you peaks of 34 volts which is 25 Vrms. Square that and divide by 8 oms and you get 75 watts. P = V squared divided by R.

When you put things in parallel the voltage stays the same.

If you put 2 amps with 34V rails in parallel you get an amp with 34V rails.

Same volts = same watts.

You are correct that V x I= P.
Also V divided by R = I
With the same R and the same V you get the same I
With the same I and the same V you get the same P

He didn't change the speakers so the R stayed the same.
Sill got 34V peak amplifiers so that stayed the same.
Same V same R same I same power.

Care to retract your admonition to "Sit back, take a breather and learn something!!"

.

I completely understand the difference in parallel and bridged.

I completely understand that parallel amplifiers cannot double the power output. I remain confused that you insist they do.

I saw nothing on the BAT site that explains why their amps do this. Maybe I missed something.

I accept your apology

.

If you take 6 different drivers, unless they have perfectly linear transfer functions, they will all have slightly different responses. If they all have the same input signal their responses should smooth to a more linear response.

Sorry, a complete load of crap.

Are you serious? You add up a bunch of errors and the total error is less than any individual error?

You've already embarrassed yourself with your theory about parallel amps. Might be better to retire now and save face.

.

JohnK. there is no definitive definition of a horn, but your bass horn is a completely different beast than what most of us are discussing here,,,, a front loaded horn to increase efficiency.

Your back loaded horn derives a huge part of it's output directly from the 4 drivers mounted on the face of it with reinforcement from the back. That is a very different scenario from a front loaded bass horn that must be much, much longer to be efficient.

It's not that one is right and one is wrong, but they are different. Curious what the efficiency of your bass cabinet is?

Jack, I finally got the web page to come up. It is curious that we have Bill telling us how wonderful his horn is with no mention of an EQ and Duke saying they sound like a megaphone without proper EQ. I didn't go back and read the whole thread so I'm going from memory here so maybe I missed something but if the horn does require EQ to sound good you would think the seller would mention that.

Prez,

You said the power doubled. Since paralleling does not increase power as I demonstrated it was logical to assume you meant bridging since that is the only way to get more power. You scold me for not properly interpreting your mistaken idea that power went from 75 to 150 watts????

You've already proven you have no idea how amps operate with your assertion that the current doubles when you provide the same voltage to the same load. I do mean power, not gain. I completely understand the difference. Evidently you do not because paralleling amps does not affect the gain, it remains the same.

A distortion is an error and they do add up, they don't average. Two drivers distorting differently is more distortion than either driver by itself.

I've debated people like you in the past and will not do so again. You are now so hell bent on not admitting your mistakes you are embarrassing yourself with idiotic assertions.

Good day.

.

Prez, I got your email. Funny you should call me a complete and utter fool when I clearly demonstrated your idea about power doubling when an amp is paralleled is wrong. The link to BAT said nothing about the difference in the amps except one has more power. Distortions do not average.

This is going nowhere because you can't admit these basic ideas are true.

Please quit bothering me.

.

Al, I too was unfamiliar with the design of the circuit, but one does not have to know anything about it to know that it is impossible to get more power without more voltage.

Some are assuming that paralleled output tubes will somehow would drive more current into the load when we both know that for a given load the amount of current delivered is a function of voltage. These are voltage source amps, not current sources. I tried to explain this and as a result received an email telling me I was insolent, a complete and utter fool, and a coward.

So my interest was piqued and I sent an email to BAT. I figured maybe they used a higher tap on the secondary of the power transformer to get B+ up a bit. Close, but wrong. They do parallel the channels but as I've proven that does not raise the voltage. They also use a higher tap on the output transformer to raise the voltage. Very clever.

So for those who thought me to be an utter fool for saying you must raise the voltage, well, I guess we know who looks foolish now. Now that we have that settled I'll let the horn haters bash it out with the horn lovers.

Interesting thread, learned a bit about conical horns.

Oh, and distortions do not average out.

.

Prez, I hate to keep beating you down but your analysis with dB is also off

Not sure where you got 26dB but that does not equate to 400W. Here is how it works.

The sensitivity of the amp is 1V, that means it takes one volt to drive the amp to maximum output.

Of course these amps won't do it but to get 400W into 8 ohms you would need an output voltage of 57V. If you had one volt in that is a gain of 57. A gain of 57 is 35dB = 20 log 57.

To get 75W@8ohms you need 25V out. That is 28dB.

To get 75W@4ohms you need 17V. That is 25dB.

To get 150W@8ohm you need 35V. That is 31dB

I rounded things off but that is real close. It has a different amount of gain for each scenario because you use different taps on the output transformer to get different voltages.

.

Al, I wasn't questioning your analysis, you clearly understand the technical side of things. I was just trying to clarify the mystery of why this particular amp could double power when outputs were put in parallel.

BTW the specs for the VK-600 and others are on the website. The 600 delivers 300W/ch @ 8 ohms and doubles that into 4 ohms. I also checked on the power output when run as monoblocks. As we predicted, it does not double it's power output as a monoblock. I was told they can produce "somewhat" more power because the supplies don't sag as much. Again, consistent with what was previously stated.

Ralph, interesting info on the trios. I have Duos with the high impedance drivers so I assume it is the same scenario except the mid horn has no electrical crossover; the tweeter does. It looks to me from their brochure that the cap is in series with the driver which makes sense if you want to block low frequencies. I don't see how this would cause the impedance to dip to 4 ohms at high frequencies. Help me out here.

As soon as Pure Music releases a version with a three way crossover instead of just 2 way I intend to pull the tweeter crossover and try to run it straight to the amp like the mid and my basshorn are now.

sorry for three posts in a row but I missed this earlier.

Prez, I couldn't figure where the 26dB cam from but now I do. My earlier analysis was of the VK-75/150 and I did not know you were looking at the solid state amps.

If you take a look at BATs website and look at the following products: VK-255SE and VK-600. You will see that both amplifiers have 26dB of gain. Yet one is rated at 150W into 8ohms and the other is 300W into 8ohms.

The practical difference between these two amps is that the VK-600 is basically a chasis with two of the smaller amps fit inside. There are other differences but practically speaking, this is the crux of it.

Bottom line. I totally agree that paralleling identical amps does NOT change the gain (dBW) one bit. But clearly, BAT is a good example of how it does double the output power.

I believe you should see now that your conclusion is incorrect. The 26dB, as stated by Al just means the input voltage gets multiplied by 20 for both amps.

To get 150W@8ohms from the smaller one takes about 1.7 volts in.

1.7V times 20 = 34V......34V squared divided by 8 = 150W
If you drive it harder you can't get more than 34V because the voltage can go no higher and it clips.

To get 300 Watts from the bigger amp takes about 2.5V in which produces about 50V out. It can go higher because the voltage rails are higher. It has a power supply with higher voltage rails and presumably more output devices in parallel to share the higher amount of current it can produce. It's not higher power because it has more devices in parallel, it is higher power because it has higher rails. It is not simply 2 of the smaller ones in the same box.

You clearly don't have a firm grip on the basics yet you attack me for pointing that out. I don't know what to tell you. That's all basic electronics that a first year tech school student learns yet you call me a complete and utter fool when I explain it to you.

.

Unsound, I agree his posts are hard to read but your point isn't specific to horns and really has nothing to do with how they sound.

here doesn't seem to be a consensus by horn enthusiasts as to; when exactly a horn is implemented properly. Perhaps when that can be determined, the horn haters will give horns yet another chance.

Look how many variations there are with box speakers like you have. Once the box speaker enthusiasts reach a consensus I'll give them another try.

.