How much power is safe for Khorns?

[2Bmusic]

FIRST A FEW FACTS, so you can better understand my question.

 

I have been a Lascala Owner for about 2 yrs.  I was afforded the high honor of listening to Khorns being driven by Yamaha M80 Vintage amp,  ( ~ 260watts)    I NOW WANT KHORNS!!!!

 

>>Anyway, I AM WONDERING ABOUT POWER & HOW MUCH IS SAFE  VS WHAT MAKES FOR BETTER SOUND. 

 

With my back ground in electronics I understand that any device will only pull the amount of power it was designed to pull.

I also understand that you can turn up the power to insane amounts ( for that particular ) device and burn/ruin it.

 

I see  Khorns are rated to use 100 watts continuos and 400 peak.   ( not that one would ever listen at that level for sure) 

 

I also think that when the woofer needs power to move that air, it needs a great deal more than more mid and tweeter. 

 

1. Does it work that way?

 

2. If one were to connect a pair of 600 watt mono blocks ( in search of that holy grail of ultimate sound) , would that give more headroom than a 200W amp?

............ As long as the 600w mono blocks were not turned up to far,  would it be safe to use on Khorns?

My thinking is during peak passages where the mid and tweeter were needing 5~10 watts ( to reproduce their frequency range) ..... the Tympani hit would need 100 ~ 200 watts for that brief split second to reproduce the music faithfully. 

 

SO.... If the 600 mono blocks were not being pushed, the almost limitless headroom the speaker electronics were demanding  could result in great fidelity and so on and so forth. 

[DizRotus]

Theoretically yes, but practically no.  

 

Khorns will produce deafening volume levels with single digit wattage.  The headroom provided by 600 watts will not noticeably improve upon the headroom provided by 200 watts, or even 20 watts.

 

In the 70s, I used 4 Speakerlab SKhorns (same tweeter, squawker and similar bass bin as Klipschorn) in a mobile DJ biz.   They were ordered as 8 ohm to be wired in parallel pairs to provide a 4 ohm load to Dynaco ST 400 (200 watts/channel @ 8 ohm; 300 watts/channel @ 4 ohm). The young customers always wanted it LOUD.  For the most part, the speakers handled the power, which was somewhat absorbed by the long leads to the 4 speakers.  Nonetheless, on a fairly regular basis, I fried the voice coils in the T-35s (K-77).  A phone call to E-V in Buchanan, MI would have a replacement diaphragm in the mail.  I would simultaneously send a check (~$17) to Electro Voice, 600 Cecil St., Buchanan, MI.

 

It would be safe to use 600 watt mono-blocks if volume is kept to a reasonable level.  I would consider using them if already available.   I wouldn't go to any extra expense to purchase them over a lower powered amplifier with low distortion.

Edited February 14, 2016 by DizRotus

[Chris A]

>>Anyway, I AM WONDERING ABOUT POWER & HOW MUCH IS SAFE VS WHAT MAKES FOR BETTER SOUND...I also think that when the woofer needs power to move that air, it needs a great deal more than more mid and tweeter. 1. Does it work that way?

 

Moving mass effects dominate the woofer relative to midrange and tweeter compression drivers - yes.  But note, you're talking about horn-loaded woofers, which only have to move about 1/5th the distance to produce a certain SPL as they would have to move if they were being operated in direct radiating mode.  In general, the reasons why Khorns sound the way that they do relative to direct radiating loudspeakers (including Cornwalls, Heresies, and any other Klipsch loudspeaker using direct-radiating woofers) is because of that horn loading reducing moving mass effects significantly

 

2. If one were to connect a pair of 600 watt mono blocks (in search of that holy grail of ultimate sound) , would that give more headroom than a 200W amp?

 

I think that you're forgetting about the contributions of the passive crossovers to limiting the amount of electromagnetic force available to the woofers. 

 

I'd really recommend you thinking about direct coupling your woofers, midrange and tweeters to a digital active crossover (tri-amping) to control the maximum voltages instantaneously in order to avoid damaging the drivers--with the tweeters in particular the most vulnerable (limited to 5W music power). 

 

Here are the maximum power recommendations from Klipsch listed in 1977:  https://community.klipsch.com/index.php?app=core&module=attach&section=attach&attach_id=69980

 

Chris

[2Bmusic]

Chris,

Are you saying that any amp that puts out over 100 watts will damage the tweeters?

[Chris A]

I'm saying that you can't put more than 5W music power through the tweeters without risk of blowing the diaphragms, and using stock or aftermarket passive crossovers is a poor way to ensure that.   When using massive power amplifiers to drive your Khorns, you risk issues with the tweeters that you don't have to risk if you use a quality active crossover that has limiters available as part of its standard architecture--and at a much lower price than using a high power and high quality tube/valve amplifier or something similar.

 

What you are describing is really not what I'd recommend to increase effective power to Khorn drivers (woofers).  Look at the testimonials about bi-amping or tri-amping their Khorns including the thread that I linked.  No one that I know has gone backwards once they've hear the difference--which represents a much greater listening performance difference than simply increasing the output power available to the loudspeakers using passive crossovers--using any kind of amplifier topology.  You don't need to be dumping that much power into passives, when active crossovers allow you to use much lower power amplifiers to drive your Khorns and realize a significant increase in available power to the drivers, as well as separation of the electrical circuits to isolate the midrange and tweeter drivers from the mass-induced dynamics and electrodynamics of the woofer channels.

 

I don't recommend the lowest cost active crossovers from miniDSP, Behringer, or entry-level dbx Driverack.  The Yamaha SP2060 thread in the alerts section that I just posted is a much better choice, as well as any of the 2-in, 6-out crossovers from ElectroVoice, Ashly, or Xilica.

 

Chris

Edited February 14, 2016 by Chris A

[WMcD]

There are a lot of misconceptions here.

1) A device is going to absorb power in accord to the voltage delivered to it and its resistance. Until it fails.

We'll assume the K-77 tweeter has a resistance of about 8 ohms. So with 2.82 volts delivered to it, it will absorb one watt. And it puts out about 103 dB of sound pressure at 1 meter measuring distance. I've seen some figures, but generally, it will stand somewhat less than 5 watts long term, and then the voice coil winding burns out.

2) "Short term" is a term which sort of honors something pointed out by the review of the Forte. If we use very short bursts of voltage, tweeters can withstand much more power in the bursts before a voice coil winding melts. But the bursts better be very very short.

3) When talking about music, two things are going on. One is that the power or voltage or level is not evenly distributed over frequencies. You can see this on a real time spectrum analyzer. There is overall more power in the middle freqs. The good news for the delicate tweeter is that there is not much voltage or level up above 4500 or 6000 Hz. Two is that the duration is fairly short. The old Windows media player had an option to show this, maybe it still does.

4) The upshot of 3) is that it is easy to calculated how much power is being delivered to a driver if we use a single tone or frequency at a constant level. But music is not like that at all. IIUC some standards allow the use of pink noise. Essentially, there is less overall power in the treble, like music.

5) For example, a 100 watt amp is not putting out 100 watts at all times, though that is generally a maximum. We know that it is not putting out 100 watts in quiet passages, or they would not be quiet. (This is the dependence on the input signal.) Further, we control the power it is generally putting out with the volume control. (This is dependence on the controls.)

6) The overall voltage level to the midrange in the K-Horn and others is reduced by the autotransformer. (It would otherwise put out 107 dB or so at 2.92 volts. Also, the K-55 driver has thicker voice coil windings and will absorb about 30 watts (I've read) long term before burning out. But this is really hearing damage level.

7) The K-Horn / LS woofer does not need more than the 2.82 volts to put out 103 or 104 dB. Its voice coil has much thicker wire than the mid, and much much more than the tweeter. It might take 100 watts long term.

8) Looking at all the above, we see that a 100 watt amp just can't be putting out 100 watts into K-Horns (even though it is capable of it). Peaks would be 123 dB. That is not to say the amp is unusable. In the past I've posted armchair calculation that in quiet passages, the amp is putting out a microwatt. This is why we read PWK saying the world needs a good 5 watt amplifier. Others speak of the need for quality in the "first watt." Focusing attention on 500 watt amplifiers for quality is focusing on the wrong end of power output.

WMcD

[WMcD]

I had to look around my Win 7 media player.

Put a CD of your favorite music (or maybe other sources). You have to click on "now playing" icon at the lower right. Then right click to get a menu for visualizations. Then click on bars and waves.

You'll get a real time spectral analyzer. Unfortunately there are not indications of the frequency centers of the bars, but the price is right. Free.

Like I was saying, you will get an appreciation of the frequency distribution of your track and level.

[garyrc]

Some K77s (the tweeter used in stock Klipschorns, La Scalas, etc.) may take only 2 watts before failure, but in orchestral music the SPL of treble within the tweeter range is 15 to 20 dB below the average of the midrange and bass (so I hear).  Rock and electronic music may require extra caution.

 

Back when I had a power amp with a peak output meter, the loudest I ever had my Khorns was 25 watts per channel (the end of a Mahler symphony, outrageously loud).  A level of 15 dB below  25 watts (to estimate the power going to the tweeters) would be about 0.79 watts.

 

My 150 w.p.c NAD amps (more like 120 w.p.c. RMS) are much, much more than enough in our 4,260 cu ft room.  PWK said that 63 watts into a single Khorn would produce 115 dB in a 3,000 cu.ft room, and I believe it.  That would be about 0.5 watts to 2.0 watts into the tweeter with orchestral music, so that's about the limit.  THX, Dolby, Audyssey, and the movie industry specify a 105 dB ("full scale") limit per channel above 80 Hz, and allow 115 dB from subwoofers.

 

If you think you would go over safe limits, go with the advice Chris gave you. 

 

Known "tweeter killers" are high frequency test tones (keep them very soft), white noise (don't use it), fast forward or rewinding audiotape on tape players that don't provide protection, and the like.

 

EDIT:  O.K., the JBL graph (see link in BobK's second post) shows that power in the tweeter range is only 5 to 15 dB less than the middle frequencies, so be even more cautious.  I've seen 15 to 20 dB elsewhere.  I've had Klipschorns since 1982 and the only tweeter blown was because I didn't notice that the volume control was way up before I put on a test tone. 

Edited February 15, 2016 by garyrc

[twistedcrankcammer]

Another thing not being discussed here is that if you are looking for the greatest fidelity from your Klipschorns is that with multi channel amplification, you can add time delay into the tweeter and sqwaker.

 

Why would you want to do this?

 

Because that woofer in that Klipschorn isn't flush mounted to the face of the cabinet like a direct radiator such as in a Cornwall speaker.

 

Sound is relatively slow moving in comparison to light or electrical current. I am sure you have probably been to a fishing derby, county fair, or sporting event where you heard a time delay in the voices of two speakers because one speaker was a farther distance from you.

 

In the length of the Klipschorns Bass horn, we are only talking mili seconds, and although you don't realize it in casual listening, there is a smearing in sound of time overlap occurring that you can actually here if you do a direct A/B comparison, taking the time delay out, and putting it back in.

 

all of this thought line seems pretty silly to me about exactly how hard you can drive the Klipschorn without hurting it and still have acceptable headroom.

 

If you really want to listen at levels that loud, why not instead, run four Klipschorns, or better yet, 2 Bigger, more powerful Klipsch speakers that are more efficient than the Klipschorn, and capable of greater / louder sonic output such as the Klipsch TSCM, Klipsch MCM-1900, or Klipsch KP-600.

 

All three of those Klipsch speaker systems can dominate the output of a pair of Klipschorns.

 

Roger

[BobK]

I would not worry about too much power, you could hook a 1000 watt amp and do less damage than you would with a 20 watt amp.

 

When you play music it has peaks that need to draw power fast or the signal will clip into a square wave.  That is what heats up a voice coil and damages it.  If you have headroom you are never going to clip the signal.   This is why people think a 20 watt tube amp sounds better than a 20 watt solid state.   The tube amp does not do a square wave clip of the signal it sort of a rounded square wave which actually sounds good (just dumb luck)  they both will distort when they run out of bandwidth but tubes clipping is not as hard on the speakers and sounds better to some.

 

So clipped power or in rare cases too much can damage stuff.   Unless you are a goof ball with the volume and turn it up 100 percent I would err on the side of TOO much clean power vs having too little power and clipping the audio. 

[BobK]

I would read this article on power it also has a PDF that talks about too little power.

 

https://www.jblpro.com/pages/general_faq.htm

[2Bmusic]

It was upon those line that I was thinking about the 600 watt mono blocks .

 

Ok.   Here is the deal

1. I am a newby compared to most guys in here.

2. I was spoiled by my Snells and nakamichi stuff back in the early 80's.

3. Reading all this stuff is frustrating. At 63, i am looking for rather easy and quick fix to get great sounding music again.

4. So please be helpful and understanding.

 

BobK, what wattage then would be appropriate with reverence to that article? I am curious just for knowledge sake.

 

I would prefer less power with the idea that it will cost less. But the mono blocks emotiva has are 600 watts. They have very good specs and you can try and send back if you do not like.

 

I really like the idea of triamp or bi amp.  I have no idea how that is implemented. I would like to know how this is done.

Edited February 15, 2016 by 2Bmusic

[twistedcrankcammer]

I sent you a PM

 

Roger

[2Bmusic]

I'm saying that you can't put more than 5W music power through the tweeters without risk of blowing the diaphragms, and using stock or aftermarket passive crossovers is a poor way to ensure that.   When using massive power amplifiers to drive your Khorns, you risk issues with the tweeters that you don't have to risk if you use a quality active crossover that has limiters available as part of its standard architecture--and at a much lower price than using a high power and high quality tube/valve amplifier or something similar.

 

What you are describing is really not what I'd recommend to increase effective power to Khorn drivers (woofers).  Look at the testimonials about bi-amping or tri-amping their Khorns including the thread that I linked.  No one that I know has gone backwards once they've hear the difference--which represents a much greater listening performance difference than simply increasing the output power available to the loudspeakers using passive crossovers--using any kind of amplifier topology.  You don't need to be dumping that much power into passives, when active crossovers allow you to use much lower power amplifiers to drive your Khorns and realize a significant increase in available power to the drivers, as well as separation of the electrical circuits to isolate the midrange and tweeter drivers from the mass-induced dynamics and electrodynamics of the woofer channels.

 

I don't recommend the lowest cost active crossovers from miniDSP, Behringer, or entry-level dbx Driverack.  The Yamaha SP2060 thread in the alerts section that I just posted is a much better choice, as well as any of the 2-in, 6-out crossovers from ElectroVoice, Ashly, or Xilica.

 

Chris

Chris, Thank you for your comments.  I relate to what you are saying and find that this solution seems to be the best way to go.

 

So please explain what I would need, and where I can get the equipment.  I WILL BE BUYING KHORNS this week. Found them on CL in Baton Rouge, La. They sounded very good.

 

From what I have been reading ( most of the day today) I will need 6 amps , and one active cross over for each side.   Right?   What else? 

[2Bmusic]

I sent you a PM

 

Roger

I pm'd you back, but its 12:30 am.  I am exhausted.  Been trying to understand this all day long.  I have to work tomorrow... bit it is not a busy day thus far. I fix ATMS and similar devices.

[twistedcrankcammer]

Dave,

 

I just tried calling you twice, this wont take but a minute and I have a solution.

 

Call me back...

 

Roger

[twistedcrankcammer]

Dave lives in Kevin Harmons home town.

 

He doesn't know Kevin, but man is he in for a treat!

 

I am setting him up to meet Kevin so he can hear Jubilees in person and check out multi channel amplification for himself.

 

Maybe he will get to listen to mcm-1900 4 ways, KP-600s, TSCMs, and KPT-904s while visiting.

 

Should be enlightening to say the least.

 

Dave, I will call Kevin during business hours and tell him to expect your call after work.

 

Roger

[Coytee]

From what I have been reading ( most of the day today) I will need 6 amps , and one active cross over for each side.   Right?   What else? 

 

The active crossover depends.  What you would need for stereo listening is a crossover with two inputs and in this case, SIX (or more) OUTPUTS.

 

If you get something like you read here on the forum, an Electrovoice DX-38, you would need two of them because it is a 2-in, 4-out unit.  No need to buy two units if you can get a good unit that has six or more outputs.

 

In a sense, you should work backwards....  how many output channels do I need? 

[Chris A]

Chris, Thank you for your comments.  I relate to what you are saying and find that this solution seems to be the best way to go.

 

 

So please explain what I would need, and where I can get the equipment.  I WILL BE BUYING KHORNS this week. Found them on CL in Baton Rouge, La. They sounded very good.

 

From what I have been reading ( most of the day today) I will need 6 amps , and one active cross over for each side.   Right?   What else? 

 

 

You only need one active digital crossover: a 2-in, 6-out unit, like the one I linked above.  The cables used on these units are either RCA ("unbalanced") connectors, or XLR (balanced) connectors.  I recommend using the balanced connectors if they are available to eliminate common mode line noise (60, 120 Hz), even if you have to use RCA-to-XLR cables to connect with the upstream pre-amplifier and downstream amplifiers.  These are easily available at places like Guitar Center, etc. very economically.  Using one electric power wall outlet to connect your amplifiers, preamp, and crossover will eliminate any chance of common mode hum.

 

You need 6 channels of amplification, and the best quality amplifiers need to be on the midrange and tweeter channels.  The bass bin doesn't require as much fidelity, although some here might disagree. I've found that three good stereo amplifiers of moderate-to-lower power work well (i.e., less than 50W/channel).  The midrange and tweeter channels can be much lower power, although it's also okay to use all amplifiers of the same type, as I do.  You get somewhere between a 2x-4x multiplication of effective power by bi-amping or tri-amping, bypassing the passive crossovers.  Getting enough power just isn't an issue.

 

Typing in the settings (like the settings that I linked in the above Khorn tri-amping thread) is a snap taking only a few minutes.

 

Then sit back and listen.  It's not any more complicated than that.

 

Chris

Edited February 15, 2016 by Chris A

[2Bmusic]

I found this.   What do you guys think of this one?   http://www.parts-express.com/behringer-dcx2496-ultradrive-pro-digital-24-bit-96-khz-loudspeaker-management-system-cros--248-669

 

CHRIS, PLEASE RECOMMEND SOME AMPS!

I wish I could afford some used nelson pass stuff from Reno Hi Fi.  But that means even at used prices over $5,000 for two amps. 

 

What about the Nelson AMP CAMP AMP i was reading about in DIY?

 

It make so much sense to separate energy when it is at a low level, then distribute it to amplifiers.

It is Illogical to pump power into yet another device that must separate and also deal with power and its attendant, capacitance, inductance and impedance issues.   

 

I can not thank everyone enough for the advise. I will be calling Kevin today after 5:30.  I want to go listen as soon as possible. Thank you Rodger!!!

 

 

CHRIS... Please recommend amps.

The way I think I am beginning to understand is this: PLEASE CORRECT ME IF I AM WRONG!

 

With Bi-amp you have an amp for low and and amp for high.  Each amp with left and right out puts. 4 points of connection to speakers.

 

With tri-amp, you have an amp for low, an amp for mid, and an amp for high and there for 6 points of connection.

 

IS THIS CORRECT?