Will my receiver be adequate for my new Klipsch speakers? Can a bad amp break speakers?

[djk]

From an old post of mine:

Drivers fail for two reasons:

Excess average power

Mechanical damage

Clipping will not hurt anything if it does not cause the above problems.

After larger amplifiers (above 50W) became common, problems with high frequency units self-destructing became a problem.

A tweeter like the EV T35/Klipsch K77 could handle 5W continuous, 50W for 10mS peaks, so normal program material wasn't the problem.

The tweeters were dying from mechanical failure. The voice-coil was wound with aluminum wire that ran out to the terminals on the frame (self-termination). Shallow slopes in typical crossovers (6dB) combined with higher drive levels produced failures. Copper wire was tried instad of aluminum (aluminum work-hardens in a very short time).

Still, the failures continued.

Klipsch switched to the 18dB crossovers in the very early 70s. This helped with the excursion failures.

Now, 100W+ amplifiers became common.

Klipsch went to cathode-to-cathode connected zener diodes. These clipped off the peaks that were mechanically destroying the tweeters. Things went well for about ten years.

In the early 80s it was time to try and get rid of the expensive band-aid (the zener diodes). EV changed the lead-out wire from the self-terminated copper voice-coil wire to a flat BeCu wire like used on expensive JBL and Altec type compression drivers. A new network was designed with an elliptical filter with 50dB of attenuation only a half-octave away from the crossover point. A fast- acting instrumentation fuse was added.

Problem solved?

The new version of the tweeter used a UV cure adhesive vs the old thermo-set adhesive. After the fuses blew from modern program material (about the same time as the introduction of the CD), they got replaced with fast-blow types (which offered reduced protection). The special instrumentation types were very expensive, and very hard to find.

The new UV cure adhesive got soft, bubbled, and failed quite easily.

A PolySwitch was tried. Too slow.

The old thermo-set adhesive came back.

The combination of the super-steep crossover, the flat BeCu lead-out wire, and the PolySwitch seemed to work (with the old adhesive).

The zener diodes were retired for mainly two reasons: cost, and limited dynamic range. The AA networks used a pair of 5.1V 10W zeners. These only allowed about 2W RMS through before they started clipping off the peaks (a 4W peak square-wave) .

With the advent of digital program material, 2W of undistorted program material no longer seemed adequate (about 97dB at 10 foot). The zeners limited the maximum distorted output to about 100dB at 10 foot.

Removal of the zeners allowed exploitation of the 50W/10mS rating of the tweeter, about 14dB more output capability (referenced to the 2W RMS zener clamp).

What did EV do for products sold under their brand?

The STR tweeter protector (relay based) was developed for this use. Later it was modified by adding a lightbulb in parallel with the relay contacts.

I hope this give a little insight into what is needed for tweeter protection, and how we got to where we are.

Vifa, Dynaudio, and others offer a choice between self-terminated tweeter lead-outs and a braided (or tinsel) type lead-out.

The difference in cost for the braided type is worth it in my book. Most manufacturers of lower-priced product do not spend the money for this, or better crossovers either (although I am seeing lighbulbs and/or PolySwitches in some inexpensive product).

Crossovers and tweeters must be designed to avoid mechanical damage in normal use (correct slope, frequency, and lead-out wire for the intended use).

Long-term thermal protection is worthwhile. Some sort of switch device (relay, PolySwitch, fuse) in conjuction with a lightbulb seems to be the most cost-effective. Due to the long time constant of lightbulbs, most use does not seem to demand the switch (which shorts out the lightbulb in normal use).

Suggested current levels:

For 1" coils (tweeters), about 1A. The 561 or 211-2 automotive lamp has worked well in this application.

For 1-3/4" coils (1" compression drivers), about 2A. The 1156 type automotive lamp has worked well in this application.

For 3" (kapton) to 4" (nomex) coils (2" throat 16 ohm compression drivers), about 2A. I have found a 1.5A AGC (or 3AG) type fast-blow fuse will pass 400W of program material in normal use, and blow almost instantly if bad feedback is encountered. A pair of 1156 automotive lamps wired in series with each other, and then wired in parallel with the fuse will allow the show to go on when the fuse blows, and still offer some protection. If the fuse blows in the course of normal use, you need additional HF drivers, horns, and amplifiers.

[babadono]

" At its maximum forward or backward excursion it is sent this clipped signal, what is it going to do? It is going to try to stop and stay at this amount of excursion as long as the clipped wave lasts. When the cone is not moving no sound is being made. Also the clipped waveform is DC voltage which generally speakers do not like."

what is incorrect about this?

[001]

I worked at the Audio Room in Cedar Rapids Iowa off-and-on from 1974 through 1988.

We became a Klipsch dealer in 1978, and quickly became the largest single Klipsch dealer in the USA.

Prior to this we were the largest JBL dealer in the Midwest, including Chicago, St Louis, KC, Twin Cities, etc.

I wore many hats there over time, including sales manager and service manager.

One day the owner called me on the carpet and complained: 'all you ever sell is Yamaha, Ortofon, and Klipsch'. I said: 'isn't it great, we have no competition on those brands locally and can make a decent profit on them'. Crown, Sony, JBL, etc. set up dealers all around us and eventually all their sales went flat. National sales managers are all brain-dead to anything beyond the next quarter's sales. We had a total of seven sales people, and in one four month period I sold more than all the other salesmen combined.

It's really hard to hurt a Klipsch speaker, but it can be done.

small world. i'm in cedar rapids, do you still live here? i was a frequent customer at the audio room back in the late 80's & through the 90's, heck i still go in there from time to time to audition the new stuff that comes out. i used to have a friend that worked there a few years after you stopped. great place to shop & audition. thats where i heard my first k-horns.

[djk]

"i'm in cedar rapids, do you still live here?"

Yes, I work at Rockwell Collins currently.

"what is incorrect about this?"

It's so irrational I don't know where to start.

http://forum.qscservice.com/viewtopic.php?f=29&t=2736

http://pdf.ebooks6.com/RaneNote-128-POWER-AMPLIFIER-CLIPPING-AND-ITS-EFFECTS-ON-pdf-e18227.html

http://forum.speakerplans.com/does-a-clipping-amp-damage-speakers_topic66947_page4.html

http://forum.speakerplans.com/how-much-power_topic43488_page2.html

Edited February 21, 2014 by djk

[derrickdj1]

It is not just the front speakers that get LFE, any speaker set to Large. The OP does not have a sub.

[garyrc]

Thanks, djk, for all the info.

I'm still not clear on how much and what kind of protection the AK4 Klipschorn with the K77F tweeter has. I know it has a steep crossover slope, but I think it does not have the BeCU wire. I tend to play movies at Reference Level in our Klipschorn equipped Home Theater, which would have occasional peaks of 105 dB (not counting the subwoofer which is allowed louder peaks of approx 115 dB) at 16 feet (as adjusted by Audyssey). Should I worry?

Edited February 21, 2014 by Garyrc

[ryanm84]

I worked at the Audio Room in Cedar Rapids Iowa off-and-on from 1974 through 1988.

We became a Klipsch dealer in 1978, and quickly became the largest single Klipsch dealer in the USA.

Prior to this we were the largest JBL dealer in the Midwest, including Chicago, St Louis, KC, Twin Cities, etc.

I wore many hats there over time, including sales manager and service manager.

One day the owner called me on the carpet and complained: 'all you ever sell is Yamaha, Ortofon, and Klipsch'. I said: 'isn't it great, we have no competition on those brands locally and can make a decent profit on them'. Crown, Sony, JBL, etc. set up dealers all around us and eventually all their sales went flat. National sales managers are all brain-dead to anything beyond the next quarter's sales. We had a total of seven sales people, and in one four month period I sold more than all the other salesmen combined.

It's really hard to hurt a Klipsch speaker, but it can be done.

I bought my KG4 brand new from the audio room in Dubuque, iowa in 1990. The stickers on the shipping box say they were shipped to the audio room in Cedar Rapids originally. Small world. I still have my handwritten receipt for the purchase too.

Also have family and friends at Rockwell too.

Edited February 21, 2014 by ryanm84

[billybob]

According to OP single post he has a sub.

OP, the receiver is made to hookup to speakers. Klipsch speakers even better. All this worry over things that won't happen. If you make a mistake, there are speaker parts available.

How is it sounding?

Thanks

[ppoint]

Thanks everyone. Interesting discussion! I've had a very positive experience for my first time posting here.

OP, the receiver is made to hookup to speakers. Klipsch speakers even better. All this worry over things that won't happen. If you make a mistake, there are speaker parts available.

How is it sounding?

Thanks. It seems wise to me. What can I say? I'm a worry-ier.

I'll hook it up the new speakers to my existing equipment. If it's insufficient, I have my heart set on a new or refurbished Marantz unit.

At any rate, I'll let you know how it goes!

[billybob]

Fair enough!

Meanwhile, if you haven't read, please read your thread. Good folk here!

[001]

"i'm in cedar rapids, do you still live here?"

Yes, I work at Rockwell Collins currently.

cool, my dad retired from rockwell, & i know a few people that work there too. would love to chat with you sometime about upgrade options to my k-horns. thought i was the only iowa member here.

[babadono]

Next time you get sound out of a speaker cone that is not moving please announce it to the whole world.

JEESH!

[djk]

+1

[ppoint]

I picked up the Fortes this weekend and I'm happy to report that the little Yamaha YMC-500 seems to be doing alright.

Also, I have to say something about the Fortes: wow!!!! Awesome! I'm absolutely loving listening to stuff with these. Absolutely wonderful. I'm very happy.

[billybob]

Superb, and thanks! Next time, ask forum for something hard.

Do stick around though and let know how the Yamaha handles the KG1.5 added for the rears.

A couple or more here were thinking you might hook up the sub, for a hoot.

Have an older Yamaha AVR. Plenty of power. Can you hear any bass from the fortes'?

Edited February 24, 2014 by billybob