Axiom Home Page Forums General Discussion Technical Questions VP150

Hi all,

First post here, have a technical question.

My center channel speaker, a VP150 is no longer working. I know that the center channel output from the receiver is working (I connected the left speaker to the center channel output and I have sound). I checked the speaker wires between the VP150 and the center channel output using a multimeter, both + and - wires have about 10.5 ohms over a 11 foot length. I'm pretty certain the problem lies with the speaker, just not sure what to do next (aside from buying a new center channel speaker). Any suggestions? I miss my center channel....

Thanks,
Steve

Call Axiom.

Ken,

Thanks, but I got these speakers about 10 years ago (plus or minus a year), I'm guessing any warranty they had on them is over...

They'll still probably be able to help--after all, they know the speakers better than any of us! My guess, though, is either the crossover or a wire detached from the crossover (if you're lucky.)

Steve, measure the impedance of the positive and negative terminals on the VP-150, it should be 6ohms... Since you measured 10.5 ohms at the end of your speaker cable, this is high, even with your speaker wire in the circuit. The wire itself is only going to add maybe 1 ohm at the most to the over all circuit.

How old is your speaker, they come with a 5 year warranty..

For all the drivers to be dead, nos ound, you would have to have a major failure on the crossover or at the very least the input has broken off. I would pull the speaker wire plate off the back and take a close look at the crossover as it is attached to the back side of the plate; look for anything melted off, cracked etc.

I am willing to bet there are more than a few on this forum willing to sell you thier VP150v2 so they can upgrade to the VP180.

Ok, measured resistance across positive and negative terminals... open circuit. So obviously something is broken.

I pulled the speaker wire plate off the back, there's a board with electrical components and then 6 wires... one black, 2 blue, 2 white one red. There does not appear to be anything melted. I sniffed it and no whiff of burnt components on the board. Also, it does not appear any wires have separated from the board....

So what does that leave as a possiblity? I'm not sure what a 'crossover' is. I recognize a couple of white rectangular resistors, two cylindrical caps, another cap and then a couple of coil looking items, one open center and the other with metal plates running through the center... Is that last the crossover?

How do I test a crossover to see if its good?

I had the speakers a year or two before moving out of my old house back in 2004... so I'd say I bought them sometime in 2002 or 2003 timeframe which would make them 8 or 9 years old. Well out of the 5 year warranty period.

What you were looking at is the crossover.

Ken,

So, you are saying that the board/electrical components is the crossover?

If true, I see no evidence of burns/melting nor do I smell any hint of burned components... The wires attached to the board seem solid, no obvious cracks or breaks (at least from the board side).

Thoughts where to search next? I'm thinking of removing the speakers and checking continuity between the wires there, see if I can pinpoint a break somewhere. Seem like a logical next step?

Thanks.

buy one of these guys...

Ok.. the other option with the tools that you have, is...

Measure the value of the resistors, you can really only check to make sure that they are open, or short...

since your speaker is out of warranty, you can take the drivers out, and measure the resistance of each driver individually. One will have an open, they are most likely wired in a combination of series/parallel this is why you will measure each one individually to be able to determine exactly which driver is bad, so measure each speaker individually. If only one driver is bad, then you can simply order a replacement for single one that went bad.

if you really want... you can get one of these it has to be able to measure capacitors, not all flukes can. the setting between resistance and frequency is the capacitance setting. Your multi-meter might have one, maybe....

on a side/side note... I just noticed the link i gave you is for a multi meter, which is not manufactured by "Fluke" and does measure capacitance and cost's MUCH less than a fluke. I would say, buy the multimeter i gave you the link to, if your going to get another one.

If you need any more help feel free to ask.

Ok, I pulled all 5 speakers. The two out ones measured 6.0 ohms (left) and 5.4 ohms (right). The three 5.25" ones were ALL open circuit! So where can I get replacement ones? Does Axiom sell them (not sure if they are component sellers or finished products only)?

Or can I replace them with any 6ohm 5.25" speakers? I don't want junk but as you might have been able to tell, I'm no expert either.

Thanks again.

Axiom will sell them. They're relatively expensive (something like $60-70 each, I think?) but they'll work much better than third party replacements. I strongly recommend that you call Axiom before you proceed with any part replacements.

if you buy "matching" replacement speakers from another mfg.
you will lose most of the quality reproduction you should expect from your Axioms.
there are many other things than size and impedance that are much more important in a speaker design.

I think I'd go for the upgrade model myself before spending around $200 plus shipping for 3 repacement speakers. New VP150 v3 is $434, or $391 on the Auction site (buy it now price). Sure it'll cost twice as much, but you've warded off any potential expensive problems for another 5 years. (Did that make any sense?)

Not to mention a misdiagnosis.

Yes, if the replacement speakers are each 60-70 (180-210) then it's worth considering a new VP150. However, I also have a pair of M22's and QS8's of the same vintage as my current VP150. If I mix a new VP150 v3 with the other speakers, will there be any noticable difference?

I guess I'm asking what is different between the original VP150 and the newer v3 speaker? How much of an improvement has there been in the last 8-10 years?

Personally, I doubt that there would be "that much of" a noticable difference. If anything, I think there would be an overall improvement in sound quality. Then if and when you decide to replace the M22s (if that should ever happen), you would already be one step ahead with the newer VP150.

Ken,

Just curious, how could I misdiagnose? I removed all 5 speakers from the VP150. I tested the two high range speakers, one was 6.0 ohms and the other was 5.5 ohms, so they checked out as expected.

WIthout changing any settings on the DMM, I repeated the exact same testing procedure with the three 5.25" woofers. Presumably, all 3 should have read about 6 ohms, but all 3 were open circuit...

By open circuit, do you mean that it read Zero ohms?

If that's the case, then perhaps the real problem is the cross-over, feeding too much current to the speakers(???), causing them to go out. Just thinking out loud.

CatBrat,

Nope, zero ohm would be a short circuit.

This read off the scale (on my DMM a 1 is displayed in the left hand corner, not the right side as if it were 1 ohm). I slid from the 200 ohm range up to the 20M range, each one stayed the same so I'm certain it's reading open circuit on all 3.

Hawk, did you measure the resistors in the cross over? 3 components do not simultaneously fail like this. There is something else going on that made 3 speakers fail. I would tell you to check the resistors in the cross over network. Also, you can visually inspect the capacitors, look at the top and bottom of the capacitors, if any of them are bulging out a little bit, the capacitor has "blown". Again with the resistors, since you do not know what the "correct" reading is, look for a resistor that has shorted out, this is uncommon, when resistors fail they usually fail open. Also carefully inspect the cross over for any wiring "amiss". I would not spend money on replacement speakers until you determine what caused the 3 drivers to fail in the first place.



On a side note, if your going to buy a new speaker... Forget the 150... get a 180, it is WAY worth every penny.. And yes, the 180 sounds wonderful with 8 year old axiom's, you will have to trust me on that one.


keep us updated.

Also, if you want to post some detailed photos of the cross over/capacitors i will look at it for you if you want... and try to help where i can...

Speaker impedance varies with frequency of the input, so I wouldn't count on them measuring 6 ohms (or the total being 6 ohms). Nevertheless, Dakkon's right about it possibly being the crossover that nuked the drivers.

Thinking aloud, if the crossover nuked the drivers, wouldn't it nuke all 5 drivers? Just curious why the two tweeters measured 6.0 and 5.5 ohms (assuming that means they are still good) but it seems that the 5.25's are measuring open circuit?

Visually looking at the two electrolytic cap's (one is a 1.5 microfarad, the other is a 6.8 microfarad), there is nothing that appears distored (no bulging apparent) and neither smell burnt. There is another cap (106J 100V is marked on the side and a websearch identifies it as a polystyrene film cap). Again, no sign of melting or distortion with that one.

There are two white rectangular ceramic resistors (marked 7WR49 and 7W5R)... I'm familiar with the color stripes but not these... Do the markings indicate that both are 7 watt and one is a 49 ohm resistor, the other is a 5 ohm resistor??

If I measure them while they are still in the circuit, should I expect them to measure 'true' to the rating? I did measure last night, they definitely did not measure open (it was late, I didn't write down my findings).

What about those two coil looking items, one hollow (air core?) and one with what I believe are iron plates running through the middle... again, neither show any evidence of melting or any physical damage. How do I test them?

I will try to post pics later today, headed out for a few hours.

Thanks for your help and patience with a noob, I don't work with electronics frequently so I'm a bit rusty on the nomenclature.

Hi hawk,

Those coil-looking things are inductors.
Have you tried a simple test like using an AA battery, and connecting the leads to the input posts on each driver? If the driver is working, the cone will make a "click" and move either inwards or outwards, depending on the polarity you used to connect them.

This will not damage the drivers. If there is no movement of the cone, then the drivers are gone or fused.

Last time I checked, the drivers are from $48 to $52, including shipping.

Alan

"open circuit" means infinite resistance, like two wires not touching one another, where current does not pass.
"short circuit" means very low resistance, like 0 Ohms, where current flows freely.

I'm actually astounded there aren't any VP150v2s in the Auction Site! What color do you have?

Got a brand new AA battery, checked it was good (1.61vdc).

Connected the bat to each driver in turn, no movement or click (inward or outward) of the cone on any of them. Definitely three dead 5.25" drivers... If the crossover is to blame I'm still puzzled why the 3 5.25" drivers died while the tweeters appear to be alive.

I had assumed was that all 3 of these just went out all at once. Now that I think on it, I had noticed that the center channel didn't seem up to par for quite a while. I attributed it to the horrible room (big open great room, high ceiling, balcony, no real 'front' or 'back' echo-chamber) this is set up in and my increasing age. Perhaps the drivers have been dying one at a time and I've just been to oblivious to notice it in the forebrain until the last one died? What I'm saying is that maybe the fault is time and wear as causing the failures, not any issue with the crossover?

Can anyone tell me what the difference is in a v2 or a v3 speakers as compared to one about 8-9 years old? What improvements have been made that trigger a v2 and v3 namechange?

Regarding the colors, my speakers are black finish with black grille.

Thanks again for the help guys.

Steve, you've now confirmed that the voice coils in all three drivers are burned out, which is rather unusual, unless as you suggest now, maybe they failed over a period of time, rather than simultaneously. What amplification have you been using?

It wouldn't seem that the crossover would have anything to do with this. Even a total failure of the crossover would just have sent treble frequencies to the drivers which they wouldn't reproduce well, but this couldn't cause them to fail.

Considering the amount which replacing all three drivers would run, consider instead using a vertical M2 as the center, which some of our members have done with great satisfaction.

the main difference from what i can tell is a better crossover...

i think John is wrong you should get a vp-180...

if the drivers failed over time then it is possible that nothing is wrong with the crossover.. i do not know what the life expectancy of the drivers are, much of my system is comprised of 8 year old speakers, and all is well...

John,

My setup is pretty basic, I have a Harmon Kardon AVR 7200 driving the speakers. I do not have a separate amplifier. I use it primarily as a home theater sound system (optical input from the Panasonic DVD player... have yet to upgrade to Blue Ray). My wife uses it to play music from her iPod in addition to it's role as a home theater sound system.

In it's original configuration at my old house, I had it set up with two M22's as the right and left front speakers, the VP150 as the center channel, and the QS8's as the right and left rear speakers with the subwoofer a SVS PC12.

Due to the crappy room we are set up in at the new house, there's no place to put the two rear speakers, so I kept the front three plus subwoofer, hoping someday to set up a nice home theater in the basement with much more suitable acoustics than I currently have.

John,

Sorry I didn't answer your question. Per the owners manual, the AVR 7200 (in 7 channel surround mode) puts out 100 watts per channel into 8 ohms. Nothing about 5 channel surround mode which is what it would be configured for operating at. When I run movies, I like it loud. When my wife plays music, she also likes it loud, so I suppose that over time, the drivers on the center channel were worn out.

Hawk, have you thought about qs8 stands? i have used them in the past and they work quite well.

I personally found a single M2 to be a downgrade from a VP100. I'm not seeing why an M2 for center channel would be preferable over a VP150. Especially for male vocals, my VP150 is an improvement over the VP100. I can't imagine what a VP160 or VP180 would do.

Dakkon,

I had considered stands for the QS8's, but let me describe my nightmare room. The great room dimensions are about 17' x 17'. Ceiling is 'cathedral' height. There is a balcony over 1/3 the room, the rest of the room has cathedral height ceilings (echo chamber).

Only one wall in the room is a complete wall. Across from the complete wall is the dining room, so a good portion (but not all) of that wall is open to the dining room.

WIth the complete wall to your back, the left wall is two tall windows separated by a fireplace that extends into the room approx. 2 feet. Opposite the window wall is the front foyer with no wall in the great room.

Into this nightmare, I have an old school Mitsubishi 65" rear projection TV, big and bulky. It's situated in one corner of the room (where the dining room wall and the window wall meet) and is on a diagonal facing into the room. On top of the TV sits my M22's and the VP150. However, as the TV is on a diagonal, with the front speakers facing into the room on a diagonal, there's no real place to station the left rear and right rear speaker without intruding into a 'walkway' or seating area. There's really no truly defined 'rear' of the room.

While I really like the new house, the old one was a nice simple 16'x9' rectangle, single story flat ceiling room with minimal openings with a definite 'front' and 'rear' (none of this diagonal BS).

One of these days I'll partition an area of the basement and turn it into a man cave/home theater room with a defined front and rear but in the meantime I have to deal with the echo chamber.

They upgraded the drivers and crossovers, but I suspect the sound is still pretty close.

Hawk, it's all very puzzling, however, as soon as I read in your post that it's a "great room", with cathedral ceiling and that you and your wife "like it loud", I thought, oh-oh, he's had the VP-150 set to "Large" and he's clipped the H/K receiver and burned out the drivers.

Drivers don't "just wear out". They'll go on working for 20 to 30 years so long as they're not overdriven with an amplifier that's clipping or unless there's an original manufacturing defect. In the latter case, they'll fail very quickly. Crossovers are rarely defective, although a cold solder joint or cracked circuit board could be the problem, and that would be hard to see or detect.

Given the size of the room, and your listening tastes (loud), an M2 center (per JohnK) would be totally inadequate. I'd suggest at least a new VP150 or, the VP180.

As to audible differences in your VP150 and the v3 version, they'd be subtle and wouldn't be a problem in terms of tonal matching to your existing M22s.

Regards,
Alan

Alan, i would venture to say if he is driving the amp into the clipping region with his current vp-150, the same will happen with a new 150 with the same result... 3 blown drivers... The best most realistic solution is a vp-180. All joking aside, the 180 will play much louder with less power required. The HK amps can handle a 4ohm load quite well from what i have read. To pressurize a huge room of the size you are talking about hawk, the 150/22's seem quite small.. you might be able to just upgrade the center and leave the 22's alone. The number one thing that kills drivers is "bad power" or an amp being driven beyond is capabilities.

Hawk, could you venture to guess what the total volume of the great room+ associated adjacent rooms would be, a total volume number would help determine if what you have is realistic or not, a 150 with all of it's drivers working may in fact be just fine.

Since a speaker is basically a coil of wire, it is pretty hard to make a piece of wire fail. As Alan said " drivers don't wear out". In the 70's/80's when woofers were were paper and foam, the foam/glue would deteriorate over time. However, with the new materials used today this is not the problem it was 30 to 40 years ago...

Hi dakkon,

Yes, I'd basically agree with you. I too thought his system is small for such a large space, and while the H/Ks drive 4-ohm loads just fine, I'm not certain the increased sensitivity of a VP180 would be sufficient to reach the loudness levels he prefers.

"Loud" covers quite a range of personal taste; Axiom colleagues of mine sometimes listen at levels that are very very loud, far higher than I'm comfortable with. If that's the case with Hawk, I'd prefer to see him use an outboard power amplifier for the center channel, something in the range of 200 watts or more. He could use the H/k's internal amps for the front left and right and surround channels.

Alan

Alan, I was going to bring up the idea of an outboard amp, i actually had it typed up and ready to go in my last reply.. However, i decided not to bring that idea up as i wanted to reduce "my spending of his money" if you will.


Hawk, when i moved to my current house i had to buy larger outboard amp's because my old one was being driven into the clipping region due to the increase room size, i am in a someone similar situation as yourself, moving to a house with MUCH more airspace. (the amp has led's that would notify the user if the amp was being driven into the clipping region). The house i am in now has a family room that is open to the kitchen, entry way, and formal dining room. So, there is a LOT of air space. I have M-60's and a vp-180. My previous amp was a Marantz mm9000 rated for 135W per channel. My new amps are rated for 250W per channel at 8ohm and 500w at 4ohms. With clean power you can push speakers much farther without damage. I decided to buy more power than i would ever need to prevent damage to the speakers.

But this, and the posting of photos, is the Mission Statement here...(?)

Alan/dakkon,

Thanks for the responses. However I'm not sure what you meant by 'clipping'... I am guessing that you mean i have the volume turned up so high that the amplifier in the receiver is overpowering the ability of the drivers to handle... Is that correct?? Is there a way for me to know whether I am in that mode? Would the receiver 'cut out' possibly, as though it was overheating and tripping a thermal breaker? Or would there be some other indicator??

Reason I say that is because my wife did say (now that I think about it) that she thought there was a problem with the receiver and that 'it just stopped working' a week or two ago... When i turned it on briefly i noted that it was working so i just dismissed it as a case of operator error, a one time fluke... Possibly she was jamming and she burned them out and I just didn't do enought testing?

Just noodling the room and adjacent rooms. Great room is 17x17 feet. Assuming the main floor is say 10 foot that would be a volume of 2890 cubic feet. Guesstimate half again for the cathedral ceiling so call it about 4500 cubic feet. The adjacent dining room is 12x14x10... Call it another 1700 cubic feet. The foyer/entry/stairs abutting the great room would be appx 15x7x18 for 1890 cubic feet. So a reasonable guesstimate would be about 8100 cubic feet (give or take a bit).... Knowing that, what are your thoughts??

Regarding loud... My ears haven't bled so it couldn't be loud....

Hey Hawk,

Clipping as actually when the receiver is asked to produce more power than it can cleanly produce. In the case of clipping, the root cause is the receiver, not a weakness in the speaker. Specced to handle 400 watts, the VP150 can probably actually handle much more power than your receiver is capable of 'cleanly' producing.

If you turn up the volume to the point where the speaker needs to draw more power than the receiver can produce, then the receiver tries to oblige but the effect is that the top and bottom of the frequency wave gets "clipped" off (thus the term "clipping") because it's hitting it's limits at that point in the sine wave. The result is a squared off wave and this type of distortion gets increasingly audible the more you push it and eventually becomes damaging to speakers.

A regular sound wave.

.
A clipped sound wave.


Most modern receivers will shut themselves down before too much damage occurs but there is always this inherent danger if you push volume levels too high.

Murph, thanks for explaining the clipping definition.

Most of the time in a situation like this, the speakers can actually handle much more power than the source is capable of providing, so the source (amp) is actually the cause of the problem, blown drivers is just the result.


Ask your wife if she remembers how high she had the volume turned up when the receiver "shut down", if she had the volume turned up almost to max, the receiver could have gone into thermal shutdown mode. This is to prevent any damage to the receiver, not to your speakers. Part of an amplifiers ability to produce power is it's ability to dissipate heat. For example, if you have a forced cooling setup, a given amplifier can produce more power safely than a an amp with only passive cooling (similar to over clocking a computer). Keeping the transistors cool is the number 1 goal in this instance. The way that power amps are able to produce much more power than receivers is that they have many more transistors, as well as much larger power supply and capacitor sections... But the point being, more transistors= less work/heat generated per transistor.. If you look at the large amps produced by many of the high end companies, they will have HUGE aluminum heat sinks that their transistors are bolted to... to dissipate as much heat as efficiently as possible.

So, where is your receiver located? Does it have lots of open space around it that would provide a natural efficient radiant cooling? On my AV rack, each amp has 1' of clearance above it to ensure that there is enough room for unobstructed airflow.


Room size, I would tell you to wait for Alan to give his opinion, or call axiom and ask Brent/JC. Any of those 3 guys will give you a realistic recommendation without trying to over sell you on your true needs. However, in the mean time. Try to quantify "loud" do you mean the same level as a rock concert? Movie theater? opera? Jet engine from 3' away? Try to come up with a real world relation that you can make, to give them an accurate level that you and your wife are trying to achieve, this will help them give you a good recommendation. The last thing you want to do is spend good money after bad, and not get the results you are truly looking for.


I think that in a way you have opened a can of worms my friend. I have a feeling the recommendation that you will receive will involve buying larger speakers.

Murph, thanks for the info. You said that most modern receivers will shut down before too much damage occurs, I wonder if that's what my wife described. I will ask when I see her tonight. Maybe it's happened more than once, I know I've never experienceda case where it shutdown. I wonder if the HK AVR7200 is modern enough to shutdown it detects clipping.

Quote: "Regarding loud... My ears haven't bled so it couldn't be loud...."

wow! that must mean you like your movies/music very loud.
if that is so, then the minimum you should buy is M80 speakers and around 300 Watts per channel or more into 4 Ohms.

if you want to protect your equipment, try to find amps that have led peak indicators; if you have difficulty finding those, have a look at proamps, most have those peak indicators.
if those led's ever light up, then you lower the volume a little bit and you'll be ok; and the equipment too.

a good subwoofer would also be a good addition; your front speakers will work less hard.

others here will surely give you better tips than me.

Dakkon,

Yes I will get more info tonight regarding what level she was running.

The receiver is on the top shelf of the 3 foot tall shelving unit. Normally there is nothing stacked on top but recently there have been DVD cases left on top of the receiver which would block the top vents. The Harmon Kardon AVR 7200 has passive cooling and has large aluminum heat sinks on the left and right side of the chassis. There is nothing blocking the left/right side vents.

So if clipping is the issue, one obvious answer is to reduce the max volume used. Another is to add a separate amp to drive the center channel (not sure why I would only drive center channel, is that to "spread the work out" so the separate amp is not overloaded into clipping mode)? Or I could upgrade to the VP180 (but then what of the M22's, are they at risk too?). What about my subwoofer (SVS cylindrical powered subwoofer 12") is that in danger or since it is already powered with its own amp, it should be safe?

Regarding loudness I would say as loud as a movie theater when playing movies. I don't think she typically goes much louder but who knows when I'm not home...

Hawk, make sure you check the settings, too. It's not just "how loud" but "how loud at what frequencies" that matters.

Murph or somebody else smart already alluded to running the speakers as "large" which you probably should NOT do. That is, have the crossover in the amp send all signals below 80Hz (or whatever you choose) from all channels to the subwoofer. If your receiver only has to push signals above that frequency AND your speakers only have to produce signals above that frequency, everybody will be a lot happier. So, noodle around in the settings on your receiver some.

i think that all receivers have 1 power supply, that power supply is providing power to all channels of amplification, all processors for the signals ect.

the more powerful outboard amp is so that you can get the same volume without driving the amp into the clipping region on the affected channel.

the center channel is where 70% of the audio information in a movie comes from, hence the reason i was recommending a 180 to replace the current 150, and why Alan recommended an outboard amp. if you had blown the pair of m22's the recommendation would have been different.. you were trying to get the 150 to do a job it is not large enough for i think... You just need a larger speaker with more drivers.. The SVS, it depends on if you are driving it past the amplifiers limits.

This whole conversation can be boiled down to staying with in "design specifications"

I would say call axiom if you haven't already, and tell them the situation and see what they have to say. They do this stuff all day every day, and have experience with rooms such as yours i'm sure.

So, now I know "the rest of the story"... My wife had a birthday party for her girlfriend and she had all the girls over and were playing the stereo "real loud" for "a while". I asked her to define those loose terms. She said they had it going for over an hour and had it loud enough so they could 'hear the music outside' which is where they were hanging out... mind you that was the other side of the house. So, I suspect the clipping theory is the most likely one.

Knowing that, I am now concerned that the M22's could have been damaged at this gala event... Any way to test them to determine if any damage has occurred?. Ditto on the subwoofer.

Now it's a case of what option to choose.... Replace the blown drivers, get a new VP180 to replace the VP150, get a new receiver able to withstand her onslaughts, or a new amp to drive the center channel.

Hawk, lots of speakers get blown at parties when users "crank it up" in the spirit of the occasion, especially when drinks are flowing.

Try playing a CD, one with cymbals, vocals and good bass in stereo, turn the balance control all the way to the left, and listen to each driver of the left M22, with your ear fairly close (use a moderate volume level) while covering the other two drivers to make sure you are isolating each driver. Usually, the driver will work fine or it won't issue sound at all. If the voice coil is warped from heat or overdriving, you might hear a distorted scraping sound. You can also use the battery check I described to check the woofer/mids. Repeat the test for the right M22, turning the balance control all the way to the right.

By the way, your H/K has good protection circuitry, but that's used to protect the output stage of the internal amplifier, not to shield your speakers from clipping damage.

I doubt the subwoofer is damaged, but you can try gently pushing in the cone of the driver with your hand (with the subwoofer switched off)and fingers applying equal pressure. You should not hear anything if the subwoofer is undamaged.

If you do hear a scraping sound, then the voice coil has become warped or fused from overheating/clipping and is scraping against the magnet assembly as you press the cone in and out.

If you're really planning on playing stuff super-loud, then you need an outboard amplifier for at least the front three channels, and preferably larger floor-standing speakers like the M60s or M80s. Either that, or keep the M22s, get an outboard amp and a new or repaired center, and control the maximum volume level. The M22s are great little speakers and will play remarkably loud and clean when supplied with clean unclipped power in an average living room or slightly larger space, but I really think your much larger room demands bigger more capable speakers and a big amp.

Regards,
Alan

Steve, reading the details that you now have of this horror story, it seems clear that although you can replace damaged drivers or an entire speaker, you can't replace your and your wife's lost hearing. Since obviously she doesn't do this, allow me the liberty of yelling at you: "turn the damn thing down!" Seriously, you should use a SPL meter to monitor the levels that you use. "I like it loud" isn't(or at least shouldn't be)an acceptable standard for determining safe sound settings.

The amplifier in your 7200 is quite powerful and the 100 watt rating is a typically conservative one from HK. A quick search found these lab measurement numbers for the essentially identical amplifier in the 7300. You don't need a new receiver or, except for replacing the damaged items, new speakers. Yes, it's unusual that only the mid-woofers in the VP150 would be affected, since the far more delicate tweeter voice coils typically are damaged first. Also it seems that the M22s would have been damaged at that time.

I'll again mention the possibility of using an M2 center, which can do an excellent job at typical listening distances and safe sound levels. See for example Dan's M2 vs VP150 report .

John, the last bit of information that i just realized that we do not have is, what audio processing mode the receiver was set to. If it was dolby pro logic, or any of the dolby settings, the majority of the "music" would have been coming from the center not the M22's. If the receiver was set to stereo/enhanced stereo, or 6 channel stereo, then the L/R/ all channels would have received the same signal. Without this information we can not make the assumption that the M22's made it though, maybe they weren't receiving much of a signal during said incident.


Also, An SLP meter will not work when a wife knows where the "volume knob" is... Hawk, there should be a "volume limit" option in the settings of the receiver, this will limit the max output, so if the wife wants to "turn it up" you can control how much she gets.

The next question would be. How often does your wife has these "parties"? and do you expect her to continue having these "parties". if either of those answers is often/yes, then i say get bigger speakers as Alan said... I would say buy bigger speakers, run them off of the receiver that you already own, see if they are loud enough for you and the wife. It is possible that with larger speakers you will get more output for your given amount of power, so you may not need more power (aka external amp), as John said your receiver is rated for 100W.

Yet another option would be, if your receiver has 2 zones buy some Algonquins to install outside where the wife had/has her party/parties, this way she can play those speakers, rather than the "inside" speakers. You will have to ensure that she understands why and is willing to do this though. Under this scenario, i would be willing to agree with Johns recommendation.



P.S. a quick look at that painfully long instruction manual says your receiver does have 2 zones (john, i feel for you reading through those things!!), with assignable amplifier channels. So the Algonquin idea would work for you.

Alex, I didn't follow the comment re the center speaker getting the majority of the music. I use DPLII or similar at all times with music. The mains keep the in-phase content and a portion of it which is about equal in level in the two channels is also sent to the center speaker for a more anchored center image. The out-of-phase material which represents surround ambience is extracted from the main channels and sent to the surrounds. The center speaker carries far less than a majority of the total music content.

I though under DPL processing the center carries the majority of the information, with the L/R as fill? That is what i was basing my comment off of.


I could be wrong. Under those conditions, it would explain why only the center had issues though.

I like the volume limiting on the receiver idea. My Pioneer Elite has this option. I use it just in-case something happens to the remote that causes the volume to constantly increase.

Same here.

Hi all, and JohnK,

Like you, John, I've always disagreed with the notion that the center gets most of the energy. I don't know where this myth started. With movies, the center channel carries dialogue and on-screen sound effects, which of course can be high-energy in blockbuster type movies. With music playback in DD 5.1 ( and DPLII and its variants), the center carries vocals, and some part of an orchestra or band that's centrally located, or solo instruments. But with both movies and music, a great deal of the orchestra/band is mixed to the front left and right and even some to the surrounds.

Lots of good suggestions, including using zone 2 for a a pair of outdoor speakers on the side of Hawk's house where the partying occurs.

I, too, have shouted to "turn the damn thing down" John, but I don't think you allow for the frailties of people who love music when they're stoned or boozing; look at the absurd volume levels used in dance clubs and concerts where everyone is high.

Regards,
Alan

Get a portable sound dock for your wife that she can lug outside with her MP3 player, CD's. Very easy for her to setup, won't need to fiddle your main system and it will provide her music at her finger tips. A sound dock would be able to provide sufficient loudness levels (avoid Bose though, which suffers from noticeable compression at higher levels) at her parties since she can setup directly were she is entertaining and can move it around if the guests go to a different area or to a room inside.

It will be her own little toy and I bet she will love it.

Good call - or look into a distributed audio setup such as Sonos, Squeezebox, Airport Express etc... to get music wherever you want it easily.

Does anyone here presently use Sonos or Squeezebox?
I've read alot of good things about Sonos but was leaning towards the Squeezebox idea since i may be considering a shared video option for our home offices as well.

Here is a sound dock that would work well in your situation. Give it to her for Christmas. You would be able to find it even cheaper at stores in the US.

http://www.futureshop.ca/en-CA/product/h...c166237dbeben02

Hi Chess, I have a Sonos system that I have been using for the past ~4 years. Let me know if I can help answer any questions.

Cheers,

There's no way that these things are going to even come close to sounding like the Axiom speakers. Seems more like offering her a slap in the face to me.

While it is an "easy" solution, it costs 2/3 what a pair of Algonquin 's would. However, if the spouse would not want to use the second zone speakers, or forget to use it, then it might be a better idea to go with the portable music idea.

I had an HK 7200 for a while, driving M80's. This is one hell of a receiver and not like the playschool receivers being marketed now. That was back when HK made simple and robust amps for what WAS excellent gear (not like the crap they pedal now). There's no way in hell it was ever clipping.

Just get your wife a set of M80's. No need to carry an Ipod dock or anything like that around with M80's in the house.

Mike, that wasn't the one that caught fire, right?

Wasn't that a Marantz?

As many here know, my Squeezebox has been, for years, the absolute favorite gadget in my house. I use it daily almost without fail. Internet radio in the morning for local news and such and then it's primary purpose to access my music collection during the evenings and weekends. I was feeling the need to upgrade my older 'Line of sight controlled' unit for a while there but since the remote control apps for iPods and iPads came out I no longer have that urge. It remains my favorite gadget ever.

It's also fun to hand the iPad control over to guests and let them have at my music collection. At nearly 7000 songs, they sometimes dig up stuff I have forgotten that I even had.

FYI, replacement drivers are $46USD each, so at this point in time I believe that I will take the two step approach:

1) Replace the 3 drivers in the VP150
2) Use the feature on the HK 7200 which limits the volume.

Only question is, how do I know what to set the upper limit at? Is there some physical way to know just by listening? Or would I need an oscope?

BTW, I did not have the receiver set to "Loud", it was on "Soft"

i set mine to 28... It's an arbitrary setting, and the number scale on my processor is more than likely completely different than your receiver... For a reference, "normal" TV viewing is 12 on my processor. i think it is a 0-100 scale.

Having the volume limit set on the receiver is always a good idea no matter what. This will prevent your speakers from any damage in the future from your wife or guests, but the reason why your wife turned up the volume so loud was to get sound across the house and even OUTSIDE mind you. That is the big problem you have to solve. This is an unreasonable and ridiculous application to begin with and now adding a volume limiter to get reasonable volumes of music through multiple rooms and outside from a distant room won't work very well IMO.

I can recall once when I did not have the volume limit set and my remote control went batshit and pegged the volume on my 7200. My ears rang for quite a spell after I changed my shorts.

No Tom, and no Chess.... None of my failed receivers ever caught fire....smartasses. They just decided to not work. I did however have a stinking .50 cent fuse blow on the 7200. Cost me $100 service charge to fix..

BlueJays1,

I agree with you, it's not reasonable. However, stuff like this does happen from time to time (not with regularity or it probably would have destroyed the drivers earlier).

Besides, I purchased the system and gave it to her for her birthday, so technically it's her's to do with as she wishes.

However, after I explained last night that blasting the volume so she could hear outside the house is what most likely caused the failure, she does understand. To be certain it does not recurr, I will activate the volume limiter

The volume scale on the HK 7200 goes from maybe -60 (lowest) up to maybe +5 (highest) in the display, not sure why it starts at a negative number. Typically I would set it at -15 for great audio movies like Master and Commander or Star Trek, hopefully that keeps it out of the clipping range.

Is there a way to test it? Would I need to hook up an oscope to view the waveform coming out in order to determine the exact clipping point? Also, will clipping vary with ambient room temperature and the temperature of the equipment (hotter making clipping occur lower on the volume scale)?

you could very well check it on a scope, it will always show you clipping even if it's happening by only a small amount.

i don't know what other piece of equipment (that gives good results) you could get for that.

others will tell you more. :-)

There really isn't another piece of test equipment that will tell you if you are driving the amp to hard. Yes clipping will vary with the ambient temperature, like i said earlier, the whole point is to keep the transistors cool.. search the online pdf version of your receiver, there may be a "clipping" indicator. On the amp i have in the bedroom, each channel has a clipping LED indicator, that will light up if a channel is being driven into the clipping region, i don't know if this is an option that receivers have or not.

When i would tell you to set the max volume maybe 5-10% higher than your "reference" level, which for you would be your movie level. See how everything works at the max setting, and go from there, But keep in mind, if your wife has another party, and one of her friends does turn it up, they may reach the max setting, and the system may be left there for an extended period of time, so keep this in mind.

Unfortunately, this is one of those topics that is a grey area, there is no quantitative answer that we can provide you. One option would be to call the manufacture, and talk to a technician, they will have MUCH more information on what a safe level for extended use would be.

Steve, small amounts of clipping are harmless and generally inaudible. Yes, other than hearing the distorted sound if it was heavy and prolonged, examining the waveform on an oscilloscope is the way to detect flattening of the wave tops.

As a practical matter, as Mike pointed out above, you're not going to have significant clipping taking place with an amplifier as powerful as the one in the 7200 if the sound level isn't dangerously high. Again, using an SPL meter, such as the digital model from RadioShack, is a good way to monitor actual sound levels which are experienced at the listening position.

Hawk also if you are a user of either iPad or iPhone there is a free SPL app that will be sufficient for monitoring the pressure levels your system is putting out, for calibration purposes I'd recommend the Radio Shack meter but for monitoring loudness levels the i apps will be perfectly fine.

Hawk, your H/K volume indicatorn (like my H/K and many other receivers) is calibrated in decibels (dB). For your purposes, you can assume that "0 dB" on the H/K readout is at or approaching the maximum output of the amplifier, so avoida that level and keep your playback levels to a max of -10 dB. My H/K's settings are very similar to yours. Loud movie playback is a -15 db. Music in DD 5.1 or DPLII is around =20 to -25 dB. The latter will vary depending on how "hot" the CD or source recorded level is, which also affects clipping.

There are no accessory clipping indicators, and the complexity of the music will also affect clipping, so it's impossible to determine an exact clipping point. Just stay away from the 0 dB point on the H/K and you'll be fine.

Regards,
Alan

There is some info about accessory peak reading meters here:
http://forum.qscaudio.com/forum/viewtopi...24931420dd51d3c

Too costly for my use, i did not buy one; but the info could be useful for others.

Hawk, if you want to understand the decibel, here's a link to an article of mine in the Axiom articles archive:

http://www.axiomaudio.com/understandingdb.html

Just remember, as the negative numbers get smaller, the power output of your H/K amplifier increases--gets louder. Over 0 dB, the number turn positive and puts you in the region of distortion and clipping. The relationship of dB and loudness levels on the H/K is accurate, so if you increase your volume level from -23 dB to -20 dB, an increase of 3 dB, the music will get "somewhat louder", but will require the H/K amp to produce twice as much power in watts for that slight increase in listening volume. To make music subjectively "twice as loud" will require ten times as much power from the amp.

Alan

There are not only spouses to worry about, but if you own any pets. I paused a movie I was watching and went to use the the restroom one time. My cat at the same time jumped up on and couch and laid down on top of the remote and the volume slowly went up to max. I ran out there (I think that I zipped up) and quickly lowered the volume, so it was only for a couple of seconds, but that is an easy way to damage some drivers. At that point I set the volume limiter to -13dB, which is way too loud for me.

Nick, my dog has done this 3 times!!, accept he always hits the power button so everything becomes quite.....

My dog keeps grabbing the remote and TiVoing Animal Planet! Unless he recognizes some of the episodes as re-runs or there's not a lot of space on the TiVo.

I get so mad at him, but then remember that he always slo-mos the Vicky's Secrets ads, so it's hard to hold a grudge.

Vicky's Secrets?
Is that like Victoria's Secrets but for rednecks and all the model's wear extra large stretch pants or seriously undersized gym pants and pose with rifles while spread across the McDonalds counter at Walmart?

Oh Sorry, that is the Vicky Joe's Secrets catalog. Shake and Bake Brotha!!!!