System employs custom 4-piece distributed sub-woofer array + custom 2-way stand mount main speakers.
Main Speakers:
Active high-pass crossed 2nd order @ 80 Hz
Dynaudio Esotec 17cm 17WLQ 8 Ohm, mid bass above tweeter
Dynaudio Esotec D28 dome
Passive LP and HP, 1st order @ 2.2kHz (about 4 dB tweeter pad w/ inverse-heat-sensing Deuland series resistor)
Amp: Ncore NC400 mono blocks 200W @ 8 Ohms 1/3rd duty cycle. Unless I'm mistaken (easily the case) in this application the amp power peak about equals the speaker's power handling.
On peaks at admittedly high SPL, with significant mid bass, the main speakers (not subs) produce loud, startling, obnoxious "click" similar to hammer against anvil. Is the described sound more likely amplifier distortion, the speaker being over powered, or combination thereof? If the speaker, more likely mid bass, tweeter, or both?
The symptom occurs regardless of amp, speaker, or input signal.
Thanks!
Main Speakers:
Active high-pass crossed 2nd order @ 80 Hz
Dynaudio Esotec 17cm 17WLQ 8 Ohm, mid bass above tweeter
Dynaudio Esotec D28 dome
Passive LP and HP, 1st order @ 2.2kHz (about 4 dB tweeter pad w/ inverse-heat-sensing Deuland series resistor)
Amp: Ncore NC400 mono blocks 200W @ 8 Ohms 1/3rd duty cycle. Unless I'm mistaken (easily the case) in this application the amp power peak about equals the speaker's power handling.
On peaks at admittedly high SPL, with significant mid bass, the main speakers (not subs) produce loud, startling, obnoxious "click" similar to hammer against anvil. Is the described sound more likely amplifier distortion, the speaker being over powered, or combination thereof? If the speaker, more likely mid bass, tweeter, or both?
The symptom occurs regardless of amp, speaker, or input signal.
Thanks!
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Yep this leads me to believe that you've damaged a speaker somewhere, either that or you need to cut back on the power.
A driver could be damaged, whenever I hear a speaker making a click its usually the voice coil apex hitting something, cut back on the power and consider yourself lucky.
If it continues to do it then try isolating it on either the left or right speaker, if its just one speaker doing it then you are narrowing down your search to the culprit and you could get away with just replacing one driver, a relativley easy and least expensive fix.
I'm surprised you're driving speakers at their rated maximum and expecting them to just take it like they were built for it when they are clearly not, then complaining when they click and destroy themselves!>!??
Mid-bass. Or in ye olden terms, "a woofer", and yes you never run a speaker at its rated maximum, that rated maximum is an absolute, do not go above it even by 1 watt, hence the need for a buffer of 1/2 their maximum rating inorder to cater for loud passages and peaks.
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I worked in an audio repair shop for a while and lost count of the speakers I replaced due to them being over driven.
A 100 watt amp driving a 100 watt speaker at full volume for hours isn't sensible.
I ran a mobile disco for 20 years and always had speakers twice the rating of the amp and never had any problems.
A 100 watt amp driving a 100 watt speaker at full volume for hours isn't sensible.
I ran a mobile disco for 20 years and always had speakers twice the rating of the amp and never had any problems.
Sounds like the coil is slapping the back plate.
Speaker being overpowered. Consider raising the high pass filter on the mid basses before you damage them further.
This statement suggests the problem lays elsewhere... Assuming you have substituted other pieces to rule each one out.
Thanks for the replies!
By "regardless of...input signal" I meant only no difference between L/R inputs.
Absolutely nothing is damaged...yet. The symptom is only at live SPL with significant mid bass program content.
From the replies, as expected, I presume the sum total cause is over-driven mid bass. Performance in every other respect is close enough to the best I've heard.
I very much wish the main speaker active high-pass crossover slope was tunable, and the pole by Hz from 80 to 100, rather than fixed 2nd order @ 80 Hz. Maybe increasing the slope or the pole to 90 or 100 Hz would eliminate the symptom. I suspect higher crossover slopes might be more acceptable at these lower frequencies than mid range frequencies where the ear has maximum phase sensitivity.
It occurs to me to play the CD (producing the symptom) on my inexpensive HT receiver, whose DD high-pass crossover is already tuned to 100 Hz. What is usually the slope of such crossovers? The processor sounds lame for music, but it might reveal a solution costing far less than adding a second mid bass per channel.
Maybe I can internally mod the active crossover pole, or replace my Dayton 950W sub amp/xo with Behringer's DCX 2496 + Hypex UCD amp.
By "regardless of...input signal" I meant only no difference between L/R inputs.
Absolutely nothing is damaged...yet. The symptom is only at live SPL with significant mid bass program content.
From the replies, as expected, I presume the sum total cause is over-driven mid bass. Performance in every other respect is close enough to the best I've heard.
I very much wish the main speaker active high-pass crossover slope was tunable, and the pole by Hz from 80 to 100, rather than fixed 2nd order @ 80 Hz. Maybe increasing the slope or the pole to 90 or 100 Hz would eliminate the symptom. I suspect higher crossover slopes might be more acceptable at these lower frequencies than mid range frequencies where the ear has maximum phase sensitivity.
It occurs to me to play the CD (producing the symptom) on my inexpensive HT receiver, whose DD high-pass crossover is already tuned to 100 Hz. What is usually the slope of such crossovers? The processor sounds lame for music, but it might reveal a solution costing far less than adding a second mid bass per channel.
Maybe I can internally mod the active crossover pole, or replace my Dayton 950W sub amp/xo with Behringer's DCX 2496 + Hypex UCD amp.
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So its only producing it on one CD? Can you give me a band name/song name and the timestamp where the problem occurs?
It sounds to me like smashing the coil former into the pole piece. I am surprised that if you are playing it that loud, you have any hearing left to know the difference. Just ignore it as I am sure the hearing aids you will soon need won't know the difference.
OK, speech aside. Now, if you put the subs right being the mains you can go to a higher crossover point, providing the subs can be well enough behaved to reach up to 150 or so. Many can't. Then run the AVR mains as "full range" pre-out to a real crossover, LR4 @ 150 to 200 Hz to an external decent power amp. That is the only way to get enough load off the mid-woofers. Adding a second pair is only good for 3 dB, so the click won't be as loud.
OK, speech aside. Now, if you put the subs right being the mains you can go to a higher crossover point, providing the subs can be well enough behaved to reach up to 150 or so. Many can't. Then run the AVR mains as "full range" pre-out to a real crossover, LR4 @ 150 to 200 Hz to an external decent power amp. That is the only way to get enough load off the mid-woofers. Adding a second pair is only good for 3 dB, so the click won't be as loud.
Hi, Max SPL will go up by a significant 6dB, rgds, sreten.
You can't expect small hifi speakers to do "live" rock SPLs.
Ember CD (Emily Williamson, Rebecca Sullivan)
Open All The Doors, jacket misplaced, U61657 on CD back
Cut 4, 1:26, and approximately 1:31, multiple loud acoustic drums
System employs pure analog Trinaual Processor for 3.1 music channels, perfect music/HT integration when video source is front projector with retractable perforated screen.
The same speaker symptom occurs playing Cream DVD, Royal Albert Hall (live 2005) Disc Two, Toad, Ginger Baker solo, again, at live SPL
We got this far...FYI: each of three front speaker channels (L/C/R) comprises two monitors in THIS unique vertical dipole array based on Toole's and LeJeune's earlier work. Two parallel monitors per channel = 2.65 Ohm minimum impedance @ which NC400 monos make 500W @ 1/3rd duty cycle (rated to 2 Ohms).
Interesting that even active crossed 2nd order @ 80 Hz, live SPL in a 3k cf fully carpeted room with light acoustic treatment requires more acoustic power than a sum total six Dynaudio Esotec 17WLQ can generate. 17WLQ are not pro audio, but they aren't wimps either. (The above described array trades 1.5 dB lower sensitivity for infinitely, and I mean infinitely better audio performance.)
Yes, I know what you mean, and would never expect as much from two normal "small hifi speakers" full range. The mains are active high pass crossed 2nd order @ 80 Hz, and as I further explained above, there is sum total six mid bass.
I hope (and expect) that increasing the slope and/or the pole frequency will eliminate the problem. I'm pretty sure I can cross my sub a bit higher.
Anyone want to loan me a Behringer DCX2496 for two days? I'll negotiate something for the loan, and of course pay round trip shipping/insurance.
That is probably sensible for a mobile disco but not for home audio. I say "probably" because I'm not familiar with the equipment for a disco, but I imagine for a disco that distortion isn't a primary concern nor amplifier clipping. The high-frequency section of disco equipment wouldn't be destroyed by clipping, I suppose, probably being something like a horn-loaded compression driver? I don't know, maybe you could tell us.
Anyway, for home audio, it's best I believe for the amplifier power rating to be greater than that of the speakers being driven for two reasons. First of all, assuming that the user knows not to turn the volume control of the amp too high, then the amp won't clip. If the amp clips, then the tweeters can be destroyed, assuming a multi-way speaker. Secondly, all amplifiers have greater distortion as gain is increased.
Regards,
Pete
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Thanks for taking the time to explain this in the way you did. I too thought his recommendation was quite the opposite of domestic high-fi, in which we generally prefer, and are safer with the amp making more power than the speaker power handling. Nothing like the a-musical spike from an over driven amp to really make a tweeter voice coil's day!
I think in my case the amp does make a bit more power than what the speakers can safely handle.
I'm surprised that you're managing to slap the coils against the back plate with a high pass in place, you must really be hammering things hard. Perhaps the cabinet alignment isn't properly suited. If the main loudspeakers are ported I'd suggest blocking the ports. Another thing to do would be to stand next to the loudspeakers and watch to see if the Dyn woofers really are moving enough to hit the end stops.
Thanks. That's a great tip.
Indeed, I have, unless they're misplaced, plumbing plugs for this very purpose. Earlier, inserting the plugs somehow lost some "liveliness" in the presentation. But since that time I've dramatically increased performance of the sub array, especially at higher frequencies. So I'll try this again tomorrow and report back to class.
I worked with live musicians, recorded Tower of Power, worked with Roy Buchanan, and am familiar with the audio performance of speakers that reproduce live levels without thermal compression. A long way of saying I enjoy brief live music levels when reproduced cleanly without modal effects.
The described main speaker array (and the sub array too) have almost no modal effects (the bass is +/-3 dB 20-100 Hz throughout the entire room including corners, without EQ and without acoustic treatment). Thermal compression and modal effects of most domestic systems do not lend themselves to realistic SPL. This system does not have those limitations, hence it invites listening levels much higher than average.
Thank you for solving the problem. I tightly sealed the ports (of all six monitors) with plumber's threaded plug with rubber seal.
Months ago I auditioned the main speakers plugged vs. open. Overall, at that time, I preferred the ports open. The mid range seemed to have a more lively, dynamic presentation, and larger/bettter spatial effects.
This time I repeated the test, knowing I wanted to increase power handling. I turned off the subs and the active high-pass remained in circuit.
I noticed the same differences as above. But I also noticed a slightly tighter focus, increased "tidyness" to the spatial presentation, throughout the range but the higher the frequency the greater was this effect. There was a welcome diminishing of modal effects in the lower register of the drum percussive effects.
Best of all, no more voice coil former slapping against the stop! Gone. I replicated the exact conditions under which it previously made huge metallic slap, crack noise.
Thanks 5th element!
BTW, in case you desire to experiment with "sealing" a port. Reliable source says there are potential negative effects (sorry, if I knew earlier what are the effects I forgot) resulting from partially sealed ports. Do employ proper air-tight plugs rather than a sock, etc.
I have six free metal plugs with wing nuts and rubber seals for 2" port if you want to pay for shipping.
I'm glad that helped solved the problem. The issue with ported enclosures, is that below the tuning frequency the excursion sky rockets, I figured if the speakers had a highish tuning then a large amount of low frequency content might be enough to upset things at a high enough level. Sealed enclosures don't unload so this would solve the problem if this was the case.
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