Hi there,
Ive got 4 subs loaded with the 18lw1400. I bought them 2 years agoo tested them and never used them actually. They where meant for my birthday once a year.
One time i accidently driven them on the high output from the driverack (80 hz - 18000 hz) and while it is strange it made one subwoofer sound distorted after that.
Anyway, today i was testing again and it looks like 2 of them sound distorted. I toke them apart to see if the conus and spiders are lose but it seems they are good. I also swapped them on other amp outputs but it doesnt make any difference.
I'm testing them on a synq 3k6 amp feeded thruw a dbx260 driverack with 30 hz - 80 hz 24db filters
I believe they have 2 (duo) spiders, could the inner spider be cracked and responcible for the distorted sound?
Sorry for my english, its not the best.
Ive got 4 subs loaded with the 18lw1400. I bought them 2 years agoo tested them and never used them actually. They where meant for my birthday once a year.
One time i accidently driven them on the high output from the driverack (80 hz - 18000 hz) and while it is strange it made one subwoofer sound distorted after that.
Anyway, today i was testing again and it looks like 2 of them sound distorted. I toke them apart to see if the conus and spiders are lose but it seems they are good. I also swapped them on other amp outputs but it doesnt make any difference.
I'm testing them on a synq 3k6 amp feeded thruw a dbx260 driverack with 30 hz - 80 hz 24db filters
I believe they have 2 (duo) spiders, could the inner spider be cracked and responcible for the distorted sound?
Sorry for my english, its not the best.
Oke i could do that, i remember back then i already tested one out of the enclosure with music and it still had a distorted sound.
Thing is i have a 15% discount that expires today
but until today i didn't know two of them had a distorted sound. The discount code only works for 1 product.
If i test with a 10/20 hz sinewave, what am i looking for? Still distorted sounds?
Thanks for your kind help.
Thing is i have a 15% discount that expires today
but until today i didn't know two of them had a distorted sound. The discount code only works for 1 product. If i test with a 10/20 hz sinewave, what am i looking for? Still distorted sounds?
Thanks for your kind help.
In effect, and the first elementary test is to know the state of each voice coil.
A simple reading of the DCR with an ohmmeter will clarify things. All must measure similar, below the nominal value of 4 or 8 ohms.
Simple, without removing the drivers
Oke i could do that, i remember back then i already tested one out of the enclosure with music and it still had a distorted sound.
Thing is i have a 15% discount that expires today
If i test with a 10/20 hz sinewave, what am i looking for? Still distorted sounds?
Thanks for your kind help.
if the coil is overheating it may have some short circuits, but still work, and in such low frequencies it will not make audible differences easy to detect. You should compare between them which speaker sounds "different" .....
All 4 subs measures between 5,28 ohm and 5,31 ohm, i remember measuring it before, so no problems with the coil itself i guess.
When not muting the tops (jbl mrx515) its like the set is doing oke and the distortion is not audible.
When at pretty loud and with tops on to mask the distortion, there seems to be no volume difference between the 4 subs.
I could measure the db's of each sub, ive got a db meter here lying somewhere. But i don't think it will measure large differences since my ears dont tell volume difference's.
I also got some measure mics here as wel, a sonarworks measure mic and a cheap behringer measure mic. I use them for room eqing my studio.
Could i measure and see problems if i use other software then my room eq software? I remember long ago i used some software to measure my studio and that software plotted al kind of graphics (waterfalls etc etc)
When not muting the tops (jbl mrx515) its like the set is doing oke and the distortion is not audible.
When at pretty loud and with tops on to mask the distortion, there seems to be no volume difference between the 4 subs.
I could measure the db's of each sub, ive got a db meter here lying somewhere. But i don't think it will measure large differences since my ears dont tell volume difference's.
I also got some measure mics here as wel, a sonarworks measure mic and a cheap behringer measure mic. I use them for room eqing my studio.
Could i measure and see problems if i use other software then my room eq software? I remember long ago i used some software to measure my studio and that software plotted al kind of graphics (waterfalls etc etc)
Action Henk,
The suggestion to free-air drive them at low Fq is a good one. They will produce significant excursion at a fraction of their normal power rating. While stroking, if the VC windings have come loose or VC has become non-centered in the gap, Etc, you will certainly hear it.
I looked up that Sync 3k6 = 1600WattsRMS @ 4-Ohms, yeah that maxed out at mid Fq going to these 18's may have been too much - depending for how long that occurred?
And while a DC resistance measurement is a good check for really scorched VC's, it won't detect all defective CV coils.
The inner Spider coming loose is a possibility but is less likely if the visible outer Spider is still intact. Usually the inner Spider is either epoxied and/or fastened in place. If it has let go - carefully pushing in the cone you should be able to feel a reduced resistance to movement compared to a good unit.
Also check for the obvious (again), tinsel leads slapping the back of the cone, tears in the main suspension, debris sucked into the magnet vent(s), cabs are coming loose and vibrating, are there passive crossovers in the cabs, check wire connection points for good connection?
If you have the cash, getting a spare driver at a discount can never be a bad thing.
The suggestion to free-air drive them at low Fq is a good one. They will produce significant excursion at a fraction of their normal power rating. While stroking, if the VC windings have come loose or VC has become non-centered in the gap, Etc, you will certainly hear it.
I looked up that Sync 3k6 = 1600WattsRMS @ 4-Ohms, yeah that maxed out at mid Fq going to these 18's may have been too much - depending for how long that occurred?
And while a DC resistance measurement is a good check for really scorched VC's, it won't detect all defective CV coils.
The inner Spider coming loose is a possibility but is less likely if the visible outer Spider is still intact. Usually the inner Spider is either epoxied and/or fastened in place. If it has let go - carefully pushing in the cone you should be able to feel a reduced resistance to movement compared to a good unit.
Also check for the obvious (again), tinsel leads slapping the back of the cone, tears in the main suspension, debris sucked into the magnet vent(s), cabs are coming loose and vibrating, are there passive crossovers in the cabs, check wire connection points for good connection?
If you have the cash, getting a spare driver at a discount can never be a bad thing.
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Does that mean before the problem arises?
If so, then do it again .....
It is very strange that the speaker is the culprit of the distortion, is a transducer, converts electrical energy into acoustic energy.
If it's not broken, and the coils are fine, I'm sorry I can not help.
PD: I am involved in a huge OT, but I think it's the case.
I'm from the old school. I bought a Yamaha receiver with DSP a few years ago. The only fact of wanting to regulate the differences of time delay between the front and rear speakers with the intuitive remote control nothing exasperated me.
It's on the wagon waiting for some better use, like stereo amplifier only, but for high-level sources only, because these Japanese geniuses did not even incorporate a magnetic-phono input. And it turns out that vinyl has resurfaced ... hahaha
So it was only my two cents, I hope the buzz is solved, (I hate them, I understand your annoyance, and I'll keep an eye on this thread.)
PS: I am convinced that in electronics, mixing components of different brands and characteristics is the same as when you make a PC, you bought the last hardware for Win 10 but the software no longer includes Win 7 ...
Analog equipment coupled with converters and / or digital processors, problems in sight.
I can not transfer my precious Sony D8 cassettes to digital media like the DVD with my netbook.
USB came and all motherboards no longer incorporate the IEEE 1394 Fireware port, there are no portable converters for netbooks or laptops ....
I would have to put together a new dedicated PC with a Fire Express PCI badge ... is this a technological advance or a step backwards?
Those ohm measure are from today,
It has been like two years ago i guess, if i remember right it was a very short time and not anything close near full power. They can handle 1400 watts at 8 ohm each (7000 watts peak). The synq 3k6 gives 900 watts at 8 ohm each (parallel daisychaining the subs) I never clip and have limiters and gainstaging all setup in the driverack 260.
Well i think i should do that, with discount a spare unit costs me 270 euro. 'm gonna do some more testing before i order one i guess.
If resistance is ok measure Z (How to Measure Speaker Impedance (with Pictures) - wikiHow)
You need a good dac with any software tone generator, send this to your amplifier (which channel works without distortion on the good woofers) and use a resistor.
Compute the Z curve, this will detect any failure of the VC , and parameters of the magnets and suspension. Z curves will reveal any difference.
Also, use your hand and push on the woofer as much as possible in a linear motion, use just enough force to move the X max. You should not feel any rubbing and paper on paper type of friction which indicates the speakers needs to go to repairman.
You need a good dac with any software tone generator, send this to your amplifier (which channel works without distortion on the good woofers) and use a resistor.
Compute the Z curve, this will detect any failure of the VC , and parameters of the magnets and suspension. Z curves will reveal any difference.
Also, use your hand and push on the woofer as much as possible in a linear motion, use just enough force to move the X max. You should not feel any rubbing and paper on paper type of friction which indicates the speakers needs to go to repairman.
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ActionHenk,
Well if you didn't hit with too much pwr, then I'm leaning towards the cabs are start loosen up and rattle. I've seen FLH cabs make all kinds of funky noises with the front braces becoming unglued on one side.
I believe the Euro is about equal to a USD, so 270 sounds like a good deal!
Well if you didn't hit with too much pwr, then I'm leaning towards the cabs are start loosen up and rattle. I've seen FLH cabs make all kinds of funky noises with the front braces becoming unglued on one side.
I believe the Euro is about equal to a USD, so 270 sounds like a good deal!
Well, i had 3 units pulled out the enclosure yesterday, and they behaved exactly the same in the open air. They where distorted on low power (80 watts at 8 ohm max) the good unit also distorted in open air.
I will test again and swap the distorted units in the enclosures that don't distort to see if the enclosures are the source of the problems.
I will test again and swap the distorted units in the enclosures that don't distort to see if the enclosures are the source of the problems.
It was with another amp, but feeded from the same source (ecler hak 380 mixer to driverack 260, settings: 30hz till 80 hz, filters: linkwitz riley on 24 db slope. Already tried 12 db slopes and Butterworth filters with both slopes but no difference.
The amp wich i used for air free testing was a oldschool technics se-9200, wich i use as a amp for my studio monitors because its so clean. I didn't clip it.
Anyway, my findings is that a good driver unit also distorts without the enclosure, it distorts exactly the same like the other two when air free. Is it maybe that these units really need a enclosure for air pressure? After mounting the good driver unit back in his own enclosure it was again distortion free.
Like i said i have to swap units in enclosure's to be sure, but working with 50 kg enclosure's and 14 kg units is not something i can do in a minut without hurting my back.
The enclosure's are very heavy built, 28 mm plywood with 56mm plywood cross rugged constructions inside. So it would be strange if a enclosure is the source of the problems but ofcourse it can be. btw i really hear the distortion coming from the conus. Its like a 150>250 hz distorted sawtooth. You know like a bass synth feeded thruw a distortion pedal, thats the sound.
Thanks everyone for so far, i will test more but since the weekend is over testing time is limited.
The amp wich i used for air free testing was a oldschool technics se-9200, wich i use as a amp for my studio monitors because its so clean. I didn't clip it.
Anyway, my findings is that a good driver unit also distorts without the enclosure, it distorts exactly the same like the other two when air free. Is it maybe that these units really need a enclosure for air pressure? After mounting the good driver unit back in his own enclosure it was again distortion free.
Like i said i have to swap units in enclosure's to be sure, but working with 50 kg enclosure's and 14 kg units is not something i can do in a minut without hurting my back.
The enclosure's are very heavy built, 28 mm plywood with 56mm plywood cross rugged constructions inside. So it would be strange if a enclosure is the source of the problems but ofcourse it can be. btw i really hear the distortion coming from the conus. Its like a 150>250 hz distorted sawtooth. You know like a bass synth feeded thruw a distortion pedal, thats the sound.
Thanks everyone for so far, i will test more but since the weekend is over testing time is limited.
So it sound like at least some of these drivers must be ok.
So I'm thinking something up the signal stream is causing said distortion. Take the mix board, the DBX unit, along with all the xlr/trs cables out of signal path.
Feed a CD player or something directly into your amp (start with amp gain all the way down. If your amp has a low-pass crossover built in engage it. Your probably going to need single-ended to balanced adaptors/cables.
See if the distortion disappears.
If not, I'm kind of out of sugestions.
So I'm thinking something up the signal stream is causing said distortion. Take the mix board, the DBX unit, along with all the xlr/trs cables out of signal path.
Feed a CD player or something directly into your amp (start with amp gain all the way down. If your amp has a low-pass crossover built in engage it. Your probably going to need single-ended to balanced adaptors/cables.
See if the distortion disappears.
If not, I'm kind of out of sugestions.
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