i am using internal xo,which came with the speakers
all tests done with power amps disconnected.
the problem{ going pop{broken}only happens when the speakers are driven in bi-amp config,and its the amp which is driving the high/mid drivers that blows up .
when using only one amp,in bi-wire config,everything works,all be it the sounds quality is slightly off,but i would have thought that to be ok,that why i bi-amp,for better sound quality.
to add to this,i changed out the xo caps for better ones two years ago,and after fitting them ,i tested the input speaker terminals for the correct ohms reading and all was good,but something has changed.
regards Mark |
i would also upload some photos, but as this is my first ever use on this site,im not sure how to do this, any help appreciated,
mark |
Hi Guys,thankyou so much for all your help,but i still dont see a solution to this problem,in my opinion there is shorts in both xos,please see below-
LEFT SPEAKER /
RIGHT SPEAKER
speaker terminals with everything connected on both speakers
MID/HIGH 0.0 ohms /
MID/HIGH 0.0 ohms
BASS 7.9 Ohms /
bass 6.8Ohms
DRIVER TEST DISCONNECTED FROM X OVER
TWEETER 8 OHMS /
7.9 OHMS
MID 6.3 OHMS /
6.2 OHMS
BASS 6.1 OHMS /
6.0 OHMS
CONTINUITY TEST ON X-OVER WITH DRIVERS REMOVED USING DIODE FUNCTION
between positive and
negative on x over
HF 000.2 {dead short}
/ 000.2 {dead short}
MF 000.5
/ 000.5
LF OL.
/ OL.
MID HIGH INPUT IP OL. /
OL.
BASS INPUT OL. /
OL.
OL. BEING NO CONTINUITY
TEST TESTED AT/ON X-OVER SPEAKERS CONNECTED OHMS
HF 0.0002 OHMS /
0.002 OHMS
MF 0.0001 OHMS /
2.0 OHMS
LF 6.4 OHMS /
6.3 OHMS
ive also now removed one lead from all the caps on one xo,and tested them with a cap meter,all caps are the correct uf ,within spec,can anyone tell me where to go from here,
thankyou again for all your kind help.regards Mark |
that all sounds fantastic Fiesta,ill get on that today,taking photos,ill try draw a schem.but its difficult, but ill do my best,thankyou so much for your help here,its so much appreciated,im sure its some thing simple in the xo,but i cant see it,but it strange how both have gone the same way,caps where all changed out 2 years ago,but ill test them all again.
kind regards
Mark |
imhififan1,thankyou for that.
regards
mk |
im trying to upload photos,but it keep coming up with
"
Title has already been used on one of your systems."
I DONT UNDERSTAND WHY ?
REGARDS
MARK |
OK,IVE MANAGED TO SAVE THE PICTURES,but i am now strugling to put them on this page,im so useless !!,
regards
mark |
OK,lets have a go with this,i have asked wilmlow for adivice ,schems and any help they can give me,but they just say send it in to us,and are not coming foreward with any other help,which is a shame,as these speakers were not cheap,for me anyway..
ive checked the AC voltage on both amps
amp driving mid/high which has popped twice, now repaired but running in another system {all good}
readings left channel -0.001v {AC] right channel -0.001v {AC]
good amp[never popped} runs bass, left channel 0.002v [AC]
right chan. 0.002v AC
all other components turned off, except amps
At this point i should add a little more history,after i got the amp repaired and plugged it back into the system,after about 3 hours it went pop again,so i sent it back to the technican,after ttwo days of him looking at it,he sent me an email asking me to checked my speakers,which is when i realised that was where the problem was,so i dont think it is either amps,i now run the repaired amp in another system which seems to be good,so i think the problem is in the crossovers,as all driver read the correct-ish ohms,but what i find very strange,is that both xo s have gone us,this is a puzzle to me.
I am totaly open to any options,but as a retired guy,money is a factor,but would love to find out the fault,but if its easier,i have another two power amps in boxes,but there are lower in power {Arcam Alpha 9p s}.
Another question ,is it not AC at the speaker terminals ?,im not sure!!
I have removed the caps from one crossover{or one lead} and they check out to be ok on all caps,
What do you think maybe suspect on the wiring,or is it just my soldering ?.
ANYWAY I THANK YOU SO MUCH FOR ANY HELP
regards Mark
PS if you can give me a day to work out a schem.that would be great.
Mk |
thankyou all again for this help,i uploaded a schematic of the crossover wilmslow have now sent me,i will test and check all readings and offset dc today,then i will get back to you all.
so many thanks
regards
mark |
shorting links on speaker binding post havent ever been used,to go from bi-wire to normal two wire ,or bi-amp to normal two wire config
|
fiesta-"
an ohm meter test between the HF+ and LF+ terminals should be 0.0 ohms. Same should be true of the HF- and LF- terminals. This can be measure at the speaker or amplifier terminals."
measurements for above,taken on the x-over
both OL ,ohms |
Hi Guys,sorry for the late reply, my wife doesn't see my urgency about this,so im going with the flow!!,please bear with me.
So,i now sat here with one of the crossovers multi meter in hand and i will try answer al the questions
DC offset,taken at speaker cable end ,speaker removed
repaired amp mid/high left chan 0.000 right chan 0.001v {DC]
bass amp Left chan 0.006 Right chan 0.002 {DC]
on xo IP pos and IP neg have good solder joint{tested good}
resistance between IP POS And IP neg -OL ,
Multi meter checks out good,i have two of them ,both reading close enough.
No visabe shorts on board or speaker terminal board
mid speaker cable going to driver,dead short.no driver connected
tweeter spaker cable going to driver ,dead short,
no driver connected
bass cable going to driver. OL,
no driver connected
ALL 3 OF THESE TESTS WERE ALSO TAKEN FOR XO PCB END
internal speaker cable from input to xo,No shorts
Test for shorts done at speaker cable imput {4 terminals}for bi-wire and Bi amp,inputs at the back of speaker boxes, NO shorts
to test resistors do i need to remove one side from pcb xo,ive just tested one [5w2R2J] and it showing a short,still fully soldered ??.
on the comments about capacitor placing on top of resistors etc,i do see what you mean,it was my first time replacing the caps on an xo and the leads where short,but i can remove the all and try again,its just that these caps are a lot bigger than was what installed at factory,sorry for my rubbish placement.
so all in ,i see no physical short, wires touching, all soldering has been tested for contin.all good,no dry joints,no cable fraying,no cable rub throughs,from vibration,it seem to me listening to you guys i maybe need to remove all components and test them,would i be wright in that assumption
,hope the wife doesnt mind me spending the next day or two doing this !!!,shes wanting a garage built !!!.
Anyway guys,i hope ive answered all you questions,i sure do appreciated you all taking the time out to help me with this,.
Kind regards
Mark
PS,im still open to tri-amping if you think it might be a better solution ,in the end,fiesta,but would be great to find the problem first,Anyway
cheers guys |
Hi guys, sorry for the very late reply in my/your quest to sort this out,ive done a couple of thing since, taken advice on multi meter/s, fitting fully charged battery's in the digital and analogue multi meters,both tested by using an 8ohm resistor, I use for running in component/gear, just incase, removed all wire to and from the x over and cleaned the board,and flowed every joint,so there no chance of dry joints and shorts,also i have done a continuity test from every component lead to pcb tracks,all joint good, please find results of questions asked.
multi meter set to ohms-
between mid pos and neg 2.7 ohms
between tw pos and neg 0.002 ohms
mid/high inputs OL {held on for 5 secs}nothing changes
mid/high inputs {reversed} OL{held on for 5 secs}nothing changes
when run with one amp,in bi-wire mode both pos are NOT connected the same goes for the neg wires,the amp has 2 sets of switched speakers terminals,i use one set for the bass and the other set for the mid/high,so the two speaker cables do not touch each other
resistor showing short{5w2R2J},which i measured using continuity mode,just above IP neg,when doing an ohms test is reads 2.3ohms
Diode test on mid/high -OL
when reversed is flashes 2.2xx,then goes to OL
every time i reverse leads it flashes something {2.2xx}not sure its voltage,it doesnt tell me that
|
i had a good play about with them both today,x-overs,couldnt find a problem ,maybe i should just strip them down,or one,check all parts then reasemble,not sure how to test the inductors though,as i can see i dont know enough, I can test parts but all this equations for test with a multi meter only,idont evem know what mH is !!??.Didnt think this would be that hard, obviously im wrong again.
cheers guys for all your help |
further to reply to imhififan1 im not sure how to test for what your asking
"
Without drivers connected,
The HF measurement should equal to the DC resistance of the 0.22mH inductor.
The MF measurement should equal to the DC resistance of the 2.5mH inductor + 2.2Ω.".
Not sure what 0.22mH is and also 2.5mH inductor +2.2 ohms,i know what the inductors are but not sure on mH.
Also i have found that one of the capacitors has a dead short short when tested in dioode mode,{still soldered into pcb},on both x-overs, when the rest show OL,not sure if that has a bearing on anything, just throwing it out there.
Any guys sorry again for the late reply,i hope your all still speaking to me, thankyou again for all your help.
Kind regards
Mk
ps i have posted some more pic of cap showing short and the resistor ive tested
thx again MK |
i think we may have a misunderstanding some times about ,when i use a diode test and ohms test,i think i haven't explained it well enough,or used the wrong test for finding this fault
originally when i tested the speakers{in the beginning}there was NO reading on ohms for the test when testing the mid/hi speakers on the terminal speaker posts on the back of the speakers,
please see first tests
"
LEFT SPEAKER /
RIGHT SPEAKER
speaker terminals with everything connected on both speakers
MID/HIGH 0.0 ohms /
MID/HIGH 0.0 ohms
BASS 7.9 Ohms /
bass 6.8Ohms
DRIVER TEST DISCONNECTED FROM X OVER
TWEETER 8 OHMS /
7.9 OHMS
MID 6.3 OHMS /
6.2 OHMS
BASS 6.1 OHMS /
6.0 OHMS
CONTINUITY TEST ON X-OVER WITH DRIVERS REMOVED USING DIODE FUNCTION
between positive and
negative on x over
HF 000.2 {dead short}
/ 000.2 {dead short}
MF 000.5
/ 000.5
LF OL.
/ OL.
MID HIGH INPUT IP OL. /
OL.
BASS INPUT OL. /
OL.
OL. BEING NO CONTINUITY
TEST TESTED AT/ON X-OVER SPEAKERS CONNECTED OHMS
HF 0.0002 OHMS /
0.002 OHMS
MF 0.0001 OHMS /
2.0 OHMS
LF 6.4 OHMS /
6.3 OHMS
what i see,is that when testing a speaker from the speaker cable posts,disconnecting from the amp,i should see how many ohms the speakers are,in this case they are 8 ohms speakers,and i have tested them on other ocassions,after re-wiring them once another time when i re-capped them,just as a check for shorts or problems and they have always read in the ball park of between 7.8ohms and 8ohms,for both bass and mid/hi ,now it doesnt read that,the bass is ok but the mid/high reads 0.0ohms,i only checked them,when my technican asked me to after the first time he repaired the ampand it blew,and sure enough there was a problem,does this throw any light on what your thinking,or have i really badly explained the problem,really sorry if i have.
regards
MK |
pragmasi-
1) Original test with everything assembled showed 0Ω resistance across the MF/HF +/- terminals on the back of the speaker.
2) Those terminals connect directly to IP+ and IP- on the crossover PCB.
3) With the crossover disconnected the DC resistance between IP+ and IP- was open circuit.
If points 1-3 are correct and you’ve put it back together and measured 0Ω across the loudspeaker terminals then there’s a short somewhere between the terminals and where the wires connect to IP+ and IP-.
totally correct
4) With everything disconnected from the crossover you measured the resistance across the copper you have marked M+ and M- and got 0Ω.
-not sure where i said that-
No it reads 2.7ohms
hope that helps.
Mk |
Pragmasi-im really sorry,but there are no open circuits, i have closed circuits{shorts},which are the problem,surely if i have a short internal of the x-over ,before it reaches the mid and high drivers this will draw current.to be honest,i thought i knew how to test a speaker box,it seems im totally out of my depth here,which i knew,but was just asking for basic help,101 style,im no way an electronics engineer ,hobbist at most,not even that,so giving me eqations to do ,when i dont even know what the sybol mean ,is a strtch too far,its like me asking to to calculate the dwell angle and timing on a camshaft for a super charged car,if you dont know,it will take a long time to learn,i have one simple question why does the mid/high on the crossover have a short within the x-over,when the bass driver does not,im just not grasping even that,and how come there is not an ohms reading for the mid/high at the binding posts,please please excuse my ignorants,
mk |
ps was that pragmasi or eric which posted the equation post ? |
pps,just to add to my explanation ,i feel that there might be a value issue here,what do you guys think,ive possibly fitted the wrong value caps{i dont think i have,as i would have compared them before fitting}but they are definitely different type of caps,ill dig the old ones out and put the old type and what i replaced then with on here later,but today i have to do some concreting, my wife is going crazy.
thanks again guys
M |
thank you all guys i am so honoured for all your help,but i think i am going to go for the simple fact,that,i think all these problems may have started when i changed out all the caps,on the cross over,im going to find the old ones which i removed,check there values again ,against the schematic i have uploaded ,and maybe ask you guys if they are compatible/same,like for like to do the job,i received a private email,that explained that they maybe different,although i did get them from Wilmslow audio and stated they where for an upgrade for my speakers,but it just might be worth trying the obvious stuff first,as soon after the change out,is when this problem started,2 years ago.still dont understand why it works with only one power only though,and not two.weird.
Just to answer your last question though.
pragmasi,the the binding posts holder is plastic,no short there.
i connect the speakers via two cables{pairs]to a four post bi-wire termial posts,in one amp mode,i use the same cables and posts ,but use the two sets of speaker post on the back of the amp.
Hi fiesta the blue circled cap is 6.8uf 250v cap,which is the one that looked like it had a short,but after desoldering it from the board ,it tested on,no continuity and good cap testing values,so was red herring,someone said it was because it was in parallel with other parts reason for show a short
fiesta-
"
In one photo I can read 3.9uf/250V. When you drew and label the components on the circuit board the 4.2uf should have been 3.9?"
I didnt draw the x-over i received it from wilmslow audio and posted it here,
maybe i have the wrong caps,i will dig out the old ones and check/compare.
hififan,i checked out the link,had a look at the schem,that one is similar,but are they not all individual to every speaker?,im not sure.
rodman,i dont really want to go down that route of testing with expendable drivers and amps,its exspensive, when things go pop,but thanks,plus the speakers work,but after a few hours the amps goes pop,so i dont think its an obvious fault,but possibly a high draw problem,putting strain on the amp driving the mid/high drivers,but thanks for the input.infact thank you all for your imput.
im going to check out the cap values and tyes again ,against that schematic.
|
pps,does any know how to remove hot glue ??,the easy way |
ps,thankyou thomas for the explanation and time,you know who you are. |
Hi rodman,whn everything is connected in a one or two amp system is in use ,everything sounds great,the sound is amazing, slightly better with two power amps {obviously},but nothing is a miss,its just that it keeps blowing one amp,the one driving the mid/highs,and that is the only problem,i just cannot find out why,but every time it blows an amp,it cost me a fortune to send to Sofia about 200 miles from where i live in Bulgaria,as its the only tech i can find in the country,postage alone is £50plus the repair another £100 plus.
gregm3,iits not esay in bulgaria to find a electronic HIFI tech,,to find any tech is a job in its self,a good one is like rocking horse ..
Cheers guys Mk |
ok i have uploaded my original readings,via a picture.
later guys |
wow,such a lot of input,thx guys.ok
Fiesta 1st,"
Are you SURE that when you bi-amped the speakers after getting the amp back from servicing that you didn't forget to remove the second set of cables to the low and mid/hi inputs? "
the two amp to speakers where wired correctly,the cables are all marked up correctly left/right,plus minus, and they have different plug,banna and another type,so it impossible to mix them up,plus i dont ever use jumpers on the back of the speakers.
Sorry,not parts list available, he wouldn't give me one,i asked but got no reply on that score.he said it was getting too hot and fitted a fan after repair,which i wasnt keen on ,as i see that as covered up WHY it is getting too hot.
On doing re-work,all i have done is,removed the cables from the x-over and tested continuity from every component to the track on the PCB,every thing checked out,also i clean up the board with pcb cleaner,to remove flux stains.
change out from ,
4.2uf and the one you installed is 3.9uf,may not be correct,im still looking for the old caps,to verify the are the same type,like for like,as wilmslow may have updated that schem,as the speaker evolved with different drivers in it,as i have 100s and 100s of caps from different projects,im just struggling, at this moment to put my hands on them,
Rodman- the difference between using one and two power amps,i heard my system using two and heard it using one,i dont want to back to one,tow sounds amazing,one sounds ok,im sure you know what i mean,ive been evolving this system for 30 years,i dont want to loose 10 of them,sorry.
"
Meanwhile: take the Wife OUT for some Meshana Skara or Mousaka and help her relax! Top it off with some Marudnik (are wild berries in season over there?) and make her love you, again!"
30 years of Hifi, i dont think one meal will cover that....you know how we get!!.but thx for the advise.
imahififan- no short,,the picture shows a little solder splash,where i DE soldered the other x-over cap to check it,but and in that picture the cap lead is not soldered down,but well spotted, that is studying these pics very closely thx.
So guys,it looks like we are running out of ideas,which makes me feel ,like it might be some thing else,as you guys would have picked up on it,
I know this may sound stupid,so when i test a speaker ,at the binding posts,disconnected,i cannot just put the mul/mtr in ohms and check to see what ohms the speaker is/are ??.as thats what ive done for years !!,im sure that when ,infact i know thats what i did when i found a a tweeter blown and what i did when i re-capped the x-overs and when ever i test a speaker to see what ohms it is,totest its ok ??.
just a little note,when these amps have blown,they have made the same noise both times ,through the speakers,just like a little pop,then the amp goes into alarm,exactly the same sounds,just thought i would through that in there,
when ive tested these speaker in the past,the way i have expalained ,i have never had 0ohms for the mid/high ,im pretty sure of that,im just putting it out there,
Another thing ,because the amp is getting hot{but they do run hot [Arcam Alpha 10Ps} and they are 25 years old,do you think i should give them a re-cap?,will this possibly bring them back into spec and cool down a little,.Anyway ill get back to my concreting.
cheers guys
|
ps,just found this in an old book
7.1ohms LEFT MID/HIGH 8+6.4=4+3.2=7.2
6.8ohms LEFT Bass 6.8
7.0ohms RIGHT MID/HIGH 7.5+6.5=3.75+3.25
6.8 ohms RIGHT Bass 6.8
i must have taken these measurements of the speakers a few years ago,which are different to the measurements that we have now,i know these are the measurements as i only own one pair of bi-wirable speakers |
thankyou for that,some thing seems a miss,i do read 0ohms,i also found my orignal written values also this morning when i first started investigating all this,
Tell you what,you guys have put so much time and effort into this,this weekend i am going to clean everything up and start again,i will take variuos readings on crossovers,re-assemble the whole two speakers and do it all again and then i will come back with a list of readings,it seems thats all i can do,i really appreciate all the help,i really do.
And thank you all again
Mk |
where i have written" speaker terms with everything connected" ive written Hi and low, which means mid/high and bass,on the speaker posts,just to clear that.
thanks guys |
Hi Tim,so sorry i havent gotten back to you,ive been trying to to fix this problem online with another guy,but for me,my end,my laptop is very old and slow,and have been waiting to receive a new one from the UK,and it all takes time,living in Bulgaria,thank you so much or your offer,it is very much appreciated, I wish you all the luck in the world,with your new job and thank you again for your amazing offer. kind regards mk. |
