Hi
Just opened my Jamo E650 was doing some mods to my Jamo E6 center i will post the mods later here so i was wondering what kind of mods can you do to the crossover on the E650.
Here is a full video of every component.
https://youtu.be/uhHbDJsewJI
Just opened my Jamo E650 was doing some mods to my Jamo E6 center i will post the mods later here so i was wondering what kind of mods can you do to the crossover on the E650.
Here is a full video of every component.
https://youtu.be/uhHbDJsewJI
Interesting but i think instead of the protection i would put 2ohm resistor because the part itself have 2ohm when cold. The capasitor is already 3.3uf do you think it will be better to put new MKP 400V capasitor?
The schematics you provided is not correct. There is no coil on the tweeter. The coils are for the bass and middle speaker. Tomorrow i will draw the exact schematics so we can draw modifications on the base image.
I always thought that the speakers lack of middle to high freq. The tweeter is more than ok.
The modification i have made on the center speaker E6 Cent, is cut down the coils for the middle tone from 1.2ohm to +- 0.8ohm. Removed half of the wire and that made massive difference in middle to high tones. It liven up the speaker. The tweeter was dried up so i removed the ferrofluid and now it sounds like new.
So, removing the protection and 2ohm resistor in the place of it. Adding a coil (the stock crossover doesnt have a coil on the tweeter) and a resistor. Btw the speakers are 4ohm not 8 so... Another thing, any thought for the middle speaker. The sound is like middle to low there is a lack of guitar volume and crispness 😛 (if that is a word...im from macedonia so english not my native laguage )
Do you think 4.7uf MKP resistor will be a better choice for more bandwidth on the tweeter.
Do you think 4.7uf MKP resistor will be a better choice for more bandwidth on the tweeter.
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Lack of middle is probably more too much bass, a problem with 2.5 ways, which do full 6dB bafflestep correction. Keep them away from the wall.
For 2dB more treble and mid at crossover, the below circuit looks OK. Won't strain the (8 ohm?) tweeter any more than it is already. The 22R is important for a clean sound IMO.
Now I don't know what the mid's coil is, but reducing it will certainly lift the midrange. I tend to use 1.5mH with 6.8uF on a 6" bass, rather than 2.2mH. It's livelier.
For 2dB more treble and mid at crossover, the below circuit looks OK. Won't strain the (8 ohm?) tweeter any more than it is already. The 22R is important for a clean sound IMO.
Now I don't know what the mid's coil is, but reducing it will certainly lift the midrange. I tend to use 1.5mH with 6.8uF on a 6" bass, rather than 2.2mH. It's livelier.
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Have you made any measurements? Frequency and impedance? IF you want to make changes to the crossover measurements should be your starting point. It might seem hard but actually its harder to just change stuff out. Youre basically shooting in the dark here and it could just as well make it worse..
Well. Do we even know where the acoustic crossover is? If we dont know what we are changing from we could be adding a big bump or suckout in frequency response. Of course we could just keep changing stuff till it sounds OK. But imo its a waste of time, why not just do it the easy way and propably get a better result?
Some tweeters have a sharp knee and then falling response so if you just look at the components you may think its a high first order crossover. But if you look at the acoustic response you could have a low crossover wich fall of at 24db/oct
Some tweeters have a sharp knee and then falling response so if you just look at the components you may think its a high first order crossover. But if you look at the acoustic response you could have a low crossover wich fall of at 24db/oct
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To be serious, the Jamo E650 seems to be your regular 2.5 way speaker with 165mm paper bass drivers. Not my cup of tea, as it goes.
PEERLESS-NOMEX-164
Obviously simplified for commercial reasons. But nevertheless demanding a second-order tweeter. 4.7uF and 0.2mH ought to do it. 😀
PEERLESS-NOMEX-164
Obviously simplified for commercial reasons. But nevertheless demanding a second-order tweeter. 4.7uF and 0.2mH ought to do it. 😀
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What? You think he should build that speaker instead? Or do you just mean that since other propably better speakers have second order tweeter crossover you could just use the same on this one? They both have paper bass drivers so it should be kind of the same thing??:/
The component values in the crossover is not translateable to a frequency response. You _need_ the raw drivers response in cabinet and impedance since it all interacts. Pretty basic stuff really.
The component values in the crossover is not translateable to a frequency response. You _need_ the raw drivers response in cabinet and impedance since it all interacts. Pretty basic stuff really.
Ok so, because of my location and financial reasons i cant replace drivers. So the best option is to do only one speaker with 4.7 and 0.2mH and 2ohm resistor and compare it to stock. The speakers are 6.6ohm just measured them. (they are probably 6 😛 since on 8ohm speakers the same multimeter shows 8.4ohm). Now about the parts. MKT or MKP ? here is a link from the part ???????????, VS-C4.7 250MKP | Loging Electronics mind you its not stock so i will have to wait 🙁 btw what od you think about this schematics only for the tweeter http://i.imgur.com/o99ut.jpg (that 6.8 and 10uf is making me nervous :S)
Time for a review.
The above circuit is almost exactly same target response as the single 3.3uF and 2R circuit fuse. The 15R or 22R gives the amp a better load at high frequency. So it sounds smoother, you follow? In fact I was using 22R in modelling it this morning.
This one gives you 2dB more treble and midrange at crossover, whilst keeping impedance comfortably above 4 ohms.
Both have much better phase alignment than the single 3.3uF.
You can, of course, add a 1.5uF MKP to the 3.3uF to get to the same place.
If you are undecided about treble level at this stage, a 0.3mH air coil could be a good compromise. Hardly a critical circuit.
The Jamo concert 8 circuit is for a completely different 2 way metal bass speaker. Forget about it.
The above circuit is almost exactly same target response as the single 3.3uF and 2R circuit fuse. The 15R or 22R gives the amp a better load at high frequency. So it sounds smoother, you follow? In fact I was using 22R in modelling it this morning.
This one gives you 2dB more treble and midrange at crossover, whilst keeping impedance comfortably above 4 ohms.
Both have much better phase alignment than the single 3.3uF.
You can, of course, add a 1.5uF MKP to the 3.3uF to get to the same place.
If you are undecided about treble level at this stage, a 0.3mH air coil could be a good compromise. Hardly a critical circuit.
The Jamo concert 8 circuit is for a completely different 2 way metal bass speaker. Forget about it.
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Ok, ptc protection, i will leave it as it is because i just remembered that when my cousins children turn up, they turn the volume knob on the yamaha rvx477 that the tweeter turns off itself. Now for the 4.7uf, i will remove the 3.3 and get the mkp provided in the link above (that should give me more frequency on the tweeter). As i understand for the PTC protection to stay i will have to use 15ohm (not 22R) resistor in parallel to the tweeter and 0.20mh coil, is that right?
Another question, the middle bass speaker, it is in enclosed speaker box, will it be smart to put bipolar capacitor in series with the speaker removing the bass just a little, let say 100uf or leave it as it is and only try with another coil (the 1.0mH) this one ?????, VS-5014 | Loging Electronics
i must decide what to do so i can order the parts from the shop in my city because most of the ones I need are not in stock.
another thing i will solder the wires on the speakers because the connectors are very sturdy and put more wood glue inside the speaker corners. One of the speakers on certain frequency you can hear the wood oscillateing.
Another question, the middle bass speaker, it is in enclosed speaker box, will it be smart to put bipolar capacitor in series with the speaker removing the bass just a little, let say 100uf or leave it as it is and only try with another coil (the 1.0mH) this one ?????, VS-5014 | Loging Electronics
i must decide what to do so i can order the parts from the shop in my city because most of the ones I need are not in stock.
another thing i will solder the wires on the speakers because the connectors are very sturdy and put more wood glue inside the speaker corners. One of the speakers on certain frequency you can hear the wood oscillateing.
These values aren't very critical. If you are keeping the fuse, use 22R 7W shunt on the tweeter. I really just pulled 15R out of the air the other day. Then 4.7uF and 0.2mH (or 0.22mH). The fuse also helps keep impedance up, which is safer for the amp.
2R or 2.2R will make no difference either. I am assuming a regular 8 ohm tweeter with a DCR around 5-6 ohms. A 4 ohm (DCR around 3 ohms) tweeter is a slightly different animal, but should be fine with 4.7uF and 0.2mH anyway.
Rattles can be caused by loose connections and soldering, as well as obvious cabinet cracks. But some PVA wood glue will do no harm.
Changing the bass filter's shunt capacitance won't actually change the bottom end. Just the midrange level.
2R or 2.2R will make no difference either. I am assuming a regular 8 ohm tweeter with a DCR around 5-6 ohms. A 4 ohm (DCR around 3 ohms) tweeter is a slightly different animal, but should be fine with 4.7uF and 0.2mH anyway.
Rattles can be caused by loose connections and soldering, as well as obvious cabinet cracks. But some PVA wood glue will do no harm.
Changing the bass filter's shunt capacitance won't actually change the bottom end. Just the midrange level.
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Ok thanks i will order the 4.7uf and 0.2mH.
I got confused about the 2R or 2.2R. Should I add a resistor in series with the tweeter because of the 4.7uf? Since im keeping the fuse there is no need for an extra resistor or? the ptc fuse has 1.8ohm (by specification).
For the shunt resistor they only have MOX 10ohm 10W quality resistors so i will have to put 2 in series.
I got confused about the 2R or 2.2R. Should I add a resistor in series with the tweeter because of the 4.7uf? Since im keeping the fuse there is no need for an extra resistor or? the ptc fuse has 1.8ohm (by specification).
For the shunt resistor they only have MOX 10ohm 10W quality resistors so i will have to put 2 in series.
The resistor of 2R was for when you wanted to lose the fuse. You told me it was 2R resistance in normal operation.
What I'm trying to convey is that exact values and boutique parts aren't that critical. But you should still have a listen and adjust as necessary. 10% tolerance is near enough.
Most manufacturers would use a 3W wirewound 2.2R in this position. A 8 ohm tweeter is unlikely to exceed 10W in practise. So the shunt 22R will only see about 3W in practise too.
What I'm trying to convey is that exact values and boutique parts aren't that critical. But you should still have a listen and adjust as necessary. 10% tolerance is near enough.
Most manufacturers would use a 3W wirewound 2.2R in this position. A 8 ohm tweeter is unlikely to exceed 10W in practise. So the shunt 22R will only see about 3W in practise too.
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