It can be useful to measure the old one, then the new one. Do this straight away without moving the mic or anything else. Once you have this comparative information you can simulate the two simultaneously and adjust the crossover, the level padding and account for any tilt or resonances.
Please bear with me with this one 😬!
My Jamo 7.6 speakers which I have had the pleasure of owning since new and are now 22 year plus old in near mint condition.
These being same as Jamo D570 and similar to others inc 7.7 and D590.
Crossovers look identical to D570 and D590 but slightly diff to other Jamo models with the twin bass units in.
I have sympathetically upgraded the crossover capacitors with like for like uf mainly Clarity Caps ESA and also R1 inline tweeter resistor with Mundorf MREC10-2.2: 2R2 Mundorf M-Resist 10W Classic Resistor (2.2R). These were done approx 2 years ago and all good.
However over time and with the age of these speakers now this week I decided to change the tweeter units (as I think ferro fluid has dried out in these over time) to Scanspeak D2905/950000 Tweeter - Classic Range × 2 (being recommended ). These were a perfect fit as you can see above in my previous post.
These sound very nice compared to the original however they are 6 ohm tweets and I wasn't sure what the original ones were (but original Jamo 38819 tested 6.2 ohms Dc) as not stamped on tweet.
The sound at present is confusing me slightly as I am wondering if the new tweets @ 6ohm have changed or moved my crossover point as it seems I now have lots more Bass and mids also sound different (can't really explain).
Would appreciate a little guidance if possible. I am able to change capacitor values and or resistors in my crossover but I don't have any test equipment other than a capacitor tester and small handheld ohm resistance tester.
My thought are maybe I should change resistor value ( currently 2.2 ohms )and or capacitor uf on tweeter side as replacement tweets now 6 Ohms but I'm not sure and your thoughts would be very much appreciated .Find attached schematic of my crossover.
thank you all look forward to your thoughts.
Regards Adi
My Jamo 7.6 speakers which I have had the pleasure of owning since new and are now 22 year plus old in near mint condition.
These being same as Jamo D570 and similar to others inc 7.7 and D590.
Crossovers look identical to D570 and D590 but slightly diff to other Jamo models with the twin bass units in.
I have sympathetically upgraded the crossover capacitors with like for like uf mainly Clarity Caps ESA and also R1 inline tweeter resistor with Mundorf MREC10-2.2: 2R2 Mundorf M-Resist 10W Classic Resistor (2.2R). These were done approx 2 years ago and all good.
However over time and with the age of these speakers now this week I decided to change the tweeter units (as I think ferro fluid has dried out in these over time) to Scanspeak D2905/950000 Tweeter - Classic Range × 2 (being recommended ). These were a perfect fit as you can see above in my previous post.
These sound very nice compared to the original however they are 6 ohm tweets and I wasn't sure what the original ones were (but original Jamo 38819 tested 6.2 ohms Dc) as not stamped on tweet.
The sound at present is confusing me slightly as I am wondering if the new tweets @ 6ohm have changed or moved my crossover point as it seems I now have lots more Bass and mids also sound different (can't really explain).
Would appreciate a little guidance if possible. I am able to change capacitor values and or resistors in my crossover but I don't have any test equipment other than a capacitor tester and small handheld ohm resistance tester.
My thought are maybe I should change resistor value ( currently 2.2 ohms )and or capacitor uf on tweeter side as replacement tweets now 6 Ohms but I'm not sure and your thoughts would be very much appreciated .Find attached schematic of my crossover.
thank you all look forward to your thoughts.
Regards Adi
Attachments
Thank you Allen for your thoughts. Will give it a go tomorrow . My only concern is will removing the 2.2 ohm resistor @ R1 on the tweeter affect the overall resistance of the speakers and drop , as I believe these Jamos can drop at certain frequencies to around 2 ohms overall . Many thanks.
Good morning AllenB .
I have removed the 2.2ohm resisters and replaced with cable. Much much better but way too bright. I’m a bit stuck now with choice of replacement resister as it obviously needs something in there 😵💫 any thought on value would be much appreciated .. any thoughts on poss a 1 ohm or should I go lower or higher .apologise for being a pain.
I have removed the 2.2ohm resisters and replaced with cable. Much much better but way too bright. I’m a bit stuck now with choice of replacement resister as it obviously needs something in there 😵💫 any thought on value would be much appreciated .. any thoughts on poss a 1 ohm or should I go lower or higher .apologise for being a pain.
What I usually (would) do is not remove the 2.2, just put the cable across it. Then, I'd try other resistors across it. Try another 2.2 = 1.1 total.. if not, try again larger or smaller.
It's OK that you've removed it now. I can't suggest a value, you have to do that. Maybe 1 ohm, 0.5 ohm..?
It's OK that you've removed it now. I can't suggest a value, you have to do that. Maybe 1 ohm, 0.5 ohm..?
Hi all.
Just thought I,d give a quick update to the replacement tweets to Scanspeak D2905/950000 Tweeter in my Jamo 7.6 . After a week or so the tweet has opened up nicely, very airy nice soft but clear sound now I have settled on a pair of 1.5ohm mills MRA12 resistors for the tweets. This could however be dropped IMO to somewhere in the region of 1 to 1.2 ohms if you prefer more tweet detail, however I prefer personally at 1.5ohms.
Many thanks to AllenB for your help.
Just thought I,d give a quick update to the replacement tweets to Scanspeak D2905/950000 Tweeter in my Jamo 7.6 . After a week or so the tweet has opened up nicely, very airy nice soft but clear sound now I have settled on a pair of 1.5ohm mills MRA12 resistors for the tweets. This could however be dropped IMO to somewhere in the region of 1 to 1.2 ohms if you prefer more tweet detail, however I prefer personally at 1.5ohms.
Many thanks to AllenB for your help.