3 way upgrading Jamo D590 replacements and filter question

Thanks John.

For following observations just note that driver specs are frd and zma files for your drivers, that's all I have.

R1 and 72//4,7 uF removed:
System response is fairly flat, with -5 dB dip between 3-4 kHz (3 kHz original crossover frequency), due to a poor matching of tweeter and mid sections at that interval. Spent hours trying to "lift" mid section around crossover point, without success. The dip is there whatever I try.

A few things I don't understand:
  • Bass response. I used frd and zma for SLS 830667 provided in this thread.
  • Mids response. Used 5FE120_8 No xover mid 90dB at 1K 1_6 smooting_SPL.frd and New 5FE120_8_ZR.zma
Are these not the correct ones?

Not to mention impedance response????
 

Attachments

  • 707a no tweeter resistor.png
    707a no tweeter resistor.png
    42.4 KB · Views: 63
Thanks John.

For following observations just note that driver specs are frd and zma files for your drivers, that's all I have.

R1 and 72//4,7 uF removed:
System response is fairly flat, with -5 dB dip between 3-4 kHz (3 kHz original crossover frequency), due to a poor matching of tweeter and mid sections at that interval. Spent hours trying to "lift" mid section around crossover point, without success. The dip is there whatever I try.

Hello pelleplutt

Nice to se that you begain with XSIM :)....It´s fun to expriment.

First of all, you have connected your 2 woofers wrong in the sheme.
I had to go in serie from + to - to + to - .......Now you have both in parallel from + to -

Also the Peerlees SLS woofer is 8 ohm and when connected like you scheme it is 4 ohm, Jamo original is 4 ohm and with connetion in serie it gets 8 ohm in total.

I try to start my XSIM for Jamo 707 xover, but get an ERROR.....Will try later.

PS ! You can keep you 4,7 uF Clarity cap
 

Attachments

  • woofers in serie.png
    woofers in serie.png
    15.8 KB · Views: 34
Hello John, are you sure 707a original woofers are 4 ohm each? I haven't seen any push-pull woofers in series on the different 707 in this thread, maybe I missed it.
I will have a look inside the box tomorrow.


Have look for answer, and maby both of us i right.
It seems to be 8 ohm woofers, but connected in - and + trought them.

Read Moorclos post
And maby my post



1679012527991.png



1679012632396.png


Regards John in the middle of the night
 
John,

Hope I'm not the reason for you staying up in the middle of the night?! :confused:

Yesterday I pulled out the woofers, checked all wirings to PCB and as Jamo's print on component side shows, at least mine are in parallell. PCB is also exactly as Moorclos'. Connecting them in series should mean a time delay between them (maybe not audiable) but four times higher impedance (16 instead of 4 ohm).

Also changed R1 from 4,7 to to 2 ohm (4,7//3,3 = 1,93875 ohm). No significant difference in sound, maybe a slightly raised treble (should be). Will give it some time to evaluate.

Now I'm planning for moving xover outside of box and rearranging components. Especially coils, they should not be mounted like that. Moving it outside makes it easier changing components. Here's a video on this forum about coils.
Try to rotate axis of one inductor orthogonal to the other so that they don’t cross couple. Distance helps but it is surprising how audible the cross coupling can be when axis are parallel. You have all 4 parallel here.

Here is a video I made of air core inductor cross talk. One XO board transmitting sound to another XO board that is not connected to an amp.


Attaching a few images. The "feet" are youghurt caps, filled with professional clay (acoustically "dead"). Speakers are mounted with spikes going through rubber feet and into the clay. Speakers stand in a box of corrugated cardboard with a layer of foam rubber in the bottom. Just to be able to move them around the room smoothly when listening seriously.
Don't tell anyone, men in long white coats might come and pick me up.

Saturday again! 🍷
 

Attachments

  • youghurt feet.jpg
    youghurt feet.jpg
    359.7 KB · Views: 66
  • inverted woofer.jpg
    inverted woofer.jpg
    330.3 KB · Views: 69
  • bitumen walls.jpg
    bitumen walls.jpg
    191.1 KB · Views: 70
Attaching a few images. The "feet" are youghurt caps, filled with professional clay (acoustically "dead"). Speakers are mounted with spikes going through rubber feet and into the clay. Speakers stand in a box of corrugated cardboard with a layer of foam rubber in the bottom. Just to be able to move them around the room smoothly when listening seriously.
Don't tell anyone, men in long white coats might come and pick me up.

Saturday again! 🍷

Hahaha youghurt caps, yes maby men i long white rocks come and pick you up ;)

I have never built a xover that connects the woofer that way, so im not the right one to answer how it "supouse to be connected"
And diden´t know you still use "the same" word for that connection....i.e "paralell"

Here is some reading for you pelleplutt, it explains Isobaric subwoofer box design.

https://audiojudgement.com/isobaric-subwoofer-box-design/

Also changed R1 from 4,7 to to 2 ohm (4,7//3,3 = 1,93875 ohm). No significant difference in sound, maybe a slightly raised treble (should be). Will give it some time to evaluate.

Maby try out without resistor at all ?

Saturday again! :cheers:
Regards John
 
Thanks John for interesting link!

Since there are a few more testings with different component values I'd like to do I will focus on moving xo out of box.
Soldering is not funny, I'm not good at it, and my soldering station is probably not the best, I will start with connecting components through terminal blocks. If ever happy, I will solder.
 
  • Like
Reactions: 1 user
Ok now are the new Scan speak tweeters installed and tested and i think they are perfect for this project! The sound right now is wide open and clean,maybe it can be to much in some songs but i think that is a ok tradeoff
 

Attachments

  • 08234931-D110-4612-B93A-61BFDE991BC1.jpeg
    08234931-D110-4612-B93A-61BFDE991BC1.jpeg
    331.6 KB · Views: 76
  • Like
Reactions: 1 users
Congrats Belemakare, good you've come so far. Also good this thread is still alive.

As for the new domes, give them some time. As with all new components there is a burn-in time. My Clarity caps took at least 200 hours before a certain dull sound gave away. Whether it's a change in the components or in the ears/brain is hard to say, maybe a combination.
 
  • Like
Reactions: 1 user
Ok so its where the pipe is paralell that you measure the lenght?

I really like the 83000,crisp clean and sounds more natural than the sb tweeters in me ears and the higher sensitivity made a nice final touch
I will not do anything more with the mids/tweeters (I think..)😉
 
  • Like
Reactions: 1 user
Hi been reading this post and you guys have done some real in depth mods to various models of Jamo,s. Please could anyone help regarding Jamo 7.6 as I have replaced the original tweeters with a pair of

Scanspeak D2905/950000 Tweeter - Classic Range × 2
Has anyone any suggestions on capacitor change and or resistor value Change just for the tweeters circuit . Many thanks in advance for any help.
Below is crossover for 7.6
 

Attachments

  • IMG_5952.jpeg
    IMG_5952.jpeg
    245.7 KB · Views: 50
  • IMG_6982.jpeg
    IMG_6982.jpeg
    388.1 KB · Views: 56