No more bass with my new caps on 43xx clone

[gerard]

Hello

I need some help ...

I change my caps on my crossover on my 43xx clone .
My crossover is much simple than the original one and was 30 years old ....

first I change the Hf and uhf caps for the same value using Dayton and Dayton by pass for 2420 and dayton and audiocap as by pass .
result was very good with a lot of difference in Imaging , stereo etc ...

Some friends told me it was no use to change the 56uf caps for medium and bas but I decide to do so and I exchange 2x56 uf on each xover with Solen .

result were very enthousiastic , the medium was very present and did recover the sound of trumpet and sax I lost for some years ...
Also the left bass speaker (le15a) was sounding like it need recone before changing the caps and when I change to solen caps it sounds good without resonance !!!!!!

Now the problem is :

I feel I loose my bass under 180 /120 hz and can't explain why .
Everything works ok , medium is ok , the bass speaker are " moving " I do not know the right word in english when there is bass sound music .
The left spaker when using a test Cd seems to not giving sound between 75 and 60 hz !!!

I can't explain this and Did not change anything else !
Could this mean my amp does not like the new caps ? or anything else .

Help should be appreciated .


Gerard

[4313B]

Do you have a schematic of your filter? Sounds like something got wired up wrong. You did nothing else but replace caps value for value right? Got the polarity on all the drivers right?

[gerard]

Giskard


thank you for your answer ; I only change 56uf old caps by new and re solder .

both xover works the same , the le15a is working but I would say the 800 hz medium is much better and the 120-200 hz bass is lower !!!

I have no schematic .

I replace back black and red connection on the le15a as before ...

gerard

[Earl K]

Now the problem is :

I feel I loose my bass under 180 /120 hz and can't explain why .
Everything works ok , medium is ok , the bass speaker are " moving " I do not know the right word in english when there is bass sound music .
The left spaker when using a test Cd seems to not giving sound between 75 and 60 hz !!!

I can't explain this and Did not change anything else !
Could this mean my amp does not like the new caps ? or anything else .

Help should be appreciated .

Hmmmmm,

A few thoughts ,

- Really, any 434x " 4-way clone", IMHO should be using a woofer that has a heavier cone than what the le15 offers. This is just so that the woofers' "mms" value or weight / or bass making authority / can be correctly balanced against the overall "perception" of UHF "quantity". This is a JBL "voicing" or design- directive that your 4-way clone ignores.

- Your modifications & upgrades with capacitors have no doubt released & uncovered lots of resolution in the midrange to uhf areas. This is likely signal content that your never knew you had in your system. In my experience, this increase in resolution is just like turning up the volume knob for those specific frequency areas .

- So, in my mind all these modifications are great , except they make the bass portion of your clone setup appear to be "wanting" or bass-shy. Again, this is because "perceptually" you've turned-up the volume for the rest of the system .


- That's the best I can surmise from this vantage point ( excluding the possibility of some incorrect wiring ).

- Worth noting ; DC biasing the HF or UHF areas (IME) can be just like turning down the volume knob for the area just biased . I figure this is because the removal of signature resonances from the respective capacitors is perceived by the ears, as an actual reduction in overall HF or UHF volume. :blink:

<. EarlK :cheers:

ps ; I'd start thinking about some woofers with an MMS value of around 150 grams ( &/or at least DC bias all your top-end networks ). These changes will rebalance your systems' overall voicing / hopefully in a direction that you need . :o:

Oh,, and a belated :birthday: ( I see that next year is the big Five O. It all gets better after that point ;) )

- Another thought,, everything I've mentoned so far might be exacerbating an existing mismatch in your choice of LF driver & Network component values. So, just what are the inductor & capacitor values for the LF leg of your "simplified" network ?

[gerard]

THANK YOU Earl K


I will open my system this week end , something must go wrong like a mismatch , i will check again the wiring and come back .it seems like having a filter from 240 hz to 0 !!!!

regards

Gerard

[Earl K]

Okay Gerard, I'm on a golfing getaway till next Tues. :D

[gerard]

:banghead: I am really lost on that Xover .

First pic 159l ( see circle in black at the end of a black line , on the upper left side ) is my Xover with old 56uf caps .
I change the caps ( see image 211l ,) and only did not add the wire between the 2 caps as I was able to soldier the 2 end of the caps together .

No bass or very limited !!!!

Then I went back to the Xover and add a wire ( black) between the 2 caps .

Bass is back !!!! , may be not as before with the old cap but cleaner and firmer .

Does someone understand ?

regards

Gerard

[Zilch]

Dunno. Your original connection of the two capacitors may have been marginal. I don't see any overlap or twisting together of the capacitor leads there, and the single-point solder connection didn't look very good.

In the final connection, you soldered pretty close to the capacitor there. I wouldn't have done that without a heat-sink on the lead between the connection and the capacitor.

If it's working now, it's likely fine, tho.... :)

[gerard]

Zilch
I ahve to learn a lot , but I did not feel to make a compete new crossover and I had to work on the one I had .

I just can(t explain this difference !

Gerard