Concertino - Upgrading caps and other mods

[spammoj]

Hi all, 

 

I have a pair of SF Concertinos that I like very much, and aesthetically they are my wife's favourite speakers too. While they sound nice and laid back, I am also left wanting in terms of separation and detail in the top end. Just for a bit of fun I am thinking of upgrading the caps and internal wiring to squeeze some life out of these. 

 

Not sure where to start as I have very little electrical knowledge and this will be my first attempt at tinkering with crossovers. I've read that just upgrading the caps and internal wiring can yield some (subjective) benefit so I'd like to try this. If anyone has any suggestions on what to tackle first or any other ideas to hot rod the Concertinos please chime in. I'm thinking extra acoustic filling, upgraded caps and wiring to start with. 

 

Here are some pics of the inside. Not sure what the goopy black stuff is but managed to peel some away to reveal some of the values. I may have to remove all of the black stuff to figure out component values. Do I buy a multimeter for this if the values aren't printed? 

[Peter_F]

40 minutes ago, spamnoj said:

While they sound nice and laid back, I am also left wanting in terms of separation and detail in the top end.

Have you eliminated the amp and/or source as the problem?

[Guest Muon N']

That smaller square blue cap between the two resistors may be the one on the tweeter side of things, but would help if have the schematic.

[Wozza_Lee]

Get yourself a minidsp and cut out the xo all together. Run them off a the minidsp and duel amps.

Then you will get the absolute best performance possible out of the driver's that you already have.

Also gives you the possibility of running peq and all sorts of tinkering for hours and hours of joy.


My $0.02

[spammoj]

13 minutes ago, Peter_F said:

Have you eliminated the amp and/or source as the problem?

Yes, sounds terrific with other speakers I have.

 

12 minutes ago, Muon N' said:

That smaller square blue cap between the two resistors may be the one on the tweeter side of things, but would help if have the schematic.

May have to pull the whole thing out and map it as I don't think SF circuits will be readily available.

 

3 minutes ago, Wozza_Lee said:

Get yourself a minidsp and cut out the xo all together. Run them off a the minidsp and duel amps.

Then you will get the absolute best performance possible out of the driver's that you already have.

Also gives you the possibility of running peq and all sorts of tinkering for hours and hours of joy.


My $0.02

Not a bad idea, already have some minidsps kicking around in the cupboard unused. Haven't tried doing that before but will explore this as an option. Any good resources on how to learn to do this? I will jump on youtube and google tonight

[Wozza_Lee]

Minidsp forums is great. Also the website has great how to's and reading material

[spammoj]

Will try have a tinker with minidsp sometime. 

 

In the mean time will adding extra stuffing to the cabinets help? I'm surprised that there was minimal stuffing on the inside. 

[davewantsmoore]

3 hours ago, Wozza_Lee said:

Get yourself a minidsp and cut out the xo all together. Run them off a the minidsp and duel amps.

Then you will get the absolute best performance possible out of the driver's that you already have.

ONLY if he is able to create a XO/EQ in the minidsp which is as good or better as the passive circuit he is replacing.

 

ie. it's almost certain it would have worse performance, if he's never designed a speaker/baffle step/XO before.

Edited November 8, 2019 by davewantsmoore

[Guest Muon N']

35 minutes ago, spamnoj said:

Will try have a tinker with minidsp sometime. 

 

In the mean time will adding extra stuffing to the cabinets help? I'm surprised that there was minimal stuffing on the inside. 

experiment with sound absorbing filler, more is not always better and can suck the life out if too much is used. Do it so there is some absorbing but also breaking up sound waves inside the cabinet.

 

But I'm very much a novice in this area.

[spammoj]

58 minutes ago, davewantsmoore said:

ONLY if he is able to create a XO/EQ in the minidsp which is as good or better as the passive circuit he is replacing.

 

ie. it's almost certain it would have worse performance, if he's never designed a speaker/baffle step/XO before.

Thanks for the sense check! I suppose playing with an active xo is a cheap and non destructive way to see if I like the results. Would you still advocate replacing like for like components on the passive xo with higher quality bits? 

[Decky]

There are several ways how you could improve that xover BUT your biggest enemy is the lack of space. Your current caps are decent (polyester film or MKT) - if you replace them with polypropylene film ones (MKP) you will need 4 times more space. The same thing is with that iron core inductor - the size of a equivalent replacement air core or copper film inductor will be roughly 4 times the size. 

 

I used to do these conversions in the past but the only way for them to succeed is to built an external xover box and save the original xovers in case you want to sell the speakers in the original form.   

 

The first step is to reverse engineer the xover and measure the components with a good LCR meter. The job is not complicated but it does require some careful planning and strategic thinking. Finally the cost of the replacement parts can go up to $500 if you want some decent mid to high end components (exotics not included).   

[davewantsmoore]

9 hours ago, spamnoj said:

Thanks for the sense check! I suppose playing with an active xo is a cheap and non destructive way to see if I like the results.

Absolutely.

The paradox with doing this is that if you make a XO/filter which sounds very _different_ to the existing speaker (but perhaps more "wrong") it can sound "better" .... but that's cool, there's no accounting for taste, so have fun.

 

9 hours ago, spamnoj said:

Would you still advocate replacing like for like components on the passive xo with higher quality bits? 

Tough question, at the risk of sounding out of touch with what you will read of peoples experiences, I would lean towards no.

 

Consider that parts tolerance when extremely close are in the order of many %...  Depending on the design of the filters, this can make quite a difference to the response  (ie. from different parts values, not different parts "quality").

 

I design main "active" crossovers, due in part to that issue.  Matching of parts values.... and that "agreed good sounding" (by the audiophile market) parts are quite expensive.

[Guest Muon N']

Re-build them on boards of an appropriate size, install through the cutout of mid woofer.

[afa]

Hi,

It is possible that the ferrofluid in the seas 19TFFF has dried up a little (the tweeter is over 20 years old, ie 46/98 = week/year) possibly causing a drop in sound output,

Any chance of posting a frequency plot on tweeter axis? if you dont have any measuring gear, you can download audio tools (https://play.google.com/store/apps/details?id=com.julian.apps.AudioTool&hl=en_AU ) for your smartphone and then  use pink noise as a signal, point your phone mic at the tweeter (say about a meter away) and use 1/12th octave filtering, and then post your result.

This measuring method is far from ideal but at least we can then get a bit of an idea what might be the "problem"

cheers, Arthur