Sony ta1130 underpowering Kef IMF

[The Jam]

4 hours ago, Fenda said:

Can you move the passive radiator to the back and the woofer to the front?

I think its acting to accentuate the mids, not as a woofer, I could be wrong (I'm not good at electronics theory, schematics etc)

[The Hurting]

If anyone is able to throw a bone on whether this x-over is acceptable, or if I it just needs a re-cap, or not to bother because the x-over will not be accurate, please feel free to share. Thanks. Even though I prefer the sound without the rear facing speakers I will replace them if it makes the existing x-over easier to alter.

[Cloth Ears]

On 13/05/2023 at 12:10 PM, The Jam said:

I think its acting to accentuate the mids, not as a woofer, I could be wrong (I'm not good at electronics theory, schematics etc)

A PR is used as a 'replacement' for a port - allows for a little more control of the resonance. So it really shouldn't be acting to accentuate the mids unless it's the result of the loss of the second woofer.

 

1 hour ago, The Hurting said:

If anyone is able to throw a bone on whether this x-over is acceptable, or if I it just needs a re-cap, or not to bother because the x-over will not be accurate, please feel free to share. Thanks. Even though I prefer the sound without the rear facing speakers I will replace them if it makes the existing x-over easier to alter.

The only reason you would want to put the rear speakers back is if there isn't another option. It looks like you cannot fit the 4 drivers (and the passive radiator) on the front panel - even if you create a new one to replace the current one. I'd say the rear one is not good where you currently have your speaker positioned. But, I'd be hesitant in recommending you update any components in the crossover unless you (or someone else) knows exactly what it's doing.

 

What to do?

 

You could try this, or you could move the PR to the side of the enclosure (allowing two drivers to the front). Either way you would need a new front panel, probably made with 18mm particle board and painted black.

[The Hurting]

Love your new design,

I was just going to put the rear facing drivers back in and replace the capacitors with the same values and hope that replacing the old caps might stop the clipping.

According to a previous post, moving all the drivers about requires a change in x-over design.

[andyr]

1 hour ago, The Hurting said:

Love your new design,

I was just going to put the rear facing drivers back in and replace the capacitors with the same values and hope that replacing the old caps might stop the clipping.

According to a previous post, moving all the drivers about requires a change in x-over design.

 

No "moving drivers around" will not affect the XO.  Only leaving out one driver will affect the working of the XO.

 

[The Hurting]

1 hour ago, andyr said:

 

No "moving drivers around" will not affect the XO.  Only leaving out one driver will affect the working of the XO.

 

 

Stereo Coffee original reply to my post was this link...

 

http://www.troelsgravesen.dk/crossovers.htm

"If you change front panel dimensions, actual drivers, placement of drivers and cabinet tilt in the constructions shown on these pages, you need a new crossover, and I can't help. The crossover will no longer work as intended, so please do not ask because I would need your speakers in my workshop to adjust the crossover.
Same thing if you want to use another tweeter, which is the question I most often have. Each tweeter needs its own individual crossover designed and fine-tuned for its particular response, phase and impedance for proper integration with the neighboring midrange driver."  http://www.troelsgravesen.dk/crossovers.htm

[The Hurting]

So it seems my post is dry and I am left alone with my ignorance and now non functioning speakers.

I have been offered differing opinions  so am at a loss.

Contrary opinions seem unwanting to converse.

 

andyr  contributes his opinion...   No "moving drivers around" will not affect the XO.  Only leaving out one driver will affect the working of the XO.

 

stereo coffee contributes his opinion... "If you change front panel dimensions, actual drivers, placement of drivers and cabinet tilt in the constructions shown on these pages, you need a new crossover, and I can't help. The crossover will no longer work as intended, so please do not ask because I would need your speakers in my workshop to adjust the crossover.
Same thing if you want to use another tweeter, which is the question I most often have. Each tweeter needs its own individual crossover designed and fine-tuned for its particular response, phase and impedance for proper integration with the neighboring midrange driver." http://www.troelsgravesen.dk/crossovers.htm

 

I am more confused than when I began, I was just going to recap them.

To be clear, these speakers are clipping hard and sound lack luster. I just want to know if I should bother re-capping, is that likely to be the issue? or is the x-over wrong to begin with and it cant be remedied and I should sell the parts?. Thank you.

 

Edited May 21, 2023 by The Hurting

[andyr]

Given the diametrically opposed responses you have got, @The Hurting, I'm inclined to suggest that:

1. spending money to replace the caps in the XO will not solve your problem.
2. even more so, if one of the drivers is defunct - and you don't replace it.
3. so ... getting some new spkrs - that are working! - is the only way you can graduate to good listening.

 

[The Hurting]

2 minutes ago, andyr said:

Given the diametrically opposed responses you have got, @The Hurting, I'm inclined to suggest that:

1. spending money to replace the caps in the XO will not solve your problem.
2. even more so, if one of the drivers is defunct - and you don't replace it.
3. so ... getting some new spkrs - that are working! - is the only way you can graduate to good listening.

 

Thank you, 

I don't feel there is anything defunct with any of the drivers, levels are even, no rubbing on VC, have an old proton that does not make the speakers clip, but they sound boring together..

It just seems the Kefs and the Sony are not getting along.

Thank you. I will sadly part these out and seek more compatible speakers.

[Fenda]

Go to a speaker repairer and get them to sort them out, might be cheaper than buying new speakers

[andyr]

13 hours ago, The Hurting said:

have an old proton that does not make the speakers clip, but they sound boring together..

It just seems the Kefs and the Sony are not getting along.

Thank you. I will sadly part these out and seek more compatible speakers.

 

The fault (in terms of 'boring') may well be that the KEF IMFs simply need a lot more power than your Proton or Sony have to offer, to sound good?

 

As you're in Melbourne, I could bring over a pair of 100w AKSA 'Soraya' monoblocs that I have spare - just to see if they make your spkrs sound good.  I believe your Sony TA1130 has 'pre outs' - which can feed the monoblocs?

 

The Sorayas used to drive my 4 ohm Maggie bass panels; I strongly suspect your spkrs are actually nearer 4 ohms than 8 ohms - the Sorayas can put out 180w into 4 ohms ... so they should drive them quite well.  If they do ... then a 200w AKSA amp would probably make them sound even better!  

 

PM me if you're interested.

 

[Cloth Ears]

On 21/05/2023 at 10:02 PM, The Hurting said:

Thank you, 

I don't feel there is anything defunct with any of the drivers, levels are even, no rubbing on VC, have an old proton that does not make the speakers clip, but they sound boring together..

It just seems the Kefs and the Sony are not getting along.

Thank you. I will sadly part these out and seek more compatible speakers.

Chris, I'd take up Andy's offer in a heartbeat. Hugh's amplifiers are pretty good and should show you if your speakers are worth saving (if the drivers all work, they should be).

[The Hurting]

 

These are the film caps from the tweeter, I wanted to replace them, I presumed they were 4.7uf until I took them out. One says 47uf, the other .47uf? 

I presume they are not large enough to be 40 year old 47uf film capacitors.

I cant imagine a tweeter like this would only have just  .47uf?

I have replaced them with the 4.7uf I purchased but I'm worried I might blow the tweeter.

I dont understand the theory at all, I'm just chopping in and out, I know the frequency changes with the value, I dont want my tweeter to over extend, should I replace with .47uf (they sound not much different with the new caps, just better imaging)

 

[The Hurting]

I managed to fit all the speakers in a baffle on the front (still not sure why that active speaker would be rear facing) then recapped the messy crossover (it's still messy just recapped) then filled with sheepskin fleece and they sound great. Next is to refinish the cabinets and grills. I think they may be worthy of better designed x-overs... I have a ton to learn.

[Cloth Ears]

On 25/05/2024 at 10:09 PM, The Hurting said:

I managed to fit all the speakers in a baffle on the front (still not sure why that active speaker would be rear facing) then recapped the messy crossover (it's still messy just recapped) then filled with sheepskin fleece and they sound great. Next is to refinish the cabinets and grills. I think they may be worthy of better designed x-overs... I have a ton to learn.

They look good and it's excellent that they sound great.

The idea behind having two speakers facing from and rear would be an attempt to have a more spacious soundstage...but without doing the same to the midrange and the tweeter, it does seem a bit half-arsed.

Did you end up borrowing @andyr's amps at all? That might give you ideas after you've finished the finish on you new speakers.

[99 .]

I would have put the midrange dome and tweeter closer together.

 

Good to have both bass units, as you increase power handling.

 

When removing one bass driver, you may also decrease power handling by a big margin because now the passive radiator is out of tune with the single bass driver, potentially causing more excursion and decreasing power handling by more than 50% 

[The Hurting]

1 hour ago, 99 . said:

" would have put the midrange dome and tweeter closer together."

Thank you.

I was told to put the tweeter on the outside for soundstage.

I read up on your suggestion and it seems the mid and tweeter should be either closer than 2 inches or further than 7inches. 

I think I will leave the tweeters on the outside and place the mid right in the middle. 

I did what I did for aesthetics without thinking or researching.

So thanks.

Back to making baffles. (will it improve soundstage or???)

[99 .]

1 hour ago, The Hurting said:

Thank you.

I was told to put the tweeter on the outside for soundstage.

I read up on your suggestion and it seems the mid and tweeter should be either closer than 2 inches or further than 7inches. 

I think I will leave the tweeters on the outside and place the mid right in the middle. 

I did what I did for aesthetics without thinking or researching.

So thanks.

Back to making baffles. (will it improve soundstage or???)

It should improve driver integration, which in turn should improve soundstage.

Ideally you'd have the drivers vertically aligned but it seems like you have run out of space on the baffle

Older speakers used to have them horizontal, even this one, but close together except for some few odd ones.

 

You could have the bass units way over to one side leaving room for the mid and tweeter to be vertical. But it would be tight, might look weird. Don't forget to mirror the left and right speaker