Sony ta1130 underpowering Kef IMF

[The Hurting]

So this combination is new to me.

I had the sony ta1130 with polk monitor 10 and it was magic.

The sony at 45wpc was as powerful as my Sansui 8080db 80wpc.

I've had similiar Kef IMF speakers and never been happy. These ones look home made and have an identical mid driver facing the rear, which I removed and then sealed the cab because in my small living room it sounded horrid, I didnt alter the x-cover, I just snipped speakers and sealed cabinet.

The Sony doesn't seem powerful enough to drive these speakers  which seems odd, it is powerful beyond its 45wpc, when I turn the volume up the speakers wobble and over extend (clipping?) and make frightening snapping sound.

But I know the amp sounds wonderful, I'm sure the tweeters and mids of the speakers would sound wonderful. 

Is there a way to make the amp and speakers compatible?

I really look forward to replies. Thanks.

 

 

Edited May 10, 2023 by The Hurting
bad grammar

[muon*]

I would have replaced those gray coloured electrolytic caps, they are very old and likely out of spec.

[stereo coffee]

It would appear there is no following of a crossover schematic , rather a layout that is " let's see what happens" . This might give you some ideas

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

[The Jam]

1 hour ago, stereo coffee said:

It would appear there is no following of a crossover schematic , rather a layout that is " let's see what happens" . This might give you some ideas

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

 

Thanks Stereo Coffee. The person who made these spent a lot of money on expensive tweeters and drivers and rear facing driver and well made cabinet, why would he not have followed a design from a magazine etc?

What makes you think it is just a layout he took a stab at instead of a schematic from a design?

I'm not saying you are wrong, I'd just prefer you where because the article you forwarded very clearly tells me that if what you say is true, I may as well just part out these speakers, there is no way for me to design a x-over for the speakers and they will continue to clip hard.

[stereo coffee]

1 hour ago, The Jam said:

 

Thanks Stereo Coffee. The person who made these spent a lot of money on expensive tweeters and drivers and rear facing driver and well made cabinet, why would he not have followed a design from a magazine etc?

What makes you think it is just a layout he took a stab at instead of a schematic from a design?

I'm not saying you are wrong, I'd just prefer you where because the article you forwarded very clearly tells me that if what you say is true, I may as well just part out these speakers, there is no way for me to design a x-over for the speakers and they will continue to clip hard.

It is usual with a loudspeaker crossover to have a large inductor prior to the positive of the bass driver, and secondary a capacitor in parallel across the driver, although just the inductance of the coil winding  predominates, so the capacitor there can often not be used . From what i see there is no inductor prior to the bass driver you are using or the one that was disconnected.. leaving out that inductor creates a severe reactance for the amplifier to have to deal with- hence the noises you attribute.

 

firstly though you need at least 5 tag boards for each speaker , with at least three hookup points on each to tidy up the wiring - which is presently dreadful. If you want to not discard the speakers begin by drawing / taking images of each area. In the good images you have provided there are many spots where it is hard to say where the wiring is going, so clarify each area before tidying up. 

 

Arrange the wiring into at least 3 distinct areas , one tag board screwed down for each driver and a tag board each for positive as one and negative of the other. have these last two within reach of the drivers positive and negative wiring. 

 

The drivers you have are attempting to be similar ( but obviously not the same ) as a kef 104 ab , which as a beginning point the schematic of that will be very useful. I will hunt one down and re post.  

 

Post some images with progress and I, and no doubt other forum members will help  you.

 

 

Edited May 11, 2023 by stereo coffee

[walker1000]

I notice in your picture of the amp you have the bass control fully up, this could cause the bass driver to " wobble " and make snapping sounds as it bottoms out.

Maybe you are asking too much from these speakers in regard to bass output and high volume?

Also check the phase of the speakers if you find the bass output is weak by reversing the speaker connection from the amp to ONE speaker only and see if the bass improves, you shouldn't need the bass control at maximum for good sound assuming that is how you are using it.

Edited May 11, 2023 by walker1000
added more info

[The Jam]

32 minutes ago, stereo coffee said:

It is usual with a loudspeaker crossover to have a large inductor prior to the positive of the bass driver, and secondary a capacitor in parallel across the driver, although just the inductance of the coil winding  predominates, so the capacitor there can often not be used . From what i see there is no inductor prior to the bass driver you are using or the one that was disconnected.. leaving out that inductor creates a severe reactance for the amplifier to have to deal with- hence the noises you attribute.

 

firstly though you need at least 5 tag boards with at least three hookup points on each to tidy up the wiring - which is presently dreadful. If you want to not discard the speakers begin by drawing / taking images of each area. In the good images you have provided there are many spots where it is hard to say where the wiring is going, so clarify each area before tidying up. 

 

Arrange the wiring into at least 3 distinct areas , one tag board screwed down for each driver and a tag board each for positive as one and negative of the other. have these last two within reach of the drivers positive and negative wiring. 

 

Post some images with progress and I, and no doubt other forum members will help  you.

 

 

Thank you, I was about to pop down to Jaycar and get some tag boards, then I had another look at the x-overs. I can unsolder and solder, that is all I have ever done, I don't even understand why the dual tweeters are connected to the mid, or if its even a mid or acting as a bass driver, I don't even think I have the brains to tidy the rats nest.

This sentence already confused me  "... and a tag board each for positive as one and negative of the other. have these last two within reach of the drivers positive and negative wiring."

I will sadly sell the speakers for parts and try and find some professional speakers that suit the Sony.

Thank you for the offer, I would just be a pain. Thanks again.

[The Jam]

7 minutes ago, walker1000 said:

I notice in your picture of the amp you have the bass control fully up, this could cause the bass driver to " wobble " and make snapping sounds as it bottoms out.

Maybe you are asking too much from these speakers in regard to bass output and high volume?

Also check the phase of the speakers if you find the bass output is weak by reversing the speaker connection from the amp to ONE speaker only and see if the bass improves, you shouldn't need the bass control at maximum for good sound assuming that is how you are using it.

Thanks, The bass and loudness are up (not very hi-fi of me) but I was listening quietly to some Blossom Dearie not Fugazi loudly, so it wasn't pushing them too hard, but yes the bass seems very lacking, I know i have them connected correctly presuming the connections on the speakers are right. I will swap and check by ear and touch. Thanks

[stereo coffee]

But if you want to have a go, as they are nice drivers and the cabinet is good too, perhaps  you have someone to also help you ( other than us ) Further to my post , your drivers are three way, but not usual drivers to match to a Kef schematic which was effectively a 2 way design for the 104 ab , but similar to your drivers the 104 ab used a kef B200 and passive radiator.

 

As a beginning these two schematics will be useful.  You can reliably use the 104ab schematic for the woofer and tweeter values , as the tweeter you have is not dissimilar to the T27. It looks like a Celestion or Coles design . The inductor Kef used could be selected for any of three positions. With inductors in series the values are added, so choosing 5mh as its value would be close.

to  

 

The information here will be useful to accommodate the midrange driver. You will need to make the series capacitance slightly lower in value as it appears your midrange driver is smaller than any that Kef ever used  https://www.diyaudio.com/community/threads/kef-concerto-improved-dn12-crossover-with-full-ab-circuit.370666/

 

The Gale schematic below,  too is useful to see how a three way crossover works

 

 

Edited May 11, 2023 by stereo coffee

[Cloth Ears]

14 hours ago, The Hurting said:

So this combination is new to me.

I had the sony ta1130 with polk monitor 10 and it was magic.

The sony at 45wpc was as powerful as my Sansui 8080db 80wpc.

I've had similiar Kef IMF speakers and never been happy. These ones look home made and have an identical mid driver facing the rear, which I removed and then sealed the cab because in my small living room it sounded horrid, I didnt alter the x-cover, I just snipped speakers and sealed cabinet.

The Sony doesn't seem powerful enough to drive these speakers  which seems odd, it is powerful beyond its 45wpc, when I turn the volume up the speakers wobble and over extend (clipping?) and make frightening snapping sound.

But I know the amp sounds wonderful, I'm sure the tweeters and mids of the speakers would sound wonderful. 

Is there a way to make the amp and speakers compatible?

I really look forward to replies. Thanks.

 

 

OK.

 

So, you removed one of the mid-bass drivers without changing the crossover at all? This probably means that you've completely changed the crossover point. As the original would have been expecting either a 4 ohm load (of the drivers were in parallel) or a 16 ohm load (if they were in series).

 

It also means that the oval shaped passive radiator is not being driven properly as only half the amount of air is being moved inside the box.

 

It definitely looks like a home design, so making changes to it without knowing the original design could simply cause your amp to self destruct. As it is, with the amp being driven hard to run the now anemic bass, it's possible that the tweeter could be damaged if you get too much distortion from the amp as a result (always a danger when you run your amp too hard).

 

If you didn't like the driver on the back of the enclosure, might I suggest another option? Redesign the front of your enclosure to have both the mid-bass units on it (you could use the passive radiator on its side)...

[The Jam]

1 hour ago, stereo coffee said:

But if you want to have a go, as they are nice drivers and the cabinet is good too, perhaps  you have someone to also help you ( other than us ) Further to my post , your drivers are three way, but not usual drivers to match to a Kef schematic which was effectively a 2 way design for the 104 ab , but similar to your drivers the 104 ab used a kef B200 and passive radiator.

 

As a beginning these two schematics will be useful.  You can reliably use the 104ab schematic for the woofer and tweeter values , as the tweeter you have is not dissimilar to the T27. It looks like a Celestion or Coles design . The inductor Kef used could be selected for any of three positions. With inductors in series the values are added, so choosing 5mh as its value would be close.

to  

 

The information here will be useful to accommodate the midrange driver. You will need to make the series capacitance slightly lower in value as it appears your midrange driver is smaller than any that Kef ever used  https://www.diyaudio.com/community/threads/kef-concerto-improved-dn12-crossover-with-full-ab-circuit.370666/

 

The Gale schematic below,  too is useful to see how a three way crossover works

 

 

 

No-one to help, its just little old me, my daughter and wife, we have lived interstate from family for 20 years.

You say my drivers are 3 way, but was it originally 4 way until I chopped out the rear facing driver? 

[stereo coffee]

24 minutes ago, The Jam said:

 

No-one to help, its just little old me, my daughter and wife, we have lived interstate from family for 20 years.

You say my drivers are 3 way, but was it originally 4 way until I chopped out the rear facing driver? 

No still 3 way as each driver front and rear is a B200 , but in there, a clue. By tidying up the wiring - taking lots of images firstly I can help draw you a schematic of what is presently there.    If the drivers are in parallel then the impedance halves with respect to bass, @Cloth Ears is quite correct taking that driver out has upset the whole crossover - which i don't think was right in the first place..

 

If you can take some close ups on different angles, i will have a go at drawing the schematic as it is presently there,   for you. We can then see and compare to the Kef schematic , and after that see how we insert the midrange driver 

[Cloth Ears]

23 minutes ago, The Jam said:

 

No-one to help, its just little old me, my daughter and wife, we have lived interstate from family for 20 years.

You say my drivers are 3 way, but was it originally 4 way until I chopped out the rear facing driver? 

No, still a three way, but you did two things - cut the midbass/bass driver in half (by cone area) - changed the impedance that the amplifer sees for the midbass/bass driver (which probably changes the way the crossover works).

The second opinion is probably a bit simplified, as I'm not sure what you did with the 'cut wire' when you removed the second driver. If you just sticky-taped them up, then possibly it was a "3.5-way", where the second driver only worked below a certain frequency (generally decided by the width of the cabinet). In which case, you would be missing a bunch of bass+mid-bass from maybe 300Hz down...

[The Hurting]

 

6 hours ago, stereo coffee said:

No still 3 way as each driver front and rear is a B200 , but in there, a clue. By tidying up the wiring - taking lots of images firstly I can help draw you a schematic of what is presently there.    If the drivers are in parallel then the impedance halves with respect to bass, @Cloth Ears is quite correct taking that driver out has upset the whole crossover - which i don't think was right in the first place..

 

If you can take some close ups on different angles, i will have a go at drawing the schematic as it is presently there,   for you. We can then see and compare to the Kef schematic , and after that see how we insert the midrange driver 

 

I did a kindergarten picture.

Edited May 11, 2023 by The Hurting

[stereo coffee]

20 hours ago, The Jam said:

 

No-one to help, its just little old me, my daughter and wife, we have lived interstate from family for 20 years.

You say my drivers are 3 way, but was it originally 4 way until I chopped out the rear facing driver? 

Thanks for that diagram, it shows the B 200 is being preceded  by a inductor to ground, which is very close electrically to a short. Where inductors can go across each polarity is where they do so in crossovers where a capacitor breaks the DC path which occurs for midrange and higher frequencies . The attached shows what is occurring.  i will post up recommendations. It is unknown from your diagram where the + and - leads are going , but I am assuming is as you have drawn it  indicating polarity wiring from the binding posts, by using the + and - symbol. 

Edited May 12, 2023 by stereo coffee

[The Hurting]

On 11/05/2023 at 8:37 AM, stereo coffee said:

It would appear there is no following of a crossover schematic , rather a layout that is " let's see what happens" . This might give you some ideas

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

You are correct, I am meaning to suggest those wires lead to the binding posts. Ta.

[The Hurting]

Im wondering what the rear facing speaker is all about? Should I bother to reinstall it or leave it out? the speakers can only be about 30cm from the wall in my current house. Producers, mixers and engineers never made recordings with strange configurations in mind.  Or does it add to the soundstage and I'd be silly to remove it?

[andyr]

18 minutes ago, The Hurting said:

Im wondering what the rear facing speaker is all about? Should I bother to reinstall it or leave it out? 

 

Removing it will change the impedance of the driver seen by one of the XO sections.  Hence the roll-off point of that filter will change.

 

[muon*]

Yes put them back in.

[Cloth Ears]

14 minutes ago, andyr said:

 

Removing it will change the impedance of the driver seen by one of the XO sections.  Hence the roll-off point of that filter will change.

 

I ran it through my simulator and it looks like removing the driver would probably give a peak (at least 3dB) just below the crossover point, but might not change it enough to damage any of the drivers. Mind you, removing half your cone are will affect output and also how the passive radiator is loaded.

And as the crossover is fairly opaque, it might be that the second driver was the .5 of a 3.5-way, which means that there will be quite a drop in output from 250-300Hz (due to the missing driver).

34 minutes ago, The Hurting said:

Im wondering what the rear facing speaker is all about? Should I bother to reinstall it or leave it out? the speakers can only be about 30cm from the wall in my current house. Producers, mixers and engineers never made recordings with strange configurations in mind.  Or does it add to the soundstage and I'd be silly to remove it?

I'd say it was put there as the original designer was able to have his speakers a few metres into the room. But there should be no major reason why you couldn't have both drivers on the same front panel. You'd have to make them yourself, but you have the original ones to use as a template for the holes for the drivers and build one yourself. This would also avoid the issues you might have when the drivers are aligned down the centre of the box. And as the ones you have are screwed onto the cabinet, replacement might be quite easy...

[The Jam]

As much as I messed up the x-over removing the rear facing speackers, in my space, just 30cm from the wall, the bass seems more controlled and the high less shrill without them. But I'm without music at all for now, I'm too scared to use them in case I ruin my amp or the speakers.

[The Jam]

9 hours ago, Cloth Ears said:

I ran it through my simulator and it looks like removing the driver would probably give a peak (at least 3dB) just below the crossover point, but might not change it enough to damage any of the drivers. Mind you, removing half your cone are will affect output and also how the passive radiator is loaded.

And as the crossover is fairly opaque, it might be that the second driver was the .5 of a 3.5-way, which means that there will be quite a drop in output from 250-300Hz (due to the missing driver).

I'd say it was put there as the original designer was able to have his speakers a few metres into the room. But there should be no major reason why you couldn't have both drivers on the same front panel. You'd have to make them yourself, but you have the original ones to use as a template for the holes for the drivers and build one yourself. This would also avoid the issues you might have when the drivers are aligned down the centre of the box. And as the ones you have are screwed onto the cabinet, replacement might be quite easy...

 

Dang, Great idea, but I just measured it up, and the b200 and the mid wont fit side by side (well they, will but there is about 5mm between them and even if it squeezes in, would look but ugly.)

[sir sanders zingmore]

5 hours ago, The Jam said:

As much as I messed up the x-over removing the rear facing speackers, in my space, just 30cm from the wall, the bass seems more controlled and the high less shrill without them. But I'm without music at all for now, I'm too scared to use them in case I ruin my amp or the speakers.

This is confusing, do you have the same issue as @The Hurting?

[The Jam]

9 minutes ago, sir sanders zingmore said:

This is confusing, do you have the same issue as @The Hurting?

No sorry, seems I joined in march 2022 then moved house, lost the plot couldn't remember log in details etc, so rejoined in Sept on my phone when in hospital. Then recently unpacked desktop computer computer, seems my desktop computer remembers my original account automatically, sorry hadn't noticed, If I post on my phone its the account I started anew from my phone, on my desktop its the account I couldn't get into. (I wont talk about my head injury, just say, sorry for the confusion, I hadn't noticed).

[Fenda]

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