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Hello!
 

I have been looking for a pair of speakers to try my hand at some diy work on speakers and picked these up off GT the other day. 
 

Appropriately badged, I thought the drivers maybe some good… and then it dawned on me I did not recall Blaupunkt ever being known for their home speakers.

 

Initially I thought I would just paint the rears, maybe redo the grill cloths and then try my hand at some vinyl wrap on them. 
 

Opened them up and this is what I found.

 

Now, it seems like there is a lot more work to be done and potentially the only thing that  makes it a worthwhile  project are the cabinets as they actually seem alright to me.

 

Which leads me to ask the below in no particular order. 
 

- Does that bottom  driver look right?!?!  Does it not need a magnet attached to the back of it? Not sure why it was kept there as it wasn’t even connected. 

- In the way of crossovers, any recommendations for someone with no soldering skills.  Will be happy to learn and give it a go as well with this project. I looked at some cheap ones on eBay and would also be happy to pick up some off anyone here on the forum if they were looking at getting rid of them. 
- Is this actually worthwhile, other than learning to do it?

- With the capacitor between the tweeter and woofer, will I need to remove it as well in order to install the crossover.

- I will look at replacing the speaker wire and introducing some speaker terminals as well for a neater finish to them.

- Any recommendations and thoughts on this would be more than welcome. 

 

Ideally I want to leant some of these skills and in the event the speakers look good and sound alright will be bonus!
 

 

Thanks in advance

 

 


 

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Bottom is a passive radiator. meant to be like that. indicates reasonably sophisticated design

 

 

compared to a typical cheap speaker that is. 

 

Dont underestimate the quality of these and definitely listen to them before butchering. Crossover design is not trivial and not something you can easily "wing". Understand you want to have a go and that is admirable.  Keep the old bits and take a photo of the configuration so you can replace and compare after your tweaks.

Edited by frednork
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I began in a similar way...  by modifying a Sony surround system.  It depends on what you are aiming for, but the skills required to achieve great sounding speakers include woodwork, painting / finishing, soldering...  but, also the technical side of driver specs, and crossovers.

 

As you have cabinets and drivers, the crossovers will be your biggest challenge.  However, as mentioned, it depends on what your aiming for.

 

The crossover filters the signal, sending the preferred frequencies to each driver.  The single capacitor between the woofer and tweeter is filtering out the lower frequencies, so the tweeter only gets the higher ones.  As the input speaker wire connects straight to the woofer, it has no filter, and is receiving the full range of frequencies.  My first step would be to add an inductor to the woofer, filtering out the higher frequencies.

 

As you learn, you will find that a well designed crossover does so much more than filtering, and is not easy without software and measurement.  Buying a ready made crossover would rely on sheer luck as they are not driver and cabinet specific.  I suggest buying a few capacitors, inductors and resistors, do some reading and experiment.

 

BE WARNED...  I HAVE BLOWN TWO AMPS BY NOT MEASURING IMPEDANCE PRIOR TO TESTING.

 

If you wish to learn these skills as I am doing, then I say go for it and play around.  Starting off with something cheap is a good idea, but it's an addictive venture and could become expensive as you require / aquire tools and equipment.

 

Many DIYers begin with kit speakers to learn the basics.  My plan is to learn the skills by modifying and restoring older speakers.  If you begin with your Blaupunkt cabinets, the next step could be restoring a nice pair of vintage speakers, also as I am doing.

 

Regards.

Ant.

Edited by BuzzzFuzzz
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53 minutes ago, frednork said:

Bottom is a passive radiator. meant to be like that. indicates reasonably sophisticated design

 

 

compared to a typical cheap speaker that is. 

 

Dont underestimate the quality of these and definitely listen to them before butchering. Crossover design is not trivial and not something you can easily "wing". Understand you want to have a go and that is admirable.  Keep the old bits and take a photo of the configuration so you can replace and compare after your tweaks.

Thank you! Just learnt something new!

 

I was definitely not going to try my hand at designing a crossover. However considered putting a ready made one in. Clearly just for the two drivers then. 

 

Would this be something to consider or best leaving the wiring the way it is?

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2 minutes ago, Special K said:

Thank you! Just learnt something new!

 

I was definitely not going to try my hand at designing a crossover. However considered putting a ready made one in. Clearly just for the two drivers then. 

 

Would this be something to consider or best leaving the wiring the way it is?

As @BuzzzFuzzz said chucking any old off the shelf crossover in is unlikely to improve on the original because they probably knew what they were doing.  As far as changing it goes, if you want to have a play then sure but sounds like you may need to get some basic knowledge to prevent damaging something. 

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On 15/06/2021 at 11:18 PM, frednork said:

As @BuzzzFuzzz said chucking any old off the shelf crossover in is unlikely to improve on the original because they probably knew what they were doing.  As far as changing it goes, if you want to have a play then sure but sounds like you may need to get some basic knowledge to prevent damaging something. 

 

Totally agree that I do need some basic knowledge and there was no

initial intent to go that extent when these were picked up. 

On 15/06/2021 at 11:20 PM, BuzzzFuzzz said:

Here's a link I found useful...

 

https://www.diyaudio.com/forums/multi-way/189847-introduction-designing-crossovers-measurement.html

 

As @frednork emphasizes, reading up is a must...  as is a multimeter.

Thank you for the link!  Definitely some reading to do and potentially some ods and ends to pick up along the way. 

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On 15/06/2021 at 11:06 PM, BuzzzFuzzz said:

I began in a similar way...  by modifying a Sony surround system.  It depends on what you are aiming for, but the skills required to achieve great sounding speakers include woodwork, painting / finishing, soldering...  but, also the technical side of driver specs, and crossovers.

 

As you have cabinets and drivers, the crossovers will be your biggest challenge.  However, as mentioned, it depends on what your aiming for.

 

The crossover filters the signal, sending the preferred frequencies to each driver.  The single capacitor between the woofer and tweeter is filtering out the lower frequencies, so the tweeter only gets the higher ones.  As the input speaker wire connects straight to the woofer, it has no filter, and is receiving the full range of frequencies.  My first step would be to add an inductor to the woofer, filtering out the higher frequencies.

 

As you learn, you will find that a well designed crossover does so much more than filtering, and is not easy without software and measurement.  Buying a ready made crossover would rely on sheer luck as they are not driver and cabinet specific.  I suggest buying a few capacitors, inductors and resistors, do some reading and experiment.

 

BE WARNED...  I HAVE BLOWN TWO AMPS BY NOT MEASURING IMPEDANCE PRIOR TO TESTING.

 

If you wish to learn these skills as I am doing, then I say go for it and play around.  Starting off with something cheap is a good idea, but it's an addictive venture and could become expensive as you require / aquire tools and equipment.

 

Many DIYers begin with kit speakers to learn the basics.  My plan is to learn the skills by modifying and restoring older speakers.  If you begin with your Blaupunkt cabinets, the next step could be restoring a nice pair of vintage speakers, also as I am doing.

 

Regards.

Ant.

Thanks @BuzzzFuzzz for your response and time spent. 

 

The aim is to pick up some skills and be able to potentially give some speakers an extended life as and when needed.  

 

I do enjoy looking after equipment like most people here. 

 

I can see how this can be addictive and not cheap... I already started off on vinyl and that is bad enough. 

 

I did consider a kit speaker however did not want to commit as yet and this would be the test (for myself) to find out how much I enjoy it. 

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Ok. So far I have put it back together to give it a decent listen and it sounds ok.  No rattle, fairly clean mids and ok highs.  Just no bottom end to be heard. 

 

At this stage this is what I have in mind for the project. 

 

- Replace internal cables. 

- Paint/Vinyl Wrap the boxes (this will include patching up some damage to them)

- Replace cloth grills

- Add speaker terminals

 

If I feel like they are worthwhile playing with further I will look at crossovers, just not sold on the drivers as yet as they do seem to be cheap ones.

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22 minutes ago, Special K said:

Ok. So far I have put it back together to give it a decent listen and it sounds ok.  No rattle, fairly clean mids and ok highs.  Just no bottom end to be heard. 

Just check you havent reversed polarity on the woofer. If there is no / low bass when both are playing see if it changes when you they face each other as opposed to being at 90 degrees. other way to check is to connect a battery to the terminals . + to +  and - to - should make the woofer move outward. If its opposite it will move in . if it doesnt move it may be cactus.

Edited by frednork
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22 minutes ago, frednork said:

Just check you havent reversed polarity on the woofer. If there is no / low bass when both are playing see if it changes when you they face each other as opposed to being at 90 degrees. other way to check is to connect a battery to the terminals . + to +  and - to - should make the woofer move outward.

Just checked it with a battery and both woofers moved forward. Which seems to indicate the polarity is right. 
 

I feel my comparison for these speakers is not fair though as my other speakers are bit better than these. 

0085B709-56E9-42DF-AEAE-DC4ED12E5910.jpeg

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Started taking them apart a few days ago.  Took the 600 staples around the baffles to neaten it up a bit more and will start painting them shortly. 

 

Just not sure if these staples underneath should remain or not as I can’t seem to see any other purpose other than maybe someone tried holding the vinyl wrap down and or attempted to attach something to the bottom of it. 

 

Vinyl wrap arrived yesterday however I am going to ask a friend of mine to help strengthen the boxes up before I go any further with them.  

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  • 3 weeks later...

Finally got to getting the first undercoat on today and will try and get a second on on today as Melbourne has some sunshine!

 

Trying to work out how I connect the cables on the inside and also be able to remove the rears as well in the future if I decide to change the drivers.

 

I picked up these terminals and cut the new holes in for them. I may keep the internal wiring for now however. 
 

Any recommendations on how to get this wired up and be able remove the rear completely off if needed?

 

 

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  • 2 weeks later...

Slow process, however progress is progress nevertheless. 
 

Painted the front and rear of the cabinets and did the cloths on the front. 
 

I used staples in the end. Lesson learnt with the finish, use a sharper pair of scissors to cut the cloth. 
 

The new speaker terminals were also added and fit nice and snug. 
 

Happy with the outcomes so far, for someone that has never used a jigsaw or staple gun prior. 

Next is to consider redoing the internal wiring on them. 
 

I picked up a pair of used Logitech woofers and will trial them out during that process. 

 

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On 7/10/2021 at 1:57 PM, Special K said:

Trying to work out how I connect the cables on the inside and also be able to remove the rears as well in the future if I decide to change the drivers.

Hey mate.

 

Great work.

I use bare wire connections, no solder, to connect my drivers for easy swapping in and out.  I insulate all bare wire with insulation tape.  Sometimes I do use crimp lugs with spade terminals, as seen in many speakers...  but I would suggest using quality lugs, instead of the cheapies found in auto shops.

 

The only way to be able to remove the rear, is to screw it on.  When you're satisfied with the set up, glue and screw.

 

I see the drivers are mounted from the inside, so once you've glued the back on, you won't be able to get back inside.  I would simply screw the back on...  Or you could try mounting the drivers from the outside, if they fit, allowing you to get inside by removing the drivers.  This way, you can glue and screw the back on, and be satisfied there will be no vibration.  It's a bit time consuming, as you may need a couple of applications for such big cracks...  and a smooth finish.

 

I should have chimed in earlier, before you applied the first coat of paint.  Looking at the pics, I see the edges of the chip board have some pretty big cracks.  I usually fill those with wood filler, to seal the ends, and give them a longer life, as they will continue to break up over time.

 

1 hour ago, Special K said:

Slow process, however progress is progress nevertheless. 

My Technics cabinets rebuilds have been going for over 12 months, although, I have many other projects going at the same time.  If I have learnt anything in my time here, it's patience.  Slow and steady wins the race.

 

I'm curious if you have a link for your grille cloth, as I like the colour, and have a few grilles to re-cover.

 

Cheers Man.

Keep it up.

Ant.

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3 hours ago, BuzzzFuzzz said:

Hey mate.

 

Great work.

I use bare wire connections, no solder, to connect my drivers for easy swapping in and out.  I insulate all bare wire with insulation tape.  Sometimes I do use crimp lugs with spade terminals, as seen in many speakers...  but I would suggest using quality lugs, instead of the cheapies found in auto shops.

 

The only way to be able to remove the rear, is to screw it on.  When you're satisfied with the set up, glue and screw.

 

I see the drivers are mounted from the inside, so once you've glued the back on, you won't be able to get back inside.  I would simply screw the back on...  Or you could try mounting the drivers from the outside, if they fit, allowing you to get inside by removing the drivers.  This way, you can glue and screw the back on, and be satisfied there will be no vibration.  It's a bit time consuming, as you may need a couple of applications for such big cracks...  and a smooth finish.

 

I should have chimed in earlier, before you applied the first coat of paint.  Looking at the pics, I see the edges of the chip board have some pretty big cracks.  I usually fill those with wood filler, to seal the ends, and give them a longer life, as they will continue to break up over time.

 

My Technics cabinets rebuilds have been going for over 12 months, although, I have many other projects going at the same time.  If I have learnt anything in my time here, it's patience.  Slow and steady wins the race.

 

I'm curious if you have a link for your grille cloth, as I like the colour, and have a few grilles to re-cover.

 

Cheers Man.

Keep it up.

Ant.


Hey Ant,

 

Thanks for the feedback, I think it looks pretty good, but I am biased…

 

I went and ordered these and waiting for this to come in, ideally to help me with the swapping in and out if needed. 
 

https://www.ebay.com.au/itm/270pc-Electrical-Wire-Connector-Assorted-Insulated-Terminal-Spade-Crimp-AU-L0A4-/265098321063?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=705-154756-20017-0

 

They seem pretty straight forward and would possibly give a half decent connection at the same time. I will leave some extra length on the inside to be able to remove the rear, place it aside and then unhook the cables.  That is the thought process so far.  
 

Ha,  yeah I did use some filler and some of them I was ok with keeping in there. It helps with my ocd. 😬

 

I did do some work on the cabinets as the corners were pretty rough and I didn’t want the vinyl to be all uneven when that comes on. 
 

Yeah, I can see that. It does take some time to get it done, hence I may take on another while this is midstream. 
 

The link for the grill cloths are below.

 

https://www.ebay.com.au/itm/1m-1-5m-Grill-Mesh-Fabric-Speaker-Radio-Net-Sport-Cloth-DIY-Craft-Free-Shipping-/283889144052?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=705-154756-20017-0

 

When it first got here, we were a bit worried with the choice, however once it went on with the black background it gave us the desired end result. 
 

My partner is Dutch and hence the choice in colour, which she picked. 

 

Cheers

 

Keith

 

 

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