A tweeter section sees about 10W maximum, usually less. So the 4.7R should be a 10W. The shunt 22R and 1.3R below sees less current, so a 3-7W will do.
Any polypropylene capacitor will do. 250V types are smaller, so useful here.
Attachments
Hi All/Steve,
I do hope you are all keeping well and safe under these troubled times
Sorry its taken over 4 years to get back on here but I've had the most amazing 4 years establishing my own consultancy business and working on some amazing construction projects.
I packed these speakers away in my garden workshop (heated and dehumidified)and have now established a hifi system in my small office.
Steve - with regards to the schematic are you indicating that I need to add a 22R shunt resistor, a 4.7R and a 4.7uF cap too. I can replace the 2.30mH coil - what would you recommend?
Again, apologies for taking so long to get back to you all.
Kindest Regards
Rob
I do hope you are all keeping well and safe under these troubled times
Sorry its taken over 4 years to get back on here but I've had the most amazing 4 years establishing my own consultancy business and working on some amazing construction projects.
I packed these speakers away in my garden workshop (heated and dehumidified)and have now established a hifi system in my small office.
Steve - with regards to the schematic are you indicating that I need to add a 22R shunt resistor, a 4.7R and a 4.7uF cap too. I can replace the 2.30mH coil - what would you recommend?
Again, apologies for taking so long to get back to you all.
Kindest Regards
Rob
Hi Rob. A good speaker takes years to perfect, IMO. It's the hobby!
Did Dissi get it about right? Can't quite remember. 😕
The M21 isn't wildly different from the P21 anyway. I did find a design not a million miles away from yours:
P21WO20+ R2604-8330 2way Passive Crossover Design - Madisound Speaker PDF Library
10uF/0.3mH and 3.3R and 47R attenuator on the 2kHz R2604 crossover.
Bass is a bit different, using impedance correction. 0.8mH series, 12uF and 3.3R shunt, 5.6R and 40uF (39uF surely...) impedance correction.
Seems a bit low crossover to me, but who knows?
My old 8" speakers were very simple:
Restoring Monitor Audio R300 bookshelf speakers.
You can draw up a tidy schematic in Boxsim: Software | Visaton
I think we need a good schematic with values. The rest should be straightforward.
Did Dissi get it about right? Can't quite remember. 😕
The M21 isn't wildly different from the P21 anyway. I did find a design not a million miles away from yours:
P21WO20+ R2604-8330 2way Passive Crossover Design - Madisound Speaker PDF Library
10uF/0.3mH and 3.3R and 47R attenuator on the 2kHz R2604 crossover.
Bass is a bit different, using impedance correction. 0.8mH series, 12uF and 3.3R shunt, 5.6R and 40uF (39uF surely...) impedance correction.
Seems a bit low crossover to me, but who knows?
My old 8" speakers were very simple:
Restoring Monitor Audio R300 bookshelf speakers.
You can draw up a tidy schematic in Boxsim: Software | Visaton
I think we need a good schematic with values. The rest should be straightforward.
This is nice too, and simpler:
P21WO20+ D2606-9220 2way Passive Crossover Design - Madisound Speaker PDF Library
1mH and shunt 8.2R plus 22uF on bass. 6uF and 0.6mH on the tweeter, 2.2R plus 15R attenuator.
The Scan D2606-9220 is an old vifa or peerless design, IIRC. 91dB tweeter much like your SEAS. Can't remember how different the P21 is from the M21, But the filter might work very well. Sort of thing I like doing. Sounds OK.
Or we just tweak your Mission filter.
P21WO20+ D2606-9220 2way Passive Crossover Design - Madisound Speaker PDF Library
1mH and shunt 8.2R plus 22uF on bass. 6uF and 0.6mH on the tweeter, 2.2R plus 15R attenuator.
The Scan D2606-9220 is an old vifa or peerless design, IIRC. 91dB tweeter much like your SEAS. Can't remember how different the P21 is from the M21, But the filter might work very well. Sort of thing I like doing. Sounds OK.
Or we just tweak your Mission filter.
Thanks Steve and very good to hear from you.
Let me 'try' to draw up the schematic of the current system and then we will work from there.
Since we were last in contact, I've added a Arcam Alpha 5 Plus CD player (purchased as fully recapped, upgraded clock and new op amps - sounds terrific) and Dali Zensor 1's. The speakers are ok but are a wee bit bright and not as dynamic for my liking. I have a feeling that these 770s may be too big for my office but will give it a try.
Best Regards
Rob
Let me 'try' to draw up the schematic of the current system and then we will work from there.
Since we were last in contact, I've added a Arcam Alpha 5 Plus CD player (purchased as fully recapped, upgraded clock and new op amps - sounds terrific) and Dali Zensor 1's. The speakers are ok but are a wee bit bright and not as dynamic for my liking. I have a feeling that these 770s may be too big for my office but will give it a try.
Best Regards
Rob
Big speakers in small rooms. Always boomy! 😀
Tone controls?
Did we decide it's a 2.3mH bass coil in Dissi's guess?
Does look bright at the top if I haven't lost my touch. But you can tone down bass with a smaller bass coil.
Tone controls?
Did we decide it's a 2.3mH bass coil in Dissi's guess?
Does look bright at the top if I haven't lost my touch. But you can tone down bass with a smaller bass coil.
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Hi Steve
The problem was originally that these were too bright and aggressive with not much bass.
Let me try to draw out the existing schematic as a start - I will try to do this today.
I have a greater concern that they will be too big to fit in the office as its only 2.5 x 2.5m square (its a dormer in the roof).
Best Regards
Rob
The problem was originally that these were too bright and aggressive with not much bass.
Let me try to draw out the existing schematic as a start - I will try to do this today.
I have a greater concern that they will be too big to fit in the office as its only 2.5 x 2.5m square (its a dormer in the roof).
Best Regards
Rob
If it's 2.3mH and 0.36mH, we have enought to go on.
Tweeter definitely too loud. Crossing way to low too, IMO. Would have to look at the spec sheet for the woofer to know if it will work in reflex. This is not difficult. Might spend £20 on components.
Hi Steve
I will double check but the first coil readings were 0.36mH for the tweeter and 2.3mH for the bass. I have no issues in spending a bit of money to get these up and running.
the stands that I'm using are 1.5m to sit above my desk at the back of the room so I hope that these wont be too high up?
Best Regards
Rob
I will double check but the first coil readings were 0.36mH for the tweeter and 2.3mH for the bass. I have no issues in spending a bit of money to get these up and running.
the stands that I'm using are 1.5m to sit above my desk at the back of the room so I hope that these wont be too high up?
Best Regards
Rob
I have the PDFs for the P21W0-20-08 and the M21WJ-09-08 and they are almost identical. 🙂
So this is good, IMO. In fact may build it myself, since I have the parts.
P21WO20+ D2606-9220 2way Passive Crossover Design - Madisound Speaker PDF Library
But I think we can do something with your existing bits. Just need to lower the crossover and attenuate a bit more. I think a 4.7uF or even a 3.3uF capacitor would work better than the 10uF. And add about 3.3R 3W or 7W wirewound aka ceramic in front for about 3dB attenuation.
But I really ought to get going now. Will look in soon.
So this is good, IMO. In fact may build it myself, since I have the parts.
P21WO20+ D2606-9220 2way Passive Crossover Design - Madisound Speaker PDF Library
But I think we can do something with your existing bits. Just need to lower the crossover and attenuate a bit more. I think a 4.7uF or even a 3.3uF capacitor would work better than the 10uF. And add about 3.3R 3W or 7W wirewound aka ceramic in front for about 3dB attenuation.
But I really ought to get going now. Will look in soon.
Me and (broken) Windows 7 have fallen out of love recently, so simming is problematic. 😱
Here's the plan. We replace 10uF with 3.3R (3W) in series with 3.9uF.
PM me your address, And I have already wrapped up the components along with a bit of 15A fusewire and some unleaded solder. You just need a modern 40W soldering iron, available from screwfix or such for about £15.
Let's get on with this. 😎
Here's the plan. We replace 10uF with 3.3R (3W) in series with 3.9uF.
PM me your address, And I have already wrapped up the components along with a bit of 15A fusewire and some unleaded solder. You just need a modern 40W soldering iron, available from screwfix or such for about £15.
Let's get on with this. 😎
Yup, that's what I was thinking. Just lash it up.If it goes open circuit, it'll do no harm.
Ages since I have done this, but I suspect the tweeter goes negative polarity in this one.
I must have known what I was doing here:
Ages since I have done this, but I suspect the tweeter goes negative polarity in this one.
I must have known what I was doing here:
Hi,
I do apologise that its taken this long to reply on this forum but now being at the point of earlyish retirement (I'm 62 now) I have a chance to get back to work on my hifi system. I am pleased to say that I've modified the crossovers and that the speakers are working extremely well; very well balanced and neutral with the A&R A60 (no treble or bass alterations amp wise). The only issue now is the size of them - they are in our new house extension which is about 3m x 3m so they look huge! I will stick with them but I would like to seek something a little smaller over time that can deliver the same overall sound if this is at all possible?
Best Regards
Rob
I do apologise that its taken this long to reply on this forum but now being at the point of earlyish retirement (I'm 62 now) I have a chance to get back to work on my hifi system. I am pleased to say that I've modified the crossovers and that the speakers are working extremely well; very well balanced and neutral with the A&R A60 (no treble or bass alterations amp wise). The only issue now is the size of them - they are in our new house extension which is about 3m x 3m so they look huge! I will stick with them but I would like to seek something a little smaller over time that can deliver the same overall sound if this is at all possible?
Best Regards
Rob
I have done an active crossover for these. See https://brianpowellaudio.co.uk/brian-powell-audio-electronics-data/bpa-active-crossover