Just assembled my first 'hifi' rig on the weekend.
(furniture solution pending)
Full disclosure - I'm not a hifi person, I don't know anything.
All I do know is about guitar amplifiers, speakers, pedals, FX, etc.
The reason I'm here is because I finally got around to procuring some hifi speakers to test/accompany this stereo tube amp I built last year.
here's one of the speakers
found on gumtree for (what i consider to be) a good deal.
i am told (& as per listing) they were built in the 1970s (by the seller’s DIY/enthusiast brother)
- cabinet dimensions:
75cm / 29.5” tall
48cm / 18.9” wide
30cm / 11.8” deep
constructed with 3/4” particle board.
- 12” drivers are Philips AD12100/W8
(yet to actually confirm, but it looks like they might be?)
the dust caps have ‘perished’ 😟
- apparently the other drivers are also philips/netherlands origin.
(looks like midrange drivers might be AD0210/AD0211, tweeters could be AD0160?)
Maybe my ears just aren’t golden enough, but to me this setup sounds shockingly good - especially considering the bandwidth-limiting guitar OTs etc.
also,
so how much does it matter about the missing dust caps on the 12” drivers?
- is it worth attempting to repair/replace them myself? (implied dustcap footprint diameter appears to be 70-72mm)
also one of the midrange drivers is a little bit squished/dented
- should i just leave it? or can this be remedied?
[I acknowledge there's queries in here that may be better posted in a specific thread/sub-forum, but I can't do that right now]
(furniture solution pending)
Full disclosure - I'm not a hifi person, I don't know anything.
All I do know is about guitar amplifiers, speakers, pedals, FX, etc.
The reason I'm here is because I finally got around to procuring some hifi speakers to test/accompany this stereo tube amp I built last year.
here's one of the speakers
found on gumtree for (what i consider to be) a good deal.
i am told (& as per listing) they were built in the 1970s (by the seller’s DIY/enthusiast brother)
- cabinet dimensions:
75cm / 29.5” tall
48cm / 18.9” wide
30cm / 11.8” deep
constructed with 3/4” particle board.
- 12” drivers are Philips AD12100/W8
(yet to actually confirm, but it looks like they might be?)
the dust caps have ‘perished’ 😟
- apparently the other drivers are also philips/netherlands origin.
(looks like midrange drivers might be AD0210/AD0211, tweeters could be AD0160?)
- vinyl player is a cheap entry level (AUD$90 in 2012 i think)
- ultra budget phono preamp ($20?) - runs on 12V DC supply (opened it up the other day, it’s thru-hole, looks like it might be running either NE5532 or TL072, cant really see, there’s a steel shield heavily soldered over the top of part of the PCB)
Maybe my ears just aren’t golden enough, but to me this setup sounds shockingly good - especially considering the bandwidth-limiting guitar OTs etc.
also,
- supposedly the crossovers have never been recapped (wish me luck with opening the back panels)
- i’m an idiot and tested them with totally mismatched 12AX7s so the 2 channels had slightly different tone and gain (making it more difficult to level match) but it didn’t matter, still sounded great.
so how much does it matter about the missing dust caps on the 12” drivers?
- is it worth attempting to repair/replace them myself? (implied dustcap footprint diameter appears to be 70-72mm)
also one of the midrange drivers is a little bit squished/dented
- should i just leave it? or can this be remedied?
[I acknowledge there's queries in here that may be better posted in a specific thread/sub-forum, but I can't do that right now]
Welcome to diyAudio :^)
Looks like an old Philips kit. The XO provided sucks.
Nice equipment stands, you need some short ones for the speakers.
dave
Looks like an old Philips kit. The XO provided sucks.
Nice equipment stands, you need some short ones for the speakers.
dave
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@planet10 appreciate the reply.
could you please elaborate on how/why this crossover sucks? not trying to be smartass, just trying to understand/learn 🙂
(I did try to search for an answer to this but getting vague info)
So instead of recapping the existing crossovers, I should replace them with a better/revised XO circuit?
I guess I could start asking for XO suggestions once I can get inside and confirm the ID of the drivers.
@Harry72
could you please elaborate on how/why this crossover sucks? not trying to be smartass, just trying to understand/learn 🙂
(I did try to search for an answer to this but getting vague info)
So instead of recapping the existing crossovers, I should replace them with a better/revised XO circuit?
I guess I could start asking for XO suggestions once I can get inside and confirm the ID of the drivers.
@Harry72
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Recapping isn’t meant to make an improvement, just to extend the life of the crossover with respect to a certain type of capacitor.
@AllenB understood, and agreed.
however, if these crossovers are 50 years old, one would assume that any electrolytic caps present would be well past their service life? that's my only real concern.
regardless, it appears @planet10 is suggesting these crossovers aren't worth the attention.
Once I get a chance to actually open the cabinets and properly identify the drivers, I guess I can start asking for crossover schematics.
however, if these crossovers are 50 years old, one would assume that any electrolytic caps present would be well past their service life? that's my only real concern.
regardless, it appears @planet10 is suggesting these crossovers aren't worth the attention.
Once I get a chance to actually open the cabinets and properly identify the drivers, I guess I can start asking for crossover schematics.
I used more tha a few. It was a “universal” XO with textbook values. And not great parts.Now tag gthey are some 50 years old, the caps are likely not even close to the spec. The XO is nominally 500/4500 Hz, likely too low for the dome midrange (i nhave only come across dead ones)
The circuit board is poor as well.
You might want to swap tweeters whike you are at it, the AD-0160 is not great.
No dust cap on the woofer a good thing, you shoud build up a felt "phase plug” to kill the cavity/beer can resonance in the hole inside the voice coil. A wooden oplug would be prettier.
dave
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Welcome to my world! 🙂
Not one whit, i.e. ~34400/pi/7.2 = ~1520 Hz - up, so historically 'we' would be damping them with felt/whatever, so with them off, just need to follow Davep10's advice.
I pulled them out using a hand vacuum pump, but if you like how they sound as is when doing an A/B test, why bother?
Re caps; since you're using tubes there's a certain synergy using PIO caps, not to mention technically better if modern ones haven't improved much since this testing was done.
@planet10 ahh yep.
i would agree 50Hz doesn’t seem like an ideal crossover point.
for now i’d like to see what results can be achieved with crossovers, and perhaps i might upgrade the tweeters at a later stage.
regarding the AD0160, any thoughts on this statement (post#7) about crossing over at 3K?
https://www.diyaudio.com/community/threads/philips-ad-0160-tweeter-replacement.234605/post-3467510
@GM PIO is cool, i would probably just use film/foil/poly, maybe electrolytic, depending on how much i feel like sinking into it 😅
still gotta try and get the back panels off first…
i would agree 50Hz doesn’t seem like an ideal crossover point.
for now i’d like to see what results can be achieved with crossovers, and perhaps i might upgrade the tweeters at a later stage.
regarding the AD0160, any thoughts on this statement (post#7) about crossing over at 3K?
https://www.diyaudio.com/community/threads/philips-ad-0160-tweeter-replacement.234605/post-3467510
good point..
@GM PIO is cool, i would probably just use film/foil/poly, maybe electrolytic, depending on how much i feel like sinking into it 😅
still gotta try and get the back panels off first…
Check your hearing with headphones before spending money on the tweeters and upper band of crossover. Many men are deaf above ~7000 hz. Plus, guitar amp output transformers should cut off about the same frequency. I would use ST70 copies from triodeelectronics.com if they still sell them. Just checked, still listed.
Sorry typo — lower XO at 500 Hz. The dome should probably be crossed 800-1000Hz.
Given that the tweeter is not so great, if itwas my project i woud consider adding a midTweeter for the top. For good budget one ni’d suggest Markaudio CHP-50. Run a 4” plumbing pipe out the back. leave it open at the back and create an aperiodic midTL. Simplifies the XO.
dave
In their 1978 handbook, Philips promoted the following 3-way combination of drivers:
Woofer: AD 12200/W8
Squawker: AD 0211/Sq8
Tweeter: AD 01605/T8
To be used with crossover frequencies of 800 Hz and 5,000 Hz in a 100 litre sealed enclosure.
Re: Dust caps: Queensland Speaker Repairs sells suitable replacements, & the glue to stick them on. Their web site is a bit clunky though: https://qsr.net.au/
ahhhh, this is an interesting point.
perhaps the sub-optimal bandwidth limiting guitar OTs are helping out here with the harsh tweeters...
good point. had another look and yep - there's x6 screws and a few nails holding the baffle in.
perhaps this might come out easier than the back panel (appears to have hermetically sealed itself after 50 years of air/moisture)
noted - thanks. will keep this in mind.
@Galu - interesting. thanks for that info.
had another quick look and popped out the midrange/dome/squawkers last night and confirmed they are indeed AD0210/SQ8.
with all this focus on the undesirable tweeters, i'm honestly a lot more concerned about the condition of these paper domes (AD0210)
the other one is a bit worse.
repairable? was thinking disassemble, push out dents, reassemble? (is this feasible? or a disaster waiting to happen?)
not sure if using adhesives / tapes is gonna be a good idea on the delicate paper surfaces...
i suspect replacements are going to cost more than what i paid for these speakers altogether... might just take @GM 's advice and leave them as is.
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I'd be worried that things might go wrong during disassembly.
GM gives good advice, although I'm sure if left in place those dents would keep on nagging you!
GM gives good advice, although I'm sure if left in place those dents would keep on nagging you!
+1 It would me too, but by the same token, when it comes to cost I'm not one to 'fix what ain't broke', though I always put decorative, yet sturdy, grills over speakers to protect them from various two, four legged 'critters' and a few birds in my time also.