Hi..
My first post here.
SoI have zero experience in audio DIY or electronics as such and have been hoping along with the help if many people...
So at this point let me mention the gear in question.
I don't know what's relevant so I will try post as much detail as possible.
Pls ignore irrelevant detail.
I have bought a used very well designed( I believe) set of 300B push pull mono blocks , using some Hammond transformers and Sowther interstages as well as electro harmonics 300b tubes.
I have no detail around the amps impedance etc... But I know it was used to drive the QUAD ESL 57's and do very well.
So on the speaker side I built a pair of JE LABS OB to the spec and originally just used a single Phillips AD12100 M8 in each.
In shirt I love the way it plays especially with my vinyl Frontend ...
The only thing that made me look further was the fact that it can become a bit bright / screamy with some recordings on higher( think the whizzer does that) volume and then again looses LF on lower volume..
So , eventually I struck my luck with a goodmans axiom 201 and tried this in the baffle .. They are different , but overall very mellow and musical and I love them too... Maybe a bit not as detailed / bright / on top as the Philips.
So I thought of merging this two ....
Here is the challenge for me begins..
I tried various combination of this in a single channel test baffle( I.e parallel , series , using them in a vintage isophon crossover network , etc..)
Bear in mind the goodmans is 15 ohm and the Philips is 8 ohm.
All the above seems promising , but there is always something missing( like they are not in sync nicely or something I cannot put my finger on).
Then I read about Thorstens Magnificat , which joins an axiom 80 with the 201 and he writes positively about the match..
I understand the Philips is different from the axiom 80 , but I would like to try this sort of merging two fullrange drivers of this quality with differing impedance loads.
The reason why I am so set to try do this , is because after splitting the drivers from the test baffle again , needless to say , I miss immediately the low's and definition one seem to can get from 2 12 inch drivers of this nature.
The other aim would be to try not use any complexes crossover networks as far as possible.
So I am in sire straits here and it bothers me as I at least wang to give this a fair chance.
Some other drivers at my disposal is ...
A full set of vintage Isophon stereo melodie and it's crossover..
This seems to limit the sound a bit as I set it to 15 ohms and tried 15 connecting the goodmans in place of the woofer and the Philips in place of the midrange and vice versa...
I also have 4 philips Ad8080( seem to say 15 ohms).
I also have a set of infinity RS3a woofers , which seems not suitable on OB.
I think I can get my hands on a pair of Kelly Ribbon's ,,but..
I would like to stop buying more drivers now and not knowing what to do with them..
I am not really in a position to measure etc.. As I am still trying to learn that as well,, but I suppose the main drivers in question does have some info online or lot of people seem knowledgeable on their roll off and recommended x over points etc..
Anyway.. I suppose that is that then...
Any advise , ideas ?
I will really appreciate it a lot..
Thanks a mill in advance.
Kind regards.
Julian
My first post here.
SoI have zero experience in audio DIY or electronics as such and have been hoping along with the help if many people...
So at this point let me mention the gear in question.
I don't know what's relevant so I will try post as much detail as possible.
Pls ignore irrelevant detail.
I have bought a used very well designed( I believe) set of 300B push pull mono blocks , using some Hammond transformers and Sowther interstages as well as electro harmonics 300b tubes.
I have no detail around the amps impedance etc... But I know it was used to drive the QUAD ESL 57's and do very well.
So on the speaker side I built a pair of JE LABS OB to the spec and originally just used a single Phillips AD12100 M8 in each.
In shirt I love the way it plays especially with my vinyl Frontend ...
The only thing that made me look further was the fact that it can become a bit bright / screamy with some recordings on higher( think the whizzer does that) volume and then again looses LF on lower volume..
So , eventually I struck my luck with a goodmans axiom 201 and tried this in the baffle .. They are different , but overall very mellow and musical and I love them too... Maybe a bit not as detailed / bright / on top as the Philips.
So I thought of merging this two ....
Here is the challenge for me begins..
I tried various combination of this in a single channel test baffle( I.e parallel , series , using them in a vintage isophon crossover network , etc..)
Bear in mind the goodmans is 15 ohm and the Philips is 8 ohm.
All the above seems promising , but there is always something missing( like they are not in sync nicely or something I cannot put my finger on).
Then I read about Thorstens Magnificat , which joins an axiom 80 with the 201 and he writes positively about the match..
I understand the Philips is different from the axiom 80 , but I would like to try this sort of merging two fullrange drivers of this quality with differing impedance loads.
The reason why I am so set to try do this , is because after splitting the drivers from the test baffle again , needless to say , I miss immediately the low's and definition one seem to can get from 2 12 inch drivers of this nature.
The other aim would be to try not use any complexes crossover networks as far as possible.
So I am in sire straits here and it bothers me as I at least wang to give this a fair chance.
Some other drivers at my disposal is ...
A full set of vintage Isophon stereo melodie and it's crossover..
This seems to limit the sound a bit as I set it to 15 ohms and tried 15 connecting the goodmans in place of the woofer and the Philips in place of the midrange and vice versa...
I also have 4 philips Ad8080( seem to say 15 ohms).
I also have a set of infinity RS3a woofers , which seems not suitable on OB.
I think I can get my hands on a pair of Kelly Ribbon's ,,but..
I would like to stop buying more drivers now and not knowing what to do with them..
I am not really in a position to measure etc.. As I am still trying to learn that as well,, but I suppose the main drivers in question does have some info online or lot of people seem knowledgeable on their roll off and recommended x over points etc..
Anyway.. I suppose that is that then...
Any advise , ideas ?
I will really appreciate it a lot..
Thanks a mill in advance.
Kind regards.
Julian
Hi,
since you started with the description of the tube amplifier, it should
be noted that it has output transformers, each one having the 'tapping' for different output loads. Usually it's 4 and 8 Ω, the older ones may have windings for 16 Ω loads. So it would be better to bear in mind that the output wants to 'see' an 'easy' load with flattish impedance and not a random mix.
I have no experience with tube amps but it's commonly said that the lower damping factor goes well with OB as the added resistance that the transformer winding adds
implies changes to the electrical part of the speaker,i.e. the resonance peak isn't much controlled ( well, excursion has to be controlled by the motor ) and so the bass is in evidence.
since you started with the description of the tube amplifier, it should
be noted that it has output transformers, each one having the 'tapping' for different output loads. Usually it's 4 and 8 Ω, the older ones may have windings for 16 Ω loads. So it would be better to bear in mind that the output wants to 'see' an 'easy' load with flattish impedance and not a random mix.
I have no experience with tube amps but it's commonly said that the lower damping factor goes well with OB as the added resistance that the transformer winding adds
implies changes to the electrical part of the speaker,i.e. the resonance peak isn't much controlled ( well, excursion has to be controlled by the motor ) and so the bass is in evidence.Thank you Picowall.
I do have access to some very experienced Valve amp builders locally and will ask their opinion on the items you mention.
So , in a nutshell what I tried to do was (assuming the amp is ok at 8 ohm), wire the Phillips in parallel with an 8 ohm load ( just another driver ) to make it about 16 ohm and wired that in parallel to the goodmans (15 ohm) which gave me a total of about 7- 8 ohms.
The problem was that the Phillips still showed it's claws on the HF when volume is pumped up a bit...
I am thinking I might have to get the Phillips up only play in the mids and lower somehow as well as making it look like a 15 or so OHM load( but without having to use a 3rd driver or contaminating it's sound quality) ,,, which I can then connect in parallel to the goodmans .
The reason why I think this is because I love the Goodmans as full range and just want the Phillips to bring along it's magical mids and sound low ( but not the screaming highs)...
Hope that makes sense though .
Tx again ( will let you know when I can have someone measure these amps and tell me exactly what they are capable of)...
I do have access to some very experienced Valve amp builders locally and will ask their opinion on the items you mention.
So , in a nutshell what I tried to do was (assuming the amp is ok at 8 ohm), wire the Phillips in parallel with an 8 ohm load ( just another driver ) to make it about 16 ohm and wired that in parallel to the goodmans (15 ohm) which gave me a total of about 7- 8 ohms.
The problem was that the Phillips still showed it's claws on the HF when volume is pumped up a bit...
I am thinking I might have to get the Phillips up only play in the mids and lower somehow as well as making it look like a 15 or so OHM load( but without having to use a 3rd driver or contaminating it's sound quality) ,,, which I can then connect in parallel to the goodmans .
The reason why I think this is because I love the Goodmans as full range and just want the Phillips to bring along it's magical mids and sound low ( but not the screaming highs)...
Hope that makes sense though
.Tx again ( will let you know when I can have someone measure these amps and tell me exactly what they are capable of)...
T
Hope that makes sense though
Not that much
Consider that the load that only one speaker represents for the amplifier is a complex one; I guess you're playing with the sensations that each driver gives in contribution due to its diameter...it's called pistonic region in which the wavelenghts to be reproduced are related to the diameter and also the directivity index. So these are the very phisical things that happen when the coil is excited and the cone moves thereafter.
Then there's the electrical part of the speaker, which is just the coil...but also the magnet plays a role. Abruptely paralleling the coils of each speaker you make a more complex load, that's why you need to design first.
16 Ω coils are more efficient but require double power to play ( say, the same speaker with two types of coils...) at the same level than a 8 Ω speaker.
Some coils and caps for experimenting would be useful for making parallel or series crossovers. I would try to put the Axiom and the AD 8080 in some simple net...But none of them are supposed to sound good in multi-way as they are definitively full-range i.e. a sweet & correct voice band but nothing regarding modern hi-fi specifications
Sorry man.... For not making sense ...
Tx again ,,, seems like the answer is going to be that this us not a good idea then..
So , if I were to try simplify this plan ( just for my own understanding)
How would I get the Phillips ad12100 for example to only play upto a certain level ( somewhere just before HF's start) and stay away from the high frequency where I feel it's a bit too shouty/sharp...
I then want to put a cross to a good matched tweeter ... Lets say super tweeter to handle that HF from that point and make the load look like 15 ohm to the amp.
If I understand that , I could most probably apply the sane concept to my Goodmans , but in this case try leave the load at 15 ohms with the tweeter and in so doing have two OB's rather..
Tx again ,,, seems like the answer is going to be that this us not a good idea then..
So , if I were to try simplify this plan ( just for my own understanding)
How would I get the Phillips ad12100 for example to only play upto a certain level ( somewhere just before HF's start) and stay away from the high frequency where I feel it's a bit too shouty/sharp...
I then want to put a cross to a good matched tweeter ... Lets say super tweeter to handle that HF from that point and make the load look like 15 ohm to the amp.
If I understand that , I could most probably apply the sane concept to my Goodmans , but in this case try leave the load at 15 ohms with the tweeter and in so doing have two OB's rather..
I see now ( web search) that the Philips woofer ( huge )...well, let's call it fullrange, is available in 4 or 8 Ω versions, so you'd need a matching tweeter.
I would leave as they are. You said that you have Infinity woofers: those are modern ones that have enough excursion- see the surround roll that is more flexible than the double pledged cloth surround and it allows more...up and down! In the big cones the problem is that they don't behave very well above pistonic region, and flexibility of the cone don't make it behave very good;the treble are emitted from the very center, that's where the whizzer cone is located. So you'd need to move to much modern drivers if you want to hear good music in your room; the Goodmans are very good old school speakers but they have their limits; best thing you can do is pick the drivers with the same nominal impedance : I would use the Philips 12 " de-whizzered and even with some added mass only for bass, as the diameter may suggest...but it isn't designed to make high excursions needed for OB design. Find an 8Ω tweeter and start to cross it with a 1uF bipolar cap ( electrolytic ) or film.
In the sticky section in the Multy-way forum there's a topic explaining how to make crossovers by Allen B; in the 'Simple OB thread ( Manzanita )' started by
Pano you'll find useful informations when designing crossovers for OB- Not that OB is the perfect way of listening
I would leave as they are. You said that you have Infinity woofers: those are modern ones that have enough excursion- see the surround roll that is more flexible than the double pledged cloth surround and it allows more...up and down! In the big cones the problem is that they don't behave very well above pistonic region, and flexibility of the cone don't make it behave very good;the treble are emitted from the very center, that's where the whizzer cone is located. So you'd need to move to much modern drivers if you want to hear good music in your room; the Goodmans are very good old school speakers but they have their limits; best thing you can do is pick the drivers with the same nominal impedance : I would use the Philips 12 " de-whizzered and even with some added mass only for bass, as the diameter may suggest...but it isn't designed to make high excursions needed for OB design. Find an 8Ω tweeter and start to cross it with a 1uF bipolar cap ( electrolytic ) or film.
In the sticky section in the Multy-way forum there's a topic explaining how to make crossovers by Allen B; in the 'Simple OB thread ( Manzanita )' started by
Pano you'll find useful informations when designing crossovers for OB- Not that OB is the perfect way of listening
Thanks Pico.
Will read up on the reccomended info.
perfect way's of listening I do believe is very subjective.... lol
" must say , I will reccomend OB above all others anyday(maybe even hybrids, like Basszilla).
I got rid of my Branded gear very easily in favour of these.
Just had a listening session this past weekend to LEBEN amps , rhea and sme front end with vivid G1's and wow , very awesome, but I tell you, my OB's , for the price is just as special for me to listen to...
I am in search of musicality here, not the ussual audiphile tems , like detail and speed and tops and lows etc...
for my personal taste, I love the vintage drivers as is, just to get them not to play their weak sides(i.e the high on the philips) would be a plus"
Will read up on the reccomended info.
perfect way's of listening I do believe is very subjective.... lol
" must say , I will reccomend OB above all others anyday(maybe even hybrids, like Basszilla).
I got rid of my Branded gear very easily in favour of these.
Just had a listening session this past weekend to LEBEN amps , rhea and sme front end with vivid G1's and wow , very awesome, but I tell you, my OB's , for the price is just as special for me to listen to...
I am in search of musicality here, not the ussual audiphile tems , like detail and speed and tops and lows etc...
for my personal taste, I love the vintage drivers as is, just to get them not to play their weak sides(i.e the high on the philips) would be a plus"
Well, speaking of the first paragraphs in the Manzanita thread, Pano stretches a lot the concepts of sensitivity and efficiency.
So you may 'Kill' the sensitivity of the Philips 12" by putting a big coil ( around 5 mH -but also 10 mH !) before it so it would be playing only bass.
The Philips 8"-15 Ω crossed with a cap- so 1 st order for both drivers.
The 8 " would play half loud in normal conditions when compared with the 12"- remember the different impedances- but the 12" would still not reach its regime so they counter-balance- You may give it a try.ù
A simple calculator such the one available atStrassacker: Lautsprecher - Boxen - Selbstbau suggests a 22 uF capacitor for highpassing the 15 Ω Philips at 500 Hz
So you may 'Kill' the sensitivity of the Philips 12" by putting a big coil ( around 5 mH -but also 10 mH !) before it so it would be playing only bass.
The Philips 8"-15 Ω crossed with a cap- so 1 st order for both drivers.
The 8 " would play half loud in normal conditions when compared with the 12"- remember the different impedances- but the 12" would still not reach its regime so they counter-balance- You may give it a try.ù
A simple calculator such the one available atStrassacker: Lautsprecher - Boxen - Selbstbau suggests a 22 uF capacitor for highpassing the 15 Ω Philips at 500 Hz
Tx again picowall.
So are you saying the big coil in front of the philips 12" 8 ohm will make sure it only plays lower frequencies ?
then the 8" phillips with the 22uF cap will take care of the higher freq then...
So, just a question.. The 8" will then work as the uper mids and tweet and the 12"inch the lower side of the freq... ?
Do I wire the 8" and 12" in parallel to each other ? like in one of the Butterworth 1st order setups ?
What load do I expect to show to the ap in this setup ?
If so, i will try this.
Tx so much, at least some direction for me to go and try something.
So are you saying the big coil in front of the philips 12" 8 ohm will make sure it only plays lower frequencies ?
then the 8" phillips with the 22uF cap will take care of the higher freq then...
So, just a question.. The 8" will then work as the uper mids and tweet and the 12"inch the lower side of the freq... ?
Do I wire the 8" and 12" in parallel to each other ? like in one of the Butterworth 1st order setups ?
What load do I expect to show to the ap in this setup ?
If so, i will try this.
Tx so much, at least some direction for me to go and try something.
Yes, parallel type crossover is better as you can change on the fly some values.
Eg. you choose a 7 mH choke for the woofer ( maybe 2nd order is better ...but it depends also upon the placements of the drivers ) and start with 22 uF on the fullrange, then if you hear there's a dip between the two, you can put 33 uF instead. In the picture below, I show also a series connection: where (+) of one speaker goes to (-) of the other. Major trouble comes in the crossover region, where the outputs sum each other at -3dB (that's Butterworth) and the electrical phase is rotated +90° by the coil and - 90° by the capacitor, then there are the phase shifts introduced by the speaker themselves ( we care of the acoustical phase ! )..but for the impedance there are no problems as everything is designed and projected to perform well.
Eg. you choose a 7 mH choke for the woofer ( maybe 2nd order is better ...but it depends also upon the placements of the drivers ) and start with 22 uF on the fullrange, then if you hear there's a dip between the two, you can put 33 uF instead. In the picture below, I show also a series connection: where (+) of one speaker goes to (-) of the other. Major trouble comes in the crossover region, where the outputs sum each other at -3dB (that's Butterworth) and the electrical phase is rotated +90° by the coil and - 90° by the capacitor, then there are the phase shifts introduced by the speaker themselves ( we care of the acoustical phase ! )..but for the impedance there are no problems as everything is designed and projected to perform well.
Attachments
Ok .. Now I am confused again...
Pls bear with me.
I see you are now talking of a woofer then a full range...
So , I understood from the previous post(your second last one) that I must
1) take the Philips 12 inch 8 ohm fullrange , connect a coil in it from the positive coming from the amp,, negative straight to negative...This will make it play more low frequencies only and thereby get rid of the screaming highs...
2) Then take the philips 8 inch 15 ohm fullrange driver and connect a 22uf cap in it from the same positive as in 1 above coming from the amp and again the negative from the amp straight to this negative..
Ok. Now , did I miss something important here then..
Pls bear with me.
I see you are now talking of a woofer then a full range...
So , I understood from the previous post(your second last one) that I must
1) take the Philips 12 inch 8 ohm fullrange , connect a coil in it from the positive coming from the amp,, negative straight to negative...This will make it play more low frequencies only and thereby get rid of the screaming highs...
2) Then take the philips 8 inch 15 ohm fullrange driver and connect a 22uf cap in it from the same positive as in 1 above coming from the amp and again the negative from the amp straight to this negative..
Ok. Now , did I miss something important here then..
Lol...
I'd rather beg for help or try my own contraptions till I am happy..
Sorry for seeming to waste your time sire..
I did say upfront that I have no clue on these things.
Maybe I must hire someone that does have a clue and let them build the circuits for me rather then trying to understand myself .. I think it is too complicated for me now to waste time and other people's time for these basics.
Is there perhaps a "dummy" guide or DIY for dummies website you can recommend ?
I'd rather beg for help or try my own contraptions till I am happy..
Sorry for seeming to waste your time sire..
I did say upfront that I have no clue on these things.
Maybe I must hire someone that does have a clue and let them build the circuits for me rather then trying to understand myself .. I think it is too complicated for me now to waste time and other people's time for these basics.
Is there perhaps a "dummy" guide or DIY for dummies website you can recommend ?
That's how it goes.
The only ???? is the value of the coil, on which the other values are dependent...mostly the success of all the thingy ! You can try with a 4-5 mH coil, and bring over also some 22 uF/100uF bipolar electrolytics to try second order filter. You can fail only if you try ! Choke's wire diameter should be 1mm minimum ( see the resistance ...)
Hi Pico and all..
So last night( at least here in Sa was about 1am)...
After we spoke I connected the Philips Ad8080 15 ohm and connected simply in parallel to the goodmans axiom 201...
Wow , there was a clear difference in the sound , it seems like the two played well together and also the tops opened a bit more and the bass surprisingly also seemed deeper...
I obviously need to listen for a while and different music at different times before deciding anything... But... For now there is indeed a huge difference.. Just have to see if I like it enough...
Wonder why this would make such a big diff though...
Julian
So last night( at least here in Sa was about 1am)...
After we spoke I connected the Philips Ad8080 15 ohm and connected simply in parallel to the goodmans axiom 201...
Wow , there was a clear difference in the sound , it seems like the two played well together and also the tops opened a bit more and the bass surprisingly also seemed deeper...
I obviously need to listen for a while and different music at different times before deciding anything... But... For now there is indeed a huge difference.. Just have to see if I like it enough...
Wonder why this would make such a big diff though...
Julian
Hi Julian
The difference might be that you simply halved the total Z, so double SPL
and also you made the load correct for the 8Ω output transformer winding.
A higher SPL makes the sound richer.
I would really choose the multi way path, as now you are experiencing the
mechanical crossover given by the fact that a speaker has its own pass band.
By using specialized drivers for each band like woofers -midrange or tweeters
and the necessary network to make each working in the selected range.
A fullrange speaker- all of yours are fullrange- can be similar to a midrange i.e. limited to 100-10000 Hz and a descending slope at both ends.
It cannot compete with a 1" tweeter ( or even an old 3" paper cone tweeter )
because the wavelenghts ( to be reproduced) involved and the moving mass do not fit right. Same for the woofer, as the excursion needed to move a big mass of air is maximized in the design stage. Indeed, it's said that speaker design is a mean of compromises.
I would say to try the Philips 12"-8Ω ( without the whizzer cone and maybe later with some added mass, like a ring of solid copper wire glued in place of the whizzer ) and the 8"-15 Ω with the network(s) suggested.
The 12 " can be placed in an open back cabinet - sort of OB with lateral wings - and the 8" left alone with some acoustic (make some experiments
with natural wool, like pillow's internal etc. ) absorber on the back.
I still don't know if the sensitivities will match . Choose the choke for filtering the mid and treble out for the 12 " as bigger as you can, the sensitivity will decrease
I've been listening with a mono tube amp and a Goodmans 8"Axiette for the first 10 years of my life
The difference might be that you simply halved the total Z, so double SPL
and also you made the load correct for the 8Ω output transformer winding.
A higher SPL makes the sound richer.
I would really choose the multi way path, as now you are experiencing the
mechanical crossover given by the fact that a speaker has its own pass band.
By using specialized drivers for each band like woofers -midrange or tweeters
and the necessary network to make each working in the selected range.
A fullrange speaker- all of yours are fullrange- can be similar to a midrange i.e. limited to 100-10000 Hz and a descending slope at both ends.
It cannot compete with a 1" tweeter ( or even an old 3" paper cone tweeter )
because the wavelenghts ( to be reproduced) involved and the moving mass do not fit right. Same for the woofer, as the excursion needed to move a big mass of air is maximized in the design stage. Indeed, it's said that speaker design is a mean of compromises.
I would say to try the Philips 12"-8Ω ( without the whizzer cone and maybe later with some added mass, like a ring of solid copper wire glued in place of the whizzer ) and the 8"-15 Ω with the network(s) suggested.
The 12 " can be placed in an open back cabinet - sort of OB with lateral wings - and the 8" left alone with some acoustic (make some experiments
with natural wool, like pillow's internal etc. ) absorber on the back.
I still don't know if the sensitivities will match . Choose the choke for filtering the mid and treble out for the 12 " as bigger as you can, the sensitivity will decrease
I've been listening with a mono tube amp and a Goodmans 8"Axiette for the first 10 years of my life
I think you are playing,,,lol
Which Mark audio are you reccomending ?
The ones I've seen for OB is not even on 90 db sensitive.
If you have never tried a JELABS OB (exact to size) with a vintage like GOODMANS AXIOM 201 or Phillips AD12100 and valve amplification, then I think you must make time to do so...
The Marks will not come close and are about ten times the price I paid for either of these.
If you tried a JELABS, please let me know what your opinion was and what you thought of it.
The only speaker I've listened to in the last while was a VIVID GIYA G1 on LEBEN CS 1000P and perhaps the BASSZILLA(Eminence, fostex for mid and Arum Cantus tweeters) with trex VALVE BUILD that was in some ways more enjoyable then my single VINTAGE DRIVER JELABS OB,,,, bearing in mind , my amps are not in the class of Leben perhaps...
If you don;t mind... Please let me know your experience with OB of this nature and your opinion, I'd like to listen and perhaps consider some of the things you might mention before I continue further on this path perhaps.
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