Hi,
I'm glad you think the tweeter is good, I've not heard much about it, although it looks rather like some I've seen in commercial speakers - Ruark for example, might be a different one though.
Right, I'm going to go see what's inside, the only problem with that is, it's wired onto a PCB and I've not left enough wire to really take them out, so I can't see what's going on!! (one day it will go off-board and be wired point to point!)
I will at least be able to note down the values and exact number of components.
Will post more detail soon, and I really appreciate the advice!
-Simon
Oops! My mistake, I said "smaller, I think in parallel with tweeter." That should have read: smaller inductor, I think in parallel with tweeter.
I'm glad you think the tweeter is good, I've not heard much about it, although it looks rather like some I've seen in commercial speakers - Ruark for example, might be a different one though.
Right, I'm going to go see what's inside, the only problem with that is, it's wired onto a PCB and I've not left enough wire to really take them out, so I can't see what's going on!! (one day it will go off-board and be wired point to point!)
I will at least be able to note down the values and exact number of components.
Will post more detail soon, and I really appreciate the advice!
-Simon
Ahha! After much searching through German web sites (I don't speak German :-( ) I've found a .PDF file with some info on it.
http://www.tronicaudio.de/shop_e/files/bs_pontus.pdf
That has the x-over schematic and values, finally!!
The response curve for the speakers is pretty dam flat, which to me, doesn't help to explain the sound I hear, which simply isn't warm enough in the mids.
-Simon
http://www.tronicaudio.de/shop_e/files/bs_pontus.pdf
That has the x-over schematic and values, finally!!
The response curve for the speakers is pretty dam flat, which to me, doesn't help to explain the sound I hear, which simply isn't warm enough in the mids.
-Simon
SimontY said:
The NoFerro hasn't got ferrofluid in the airgap, so it is more sensitive for resonances, so I think it is a tweeter related problem.
Replacing the NoFerro with the Excel T25001 can be an option. Check also The Proteus It features the same drivers except the tweeter.
Ah, yes, I've seen the Proteus before, it looks nice.
Two Excel tweeters would cost me about £150, which I sadly can't afford right now, but maybe soon 😉 I must admit I have toyed with the idea before, I wonder if they'd fit the same mounting hole...
I guess the x-over would need re-jigging a little, maybe not too much?!? Hmm, just been looking and the Excel has a sensitivity of only 90db, whereas the noferro has 92db. I currently use a 1ohm resistor in series with the tweeter, I wonder if the Excel would work with no resistor... I bet that would sound nice!
Heh, just went and measured the old tweeter, 1cm smaller diameter 🙁
Ah well, next!
-Simon
Two Excel tweeters would cost me about £150, which I sadly can't afford right now, but maybe soon 😉 I must admit I have toyed with the idea before, I wonder if they'd fit the same mounting hole...
I guess the x-over would need re-jigging a little, maybe not too much?!? Hmm, just been looking and the Excel has a sensitivity of only 90db, whereas the noferro has 92db. I currently use a 1ohm resistor in series with the tweeter, I wonder if the Excel would work with no resistor... I bet that would sound nice!
Heh, just went and measured the old tweeter, 1cm smaller diameter 🙁
Ah well, next!
-Simon
Rising response
Simon,
Looking at the kit manufacturer's graphs, it appears the tweeter has a rising response >5khz. This is not uncommon for Seas tweeters.
Try parallelling a 1uF cap to flatten the response. If this is not sufficient, go to 2uF.
Cheers,
M
Simon,
Looking at the kit manufacturer's graphs, it appears the tweeter has a rising response >5khz. This is not uncommon for Seas tweeters.
Try parallelling a 1uF cap to flatten the response. If this is not sufficient, go to 2uF.
Cheers,
M
Another quick thing you could try is to angle them differently in order to compensate for the rising response.
Regards
Charles
Regards
Charles
Hello Simon,
Ooops, those images are a bit big - I am learning Photoshop just tonight.....
Anyway, the impedence curve shows a pretty big hump at around 1350 Hz or so.
This can represent excessive sensitivity around this frequency.
The cure is a series resonant circuit across the box or particular driver (tweeter ?) that dumps energy in this band.
Rightmark Audio Analyser (free download) can be used to obtain impedence sweeps of the mounted drivers with a suitable soundcard and external jig.
With the crossover network mounted externally and access to the wires going to the drivers, you can modify and measure changes with this software.
There are Java calculators on the net to help you calculate component values.
My first move would be to quench that mid hump at the tweeter and hear what you get.
This impedence compensation can affect the required crossover values.
You can under or over compensate the individual drivers and then tweak the crossover values to dial in whatever sound you want.
This takes time and repeated trials and measurements, but you should be able to cure many ills, and tune into your preferred sound.
Eric.
Ooops, those images are a bit big - I am learning Photoshop just tonight.....
Anyway, the impedence curve shows a pretty big hump at around 1350 Hz or so.
This can represent excessive sensitivity around this frequency.
The cure is a series resonant circuit across the box or particular driver (tweeter ?) that dumps energy in this band.
Rightmark Audio Analyser (free download) can be used to obtain impedence sweeps of the mounted drivers with a suitable soundcard and external jig.
With the crossover network mounted externally and access to the wires going to the drivers, you can modify and measure changes with this software.
There are Java calculators on the net to help you calculate component values.
My first move would be to quench that mid hump at the tweeter and hear what you get.
This impedence compensation can affect the required crossover values.
You can under or over compensate the individual drivers and then tweak the crossover values to dial in whatever sound you want.
This takes time and repeated trials and measurements, but you should be able to cure many ills, and tune into your preferred sound.
Eric.
Hi all,
Thanks for the excellent advice everyone, you've given me some great and useful pointers!
mhb, I will try putting a cap right across the tweeter terminals, as this is quite easy to do, I hope this is what you had in mind.
Charles, it would be true to say I've not experimented with positioning much at all in my curent listening room, I will tinker...
Eric, you've mentioned some good ideas there, although I am a little lost in where to start! I suppose downloading that software is the way to go to begin with... And yeh, the speakers are cool-looking! Mine don't really look like that yet, ahem. Not painted them, never been able to disconnect them for more than a few minutes at a time, so they must be doing something right!!!
Once again thanks all!
-Simon
Thanks for the excellent advice everyone, you've given me some great and useful pointers!
mhb, I will try putting a cap right across the tweeter terminals, as this is quite easy to do, I hope this is what you had in mind.
Charles, it would be true to say I've not experimented with positioning much at all in my curent listening room, I will tinker...
Eric, you've mentioned some good ideas there, although I am a little lost in where to start! I suppose downloading that software is the way to go to begin with... And yeh, the speakers are cool-looking! Mine don't really look like that yet, ahem. Not painted them, never been able to disconnect them for more than a few minutes at a time, so they must be doing something right!!!
Once again thanks all!
-Simon
Mr Pass,
Why not give me one of your amps, for free? I'll tell you if my problem goes away 😉
Seriously though, I don't blame my amp at all for this sound, maybe for a little lack of excitement and the last ounce of everything. It's a fine amp though, the speakers make my sound what it is, I believe.
-Simon
Why not give me one of your amps, for free? I'll tell you if my problem goes away 😉
Seriously though, I don't blame my amp at all for this sound, maybe for a little lack of excitement and the last ounce of everything. It's a fine amp though, the speakers make my sound what it is, I believe.
-Simon
First Things First........
Hi Simon,
The first thing to do is to get you upstream system sound ing decent in the first case, and then devote efforts to the speakers.
What equipment and cables are you using ?.
Eric.
Hi Simon,
The first thing to do is to get you upstream system sound ing decent in the first case, and then devote efforts to the speakers.
What equipment and cables are you using ?.
Eric.
Hi Eric,
My system upstream is good, but perhaps lacking in synergy, particularly with these speakers! Ok, here it is:
Source: Marantz CD63KI with 20+ small to large mods
Interconnect: Kimber Crystal-Cu (pure copper, 4 way braid, teflon)
Amp: Roksan Caspian integrated, (supposedly Mk2, like it matters) -psu increased to ~30,000uf; other tiny mods
Cables: DNM Reson bi-wired, bare-wired@amp + Neutrik@speakers, w/ferrite rings (Reson is solid core cu. with tefon)
Sub: Adire Tempest (15") in 260litre (EBS alignment) driven by 150w plate amp with added capacitance (system is cold as ice without the sub, almost tinny!) (f3=<20hz)
Mains: amp power comes through 2kva iso. transformer, I also have plenty of parallel caps and varistors around the system
Support: 18mm MDF shelves on threaded steel bolts, spiked to concrete floor, no added mass: tried it, and it got muddy... Amp and CDP sit on 3 oak cone feet each (much better than the standard feet!)
It will take someone with uber-system-knowledge to tell me what is lacking just from reading the description! Eric, I think you could have a good go 🙂
My only concern is the speaker cable, it's thin! I want to try Kimber here, I reckon it may suit my tastes/system more...
-Simon
My system upstream is good, but perhaps lacking in synergy, particularly with these speakers! Ok, here it is:
Source: Marantz CD63KI with 20+ small to large mods
Interconnect: Kimber Crystal-Cu (pure copper, 4 way braid, teflon)
Amp: Roksan Caspian integrated, (supposedly Mk2, like it matters) -psu increased to ~30,000uf; other tiny mods
Cables: DNM Reson bi-wired, bare-wired@amp + Neutrik@speakers, w/ferrite rings (Reson is solid core cu. with tefon)
Sub: Adire Tempest (15") in 260litre (EBS alignment) driven by 150w plate amp with added capacitance (system is cold as ice without the sub, almost tinny!) (f3=<20hz)
Mains: amp power comes through 2kva iso. transformer, I also have plenty of parallel caps and varistors around the system
Support: 18mm MDF shelves on threaded steel bolts, spiked to concrete floor, no added mass: tried it, and it got muddy... Amp and CDP sit on 3 oak cone feet each (much better than the standard feet!)
It will take someone with uber-system-knowledge to tell me what is lacking just from reading the description! Eric, I think you could have a good go 🙂
My only concern is the speaker cable, it's thin! I want to try Kimber here, I reckon it may suit my tastes/system more...
-Simon
"I have 'revealing' speakers and listen to all types of music, I experience this harsh upper-mid/lower-treble glare on nearly half the music I play, and on most of the rest if I turn it up loud enough!"
"........ I still have a white glare on many vocals and 'screaming' electric guitars really scream - it hurts, literally."
Hi Simon,
Thanks for the compliment, ........errr, or was that a challenge....
I can see that you have spent a fair bit on what you have, and I am not out to insult you.
I had a listen to a Roksan amp like yours and Roksan cdp a while back.
My impressions after extended listen that I was not in love with it.
I found it to sound a little light/thin/cold and slightly bass shy in the English tradition.
Quite nicely detailed and not a bad amp, just a bit light sounding for me, and I did pickup on a touch of highs false brightnesss.
I made up a pair of Kimber interconnect cables for a dealer friend yesterday (3 wires, red, black, blue, teflon) but I have not heard them yet.
I have heard ones the same on a big Parasound amp and electrostatics though.
I find teflon adds a particular mids and highs hardness character, almost rattly/crackly nuance and I heard this on the above system.
This was a very very nice system, and this character was not particularly troublesome, but it was there.
I don't use teflon cables for this reason.
The speaker cable that you have due to the conductor spacing will be relatively highly inductive.
I find this can give a hardness to mids and highs, and bass is not as big as should be.
Sonic manifestations can be zedding on female vocals, and tishing on cymbals etc.
Conductance is not as big an issue as Monster Cable would have you believe, but loop inductance is.
I use 10 pair (or 20 pair) indoor telephone cable - this gives a cable of virtually zero inductance, and plenty of copper conductance, and is cheap, even free.
Compared to other cables, I get more solid and lower bass, more intelligble vocals, cleaner highs/tops and a more direct but at the same time more relaxed presentation, but still plenty of detail.
I have used it for a long time and it is my preferred choice.
The isolation transformer is usually a good thing, but be carefull with shunt capacitors because they can set up ringing conditions - RC snubbers are what is required.
I have also found varistors to add a mids funny harshness/dirt so not recomended in my experience.
Also beware of adding low value shunt capacitances in internal power supplies too, as this can set up further ringing conditions within equipment, and this can manifest as an edginess and overlybright/false detail presentation.
I would try different speaker cables for a start to get the edginess down before sorting the speakers.
Silicone insulated power leads can be a big help, and the polarity of the AC mains into each component can have a big effect too.
One day I will fit mains polarity reversing switches to my gear.
From what you describe, it seems that you have an overly 'detailed' system, coupled to speakers with an impedence hump in the vocals (1350 Hz).
This sounds like a tinnitus inducing combination in my experience.
A series RLC network across the tweeter will tame its resonance, and an additional RC network across the tweeter will tame its tops.
Once you have done this you may find that the woofers sound out of character wrt the tweeters, and they may require the same treatment - mainly RC network to calm the tops of the woofer - the bass resonance can be usefull, but can be controlled with a shunt RLC network.
After do have done this you will likely neeed to adjust the crossover points.
As I said you can over damp or under damp any of these four networks and thereby 'voice' your speaker, and this is where a lot of time can go.
Having the crossover externally mounted is a big help, as is modifying each of the boxes in stages so that you have reference points.
This is a start, hope it helps.
If you need more info just ask.
Eric.
"........ I still have a white glare on many vocals and 'screaming' electric guitars really scream - it hurts, literally."
Hi Simon,
Thanks for the compliment, ........errr, or was that a challenge....
I can see that you have spent a fair bit on what you have, and I am not out to insult you.
I had a listen to a Roksan amp like yours and Roksan cdp a while back.
My impressions after extended listen that I was not in love with it.
I found it to sound a little light/thin/cold and slightly bass shy in the English tradition.
Quite nicely detailed and not a bad amp, just a bit light sounding for me, and I did pickup on a touch of highs false brightnesss.
I made up a pair of Kimber interconnect cables for a dealer friend yesterday (3 wires, red, black, blue, teflon) but I have not heard them yet.
I have heard ones the same on a big Parasound amp and electrostatics though.
I find teflon adds a particular mids and highs hardness character, almost rattly/crackly nuance and I heard this on the above system.
This was a very very nice system, and this character was not particularly troublesome, but it was there.
I don't use teflon cables for this reason.
The speaker cable that you have due to the conductor spacing will be relatively highly inductive.
I find this can give a hardness to mids and highs, and bass is not as big as should be.
Sonic manifestations can be zedding on female vocals, and tishing on cymbals etc.
Conductance is not as big an issue as Monster Cable would have you believe, but loop inductance is.
I use 10 pair (or 20 pair) indoor telephone cable - this gives a cable of virtually zero inductance, and plenty of copper conductance, and is cheap, even free.
Compared to other cables, I get more solid and lower bass, more intelligble vocals, cleaner highs/tops and a more direct but at the same time more relaxed presentation, but still plenty of detail.
I have used it for a long time and it is my preferred choice.
The isolation transformer is usually a good thing, but be carefull with shunt capacitors because they can set up ringing conditions - RC snubbers are what is required.
I have also found varistors to add a mids funny harshness/dirt so not recomended in my experience.
Also beware of adding low value shunt capacitances in internal power supplies too, as this can set up further ringing conditions within equipment, and this can manifest as an edginess and overlybright/false detail presentation.
I would try different speaker cables for a start to get the edginess down before sorting the speakers.
Silicone insulated power leads can be a big help, and the polarity of the AC mains into each component can have a big effect too.
One day I will fit mains polarity reversing switches to my gear.
From what you describe, it seems that you have an overly 'detailed' system, coupled to speakers with an impedence hump in the vocals (1350 Hz).
This sounds like a tinnitus inducing combination in my experience.
A series RLC network across the tweeter will tame its resonance, and an additional RC network across the tweeter will tame its tops.
Once you have done this you may find that the woofers sound out of character wrt the tweeters, and they may require the same treatment - mainly RC network to calm the tops of the woofer - the bass resonance can be usefull, but can be controlled with a shunt RLC network.
After do have done this you will likely neeed to adjust the crossover points.
As I said you can over damp or under damp any of these four networks and thereby 'voice' your speaker, and this is where a lot of time can go.
Having the crossover externally mounted is a big help, as is modifying each of the boxes in stages so that you have reference points.
This is a start, hope it helps.
If you need more info just ask.
Eric.
Eric,
Wow! What an analysis that was, I'm pleased with that. I certainly don't take your comments as insulting because by and large you've accurately described the sound 'issues' I have and have had in the recent past.
It's a small point, but I've experienced no negatives really from using caps across live and neutral in my cd player and in add-on parallel filters - one I made, one I bought. I found increased richness and sweeter treble, but this is/was not enough to cure the real ills.
I find your analysis of the speaker cable to be particularly interesting. Because I use Nuetrik Speakons it's a pain to try others, and I have not done so since building these speakers. I do actually have some cheap Kimber - 4PR - which a mate has right now - I will get that back and try it out, see what happens.
Another friend had a Roksan amp (Kandy this time, cheaper and rougher with loads of power - I used to have one!). But guess what? His system is sweet, smooth and so relaxed you could fall asleep to loud Metallica, really! He used a CD67OSE (I think this is warm in itself), Kimber speaker cable, Kimber Tonik IC (copper, not teflon...), we wired his speakers internally with the same Kimber speaker cable. His speakers are IPL transmission line kits. Lovely system for little money, and now that he can't hear me say it - much more musical than mine was!!! (if not as detailed or 'clean')
The reason I mention my friend's system I suppose is because for me it's a lesson in system synergy. His system was so lush it verged on being boring, and mine was so etched and clinical it wasn't much fun at all! It's not as bad now, but still, it ain't perfect.
Your comments Eric, have inspired me enough to spend my next pay on some Kimber speaker cable, or at least to try my cheap Kimber first, if I can get 'em back off Hairy John... If this is positive, I will go through the trauma (believe me, the way we built these things, it's gonna be TRAUMA!!) of taking my x-overs out of the box and wiring internals with whatever I use for my amp-speaker runs. A hi-fi friend swears by using the same speaker cable from amp>speakers and inside the speakers, and who am I to argue?
Many, many thanks, I'd buy you a drink if you were local 😉
-Simon
Wow! What an analysis that was, I'm pleased with that. I certainly don't take your comments as insulting because by and large you've accurately described the sound 'issues' I have and have had in the recent past.
It's a small point, but I've experienced no negatives really from using caps across live and neutral in my cd player and in add-on parallel filters - one I made, one I bought. I found increased richness and sweeter treble, but this is/was not enough to cure the real ills.
I find your analysis of the speaker cable to be particularly interesting. Because I use Nuetrik Speakons it's a pain to try others, and I have not done so since building these speakers. I do actually have some cheap Kimber - 4PR - which a mate has right now - I will get that back and try it out, see what happens.
Another friend had a Roksan amp (Kandy this time, cheaper and rougher with loads of power - I used to have one!). But guess what? His system is sweet, smooth and so relaxed you could fall asleep to loud Metallica, really! He used a CD67OSE (I think this is warm in itself), Kimber speaker cable, Kimber Tonik IC (copper, not teflon...), we wired his speakers internally with the same Kimber speaker cable. His speakers are IPL transmission line kits. Lovely system for little money, and now that he can't hear me say it - much more musical than mine was!!! (if not as detailed or 'clean')
The reason I mention my friend's system I suppose is because for me it's a lesson in system synergy. His system was so lush it verged on being boring, and mine was so etched and clinical it wasn't much fun at all! It's not as bad now, but still, it ain't perfect.
Your comments Eric, have inspired me enough to spend my next pay on some Kimber speaker cable, or at least to try my cheap Kimber first, if I can get 'em back off Hairy John... If this is positive, I will go through the trauma (believe me, the way we built these things, it's gonna be TRAUMA!!) of taking my x-overs out of the box and wiring internals with whatever I use for my amp-speaker runs. A hi-fi friend swears by using the same speaker cable from amp>speakers and inside the speakers, and who am I to argue?
I think this is a fair description, it sounds like you've heard it!!!
Many, many thanks, I'd buy you a drink if you were local 😉
-Simon
Don't Spend Silly Money.........Trust me.
Hi Simon,
Your friends advice of running the same cable to the speakers and also inside the cabinets is one that works very nicely - adds a coherence (or removes incoherence) that you cannot get otherwise.
Be sure to make all cable runs in the same direction though or you will compromise this coherence.
Savadamunney and go for 10 pair indoor telephone cable - here in Aus it costs only AUS$1.00 per metre from electrical trade suppliers.
If you don't like it the cost penalty is slight, but I am sure that you will like it.
The interconnects I just made cost AUS$120.00 for 3 metres of cable plus connectors - very expensive in my books - cheaper cable is not always bad.
I meant that teflon insulation adds a hardness, and I hear it as a distinct character whenever I have heard it used.
Ditch the neutriks and use banana biding posts - the cheap gold ones are sonically perfectly fine enough.
"with an impedence hump in the vocals (1350 Hz).
That can represent an increase in efficiency in that band - either way it means that the amp is having to deal with reflected energy in that band, and you don't want artifacts appearing - cure that hump.
Must fly - customer coming.
Cheers, Eric.
Thanks for the offer of a drink.
Hi Simon,
Your friends advice of running the same cable to the speakers and also inside the cabinets is one that works very nicely - adds a coherence (or removes incoherence) that you cannot get otherwise.
Be sure to make all cable runs in the same direction though or you will compromise this coherence.
Savadamunney and go for 10 pair indoor telephone cable - here in Aus it costs only AUS$1.00 per metre from electrical trade suppliers.
If you don't like it the cost penalty is slight, but I am sure that you will like it.
The interconnects I just made cost AUS$120.00 for 3 metres of cable plus connectors - very expensive in my books - cheaper cable is not always bad.
I meant that teflon insulation adds a hardness, and I hear it as a distinct character whenever I have heard it used.
Ditch the neutriks and use banana biding posts - the cheap gold ones are sonically perfectly fine enough.
"with an impedence hump in the vocals (1350 Hz).
That can represent an increase in efficiency in that band - either way it means that the amp is having to deal with reflected energy in that band, and you don't want artifacts appearing - cure that hump.
Must fly - customer coming.
Cheers, Eric.
Thanks for the offer of a drink.
Hi,
1 - Won't it add graininess, now that I am used to 'quality' cable?
2 - Does 10pair refer to the type as it comes off the reel, or the fact you've run 10 pairs of conductors together??
3 - Also, yes you may pull a face here 😉 - but what about geometry? I'm really keen on using braiding or at least twisting to reduce RFI. I do not, however, wish to repeat the nightmare of making 54-conductor CAT-5 cables, as I tried once (it got too short and took weeks - it's now a nice power lead for my cdp)
I will get the x-over out of the box as soon as possible, though free time seems to have dimished severely now that I'm no longer a student 🙁
Obviously, x-over out of the box will make it infinitely easier to tinker, but will it also improve the sound, as I hope?
Cheers again,
-Simon
Yeh, I understood 🙂 (and I don't disagree!)
I'm sure that's exactly what he said too!
This is an interesting idea, but I have 2 questions..:
1 - Won't it add graininess, now that I am used to 'quality' cable?
2 - Does 10pair refer to the type as it comes off the reel, or the fact you've run 10 pairs of conductors together??
3 - Also, yes you may pull a face here 😉 - but what about geometry? I'm really keen on using braiding or at least twisting to reduce RFI. I do not, however, wish to repeat the nightmare of making 54-conductor CAT-5 cables, as I tried once (it got too short and took weeks - it's now a nice power lead for my cdp)
I will get the x-over out of the box as soon as possible, though free time seems to have dimished severely now that I'm no longer a student 🙁
Obviously, x-over out of the box will make it infinitely easier to tinker, but will it also improve the sound, as I hope?
Cheers again,
-Simon
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