AudioCircle
Industry Circles => Sonic Craft => Topic started by: OSIB16 on 18 Oct 2018, 03:54 pm
-
Hi Jeff,
I’m building a music and home cinema system using classic B&O BEOVOX 100 loudspeakers from the early 1990’s. They are wonderful and classy with their solid aluminium cabinets.
I would like to upgrade the internal components to Mundorf Silver/Oil and Neotech Copper hookup wire. It appears to be a very simplistic design, judging by the photos below. There is a Bipolar Capacitor that has the following ratings...
6u8
63v
137 Phillips
Please advise me which parts I need to buy from yourself, so that I can proceed with placing an order. :popcorn:
-
(https://www.audiocircle.com/image.php?id=185600)
(https://www.audiocircle.com/image.php?id=185601)
-
(https://www.audiocircle.com/image.php?id=185612)
-
(https://www.audiocircle.com/image.php?id=185613)
-
(https://www.audiocircle.com/image.php?id=185614)
-
Did they really put a piece of foam over the tweeter???!!! HOLY ---- that's a huge amount of deadening. Perhaps they are using the foam to drop the high end??? Never seen that before, except for some old JBL's.
First, get some foam and tweek with cutouts to find out what they were doing. If you must have covers rig some cloth over it and cut out the area in front of the drivers at 45* angling out.
This will make 10x more difference than changing crossover components. But if you must, replace the electrolytic cap. Honestly, I think you are trying to make this into something it's not... a high quality speaker. But you could upgrade to an inexpensive poly or mylar cap and get some improvement over the electrolytic. I'd be reluctant to put $$ into higher quality for this speaker.
-
Not much in the way of visible markings on the components but they will need to be measured to have Jeff or someone help with component choices.
On a side note, Danny of GR research is offering free crossover designing so if you can send him one original speaker he could find a better solution than just swapping parts.
-
SClark,
Its not foam. It is a boxed plastic frame with thin acoustic fabric wrapped over it.
-
JakeJ,
Because this speaker is a basic D’Apolitino design with 2 bass/mid drivers sandwiching a single tweeter, I thought maybe Jeff could help me start from scratch somehow.
-
SClark,
Its not foam. It is a boxed plastic frame with thin acoustic fabric wrapped over it.
Well, the photos sure fooled me. So ignore everything I said except to swap that capacitor for something a bit better. I'd bet it's a 6.8 uF cap at 63V. Any decent poly cap should do a better job, won't cost an arm and a leg, and will give you some idea if you need to go further. As someone mentioned, Danny would design a crossover for free, and no one could make it sound better, but he doesn't use cheap parts. One advantage is that you only have one crossover to build.
-
(https://www.audiocircle.com/image.php?id=185612)
The acoustic internal treatment are poor try this:
https://www.audiocircle.com/index.php?topic=100689.0
-
Thanks for the heads up SClark, I’ll bear that in mind. A 6.8uf Mundorf capacitor would probably be so large that it wouldn’t fit inside the speaker cabinet. Instead perhaps I should just replace the internal wire with some cotton covered Neotech wire (this made a significant difference on my Monitor Audio Radius). However I did find the following interesting info about the CX100 on a Dutch website...
Re: BEOVOX CX100 filter???
door adijk » di 12 feb 2013, 18:32
Kleine aanvulling over wat ik op het net heb gevonden:
"The bottom woofer is connected in series with a a coil, as expected. The top woofer however, is connected in series with this coil and another coil that is paralleled with a capacitor. A weird thing about this second coil is that it has an iron core, just like a transformer. I thought this led to unlinearities.
The tweeter is connected in series with the lower woofer and bypassed by the first coil and also in series with the upper woofer - coil/capacitor combination.
I suppose the coil/capacitor is a bandstop filter. In conjunction with the other coil it will probably attenuate all frequencies exept the lower bass range to the top woofer. And the tweeter must in some way be affected too, but it is unclear how. It is clear however, that the two woofers will not have the same frequency response."
-
Fullrangeman,
Thanks for that info, however I am already of the same mind as yourself when it comes to internal damping.
-
@OSIB16 - Those are nice-looking speakers.
I was surprised to see some Dutch in the text. Let me know if you need help in translation.
Dutch in DC....
-
At Jeff's web site he shows a 6.8 Sonicap at $17 that should provide better detail. I'd do that before changing wiring- usually caps make a bigger difference than wire. Also, it should fit with room to spare.
-
17 dollars? Damn thats cheap. I wonder if it’s Bipolar.
-
17 dollars? Damn thats cheap. I wonder if it’s Bipolar.
It's a crossover cap, so it's non polar. I can't think of a case where a crossover cap is polar.
The word on Sonicap is that they lean toward detail/analytical where Mundorfs are perhaps fuller and more musical... but this is a center channel. It's mostly about clarity of the spoken voice. Clean and detailed is what I would want in that position. But email Jeff and ask him if he doesn't chime in here soon.
-
SClark, its not a centre speaker, I merely turned it on its side for easier access to the inside. This is a hifi stereo speaker which comes as a pair. If you read that excerpt I took from a Dutch website, it explains that there is significant amount of filtering within the circuit design; which attenuates the treble and midrange at higher volume levels. I think that this may be detrimental to the transparency capabilities of this speaker. Can’t get hold of Jeff unfortunately.
-
Dan,
Thank you for contacting me direct. Since I do not use this site like others, I'm not constantly checking in. :(
As I had guessed, it is a 2.5 way series network. And, as I had mentioned, your plan to mount the front three on their sides is flawed due to their intended dispersion.
Any attempt to convert them to a MTM is flawed because the two 4" drivers are different, so removing the large coil, and reducing the value of the smaller coil is not recommended.
You could try adjusting the toe in/out on the L/R for best results (prior to modification). The L/R would need to be mirror imaged whether mids were in or out. However, I just have a hard time seeing the center working out. The angled face plate will likely be working against you as well.
If the front three were mounted vertical, I would still need a description of what you felt lacking before making parts recommendations. The electrolytic would have to be replaced, but an air core replacement for the small coil would depend.
-
Jeff,
OK so I have no choice but to use the CX100 in a vertical dispersion configuration. I will not turn them over onto their sides. As for my opinion of the sound quality of these speakers in an unmodified state; I mostly agree with your assesment over the telephone where you described the sonic signature as mostly Neutral, but with a slightly soft treble. However I do not agree that they are laid back. To my ears they are not Laidback and they are not Forward. I would class them as walking the fine tightrope between the two. You also critiqued them as lacking in Dynamics.
-
Ok so for the Beovox CX100 I would like the modifications to achieve the following...
1) Improvement in Dynamics.
2) Slightly better treble extension (less roll off).
3) No reduction in bass.
4) More bass would be welcomed (please advise me on fitting bass reflex tube or tubes).
5) Greater increase in transparency.
6) Greater increase in 3d holographic imaging.
Finally please recommend which hookup wire I need to purchase from you to completely rewire them internally.
-
Ok so for the Beovox CX100 I would like the modifications to achieve the following...
1) Improvement in Dynamics.
2) Slightly better treble extension (less roll off).
3) No reduction in bass.
4) More bass would be welcomed (please advise me on fitting bass reflex tube or tubes).
5) Greater increase in transparency.
6) Greater increase in 3d holographic imaging.
Finally please recommend which hookup wire I need to purchase from you to completely rewire them internally.
IOW, you want to:
-reengineer the crossover (NOT just play the same circuit, fancy parts game - that kind of deaf-man's game won't get you ANYWHERE towards your goals)
-possibly upgrade the drivers
-perhaps brace (or damp) the cabinet a bit.
Hasn't B&O released some sort of active modernization for these speakers? You know, REAL potential improvements: streaming into DSP controller into multiple tailored amplifiers.
"Hookup wire" won't get you anywhere near your goals.
-
Yep, realizing what he wants to accomplish from a set of mid fi B&O speakers, the best bet is to send one to Danny and have him design a crossover. The parts will not be cheap, but not exorbitant, and you'll get the absolute most from the drivers and cabinet. A cap and some wire isn't going to get it done.
-
We need to remember that I am intending to use these speakers for a home cinema (not a state of the art 2 channel hifi). Secondly; they are still damn good sounding speakers for hifi use, even before the modifications (equivalent to $1000 modern day monitors). I am simply looking to give them a significant boost in movie playback performance through Jeff’s modification suggestions. My aim is to get a realistic cinema sound.
-
OK, best of luck.
-
Thanks I'm looking forward to the end result.
-
Jeff,
OK so I have no choice but to use the CX100 in a vertical dispersion configuration. I will not turn them over onto their sides. As for my opinion of the sound quality of these speakers in an unmodified state; I mostly agree with your assesment over the telephone where you described the sonic signature as mostly Neutral, but with a slightly soft treble. However I do not agree that they are laid back. To my ears they are not Laidback and they are not Forward. I would class them as walking the fine tightrope between the two. You also critiqued them as lacking in Dynamics.
My apologies for my miscommunication. I was expressing that your speaker would lean towards the relaxed side ("laid back"), and be a bit wanting for dynamics when used for an HT. Of course, we are getting down to opinions and taste here. However, you seemed to agree with the rest of my assessment. Since you are willing to stand them upright, I'm willing to make a parts recommendation that will lean towards your desired result.
1, 2, 3, 5, and 6) Replace C1 with a http://www.soniccraft.com/product_info.php/gen-sonicap-68-uf-200vdc-p-443 (http://www.soniccraft.com/product_info.php/gen-sonicap-68-uf-200vdc-p-443), and confirm the small coil is an air core.
4) Increased output in the bottom two octaves will not be improved with a modified alignment. At least not for what you are after. Your 4" drivers are just not capable of moving the air at volume. This will require special attention to your sub selection.
Replace the Purple and White wire with http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-red-p-1879 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-red-p-1879)/http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-white-p-1582 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-white-p-1582). Replace the Yellow and Orange wire with http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-teflon-18-awg-red-p-1580 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-teflon-18-awg-red-p-1580). Replace the Black and Red with http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-pvc-16-awg-yellow-p-1591 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-pvc-16-awg-yellow-p-1591). Solder the terminal side of the cap directly to the input terminal "without" jumpering off the large coil. At the same time, solder the new 16ga wire that replaces the old Black wire to the same terminal. Leave enough lead on the terminal side of the cap to solder the new 18ga wire that replaces the old Yellow wire. You do not want to solder the wire right next to the cap. You want enough lead to place a heat sink between the joint and the cap if necessary. Solder the 18ga replacement for the Orange wire to the tinned part of the lead on the small coil just before it connects to the larger coil. Solder the 23ga White wire replacement directly to the appropriate side of the cap like you did with the 18ga on the other end of the cap.
Clean your solder joints well before and after. Make good mechanical connections before making good solder joints. Shorter lengths of wire is usually better, but leave enough slack for unstrained assembly. Further, I would leave/add the necessary 8-12% of length to make a twisted pair of the two leads that go to the tweeter, and the 18ga leads going to the mid. Lastly, be sure you have marked and followed proper polarity.
-
My apologies for my miscommunication. I was expressing that your speaker would lean towards the relaxed side ("laid back"), and be a bit wanting for dynamics when used for an HT. Of course, we are getting down to opinions and taste here. However, you seemed to agree with the rest of my assessment. Since you are willing to stand them upright, I'm willing to make a parts recommendation that will lean towards your desired result.
1, 2, 3, 5, and 6) Replace C1 with a http://www.soniccraft.com/product_info.php/gen-sonicap-68-uf-200vdc-p-443 (http://www.soniccraft.com/product_info.php/gen-sonicap-68-uf-200vdc-p-443), and confirm the small coil is an air core.
4) Increased output in the bottom two octaves will not be improved with a modified alignment. At least not for what you are after. Your 4" drivers are just not capable of moving the air at volume. This will require special attention to your sub selection.
Replace the Purple and White wire with http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-red-p-1879 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-red-p-1879)/http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-white-p-1582 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-silver-in-teflon-23-awg-white-p-1582). Replace the Yellow and Orange wire with http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-teflon-18-awg-red-p-1580 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-teflon-18-awg-red-p-1580). Replace the Black and Red with http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-pvc-16-awg-yellow-p-1591 (http://www.soniccraft.com/product_info.php/neotech-solid-upocc-copper-in-pvc-16-awg-yellow-p-1591). Solder the terminal side of the cap directly to the input terminal "without" jumpering off the large coil. At the same time, solder the new 16ga wire that replaces the old Black wire to the same terminal. Leave enough lead on the terminal side of the cap to solder the new 18ga wire that replaces the old Yellow wire. You do not want to solder the wire right next to the cap. You want enough lead to place a heat sink between the joint and the cap if necessary. Solder the 18ga replacement for the Orange wire to the tinned part of the lead on the small coil just before it connects to the larger coil. Solder the 23ga White wire replacement directly to the appropriate side of the cap like you did with the 18ga on the other end of the cap.
Clean your solder joints well before and after. Make good mechanical connections before making good solder joints. Shorter lengths of wire is usually better, but leave enough slack for unstrained assembly. Further, I would leave/add the necessary 8-12% of length to make a twisted pair of the two leads that go to the tweeter, and the 18ga leads going to the mid. Lastly, be sure you have marked and followed proper polarity.
Ok Jeff. Yes the small coil is definitely an ‘Air Core Inductor’.
I would just like to confirm your directions. Please correct me if I am wrong...
1) REMOVE THE OLD RED WIRE SOLDERED ONTO THE MIDDLE TAB OF THE LARGE COIL. REPLACE IT WITH RED NEOTECH 16AWG WIRE.
2) BOTH LEADS OF THE SONICAP GEN I ARE NOT SOLDERED ONTO THE TABS OF THE LARGE COIL.
3) SOLDER THE WHITE NEOTECH 23AWG WIRE ONTO THE END OF THE SONICAP LEAD.
4) THE PURPLE NEOTECH 23AWG WIRE IS SOLDERED DIRECTLY ONTO THE POSITIVE INPUT TERMINAL.
Please confirm...
-
1) Almost... "REPLACE IT WITH (YELLOW) NEOTECH 16AWG WIRE".
2) It should be soldered to the Left side of the large coil where the White and Orange wire are presently connected.
3) Solder the 23ga Neotech wire (which replaces the White wire whether you are using Red or White Neotech wire) on to the lead (midway down) of the of the capacitor where it connects to the large coil.
4) Correct, or to a whisker from the cap lead after it is connected to the terminal.
-
1) Almost... "REPLACE IT WITH (YELLOW) NEOTECH 16AWG WIRE".
2) It should be soldered to the Left side of the large coil where the White and Orange wire are presently connected.
3) Solder the 23ga Neotech wire (which replaces the White wire whether you are using Red or White Neotech wire) on to the lead (midway down) of the of the capacitor where it connects to the large coil.
4) Correct, or to a whisker from the cap lead after it is connected to the terminal.
Jeff please confirm if the diagram is correct. Also, What air core do I need from you?
-
Jeff please confirm if the diagram is correct.
With respect to the diagram you sent me:
-Purple wire will not be Purple anymore. It will be Red (23g Neotech Silver/Teflon).
-The Yellow wire will not be Yellow anymore. It will be Red (18g Neotech Copper/Teflon). This wire will also connect to the capacitor lead half way between the body of the cap, and the Negative Input terminal.
-The White wire will connect to the other capacitor lead half way between the body of the cap, and the Left terminal on the large coil.
-The Orange wire will not be Orange anymore. It will be Red (18g Neotech Copper/Teflon). This wire will connect to the tinned part of the small coil lead connected to the Left side of the large coil.
-The Red and Black wire will no longer be those colors. They will both be Yellow (16g Neotech Copper/PVC).
Also, What air core do I need from you?
None. BTW, the large coil is not air core as labeled on your diagram.
-
With respect to the diagram you sent me:
-Purple wire will not be Purple anymore. It will be Red (23g Neotech Silver/Teflon).
-The Yellow wire will not be Yellow anymore. It will be Red (18g Neotech Copper/Teflon). This wire will also connect to the capacitor lead half way between the body of the cap, and the Negative Input terminal.
-The White wire will connect to the other capacitor lead half way between the body of the cap, and the Left terminal on the large coil.
-The Orange wire will not be Orange anymore. It will be Red (18g Neotech Copper/Teflon). This wire will connect to the tinned part of the small coil lead connected to the Left side of the large coil.
-The Red and Black wire will no longer be those colors. They will both be Yellow (16g Neotech Copper/PVC).
None. BTW, the large coil is not air core as labeled on your diagram.
Please confirm the corrected diagram I just emailed you. Also please let me know the value and brand of Coils which I need to purchase from you. I will be replacing all wire sleeves with pure cotton.
-
(https://www.audiocircle.com/image.php?id=185977)
-
Dan,
You do not need any coils. The diagram appears correct. And, I do not recommend cotton for these wires.
-
Dan,
You do not need any coils. The diagram appears correct. And, I do not recommend cotton for these wires.
Jeff what will happen if I use cotton sleeving? Will it introduce some kind of RFI interference?
-
The effect of cotton will not help you here, and it will allow that very pure Copper and Silver to rapidly oxidize.
-
The effect of cotton will not help you here, and it will allow that very pure Copper and Silver to rapidly oxidize.
Ok, thanks for that. I’m nearly ready to place an order. The final thing that I need from you; is for you to let me know what parts are required to modify my Beovox CX50 (INCLUDING OPTIMAL COMPONENT LAYOUT). My aim for this speaker is to achieve the following properties...
1) GREATER TRANSPARENCY.
2) BETTER IMAGING.
3) BIGGER SOUNDSTAGE.
4) HOLOGRAPHIC IMAGING.
5) NO ROUNDING OFF OF TREBLE.
6) NO INCREASE IN TREBLE SHARPNESS.
I will email you photos of the CX50 internal components.
-
I will email you photos of the CX50 internal components.
I'll keep an eye out for it :wink:
-
Dan,
Use the same wire as above (23ag and 18cu). Connect it to the same factory locations, but always make the best mechanical connection possible before soldering. I'm recommending a cap that I have not launched. It is more or less a production prototype. http://www.soniccraft.com/product_info.php/68uf200vdc-stage-p-5240 (http://www.soniccraft.com/product_info.php/68uf200vdc-stage-p-5240) It is the right cap for your sonic request.
-
Dan,
Use the same wire as above (23ag and 18cu). Connect it to the same factory locations, but always make the best mechanical connection possible before soldering. I'm recommending a cap that I have not launched. It is more or less a production prototype. http://www.soniccraft.com/product_info.php/68uf200vdc-stage-p-5240 (http://www.soniccraft.com/product_info.php/68uf200vdc-stage-p-5240) It is the right cap for your sonic request.
Ok thanks for that. However I’m going to be using somewhere between ‘seven’ to ‘nine’ Beovox CX50 speakers in my cinema system, so that means that I need to approximately ‘nine’ of those capacitors you recommended at $65 a pop. Thats on top of the ‘two’ Sonicap for the CX100 speakers. Bit too steep for me, so I think I’m going to have to plump for Sonicaps for all speakers. I was also wondering why you recommend 18AWG instead of 16AWG for the MidBass units on my CX50’s??
-
You are welcome to do as you like on all of it :wink: Making a recommendation is much easier than explaining the previous 40 years of experience that forms my opinions :green:
The lowpass in your 100s might benefit from the 16ga, but the mid in your 50s will not. BTW, the bandpass (mid) in your 100s is the same midbass that is used in your 50s. Since the wire will not help your bass, I thought I would not select something heavier that might slightly compromise your:
1) GREATER TRANSPARENCY.
2) BETTER IMAGING.
3) BIGGER SOUNDSTAGE.
4) HOLOGRAPHIC IMAGING.
-
You are welcome to do as you like on all of it :wink: Making a recommendation is much easier than explaining the previous 40 years of experience that forms my opinions :green:
The lowpass in your 100s might benefit from the 16ga, but the mid in your 50s will not. BTW, the bandpass (mid) in your 100s is the same midbass that is used in your 50s. Since the wire will not help your bass, I thought I would not select something heavier that might slightly compromise your:
1) GREATER TRANSPARENCY.
2) BETTER IMAGING.
3) BIGGER SOUNDSTAGE.
4) HOLOGRAPHIC IMAGING.
Jeff, I want to coax as much bass as I can out of the CX100’s. I think I want to use Neotech stranded for the Woofers (only). What is ideal the thickest gauge of stranded copper that I can use for this purpose?
-
12ga. The only limitation will be your ability to terminate it.
-
12ga. The only limitation will be your ability to terminate it.
I can do it. I’m resourceful. Anyway thanks again Jeff. Order placed. I will make sure to post a thread containing the finished speakers on this circle.
-
There's a pair on ebay Buy It Now for $99
-
There's a pair on ebay Buy It Now for $99
Ideal speakers for home cinema. Snap them up, they are a real bargain. For $99 you get a solid aluminium cabinet and a Bang Olufsen badge, not forgetting a great sound. However, my little CX50’s are even better for movie playback, and they are cheaper. But only after the following mods...
1) LINE ALL INTERNAL WALLS WITH ADHESIVE BACKED FELT (4.5mm thick)
2) PLAIT THE INTERNAL WIRES.
3) SNIP OFF THE PLASTIC PROTECTIVE TWEETER SHIELD WITH A PAIR OF PLYERS.
-
Snap them up, they are a real bargain. For $99 you get a solid aluminium cabinet and a Bang Olufsen badge, not forgetting a great sound.
No thanks. If I wanted another pair of bookshelf speakers I'd build one of Danny Richie's kits. But your project is interesting to follow. Trying to make a pair of 4" woofers produce some bass and keep an aluminum box from ringing is a worthy challenge.
-
No thanks. If I wanted another pair of bookshelf speakers I'd build one of Danny Richie's kits. But your project is interesting to follow. Trying to make a pair of 4" woofers produce some bass and keep an aluminum box from ringing is a worthy challenge.
I’m using them as satellite speakers in a 7.1 DOLBY SURROUND cinema system with a BK Subwoofer; so they don’t need to play bass. I’ve fixed the ringing by overdamping the cabinets with thick felt stuck on all interior walls. Lovely open sound. The bright treble that they produce is essential for matching to a cinema receiver; like my Sony STRDN1040. Movies tend to be slightly rolled off in the treble region; so the treble lift of the CX50’s comes in handy.
-
SCLARK
Check these vids out to get a rough idea of what the Beovox CX100 And the Beovox CX50 sounds like. When I listen to these clips through my Standard Iphone Earpods; it sounds virtually identical to the actual sound that these speakers produce in real life...
CX100
https://m.youtube.com/watch?v=DLWBCuBYwSg
CX50
https://m.youtube.com/watch?v=gEbbIDGPzJ0
-
Hey there - for those involved, I'd love to hear how this project turned out since I also have a set of CX100s which are in need of lots of work. Great cosmetics, but requires a replacement tweeter and refoaming the 4 woofer/mids. So, may as well go all in and upgrade the whole lot, no? Any input would be greatly appreciated!
-
Hey there - for those involved, I'd love to hear how this project turned out since I also have a set of CX100s which are in need of lots of work. Great cosmetics, but requires a replacement tweeter and refoaming the 4 woofer/mids. So, may as well go all in and upgrade the whole lot, no? Any input would be greatly appreciated!
Andy,
Unfortunately I never got around to modding the CX-100’s. For music playback I was impressed with the CX50’s after heavily modifying them. Here is a link showing the work...
https://www.audiocircle.com/index.php?topic=161358.0
-
Andy just in case you wanted advice on how to improve your CX-100’s. The image below shows Sonic Craft’s recommended modifications for that model...
(https://www.audiocircle.com/image.php?id=206945)
-
Any updates here on CX100 modifications/upgrades?
I have a set that I want to rebuild and mod for possible near-field listening on another PC rig.
I've modded many vintage Polks and want to do the same for these.
-
(https://www.audiocircle.com/image.php?id=255005)
Updates coming soon. So far; I have covered the cabinets of my CX100’s with a simulated wood finish shown here (painted and wood stained). I have also changed the capacitor to an Audio Note Kaisei. Added bass reflex port and aluminium rear panel…
-
Those look great. Looking forward to your bass port review.
I am considering power-porting these with a set of Polk power ports and will also remedy the tweeter diffuser as you have shown.
-
Those look great. Looking forward to your bass port review.
I am considering power-porting these with a set of Polk power ports and will also remedy the tweeter diffuser as you have shown.
Thanks. As an experiment, I have disconnected the ‘bottom woofer’ and am not going to rely on it to supply the bass. Instead I am performing some simple surgery on the ‘upper mid/bass unit’ with a Dremel, by cutting the metal basket frame holes larger to hopefully let more air out. The bass port will be positioned directly behind the Mid/Bass unit.
When I compared a CX50 to the CX100 I immediately noticed that the soundstage is always better and more 3D with the CX50.
-
Ok. I see, you are attempting same clarity, imaging as the CX50's you modded?
I plan on phase-plugging the upper midrange driver in mine and butyl-matting their baskets along with woofer basket.
I'll keep that in mind and maybe open the frame holes on the woofers.
-
Ok. I see, you are attempting same clarity, imaging as the CX50's you modded?
I plan on phase-plugging the upper midrange driver in mine and butyl-matting their baskets along with woofer basket.
I'll keep that in mind and maybe open the frame holes on the woofers.
Correct. By the way; here is my speaker binding post method for the ultimate performance. It allows you to clamp your favourite speaker cable directly to the circuit board of the CX100.
(https://www.audiocircle.com/image.php?id=255024)
(https://www.audiocircle.com/image.php?id=255007)
(https://www.audiocircle.com/image.php?id=255010)
-
Nice. Going to machine some TeCu posts this weekend to finish the Polk project and make some for the CX's also.
So was your port length and ID only calculated for the mid-bass?
Once you disconnect the woofers they effectively become a PR, no?
-
Nice. Going to machine some TeCu posts this weekend to finish the Polk project and make some for the CX's also.
So was your port length and ID only calculated for the mid-bass?
Once you disconnect the woofers they effectively become a PR, no?
Hopefully I can rely on bass from the modified Mid/Woofer unit combined with the reflex port tube
(https://www.audiocircle.com/image.php?id=255011)
(https://www.audiocircle.com/image.php?id=255023)
-
Simple is best. Is that a Nichicon Gold electrolytic?
I've got a couple 6.8 uf Clarity Caps coming for these and will start with adding a 1 ohm non-inductive wire-wound resistor in the tweeter circuits.
Do you feel there may be a sealing issue between the factory plastic tweeter bezel and the thin baffle housing that it is clipped to?
-
Simple is best. Is that a Nichicon Gold electrolytic?
I've got a couple 6.8 uf Clarity Caps coming for these and will start with adding a 1 ohm non-inductive wire-wound resistor in the tweeter circuits.
Do you feel there may be a sealing issue between the factory plastic tweeter bezel and the thin baffle housing that it is clipped to?
The electrolytic capacitor that I’m using is a ‘state of the art’ Audio Note Kaisei ‘bipolar’. Normally I would use a film cap for a speaker, but thought it would be interesting to experiment with a different approach, to see what the end result would be. After all, Audio Note have assured me that their cap would work safely in my project.
I don’t see a sealing issue problem with the tweeter.
-
Thank you for sharing your port idea/pics.
I have another set of these platforms that I'll experiment with. Judging by your pic. I shouldn't need more than
an inch long tube within the box to achieve port volume....
Sorry, tried inserting image here. Forum neophyte blues...
https://forum.polkaudio.com/discussion/196925/tsi-driver-dissection-and-phase-plug/p1
-
Thank you for sharing your port idea/pics.
I have another set of these platforms that I'll experiment with. Judging by your pic. I shouldn't need more than
an inch long tube within the box to achieve port volume....
Sorry, tried inserting image here. Forum neophyte blues...
https://forum.polkaudio.com/discussion/196925/tsi-driver-dissection-and-phase-plug/p1
Interesting project you got there. Here are photos showing my method for attaching an aluminium rear panel…
(https://www.audiocircle.com/image.php?id=255038)
(https://www.audiocircle.com/image.php?id=255039)
(https://www.audiocircle.com/image.php?id=255040)
-
I've wrapped up the Polk near field project. Looking forward to
modifying these so I can have the tweeter up near ear level while listening on the PC.
Did you glue those rods in, or also bolt to the front as stanchions?
I ordered thick billet plate to machine a slip-fit, but want to experiment with factory rear panel first.
-
I've wrapped up the Polk near field project. Looking forward to
modifying these so I can have the tweeter up near ear level while listening on the PC.
Did you glue those rods in, or also bolt to the front as stanchions?
I ordered thick billet plate to machine a slip-fit, but want to experiment with factory rear panel first.
The rods are ‘threaded brass’ circuit board spacers (two screwed together). They were attached to the speaker cabinet with double sided automotive tape. Then I smothered a layer of ‘outdoor wall filler’ over the sides of those brass circuit board spacers to permanently hold them in place. They are not bolted to the front baffle as stanchions.
-
Ok. Thanks for the explanation. I started dissecting the midranges today for new butyl surrounds. Went ahead and removed dust cap to confirm pole-piece is 0.997" OD
-
Well, think I figured out how to upload image from PC. Mobile not the case.
I'll try and start my own build thread here. Don't want to step on any toes.
These are on the way and started looking at cabinet modifications too.
Aesthetically, I want these Beovox to mirror my custom Polk MTM's...
(https://www.audiocircle.com/image.php?id=255106)
(https://www.audiocircle.com/image.php?id=255108)
-
The fun has begun...
https://forum.polkaudio.com/discussion/198947/b-o-cx100-crossover-enigma#latest
-
The fun has begun...
https://forum.polkaudio.com/discussion/198947/b-o-cx100-crossover-enigma#latest
Interesting. Make sure you film the finished CX100’s playing some music. Then post the video on YouTube.
-
Posited the question... For the tweeter, wouldn't this have made more sense?
(https://www.audiocircle.com/image.php?id=255172)
-
Posited the question... For the tweeter, wouldn't this have made more sense?
(https://www.audiocircle.com/image.php?id=255172)
I don’t know. Jeff recommended for me to keep the original circuit layout, but with the slight modification. What will this do to the sound?
-
I'll do that test very last since I have the x-overs externally mounted.
Still waiting on new surrounds. I did the full gamet of basket mods including open-cell inner frame foam mod and bilayer frame dampening with high density polyurethane..
I lightly doped the cones with a latex polymer, but didn't dope the woofer dust caps...
(https://www.audiocircle.com/image.php?id=255255)
-
(https://www.audiocircle.com/image.php?id=255257)
-
Replaced rotted diffraction foam with 3/8" thick wool...
(https://www.audiocircle.com/image.php?id=255273)
Billet alloy bezels will be adapted...
(https://www.audiocircle.com/image.php?id=255274)
-
Dark Charcoal Hammer patina should match the drivers nicely. Seems the factory enclosures were sprayed with a dark olive drab looking color. Drivers are finished with new butyl surrounds.
(https://www.audiocircle.com/image.php?id=255471)
(https://www.audiocircle.com/image.php?id=255472)
-
All machine work done for these. Time to assemble.
Tried starting a thread but the forum blocks me.
(https://www.audiocircle.com/image.php?id=255571)
-
I have not seen a notification of any kind if you attempted it here. However, you probably need to review the rules...
-
(https://www.audiocircle.com/image.php?id=255582)
-
(https://www.audiocircle.com/image.php?id=255582)
Nice looking speaker. Could probably get away without using using the covers
-
Thank you. I won't be covering up the artwork. After removing 1/3 the batting, doing tone sweep they drop down to 38 Hz, then it sloughs right off. Couldn't be happier. The soundstage, dynamics and even bass impact is uncanny for their size. Still burning in caps and will get a desktop vid up soon. Thanks for all the input on these...
(https://www.audiocircle.com/image.php?id=255637)
-
https://youtu.be/ZilZhMtHfYE
-
Tired of the foam I had under them to angle up at the desk....
(https://us.v-cdn.net/5021930/uploads/editor/40/aibh8pm562tn.png)
(https://us.v-cdn.net/5021930/uploads/editor/3n/sk1fkwt9r0fx.jpg)
(https://us.v-cdn.net/5021930/uploads/editor/ci/1btnkyh7o2no.jpg)
(https://us.v-cdn.net/5021930/uploads/editor/fc/8vawzvdi1euv.jpg)
(https://us.v-cdn.net/5021930/uploads/editor/ix/t0mzm6dx7wwa.jpg)
(https://us.v-cdn.net/5021930/uploads/editor/je/j8deuttlzpdl.jpg)