SURFING MUSIC SOUND-WAVES

There has been a lot of talk and debate on how to match speakers to tube amplifiers. Whilst many are mentioning high efficiency ones, the truth can be rather surprising.

Read this article, it may help you make a better choice..< The story of Tube Friendly Speakers.pdf >

I am very much a ROGERS and PROAC fan , so you will not see many speaker brands here.

the  ROGERS  LS 3/ 5A Bookshelves                         PROAC R1S  Bookshelves   The PROAC R3 floorstands   matching my monoblocks SE40 amp      07 February 2009:  For some time did I complain about the "harsh" image of the tweeters, I done changes but it all did not work . Finally Troels Gravensen from Denmark came to my resque and did some analysis . Before :                    Graph  vs. the related Cross-over PCB  After Troels recalculation  :     Troels new calculation dealt with the previous dip at the mid frequency and sudden rise of the treble . The rebuilded cross-overs made the curve more lineair in overall . The overall sonic became amazingly much better . The simpler layout of the cross-overs also provides a more direct path for the signal ; the result is a more cleaner , detailed and finer sonic. So.. its KIS ( keep it simple ) again. Thank you Troels ....!!!!! for those interested who Troels is....visit his web :  http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm You will be amazed what he had achieved !!!     Note: Have  you every thought that placement of the inductors on your crossover board does  impact your speaker sonic ????? Read Troels article on this :... <<<< click here for more >>>>        Coral Flat 6  full-range driver speakers  a long (2 years) delayed project finally finished 02 April 2008  SOLD  Thank You to YUSTINUS LIMARGA - Audiokitchen , Bandung ,  for making the big cabinets .

View of the LS35A Drivers             I like these R1S  speakers. They are very dynamic and match with my SE 2A3 amplifier               Close-up of the drivers      Tweeter : SEAS type 9500 Woofer: SEAS 8543

2 September 2008.

This R1S clone-kit  is made in China, available through "WAI WAI Valves" - Hongkong. Perfectly made and beautifully finished cabinets ! But NOTE :  its not made of real wood , only synthetic material resembling it.

                     Front view                                                        Back view

 Drivers are the same Danish products (...how can I distinguish whether these are Scanspeak/ SEAS  "in China" ? ...they look all the same....) as used as in the original R1S: 

      SEAS T14 RCY/P-H woofers                  ScanSpeak D2010/851300 tweeters

 The Proac R1S crossovers are of a traditional  approach - a combination of 2nd order at the mid/woofer and 3rd order for the tweeters.

The topology is in a ready made crossover PCB made in China . However parts  are "budget class" .

Serious upgrade homework  if I want the typical Proac "luxury" sound.

11 September 2008

All mylar caps were removed and replaced with MKP caps , then bypassed with PIO
 

 A short trial run on the new caps did gave   a significantly   more smooth and natural sound quality. There is but still much  audible differences vs.  the original R1S. The clone's voice   lacks the original speakers tonality, low bass and slamm,  imbalance between treble and mid/bass sensitivity , needs much more smoothening .

So next steps planned are:

Changing the china-man  inductors with better quality ones , adjust  the inductors values  , installing a level pad to equalize the tweeter and woofer sensitivity , change the harsh wires with better quality ones..

 20 September 2008:

 Level padding (LPad) is based upon differences of:

Tweeter sensitivity 90Db  vs. Woofer sensitivity 86Db  and  contributory factors of other crossover parts 4Db, needs further damping of around 8 - 9Db. By using two resistors of 5R6 each, a additional damping of 8.6 Db is achieved.

Tweeter is now less  aggressive and imrpoved  to the mid/bass level 

 The mid/bass notch filter :

The 47uF/100V  "economy" chinese CYC blue non-polar cap is replaced with a 33uF/100V square red-color MKS WIMA

The change contribute to more focussed mid and bass
Tonality improved ,

This could  lead to changing the existing inductors . Challenge is the funds needed and limited space available to mount 

 28 September 2008

1) Replaced 5 uF in the high Pass Filter to 6.8uF.  Result = better bass authority and slam presence 

2) Replaced the fluffy backplate dacron "fishtank filter" stuffing with 1.5cm thick foam all over the inside box . Result = better focus   and  vocal body

Next step :

Better quality inductors

 .........I keep you further advised  .................

20 March 2009...

...  Still unsuccesful !!!  The sound is still  "terrible"

10 July  2009

.....  Tried building new cross overs as exact as possible (values and material) . Though the drivers were original SEAS and SCANSPEAKS , the sound signature ARE NOWHERE in matching  the original R1S.

It appears then that the material used to build the cabinets and stuffing causes the big difference.

I GIVE UP.....CASE CLOSED  ???

 .............<<    another Cinderella ? ????..........sight sight....... >>

NOT REALLY THOU..... being a DIY'er ....that would be a disgrace to the money  spend  !

20 November 2009

My dear friend Malion dropped me a tip , so excellent but simple  which turned all the cards in my favor.

I am happy < grin grin..>  and at this moment I now need to tweak further to get the harmonics / timbres as to my liking..

I keep you advised. Some better quality parts needs to  be used on a  step by step base  in the  continued effort

25 November 2009

The Clone is now being broken in, attached to a radio tuner. Lets see the results after one week  continuously being used.

I am thinking of new inductors , I have asked Setiawan help to wind me some new inductors.

16 December 2009

Break-in results is much encouraging !

I am interested to find out whether this clone  would sound at least near to or gained some of the specific Proac R1S sound signature  - lets compare after the burn-in period.......

. PJ

 
Cabinet  (real wood) , drivers  and sound  is excellent . Contrary to the clone , it  has the distinct Proac R1S  tonality.

My plan is to pair it with my  EL34 Audion Sterling ,....  a present  for  my youngest girl who also loves music.

Only the tweeter faceplate foam starts to rot and needs replacement -   I am trying to source one , bad thing is that Scan-Speak  Denmark now does not sell the foam pads any longer , it must be bought with the tweeters as one whole set....   <<wowwwww....wowww...>>

01  Oct 2009 .

Changed the Scanspeak tweeters ....(you still can get them at www.Madisound.com )

All is OK.... thou still standard (untweaked), these lived up to the Proac reputation !

  EXCELLENT SPEAKERS !!

20 November 2009

The 2nd R1S is now fully tweaked , using Loc Vu (USA) gift : MICAMOLD and AEROVOX capacitors .... and you know what ..... IT OUTPERFORM  my first pair !!!

It seems to become a never ending story.... I have to adjust my first pair now with those  caps ....

 24 November 2009

The second R1S is now being broken in. Sonic-wise  it became  superior than the first R1S. As Loc Vu said, the Micamold and Aerovox  caps are much classier than the MBM's

I tried to replace the first R1S with them , but unfortunately the speakers became rather too aggresive to my ears . So , for the first R1S , it is  back using the old capacitors .

Funny that with all the parts standardization , standard sonic quality can never be achieved !