The 2.5 clone papers - CCRMA

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Comments to tweeter modifications 1. First of all your tweeter mod is excellent, the sibilance has really gone and the sound is much smoother than before. Zoltan. 2. This is quite a delicate operation! The only thing I found that was not in your instructions was that after the rubber gasket is removed, it is necessary to tap the plastic casing on the side to allow the driver parts to fall free (at least it was in my case). It confused me for a few minutes until I figured it out. Aside from that, everything went well. I did both drivers at the same time and was keen to hear the result, so I've temporarily attached the back plate to the housing with electrical tape - don't worry, it's airtight and I'll redo it properly with silicone tomorrow. Well, all I can say is that together with the minor crossover mods and extra Damar coating on the 8535, this makes the most significant improvement since your original notch filter. Everything you say in your paper is 100 per cent correct - the tweeter coating really does transform the speaker. The last traces of the original clone's "technicolour" sound are gone, so I guess it's not going to please everybody, but sibilants now sound totally natural, even if they are still a bit more pronounced than in some other designs. The important thing is that they don't "ring" and they don't irritate. I also agree with your description of the treble as "darker", and yet - you're right - at the same time there's more presence to the sound! I think we've been unfair to this tweeter; it had far more potential than we were allowing for. There is now obviously far better integration between the two drivers. It's very strange, but I have to agree with you also that the midrange "hardness" is now much reduced - or at least much less obvious, and it's possible to hear depth layering where it didn't exist before. I have yet to listen to all my "difficult" recordings, but the few I have tried all showed a marked reduction in "listener fatigue". I can enjoy most of them again! I can't say I always find the "carbon-fibre" midrange to my taste, but I can now appreciate it for what it does. The clone truly does now fit the description of a "high-end" speaker. Very impressive. Darryl. 3. I have been briefly comparing Troel's modified 8513 tweeter (ferrofliud removed an applied damar coating to cone) and it is very nice. I must modify the woofer crossover to Troel's suggestions before I make any final conclusions but dropped it into the current crossover and it sounds more neutral, less sibilant when CD tracks have too much energy. The same 36 basic sound character is retained but enough treble zing is shaved off for those who want this, IMO. At this point in time I still prefer the standard unmodified tweeter as there is more of that original Proac lushness, sweetness and detail, but can be sibilant on some tracks, which seems to be the tradeoff. Al.M 4.a - modifiserte 8513 i går, pluss at jeg satte inn en 10ohms motstand i mitt No1. Filter. Har forresten bestilt deler til No6. filteret i dag.(gleder meg) Resultatet av tweakingen er enorm! Må bare takke! b. After many more ours of listening to the clones and the V6 filter, I have come to what will be MY final filter. Sorry, but I was a little to fast to accept the filter for the 8535. The V6 filter sort of shows the true nature of the 8535, a hard sound....... But with the V1 filter too the 8535, and the latest (in the link) to the 8513 + the modifications with the tweeter, the sound is the most acceptable ever. I can still hear the 2000Hz bump but then mostly when I listen to TV. The sound on most recordings now is warmer than with the V6 filter. But now I can for the first time totally relax when listen to my favourites. c. Dear cloners I really recommend this modification of the 8513 tweeter. I can promise a sweeter treble. And the metallic sound is totally gone! In fact the whole speaker can be as fantastic as people said, from bottom too the top. I have had big problems accepting the clone`s sound until now. This tweak together with the v6 filter and I can call this speaker superior! I agree with Troels that this is the final version! d. There is said many strong words about the sound of the clone, but I cant understand how so many people have accepted the sound of the early clones! I can imagine Mr. Steward Tyler having a good laugh more than once! But now He he he......... Regards from Tor Hauge...Norway
37 The new coated 8535 drivers from ScanSpeak b. LCR notch filter for the 750 Hz bump = 10 mH (2 x 4.7 mH, 0.65 ohm) + 10R + 6.8uF. As mentioned in my former file on tweeter coating, the new 8535 drivers have a coating on the rear of the cone. This is a deviation from former 8535 drivers and is easily detected on measuring performance. 90.0 dBSPL TGAudio MLS - Frequency Response 26-06-03 22.00.12 80.0 108.0 70.0 36.0 60.0 -36.0 50.0 -108.0 40.0 -180.0 200 1k 10k Hz 20k CH A dBSPL 1/12 Octave 51.2kHz 16K Rectangular Start 2.66ms Stop 5.86ms FreqLO 312.20Hz Fig.1. New coated 8535 and V6.1 crossover. What can be seen from this graph is a 3-4 dB bump at 600-900 Hz, and due to an earlier roll-off characteristic, a dip at 3 kHz. Here’s the response from the old drivers with modified tweeter, crossover V6.1: 100.0 dBSPL TGAudio MLS - Frequency Response 27-05-03 22.09.01 90.0 108.0 80.0 36.0 70.0 -36.0 60.0 -108.0 50.0 -180.0 200 1k 10k Hz 20k CH A dBSPL Unsmoothed 51.2kHz 16K Rectangular Start 2.93ms Stop 6.04ms FreqLO 322.01Hz File: 1st coat 72 h.mls Fig. 2. Old 8535 driver response. Blue and red are various measurements during tweeter coating. It’s my feeling, that these drivers will be best suited with tweeters like ScanSpeak 9300/9500/9700 and a target point of crossover at 2-2.5 kHz, possibly 6- 12/18 dB. Furthermore, a notch filter is needed for the 750 Hz bump. To my knowledge, this change in performance has not been announced by ScanSpeak and can only be identified by measurements or visual inspection. I have tried to tweak the V6.1 crossover to adapt to these new drivers: LP-section: a. 1.8 mH-(7.8uF+4R7)-0.47 mH CLIO CLIO 180.0 Deg 180.0 Deg HP-section : No changes. Fig.3. V6.2 90.0 dBSPL TGAudio MLS - Frequency Response 19-07-03 22.05.18 80.0 108.0 70.0 36.0 60.0 -36.0 50.0 -108.0 40.0 -180.0 200 1k 10k Hz 20k CH A dBSPL Unsmoothed 51.2kHz 16K Rectangular Start 2.46ms Stop 6.02ms FreqLO 281.32Hz File: V6.2-7.8+4R7.mls Fig.4. Frequency response of new crossover. LCR components: Fig. 5. mid-LCR. - And don’t spend a fortune on notch filters unless you think this is the speaker of your life! This shouldn’t cost you more than 20 US$ in all for two. CLIO 180.0 Deg
Page 1 and 2: The 2.5 clone papers by Troels Grav
Page 3 and 4: 3 Tweeter polarity My first comment
Page 5 and 6: 47 ohms resistor in HP section. In
Page 7 and 8: Significance of LCR on cumulative s
Page 9 and 10: Fig.16. System response with Fig. 1
Page 11 and 12: TS parameters at different measurin
Page 13 and 14: 100.0 dBSPL TGAudio MLS - Frequency
Page 15 and 16: Impedance of system with series fil
Page 17 and 18: Construction of bass reflex cabinet
Page 19 and 20: At last, the final cabinets with dr
Page 21 and 22: 100.0 dBSPL MLS - Frequency Respons
Page 23 and 24: Let’s take another look at the fr
Page 25 and 26: 2.5 clone crossover, version 6. Twe
Page 27 and 28: 110.0 dBSPL TGAudio MLS - Frequency
Page 29 and 30: Sonic evaluation of modified 2.5 cl
Page 31 and 32: 31 Modification of ScanSpeak D2010/
Page 33 and 34: Listening tests The listening sessi
Page 35: The 2.5 clone now bear little resem
Page 40 and 41: New project to come: “The Point75
Page 42 and 43: Totem Acoustic Mani2 KEF RDM Dynaud

The 2.5 clone papers - CCRMA

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