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MarcAL

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About MarcAL

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    Sydney
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    Australia

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  1. MarcAL

    DIY audio: what are you building?

    Not sure what GFRC is so I googled it and up came Georges River Football Club.😏 However I am curious as to what you propose to cover the GRFC with and to perhaps give it a decent WAF? Never the less please post some pictures, time permitting, of the cabinets including the amplifier line up you plan to use to get 9 or 10 channels with. I like to see what I may be missing out on. I had tried active crossovers at first with my 2 way line up with okay results but for now the Hiraga passive crossover network works a treat. Yes, I know, the finished article again, looks the same but now it's sounding even better, it must be the Russian PIO that seems to be getting better with age perhaps. No more mess on the floor of the tribal listening room and totally out of sight behind the Onkens.😎 Note: the timber panel on the crossover board is a foot so it can stand upright with the terminals at the top for easier wiring access.
  2. MarcAL

    DIY audio: what are you building?

    You can just parallel outputs if you want.
  3. MarcAL

    DIY audio: what are you building?

    I used decent quality solid copper banana posts as seen in the pictures previously so the crossover networks are modular and field replaceable. I avoid crossover networks in cabinets when external horns are used.
  4. MarcAL

    DIY audio: what are you building?

    I use plastic self adhesive cable saddles known in the electrical industry as sticky backs. When I mount these to a board such as bakelite I also place a small countersunk brass screw through the center so they will never come loose but a countersunk screw so you can still place a cable tie through it. These are mainly used for mounting capacitors and inductors or anything that can be held down with a cable tie. Inductors are usually held down with cable ties with a strip of close celled self adhesive tape underneath as used for draft exclusion around windows and doors. Resistors of small size are are usually soldered to tag strip however larger ones with a decent hole through the centre are better held down with a brass or stainless steel screw or bolt. I am not shy of using decent quality hookup wire as component placement is far more critical than point to point wiring as inductors do require sufficient separation from each other and from ferrous metal including screws. Hope that this is of interest. Feel free to ask any questions.
  5. Item: Altec Lansing MR II 564 Large Format Mantaray Horns Location: Sydney South Price: $220 the pair or $125 each Item Condition: Used, good original condition, see pictures Reason for selling: NLR Payment Method: Pickup - Cash, Paypal, COD Only Extra Info: Altec Lansing MR II 564 Mantaray Constant Directivity Horns for large format 1.4" compression drivers. PM me if you require large compression Altec drivers to suit. Nominal Dispersion Angle: 60 x 40 degrees. Useable Low Frequency Limit: 500Hz. Construction: Heavy duty, weather resistant polyester/fiberglass. Finish: Standard Altec grey with a few minor scratches, can be resprayed another colour for an additional cost. Suitable Drivers: Many 1.4" throat compression drivers or Altec Lansing Large Format Compression Driver models 288, 290, 291, 299 etc. Small format compression drivers can also be used with the use of an adapter. Data Sheet: http://pdf.textfiles.com/manuals/STARINMANUALS/Bosch - EV/Archive/Altec/MRII 564.pdf Weight: 2.1kg each. Shipment: Will send interstate at purchasers expense, free delivery within Sydney. Pictures:
  6. MarcAL

    DIY audio: what are you building?

    Glad to see the Altec horns getting a work out. I bet you can hear the dialogue from the screen more clearly now. Excellent stuff!
  7. MarcAL

    DIY audio: what are you building?

    Today I spoke in front of the horns and noticed that I could not only hear my voice bouncing off the inside of the horn but also a slight reverberation artifact from the horn itself. So I decided to give one of the horns the sound deadening treatment and then compare again as above and with the knuckle tap test. There was a significant improvement and a lot less noticeable reverberation from the large horn panels. So with that being a success as with other horns treated in the past I treated the remaining horn. So now both are done and sounding much better however the stench of the glue is overbearing!🤢 This time I didn't want any product logo visible as with the self adhesive types so I chose to use one without branding and hence I had to use an additional adhesive. Tomorrow I will have a listen as tonight the smell is too strong but already even without music they sound much better. Or maybe it is the side effects from the glue.😵 I think next time I will leave them in the garage to dry overnight.
  8. MarcAL

    DIY audio: what are you building?

    I found that when you do veneering that you must sand and stain or oil the veneer the same day. I did not do this on my first build and it started to bubble and lift off over night. This was due to the humidity up here in Sydney and is quite high over summer. To fix this the next day I then placed a sheet of A4 paper over those areas and applied heat from an iron. It remelted the adhesive underneath and all was fixed but will only work if you have put sufficient glue on to start with. That was more than 15 years ago and is still 100% now. Over time the veneer received a few bumps and gouges so I placed a scrap over it and cut it with a scalpel. I then removed the old piece underneath, cleaned it up then glued the new piece in place. Then sanded the whole side back lightly, stained and now it is undetectable. The good thing with veneer you can refurbish it in the future and it can look brand new providing you keep your scraps. So don't throw them out and keep them in a safe dry place as new veneer can be different. Below is the first build on the left and second build on the right. Note the different shades of veneer over 6 years.
  9. Thanks for that but I still don't get how this happens as I had changed this listing a fair bit from the original one posted last December. So it should have appeared as a new listing with just the title as being 'Relisted'.
  10. MarcAL

    DIY audio: what are you building?

    I was only joking about the crossover networks. Ha, Ha, they can take days with design, sourcing parts, testing, building and a life time of listening hoping that they don't require any revisions in the future. But on a serious note are you going active or passive and what are your crossover points? The veneer however is what I was really admiring. Real quality job. I have taken on this task previously on other builds and I know how difficult and time consuming it can be. It looks like you have mastered it, you definitely have patients, brilliant!!
  11. MarcAL

    DIY audio: what are you building?

    These are magnificent! Excellent recessing job of the baffles for the drivers and speaker fixings look pro. I am wondering how you skinned the cabinets so neatly. Can't wait to see the bass cabinets completed. By the way do you require crossover networks? Keep up the good work.
  12. MarcAL

    DIY audio: what are you building?

    I have wound chokes by hand in the past however that is too expensive due to the amount of labour involved. The ones used here are air core Solen for the high pass filter and iron core ERSE for the low pass filter all 6.8mH trimmed down to 6.6mH. All of the inductors were measured with an inductance meter in free air away from any ferrous materials such as metal work benches etc. That is why the two iron cored inductors are placed well apart on the board.
  13. MarcAL

    DIY audio: what are you building?

    At last the crossover networks are completed! Features: Bi-amplified or bi-wireable input connections 12dB high pass filters with high frequency boost for 24 ohm drivers 12dB low pass filters configurable for 8 or 16 ohm drivers Zobel networks configurable for 8 or 16 ohm drivers Constructed on recycled 640 x 320mm Bakelite panels, 8mm thick Jumper configurations: Jumpers in: 2 x 6.6mH inductors in parallel to get 3.3mH with 0.14 ohm DC resistance for 8 ohm drivers and Zobel network to suit Jumpers out: 1 x 6.6mH inductor to get 6.6mH with 0.28 ohm DC resistance for 16 ohm drivers and Zobel network to suit Flexible for now and no need for major modifications in the future... well that is the plan. The main priority now is to sit back and listen.
  14. MarcAL

    What to do with old CDs?

    If one was to purchase this chair would only one person be allowed to sit on it? Heaven forbid if you ripped the fabric!
  15. Item: Altec Lansing MR II 564 Large Format Mantaray Horns Location: Sydney South Price: $225 for the pair Item Condition: Used, good original condition, see pictures Reason for selling: NLR Payment Method: Pickup - Cash, Paypal Only Extra Info: Altec Lansing MR II 564 Mantaray Constant Directivity Horns for large format 1.4" compression drivers. Nominal Dispersion Angle: 60 x 40 degrees. Useable Low Frequency Limit: 500Hz. Construction: Heavy duty, weather resistant polyester/fiberglass. Finish: Standard Altec grey with a few minor scratches, can be resprayed another colour for an additional cost. Suitable Drivers: Many 1.4" throat compression drivers or Altec Lansing Large Format Compression Driver models 288, 290, 291, 299 etc. Data Sheet: http://pdf.textfiles.com/manuals/STARINMANUALS/Bosch - EV/Archive/Altec/MRII 564.pdf Weight: 2.1kg each. Shipment: Will send interstate at purchasers expense, free delivery within Sydney. Pictures:
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