High Efficiency Speaker Asylum

MCM 55-1220 12" poly cone woofer

96.11.127.78

deathtube 667

A

Anyone here try this woofer?

I have a 3.75 cu. ft. box and played around with some WinISD plots for a vented enclosure.

Not really sure what the best or optimal porting should be.

I can measure with ARTA LIMP to get alternate TS parameters if needed.

Trying to construct a mono speaker for testing low powered SE tube amps.

I'll use some 1K cycle horns and perhaps a tweeter for the top end.

Any suggesting on box tuning?

http://www.mcmelectronics.com/product/MCM-AUDIO-SELECT-55-12 (Open in New Window)

Follow Ups:

RE: MCM 55-1220 12" poly cone woofer - djk 22:59:18 07/01/14 (3)
Measure the actual parameters, I doubt they are even close.
- RE: we shall see... - deathtube 667 03:58:46 07/02/14 (2)
  Here is the TS data gathered from ARTA LIMP using the added mass method.
  I used a 28 gram added mass.
  The data file on the 55-1220 suggests that they used 30 grams for their measurements, so used an added mass close to that.
  Parameter, Value, Dim
  Fs, 26.34, Hz
  Re, 5.30, ohms[dc]
  Qt, 0.28, -
  Qes, 0.35, -
  Qms, 1.38, -
  Mms, 52.95, grams
  Rms, 6.819896, kg/s
  Cms, 0.000671, m/N
  Vas, 423.34, liters
  Sd, 670.12, cm^2
  Bl, 11.995520, Tm
  ETA, 2.37, %
  Lp(2.83V/1m), 97.63, dB
  , ,
  Le, 231.09, uH
  L2, 1456.72, uH
  R2, 19.62, ohms
  L3, 0, uH
  R3, 0, ohms
  I'll put the data in WinISD and see what happens to the results.
  
  Edits: 07/02/14
  - RE: we shall see... - hennfarm 21:10:08 07/02/14 (1)
    Wow, that is light for a poly cone. Impressive how close to mcms specs.
    - RE: we shall see... - deathtube 667 22:46:40 07/02/14 (0)
      I ran the TS parameters in LIMP again with a 90 gram added mass.
      That was right in the middle range of what the program said was the ideal phase shift between the added mass and non added mass measurements.
      WinISD said a 3.75 cu. ft. closed box would be an ideal enclosure.
      Since that was the size of the box I had, I installed the 55-1220 and let it run full range in the closed box.
      I threw a Magnavox horn on top of the box crossed over at 2K cycles first order with L-PAD.
      The WinISD plot had the low end rolling off at 100Hz, so there was no deep bass when I listened to it.
      Edit: got up this morning and ported the box. It is tuned to 38Hz.
      Took a Hz sweep in room.
      The horns have a bump in their response.
      I might try to work on a notch filter, but it is not critical.
      The low end down from 1KHz was better with the 55-1220 compared to the Olsen 12" woofer I had in the box previously.
      
      Edits: 07/03/14
RE: MCM 55-1220 12" poly cone woofer - hennfarm 19:45:19 07/01/14 (1)
http://www.loudspeakersplus.com/choosing_the_correct_speaker.html
- RE: MCM 55-1220 12" poly cone woofer - deathtube 667 20:52:07 07/01/14 (0)
  I'll tune the box somewhere between 38-42Hz and hear what sounds best.
  
  I looked at a lot of low cost 12" woofers and the 55-1220 seemed like the best fit for that box.

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