Measurements on my Subs

Discussion in 'Home Theater Projects' started by Joseph Sabato, Jan 4, 2004.

  1. Joseph Sabato

    Joseph Sabato Stunt Coordinator

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    I finished converting my second AR tower to a Mid Q Tempest Sub over the holidays and finally got around to taking some in room measurements (AT THE LISTENING POSITION) with a Radio Shack Meter (with readings corrected) of each sub individually and the total response from both.

    Overall, I am pleased with the results but may take the next step by going the IB route if I can get better measured results, which I will test by moving one of these to the outlet location.

    The results are at home.fuse.net/jgsabato
     
  2. Wayne Ernst

    Wayne Ernst Cinematographer

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    Joseph,

    Thanks for sharing your sub information. It looks like the chart with the plots on your Web site is not properly referenced on your server where the graph is stored. The image in the HTML is still bein referenced on your "C" drive instead of at the Web server - so, we can't see it.
     
  3. Joseph Sabato

    Joseph Sabato Stunt Coordinator

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    Thanks Wayne,

    let me see if I can fix it
     
  4. Joseph Sabato

    Joseph Sabato Stunt Coordinator

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    I forgot to upload the chart. I forgot that I can see it even if is not on the server, it has been a while since I updated the page.
     
  5. Wayne Ernst

    Wayne Ernst Cinematographer

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    Joe,

    I can now see the chart. Readings

    It just looks like the HTML page needs to reference the image.

    Thanks again for sharing the background on this very neat way of "recycling" some old AR cabinets for use with new Tempest drivers.

    I'm not sure if I noticed what you are powering them with. Are you driving them with a separate "pro" power amp? Thanks.
     
  6. Joseph Sabato

    Joseph Sabato Stunt Coordinator

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    Wayne,

    I am using regular audio power amps. I have a couple of old (25+ years!!) SAE power amps that are darn near bulletproof to drive them for now. If I go the IB route, the Tempests will be excursion limited so there is no need for more power than what I have.

    I have been looking at Pro amps recently to get more power if I decide to keep them in the cabinets. I am noticing some very low level hum recently, probably from the electrolytic caps drying out ( getting old, like me), so I might make the change soon anyway. I was concerned about the consumer/pro equipment matching issues, but after visiting a local music/pro equipment store with very knowledgable people, I have no concern at all...they had everything I would need to match things up....just have to figure out how to quiet down the fans.
     
  7. GrahamT

    GrahamT Supporting Actor

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    I think you should do IB. You notice how the subs are almost 20 dB down from 40Hz to 25 Hz. Also co-locating in a IB them should improve the response below 30 Hz because now they are cancelling each other.
     
  8. Joseph Sabato

    Joseph Sabato Stunt Coordinator

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    Graham,

    That is what I really want to do. The dual Tempest IB models at 10 Db greater output at 20 Hz than the single sealed mid-Q setup I have in near field measurements ( 1 meter).

    In the room, based on measurements I have taken already, If I could put the manifold outlet where the front speaker is ( I can't) it would be a killer!

    I will have to put the outlet high on the front wall, I modeled what would be the best position, I will put one of the towers on top of the wall units and take measurements before I cut a hole, knowing I will get more bass below 40 in the final setup.

    The next step is convincing my wife to let me cut the hole and have the speakers in the garage ( No, dear, I don't think the neighbors will hear it...)
     

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