Tony_J

Moderator
  • Content Count

    8,715
  • Joined

  • Last visited

  • Days Won

    12

Everything posted by Tony_J

  1. Tony_J

    one word daily

    Ruth
  2. Tony_J

    one word daily

    Tag
  3. Tony_J

    A frank seller!

    That's an expensive pack of 3
  4. Tony_J

    Ed Selly reviews the Kii THREE

    You've obviously not heard about the new "Power over WiFi" standard...
  5. Tony_J

    one word daily

    Billy
  6. Tony_J

    one word daily

    bitter
  7. Tony_J

    Measuring T/S parameters using REW

    Had to redo my measurements because I was using new-style pound coins as known weights & the website I got the weights from was wrong...so the added weight figure I was using wasn't correct So, the detailed values generated by the DATS system have changed slightly, but still looks to be producing more believable numbers than I was getting with the REW setup.
  8. Tony_J

    Measuring T/S parameters using REW

    I've been attempting to use REW to measure Thiele-Small parameters of a driver, with no success so far - entirely failing to get the impedance measurement feature to work, which is a necessary pre-cursor. I'm using the setup described here: https://www.avsforum.com/forum/155-diy-speakers-subs/1340740-lilmikea-s-diy-impedance-measurement-jig.html with a slight variation - I had a two-gang switch so used one gang to short out the sensing resistor and the other to disconnect the speaker leads for calibration. So should work exactly as described in the article and in the REW help, but it doesn't - the calibration scan gives a suspiciously good 100% reading, and the impedance scan suggests an impedance in the meg-Ohms range, which is clearly wrong. I am using the current version of REW - V5.20 Beta 8 - so the software should be current. I have tried it using the Behringer interface suggested in the article, and also using a different USB sound interface - same results. Anyone out there that has attempted to do this, and succeeded?
  9. Tony_J

    one word daily

    Farage
  10. Tony_J

    Digital Source Question.

    As long as they are lossless, no.
  11. Tony_J

    one word daily

    Spigot
  12. Tony_J

    Measuring T/S parameters using REW

    My impression from the sound level produced during the sweeps is that both systems are using a similar signal level. Certainly, the TS parameters are "small signal" parameters - i.e., intended to be measured within the linear operating region of the drivers. I will let you know how I get on. The intent is to use the DC drivers (which I used in one of my Kegworth systems) along with either 2 or all 4 of the bass drivers in a 3-way - the DC doing mid bass/mid and treble. Not yet sure whether to go for a conventional ported or sealed box for the bass, or whether to go a bit off piste with a band-pass design, or even an isobaric... A bit of modelling is going to be needed! One thing that seems clear having measured the tweeters is that my Kegworth system was using a crossover frequency that was pretty much the same as the tweeter's resonant frequency, which wasn't too clever - received wisdom seems to be that it should be at least 2* f(s). So that needs some playing with too.
  13. Tony_J

    Measuring T/S parameters using REW

    I'd agree with your assessment Robert - the REW data doesn't look good to me either. I haven't looked up the bass units online yet, but I couldn't find any published data for the DC units last time I looked. An interesting difference between the two systems was that when doing the second pass to determine Vas, DATS seemed to require sufficient added mass to shift f(s) by at least 25%, so where I was using 3.5g (a 1p piece) added to the cone in REW, the DATS needed 19g (two pound coins) added before it was happy. That may account for some, but not all, of the differences in measurements. Anyhoo...time to use the data and design some cabs!
  14. Tony_J

    Measuring T/S parameters using REW

    OK...the DATS gizmo arrived in the post today, and I have been repeating the set of measurements that I took using the REW rig. First impressions - the DATS software/hardware is REALLY easy to use - took me about half an hour to measure 8 drivers, including the time taken to remove 4 of them (2 DC units) from their cabinets. The displays are good too. I've done a quick-and-dirty spreadsheet to show the comparison. The first four drivers are Tannoy 8" bass units - two pairs, each pair coming from a different Tannoy speaker, but all 4 nominally the same Tannoy driver model number. The 5th and 6th are the bass and treble sections, respectively of a Tannoy 8" DC drive unit, ditto the 7th and 8th. I had not recorded anything other than f(s) for the treble units on REW, and of course Vas isn't measured for them. Tannoy 8 inch - comparison DATS vs REW.pdf Looking at the data, I get the impression that the DATS measurements are more consistent than the REW ones. Whether that is a fair reflection on the accuracy of the two systems or not, the ease of use of the DATS system makes it a clear winner as far as I am concerned!
  15. Tony_J

    My son releases his first single

    Interesting sound!
  16. Tony_J

    Speakers for garage and for bedroom

    I know the Scots have a thing about deep frying anything that moves, but battered speakers...?
  17. Tony_J

    Three Words Daily

    Because rusty shears...
  18. Tony_J

    naim 555 ps s//h

    Expensive though - cost 2 arms and 4 legs
  19. Tony_J

    naim 555 ps s//h

    It's all about the name...
  20. Ah, but that's only the K-II model...the K- IX is definitely the dog's doodahs ...
  21. Depends whether they are wearing their tinfoil hats or not...
  22. Tony_J

    Speaker design software

    I've dabbled a bit with one or two of the free speaker design apps, but haven't really got to grips with any one of them so far and have no clue as to whether they are any good at what they do. What design software have you tried an which do you find actually work well?
  23. Tony_J

    Three Words Daily

    Reached elastic limit