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ligs

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  1. ligs

    AR speaker low frequency perspective

    I found an on-line version of an article by D.B.Keele, jr, who specialized in testing and reviewing (sub)woofers. http://www.gammaelectronics.xyz/audio_11-1992_sub.html I thought it would be interesting to include some of his findings in the discussion of bass reproduction. Figure 1 is the frequency response of 4 subwoofers. Figure 2 is maximum peak sound output vs frequency including the effects of room gain. Therefore the typical manufacturers’ spec on frequency response (measured at 1 w or 2.83 volts) does not predict completely how the speaker will perform at realistic sound level in your room.
  2. My guess is around year 2000. They look like this. Yes it has a 6.5 " heavy duty cast frame woofer but is sealed. http://xcsdfarew.blogspot.com/2013/03/jbl-studio-s36aw-ii-3-way-high.html I am surprised it has a very complex crossover.(mixed 2nd and 3rd order slopes). I was playing them as full range in parallel with NHT 1259's. The rest of Studio series are vented. Stereophile has a review of its 8" big brother S-38. https://www.stereophile.com/standloudspeakers/365/index.html George
  3. Experimenting further with a LCR trap in woofer’s crossover removed a slight hump around 1000 hz. This improved the vocal quality of JBL127H-1/RST 28 A-4/NHT 1259. Here is a comparison of my DIY satellite vs commercial JBL Studio 36ii (6" three -way)and Infinity Reference R162(6" 2-way) speakers. Above 2000 hz all three have very similar response curves. Please disregard 200 hz and below because of the room effect. I can live happily with any of the three choices. On louder passages, the JBL127 H1 sounds more relaxed, perhaps its low distortion is a contributing factor. George
  4. I have a very rough idea about the frequency responses measured in my room with the help of a Radioshack analog SPL meter and Stereophile test CD. The response cures will not be comparable to any other lab measurements. These curves are not calibrated and are meant to serve as a comparison purpose. The microphone is placed about 1 meter between the JBL woofer and tweeter. Keeping that in mind. It does appear that JBL 127H1 satellite without NTH 1259 begins to roll off below 200 hz. This is due to the very small sealed box volume , a 50 ohm resistor across woofer and the placement of the satellite without room boundary reinforcement. Combining with NHT 1259, the entire bass region (red and green lines) becomes flatter and extends at least to 32 Hz. As shown. George
  5. Yes, 32 Hz refers to the combined (connected in parallel) response NHT 1259 and satellite with JBL 127H1. NHT 1259 has an in-line low pass passive crossover at around 100 Hz as in NHT 3.3. The satellite is about 2 ft away from the backwall and just sit on the boxes containing the sealed NHT 1259's. Madisound used to sell a version similar to NHT 1259 but is no longer available. http://www.madisound.com/pdf/MAD1259.pdf George
  6. In my main listening room I am using Dayton SA1000 with a pair of HSU TN1220's subwoofers which have received a rave review in High Fidelity magazine. http://www.gammaelectronics.xyz/audio_1998_Aug--hsu.html Also I am using my pair of NTH 1259's as the woofers of my 92 db satellite speakers(JBL 127 H1 and Dayton RST 28 A-4). They are flat to 32 Hz and then dropping off rapidly in the room. Therefore I need to use HSU TN 1220 for the last octave. In my family room with Samsung smart TV, I am using a pair of Infinity Reference R162's and a pair of HSU HRS10's driven with a Dayton SA500 Let me try to upload the third page of the article mentioned before. George
  7. Here is page 3 of the same article. BTW, I am using a dedicated subwoofer amplifier for my subwoofer(s). https://www.parts-express.com/dayton-audio-sa1000-subwoofer-amplifier-rack-mountable--300-811 Dayton Audio SA1000 Subwoofer Amplifier Rack Mountable. Model SA1000. It has a variable 24db/oct low pass crossover and a parametric equalizer to fine adjust the frequency response. George
  8. I searched the literature for comparing speakers using passive vs digital crossovers(processors). The first one is not an apple to apple comparison between Revel 106M vs NHT Xd Active DSP System. https://hometheaterhifi.com/reviews/speaker/bookshelf/revel-performa3-m106-2-way-bookshelf-monitor-loudspeaker-review-part-three/ The second one is a comparison between passive KEF LS 50 vs KEF LS 50 wireless(active DSP). https://forum.audiogon.com/discussions/kef-ls50-wireless-vs-passive I admit I am an old fashioned hobbyist who enjoys playing with surplus electronics parts. The speakers with passive crossovers allow me more opportunities to keep busy:) George
  9. Good question. I would probably try that some day. Interestingly, many expensive speakers such as Wilson and Revel still use passive crossovers while in theory they could use DSP and be done with it. I don't know if it has to do digital(DSP) vs analog(passive). What do you think? George
  10. Dayton audio recently introduced 2 new reference series 28 mm dome tweeters(RST 28F-4 and RST 28A-4) replacing the highly praised RS 28F-4 and RS 28A-4. The F version is soft fabric dome and A version is hard anodized aluminum dome. The RST 28F-4 and RST 28A-4) now have 92.5 db and 93.5 db sensitivity, some 3db more sensitivity than their predecessors. The combination of high sensitivity and the ability to cross low as 1400-1500 hz make them extremely attractive for DIY projects. Carspeak even recommended RS 28F-4 as a replacement tweeter for Advent NAL with highs extended flat to beyond 20k hz. I have been playing several reiterations of JBL 127 H-1/Dayton RST 28 F-4 for months. The latest crossover (GSL-A) represents the most balanced sound so far. The same crossover works also with RST 28 A-4. Both F and A versions are highly listenable.
  11. ligs

    Prototype or DIY?

    see the picture.
  12. ligs

    Prototype or DIY?

    The magnet of the unmounted tweeter was probably glued to the back of the woofer magnet at one time . I have seen this arrangement to cause less interference to the old tv or computer screen. The so-called bucking magnet also increase the magnetic strength of the woofer lowering the Qe. But I am only guessing.
  13. ligs

    AR5 pots bypass

    16 awg inductor will do just fine. If you worry about the small difference in DCR you can always add a 0.02 ohm resistor in series with the 16 awg inductor.
  14. ligs

    AR5 pots bypass

    I have a pair of 0.049 mh 17awg inductors(originally from Heathkits version of AR3a). I probably can help you on that.
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