John Albright

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About John Albright

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  1. I had 4 La Scalas in my HT for a while. The seats had to be moved to accommodate them, though, so finally I went with Heresies for the rears. It sure sounded good! If there is any way, the front 3 should be the same. Three Cornwall IIIs is not a failure. Nor is 5. Two subwoofers is just a good beginning! Don't think small! Since the plan of your room is square and 14.9', look for some attractive bass traps. You will have an impressive standing wave at 76 and 152 Hz. http://www.gikacoustics.com/wp-content/uploads/2015/09/GIK-244-Bass-Trap-w-FlexRange-Technology-Datasheet.pdf You can also build your own using thick rigid fiberglas, aka duct board and plans off the web.
  2. Thanks! Sent him an e-mail.
  3. So, what happened to the ad? I'd like to get some Heresy Theater Surrounds, or similar. Any way to get in touch with him?
  4. I have the same, or similar, subwoofer in my "music" room, an 11 x 20 bedroom, supporting a pair of KG2s and/or Auratone 5CTVs. For Heresies and realistic concert volumes, I'd recommend 2 of the Dayton subs. Then you will have excellent stands for your Heresies. You will also obtain lower distortion levels from 2 subs to better match the Heresies. Whatever route you take, you only need to point the squawkers and tweeters at your listening position. Congrats on retirement! Look in on the Cables, Coffee and Cocktails thread. Skip to the end, there's no hope of catching up! This morning's cup is a home roasted Kurundi Kayanza, medium roast.
  5. Not really, the bass horn is split and wraps around the Woofer Chamber, aka dog house. If you stick your hand inside around the dog house you will feel the sloped pieces that form the expansion of the bass horn, finishing with the roof of the dog house. Similar to a megaphone (conical horn), a horn just needs to have an ever expanding cross-sectional area. The rate of expansion defines the "kind" of horn, the length and mouth area determine it's lowest operating frequency. As I remember, the La Scala bass horn is an exponential (ly expanding area) bass horn with a cut-off of 70 Hz and a small mouth for its 70Hz. On the floor, in a corner will boost its output down to around 50 Hz. OTOH, I know of no other horn loaded system that is as small and performs so well. Once they become about 30 years old, the capacitors are likely to have moved off spec enough to warrant replacement.
  6. You should. That will eventually cause an audible noise. Wash, rinse, repeat on the other side.
  7. Yeah, the Frakenbolts haveta go. Yours are well past 1982, with the AL-3 crossovers. Look near the crossover in the edge plys for the serial number. You have the perfect opportunity to brace the mouth of the bass horns before refinishing them. Use excellent birch plywood. Here is a pic, supplied by HDRBuilder I think, of an experiment Mr. Paul did. Note that the braces are not centered, to prevent changing the resonance from 1 to 2x. This is what you should do. Mine were finished before I discovered the mouth resonance (at high volume) and I am not about to muck them up, now. I covered the front edge plys with a 3/4 x 3/4 strip of solid cherry to frame the grille and make it look nicer,
  8. Unused woofers returning energy to the room, delayed a few milliseconds does "sound" reasonable and believable. You could short the input terminals of unpowered (sub)woofers and dramatically reduce the effect. Surely the amp of a powered sub would would have low enough impedance to do a similar thing.
  9. OTOH, his HT peaks should be 105 dB above an average of 85 dB in a movie. 105 dB out of RF-7s will be around 4 watts/channel and possibly 16 watts/channel if he sits over 2 meters away. Since he has 11 channels operating, 16 watts/channel is waay high. If his 140 wpc receiver only produces 50 wpc, all channels driven at a desirably infinitesimal distortion level, he is still in Land Of The Giant(s) Overkill. No, you do NOT need a power amp. You may want one for its greater speaker control and lower distortions that are hard to measure and thus list on a spec sheet.
  10. http://www.greatplainsaudio.com/downloads/902series.pdf About $200. To cross at 500 Hz, this driver needs at least 18 dB/octave, 24 dB/oct would be better, or a higher crossover frequency. One of our forum members did extensive testing of the 902/511B and K-55-* on K-400 and 511B horns. I have found his data to be accurate enough for crossover design. The curve below peaks at 106 to 107 dB/w/m. Using those values, you can design a high pass crossover with a sag in it and a steeper than nominal slope and avoid either an L-pad, or autoformer while getting flatter response. My results were excellent with a Peavey FH-1 bass horn, other than the FH-1's horrid distortion below 100 Hz. Altec 902 on 511B.txt
  11. EVERYTHING resonates. Everything. The presence of a port is also irrelevant. A sealed woofer also resonates at the frequency dictated by the mass of the cone and the spring rate of the woofer's suspension and the air trapped behind it, just like the ported system resonates at the frequency dictated by the mass of the cone, the mass of the air in the port and box and the spring rate of the cone's suspension. The likely thing to happen is the unused subwoofer will absorb energy at its resonant frequency and it will be unmeasurable in the room's response. Why let it go unused? Multiple subs in different places evens out the bass response throughout the room. Mulitiple Subs - Number and Locations.pdf
  12. IEEE on K-400.zip
  13. Probably not, but Acoustastuf was designed for cabinet linings and was said to be several % better than polyester pillow stuffing at several times the price.
  14. Great Find! That is a high quality void-free plywood with birch veneer as the outer layer.