Masterpiece LCR, Portrait LCR, and Sketch LCR: 50 – 250 Watts RMS set on THX at 80 Hz crossover.

A25 - A rear firing tweeter for the PHOENIX would increase the speaker's high frequency 4p acoustic output by 3 dB for an even more uniform power response. In earlier designs I actually used such a tweeter. Because of the physical size and separation of the two tweeters - in terms of wavelength - it is impossible to obtain a simple cos(a) polar response. See similar questions...

There are many ways to convert electrical energy into physical motion, and therefore into sound. Voice coils and magnets work well, as we know. Electrostatic hi-fi speakers that work on resistance are considered outstanding for smoothness and detail. Tweeters based on capacitive motion have many advantages, among them extreme ruggedness. See similar questions...

I give a formula in Ref. 2 and in Design Models A1 that relates the sound pressure level from a driver on an open baffle to the SPL from the same driver in an acoustically small closed box, assuming that both have the same cone excursion. frequency Fequal the SPL is the same for either driver arrangement. The open baffle driver output decreases at 6 dB/oct below this frequency relative to the closed box. See similar questions...

A28 - The shorter you make D, the distance between front and rear openings of the PHOENIX and H-frame woofers, the higher the frequency for which the rear wave adds in phase to the front wave, and the unequalized dipole output reaches its first 6 dB peak. Unfortunately, there is a resonance that comes into play before this peak. The cabinet structure between the driver cone and the cabinet opening forms an acoustic transmission line. See similar questions...

A30 - A dipole placed in a room corner should provide minimal excitation of room modes or resonances. The corner is a region of maximum sound pressure and it is well known that a typical monopole woofer in this location will couple optimally to all room modes. A monopole woofer would be a high impedance pressure source in the high impedance region of all wave modes (Z = p/v) and be optimally adapted to support them. See similar questions...

A34 - The low frequency roll-off of a woofer and its associated group delay are optimal, from what I have observed, when they follow the response of a 2nd order highpass filter with Q = 0.5. When a driver is mounted in a dipole W-frame or H-frame its mechanical resonance frequency Fs decreases to Fd, due to air mass loading, and Qts increases by a similar percentage to Qtd. For example, a driver with very strong motor, Fs = 18 Hz and Qts = 0.2 might have Fd = 16 Hz and Qtd = 0. See similar questions...

A39 - It is often assumed that excessive amounts of power are required to drive a dipole woofer, because of the necessary 6 dB/oct acoustic roll-off equalization and additional boost required for drivers with Qts below 0.5. In fact, equalization does not change the power requirement. It is a driver's cone excursion for generating a desired SPL which determines how much output voltage and current an amplifier must be able to provide. See similar questions...

This is probably the most commonly asked question on rec.audio, and also the most impossible to answer. The market keeps changing, everyone has different tastes, and no one has the time to listen to even 10% of the products available in any country. Also, many good products are only available in specific regions or countries. If you really want recommendations and are willing to listen to the opinions of others, check the past few issues of Stereophile Magazine. See similar questions...

Good question. First, electrostatic forces are weaker than magnetic forces. Therefore, membrane excursions are limited. Since acoustic energy is a function of the volume of air that is displaced by the membrane, limited linear displacement is compensated for by making the membrane area larger. However, this has a beneficial effect: the large membrane exhibits a more resistive coupling to the air. See similar questions...

Tweeters or full range speakers are normally in enclosed speaker cabinets. Building these speakers into a table near your ears cannot give you the quality of sound that headphones, stereo or surround sound speakers properly placed can deliver, thus tweeters or full range speakers are not built into these tables. See similar questions...

Nope. No tweeter is needed or desired. Tweeters reproduce hiss. Radio signals often have hiss. Sounds Sweet speakers do not reproduce hiss. See similar questions...

Yes. While it maintains the original "feel" of the original concave dome, its extended frequency response and lower distortion make it a bit sweeter, and contribute to more of what they call "air" in the high end sound. I don't usually push them aggressively when people are replacing their woofers since they are already spending a bunch of money to fix their speakers. I figure they can always upgrade their tweeters later. See similar questions...

This is not a big problem. All tweeters are still available on the market except for the Peerless MT 20 HFC and MT 24 HFC that were used in OA-4, OA-5, OA-6, OD-11, OA-12, OA-14, OA-116, OA-2212, the Pop-box and the Coal scuttle. Regarding these we recommend using the Peerless CT62 instead which is a recommended upgrade anyhow. In all other cases replacing the tweeters with new ones is possible but you should consider upgrading your speakers. No we don’t. See similar questions...

A patent has been awarded Sound Lab that describes and protects a method by which the single-frequency resonance energy of the membrane is distributed in a manner that equalizes for the loss of energy due to dipole cancellation (a problem with all dipole speakers). This development not only provides a flat, extended bass response but it also eliminates the undesirable membrane resonance peak. [Learn more] See similar questions...

Physics. The trend in the world of powered subwoofers is to have big numbers out of small cabinets, and it doesn't matter what happens to acheive that end. Thus you have many "audiophile" subwoofers pumping out dirty, overly EQ'd bass. In reality, if you want clean bass, you have to have the cabinet size to allow for sufficient loading of the woofer cone--that's the physics part. See similar questions...

The Executive Committee has selected the speakers for their international expertise. There will be : CEOs, Authors and Executive Coaches, Professors and International Experts. The speakers and their bios are presented in the Speakers section of this web site. See similar questions...