Recent content by thch

oh, and the listening, the phase shift will be the most difficult thing to listen for. basically, most people don't set the crossovers up very well, nor the gains. this leads to a bit of a difficulty in even finding a case where the benefits are obvious. if you didn't understand the above...

Adjustable phase is intended to aid in blending the subs to the midrange speakers, or act as a crude "delay" element. first, you might like to understand phase. phase can apply to any periodic waveform or sequence. eg: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 ... a 180deg phase shift would...

I've had several notes about this and related subject. most are: Comments on Gains, Measuring Power, DMM, Oscope, and Clamp - Realm of Excursion on a side note, i think 80% is a bit above the maximum efficiency of a classB output stage unless you drive it into clipping. the class B amp...

its partially the efficiency rating, but also the efficiency when in use. class D tends to be pretty efficient from 10% to 100% rated power. class AB tends to have ok efficiency at 100% rated power, and really poor efficiency at lower output power. the result is that turning the volume down...

you could always see if TI has samples of the part as well. not sure, but generally the worst case is you pay shipping. I've had good luck with TI for samples -- $0 and 2day shipping.

i'll note that the smaller, similar looking things on the right are not actually the same device. the ones on the left are kinda like gears which convert high torque/low rpm into low torque/high rpm. (or low voltage/high current into high voltage/low current) the ones on the right are kinda...

agreed, and as always remember that sound is based on pressure and not specifically on the direction a speaker is facing. its all too easy to confuse the effective "direction" of a speaker based on the angle it is mounted. not sure what you mean by "geometric center", but the geometric mean is...

make sure the speakers are not connected to the amp, and that you're not touching them. if they are connected to the amp, then you will be measuring something amp related. if the amp isn't turned on (or really, even if it is), the result will be off as the DMM will be attempting to measure the...

I've built some crossovers similar to that. its a fairly classic design. the issues you might find are: 1.) you need some power supply. that design wasn't meant to be run from 12V. 2.) this filter isn't adjustable without changing components. if you are interested, I can explain the...

these are likely based on boost converters or a handful of other designs. an issue is that you're talking about a HUGE amount of current, making this a bit less accessible. the real issue is that many amplifiers have low-cost "unregulated" power supplies. such supplies have many good features...

a bit lacking on specifics. a more technical class might go into detail on the box and speaker selection. or more basic, the properties of audio. an english paper might focus more on persuasive arguments about audio as a hobby. a public speaking topic might work well with social issues, such...

some DMMs will have a zero function. it might be labeled "relative" or "delta" or have a triangle (delta) symbol.

that doesn't seem to be looking at the amp's output, but rather the amp's input.

this is of use -- a rule of thumb is that for every 12dB/oct of difference between the HPF and the LPF, the phase of one should be inverted to correct for that phase shift difference. the higher slope filters will introduce more phase shift than the lower slope filters. the acoustic phase of...

there are two notes -- DC is the average value. normally over the entire signal, but for practical use it is just the average over some "long enough" time. the real part of the "clipping is DC" vs "clipping is AC" is based on what "long enough" means. if you look only at select parts of the...