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Re: Mis primeros altavoces de muy alta gama
[/IMG][IMG]Measurements, mid tweeter section Back to top Measurements may give us an idea of tonal balance of a system, i.e. too much or too little energy in certain areas. Measurements may tell us about bass extension if far-field measurements are merged with near-field measurements. In addition to this ports may contribute to bass extension. Most of us diy'ers do not have access to an anechoic room for full-range measurements from 20-20000 Hz. What cannot be seen is what kind of bass performance we get in a given room. Bass performance is highly dependent on in-room placement of your speaker and the same speaker can be boomy in one place and lean in another. Actual SPL level at 1 meter distance and 2.8V input is useful for en estimate of system sensitivity and combined with the impedance profile may give an idea of how powerful an amplifier is needed to drive the speaker to adequate levels. What measurements do not tell is the very sound of the speaker unless displaying serious linear distortion. The level of transparency, the ability to resolve micro-details, the "speed" of the bass, etc., cannot be derived from these data. Distortion measurements rarely tell anything unless seriously bad and most modern drivers display low distortion within their specified operating range. Many people put way too much into these graphs and my comments here are only meant as warning against over-interpretation. There are way more to good sound than what can be extracted from a few graphs. I think I speak for all of us doing speaker measurements when I say that we learn new things every time we do one. Every graph needs interpretation in terms of what it means sonically and how it impacts our choice of mating drivers, cabinet and crossover design.[/IMG]
[IMG]Left: SPL for 18WU/8741T00 on Jenzen mid baffle. This is the best response I've seen from this driver so far. I thought the 2.5 kHz dip was kind of intrinsic - and maybe it is, but on the Jenzen baffle we have a nice smooth response all the way to 6 kHz except for the usual 1 kHz rubber surround resonance. Right: Same driver on 25 cm baffle. I think this clearly demonstrates the importance of spending time on cabinet design. A lot of trouble can be avoided in the initial stages, where most diy speakers starts with a dream design and all hell breaks loose when the problems have to be fixed in the crossover.[/IMG]
[IMG]Left: CSD of 18WU/8741T00. The usual peaky response between 3 and 6 kHz really doesn't show up on waterfall plot suggesting little energy storage. Right: Having a stepped baffle can cause trouble for the tweeter, but this doesn't make trouble designing the crossover.[/IMG]
[IMG]Left: Response from M and T drivers driven from crossover. Right: Inverting tweeter polarity makes a deep suck-out around 2.1 kHz. Left: Individual response of drivers driven from crossover incl. summed response from same and inverted polarity. Right: CSD from MT driven from crossover. [/IMG]
[IMG]Left: Step response from MT section. Right:Final system impedance. In the critical area we have a minimum of 4.5 ohms impedance and 3.5 ohms around 400-500 ohms. Note the modest phase angles in the bass region thanks to the damping of the transmission line.[/IMG]
[IMG]Left: Vertical dispersion measured from T height to M height (center of drivers). Right: Horizontal dispersion of MT at 0, 10, 20 and 30 deg[/IMG]
CitarLlegados a este punto. vamos con las cajas que albergaran los filtros.[IMG][/IMG] [IMG]y si sois observadores vereis a la derechas las pruebas de color "que fueron el segundo asalto con mi mujer que se quejo hasta el infinito y mucho mas del olor que despiden los tintes" no sabia lo que le esperaba por que justo después vino el lijado.
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Esta fase fue la mas complicada. nunca había soldado con estaño bueno ni con estaño ni con nada , lo mas parecido era pegar cosas con pegamento, así que tuve que entrenarme soldando cosas antes de ponerme manos a la obra y hasta que no lo tuve claro no empece[IMG][/IMG][IMG]
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observareis que puedo seleccionar la frecuencia de corte para los agudos
En esta fase hubo gastos extra como fue una pistola de pegamento caliente y un soldador y estaño/plata de una cierta calidad.
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Iniciado por Yoyes
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[/IMG][IMG]18wu/8741T00 
[/IMG] D3004/660000 Tambien Scan-Speak
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[/IMG] por el cambio de color hubo que añadir una pieza cuatro centimetros para respetar las medidas de conduccion del aire en la caja de bajos.
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