Be loud! Din pasiune pentru sunet

[asus]

...acuma depinde ce masina. a lui fiind cu hayon, se aude mai tare ca a mea de ex, unde e portbagajul izolat. sincer...i-am spus si lui, prefer 1*P1222 (in viitor sper 2*P1222), in incinte sealed pe la 50L fiecare....mai raman si cu spatiu de o plasa ceva acolo in portbagaj, macar de gura lu nevasta-mea
aaa, si legat de adi...eu zic ca mai bine mergea acolo la el un monobloc gen DLS cad11...si din cate imi aduc aminte, inainte a avut 1204BR nu BP...stiu pentru ca l-am intrebat cum s-a scapat de el ca vreau si io sa ma scap de-al meu

[rami2k6]

hello?

se poate sau nu sa fac portu de bass reflex gen 1204BR?

huffy cat e curieru pana in buc sau cat e totalu?

10x

[asus]

ia tradu-ti putin:
if you're building small, car sized speaker boxes, then the increased length of the ports is indeed a big problem, since you will need more port length than your box has room for!

There are currently three ways to combat this problem:

Use flexible tubing. Flexible tubing is designed to be able to twist and turn inside the enclosure, so that if your ports need to be 14" long, and the longest side of your enclosure is 12", you can just bend and twist the tubing in there to get it done. The bad news here is that this approach takes up an awful lot of interior space in your box, which you'd better account for, else your box will sound like crap. Also, that flexible tubing isn't very flexible. It has a turn radius similar to a school bus.
Use rectangular ports. Rectangular ports give you "more for your money" as far as length goes. What I mean by this is that using rectangular ports enable you to squeeze more "port power" into a smaller box. The reason for this is that rectangular ports can follow the walls of the enclosure (not unlike a maze) in order to acheive the desired length.The bad news here is that rectangular ports must be built into the box, and therefore require much more skill and equipment to accomplish. As with flex tubing, rectangular ports consume a lot of internal space, and so the entire design must be re-done to allow for the area displaced by the ports.
Run "external" ports. Yes, you can run your ports outside of the box (the box doesn't care). This allows for a minimal box size as compared to traditional ports. The bad news here is that your box will resemble a space-age life support system, and people will call you eccentric.
If none of the above options appeal to you, then you must go back to the drawing board and make the sacrifice somewhere else. Remember, a small box tuned to a low frequency will demand a large port design. It's that damned "trade-off" again. Yeah, you can have a small box deliver big sound, but, as you now see, it's requires more thought and more work. But, the good news is, it CAN be done.

You shouldn't try to make too long ports, because they must be very much shorter than wavelength of sound to be reproduced by the system. About 1/20-1/10 is safe factor. Otherwise, they start to behave like organ pipe, which is not desirable. If this proves impossible, then viable solution might be using passive radiator instead of the port. However, it has its own peculiarities, which you can see, when you simulate such a system.

[rami2k6]

cum s-ar impaca amplificatoru asta DLS/CLASSIC_CA12

http://www.be-loud.ro/produse/Amplificatoare/DLS/CLASSIC_CA12/

Cu difuzorul nostru?

10x

[mihai]

Pai nu prea bine, 1502d are o impedanta de 4 ohmi si CA12 e un amp mono care scoate 220W pe 4 ohmi.. CA12 ar fi bun pentru woofere pe 2 ohmi sau configuratii cu 2 difuzoare.
Uita-te la CA23, asta ar fi varianta perfecta pentru el (400W in punte la 4 ohmi).
http://www.be-loud.ro/produse/Amplificatoare/DLS/CLASSIC_CA23/

[asus]

pai daca pui bobinele in paralel, ai 1 ohm...ca12 are 500W la 1 ohm.

[rami2k6]

pai asta ma gandeam si eu sa il p[un la 1 ohm...

[mihai]

dar mai bine va functiona ca23 la 2 ohmi decat ca12 la 1 ohm..
daca suporta 1 ohm nu inseamna ca-i si place.. o asemenea impedanta solicita foarte mult statia si daca te uiti bine, cu cat impedanta e mai mica cu atat sunt distorsiunile mai mari.
cu CA23 in punte (in regim 2 ohmi) ai 0.2% THD si cu CA12 la 1 ohm ai 0,5% THD, cu 150% mai mult.
Si 0,5% e o valoare buna inca, JBL specifica puterea pentru 1% THD dar oricum... Daca nu te incanta controlul de faza e buna si CA23, are acelasi pret si putere similara... (2 x 30A ambele, pun pariu ca 99% sunt aceiasi statie)