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Hey dude..

It's been awhile since since we found something worth arguing...what gives?

 
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Also, what is the status of your fiberglass project? I am anxious to see it.

 
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Okay..well after talking to one of the tech's at Arc Audio..I found out why class D amps really suck for sound quality...Class D amps gain their efficiency by incresing output voltage while sacrificing current. THey put out the same wattage..but at a higher voltage. ..less current is why they stay cool.

For magnetic flux purposes a higher current has a stronger magnetic inductance. which offers more subwoofer controll.

HC amps are more Ideal for soundquality when it comes to subs. HC amps can get pretty toasty, however the voltage output is lower and amperage output is higher. This offers a stronger magnetic pull.

The woofer of the sub is much quicker to reverse directions and thus will have more linearity and faster response. Class D amps..with their higher voltage outputs offer less subwoofer control. It takes the woofer longer to slow down and reverse directions. For SPL this is somewhat a good thing. with the cones slower change of direction the cone travels a little further offering a tad more excursion.

This is why most class D amps offer what seems to be more power than the equivalent class a/b amp. However..there's a noticable sacrifice in slew rate (volts/millisecond) Class D amps have rather slow slew rates...(speed at which polarity is reversed).. the higher the vltage output...the slower the reaction to change polarity in the transistors.
with HC amps.. there is less voltage so the transistors are able to change polarity much quicker..

cool to know

 
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Wow, that's really interesting to know. How about the Class T amps, what's the story behind them? I can't find that thread about the Blaupunkt Class T amp, but i remember you mentioning that it wasn't good for whatever reason.

btw, since you guys seem to have a little time on your hands, I have a question, will a 2" PVC port have a lot or port noise problems? what can i do to reduce the noise? It's just temporary until i can get my hands on a Lightning Audio port flare which i've heard helps. I don't want to step up to 3" yet, I don't know if there's enough room in the box [IMG]i/expressions/face-icon-small-tongue.gif[/IMG] Thanks [IMG]i/expressions/face-icon-small-smile.gif[/IMG]

and sorry for interupting your thread

 
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well a 2" port is really small.. basically take a file and round the inside edges..and angled surfaces can cause whistling. if it's only for a 10" sub you shouldn;t get much port noise..what frequency is it tuned to?.. Generally only frequencies below port tuning tuning will cause noise..

 
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It's only an 8 inch sub [IMG]i/expressions/face-icon-small-wink.gif[/IMG]

0.787 ft^3

34.34 Hz

(1) 2" port 7.48" long

this is just what WinIsd is telling me [IMG]i/expressions/face-icon-small-smile.gif[/IMG]

thanks!
-Ed

 
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Oh..okay.. a 2" Port is plenty... you'll only get port noise below the tuning frequency. Just round off the edges of the port and you'll have no worries

 
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Awesome, thanks Mohawk!

 
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you say you were gona be busy moving, and ive been busy with my box, and my new job, between which take up so much time its rediculous....

 
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honestly? eveyone says that! ppl at my shop, ppl at the hardwarte store, friends, neighbors, everyone is "anxious to see it"

maaaaaaan IM the one whos anxious to see it! jeez, workign so hard to get all the s h i t together, and the terrible thing, is i left my digicam 200 miles away, so i only have several week old pics ;_;

www.calpoly.edu/~sciccare/trunk

old pics, youve all seen them before.

I pulled the car apart to get teh baffle in, when i had a sudden rush of genious, the whole box is redesigned, im trying to keep it a secret for the time being, so up teh "oh s h i t" factor when its done, im reserving all day on fridays to work on it, since i work 5 days a week and no longer have the time to work on it as i did (at least teh hard part is over) but im working on teh MDF portion fo the box right now, port problem i just solved, now i gotta get it to physically fit, then i have to figure out some fiberglass magic, this box is going to test teh limits of what i know about glass, i cant wait to have it all in and running!

i expect to be done with the box by late september/ early october.