Help needed for high power coffee table subwoofer project

[Jared]

he said 30 amp 120v outlet.

 

[Sixthofmay]

Sreten,

So you are saying a smaller box with a Q of .6 would be a bit better? I'm using WinISD (beta) to calculate the Q. I'd certainly like the smaller size. But this one page linked by Paul suggests .5 is better for my goal (high output servo-like performance):
http://members.ozemail.com.au/~joeras/sub_index.htm

Know of any other 4 ohm 15 inch drivers with 800-900 watts power handling that might be better? Preferably in the same price range, as I've already spent way too much money on this midlife crisis (Maggies)...

Planet10,

I'm trying to make it as close to a servo drive setup as possible (without a servo setup..). And my understanding is that you want a low overall damping factor to help achieve that. Thus the reason for a low impedance amp and thick low ohm speaker wires. Putting them in series would nullify the effect of everything else being low impedance. And I wouldn't be able to take advantage of the amp's maximum power out. It's hooked to a 30 amp 120 volt circuit (with the funny power plug and receptacle) so it's capable of max power. Yes it'll be somewhat less than 3600 watts actually getting to the speakers because of the amp's losses though. But that's ok. Should still be adequate.

 

[Paradise_Ice]

I dont understand why people want such large power rated amplifiers? 3 Kw power ouput, is not a usable power.

This is to much power for a drive unit to handle.
The wall sockets in the UK are good for 3120 watts typically.
David is right no amp is 100% or even 50% efficient really.
I have six Nad silverlines and i needed a new electrical system to run them,
normal wall sockets and standard wires are not good for such high current draws.
If your a crazy audiophile like a well know person on this forum!
I wont mention any names.

You could bypass the electric metre and go right into the main powersupply cable with the 90 amp fuse the size of a can of Coca Cola!

Only for the love of pure clean voltage of course! not for the money saving aspect!

You can have 21,600 watts, so if you do not have your electric show on or washing machine or microwave oven or anything with large current draw, you could have an amplifier with an ouput of some 10 kw, is that enough for you?

I do not recommend anybody bypasses there electric metres even for the sound quality benifits, its not safe at all, dont do it

 

[454Casull]

Some amps are over 85% efficient (see Tripath).

Also, many subs designed for car competition use can handle peaks of well over 3000W.

 

[Paradise_Ice]

Some amps are over 85% efficient (see Tripath).

How long could the sutain this output? not long i would imagine?

Also, many subs designed for car competition use can handle peaks of well over 3000W.

Peak power, plus not sensitive at all, dont believe high power ratings on car woofers, its a marketing thing, there only a few that can take very high current and there not cheap to make,
But ultimatly once again, they can not take high power for a long time, the whole thing is our tecnology is very poor and needs to change, i remeber somebody posted a thread about Class A amps being wasteful and for the rich people, as there so inefficient at only 10% fair point.
Speakers are the least efficient at only 0.5 to 3% efficienty.
I have in 20 years am not playing wth speakers!
some kind of bending wave technology! with out mechanics dont ask me how! i dont know yet.

 

[sreten]

Sreten,

So you are saying a smaller box with a Q of .6 would be a bit better? I'm using WinISD (beta) to calculate the Q. I'd certainly like the smaller size. But this one page linked by Paul suggests .5 is better for my goal (high output servo-like performance):
http://members.ozemail.com.au/~joeras/sub_index.htm

Well IMO Paul does not know enough about combined
filter functions to achieve specific frequency and transient
performance targets.

I'm saying a box half the size will probably be just as good.
A target of Q=0.58 will yield a Bessel alignment which has
linear phase response and excellent transient response.

Neither approach will yield "servo" performance, e.g. servo
compensation of voice coil heating effects obviously will not
occur, or compensation for distortion at high excursion.

The Bessel alignment is exactly the same level as Q=0.5
at 28Hz, and < 1dB lower at 20Hz, not much benefit for
doubling your box size, by 10Hz the difference is 2dB.

Compare the two in WinISD.

sreten.

 

[454Casull]

Peak power, plus not sensitive at all, dont believe high power ratings on car woofers, its a marketing thing, there only a few that can take very high current and there not cheap to make,
But ultimatly once again, they can not take high power for a long time, the whole thing is our tecnology is very poor and needs to change, i remeber somebody posted a thread about Class A amps being wasteful and for the rich people, as there so inefficient at only 10% fair point.
Speakers are the least efficient at only 0.5 to 3% efficienty.
I have in 20 years am not playing wth speakers!
some kind of bending wave technology! with out mechanics dont ask me how! i dont know yet.

Like it or not, those subs do exist.

And people will start switching over from Class-A amps just as soon as you make another kind that increases the sound level with less distortion. Not before. Besides, people who buy Class-A amps can definitely pay for the electricity bill.