shivas or brahma?

[William from NOLA]

Yea i know that. I was just saying bc he seems like a beginner.
TEDD

me too

[6three6mafia6]

well i had 550 watts going my xxx at first and it would not move, i would have to put the gain and boost all the way up, with 800 it really moves with my gains and boost set correctly,im sure 600 could get it loud if you get a spl tunned box , better to have a little more than not enough.

[William from NOLA]

What box did you have it in and what were the two amps?

[audiobass10]

Although the xxx and Brahma are similar..its known that the Brahma can perform w/ much less than its rated power where as an xxx is more of a power hungry sub. I like what william's doing because it shows that you dont need 1kw of power to get pretty loud w/ the Brahma.

[Jonathan]

"This goes for every sub out there, not just the Brahma. This is due to mechanical differences in the boxes; sealed boxes have lots of backpressure to keep the sub's cone motion minimum as compared to a "loose" ported box."

That's a misconception. A ported box actually has more mechanical power handling than a sealed box anywhere above it's tuned frequency, and more internal pressure. That is the reason that ported boxes offer lower distortion than a sealed box above tuning, and the reason that their transient response and group delay figures are higher than a sealed enclosure. It's also the reason that SPL competitors use ported and exotic bandpass boxes for competition, because they can pack on tons of power on the subwoofer at the tuned frequency, you'll get loads of output from a subwoofer while the increased mechanical power handling keeps excursion low, meaning you can keep adding more and more power getting SPL, while still not stressing the subs mechanical limitations. If ported boxes were "looser" than sealed in such applications, then the subwoofer would reach its mechanical excursion limits with far less power and you wouldn't need 100,000 watts of power for an SPL competition system. The reason that ported is recommended over sealed for low power applications is simply because they are more efficient than sealed and you will thus get more output for the amount of power you're applying. The only time that excursion is higher with a ported box is when you go below the tuned frequency of the enclosure and the box loses dampling, and it performs similarly to infinite baffle after a certain point. The reason that the Brahma doesn't "need" it's full RMS rating in most applications is because the voice coil is designed to take more thermal power than needed in your everyday box. 800-900 watts is typically all you'll need to get the subwoofer to full excursion in sealed boxes with a .707 Q. More power in such a box will just end up in overexcursion and possible damage to the sub if you aren't careful. If you use smaller sealed or ported boxes geared more for SPL, you'll need more power, which is why they made the voice coil handle more thermal power. Other sub manufacturers tend to make the coils where they will handle just a little more power than needed for peak performance in a given enclosure, and leave it at that.

[William from NOLA]

I accidentally meant it as in terms of SQ, the sealed is more controlled. Woops. I should have worded that better and also reread the whole post I replied to up there lol. My mind works in strange ways... I start thinking one thing, then end up on the opposite end.

[Jonathan]

I understand, I was just making sure that people didn't think that ported boxes equaled less power handling or more excursion with the same power. It's just a general misconception that sealed=SQ and ported=SPL and worse SQ. Maybe your typical prefab box at Best Buy, but a well built ported box *usually* is superior in the area of mechanical power handling and thermal power handling (since air is able to move in and out of the port), and it offers increased cone control over a sealed box. The downsides are that the ported box doesn't mate well for a flat frequency response due to the cabin gain of the car environment due to cabin gain, in a room you can get a flatter response with ported since it doesn't begin rolling off until it's tuned frequency. Sealed excels for overall flat frequency response and responds more quickly than a ported, and that is the main reason a sealed box sounds more controlled, even though it isn't. There are two ways to look at transient response, how quickly the sub moves (advantage goes to sealed) and how quickly the sub stops (advantage goes to ported). Transient response by definition on the subject of speakers is the ability of a speaker to respond to any sudden change in the signal without blurring (smearing) the sound. A speaker that can react quickly to rapid changes in sound has "good transient response". So increased mechanical control (ported) results in a sub that stops quicker, so less overthrow happens. Sealed offers a sub that responds more quickly than ported, but the properties of the enclosure acting like a "spring" tends to result in more overthrow and increase distortion, especially at high volumes. A small sealed box increases control and mechanical power handling, but the tradeoff is that you lose low frequency extension and the sub responds slower. A sealed box too large will increase response and decrease power handling and control, at a certain point you eliminate the enclosures ability to assist the subs suspension and power handling dramatically decreases. Ported boxes have to be built well with a large port area in order to provide great SQ, if you don't you basically get the performance of a leaky sealed box and a lot of port noise. All in all IMO a well built ported box can sound just as good as sealed, it just takes a little more planning and taking your time building it. For optimum SQ I prefer the Aperiodic membrane, it increases cone control and power handling over sealed and creates a critically damped system that accurately tracks the input signal. You are "tuning" the membrane to mechanically dampen the subwoofer at it's resonant frequency, so it results in a very flat, predictable frequency response and a smoother impedance. It is less efficient than sealed and infinite baffle, that's the main tradeoff.

[armedforglory]

jonathan, did you used to be on the ecoustics forum along with Kiki/GlassWolf??

[Jonathan]

Yeah, I'm still on there.

[spkrman]

Good readin, and very true.

As always...

Its all install :)