My first home theatre build, need help

[SubNit 10+ year member]

Well, wait a minute, you didn't give me an inductance value. If you could find me a Le value, that would make this a lot more accurate. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Having trouble finding that info. How criticle is this value? If I can't find it will it make a big difference?

 

[joeybutts 10+ year member]

PV, what program are you using to model it up?

 

[SubNit 10+ year member]

Yeah man I can't find that Le value. If you can't model without it then I understand. But if you could just point me in a good general direction that would be awesome FYI I'll only be powering it with about 500 watts

Thanks

 

[PV Audio 5,000+ posts]

Having trouble finding that info. How criticle is this value? If I can't find it will it make a big difference?

Inductance is at the same time unimportant and very important. For just a speaker paramter, it's incredibly important as a lower inductance means the signal can quickly shift from positive to negative, thus giving you a better transient response and low group delay. It also helps you know when and where the upper bandwidth for the speaker is. However, in an enclosure, it isn't vitally important, but it's still useful to know.

 

[PV Audio 5,000+ posts]

Having trouble finding that info. How criticle is this value? If I can't find it will it make a big difference?

Inductance is at the same time unimportant and very important. For just a speaker paramter, it's incredibly important as a lower inductance means the signal can quickly shift from positive to negative, thus giving you a better transient response and low group delay. It also helps you know when and where the upper bandwidth for the speaker is. However, in an enclosure, it isn't vitally important, but it's still useful to know.

 

[PV Audio 5,000+ posts]

Having trouble finding that info. How criticle is this value? If I can't find it will it make a big difference?

Inductance is at the same time unimportant and very important. For just a speaker paramter, it's incredibly important as a lower inductance means the signal can quickly shift from positive to negative, thus giving you a better transient response and low group delay. It also helps you know when and where the upper bandwidth for the speaker is. However, in an enclosure, it isn't vitally important, but it's still useful to know.

 

[SubNit 10+ year member]

So will you be able to provide me the info to build atleast a decent box? I'm still searching for that value but no luck

 

[SubNit 10+ year member]

So I had another source give me what they said were some *closer* t/s parameters

Re 6.2ohms

BL 28tm

Mms 260 grams

Vas 90 liters

Cms 100uN/M

Fs 31Hz

Qts 0.37

SPL 90dB

I'm ready to start building ASAP so if someone could help me out I would appreciate it. Thanks

 

[hzsogood 5,000+ posts]

I had a dayton mkIII titanic, and imo it ******.. couldnt build an enclosure that came even close to an exodus audio tempest.. Which is now in a 8 CF enclosure tuned to 18 hz run off a PE 1000 watt plate amp.. Car audio subs just are not made for the HT world man..

 

[hzsogood 5,000+ posts]

Bigger is better, lower is better. That means bigger cone size and lower resonant frequency. These speakers need to reach down below 20hz with authority unlike in car audio. If your speaker's Fs is around 30-35, by the time your 15hz depth charge explosion comes, your speaker will be about as torn to shreds as the submarine in the movie. For that reason, you typically need big drivers with high compliances and moving masses as Fs is an inverse relationship of the product of the compliance and the moving mass. If you want, you can add mass to the rear of the cone which has been done before but I would generally just recommend that you use a larger sub with a decently high Cms and Mms, or just a low Fs. In this case, Qts is critical to look out for. Unlike in car audio, if your Qts is .8, don't even THINK about putting that into a ported box. That thing will flop around like a dying fish. Instead, you will need to follow the >.7 = sealed and

YGPM

 

[SSS 18734 5,000+ posts]

If you're looking into a cheap power source, look into a Behringer EP2500, or the new ones that recently came out. You can get them used on Ebay for $200 or so.

Tons of power for dirt cheap. I run my pair at 8 ohms bridged for hours at full capacity and I really can't complain. Just keep them in another room - they're a bit loud, like most SR amps.

 

[SubNit 10+ year member]

If you're looking into a cheap power source, look into a Behringer EP2500, or the new ones that recently came out. You can get them used on Ebay for $200 or so.
Tons of power for dirt cheap. I run my pair at 8 ohms bridged for hours at full capacity and I really can't complain. Just keep them in another room - they're a bit loud, like most SR amps.

Thanks for the heads up. Been looking for an amp

 

[hzsogood 5,000+ posts]

Thanks for the heads up. Been looking for an amp

Used the ep2500 for a while with an external low pass filter

 

[SubNit 10+ year member]

Still need help on the enclosure.......

 

[PV Audio 5,000+ posts]

I had a dayton mkIII titanic, and imo it ******.. couldnt build an enclosure that came even close to an exodus audio tempest.. Which is now in a 8 CF enclosure tuned to 18 hz run off a PE 1000 watt plate amp.. Car audio subs just are not made for the HT world man..

No, and I mean this with all due respect, you just don't know how to design a home audio subwoofer enclosure. Car audio design techniques do not carry over in the slightest.
The Titanic is simply a superb home theatre speaker. The tempest is as well, yes, but the titanic is nowhere near a poor driver. I have used one since 2004 on 1000W daily in the home theatre at parents home in an enclosure I designed and it will knock pictures off the walls at moderate volume. It's down to the enclosure, my friend, not the speaker itself. The Tempest (I have owned all Adire drivers aside from the Maelstrom) is a great speaker, yes, but isn't lightyears ahead. I'm not saying I'm some master enclosure designer especially since I designed that particular one when I didn't even have a drivers' license, but it's still to this day quite decent. Read the reviews for the driver and note that they all say the same thing:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-420&vReviewShow=1&vReviewRand=882301

Oh, and the Dayton is about as far from a "car audio" subwoofer as you can get, so you can get that nonsense out of here right now. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif