8" Venom Subwoofer Enclosure

[mangrovejack]

Hi Guys,

I'm looking at getting the above mentioned 8" sub for use in my 5.1 system.

The T/S parameters are as follows:
SPECIFICATIONS
Nominal impedance: 4 ohms
Power rating: 100WRMS
Sensitivity at 1W @ 1m: 88.35spl
Voice coil resistance (Re): 3.5
Resonant frequency (Fs): 35.71
Mechanical Q factor (Qms): 2.408
Electrical Q factor (Qms): 0.457
Total Q factor (Qts): 0.384
Equivalent volume (Vas): 42.87
Voice Coil Diameter: 35mm
X max: 5mm
Magnet Diameter: 120mm
Magnet Height: 40mm


This sub is from Jaycar and they recommend the following enclosure parameters:

Typical application (vented box)
Box volume: 29.7Lt
Tuning freq: 35.62Hz
-3dB point: 40.49Hz

Cabinet dimensions (internal)
520(H) x 321(W) x 198 (D)mm
Port size 66mm dia, 217mm long (use our port, CX-2682)

Now I don't really trust their figures since they use the exact same enclosure dimensions with the 10" and 12" versions of this sub too.

I plugged the figures into WinISD and I came up with a design that had the volume at 40L, the tuning frequency at around 38Hz and the -3dB point at 35Hz (Using two 50mm ports at 163mm long each).

So would my figures work and sound alright or is there anything else you guys can recommend?

Note that I will have a low pass for the sub fixed at either around 86Hz or 100Hz. Which would be better?

Thanks.

[Volenti]

My advice would be to aviod buying any of the Venom subs, their looks write cheques that their suspension can't cash.

Step up to a 10'', there is a world of choice available in 10'' drivers, have a look at the other 10'' drivers available from Jaycar for starters.

[Collo]

GDay mangrovejack

I live in Newcastle and have been using the Jaycar gear for a couple of years now. I have used all their amps but only the 10inch titanium driver which has worked well for me, but is unfortunately being phased out.

I have a web site describing the subs I have built, and have had queries regarding the use of some of the other Jaycar drivers. In response, I have been putting together a comparison of their range in terms of Home Theatre usage.

I have just added the analysis of the 8inch Venom. Go to mydrivers page and select your driver from the list.

I found that it just didn't have enough excursion to be of much use.

If you are thinking of some of the other Venoms (which I haven't done yet), be aware that the 2005 catalog lists different excursions for each size as you would expect.

The 2004 version shows them all at 5mm. I wish they would lift their game on publishing specs - their new carbon fibre subs don't list Xmax and they're not on their website. Kinda makes designing something with them a bit difficult eh.

regards

Collo

[mangrovejack]

I was searching around via google and found that someone else recommended the following enclosure:

I'd tune at 34Hz in a 30L box and use a port 2.5" in diameter by 8.8" long. This will get you an anchoic 40Hz -3db point, or about 35Hz when loaded in the eigth space spatial condition. Its frequency response is dead flat, and will produce the best response in terms of bass extension vs distortion.

Does this sounds reasonable?

[mangrovejack]

And here's another recommendation:

I suggest thinking about a 4th order bandpass alignment, as follows:

Sealed volume = 18.0 liters
Vented volume = 12.5 liters
Fb = 65 Hz (3" vent that's 8" long).

[mangrovejack]

Collo, thanks for the link, made for interesting reading.

Do you know if they are still selling those titanium 10" subs for $49.95? If that's the case, then I should probably get that one.

[Collo]

Those titaniums are getting a bit scarce now. I was helping a bloke via email (in Victoria I think ) and he got the last one they had at his local.

I bought 4 through my local supplier and they ordered them in for me - yes at the good price. So if they don't have 'em in stock, get them to check with the warehouse

I still think they were the best driver they had!

Collo

[Madmike2]

No access to the XXLS subs from peerless for you guys ?? Rediculously tiny sealed enclosures , 13 mm Xmax , decent sensitivity ?

I shy away from anything with a cool name. I cant even look at myself in the mirror. I am all show and no go

[f4ier]

Madmike2, Peerless goods are also available in Australia... Only they're a bit costly.

There are some Titaniums still lying around in some JE stores. They're not bad, it's just that they've only got a few mm of linear Xmax.

You may want to look at a recent post about Ascendant Audio dumping XBL^2. US$100 for a 12" XBL^2-enabled sub!? You've got to be crazy (or a poor student like me) to pass up a deal like that. I wish I could buy 2 of those Atlas 12 subs

[tktran]

i've sent two emails to Ascendant Audio re. shipping to Oz, but never got a reply.

and even if they did send it, once I factor in shipping (~US$50 for the slow 6-8 week journey by sea), the cost takes a jump.

I've concluded that monster subwoofers are not really worth buying overseas, especially when we (Australians) have Peerless XXLS from WES.

Really, in terms of 8-12 inch subwoofers, the only reason I'd want something else is to save money, or go bigger (15+ inches).