Octane-R 15.0.1 driving 12" RSD DVC , 4 Ohms or 2 Ohms

eyesofra · Post by **eyesofra** » Mon Mar 05, 2007 11:07 pm

Hi guys,
I ordered a Octane R 15.0.1 online and was wandering which would be the best way to wire my 12" RSD DVC to the amp.
The driver is in a sealed 1.2cuft but i might be moving to 1.8cuft just for the sake of trying it out.

The Amp spec says:

RMS 500w at 4Ohms
RMS 1000w at 2Ohms

So should i go for 4 or 2 ohms ?
Is this amp really stable at 2 Ohms ?
What bout the sub , would it be able to handle the octane's 1000w ??

Pls advice, thanks guys.

Post by **Bfowler** » Mon Mar 05, 2007 11:21 pm

the DVC can only be wire for 2 or 8 ohms, so you will want to wire it parraell.

it will take the 1000 watts.....

and more...

Post by **stipud** » Tue Mar 06, 2007 7:57 am

Agreed, 2 ohms and 1000 watts should be no problem for either the amp or the sub. I would personally mount the sub in a bit smaller of an enclosure, but that's about it.

(PS: removed your other thread since both questions were answered here

)

eyesofra · Post by **eyesofra** » Tue Mar 06, 2007 8:45 am

thanks for the "sound" advices guys..

stipud, when u said " a bit smaller of an enclosure " , were you indicating the 1.2cuft sealed or an enclosure much smaller to that ....

Post by **Bfowler** » Tue Mar 06, 2007 9:03 am

1.2 is as small as you would want to go.

the box specs on that sub range from 1.2 to 1.8. with that much power you should stay on the smaller end of that spectrum to keep the woofer from reaching xmax at too soon

Post by **stipud** » Tue Mar 06, 2007 10:20 am

Agreed, 1.2 would be perfect.

eyesofra · Post by **eyesofra** » Tue Mar 06, 2007 11:47 am

now i get it....
its never one enclosure for all rite..

ok, i guess i've gathered most info to install my system once the amp arrives.

One last thing , should i adjust my gain for a full-blown 1000w
( squareroot(1000*2) = 44.7V at speaker output) or adjust it for something a little lower , 600W perhaps ?

sorry to keep on bugging on the same issue but i'm just a little worried i'll burn out my subs with so much power.

(well these subs are expensive back here

Thanks for all the input so far guys,i almost complete with all ur suggestions.

Regards,
Amuthan

Post by **Bfowler** » Tue Mar 06, 2007 12:18 pm

do you have the LPL with the amp?

if so, i would definitely tune it for full output, and then you can use the LPL to attenuate from that.

FWIW PG hooked a rsd12 to a Carver pro ZR1600 (1200@8ohms)

and let it play on sitting on the where house floor for about 2 days. (no box)

it was fine.

just keep an ear out for distortion, and you will be fine

eyesofra · Post by **eyesofra** » Tue Mar 06, 2007 12:38 pm

thanks bfowler !
rsd is definitely one hell of a beast....
yes i do intend to get the LPL hooked into the system,and i'll keep ur advice in mind when turning up the volume .

err jsut wandering..does it make a difference trashing the sub in an open baffle and in an enclosure...
i mean which would be more stressful for the sub, in terms of eating all the power feed into it??

Post by **stipud** » Tue Mar 06, 2007 1:26 pm

eyesofra wrote:err jsut wandering..does it make a difference trashing the sub in an open baffle and in an enclosure...
i mean which would be more stressful for the sub, in terms of eating all the power feed into it??

Open is much harder on the speaker. A sealed box will have a vacuum in the chamber when the speaker pulls itself forwards, and it will become pressurized when it goes back. This air pressure helps keep the suspension from having to hold the entire load of the speaker at high output.

eyesofra · Post by **eyesofra** » Wed Mar 07, 2007 8:54 am

hi again ,

finally the amp arrived and all hooked up. So far so good but i haven actually "played" it , waiting to do that tom .

Guys just a couple of questions on the amp Xover/sub filter frequency settings.
What would be a proper frequency setting to start with for this amp driving the RSD12" in a sealed 1.2cuft ??Should i set it like 35Hz / 80Hz

Secondly , i'm been adjusting the pots on all my amp before this assuming one thing , that they linear or directly porportional to the turning of the pot.

What i'm trying to say is this, take this amp for an eg,
it has xover frequency starting at 30Hz goin up clockwise all the way to 300Hz.
Would it be correct if i say , turning the pot halfway sets the frequency at :
(300-30)/2+30 = 165Hz at mid
(300-30)/4 +30= 97.5Hz at a quarter of turn.

If yes that would mean the same concept applies to all the pots rite ?? (bass boost,sens,xover,subsonic)

Also 4gauge wire enough to power this amp ?

Do advice me on how to go bout on this guys.

Thanks a million.

N/B : Just to share my shopping experience. Ordered the amp and a 4ch 5m streetwire ZN9 from techronics.com.
They are great ! Fantastic customer service and immediate product delivery.
Prior to that, called up woofersetc.com, they talked as if, i just asked some of their products for free ! Definitiely not friendly,maybe their concept for international customers. Sorry if i offended any parties here just sharing my experience for future shoppers.

Post by **Bfowler** » Wed Mar 07, 2007 9:34 am

They are NOT linear. there is a small picture floating around that i will try and find for you that displays how the pot distributes the frequencies.

4 gauge will be fine, even at 2ohms, that is a pretty efficant amp

as far as which frequency to tune to, i would set the subsonic to around ~25 and the LP just set by ear. i like it below 60, but that is just personal preference, tune to your tastes

eyesofra · Post by **eyesofra** » Wed Mar 07, 2007 9:55 am

thanks Bfowler,
( u've been of great help throughout my system setup,appreciate it a lot)

wow,looks like i've got it wrong ...the pot adjustments.
that picture u mentioned would be great help since i've got zero idea at this point on how the frequency distributes....

do they have any kind of basic guidelines to follow regarding the pot adjustments...none in the amp manual for sure...

regards,
Amuthan

Phoenixcolt · Post by **Phoenixcolt** » Wed Mar 07, 2007 9:59 am

Are the knobs on all of the PG amps not linear?

Because if not, Imight have to adjust some stuff differently as well.

Post by **Bfowler** » Wed Mar 07, 2007 10:26 am

heres the pic:

it is from the PG FAQ on their website, under the ZX amps.

Phoenixcolt: im am VERY sure your amps, as well as the octane uses this same brakedown

Post by **Bfowler** » Wed Mar 07, 2007 10:29 am

wait, that isnt the same as the octane crossover....

eyesofra, i know that the octane crossover isnt linear, but i dont know how it breaks down either, maybe you can creat a new sacle from the above picture

600 ~is to~ 70
----------
300 ~is to~ 45

eyesofra · Post by **eyesofra** » Wed Mar 07, 2007 10:49 am

thanks for that bfowler,
ill scale it down, but i just hope scaling it down works since the entire thing is not linear.

I will also try to work it out based on the xenon series xovers points since its given on their manual.

I've mailed the PG tech support regarding this . Hope to see a reply soon.
Will post all the finding soon.

I really dont understand why dont they just put in a adjustment figure such as one above in their amp manuals.

Honestly most of the times i just wish there was some frequency labelling on the amp or manual, cause using ears to do this is just too difficult at sub frequencies.

If i'm not mistaken Erin used to be in this forum rite, would be great help if he can guide on this.

Post by **Bfowler** » Wed Mar 07, 2007 11:03 am

he still is, just not as often. hes a busy guy now that its not his job to be on here anymore

eyesofra · Post by **eyesofra** » Wed Mar 07, 2007 11:07 am

ic, well his suggestions would have been helpful.
I'll get back once i'm done with this scaling down thing.

Post by **VW337** » Wed Mar 07, 2007 5:39 pm

FYI the XO is linear but not in the fashion most think, it is by octave not straight line numbers.

Post by **Bfowler** » Wed Mar 07, 2007 5:49 pm

VW337 wrote:FYI the XO is linear but not in the fashion most think, it is by octave not straight line numbers.

i know, but....thats what he was asking

eyesofra · Post by **eyesofra** » Thu Mar 08, 2007 7:51 am

VW337 wrote:FYI the XO is linear but not in the fashion most think, it is by octave not straight line numbers.

Hi VW337,
can you pls elaborate on this.
Its linear by octave ???

mind me if i'm wrong , but isn't the octave figure in filters basically a description of the roll-off sharpness .
Of course technically this explanation would be much longer, i'm just trying to quote its end purpose...

So how does this relate to a linear motion of the xover adjustment pot..??
Does it turn on a Logarithmic scale ??

Pls explain cause this info would be very useful for me and i'm sure everybody of the same interest.

Thanks again

Post by **Bfowler** » Thu Mar 08, 2007 9:12 am

octave refers to a musical term. when your amps says "18db per octave" that means ever octave the hz increase, the output sees a 18db decrease

sooo....lets say you set your crossover at 50hz. going up one octave is 100hz. that means at 100hz your output is 18db less then at 50.

when you set your subsonic to 25hz. one octave down is 12.5hz. so you have 18 db less output at 12.5 then you did at 25.

of course this only refers to the signal of the amp. speakers themselves have natural roll-offs also

Post by **VW337** » Thu Mar 08, 2007 10:34 am

An octave in musical terms is the halving or doubling of a given frequency.

40>80>160>320>640>1280>etc......

In most cases the XO's are labeled at the nearest whole figure so 40-400 or 40-600 is going to be a typical labeling. So you look at the octaves on a linear scale and the label says 40-400 the mid point should be in the low 100's and ~3/4 point would be near mid to upper 200's.

Hopefully this helps.

eyesofra · Post by **eyesofra** » Sat Mar 10, 2007 10:12 am

Hi again guys,
i've sketched down a xover filter pot guide based on all the input by our gurus here and of course with some googling effort...

The frequency points are linear but on the log scale .
I adjusted my amp today using this and of course by listening and i guess it worked.
Pls comment on the diagram.

Thanks guys