11 replies to this topic

[VIP Silvia]

Ok after having a good chat with Adrian from Car Accessory Installs about RF Punch 6.5" subwoofers and fully active front stages, i have considered it.

So consider this

I am soon to be the proud owner of an Alpine CDA-7897. This can be set to full active meaning the rcas aren't front/rear/sub they are actually high/mid/treb. so doing away with rears altogether.
Adrians car runs a setup similar to this (he has 7998 and 3 way front stage, currently putting the RF 6.5" subs in!

So by getting the splits i want and ditching the crossovers, and using the RF subs do any of you guys think i will have a pretty mean front stage.

I know that then i will need an amp for each speaker so 6 channels altogether, or 5 channels and have the subs mono, but the HU allows for stereo or monoaural Sub output, so would i be better to go for the stereo set up??

also what sort of power rated amps should i be looking for seeing as the splits are rated at 100wrms (don't know what the individual rating for tweets and mids are) and the RF subs are rated at 150wrms each.

I am willing to buy amps to run them all, but i don't want to waste money on an amp that is way too overrated for what it is doing, ive got better things to waste my money on then. I am looking at V12 amps at the moment as they seem fairly good

I will try just normal setupand fully active with my current splits and see how they feel. but its not gonna give me an indication cos they are nothing in comparison to the splits i will be getting

[shiny_car]

so are you going to use the RF subs with the infintiy 6.5" splits?

what bandwidth (freq range) will each driver be given do you think?

one problem could be getting the subs to play subbass effectively:
*door cavity as the enclosure: ideally should be very solid and sealed, but difficult to achieve
*door rattles and resonance could be a problem with subbass

if you are going to use the RF subs for midbass drivers, i just wonder how well they will perform with the higher frequency midbass (ie: up to 500Hz or wherever the midrange will take over). subs typically aren't designed to play that high with much fidelity, although these RF drivers may be ok (i don't know them).

lastly, what are you hoping to achieve here that a dedicated boot-mounted sub won't achieve? again, if it's more midbass upfront, then perhaps there's better drivers for the job? it may be worth waiting to hear how this guy's setup turns out.

powerwise, i'd be thinking along the lines of 50~100WRMS on tap for the midrange/woofer and tweeter. then 100~150WRMS on tap for the subs.

interesting setup, so look forward to hearing of the results.

good luck

[VIP Silvia]

Well these are a proper subwoofer even though they are 6.5" so you can do what you want with them sealed, ported what ever. I think the specs say a .32 cuft enclosure.

I will still be running a boot mounted sub (IE 12.1D infinity)

what i am meaning of this setup is a 3 way setup (now im not sure wether to get 6.5 or 5.25" splits) to get sub bass up on the front stage.

its not gonna be driving earthquaking sub frequencys, more like have the boot sub as the main low freq and have these 6.5" subs as fill for the front and crossed over bit higher than the main sub.

I will definatelly wait to see adrians setup with these in it before i lay my money down

Just open to arguments before i splurge in my wallet.

Also im no longer inporting the MRP-M350 amp as adrian is getting them in for less than i was getting them for and has them in stock next week.
jeeze they are an improvement!!!

[Walkinshaw]

might i sujest, rather than a 6.5" sub, run a dedicated 8" Midbass driver per door in stereo(Vertis. Morel, ID, Orion, Dynaudio etc).

[shiny_car]

Quote

Originally posted by Sr20detrx:
what i am meaning of this setup is a 3 way setup (now im not sure wether to get 6.5 or 5.25" splits) to get sub bass up on the front stage.

which is part of my query. coz you are suggesting the RF sub will in fact be used as a midbass woofer. which to me is not ideal for that particular driver; that is, i don't expect it's designed for midbass so much as subbass. it may struggle to reproduce 500Hz with much clarity. then again, as i previously mentioned, i could be wrong, and what adrian has in mind could work nicely.

i suppose auditioning it will be the proof of the pudding.

and yes, walki's suggestion was what i was politely trying to avoid suggesting. sceptical bastard.

[Maz]

Definitely box those subs, they'll sound shocking in the door. go with the 6.5inch mids, and have the subs play a very narrow frequency range, 60-150hz.

putting the subs in a smallish box sealed box should make the bass roll off pretty quick, however i would get a 2 channel amp for just the front subs, and run the subs on high pass at the lowest possible seting. Then use the headunit low pass to make teh subs play a small frequency.

If you go active you'll be able to cross the tweeter over pretty high, around 4000hz which will improve power handling dramatically. That will be very loud, same with the midbas driver

[VIP Silvia]

Well i thought about 8" subs in my doors... but you should see my doors!!! or lack of space!

Yeh i was thinking of running a low pass to them, between the main sub and the midwoofer.

It says they need about 0.32 cuft sealed box, which i would think is around 9 litres (correct me if im wrong)

at the moment the pods are looking to be massive in all aspects.

I am thinking maybe even the Kappa Perfect 5 1/4" woofers might be even more apporpriate for the mids instead of the 6 1/2"???

Before i do any of this i gotta convert my doors to power windows, cos the winder is mm's away from my pods now!

anyone got a powerpack nissan bluebird that they wanna part the electrics and glass out of??

[shiny_car]

Quote

Originally posted by Sr20detrx:
It says they need about 0.32 cuft sealed box, which i would think is around 9 litres (correct me if im wrong)

yep, 9L is about right.

note the other concern is not so much the enclosure size as much as removing rattles from your doors. get those mofo's up and running and you'll want some very 'dead' doors.

Quote

I am thinking maybe even the Kappa Perfect 5 1/4" woofers might be even more apporpriate for the mids instead of the 6 1/2"???

for a dedicated midrange driver, i agree the smaller one will be better. the smaller, lighter cone will make for slightly better dynamics.

so where you won't need them to reproduce midbass, the smaller driver should be better for midrange.

[VIP Silvia]

Yes going to have to do a bit of cutting into the doors boxing SDing. the specs on this sub say it will work in a sealed enclosure between .1 and .32 cuft big, they also said .25cuft was the best for tradeoffs

is bigger better for SQ? or should i be going for smaller, i was thinking .1 is too small in my opinion. opting for the .25??

suggestions?????

I also ordered today my new HU. Alpine CDA-7897!!! can't wait pitty it won't be here for Burnie Car Show
Gives me more time to get my system working

[VIP Silvia]

Also i am looking at amps now to run all this. (geeze its good to have some money for a change!)

I am looking at alpine V12 range, cos thats in my price range and they look pretty spiffy and sound good too, and i can get them at a good price.

[shiny_car]

Quote

Originally posted by Sr20detrx:
the specs on this sub say it will work in a sealed enclosure between .1 and .32 cuft big, they also said .25cuft was the best for tradeoffs

is bigger better for SQ? or should i be going for smaller, i was thinking .1 is too small in my opinion. opting for the .25??

generally, bigger is better for low-end response.

but in your situation, i think you are chasing more midbass than subbass. so a smaller enclosure will be fine, if not better. however, it depends on the response curve, which may be a bit more 'peaky' with the smaller box, manifesting in slight boominess. whether that's bad will depend on where you'd expect that peak (if any) and whether it's within the bandwidth you're wishing the sub to reproduce.

so you need to consider:
*bandwidth for the driver
*frequency response curve for the box size
*thiele-small specs to help model the resp curve

plus of course a freq curve on a computer doesn't always reflect how it will be in a car, where the accoustics can boost low-end response in particular.

in the end, you may find you need to heavily EQ the setup for best results.

do you get the sense that i'm a bit sceptical?

good luck. don't rush into it. audition the setup in the car your friendly retailer is building first before committing.

[Dr DJ Choss]

Go the active set up but keep your front stage all stereo, including the midbass. Sound below about 100hz you can do mono.

Rich