stevencotton

Since I plugged my 10" Infinity into my Rockford 160.2, I get the volume I want but it sure seems to be a bassy amp. I have the head units bass setting to minimum (Sony CDX-600R), creating a bit of a frequency gap which I don't like. Anyone else got a 160.2 they find a bit bassy? Don't really know how to combat it - unless of course I just need to dynamat the boot to stop it booming so much?

Steve.

john banks

Perhaps you need to give your main speakers more power? How much do they get now and what are they?

kryten

what box is the infinity in?

sealed/ported? is it the recommended size?

'booming' is often a crossover, phasing or box problem ie the sub is doing too much work too high up the range.

rockin'Ru

I agree with kryten.If you're having problems with this setup,it must be either your fronts aren't up to snuff or the Perfect's box isn't perfect.

stevencotton

The fronts do need upgrading, still running those 4" Infinitys, is possible the HU I ran them off clipped prior to me amping them. Infinity sub is in a pretty normal looking ported (at the top unfortunately) box. I'll check the phase but I made pretty certain when I put it all together everything matched, but I'll swap polarity and see if it makes a difference, running bridged on internal amp crossover. I'll also try changing the way the box faces, see if I can get it to port into a larger area (currently it blows against the bottom of the rear shelf). I never noticed it before I got the new RF amp, perhaps I'm just not used to it being that loud ... that and a combination of the All Is Full Of Love remix that was on the Bjork CD that came with The Times last weekend ... I'm also looking for a nice tidy way of securing the box in the boot and not being able to see the straps, but in a way I can take it out easily if needs be.

Cheers,
Steve.


[This message has been edited by stevencotton (edited 28 August 2001).]

David_Wallis

I would have said that a 160.2 bridged is too much for a 10" sub... however ported boxes do need more power? (to achieve same as sealed... I think, correct me if wrong)

Has the 160.2 got seperate bass and treble controls on the amp like mine do...

Try turning the gain down a bit..

David

Richiehash

what is your crossover point for the sub?
i'd use about 80hz or less.
if that doesn't work an old trick is to damp the port slightly with a bit of foam or summat similar
richie

kryten

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by stevencotton:
<B>The fronts do need upgrading, still running those 4" Infinitys, is possible the HU I ran them off clipped prior to me amping them. Infinity sub is in a pretty normal looking ported (at the top unfortunately) box. [/quote]

OK, so your fronts are producing nothing below say 150Hz (probably nearer 200Hz) and your sub shouldn't be doing much about 80Hz so you have an octave gap - no wonder it doesn't sound right!

Also a 'normal looking' box is no use - what is the internal volume, what are the length and diameter of the port: are these correct for the sub?!

The biggest problem with any sub is usually its in the wrong box!

stevencotton

"say 150Hz probably nearer 200Hz"?

That sounds accurate Kryten! Where on *earth* are you getting those figures from?

David, there aren't any bass/treble controls on my 160.2, just gain and a hi/full/low pass filter.

I haven't had any time to take a longer look at it yet, but should I find anything out I'll let you know.

Steve.

john banks

Kryten knows his onions and speakers. Accurate enough to say that you have up to one octave with very poor freqeucy response. And Rockin'Ru will tell me I have another octave below 40Hz which I'm not hearing and he's probably right! Low frequency response from 6.5" speakers starts to tail off from 80Hz usually, 5" speakers is typically about 120Hz, 4" from 150Hz. Rough guides I have in mind from looking at FAQs and specs. You need bigger cones to go lower. And speaker manufacturers claim silly figures for low end freq response - ie. 27Hz for many 6x9 - but if you look at what they are taking as a cutoff it is many dB below the shoulder. For your purposes you want a flatish freq response down as far as the "cut" off which is actually a roll off. So the shoulder of your curve will be steep at 80Hz from the natural roll off of the driver and the high pass filter - which ideally would be 18dB for a sealed sub if you belive the theory. If you run the sub higher than 80Hz it will sound crap and you will be able to localise its source which sounds nasty. You need speakers that go down to 80Hz - ie. 6-6.5".

john banks

It double posted after a delay - sorry.

[This message has been edited by john banks (edited 29 August 2001).]

stevencotton

Yeah I definitely need to upgrade those fronts, they're next on my list. I'm running the subs amp on its low pass filter, big difference noticed on hi and full as far as the sound is concerned. It would seem I'll never fill the gap unless I get larger front speakers, perhaps then I won't notice a problem.

Steve.

kryten

Steve, you're right in that those figures were guesses, but they're based on past experience. I honestly doubt you're getting much useful output below 150hz from them.

The problem is that any hole in the frequency response will play havoc with the rest of the frequencies, which may be why the sub sounds so boomy. Also as there are no other 'bass' sounds, this will emphasise any booming to your ears and will make it easy to localise the position of the sub.

However, the sub box is still a possibility and I have heard a couple of good installs that used 4" speakers plus a sub (though they also had a pair 31band EQs!).

If the sub box is the problem, you may find it helps to stuff the port completely full of whatever you can cram in there. A foam/rubber bung the right size is best, but a load of rolled up socks usually work just as well!!

Ported boxes can sound quite boomy when fired into corners so moving it about is a good idea.

Also, phasing of subs can be wierd. It often pays to connect them out of phase and the same can also be done to good effect with one of the front speakers, which again may help - you don't know until you try

Welcome to world of tweaking and subjective decisions!!

stevencotton

Discovering how much of a pain in the 4rse it is to get a decent sounding system in a car now. The 4's in my old Novavan with an 8" RF sealed sub sounded pretty good in the small cabin but once I put this new sub way back in the boot it's totally changed the harmonics. I played with the phasing of the fronts when I put them in initially and they're sounding as good as I can get - although I'll have to check again if I swap the subs phase, fortunately I can do that without taking the panels off. I really can tell you the location of the sub down to the nearest centimetre at the moment, can't wait to get some larger fronts. Then I can start getting rid of all the rattles, excess joy!

Cheers guys,
Steve.