Subs - Educate me please...

I realise this might be like trying to educate pork, however, I have recently borrowed a sub from a friend with a view to buying.

I have replaced the original rear speakers with some 6x9s but I was not getting the depth of base that the old ones were giving. I tried amping the 6x9s but still not getting quite what I was hoping for.

So I have borrowed a 10" decent (JBL) sub in a sealed box. Lab test tonight in the garage (cant go out in the car as... well, its broke, you have all been there right? ) and the results were great on the old rock stuff, but as soon as any modern dancey stuff comes through the base is waaaay to much. This can be sorted by messing with the head units base settings but its a PITA and I can see it being dangerous while driving.

Questions:

Is there a sub/amp setup that will give a consistant underlined base note across all types of music?
What is an active sub?
Would a ported box help?
Would an 8" provide a decent sound?
Can I change anything on the amp/head unit to give a more consistant sound?
Am I asking the right questions/giving you enough info?

Answers:

No, it's all down to recording levels on different albums.But a good installer may be able to tune your system to a happy medium.
An active sub is a sub box with a built in amp.
No, some subs are designed to use a ported box and others sealed, not much difference between them.(from my limited experience)
An 8" sub would be a tighter punchier bass, not so deep and rumbling.
Not really, see first answer.

You could try and find a separate graphic equaliser thats easier to adjust or a new head unit with more user freindly controls.I have an Alpine which i find very easy to control, i tinker with the levels almost as much as the volume.
A full system with amped component speakers up front will give you a fuller sound and not get drowned out by a sub.
Or just pick a genre and stick to it!

My head unit, although a bit old hat now, is/was pretty good, a Pioneer 6?00 something-or-other 50x4. I find it really easy to adjust as I have had it long enough to know my way around it blind folded. I just dont fancy having to adjust it for every track.

The guy who I have borrowed the sub off, is good with this sort of thing so when he is back from holiday I will get him to take a look and try and balance the sound.

Maybe component speakers are the way forward, either that or start listening to folk music!

Is the coop just not inherently good when it comes to acoustics? My limited knowledge would have rated good 6x9s higher when it comes to offering bass and quality over the standard speaker but this was far from the case.

You just need a remote gain switch for the sub. You mount it in easy reach of the dash and then you can turn it up and down.

As a first stop try turning the amp gain down. You're probably getting a non linear response which is causing that booming on dance type music.

I had a play with the settings on the amp yesterday and I have got a much better set up now, not perfect, but much more manageable from the headunit. I will look into the remote gain switch though, thanks for the suggestion.

My recommendation - get one of these http://www.caraudiodiscount.com/subwoofe...re-p-17329.html

Put it either in the rear drivers side passenger footwell or in the cubby hole in the boot.

I have one. It will not sure some of the boooooom connoisseurs who populate this section of the forum, but if you are a normal person it will give you the depth of sound you are looking for at minimal cost and at minimal size.

I have mine in the rear footwell. People can still sit there with their feet either side over short journeys. For longer ones it takes me maybe 2 mins to remove it and put it in the boot.

I would and "will" go with a remote gain dial in the cabin and will also use a Pre amp (I have a tichi pheonix gold pre amp booster) where you can also modify as the touch of a dial, althoughh safer is the gain dial.

oh oh forgot to ask are you going to Dynamat - This will also make substantial diff. to the overall output of diff. pieces of kit.

Check your head unit isn't running wiht loudness turned on or any other graphic functions. I would tune the bass via the amp gain, and try reversing the sub woofer phase, playing with the cross over point or roll off is useful as you might have constructive addition of the bass notes from head unit and sub if sub and shelf speakers are both playing the same range with out roll off. Can you set the head unit output or the 6x9 amp to high pass, and match the sub woofers low pass frequency (you head unit might have this control for pre out built in otherwise most amps have LP and HP filters).

rich I think I will be pinging you in the future chap, Once I get moved into the "new" house and decide to strip the coupe down for some sound additions, gonna make my little boy vibrate across the back seats, no Really I'll try (him with his little F1 ear protection on)

I'll have to utube the momment he hears propper base in the coupe i Think I'll probable LMFAO.

R00

Look after his ears R00 I'm deaf as a post now, far too many nights at Frantic!!

There's a massive difference in the sound of sealed and ported boxes.

The subwoofer in a sealed box can handle a lot more power than that of a ported box, however, ported boxes are MUCH louder than sealed boxes.

For music like rock/pop, I'd be inclined to use a sealed box as you get a better all round bass right through the low end frequency spectrum.

If you like electronic music like house/trance etc, a ported box is better for a hard punch.

Thanks for the suggestions, I will take a look at the loudness setting etc tomorrow, I usually have it turned on. TBH I was thinking about putting the original speakers back in and giving them a whirl with the sub as I am not having much look with setting it up. Only just got the car back though but I want some decent sound in there for an up coming road trip on Sunday.

Looking at a temperary fix for now as I havent got time to sound deaden or go and buy/install a remote gain, but I will look at these when I get back.

You only need to turn the gain up/down on the sub amp after you have got the speakers sounding good on the headunit. That'll give you a good start till you have chance to play around. Turn the gain right down on the sub amp and then add a bit at a time till it sounds good.

Biggenz is right about ported boxes, ported ones really put out the bass, sealed are much tamer needing high input for high SPL.

It is. But there's more to it than that. A ported box will be louder for a given frequency (the tuned length it the port).

As for power handling, it depends on your kit. Some subs are made to operate in free air.

What you want is a bandpass enclosure to get the best of both with that sweet spot where the rest of your system is lacking.

I personally find sealed boxes good all rounders. Not too keen on ported. But I have heard some good ones that do well on dubstep and slower moving baseline music

i remember looking into audio stuff years ago, the vas and qtc values etc.

the biggest factor when selecting a sub, aside from power handling and driver size (as these will dictate the type of install you will achieve) is the sensitivity.

A speaker with +3bd sensitivity will give twice the output in efficiency terms.

Less losses occur and therefore less input is required to move those coils.

Its not (all) about watts, or rms watts imo, its about driver sensitivity.

Therefore whenever possible

If I understand your set up correctly, you have a head unit running your 6x9s and then a sub with a separate amp. With this set up you will struggle to get what your looking for. My general advice is you need a amp to drive both the vocals and then then also the sub.Coupled with moving to a set of components fitted somewhere in the front of the car. With a dedicated amp you can then set the gains correctly with a multimeter and generally get a pretty good start point for crossover points between the sounstages. As for subs my view is sealed units all the way as ported units in my view are boomy around the tuned port length parameters. As always with most things in life, quality costs and I personally use JL Audio as for SQ they are very good. Final suggestion would be to stick with a single make of amp/speakers as it will help with getting the best out of the kit in question

Jamie

Sure sensitivity is the main key to SPL per watt, but in the car the resonance will be the main thing controlling the frequency weighting. Ported boxes do have a tuned frequency which is then altered once it end up in another enclosure i.e. the boot. A ported box will create a speaker of higher efficiency then a closed box in any case I have ever seen. Buy without looking for references I would be sure a sealed enclosure would have less variation in its frequency response prior to its natural roll off frequency then its ported or band pass versions.

Anyway I would go with what Jamie says which is what I used to have. Head unit with 3 pre outs to a 4ch +1ch amp. The 4ch would power only front components minus the passive crossovers using the High pass and Low pass outputs from the head unit (need a fairly well specced HU), then the SW out put for the single channel amp. I would set all amp gains at 0db and any bass boost functions to off. Run the head unit with on eq modification or loudness. Adjust the High low pass frequecncies and roll off per octave until you get a fairly balance sound. if one of the ranges eith High, mid or low is seriously lacking up its level via the HU or the amp gain. Fine tune via the Equaliser set up. Some head units allow more then one custom eq setting thus you could have different profiles for different music if you were so inclined.

Really good HU's can use a microphone to set up the unit automtically including time delay for the offset drving position.