Sub & Amp set-up

[fingers]

I can appreciate that this may not be possible to answer as you can't hear how it sounds, but based on theory/ experience etc.... Can you recommend how I should set up my amp? I keep changing it almost every day, but it is difficult to get right. There are 3 dials:
1. Gain Min to max. With 'normal' 1/2 way round and '0.5V' 2/3rd the way round
2. 0 to 12db
3. 50 to 200Hz

I would like the bass to be very deep, and not overpower the treble, but still clear. How do you have yours set? Would a different size/ shape box be better?

I have an:
Alpine MRP-M350 mono power amplifier, 350W RMS - 700w peak. Driving a Kicker Solo-Baric S12L5 600W RMS - 1200W peak in a sealed 1cu/ft box. The Sub is set up to the 2ohm configuration & the Amp is capable of working into a 2ohm load.

 

[Nigel Goodwin]

Is this in-car? - I've never heard decent bass in a car yet, the general theory is that there's not enough room to get good bass in a car?.

 

[mister_e]

if you have a decent results with any SoloBaric Speaker, you should use something else than Alpine... Kicker do some awesome amplifier. Alpine was good in the old days... get worst when they release the V12 model and latest.

Solo Barric will work as you want in a Bass reflex box. Look their specs on the Kicker website.

 

[Sig239]

Hello Fingers
With a little more info I can help you. First you should adjust your whole system together for best results, as you are trying to compliment the rest of the system. Please tell me about the rest of your system. For example: Are you using multiple amps and crossovers? Are you using factory speakers in the other locations? Head Unit? Full range speakers or component speakers? Also, is imaging important to you, or just volume.

 

[fingers]

Yes it is in the boot of my car.
Its a factory fitted 10 speaker system (three in each front door & two in both back doors) plus the subwoofer . I've got a VW Golf with the original head unit - its an oversized one like in Ford cars - I believe it is made by Blaupunkt. There weren't any outputs for the Sub, however I spliced some wires off of the ones coming out of the headunit (L+R from both rear speakers), and fed them into the Amp, which has 4 speaker level inputs. I'm after getting the imaging right, less interested in volume.

 

[audioguru]

A sealed box only 1 cu ft won't give deep lows with that subwoofer speaker. Its size is close to the minimum recommended. 2 cu ft is the max recommended and would go lower.

The headunit isn't designed for a sub so maybe it cuts out the deep lows.

 

[Sig239]

Hello fingers
Since bass is more or less omnidirectional to humans, adding a subwoofer to your sound system will not in any way improve imaging. It will only extend the low end frequency response. In regards to low end response, I agree completely with audioguru about the volume of your speaker box. For the best imaging, most of the sound from directional frequencies (read: upper low end, mids, and highs) should be coming from the front speakers, with the rear speakers set for fill. Usually there is some compromise on imaging for the sake of higher volume(in the rear).
1. Set your bass and treble settings on the head unit to the middle setting.
2. Turn any bass boost settings on your amp to the OFF position.
3. Start out with the amp gain to the lowest setting.
4. Start out with your crossover set to 100Hz.
5. Set your balance and fade to whatever you had it on before, presumably in the center (this might be different if you had a sub pre-out or more amps hooked up)
6. Turn the volume up as loud as you will ever listen to it or until it distorts, which ever comes first. If it distorts first, then back off the volume a little until it does not distort. Distortion is very bad for everything.
7. Adjust the gain on the amplifier so the bass just fills in where rest drops off.(At this point you may have a dead spot if the rest of your system does not go down to around 100Hz-see next point)
8. Adjust the crossover (probably up if anything) until it sounds best. Just remember, louder doesn't mean better. You don't really want to be able to distinguish where the amp and sub come in.

Now, in regards to the bass boost. Is it a remote activated bass boost, or do you have to do it on the amp? This can help extend the low end. It comes in handy when you are on the highway and the road noise drowns out some of your bass. If it is on the amp you can either turn it on at this point, and adjust until you get the sound you want or just leave it off.
I hope this helps you out. Most of what I have learned came from a book called The Car Stereo Cookbook by Mark Rumreich. If you intend on doing any further upgrades I highly recomend reading it.
Edit: I almost forgot. You should Make these adjustments with whatever music you would typically listen to, preferably something with a wide range of sounds. If you find that you must make adjustments, then make small changes to the crossover frequency or the bass boost. Also as speakers "break in" their sound may change a little, so after maybe a month or so (assuming your speakers are brand new) You may have to adjust a little.
Good luck

 

[fingers]

Wow! What a reply! Thanks Sig239 lots of info there.
The head unit setings are very basic ie. Bass, Treble, Balance & Fade. It has got a Gala setting (which in/decreases the volume as the rpm go up/down) that you can adjust the sensitivity of.

Just want to clear up what you mean by the Bass Boost. Do you mean the decibel setting 0-12 or something else? The amp has only got the three dials; gain, db & filter (Hz). Would you tell me where the db should be set to.

Thank you

 

[Sig239]

Hello Fingers
The db setting you refer to is a 50Hz bass boost feature. This can be used to help boost the low end frequency response of your sub and should be adjusted by ear to your preference. However, this is no substitute for a properly sized enclosure. A larger enclosure will extend your bass lower and help the sub to be more efficient.

 

[Sig239]

Well??? How does it sound? Did every thing work out ok?

 

[fingers]

Yes thanks, it has taken a bit of getting used to but does sound better now! I'm considering making the box larger , but at 1cu/ft it takes up almost half the boot space already!!

 

[audioguru]

A round 10" subwoofer can go pretty low in frequency in a 1 cu ft sealed enclosure. A round 12" subwoofer needs a bigger enclosure to reach down to the same low frequency and your square subwoofer's cone area is more than a round 12" one so needs even a bigger enclosure.

I still think that your headunit rolls-off the very low frequencies that cannot be produced by "ordinary" car speakers and that might even damage them.