Please help me set up my system

[solrighal 10+ year member]

Hi folks. I've googled and I've searched this forum but I'm still looking for a definitive guide to setting up my gear. I just need to know the basics as I'm scared I'm not getting the full potential. Equipment is as follows...

Alpine CDE-102Ri head unit (two 2V pre-outs)

Alpine MRX-F65 four-channel amplifier

Alpine SPG-17CS Type-G front components

Stock rear components

Alpine SPG-1244BR subwoofer

The rears are connected to the head unit but are currently faded to zero.

The amp powers the front speakers via channels 1 & 2 and the sub, bridged via channels 3 & 4.

I think I have the gains set correctly.

I have the filter switch for channels 1 & 2 set to HP (high pass) and the crossover set to 80Hz.

On channels 3 & 4 I have the filter switch set to LP (low pass) and the crossover set to 80Hz.

I have Bass Boost EQ on the amp set to zero.

I'm doing all this by ear as I don't have a DMM or an oscilloscope.

Does this sound right so far?

If it is I need help with the head unit. At the moment I have the HPF filter on the head unit set to OFF. Is this right or should I be setting it to the same level as I have on the mechanical switch on the amp, i.e. 80Hz? Or am I maybe being too precise in using 80Hz all-round? Maybe there should be some overlap here or there?

Sorry for all the questions on my first post (other than my posts in the intro section). I look forward to any & all input you folks can supply.

Gordon.

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[sam_b03 10+ year member]

From what I have read on the forum the amp crossovers are more accurate than the HU. once you have the gains set. You can experiment with the Xovers. See what sounds good to ya. you may get more noticible bass from your sub at a high point like 125 or even 200. Check the frequencies of the sub to see how high you can go. For convience you may want to use the HU Xovers so you can hear the difference from the driver's seat. You can always dial it in on amp once you find out what the speakers like.

If you have a subsonic filter, You can cut out the super low end that the speaker can't play anyway. See what it sounds like set at 30.

 

[solrighal 10+ year member]

From what I have read on the forum the amp crossovers are more accurate than the HU. once you have the gains set. You can experiment with the Xovers. See what sounds good to ya. you may get more noticible bass from your sub at a high point like 125 or even 200. Check the frequencies of the sub to see how high you can go. For convience you may want to use the HU Xovers so you can hear the difference from the driver's seat. You can always dial it in on amp once you find out what the speakers like.
If you have a subsonic filter, You can cut out the super low end that the speaker can't play anyway. See what it sounds like set at 30.

Wow, that was quick. Thanks very much. If I set the amp filter for the fronts to HP and 80Hz will it make any difference what I do on the head unit? Is it even wise to use both? I can't get my head around this, lol. I see what you're saying re crossovers though. I'll try the amp crossover for the fronts set to 100Hz and the sub set to 60Hz and see where I'm at.

Gordon.

 

[solrighal 10+ year member]

Well that doesn't work. Doing this by ear is not easy. Can't even decide what music to use as a reference either. I do have an album of test tones though so maybe getting a DMM might be worth it. Or else I'll maybe take the car to a shop for setup. This is all before I even start with the settings on the Head Unit, lol.

Here's the stats for my speakers -

Alpine SPG-17CS

Frequency Response: 68Hz to 20kHz

Impedance: 4Ohms

Sensitivity: 88.5dB/W (1m)

Alpine SBG-1244BR

Frequency Response: 28Hz to 1kHz

Sensitivity: 89.8dB/W (1m)

Gordon.

 

[J31Rob 5,000+ posts]

From what I have read on the forum the amp crossovers are more accurate than the HU. once you have the gains set. You can experiment with the Xovers. See what sounds good to ya. you may get more noticible bass from your sub at a high point like 125 or even 200. Check the frequencies of the sub to see how high you can go. For convience you may want to use the HU Xovers so you can hear the difference from the driver's seat. You can always dial it in on amp once you find out what the speakers like.
If you have a subsonic filter, You can cut out the super low end that the speaker can't play anyway. See what it sounds like set at 30.

a.) That's dumb and not true at all.

b.) Also dumb. Your crossover points determine the speakers ability to take power.

c.) Playing high frequencies like that is going to drastically increase the temperature of the speakers voice coil. That is what your midrange should be playing, not your woofer.

 

[solrighal 10+ year member]

So what's the right way to go if this advice is wrong? I find a lot of conflicting advice to be honest and its very difficult to work out what's good and what's bad.

 

[itsblown 10+ year member]

So what's the right way to go if this advice is wrong? I find a lot of conflicting advice to be honest and its very difficult to work out what's good and what's bad.

Everything you listed above was correct, what more are you looking to get out your sound system that you aren't getting now? The only thing I would suggest would be to properly set your gains and give your woofer some more power.

 

[solrighal 10+ year member]

Thanks very much mate. Just to confirm - you say setting the front crossover to around 100Hz and the sub to around 60Hz should work fine?

My problem is that I have no terms of reference; this is the first and only "proper" car stereo I've ever really heard. Perhaps I'm getting everything I can out of it and then again maybe there's something I'm missing. Also, I'm 47 and my hearing almost certainly isn't as good as it once was. That's probably a good enough reason to get it done professionally. When I set my gains I followed the advice to turn them all to zero, turn the HU volume to 3/4 and then increase the gains until distortion sets in, then back them off a tad. Well distortion never really does set in. At least not audibly and not at a volume I'm ever likely to use. Another argument for getting it done professionally I guess.

Thanks for all the help guys. I'll keep this thread updated if there are any developments.

Gordon.

 

[Fi-brations 10+ year member]

the subwoofer is fine set at 80hz, xover slopes do have a role off, but where the subwoofer slopes off the midbass should pick up, so setting them both at 80hz is fine, you'll just have to play around with what sounds best, but ur subwoofer lpf should not be set above 80hz and your midbass lpf should not be set below 80hz unless you know what you are doing and what your midbass drivers can actually handle in terms of low frequency reproduction. So far you have done everything right, as far a using the amp vs hu's xovers, just use the one that has the most flexibility. Your supposedly sending your subwoofer 300w right? That sounds like a good wattage for that sub, but if you want you could try sending it a little more, but if more bass is your goal you should upgrade both your subwoofer and put in an amp for it. If you just want higher clarity from your speakers, I would suggest upgrading the hu, speakers, speaker amp; you dont have to do that all at once, one step at a time should yield noticeable increases in sq

 

[Flipx99 5,000+ posts]

I would use HU crossovers vs amp crossovers any day of the week and twice on Sunday.

Experiement for yourself...you can hear the difference.

 

[solrighal 10+ year member]

It would certainly be easier to "tune" the sound if I used the HU crossovers but if I go that route what do I set the amp crossovers to? Or doesn't it matter? Sorry for all the questions.

 

[Flipx99 5,000+ posts]

Does your amp allow you to turn them off?

 

[Fi-brations 10+ year member]

It would certainly be easier to "tune" the sound if I used the HU crossovers but if I go that route what do I set the amp crossovers to? Or doesn't it matter? Sorry for all the questions.

set whichever one you dont use to flat, off, or bypass whatever your equipment uses to say it

 

[solrighal 10+ year member]

Does your amp allow you to turn them off?

Next to each crossover rotary control there is a 3-position switch - OFF/HPF/LPF.

I assume I should be setting these switches to off then?

My HU allows me to set the "bass centre frequency" with choices ranging from 60Hz to 200Hz. I'm guessing this should be set to 60Hz?

The HU also allows me to adjust the "bass bandwidth", with settings ranging from 1 to 4. No idea what to do with this. Is this where people talk about "blending"?

For treble my HU allows me to adjust the "treble centre frequency" in steps between 10kHz and 17.5kHz. I have no idea where this should be set.

Finally, the HU gives me the option of an "LPF" with available options of OFF/60Hz/80Hz/100Hz. Again, clueless.

 

[Fi-brations 10+ year member]

then just turn them off and use your hu's xover