Just trying to work out a minor issue with my HU. it's a Alpine CDA3815.
I have just installed a second amp to run my JL 12" sub. It's a Alpine MRP-M450.
I connected it from the outputs of the 4 channel amp, a Alpine MRV-F340.
It sounds sweet and for a moment my mission seemed to be coming together fine.
The problem is that the HU has Sub-W output level control, which I consider to be quite a handy addition.
But, it doesn't alter the output at all.
Does anyone know if there's something in the setup which I might have missed?
????
Gene
Replies (20)
kirchatndftbl on 08/5/2007 21:06:42
the rca ouput from the HU could make a difference does this HU have more then one rca pre-out?????
vtcommodore on 08/5/2007 21:13:51
Sorry, unfortunately the initial installation of the HU was done by a Pro installer. I do recall though, at the time, that he asked me if I was going to add a Sub. I thought at the time that I'd be happy with it as is... fatal last words. So, perhaps there's someting done with the install then that has disabled this function.
Doh.
vtcommodore on 08/5/2007 21:20:43
Ok, just checked... it has sets of preouts... does this mean that I'll have to run another set of rca's from the HU to use this feature?
vtcommodore on 08/5/2007 21:21:50
that was meant to read "Three sets of preouts", dodgy typing
Gene
vtcommodore on 08/5/2007 21:42:44
I think you've pretty much answered my question. Obviously the third rca is necessary to run direct to the sub amp.
Cheers
swez on 08/5/2007 21:55:20
Yes, the Sub outputs must be used to enable the Sub output menu feature. Hand the man another pair of RCA cables please so he can get this part done and out of the way... ;-) No biggie we hope.
Swez
kirchatndftbl on 08/5/2007 22:44:03
thats what i was thinkin the problem was using a different pre-out should fix it
trunkisloud on 08/5/2007 23:22:18
so we are clear that he is not to just switch the rca's from the regular channels to the sub?? if that is done then the 4 channel would see nothing but low freq. .....as swez said ..another set of cables is in order...
p.s. i scored that same alpine 450 for 60 bucks.....and it has some nice power...im running 2 premier dvc's off it and it does excellent....
vtcommodore on 08/5/2007 23:58:37
yeah, all clear.. it means a lot of work to run another rca... but, I do like the idea of having the adjustment on the HU..
Great price for the 450 mate!
I paid $300AUD for mine.
I get the feeling you guys in the states have it pretty sweet with price/quality of gear available a lot better than your antipodean friends.
Hey Trunk' with the 450, what's the go with bass eq setting etc. what's the best way to "tune" the amp properly?
I'm pretty impressed with it as is, but, almost guarantee there's more I could do to it.
trunkisloud on 08/6/2007 00:08:50
well if youre having problems with wrong frequencies coming through the sub it could be because you are linking the sub amp to the 4 channel amp....once you run it to the sub output on the hu then it will be cleared up.. ..assuming you have an adjustment on your deck that can adjust what frequency (40hz ,80hz , 120hz ect) you can sent to the sub, then you want to have it as high as you can so as not have too steep of a slope in your range..,..when you use the hu crossover with the sub crossover it's too much....i found that out after a few days of messing with this amp....once its set right..this amp is pretty dang accurate....as far as the price i paid for the amp...i got it on ebay as i get a lot of things there....bargain shopping.
vtcommodore on 08/6/2007 00:12:42
So I should allow full range from the HU and just eliminate higher freq's with the amp x-over?
Is that what you mean?
vtcommodore on 08/6/2007 00:14:01
I was just wondering what the bass eq knob is intended for? the amp has the gain control, x-over level and also the bass eq...
what will that be for?
trunkisloud on 08/6/2007 00:22:38
yea allow all freq's and let the amp sort them out....i dont really use the bass knob on the amp...i mean i turned it a little just to get the desired sound but its not something you wanna crank on......what model jl 12 is that ...w something ....which one is it./??i have my lp filter set around 80ish ...its hittin nicely..so what type of box are you using.......and is the sub a dvc 2ohm ?? 4ohm??
vtcommodore on 08/6/2007 00:35:29
sub is a jl12w3v2 4ohm dvc. I made a sealed enclosure to JL specs. set the gain only to nom. and the x-over at 60. goes pretty hard even with the gain wound back so much. just wanted to take it easy until I know what I'm doing with the settings.
It does have plenty of punch though!
trunkisloud on 08/6/2007 00:37:27
do you have the sub runnin at 2ohms??
vtcommodore on 08/6/2007 00:44:18
Yeah, well, the amp is claimed to output 400wrms@2ohms 14.4v. so I didn't want to crank it right up as the sub is 300wrms. It seems like a good pairing.
You scored a bargain at $60
swez on 08/6/2007 00:59:40
The Bass EQ is a bass boost of 0 to +12dB bass boost at 50 Hz. In most well tuned systems, not really needed.
If you have an AC voltage meter and using a 2 ohm load, (Speaker coils in parallel) the voltage at full power will be 28 volts AC. That's 400 watts @ 2 ohms. If you are well under that voltage at bass peaks, there's amping power left and waiting to be used, if you wish. If you wish to stay at ~ 300 Wrms, your voltage reading will be 24.5 VAC.
Depending on the speakers you have now, you may want to bump the LPF to about 80 Hz on the M450. 60 Hz is fine if the full range speakers are able to take power at 60 Hz. That's usually 6.5" rounds and 6x9" ovals.
However, if you have smaller speakers then mentioned, (5.25" or smaller) 80-100 Hz is often better for them and adjust the sub LPF to match the full range HPF settings.
Got all that?
Swez
vtcommodore on 08/6/2007 01:10:07
Yeah I've got 6.5" components (only Sony, wish I'd seen this site before I went shopping for those) in the front and some Alpine 6x9's in the rear.
I might try it at 80Hz and see how it sounds.
Swez, how would I best find the appropriate gain setting without the voltmeter you mention?
I have read that you turn the volume up to 3/4 then increase the gain until it distorts and back off a fraction.. only problem being, the sub is in the boot with the amp and therefore will render me deaf by the time I carry out this adjustment.
??
swez on 08/6/2007 01:57:24
Gene,
We can do a reasonably good job of tuning and tweaking by ear, but there are limits. (Human hearing is not on par with proper test equipment)
Yes, we can do a pretty good cursory job by ear as you say...
1. HU at 75-80% max volume
2. Tone/EQ controls set to "flat" (No boost, no cuts)
3. Adjust gain on each amp until audible distortion is noted and then back off until it sounds clean and crisp
4. Do the Mid/Highs amp first, then add bass until we get good balance and all is clean, crisp and natural sounding
5. Set HPF on amp based on Mid/High speakers used (80 Hz is good)
6. Set LPF on sub amp to match HPF settings on Mid/Highs amp (80 Hz.)
To get a real sense of what's going on, we do these adjustments outside the vehicle. (Sub amp off pls.) Open the doors and stand behind your car to adjust Mids/Highs about 10 meters behind the car. Listen for clean and clear Mids and Highs. If we hear shrill highs and muddy Mids, the amp is probably clipping or speakers are overloading. (A HU remote control is most helpful here)
Once you get the front stage set well, adjust the rear stage to fill, but not dominate. (Rear stage speakers in the rear deck are often more efficient) We want the front speakers to dominate and the rear speakers to compliment what's going on in the front stage. We can do this inside the car, but at lower volume.
Lastly, we add the bass engine. We want enough bass to fill in the lower octave, but not so much bass to be overpowering. (preference to the user's taste) Here, we listen for clarity and punch of the bass engine. We look for good bump, but not to a point where all we hear is bass. (Yes, some like it bass heavy, but that gets old fast)
Those are the basics. Use music that really tests the system well. A music source we know very well and has distinct male & female vocals, good bass thump and perhaps some intersting percussion, acoustic piano, synth and maybe some brass horns. It really depends on the individule taste in music... basically, use music material we are very familiar with as we set up the system.
If we get that part right, most other music will fall into place very well.
Make sense to ya?
Swez (Dave)
PS 2:00 AM and now time for some snooze... good night Gene! ZZZzzzz
jamesp on 08/6/2007 07:37:44
Invest in a $20.00 Volt meter and a set of ear hearing protection type ear muffs when you get a chance...The meter will come in handy for a lot of things.
I have just installed a second amp to run my JL 12" sub. It's a Alpine MRP-M450.
I connected it from the outputs of the 4 channel amp, a Alpine MRV-F340.
It sounds sweet and for a moment my mission seemed to be coming together fine.
The problem is that the HU has Sub-W output level control, which I consider to be quite a handy addition.
But, it doesn't alter the output at all.
Does anyone know if there's something in the setup which I might have missed?
????
Gene
Replies (20)
kirchatndftbl on 08/5/2007 21:06:42
the rca ouput from the HU could make a difference does this HU have more then one rca pre-out?????
vtcommodore on 08/5/2007 21:13:51
Sorry, unfortunately the initial installation of the HU was done by a Pro installer. I do recall though, at the time, that he asked me if I was going to add a Sub. I thought at the time that I'd be happy with it as is... fatal last words. So, perhaps there's someting done with the install then that has disabled this function.
Doh.
vtcommodore on 08/5/2007 21:20:43
Ok, just checked... it has sets of preouts... does this mean that I'll have to run another set of rca's from the HU to use this feature?
vtcommodore on 08/5/2007 21:21:50
that was meant to read "Three sets of preouts", dodgy typing
Gene
vtcommodore on 08/5/2007 21:42:44
I think you've pretty much answered my question. Obviously the third rca is necessary to run direct to the sub amp.
Cheers
swez on 08/5/2007 21:55:20
Yes, the Sub outputs must be used to enable the Sub output menu feature. Hand the man another pair of RCA cables please so he can get this part done and out of the way... ;-) No biggie we hope.
Swez
kirchatndftbl on 08/5/2007 22:44:03
thats what i was thinkin the problem was using a different pre-out should fix it
trunkisloud on 08/5/2007 23:22:18
so we are clear that he is not to just switch the rca's from the regular channels to the sub?? if that is done then the 4 channel would see nothing but low freq. .....as swez said ..another set of cables is in order...
p.s. i scored that same alpine 450 for 60 bucks.....and it has some nice power...im running 2 premier dvc's off it and it does excellent....
vtcommodore on 08/5/2007 23:58:37
yeah, all clear.. it means a lot of work to run another rca... but, I do like the idea of having the adjustment on the HU..
Great price for the 450 mate!
I paid $300AUD for mine.
I get the feeling you guys in the states have it pretty sweet with price/quality of gear available a lot better than your antipodean friends.
Hey Trunk' with the 450, what's the go with bass eq setting etc. what's the best way to "tune" the amp properly?
I'm pretty impressed with it as is, but, almost guarantee there's more I could do to it.
trunkisloud on 08/6/2007 00:08:50
well if youre having problems with wrong frequencies coming through the sub it could be because you are linking the sub amp to the 4 channel amp....once you run it to the sub output on the hu then it will be cleared up.. ..assuming you have an adjustment on your deck that can adjust what frequency (40hz ,80hz , 120hz ect) you can sent to the sub, then you want to have it as high as you can so as not have too steep of a slope in your range..,..when you use the hu crossover with the sub crossover it's too much....i found that out after a few days of messing with this amp....once its set right..this amp is pretty dang accurate....as far as the price i paid for the amp...i got it on ebay as i get a lot of things there....bargain shopping.
vtcommodore on 08/6/2007 00:12:42
So I should allow full range from the HU and just eliminate higher freq's with the amp x-over?
Is that what you mean?
vtcommodore on 08/6/2007 00:14:01
I was just wondering what the bass eq knob is intended for? the amp has the gain control, x-over level and also the bass eq...
what will that be for?
trunkisloud on 08/6/2007 00:22:38
yea allow all freq's and let the amp sort them out....i dont really use the bass knob on the amp...i mean i turned it a little just to get the desired sound but its not something you wanna crank on......what model jl 12 is that ...w something ....which one is it./??i have my lp filter set around 80ish ...its hittin nicely..so what type of box are you using.......and is the sub a dvc 2ohm ?? 4ohm??
vtcommodore on 08/6/2007 00:35:29
sub is a jl12w3v2 4ohm dvc. I made a sealed enclosure to JL specs. set the gain only to nom. and the x-over at 60. goes pretty hard even with the gain wound back so much. just wanted to take it easy until I know what I'm doing with the settings.
It does have plenty of punch though!
trunkisloud on 08/6/2007 00:37:27
do you have the sub runnin at 2ohms??
vtcommodore on 08/6/2007 00:44:18
Yeah, well, the amp is claimed to output 400wrms@2ohms 14.4v. so I didn't want to crank it right up as the sub is 300wrms. It seems like a good pairing.
You scored a bargain at $60
swez on 08/6/2007 00:59:40
The Bass EQ is a bass boost of 0 to +12dB bass boost at 50 Hz. In most well tuned systems, not really needed.
If you have an AC voltage meter and using a 2 ohm load, (Speaker coils in parallel) the voltage at full power will be 28 volts AC. That's 400 watts @ 2 ohms. If you are well under that voltage at bass peaks, there's amping power left and waiting to be used, if you wish. If you wish to stay at ~ 300 Wrms, your voltage reading will be 24.5 VAC.
Depending on the speakers you have now, you may want to bump the LPF to about 80 Hz on the M450. 60 Hz is fine if the full range speakers are able to take power at 60 Hz. That's usually 6.5" rounds and 6x9" ovals.
However, if you have smaller speakers then mentioned, (5.25" or smaller) 80-100 Hz is often better for them and adjust the sub LPF to match the full range HPF settings.
Got all that?
Swez
vtcommodore on 08/6/2007 01:10:07
Yeah I've got 6.5" components (only Sony, wish I'd seen this site before I went shopping for those) in the front and some Alpine 6x9's in the rear.
I might try it at 80Hz and see how it sounds.
Swez, how would I best find the appropriate gain setting without the voltmeter you mention?
I have read that you turn the volume up to 3/4 then increase the gain until it distorts and back off a fraction.. only problem being, the sub is in the boot with the amp and therefore will render me deaf by the time I carry out this adjustment.
??
swez on 08/6/2007 01:57:24
Gene,
We can do a reasonably good job of tuning and tweaking by ear, but there are limits. (Human hearing is not on par with proper test equipment)
Yes, we can do a pretty good cursory job by ear as you say...
1. HU at 75-80% max volume
2. Tone/EQ controls set to "flat" (No boost, no cuts)
3. Adjust gain on each amp until audible distortion is noted and then back off until it sounds clean and crisp
4. Do the Mid/Highs amp first, then add bass until we get good balance and all is clean, crisp and natural sounding
5. Set HPF on amp based on Mid/High speakers used (80 Hz is good)
6. Set LPF on sub amp to match HPF settings on Mid/Highs amp (80 Hz.)
To get a real sense of what's going on, we do these adjustments outside the vehicle. (Sub amp off pls.) Open the doors and stand behind your car to adjust Mids/Highs about 10 meters behind the car. Listen for clean and clear Mids and Highs. If we hear shrill highs and muddy Mids, the amp is probably clipping or speakers are overloading. (A HU remote control is most helpful here)
Once you get the front stage set well, adjust the rear stage to fill, but not dominate. (Rear stage speakers in the rear deck are often more efficient) We want the front speakers to dominate and the rear speakers to compliment what's going on in the front stage. We can do this inside the car, but at lower volume.
Lastly, we add the bass engine. We want enough bass to fill in the lower octave, but not so much bass to be overpowering. (preference to the user's taste) Here, we listen for clarity and punch of the bass engine. We look for good bump, but not to a point where all we hear is bass. (Yes, some like it bass heavy, but that gets old fast)
Those are the basics. Use music that really tests the system well. A music source we know very well and has distinct male & female vocals, good bass thump and perhaps some intersting percussion, acoustic piano, synth and maybe some brass horns. It really depends on the individule taste in music... basically, use music material we are very familiar with as we set up the system.
If we get that part right, most other music will fall into place very well.
Make sense to ya?
Swez (Dave)
PS 2:00 AM and now time for some snooze... good night Gene! ZZZzzzz
jamesp on 08/6/2007 07:37:44
Invest in a $20.00 Volt meter and a set of ear hearing protection type ear muffs when you get a chance...The meter will come in handy for a lot of things.
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