Finally installing Zapco amp, need sugestions
07-01-2004, 03:51 PM
#1
50 Watt CAFz'r
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Join Date: Sep 2003
Posts: 192
Hey all
I'm finally getting around to finding a home for my AG1000. I want a few suggestions for mounting it.
I don't believe heat will be an issue, I will be running it in 12 ohm mono, measured 368W output this afternoon. I don't have room to mount it between the wall and back of the seats.
Here's my trunk:
Thanks J
[ July 01, 2004, 05:42 PM: Message edited by: Jaxom ]
I'm finally getting around to finding a home for my AG1000. I want a few suggestions for mounting it.
I don't believe heat will be an issue, I will be running it in 12 ohm mono, measured 368W output this afternoon. I don't have room to mount it between the wall and back of the seats.
Here's my trunk:
Thanks J
[ July 01, 2004, 05:42 PM: Message edited by: Jaxom ]
07-01-2004, 09:54 PM
#2
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Posts: n/a
This is more of a comment rather than a suggestion. Why run it at 12 ohm? Isn't that a little bit of a waste of the power that amp can produce?
Anyway, onto your question. I'm thinking pretty mugh right were you have it would be a good place. Make a nice false floor, maybe a fiberglass tub, and carpet/vinyl a trim and your done.
Anyway, onto your question. I'm thinking pretty mugh right were you have it would be a good place. Make a nice false floor, maybe a fiberglass tub, and carpet/vinyl a trim and your done.
07-01-2004, 10:16 PM
#3
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I have been playing with the amp/speakers in vaious config's. With all subs in parallel the damping is greatly reduced, it sounded better with all subs in series. Also when I had the 1.5 ohm load the amp would shut off every once and a while, wasn't hot either.
The subs are basically IB, using the trunk as the airspace. Putting the T/S specs into LEAP? gave ~3.0 cu. ft. box per sub.
I would love to do that, time doesn't permit the carpetting or vinyl. Thanks.
J
The subs are basically IB, using the trunk as the airspace. Putting the T/S specs into LEAP? gave ~3.0 cu. ft. box per sub.
I would love to do that, time doesn't permit the carpetting or vinyl. Thanks.
J
07-02-2004, 12:57 PM
#4
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
Agreed that is a waste of power. If you metered it @ 368 WRMS that means each sub is only getting 123 wrms, that amp can do so much more.
I understand your issue with running the amp @ 1 1/3 ohm, but why do you need to run all three subs? Why not nix one sub and run the amp @ 2 ohm mono? - You can do this by running the set up as a ported IB. When ported speakers need more airspace, potentially pushing the needed air space for each driver up to 4.5 cu feet - thus bringing you back to the 9 cubes you needed with all three. That way each sub will get more power, the amp will be pulling its weight and it will be a tonne louder. Then you also won't be using series wiring. Series sucks for * reasons
(1) The imperfections created by one speaker's coil will be passed electronically to the next speaker. (IE if @ 100hz the coil offers 6 ohms of resistence instead of the rated 4 ohms, that imperfection will further diminish the 100hz signal going to the next speaker - therefore all of the imperfections will be exemplified by each speaker added to the set-up).
(2) If one speaker goes, they all go down with it.
(3) Power - you lose too much of it.
(4) If you don't know who to wire series properly, you get some serious phase issues.
BUT,
you didn't ask for that advice . . .
So I'll say, make an amp rack under the rear deck. And you are right @ 12 ohm mono, heat will not be an issue.
I understand your issue with running the amp @ 1 1/3 ohm, but why do you need to run all three subs? Why not nix one sub and run the amp @ 2 ohm mono? - You can do this by running the set up as a ported IB. When ported speakers need more airspace, potentially pushing the needed air space for each driver up to 4.5 cu feet - thus bringing you back to the 9 cubes you needed with all three. That way each sub will get more power, the amp will be pulling its weight and it will be a tonne louder. Then you also won't be using series wiring. Series sucks for * reasons
(1) The imperfections created by one speaker's coil will be passed electronically to the next speaker. (IE if @ 100hz the coil offers 6 ohms of resistence instead of the rated 4 ohms, that imperfection will further diminish the 100hz signal going to the next speaker - therefore all of the imperfections will be exemplified by each speaker added to the set-up).
(2) If one speaker goes, they all go down with it.
(3) Power - you lose too much of it.
(4) If you don't know who to wire series properly, you get some serious phase issues.
BUT,
you didn't ask for that advice . . .
So I'll say, make an amp rack under the rear deck. And you are right @ 12 ohm mono, heat will not be an issue.
07-02-2004, 02:32 PM
#5
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Hey
I do also feel that the amp is not being used to its full potential, it's what I have laying around. I'm increasing my power to the subs with 123W, they used to be 60W each. From what I was told these have a thermal limit of 200Wrms.
What info is needed to make a ported IB? the 3 cu ft size is for a sealed enclosure, ported was somewhere around 4.9. What is the benefit of using this type of box? The peak impedance per sub was 19 ohms at 47Hz. I haven't had a problem with the phasing, I have been playing with that as well.
I've never had a ported box in any of my vehicles, I prefer the sound from the sealed ones. I was looking last night into installing it on the hat shelf.
Thanks, J
I do also feel that the amp is not being used to its full potential, it's what I have laying around. I'm increasing my power to the subs with 123W, they used to be 60W each. From what I was told these have a thermal limit of 200Wrms.
What info is needed to make a ported IB? the 3 cu ft size is for a sealed enclosure, ported was somewhere around 4.9. What is the benefit of using this type of box? The peak impedance per sub was 19 ohms at 47Hz. I haven't had a problem with the phasing, I have been playing with that as well.
I've never had a ported box in any of my vehicles, I prefer the sound from the sealed ones. I was looking last night into installing it on the hat shelf.
Thanks, J
07-03-2004, 09:25 PM
#6
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Join Date: Jan 2001
Posts: 2,026
Ported vs sealed, the classic debate.
People will tell you that sealed will give you "tighter, more accurate bass" while ported will give you "Louder, but more sloppy bass." This is not 100% true.
A ported box will be louder, allowing the woofer to play lower frequencies with greater ease. As for the accuracy of ported: A PROPERLY built ported box will give you tight and accurate bass. Ported bass gets "sloppy" when it's not tuned properly, or the vents aren't built right causing 'chuffing' air leaking elsewhere etc. But a well built ported box will sound just as tight as a sealed box and will play lower than sealed.
With that being said, It will be VERY difficult for you to make an IB set-up a properly built ported box. There are so many additional factors to consider such as sheet metal flex (Because you are using the trunk as your box walls) properly sealing the trunk (From the cabin AND from the outside world) getting an accurate cubic volume from a trunk and so on.
Yet still, this is how I am running my set up. I have a baffle wall set-up and tuned to 28hz. I love the way it sounds. I first built it true infinite baffle (no ports), and it sounded Okay, but I was missing the low lows. Then I ported it and I got much lower excursion. I suppose I got lucky and that my trunk works well for this set-up. How I did this? Ran my T/S through WinISD, through in my trunk volume and then played with tuning frequencies until I got a graph I liked the look of. A bit red-neck but it worked. Then I treated my trunk like a regular box and made the ports the length recommended.
With all of that being said to answer your quesiton about what would be the benefit of using that kind of a box; the benefits are 2 fold
(1) Further low frequency extension. Your speaker response will remain flater long before roll-off
(2) This would allow you to use 2 speakers instead of 3 - as you mentioned each speaker would need roughly 4.9 cubes totalling to 9.8 which seems to be a number good for your trunk. When you use 2 speakers your power will increase. Even if you still run the speakers in series giving an 8 ohmn final load, I think the amp would probably produce about 450 wrms giving each sub 225wrms (25 watts over the recommended rating will not hurt the speakers) That much more power would be louder than using three subs.
Actually, give it a try without porting it. Wire all 3 together like you have them, listen to it, then take one of the speakers out of the chain and listen to it again at the same volume. Hear what it sounds like.
As for phasing, you probably know what you are doing so that won't be a problem.
To clarify what I said earlier about combining sub imperfections - you said peak impedance is 19 ohms @ 47 hz; when that runs through three of the same coils that impedance will jump to 57 ohms. At 57ohms of resistance that amp would be giving each coil 40 watts at best. But still, this is just my electrical hypothesis, and it might not make a lick fo a difference wether it is series or parallel because that area of high-resistance will be there regardless.
What do you mean "installing it on the hat shelf"?
People will tell you that sealed will give you "tighter, more accurate bass" while ported will give you "Louder, but more sloppy bass." This is not 100% true.
A ported box will be louder, allowing the woofer to play lower frequencies with greater ease. As for the accuracy of ported: A PROPERLY built ported box will give you tight and accurate bass. Ported bass gets "sloppy" when it's not tuned properly, or the vents aren't built right causing 'chuffing' air leaking elsewhere etc. But a well built ported box will sound just as tight as a sealed box and will play lower than sealed.
With that being said, It will be VERY difficult for you to make an IB set-up a properly built ported box. There are so many additional factors to consider such as sheet metal flex (Because you are using the trunk as your box walls) properly sealing the trunk (From the cabin AND from the outside world) getting an accurate cubic volume from a trunk and so on.
Yet still, this is how I am running my set up. I have a baffle wall set-up and tuned to 28hz. I love the way it sounds. I first built it true infinite baffle (no ports), and it sounded Okay, but I was missing the low lows. Then I ported it and I got much lower excursion. I suppose I got lucky and that my trunk works well for this set-up. How I did this? Ran my T/S through WinISD, through in my trunk volume and then played with tuning frequencies until I got a graph I liked the look of. A bit red-neck but it worked. Then I treated my trunk like a regular box and made the ports the length recommended.
With all of that being said to answer your quesiton about what would be the benefit of using that kind of a box; the benefits are 2 fold
(1) Further low frequency extension. Your speaker response will remain flater long before roll-off
(2) This would allow you to use 2 speakers instead of 3 - as you mentioned each speaker would need roughly 4.9 cubes totalling to 9.8 which seems to be a number good for your trunk. When you use 2 speakers your power will increase. Even if you still run the speakers in series giving an 8 ohmn final load, I think the amp would probably produce about 450 wrms giving each sub 225wrms (25 watts over the recommended rating will not hurt the speakers) That much more power would be louder than using three subs.
Actually, give it a try without porting it. Wire all 3 together like you have them, listen to it, then take one of the speakers out of the chain and listen to it again at the same volume. Hear what it sounds like.
As for phasing, you probably know what you are doing so that won't be a problem.
To clarify what I said earlier about combining sub imperfections - you said peak impedance is 19 ohms @ 47 hz; when that runs through three of the same coils that impedance will jump to 57 ohms. At 57ohms of resistance that amp would be giving each coil 40 watts at best. But still, this is just my electrical hypothesis, and it might not make a lick fo a difference wether it is series or parallel because that area of high-resistance will be there regardless.
What do you mean "installing it on the hat shelf"?
07-03-2004, 11:11 PM
#7
50 Watt CAFz'r
Thread Starter
Join Date: Sep 2003
Posts: 192
Hey maltesechicken
I gave what you suggested about loosing one sub and just running the 2 in parallel. The sound level didn't seem to be much different compared to the three in series. It looked quite different on the spectrum analyzer though. The speakers low end roll-off was about 25Hz at a comfortable listening level.
The only problem I ran into was the huge overpowering of the rest of the system, with the Zapco and Alpine XO gains turned all the way down there was still more than there should be by approx 4dB.
When I put the 2 in series I was able to bring the gains back to 0dB position. I measured 423W with my scope. The overall matching seemed better than either the 3 in series or parallel as well as the 2 in parallel.
I'm assuming that leaving the third sub in place will have more of an effect on the frequency/level response since it is acting as a passive radiator? This may be good or bad.
I am doing some experimentation with high Q BP filters and was thinking of insterting one in the signal chain that was matched to the subs impedance response. I figured that having the 3 in series would be a good real world test, I'm not quite sure what the phasing would be like though?
I've been using a 4" thick multi-layered pad for sound deadening, it makes a huge difference on the sound, even if it is just laying in the trunk.
The rear deck of the car, the hat shelf. I think this is an ideal location for the Zapco piece, it is wide and shallow and fits perfectly there. Here's a couple of pic of what my bro and I have been working on. Sorry for the poor pics.
There are more of the full project for anyone interested.
[ July 04, 2004, 12:13 AM: Message edited by: Jaxom ]
I gave what you suggested about loosing one sub and just running the 2 in parallel. The sound level didn't seem to be much different compared to the three in series. It looked quite different on the spectrum analyzer though. The speakers low end roll-off was about 25Hz at a comfortable listening level.
The only problem I ran into was the huge overpowering of the rest of the system, with the Zapco and Alpine XO gains turned all the way down there was still more than there should be by approx 4dB.
When I put the 2 in series I was able to bring the gains back to 0dB position. I measured 423W with my scope. The overall matching seemed better than either the 3 in series or parallel as well as the 2 in parallel.
I'm assuming that leaving the third sub in place will have more of an effect on the frequency/level response since it is acting as a passive radiator? This may be good or bad.
I am doing some experimentation with high Q BP filters and was thinking of insterting one in the signal chain that was matched to the subs impedance response. I figured that having the 3 in series would be a good real world test, I'm not quite sure what the phasing would be like though?
I've been using a 4" thick multi-layered pad for sound deadening, it makes a huge difference on the sound, even if it is just laying in the trunk.
The rear deck of the car, the hat shelf. I think this is an ideal location for the Zapco piece, it is wide and shallow and fits perfectly there. Here's a couple of pic of what my bro and I have been working on. Sorry for the poor pics.
There are more of the full project for anyone interested.[ July 04, 2004, 12:13 AM: Message edited by: Jaxom ]
07-05-2004, 04:44 PM
#10
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Join Date: Jan 2001
Posts: 2,026
Yeah, the third sub would be acting as a passive radiator. I think that could be good because passive raditors tend to give similar benefits to porting without having to port and calculate all that stuff. a roll off around 25 hz is beautiful, especially if you like classical music with deep pipe organs, or tracks that have thunder playing.
I'm not sure what you mean by
and
Those statements are contradictory. If the sound level wasn't much different, then how did it manage to over power the rest of the system?
It sounds like your having fun playing with different configurations, and your spectrum analyzer. [img]graemlins/thumb.gif[/img]
With the amp mounted on the hat rack, aren't you worried about theives seeing your gear through the back window, busting the class and walking away with that nice piece of equipment? Or do you have some heavy tinting?
What kind of car is it?
I'm not sure what you mean by
Originally posted by Jaxom
The sound level didn't seem to be much different compared to the three in series.
The sound level didn't seem to be much different compared to the three in series.
Originally posted by Jaxom
The only problem I ran into was the huge overpowering of the rest of the system
The only problem I ran into was the huge overpowering of the rest of the system
It sounds like your having fun playing with different configurations, and your spectrum analyzer. [img]graemlins/thumb.gif[/img]
With the amp mounted on the hat rack, aren't you worried about theives seeing your gear through the back window, busting the class and walking away with that nice piece of equipment? Or do you have some heavy tinting?
What kind of car is it?
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