Sub/amp question

[sodak76 0]

Hi, I posted here awhile back having trouble getting any output from two dcon 12 d4s in a sealed box. I tried them out in a ported box I had for my ED subs and there was a definite increase in output. But there are a couple of things I need your opinions on.

The box is not spec for the dcons. Basically it's a 2.8 cu ft shared sub chamber with a 3x13x40 slot port which should give it a tuning around 28Hz. So it's undersized by about .7 cu ft from spec. Now the main issue. I have been running these at 4ohms off of a PPI A600 and while it sounds good, the amp runs VERY hot. Granted it always has, as has any of the Art series I've run at 2ohms stereo or 4ohms bridged. The other part of this issue is the sub seems to still be slightly out of phase with the other speakers in the car. It's the Alpine system in the '11 Charger, and one of the specs mentioned that the speakers were phase aligned for the vehicle. My solution is to replace my PPI with a Phoenix Gold Ti2800.1 Class D mono amp. The Class D should help with the heat issue and the amp has a phase adjustment from 0-180 degrees so I can dial in the sub to match the other speakers. The problem is the amp is rated for 800w @ 1ohm and the birth sheet says 1100w @ 1ohm.

My question is, with this box being undersized and the amp being almost double the rated power for a pair of dcon 12s, am I going to run into problems? Is an undersized ported enclosure similar to an undersized sealed enclosure in that it takes more power to run it? Has anyone run that much power into a pair of dcons? I need to know soon as I have a niece who coming tomorrow and can pick up the amp for me (it's 200 miles away). Any help is greatly appreciated.

[EPerez 236]

It doesn't matter if you have a 10k rms amp on them. Just set the gain to right before you hear the sub stress. You will be fine with that amp. Just because its rated for what it is doesn't mean it will put out that much power. Like I said make sure you use your senses to know when the subs are being pushed to hard (listen for distortion, smell coil).

I would suggest a new box though. That way it's made exclusively for you dcons. If you need a box design I can definitely help you with that. Then if you or someone you know can build it.

[sodak76 0]

The reason I asked is I tried running a pair of the old Pioneer IMPP subs at double their rated power once, and even with the gain on the bottom they would still bottom out. Mainly I was wondering if SSA underrated their subs to an extent. As far as the amp's power rating, the birth sheet should mean that's the actual output. I know PG's new thing is having their amp's out put be around 30% higher than the rating.

As far as the box the only way I could do a spec box for a dcon is if I went with one instead of two. If it comes down to it, my old ED Kv series 12s will work with that power and that box, and I'll use the dcons for something else. I just wanted to make sure if I tried them out I wouldn't be frying the coils or popping the suspension.

[EPerez 236]

You must of had the settings wrong on the amp and/or box was shitty. I guess ssa underrated their subs if you want to say since they are proven to take a shit ton more power than their rated but in reality it's not needed AT ALL. When I said just because it's rated for 1000rms at 1 ohms doesn't mean it has to or will always put out that much at 1 ohm. Honestly who gives a fuck if its underrated by 30% lol for a daily setup you wouldn't hear 1000rms from 1300rms.

Why can you only go with one? What's the reason for that? Any failure of the sub is always user error either by setting things up wrong or not knowing the signs of the subs stressing like mentioned above. It you can manage both of those you will never have a sub fail on you.

[Shogen 325]

THe power really shouldn't be an issue.... usually bottoming out happens first with wrong tuning/SSF/amp gain settings being incorrectly set.... Look to that first... also re-check wiring to make sure none of the subs are out of phase .... shit happens and we all get excited when throwing in something new ... I've not done that but I have wired to .5 ohm once but realized it by chance.... BOOM !!! I got lucky!!!

[sodak76 0]

You must of had the settings wrong on the amp and/or box was shitty. I guess ssa underrated their subs if you want to say since they are proven to take a shit ton more power than their rated but in reality it's not needed AT ALL. When I said just because it's rated for 1000rms at 1 ohms doesn't mean it has to or will always put out that much at 1 ohm. Honestly who gives a fuck if its underrated by 30% lol for a daily setup you wouldn't hear 1000rms from 1300rms.

Why can you only go with one? What's the reason for that? Any failure of the sub is always user error either by setting things up wrong or not knowing the signs of the subs stressing like mentioned above. It you can manage both of those you will never have a sub fail on you.

The box on the pioneers was a sealed with no leaks, 3/4" mdf, glued, screwed, and caulked. The headunit never went over 3/4 and was not overdriving the amp. But what I heard was not a musical sound, more like a buzzing plastic. They were two 150w 8ohm subs in parallel on a PPI A600. Once I got ahold of an A300 they sounded fine.

As far as the power, I don't necessarily need 1100w, but that's the lowest power available with the phase adjustment feature. And I realize that even doubling your power only gets you 3dB, so a 300w difference is negligible as far as output, what I am worried about is if that extra power will push the drivers past it's thermal and/or mechanical limits.

The reason I don't want to go to one sub is losing half my cone area. Anytime you double the amount of drivers you're looking at around a 6dB gain (or a perceived doubling of the volume). I used to install professional sound systems for 12 years, and have been putting in car systems for myself for around 22 years, so it's not new to me. But up until now I've always done enclosures to spec and matched the amps power to my drivers. But I this situation the enclosure needs to be removable, and I need to be able to adjust the sub's phase to bring it in line with the rest of the system. So that's why I'm in this situation. Like I said earlier if going to be too risky I have other uses for the subs in the future, but I hoped to not have them sit around for a couple years while I restore the other car.

[sodak76 0]

THe power really shouldn't be an issue.... usually bottoming out happens first with wrong tuning/SSF/amp gain settings being incorrectly set.... Look to that first... also re-check wiring to make sure none of the subs are out of phase .... shit happens and we all get excited when throwing in something new ... I've not done that but I have wired to .5 ohm once but realized it by chance.... BOOM !!! I got lucky!!!

No, it's wired correctly. All the speaker wires have red & black heatshrink at the ends to avoid that, made sure each driver is wired in series the same way (series/parellel for a final 4ohm load), and am using a barrier strip inside the enclosure instead of trying to stuff 2 wires under the speakers connectors. Borrowed a coworkers o-scope to set all the gains so that's not an issue. I've been working on this for around 4 months in my spare time and have rechecked it more times than I can count. The biggest difference was that up until this weekend I was using a sealed box built to spec, and it just didn't have enough output to overcome the vehicle's insulation. Apparently Aaron had a Mercedes (which uses the same frame as my Charger) and he said they were a bear to get output out of them. I'd love to do a spec box but if I did it wouldn't be removable and that's a must for me.

[EPerez 236]

You must of had settings wrong on the amp then. Probably wasnt due to box since it was sealed. Forgot it wasn't ported. Not really sure what the buzzing sound you mean? Can you explain that a little more? Must of been something wrong with the amp since it worked fine with the other.

You don't need to give them the extra power though. Just make sure the settings on the amps are correct and you won't have to worry about anything going wrong.

I mean what's holding you back with goin with 2 ported? And to correct you on that, it's a 3db gain when you double cone area.

You don't need to throw your experience out there because obviously if you have been doing this for so long you would already know these questions your asking.

Are you talkin about the phase knob on the amp (0-180 degrees)? I'm pretty sure that's only there so if you invert the subs and allows you not to have to re wire the sub backwards.

[sodak76 0]

You must of had settings wrong on the amp then. Probably wasnt due to box since it was sealed. Forgot it wasn't ported. Not really sure what the buzzing sound you mean? Can you explain that a little more? Must of been something wrong with the amp since it worked fine with the other.

You don't need to give them the extra power though. Just make sure the settings on the amps are correct and you won't have to worry about anything going wrong.

I mean what's holding you back with goin with 2 ported? And to correct you on that, it's a 3db gain when you double cone area.

You don't need to throw your experience out there because obviously if you have been doing this for so long you would already know these questions your asking.

Are you talkin about the phase knob on the amp (0-180 degrees)? I'm pretty sure that's only there so if you invert the subs and allows you not to have to re wire the sub backwards.

The first part I was talking about was the Pioneer subs I'd had a few years back. The buzzing sound was the subs bottoming on the 600w amp. Just barely moving the gain off of bottom and they were bottoming. By dropping down to an amp that matched their rated power the problem went away. There is such a thing as overdriving a pair of subs. At some point you exceed the sub's thermal and/or mechanical limits. The 600w amp I used on those Pioneers worked fine on other subs that required more power.

The reason I can't go with two dcon 12s ported to spec is because it will not fit through the trunk opening. Someone suggested I assemble it inside the trunk, but the enclosure needs to be removable, and I need to be able to get at my battery and spare tire. The enclosure and amp will work with my ED subs so I may just go back to them and leave the dcons for my other car.

The phase adjustment knob is not just 0 or 180 degrees, it's anything in between (30, 45, 60, 90, etc.). I've already used the 0 or 180 degree phase switch on my crossover, but they are still out of phase from the stock speakers. The audio systems amp also contains DSP that they used to phase align the speakers to the car. I'm just trying to match my sub to them.

As far as doubling the speakers, yes simply doubling them will net you 3dB, but in this case I'm also halving the impedance so that's another 3dB. It may not be the case for every amp, but the A600 doubles the power (3dB) when the impedance is halved. Besides that there's still the matter of half the cone area being lost by going with one sub. The amount I'd gain by going with a single sub (right now each sub is short .35 cu ft) would be negligible compared to losing one of the drivers.

The reason I am asking these questions is because, as I said earlier, whenever I had done an install for myself, I went completley to spec, both in terms of enclosure and power. This is also the first time I'm simply adding an amp & sub and integrating them into the factory system, which in this case is an amplified system and phase aligned for the car. Any other time I have always replaced the entire audio system, so phase issues and such weren't an issue because I had installed everything myself so I knew what I was dealing with. Here the factory has installed everything but the low end drivers. I wish I could replace the audio system completely, but first the car still has a lot of warranty left on it, and second this car has a touchscreen in the dash that not only controls the audio system, but also the temp controls, heated seats, and settings for the keyless entry, remote start, security, etc. Basically I'd be getting rid of alot of the positive things about the car.

Edited May 22, 2013 by sodak76

[EPerez 236]

Amps don't have to be matched to the subs rating at all. Like I said you could have a 10k rms amp on them as long as things are set correctly. Maybe the amp was fucked up resulting in the buzzing.

What are you max dimensions. Is the .35 under the optimal or non optimal recommended? I thought you meant .7 under each lol I'm not sure what you mean, are you saying halving the impedance meaning more power? I was saying if just doubling cone area it will be 3db gain. That's in a perfect world. May not be true in real world installs though. But doubling the power will get you a 3db gain too which I think it what you mean.

I would rather have a single sub in the best box you can have vs 2 subs in an okay box. I've done that before with 2 ssa zcons. They were in a box that wasnt the best so I switched to 1 and it was way louder and sounded a lot better.

I have a 2012 fusion with all the stock stuff like you have and I wanted to keep it. I bought the lc2i and tapped into the rear speakers. I have my sub and amp on it now and works perfect. I also have my coaxials (until my crescendo comps come whenever that is lol) on an amp as well. I have no problems and I didn't have to do any phasing or anything like that.

[EPerez 236]

Also can you take the plastic and rubber around the trunk opening to get more room. I did that and was able to get about 1.5 inches in height and 2 inches in width extra!

[sodak76 0]

Even with the amp on the lowest gain setting, you can still overpower a speaker. The gain is not a volume control, it's for impedance/signal matching the output of the source unit. Granted if you kept the source units signal low the amp would only have so much to amplify, thereby giving you a lower output power. But then you'd have to adjust your other amps to blend your subs to your component speakers.

When I said .7 cu ft that was for the pair (.35 each). The minimum recommended volume for a dcon 12 ported is 1.75 cu ft. The enclosure I'm using has 2.8 cu ft for the subs, which is .7 cu ft under the minimum recommended 3.5 cu ft.

I don't know if removing all of the trim will make it possible to fit the box, because if I have to remove the box for a flat tire or to haul something I may not have the time or tools to remove them. I live in South Dakota, and if I get a flat in the middle of winter where it can get down to -20 degrees, I'm not going to freeze my ass off trying to pull out my sub box. There's no getting around that.

The amp is fine other than running hot. I've used it on several systems since that without an issue. All the Art series (and most any AB amp from back then) will run hot on anything lower than 4ohms stereo. That's why they pushed (unsuccessfully) to do liquid cooling on their amps. I may try a single dcon ported, but considering my EDs play just as loud and actually cleaner (since they are in the proper box) it doesn't seem worth the effort to build another box in the hope that it might play a couple dBs louder. I'll just use the dcons for another car.

All I wanted to know was if with a smaller than recommended box would the amp I plan to use be a bad idea or not. I appreciate your trying to help, but I've been working on this for near 4 months now, and I almost went with another brand sub, but I went with these because of some positive reviews on the dcon's performance in a sealed box, not because I necessarily like a sealed box, but because I needed something small enough to be easily removed if I needed to. Had I known I would have to go ported from the get go, I would've went with two tens ported, but at this point it's either save them for a car that I can put a properly sized box in, only use one sub, or sell them and find something else. Sorry if I'm coming off like a dick but after fighting with this system for so long it's wearing on me. I just want it to be done, no more experimenting, just listening to it.

[sodak76 0]

I have a 2012 fusion with all the stock stuff like you have and I wanted to keep it. I bought the lc2i and tapped into the rear speakers. I have my sub and amp on it now and works perfect. I also have my coaxials (until my crescendo comps come whenever that is lol) on an amp as well. I have no problems and I didn't have to do any phasing or anything like that.

Like I said before, the system in my car is an optional system designed by Alpine. They apparently have some digital processing in the system to phase align the speakers for the interior. I'm using a PAC Audio interface that gets the signal from the signal bus before it's amplified. Otherwise the sub would be affected by the tone controls and whatever they set for the factory sub's crossover frequency. Most factory systems, even one like Bose, Infinity, & JBL, only have amplifiers and crossovers and upgraded speakers. This is apparently a new thing trying to optimize the system for the actual interior. The problem is it also means it's much harder to change it. Even the component speakers are different, with each having a 2ohm impedance, so it harder to find replacement speakers if you don't want to replace the factory amp as well.

About the 3dB gain from a second speaker, in my case having the impedance does mean a doubling of power as well. A PPI A600 makes 150w @ 4ohms, 300w @ 2ohms, and 600w @rohms bridged. If you went the opposite way and added a second sub but put them in series, there would be no gain at all since while you are adding a second driver (+3dB), you're doubling the impedance which halves your power (-3dB).

[///M5 2,833]

Box and amp are independent. Box I'd build more optimally, makes no sense to shoe horn something into a non-ideal situation. If you can't make the box fit selling and getting 10's makes sense.

As for the power, not sure why you don't get it. Turn the gain down. I've teested 8w tweeters on my 1000w Crown. It's my lab amp and what I use for testing/designing etc. Also, don't believe birth sheets. No standard are they tested to. The whole "under rated" sub or amp is a joke as well which you outlined in the inaudible difference it will gain you

[EPerez 236]

Yea I know it's not a volume knob and only matches up the voltage on the hu. I think we're just saying the same thing different.

For mine I just had to remove 6 push clips and the whole thing came off so was just throwing ideas out there since mine didn't need any tools.

Yea I understand your frustration with not having a system work like you planned. I had the 2 Zcon 12s but it wouldn't work like I hoped so everyone suggest just 1 ported so I went that way and was more than happy. If I were you I'd just try one ported. If you need I can design the box and it should be only ~40 dollars to make if you build it yourself. Worth a shot and if not you can sell the box for more lol

[EPerez 236]

Box and amp are independent. Box I'd build more optimally, makes no sense to shoe horn something into a non-ideal situation. If you can't make the box fit selling and getting 10's makes sense.

As for the power, not sure why you don't get it. Turn the gain down. I've teested 8w tweeters on my 1000w Crown. It's my lab amp and what I use for testing/designing etc. Also, don't believe birth sheets. No standard are they tested to. The whole "under rated" sub or amp is a joke as well which you outlined in the inaudible difference it will gain you

Finally someone comes in to help say what im saying lol maybe he will get the power thing now.

[sodak76 0]

Box and amp are independent. Box I'd build more optimally, makes no sense to shoe horn something into a non-ideal situation. If you can't make the box fit selling and getting 10's makes sense.

As for the power, not sure why you don't get it. Turn the gain down. I've teested 8w tweeters on my 1000w Crown. It's my lab amp and what I use for testing/designing etc. Also, don't believe birth sheets. No standard are they tested to. The whole "under rated" sub or amp is a joke as well which you outlined in the inaudible difference it will gain you

The sub was bottoming out with the amp gain at minimum. The only way I could get around that was to lower the HU's volume control, which meant I then had to really bring up the gains on my high pass amps to the point they were almost at maximum. It also meant less fine control on my HU volume control. By going down to an amp with half the output, it allowed me to have full use of my volume control, and keep my other amps gains off the top. Do you see what I'm saying here?

And as far as the amp, it has worked fine with other drivers that required more power than the Pioneers did. In fact it's still in use today in one of my brother's cars.

Edited May 23, 2013 by sodak76

[sodak76 0]

Yea I know it's not a volume knob and only matches up the voltage on the hu. I think we're just saying the same thing different.

For mine I just had to remove 6 push clips and the whole thing came off so was just throwing ideas out there since mine didn't need any tools.

Yea I understand your frustration with not having a system work like you planned. I had the 2 Zcon 12s but it wouldn't work like I hoped so everyone suggest just 1 ported so I went that way and was more than happy. If I were you I'd just try one ported. If you need I can design the box and it should be only ~40 dollars to make if you build it yourself. Worth a shot and if not you can sell the box for more lol

I wish that were my situation. The trunk in these Chargers is a bitch. Everything is with those friction pins and the panels are set up so that you can't get your fingers behind them to even try removing them without tools.

What are you paying for a 3/4" sheet of mdf? The cheapest I found is 90 miles away and $55 for a 4x8 sheet. By the time I add screws, terminal, wiring, glue & carpet I'm looking at around $80-100. And unless I eBay it there's really no one else around here that I can sell it to. Anyone else who is into stereos around here would rather get a prefab box. It sucks when you're in the boonies, trust me. If I was still in the town where I used to work it probably wouldn't have been a problem.

[EPerez 236]

I thought of that as soon as you posted lol where I'm at its 34 a sheet so like 40 for everything. I paint my boxes so I always have extra paint. Ohh and don't use terminals. Just cut a hole in the box and caulk it up when you push wires through. Saves money and is just as effective. You know for future reference.

[sodak76 0]

I thought of that as soon as you posted lol where I'm at its 34 a sheet so like 40 for everything. I paint my boxes so I always have extra paint. Ohh and don't use terminals. Just cut a hole in the box and caulk it up when you push wires through. Saves money and is just as effective. You know for future reference.

I just prefer a terminal cup for quick connect/disconnect. Besides those only cost about $5, that's the cheapest part of the box cost for me. Anyways, thanks for your thoughts, I'm gonna stick with my EDs for everyday and put the dcons in my Olds.

Edited May 23, 2013 by sodak76