subs sound quieter?

hey guys, I have a 97 f150 I put a system in like 2 months ago. its been probably 5 years since I've been into it. Originally I did new kicker 6×8's wired into my head unit All around, 2 kenwood tweeters on an old junky 300 watt pyramid amp I had laying around that works fine, 2 kenwood 12's in a sealed box under the seat and an old school rockford punch 1000.1 mono amp.

The issue im having is i decided i wanted louder subs so I ditched the svc 250 watt rms Kenwoods for some 2ohm alpine type S's. I wired them in series parallel for a final impedence of 2 ohms ( checked to be sure ). For some odd reason these subs sound quieter then my kenwoods did? I kept the gain how it was and even turned it up and the subs sound super loud at low volume then when I turn it up to levels I always turned it up to it sounds quieter then the other subs and even a little distorted if anything. I have my 2 amps separately wired and grounded. the only thing they share is the remote and rcas I went to my rockford amp first then came out and hit the pyramid. what could be causing something like this? I feel it may be voltage drop during heavy bass hits

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I would double check to make sure they’re in phase. Check each sub individually with a 9v battery and make sure they’re moving the same direction. I’ve seen speakers labeled incorrectly right out of the box so just because “they’re wired correctly” doesn’t mean they’re correctly in phase.

I also had a feeling that was a possibility as well. I know I didn't mix up any of my wires but certainly worth a try. thanks

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What size enclosure are they in? Is it possible that the box size was optimized for the Kenwoods and it’s maybe too small for the new ones?

.65 feet per sub is what I'm seeing for this box online..

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I looked up the recommended box size for the type s's and its .85 cu ft. The kenwoods i just pulled out have a recommended box size of 1.27 cu ft. The kenwoods want an even bigger box so that probably isn't the issue. were talking sealed box btw

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By “super loud at low volume,” do you mean that the Alpines are louder at low volume than the Kenwoods were at similar volume, and then quieter than the Kenwoods at high levels?

Could there be cabinet leakage? For example, is it possible that one or both of the Alpines are not as well sealed to the cabinet as the Kenwoods? Perhaps one or more of the screw holes have become compromised and are no longer allowing the screw(s) to be tightened enough to achieve an adequate seal.

Was the combined final impedance of the Kenwoods also 2 ohms? If it was 4 ohms, you might try running just one of the Alpines at 4 ohms and see what happens …assuming the .65 ft^3 per sub means there are separate air spaces for each sub. If it’s a shared air space, it might still be worth a careful try to see what happens, and possibly rule out something weird going on with the amp at 2 ohms.

I’m far from an expert. These are just a few thoughts that come to mind.

the final impedance was 2 ohms as well they were svc wired in parallel. My punch amp is a 1 channel. I only ever screwed the Kenwoods into this box once and these went in all the screws impacted tight. The box is .65 cu ft per sub woofer

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Hmmmm... I'm at a loss...

Maybe the Kenwoods were more efficient? A more efficient driver, fed the same power, will yield more output than a less efficient driver.

I still don't get how the Alpines are “super loud at low volume,” and then "quieter" than the Kenwoods at high levels. It's as though the Alpines have higher sensitivity and lower power handling, while the Alpines actually have more than twice the power handling and likely lower sensitivity than the Kenwoods.

Maybe the Alpines just aren't broken in yet.

How confident are you in the power wiring? Any chance you could have a bad ground or undersized cabling?

That amp only puts out 500 watts RMS at 2 ohms which isn’t even enough for one Alpine type S, but was enough for the Kenwood subwoofers. By turning up the gain you get the required power at lower volumes but then the amplifier is clipping at higher volumes so that may explain your situation. You need a stronger amplifier for those Alpine type S or about 1200 watts RMS to get their full potential.

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Originally Posted by JCsAudio

That amp only puts out 500 watts RMS at 2 ohms which isn’t even enough for one Alpine type S, but was enough for the Kenwood subwoofers. By turning up the gain you get the required power at lower volumes but then the amplifier is clipping at higher volumes so that may explain your situation. You need a stronger amplifier for those Alpine type S or about 1200 watts RMS to get their full potential.

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Makes perfect sense. I assumed it puts out 1,000 watts - based the "1000.1" and on OP having ditched the 250 watt Kenwoods for a "louder" pair of 500 watt Alpines. LOL

I have 4 awg wiring for my power and ground and its grounded super tight, I had to pull a support out under the seat to fit the box and there was a bolt right into the chasis no longer being used I used that to ground it. I know it is different for car wiring but I'm a trained electrician so I understand wiring. the amp runs extremely cool i can run it full volume for an hour and it will barely feel warm.

The amp is an old school ( early 2000's) punch 1000.1 mono. At 4 ohms it will put out 500 watts rms, at 2 ohms it will put out 1000 watts rms which is a pretty good match up for a pair of type S's wired to 2 ohms i would say.

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I tested the voltage at the amp at full volume with the truck at idle it held perfectly at atleast 14.5 volts even on very heavy bass hits i would consider that fine. I checked my resistance again at the amp and its at 2 ohms. I swapped positive and negatives around they are definitely in phase. I swapped the rca's around and Nothing changed. Its all right.

I messed with the tuning a little more on the amp I pretty much set the gain all the way up and turned off the subsonic filter, those are the only 2 settings the amp has. Anyway it sounds pretty damn good right now they are much cleaner and deeper then the kenwoods and really loud. I do think the box size effects the sound would anyone recommend polyfill?

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Originally Posted by arena314

I tested the voltage at the amp at full volume with the truck at idle it held perfectly at atleast 14.5 volts even on very heavy bass hits i would consider that fine. I checked my resistance again at the amp and its at 2 ohms. I swapped positive and negatives around they are definitely in phase. I swapped the rca's around and Nothing changed. Its all right.

I messed with the tuning a little more on the amp I pretty much set the gain all the way up and turned off the subsonic filter, those are the only 2 settings the amp has. Anyway it sounds pretty damn good right now they are much cleaner and deeper then the kenwoods and really loud. I do think the box size effects the sound would anyone recommend polyfill?

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Based on the recommended 0.85 ft^3, and the 0.65 ft^3 of your cabinets, some polyfill should help.

Here's a helpful link: https://www.glasswolf.net/papers/polyfill.html

the only thing about polyfill is it seems to me like some say its a waste of time and some swear it makes a difference in my situation

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Originally Posted by arena314

the only thing about polyfill is it seems to me like some say its a waste of time and some swear it makes a difference in my situation

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If the link I provided didn't help, I don't know what to tell you.

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Originally Posted by arena314

the only thing about polyfill is it seems to me like some say its a waste of time and some swear it makes a difference in my situation

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It's cheap enough to try. If you don't like the results, pull it out and make yourself a nice pillow :)

How does it sound with one sub disconnected?

...and can you visually see if the subs are doing a lot of excursion?

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Originally Posted by arena314

I swapped positive and negatives around they are definitely in phase. I swapped the rca's around and Nothing changed. Its all right.

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Hopefully I’ve read this right and what I’m saying is right 😂 but if the subs are wired in parallel then changing the RCA’s around or the positive and negative connections to the amp won’t affect the phase of the subs relative to each other...?

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Originally Posted by Captain Buff

Hopefully I’ve read this right and what I’m saying is right  but if the subs are wired in parallel then changing the RCA’s around or the positive and negative connections to the amp won’t affect the phase of the subs relative to each other...?

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Unplugging one of the RCAs was my suggestion, but I tend do things by halves.

if one sub was 180'and the other zero, then swapping RCAs would not seem to accomplish a lot. One or the other, of the subs, needs to be retired if they are out of phase.

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Originally Posted by Holmz

Unplugging one of the RCAs was my suggestion, but I tend do things by halves.

if one sub was 180'and the other zero, then swapping RCAs would not seem to accomplish a lot. One or the other, of the subs, needs to be retired if they are out of phase.

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Sorry man I don't know if I 100% understand you. I am assuming here that the subs are in parallel for the sake of amplifier load; and that the 'phase issue' that is being spoken about is between the two subs...sorry if I'm reading this wrong...

If you took a sub out that would obviously change amp load - it would definitely fix the out of phase subs - but create another problem. My thought was to change the wiring of ONE of the subs to the other...

However I just thought about it a bit more right now and realised that I think I'm talking complete bullshit and that this comment is one of the stupidest things I have ever said related to car audio...whoops...

Sorry...for what it's worth I was trying to help! I can actually blame DIYMA this time though...for exposing me to a guy who is a psychopath and his pawns who introduce themselves to a conversation by abusing me for answering a comment that has been posed to me. Can't delete my account but I have removed all information and set all privacy to max. I have had a shitful of that place.

Apologies...pretty sure my comment is VERY wrong and from there it goes to a little bit of an off topic bitchy whinge...my bad.

Quote:

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Originally Posted by Captain Buff

Sorry man I don't know if I 100% understand you. I am assuming here that the subs are in parallel for the sake of amplifier load; and that the 'phase issue' that is being spoken about is between the two subs...sorry if I'm reading this wrong...

If you took a sub out that would obviously change amp load - it would definitely fix the out of phase subs - but create another problem. My thought was to change the wiring of ONE of the subs to the other...

However I just thought about it a bit more right now and realised that I think I'm talking complete bullshit and that this comment is one of the stupidest things I have ever said related to car audio...whoops...

Sorry...for what it's worth I was trying to help! I can actually blame DIYMA this time though...for exposing me to a guy who is a psychopath and his pawns who introduce themselves to a conversation by abusing me for answering a comment that has been posed to me. Can't delete my account but I have removed all information and set all privacy to max. I have had a shitful of that place.

Apologies...pretty sure my comment is VERY wrong and from there it goes to a little bit of an off topic bitchy whinge...my bad.

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It is easier to just unplug one and hear what happens before diving into wiring... but I am a lazy man.