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midnightE39

thinkign of make a big chance in subs

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ive got one Fi SSD15 on about 1200 rms in a ported box at 37 hz in the turnk of my 525i. i saw some alpine subs on sale online, the new Type-E's for real cheap, I was thinking about buying those 4 12s, or 3 JL audio 13 inch W1s, and sealing them up in a box. what do you think the overall difference in soudn would be? i'm assuming a louder (more surface area, same power) and cleaner (sealed) sound?

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doubt it would be an improvement. you shouldn't be having any issues with your current sub unless the box isn't built probably or your install is bad. they're probably a ton of things you can do to improve your install with what you have now instead of wasting money on more gear. so how about you go over the issues you're having with your current gear and we can make some suggestions

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I would keep what you have.

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A 15 ported is akin to two sealed. 2 sealed 15's wallop 3 12's. Sounds like a serious wtf maneuver to me.

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thanks for the input. yes my SSD does need a new box and ive been designing a new one when i came across the sale.

 

///M5 I have one ported 15, vs 4 sealed 12s at around the same power.

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you sound bored,

 

 build a new box, .. a better design and tune lower. it will be like a whole new stereo

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the problem is that ive not got enough 55-85hz

 

you sound bored,

 

 build a new box, .. a better design and tune lower. it will be like a whole new stereo

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then you dont necessarily have a problem with the sub. your front stage needs work 

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is that the case? because under 100hz is Sub-bass, meant for a sub-woofer, correct me if i am wrong?

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depends how you want to set things up. if you list out everything you've installed  including xover points and so forth maybe we could identify what is causing the issue. 

 

it could be that your have a large bump in frequency response below 60hz which is causing the perception that bass if falling off above that point. what could fix that is designing a new box with a flatter freq. response. 

Edited by lithium

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is that the case? because under 100hz is Sub-bass, meant for a sub-woofer, correct me if i am wrong?

Not by my definition. For me as soon as it is localizable it shouldn't be sub.

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Since your a noob and don't have the Sean to English translation for dummies yet I'll elaborate.

Humans can not localize or in other words tell where sub bass comes from in the vehicle. Most subwoofers actually have physical cut offs well over 200 hz. Some over 500.

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Since your a noob and don't have the Sean to English translation for dummies yet I'll elaborate.

This has my vote for comment of the day. This disclaimer could probably prevent quite a few hurt feelings...

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is that the case? because under 100hz is Sub-bass, meant for a sub-woofer, correct me if i am wrong?

Not really. My PHDs play down to 50Hz with authority. It's install-dependent. Before you go and upgrade the drivers themselves, focus on install techniques. Are all the air gaps in the door sealed up? Have you applied a ring of CCF (sponge rubber works fine and can be found at THD) to mate the front of the driver to the door card? These two steps alone will dramatically improve your sub-100Hz performance out of the front stage.

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Since your a noob and don't have the Sean to English translation for dummies yet I'll elaborate.

This has my vote for comment of the day. This disclaimer could probably prevent quite a few hurt feelings...

 Actually, I am a club DJ. I am fully aware of what he was referring to, i'm a newbie to this forum, and I know more than most people I meet about car audio.

My last setup was 2x Kicker 07CVR12's in a 3.5 cube box port tuned @ 40hz. I had none of these cancellation issues, I'd wanted an Fi sub for a while and decided to try them out with an SSD15, ported in 3 cubes tuned @ 37 hz port back sub up. I believe that the 60-70hz dropoff (where it is most noticeable ~12db) is a result of cancellation from the secondary waves bouncing off the rear of the trunk (near the tail lights) and hitting the waves coming off of the cone at just the right timing, there are only about 4 inches of clearance above the subwoofer cone, the roof of the trunk lined with Q-mat and i'm not sure how much is necessary, my rear deck is mostly metal and simply punching holes in it is out of the question. I have only a decent sized ski hole to vent into the cabin, which was fine with the kicker 12's. Note that when i open my trunk and watch the subwoofer and box, 2 things happen; the subwoofer itself vibrates and moves the box around slightly (wasting energy that needs to be sound) and while the trunk is open, the sub seems to play all the frequencies i give it just fine, So i am assuming my sub up port back orientation is causing cancellation issues in that top bass range.

I'd also like to note that it seems that right after 70 hz the response picks right back up again, i cross my sub and mids at 100hz and it plays everything just fine up to that point. Even higher if i turn the LPF up a bit, i have my subsonic on about 32hz, phase @ 0, no bass boost, my gains are set correctly. 

 

If i multiply the tuning freqency of the box by 2, does that give me the point where the subwoofer cone is moving the most?

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is that the case? because under 100hz is Sub-bass, meant for a sub-woofer, correct me if i am wrong?

Not really. My PHDs play down to 50Hz with authority. It's install-dependent. Before you go and upgrade the drivers themselves, focus on install techniques. Are all the air gaps in the door sealed up? Have you applied a ring of CCF (sponge rubber works fine and can be found at THD) to mate the front of the driver to the door card? These two steps alone will dramatically improve your sub-100Hz performance out of the front stage.

I'm on stock components with only 5.25 midbass drivers, it's a BMW so i belive they are alpine speakers, as was the whole stock CD player, because they actually have a good soundstage and such clarity i'm hesitant to even upgrade them, though i was considering a new pair of some components for the front stage, maybe some fosgates or JL on a 4 channel, and just put some cheap kenwood coaxials in the rear for fill.

 

But that will come, right now I need to get this SSD15 sounding right, as of right now they only outperform the 2 CVR 12s on the lows. I believe it should do better with 1000watts than than 2 kicker 12s on about 600 RMS. Was i mislead when someone told me that larger cones can play the upper bass just fine as long as their motor's are good enough?

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Pictures please

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Since your a noob and don't have the Sean to English translation for dummies yet I'll elaborate.

This has my vote for comment of the day. This disclaimer could probably prevent quite a few hurt feelings...
Actually, I am a club DJ. I am fully aware of what he was referring to, i'm a newbie to this forum, and I know more than most people I meet about car audio.

My last setup was 2x Kicker 07CVR12's in a 3.5 cube box port tuned @ 40hz. I had none of these cancellation issues, I'd wanted an Fi sub for a while and decided to try them out with an SSD15, ported in 3 cubes tuned @ 37 hz port back sub up. I believe that the 60-70hz dropoff (where it is most noticeable ~12db) is a result of cancellation from the secondary waves bouncing off the rear of the trunk (near the tail lights) and hitting the waves coming off of the cone at just the right timing, there are only about 4 inches of clearance above the subwoofer cone, the roof of the trunk lined with Q-mat and i'm not sure how much is necessary, my rear deck is mostly metal and simply punching holes in it is out of the question. I have only a decent sized ski hole to vent into the cabin, which was fine with the kicker 12's. Note that when i open my trunk and watch the subwoofer and box, 2 things happen; the subwoofer itself vibrates and moves the box around slightly (wasting energy that needs to be sound) and while the trunk is open, the sub seems to play all the frequencies i give it just fine, So i am assuming my sub up port back orientation is causing cancellation issues in that top bass range.

I'd also like to note that it seems that right after 70 hz the response picks right back up again, i cross my sub and mids at 100hz and it plays everything just fine up to that point. Even higher if i turn the LPF up a bit, i have my subsonic on about 32hz, phase @ 0, no bass boost, my gains are set correctly.

If i multiply the tuning freqency of the box by 2, does that give me the point where the subwoofer cone is moving the most?

Sit in the back seat and see if that is indeed the problem. If this is the case then making a big change in drivers wouldn't sole the problem, or try turning the box around. Edited by Quentin Jarrell

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Since your a noob and don't have the Sean to English translation for dummies yet I'll elaborate.

This has my vote for comment of the day. This disclaimer could probably prevent quite a few hurt feelings...
Actually, I am a club DJ. I am fully aware of what he was referring to, i'm a newbie to this forum, and I know more than most people I meet about car audio.

My last setup was 2x Kicker 07CVR12's in a 3.5 cube box port tuned @ 40hz. I had none of these cancellation issues, I'd wanted an Fi sub for a while and decided to try them out with an SSD15, ported in 3 cubes tuned @ 37 hz port back sub up. I believe that the 60-70hz dropoff (where it is most noticeable ~12db) is a result of cancellation from the secondary waves bouncing off the rear of the trunk (near the tail lights) and hitting the waves coming off of the cone at just the right timing, there are only about 4 inches of clearance above the subwoofer cone, the roof of the trunk lined with Q-mat and i'm not sure how much is necessary, my rear deck is mostly metal and simply punching holes in it is out of the question. I have only a decent sized ski hole to vent into the cabin, which was fine with the kicker 12's. Note that when i open my trunk and watch the subwoofer and box, 2 things happen; the subwoofer itself vibrates and moves the box around slightly (wasting energy that needs to be sound) and while the trunk is open, the sub seems to play all the frequencies i give it just fine, So i am assuming my sub up port back orientation is causing cancellation issues in that top bass range.

I'd also like to note that it seems that right after 70 hz the response picks right back up again, i cross my sub and mids at 100hz and it plays everything just fine up to that point. Even higher if i turn the LPF up a bit, i have my subsonic on about 32hz, phase @ 0, no bass boost, my gains are set correctly.

If i multiply the tuning freqency of the box by 2, does that give me the point where the subwoofer cone is moving the most?

Sit in the back seat and see if that is indeed the problem. If this is the case then making a big change in drivers wouldn't sole the problem, or try turning the box around.

 I have repositioned the box towards the tail end of the trunk, port facing the cabin. I noticed a slightly better frequency response in the problem area, while overall SPL declined.

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4 inches isn't enough to cancel out ~65 hertz as it's over 17 feet.  If response got better when the box was turned around it's due to transfer function or the vehicle is just a sound barrier and the trunk will not allow that particular area to resonate through the cabin.  If it was rta'd you'd have a better idea of what the issue is. 

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4 inches isn't enough to cancel out ~65 hertz as it's over 17 feet.  If response got better when the box was turned around it's due to transfer function or the vehicle is just a sound barrier and the trunk will not allow that particular area to resonate through the cabin.  If it was rta'd you'd have a better idea of what the issue is.

Which is absolutely normal in an E39. Btw, the stock mids have absolutely no balls. The car will come alive with something real.

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4 inches isn't enough to cancel out ~65 hertz as it's over 17 feet.  If response got better when the box was turned around it's due to transfer function or the vehicle is just a sound barrier and the trunk will not allow that particular area to resonate through the cabin.  If it was rta'd you'd have a better idea of what the issue is.

Which is absolutely normal in an E39. Btw, the stock mids have absolutely no balls. The car will come alive with something real.

I'm sorry, what does RTA'd mean?

 

also, M5///, i would suspect it were the car, but my old setup with subs and port back i did not have any such cancellation issue. 

 

Also after further deliberation I have found the the airspace of the inside of the box is not equal to the VAS of my speaker, I am suspecting this and orientation (sub up/port back) to be the culprit and i plan to build a box at least another half cubic foot larger with the sub and port back.

Edited by midnightE39

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