Do I need more power?

[bigmizzle99]

Subsonic is all the way up, 40 hz . I'm trying to play 40-80 with the sub. The amp has shallow x-overs, 12db, so there is still output above and below these freqs.

[bigmizzle99]

"Certain bass heavy songs" are probably clipped on their own. Unless you've bought the music off iTunes, another trusted music distributor of you ripped it from a CD, you can't guarantee that your music is clean. That's the problem with almost every "bass boosted" song as well, most guys just grab a song and EQ the low end all the way up without even re compressing it...In short: Shit in, Shit out.

But seriously, more power.

Its some Justin Timberlake songs! lol. Lots o'bass! I downloaded FLAC then converted to Apple Lossless and put on iPod. That's how I get and playback music.

[Joe X]

Subsonic is all the way up, 40 hz . I'm trying to play 40-80 with the sub. The amp has shallow x-overs, 12db, so there is still output above and below these freqs.

Your subsonic fr. setting should not be too much above tuning or you will be losing most of the back wave, that's up to half of your power.

Then there's your box design which can take away output potential for different reasons if is not done ok.

Anyways if you deem necessary to upgrade, increasing cone area is the way to go since you are at 2 ohm, I would likely add a second sub and improve electrical to support 1200W, be aware that sometimes you can clip out of poor power. those changes could likely increase your output moderately, if you are expecting a significant increase in output you should then consider deeper upgrades.

[bigmizzle99]

Your subsonic fr. setting should not be too much above tuning or you will be losing most of the back wave, that's up to half of your power.

Can you elaborate on this part? I designed for 36Hz tuning but don't understand how the subsonic affects the backwave.

[slowfkncar]

Your subsonic fr. setting should not be too much above tuning or you will be losing most of the back wave, that's up to half of your power.

Can you elaborate on this part? I designed for 36Hz tuning but don't understand how the subsonic affects the backwave.

If your tuned at 36hz, and ssf at 40, your basically gonna have flat low output. Minus well use a sealed box if your woofer supports it. Yes your enclosure may roll off at 12db,but your subsonic filter might not. Why not tune to 40hz?

[bigmizzle99]

If your tuned at 36hz, and ssf at 40, your basically gonna have flat low output.

If by flat you mean reduced output, yes, I know and that is by design. I tuned it to 36 because I'm not interested in anything below that. This is a car playing music, not a home theater so I don't want to be able to play 20Hz.

Minus well use a sealed box if your woofer supports it.

A sealed box has a completely different response curve, different efficiencies, different sound. It behaves very different than ported.

My original question was around how to tell when to increase power/cone area. I use my ears to tell me, and I since I want to turn it up louder past my clipping volume I drew the conclusion that I need more.

I will take JoeX suggestion around clean power and make sure I'm doing everything I can there. I did big 3 and have 2 runs of 1/0 from battery to trunk. I still have OEM battery and OEM "smart" alternator that does weird charging shit. That might be the problem with the noise I hear at high volumes

[slowfkncar]

You can still tune to 40hz and roll off at 36hz while taking advantage of enclosure backwave for output. If you are gonna have the ssf above tuning, your woofer will always be in the lower side of the impedance scale. Using clean power will help keep things thermally and mechanically under control like joeX stated. Also depending on your enclosure vs woofer EBP it is still possible to bottom out the woofer above tuning with a lot of power. That noise you are hearing is probably clipping as you stated. More clean power will raise that noise to a higher level until the woofer cannot mechanically take it. Also, less voltage drop will let the amp clip at a higher level.

*edit. Btw I would stop at 1.2k and add another lvl2.

[bigmizzle99]

I'm working on designing a new box for (2) DC Lvl 2 12s.

Question for Joe X (or anyone else)...Is there a performance degradation with a port opening on an angled face? In other words the port outlet will be angled.

The issue to overcome is length of port when face is angled. An angled face will snug up to rear seats with minimal gaps in trunk making sealing off easier (plus it puts that extra space in the box). I was thinking to use the middle dimension of the opening as the final length. Is this right?

[hispls]

If I'm at the volume where clipping is (set using a DD-1) and I still want to turn it up, I think it means I need more amp power and a sub to handle that power or adding another sub to achieve a certain level of loudness without clipping.

Am I right?

On certain bass heavy songs, when I'm at clipping, there is some non-musical harshness that I don't like. When I back off a tick or 2, it disappears.

I have a single DC Lvl 2 12 wired to 2ohm and a R1200.1 that is rated at 800w @ 2ohm.

My guess is that you're pushing that sub right up to or slightly beyond its limits. Adding more power to that single sub will do nothing but risk breaking that sub. Once you start approaching thermal limits adding more power gives you very diminished returns due to heat fighting you and raising impedance dramatically.

Don't worry too much about power, for daily music listenings.

If you can properly fit a second lvl 2 12", do it !

If not, maybe a different sub would help : get a DVC2 sub, to run your amp at 1 Ohm. You can try a sub that can handle way more power, use it on 1200 w until you can run more power safely.

That is exactly what I'm thinking. I can do either. If I double the power (by wiring down to 1 ohm) , I'm getting a 3dB increase. What does adding a second driver do, besides more cone area...does that equate to an increase in dBs? If I do that I'll also double the power (approximately) but it would be for 2 drivers.

At your power level, I'd say either getting a better quality 15" to run at 1200W or run a pair of 12" LV2 at 1200W would each get you about the same place.... a bit more output and not sounding like you're straining things when you push it to the amp's limits.

If your tuned at 36hz, and ssf at 40, your basically gonna have flat low output.

If by flat you mean reduced output, yes, I know and that is by design. I tuned it to 36 because I'm not interested in anything below that. This is a car playing music, not a home theater so I don't want to be able to play 20Hz.

Minus well use a sealed box if your woofer supports it.

A sealed box has a completely different response curve, different efficiencies, different sound. It behaves very different than ported.

My original question was around how to tell when to increase power/cone area. I use my ears to tell me, and I since I want to turn it up louder past my clipping volume I drew the conclusion that I need more.

I will take JoeX suggestion around clean power and make sure I'm doing everything I can there. I did big 3 and have 2 runs of 1/0 from battery to trunk. I still have OEM battery and OEM "smart" alternator that does weird charging shit. That might be the problem with the noise I hear at high volumes

I'm glad I'm not the only one who thinks that playing whale song frequencies is pretty useless outside of home theater applications. And yes, in general if you feel you need it louder once you've hit the limits of your equipment definitely means you're ready to upgrade something.

Luckily for you you're a the point in equipment (and likely SPL) that you can get very close to the theoretical +3dB gain from a second sub or doubling power and neither is terribly expensive from where you're sitting. Now when you have 300+ square inches of cone area and 5KW and are dancing around high 140's to 150dB gaining another 3dB becomes a very expensive proposition and often easier gains can be had from box design/tweaking, deadening, and other methods that don't require any sort of doubling.

I can't comment on angled ports since I've never messed with them. My gut tells me it may be somewhat less than optimum so personally I'd try to brainstorm a way to keep either round or all right angles if nothing else but for ease of predicting the results.

[bigmizzle99]

Yeah, thanks bro. I'm leaning toward (2) 12s now and designing the box. The angled port would be a rectangular slot port, just as it leaves the box, the face of the box is angled.

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