Less than impressed with L7 and Hifonics Brutus Tuning

[Jtyson]

This isn't an issue with the equipment, but the tuning moreso. I have a 12" Kicker L7 4ohm DVC that I built a custom ported 4.25^3 box tuned for about 35Hz. I snagged the brutus off craigslist and from what I can tell, it is rated for 800 RMS @ 2ohms which is where I have the speaker wired. The speaker is rated for 750 RMS.

I don't have an oscilloscope, so I just use the DMM method to set my gain. Using one of the youtube 40Hz test sounds, the sub kills it. Sounds great. But with actual music, there is a lot left to be desired, and as best as I can get trying to read voltage on regular music, it barely hits at half of the "OK" amount of voltage.

So what can I do? I've turned it up and played regular music and I don't hear anything bad, but I'm no professional and don't really know what clipping sounds like. I don't want to blow anything, but it is tough knowing that it can sound much better, and still leaving it turned way down.

I appreciate any knowledge any more experienced people can give me. I'm pretty much a total noob at correctly tuning stereo equipment. I've been building boxes and enjoying bass for 10 years, but never knew how to correctly tune anything. Never fried a sub, but have toasted an old amp before, so I just don't want to repeat old mistakes or make any new ones if I don't have to.

Thanks in advance!

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[adulbrich 5,000+ posts]

What's your low pas and subsonic set at?

Also, you may be expecting too much sound quality from an L7

 

[Jeffdachef 5,000+ posts]

This isn't an issue with the equipment, but the tuning moreso. I have a 12" Kicker L7 4ohm DVC that I built a custom ported 4.25^3 box tuned for about 35Hz. I snagged the brutus off craigslist and from what I can tell, it is rated for 800 RMS @ 2ohms which is where I have the speaker wired. The speaker is rated for 750 RMS.
I don't have an oscilloscope, so I just use the DMM method to set my gain. Using one of the youtube 40Hz test sounds, the sub kills it. Sounds great. But with actual music, there is a lot left to be desired, and as best as I can get trying to read voltage on regular music, it barely hits at half of the "OK" amount of voltage.

So what can I do? I've turned it up and played regular music and I don't hear anything bad, but I'm no professional and don't really know what clipping sounds like. I don't want to blow anything, but it is tough knowing that it can sound much better, and still leaving it turned way down.

I appreciate any knowledge any more experienced people can give me. I'm pretty much a total noob at correctly tuning stereo equipment. I've been building boxes and enjoying bass for 10 years, but never knew how to correctly tune anything. Never fried a sub, but have toasted an old amp before, so I just don't want to repeat old mistakes or make any new ones if I don't have to.

Thanks in advance!

Try to get access to an oscope or DD-1 if you can. If not you can gain up slowly until it feels like it stops getting louder then back it off a couple clicks, you'll at most be at a soft clip.

Hifonics generally are overrated and if they make their power, its usually dirty power. I'd switch out the amp for something that makes 800-1000 and operates at 2 ohms. Like an alpine m1000 or kicker 1000 or jl 1000 or rockford 1000.1.

Or trade the D4 for a D2

 

[Ridinhi 5,000+ posts]

just curious, what type of vehicle is this in?

 

[massivespl]

Pics of box!!!

 

[Jtyson]

It is in a 1995 Accord. It was actually a Christmas/birthday present for my little sister. She previously had a couple kenwood 12s with a no name amp. She fried the amp, so I figured I'd throw something a little better together for her. I bought the sub and amp on craigslist and built the box myself. Trying to keep it relatively cheap. I'm about $300 into it all. I should also mention I gave her an old 5 farad cap I had in the garage that wasn't being used, so it isn't taxing her electrical system quite as much.

I don't expect much as far as SQ goes from an L7. I'm aware that they tend to be muddy sloppy woofers. She has a blown speaker in her rear deck though and the rattling doesn't bother her enough to change it out, so sound quality obviously isn't of much concern to her.

I originally bought a Kenwood KAC-9104d to run with the sub, but something is loose in it, and it cuts out sometimes. Whack it with my fist and it works again. So I decided not to mess with that and bought the Hifonics. I wasn't aware that Hifonics was considered dirty. I've always seen them pretty highly recommended.

I believe the sub sonic is set at 15Hz and the LPF is at about 80Hz. Bass boost all the way down and level is set about 3/4 up. I know I can max the gain out and turn the bass boost up about 30% before the woofer starts to sound different on the 40hz test tune, but I realize that isn't the right way to go about things.

I do have a pair of 12" DVC 2 ohm L7s that I am selling. I know I could use one of those an run it at 1ohm, but I've read bad things about the Brutus amp at 1ohm. I could probably build her an enclosure for both of them and just get rid of the one I have in her car now, but I'm pretty sure that would take up every single ounce of trunk space she has. She wouldn't care, but last time she left her backpack in the back seat, window got busted and she lost all of her term papers on her laptop, so it'd be nice if she could maintain enough trunk space for a couple bags. Plus then I'd have to find another amp too.

Box isn't anything special. Just a flush mount built to about 4.25^3 ft because that is what I read on here is suggested for the L7, regardless of what the Kicker manual states. On the box building note, I would love to learn how to correctly carpet these things. I can make it to where it looks alright, but I never can get it to look seamless.

View attachment 26551382

 

[massivespl]

Ya idk. U sound like u set the amp up right and the box looks decent. Maybe try messing with some settings on the HU.

 

[Jtyson]

Ya idk. U sound like u set the amp up right and the box looks decent. Maybe try messing with some settings on the HU.

The head unit was set to "flat" for base tuning, then adjusted slightly from there. I don't know what voltage the preamp is, but measuring the voltage while adjusting the bass/mids/treble on the head unit got me within 1 volt of the acceptable voltage according to my calculations. I prefer to err a little on the side of caution.

I just don't know. The sub/box/amp combo sounds impressive if I go by my ear listening to music, but tuning it by the numbers with a test tune, it sounds like $300 in the toilet haha!

 

[Jeffdachef 5,000+ posts]

What head unit volume are you on?

What out of what?

You might want to use a -5 or 6 db test tone instead of a 0 db test tone.

 

[Jtyson]

What head unit volume are you on?
What out of what?

You might want to use a -5 or 6 db test tone instead of a 0 db test tone.

45 out of 62 on head unit volume. Not sure what you mean by test tune decibal. I've only dealt with Hz before, so I'm not aware of the difference or how to compare one to the other.

 

[adulbrich 5,000+ posts]

Do not use bass boost. Also, I'd set the subsonic a little higher

 

[Jeffdachef 5,000+ posts]

45 out of 62 on head unit volume. Not sure what you mean by test tune decibal. I've only dealt with Hz before, so I'm not aware of the difference or how to compare one to the other.

most music is recorded different levels and with bass in normal music, its recorded at -10 to -6 db bass wise. You will rarely ever see a mainstream song that has a fat bass drop thats at -0 db, thats what you are tuning at right now i'm guessing.

Go on audacity and generate a 40 hz test tone at -5 or -6 db and set your gains from there to simulate real music playing.

 

[Jtyson]

Do not use bass boost. Also, I'd set the subsonic a little higher

I hope you don't mind me asking, but why is everyone so adamantly against bass boost? Seems odd to me that something the engineers put into the amplifier should be avoided at all costs.

Also, why increase the subsonic?

most music is recorded different levels and with bass in normal music, its recorded at -10 to -6 db bass wise. You will rarely ever see a mainstream song that has a fat bass drop thats at -0 db, thats what you are tuning at right now i'm guessing.
Go on audacity and generate a 40 hz test tone at -5 or -6 db and set your gains from there to simulate real music playing.

I've seen audacity before. I'll see if I can figure it out. As for what I was tuning with now, it was just the first video on youtube when you search for "40Hz test tune". It is about 5 minutes long. No idea what decibel level it is recorded at

 

[Jeffdachef 5,000+ posts]

I hope you don't mind me asking, but why is everyone so adamantly against bass boost? Seems odd to me that something the engineers put into the amplifier should be avoided at all costs.
Also, why increase the subsonic?

I've seen audacity before. I'll see if I can figure it out. As for what I was tuning with now, it was just the first video on youtube when you search for "40Hz test tune". It is about 5 minutes long. No idea what decibel level it is recorded at

most videos on youtube uses 0 db so its a strong signal compared to actual music signals.

 

[Maky 10+ year member]

I hope you don't mind me asking, but why is everyone so adamantly against bass boost? Seems odd to me that something the engineers put into the amplifier should be avoided at all costs.
Also, why increase the subsonic?

I don't know about the others but whenever I've used Bass Boost it has made the bass coming out of my sub sound absolutely dreadful, Goes from Clean sounding to very 'Boomy'.

Getting more output using correct gain has worked best for me. I set my Bass boost to 0.

As for subsonic I believe it's to cut out the very low frequencies from being played, which you wouldn't be able to hear anyways and subwoofer would otherwise work to produce. Could be wrong on that....