Box Too Big

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jjclark15

Member - Posts: 41

Joined: December 12, 2004

Location: United States

Posted: February 24, 2005 at 11:13 PM / IP Logged

My friend got his box built by a pro for his 4 10s and when I wired them up the subs werent hitting like he nor i expected them too, they didnt respond to quick beats but they pound real hard at the low frequencies. Could it be the box too big and if yes what can we do? Cause he already paid a pretty penny for that custom box.

DYohn

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Joined: April 22, 2003

Location: Arizona, United States

Posted: February 24, 2005 at 11:35 PM / IP Logged

MANY questions before anyone can tell you if it's too big or not: What are the subs? How large is the enclosure? Are there 4 chambers, 2 chambers, or only one? Is it sealed or ported or bandpass? If ported, what's the tuning frequency? And lastly, if he "paid a pretty penny" for the "box," why don't you just go back to the person who built it and ask that they modify it to create the sound you're looking for?

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kfr01

Gold - Posts: 2,121

Joined: April 30, 2003

Posted: February 24, 2005 at 11:35 PM / IP Logged

What is the crossover set at? What is he running for midbass?

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Alpine Guy

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Joined: October 18, 2003

Location: Canada

Posted: February 24, 2005 at 11:35 PM / IP Logged

Did you try calculateing the volume of each chamber? and what size of box does the company reccomend for your subs?

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kfr01

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Joined: April 30, 2003

Posted: February 24, 2005 at 11:40 PM / IP Logged

I'd be willing to bet money the problem isn't the box being too big but is rather a poor transition between bass and midbass. Perceived speed of bass has more to do with harmonics in the upper bass region and into the midbass, correct?

My guess is that 4 10's are really hot relative to the midbass, which is probably totally ignored. The amplifier probably uses a steepish crossover. The result - I bet you have some serious drop off after 70hz or so. The frequencies responsible for the perception of speed are probably severely attenuated relative to the primary bass region.

New Project: 2003 Pathfinder

jjclark15

Member - Posts: 41

Joined: December 12, 2004

Location: United States

Posted: February 24, 2005 at 11:51 PM / IP Logged

the subs are RF P3 DVC4 and the box is sealed and has all subs sharing a chamber and as for dimensions I dont know exactly what volume or any dimensions of the box is. As for midbass he has none still piecing together system has all components Boston Nx series. And mono amp crossover set at Low pass filter at 80hz, Subsonic at 40hz, freq at 80hz approx and 4 ch crossovers set at 125hz higher thanks guys for the quick response.

kfr01

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Joined: April 30, 2003

Posted: February 25, 2005 at 12:01 AM / IP Logged

Alright. Turn off the subsonic filter. You don't need one - ESPECIALLY one that high - with a sealed box.

And yes, you probably do have a severe hole between the midbass and bass. (80 to 125). AND it is probably much larger than that. I bet your 55hz is MUCH hotter than your midbass, even without the 125hz filter.

Try running the 10" drivers with the low pass xo at 100hz. Bump the high pass on the components down to 100hz if you can.

What is the slope of the low pass cross on the amplifier?

My guess is that you've highlighted the problem with 4 10" drivers - you have an unbalanced system.

New Project: 2003 Pathfinder

jjclark15

Member - Posts: 41

Joined: December 12, 2004

Location: United States

Posted: February 25, 2005 at 12:03 AM / IP Logged

24db/octave i think

kfr01

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Joined: April 30, 2003

Posted: February 25, 2005 at 12:07 AM / IP Logged

Wow ... yes ... I bet I've identified the problem. You have a severe gap between the bass and midbass regions. Remember, at the crossover point you are already 3db down. By 160hz you are 24db down. Since the subs are probably much hotter than the midbass you probably have major attenuation from 70 to 200hz.

Also - just to cover all the bases - make sure none of the woofers are out of phase - this could also cause some problems like this.

New Project: 2003 Pathfinder

jjclark15

Member - Posts: 41

Joined: December 12, 2004

Location: United States

Posted: February 25, 2005 at 12:12 AM / IP Logged

I am not a pro at this at all so what would be the best solution to his problem I am not to familiar with all the slopes and how they decrease sound staging or bass response so a Lamens(sp ?) term would be appreciated thanks Kfr01

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