Gain via dmm - some quick questions

[kero48]

Gents,

I will be setting my gain via dmm this weekend.

A few quick questions, H/U is a pioneer DEH-3300UB, amp JL Audio E1400D, sub is a sundown E8 ver.4 in a slotted custom enclosure.

On the H/U, I know all audio settings, base, mid and high set to 0. Loudness off. How about the cutoff frequency (subwoofer #2 setting). It's currently set to 80 output level +2. Do I leave this alone or does it need to be changed and if changed to what?

On the amp, bass boost off. The slope on my amp is noted as LP Filter. I currently have set to 24DB. Does this get turned off or left at 24DB when setting the gain.

On the amp the LP frequency is currently set to 80hz. Does this setting remain as is when setting the gain or needs to be changed and if so to what?

I generally don't listen to the music louder than volume 40, mostly in the 30's. Would it be better to set at 40, I suspect it goes higher but I am not sure how to tell how high it goes since the manual does not advise maximum volume setting.

Thanks and any other pointers would be appreciated.

My first time doing this so would like to do it right.

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[trumpet 5,000+ posts]

Set the volume at the loudest level before the speakers distort if they're powered by the head unit. You want the most pre-out voltage you can get for the amplifier, and you want to have some room to turn it up for quieter sources. Leave the low pass filter as is. Since a volt meter will not show you if the signal is clipped you really need to listen. A tone heard through a subwoofer should audibly change when the amplifier is clipping.

 

[kero48]

Trumpet, yes, speakers are powered by H/U. Your point is well taken.

With regards to the LPF, when you say leave as is, which one are you referring to, the H/U, amp or both?

Thanks

 

[trumpet 5,000+ posts]

With regards to the LPF, when you say leave as is, which one are you referring to, the H/U, amp or both?Thanks

Just use the filter on the amplifier since it gives you a 24 dB slope. You don't need both.

 

[kero48]

^^ Thanks, does this also hold true to regular listening? I have to check my H/U but I do not think there is an actual off setting for the LPF on the H/U. I think once the subwoofer #1 setting is to normal (meaning on) I have to set something in the LPF.

I will check tomorrow morning and report back.

Sometime in the near future I would like to upgrade the H/U to something with a little more flexibility but for now it will have to do.

 

[kero48]

So I checked this morning, once the subwoofer #1 setting is set to normal, subwoofer #2 setting only has freq cutoff numbers, there is no off option. So I assume I should just leave it 80 for setting the gain and bring the +2 down to 0.

Thanks.

 

[trumpet 5,000+ posts]

So I assume I should just leave it 80 for setting the gain and bring the +2 down to 0.
Thanks.

You might need to have the level setting above 0. Move the LPF to the highest setting on the head unit.

 

[kero48]

^^ Thanks, I believe the setting is 125hz or if you are referring to the leave it at 80 and put the output level to +6 which I believe is the highest.

 

[trumpet 5,000+ posts]

^^ Thanks, I believe the setting is 125hz or if you are referring to the leave it at 80 and put the output level to +6 which I believe is the highest.

No, what I mean is you may not have enough pre-out voltage with the subwoofer level at 0, but you don't want it maxed all the time either. This goes back to having headroom for adjusting to quieter sources. You don't want to leave yourself with nothing but the option of turning the bass down.

If you have a true RMS volt meter you can check the pre-out voltage with a 0 dB test tone and the RCAs unplugged from the amplifier. Positive lead goes to the center pin, negative lead to the barrel. A 60 Hz tone is adequate, and the quickest way to get this is with a tone generator on your phone. I use Ultimate Car Audio App on Android. It's normal for the pre-out voltage to be quite low until just before the max volume on the head unit, so if it only hits 1V when the speakers distort a lot that is acceptable. It's not great, but it's what you have to work with for now.

 

[kero48]

So, here is what I will do on Saturday. I will leave the H/U setting at 80hz +3 and set the gain just to see where things fall.

I can always tweak thereafter but since my gain is set to 60% for the time being (was by ear and probably done poorly) setting via dmm is certainly better than just leaving it at 60%.

For me it's a learning process so I have to start somewhere.

I am very curious to see if the gain was to low to begin with since my sub barely does anything until I turn the volume to about 25 or so.

If loudness is set to LOW, it sounds pretty good. With loudness off, which I would prefer to do based on research, the sub barely moves and almost no air flow out of the port.

In addition, I am having a new smaller enclosure made as the tech at sundown advised the design on their website (which I used) for their 8" subs is more designed for the SA8, not the E8. The tech provided me with a new enclosure design that he feels should work better with my setup. I believe the internal volume is a little less and matches up better with the specs on their website for a ported enclosure for the E8.

Hopefully between the new enclosure and the gain be set correctly, I'll get some bass at lower volumes.

I was so excited to get the sundown and can't really enjoy it yet. You guys and this forum have been a huge help in understanding all the facets of subs/amps etc