Anyone in Sav, Ga area to help with sub box? (1 Viewer)

[schan1269]

What do you mean...
"then the unused pos of the voice coil and the unused neg of the other voice coil connected"
That makes no sense.

 

[mulalleybs]

What do you mean...
"then the unused pos of the voice coil and the unused neg of the other voice coil connected"
That makes no sense.

Meaning the positive of VC1 and the negative of VC2 that were not connected to the amp were connected to each other.

 

[schan1269]

So in "lingo everyone understands"...
You wired it in series.

 

[mulalleybs]

So in "lingo everyone understands"...
You wired it in series.

Sorry, I was merely trying to explain that I had it correctly wired this time instead of wiring it into a 1 ohm load again.. :jawdrop:

 

[schan1269]

Playing a 2.0 source "in 5.1" does the same thing for the bass.
If you have a crossover on the main(or any other speakers) set at 40hz(which I wouldn't be surprised if that is "factory pre-set")...
The sub still has nothing to do till it gets met with 40hz. And I don't care what music you are listening to off a 'puter...
40hz is asking a lot. And you can't compare this to an automotive sound system...as(if you don't have control over the crossover) the pre-set is often 100hz.

 

[mulalleybs]

alright well.. i changed it from lpf to lpf+main, figured out how to set it to 2ch + sw and you were right, it was set to 40 hz so I changed it to 80. Now with the speakers turned to -25db on the receiver and the sub set to +15 db with the gain turned up about half way you can actually see some excursion and hear the bass a little bit. I figured it would be quite a bit louder even with it not being in a box though? But his is a good sign yes?
I also didn't hear any distortion or any of the crackling sounds that is typical of a blown sub.
Another question, just because im curious, but when I set the volume to 0 db does that mean its at 1 watt and playing the 1w/1m rating that the speakers are which is 89 db? I was just trying to understand how the negative db for volume is on here. I know you can change it to regular volume levels, also every change in 3 db on the stereo means its getting twice as loud correct?

 

[schan1269]

Good news is the sub and amp work...
And the sub outside of a box...it is technically nothing more than a fan.
Until you separate the sides(also known as "putting it in a box")...the air it pushes is met by the same air being sucked in...ie..."nothing is created"

 

[Robert_J]

I don't own anything that runs on a 9v battery.

I thought all smoke detectors had a 9v backup battery. When when was the last time you replaced the batteries in them? Plus, you can't have too many batteries. I keep at least 2 years worth of batteries on hand at all times as well as extra food and water.

Another question, just because im curious, but when I set the volume to 0 db does that mean its at 1 watt

No. That means it should be at reference levels. My normal listening levels with network TV with my wife in the room is -25 or 25db below reference. But that is still an arbitrary number unless you know the level the the material was recorded at.

also every change in 3 db on the stereo means its getting twice as loud correct?

Going up 3db requires twice the power. To double the apparent volume requires 10 times the power. The decibel scale is logarithmic. 90db is twice as loud as 80db. 100db is twice as loud as 90db. If 1 watt of power creates 80db, then it took 10 watts to create 90db and 100 watts to create 100db. It will take 1,000 watts to create 110db. All things being equal and ignoring power compression.

 

[mulalleybs]

Ah ok makes sense, I'm trying to decide if I should sell the infinity sm152s now or not. Even though they are quite a bit more efficient than all the other speakers my friend and I both agree that the bostons sound better, not to mention I'm pretty sure the denon can power the bostons to being uncomfortably loud as is.
So I think I just answered my own question lol. I think I'll be able to start making the box tomorrow, the terminal wont get here until tuesday so I'll have to hold off on that part.

 

[Robert_J]

Keep what sounds best to YOU. Look at any thread asking what speakers to buy and you will see us talk about auditions first.

 

[mulalleybs]

alright, finally bought all the materials hopefully there aren't any issues with putting everything together

 

[mulalleybs]

So far.. do you think much more bracing is needed?
http://m551.photobucket.com/albumview/albums/mulalleybs/2012-08-19_17-37-42_993.jpg.html?o=0

 

[schan1269]

The only thing I'd add is a x-brace in there length wise.

 

[Robert_J]

A few cross braces at the top of the box where there are no braces. Then some vertical braces. Finally, one long brace, end to end.

 

[mulalleybs]

alright about to install and wire up sub. parallel or series? sounded pretty good in series with 1 channel when I set it in the box earlier. also on 1 channel the amp doesn't push enough power to harm the sub does it?

 

[schan1269]

This is for you to determine...and neither way is right or wrong...
1. Run the sub in series and run the amp mono...
Pros:
The amp will see a 4ohm load(if i remember correctly a 2ohm VC sub???)
The amp will be easier to "dial in"
cons:
The amp sees a 4ohm load which "slightly" diminishes headroom
2. Run each channel of the sub to each VC
Pros:
Each amp channel sees 2ohm(again, if I remember correctly a 2ohm VC sub)
More power(technically)
cons:
Amp will run hotter
AND...IMPORTANT
Do NOT run the amp mono and the VCs in parallel. That would make the amp see 1 ohm(not 4) and make for a glorious sound out of your sub for probably a day...before the amp dies.

 

[mulalleybs]

Alright just to make sure I understand everything..
Parallel mode: running in parallel mode enables you to feed a signal via one of the inputs into both outputs. each channel drives its own loudspeaker with independent aplifaction, filter and limit characteristics.
So this means I only use the channel 1 input (xlr) to the receiver (rca) bit run 1 vc to each channel. (And you were correct about them both being 2 ohm vcs). Once I run each vc to both channels i have to set the gain for both channels via ch1 and ch2 gain knobs. At this point how do i decide what to set the gain at?
Also it should be noted that Robert said his signal lights rarely cut on while mine cut on almost as soon as you can start to hear bass, does this mean anything really?

 

[schan1269]

Parallel vs series is the speaker end...not the amp end.
Parallel is...
pos amp to pos speaker and neg amp to neg speaker (twice from one side of the amp to both VC on the speaker....this is BAD)...
Series is...
pos amp to pos speaker, that neg speaker to the OTHER side speaker pos, speaker neg back to amp (this is GOOD)
If you run the amp in stereo/dual mono...there is neither parallel nor series going on.

 

[schan1269]

Setting the gain is "where you feel like it"...no more, no less...as long as the gain you pick isn't overdriving the amp(also known as clipping).
I've not looked at the EP4000 in days...
Which light is flickering?
Yellow or red?

 

[mulalleybs]

i thought i was supposed to go + vc1 to + ch1, - vc1 to - ch1 and same for vc2 and ch2?
Or is it supposed to be wired like this?
http://a248.e.akamai.net/pix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/1DVC_2-ohm_2ch.jpg