Not hitting 100db :|?

[rickyfromthe407]

Ok, so I am kinda distraught at the fact my system of 4 10"s is not hitting even 100db.

I have a custom built box which is at .82cf. per chamber, and it holds the 4 Memphis Mojo 10"s.

Now before you bash box size, I did in fact email Memphis tech support and got a spec sheet for the subs, they say .85 is the recommended sealed box size for my subs.

So yes, this box is sealed, 4 chambers, 4 subs.

I know that on a TermLab meter it would measure SOUND PRESSURE and on a Microphone on a Laptop or something it would measure DB.

Now maybe I am confused, but it seems like 4 10"s in a sealed box, should be hitting more than 92DB which is what I was getting on my MacBook Pro and also from an APP on my iPhone.

Maybe I am doing it wrong, but man, seems like I should be hitting 120db.

Really upsets me that I went through all this work and it wont hit 100db. But I could be doing something wrong...

My next question:

I have a SoundStream EGA1700D amp running these subs, since they are Dual 4OHM subs I can only get them down to .5ohm or 2ohm.

My amp wont run .5ohm so I chose 2, at 2ohm it pushes 850watts through these subs. STILL at 850watts I should be hitting more than 100db. eh?

Now in all honestly, I am a :noob: in the car audio scene, so I am still learning a lot, and could use some helpful advice.

My amp also cuts into protect mode sometimes, I am not really sure what is causing it, but I got 1/0 all around, power, ground, big 3 etc. Got a XS D6500 in the trunk, so I know I have the electrical. My voltages dont drop too much, But I havnt been driving the car it is my second car so I am not using it until I get everything settled, so I am not jumping on it yet. But any ideas as to why the amp keeps jumping into protect mode? Theres no short between power and ground, or between the speaker wires at the terminal on the amp. Also, its not because heat either, the amp is still pretty chilled, not warm at all.

What do you guys think? I know it's a lot, but your help is greatly appreciated!

[DC-Derrick]

what kinda car do you have? trunk suv or hatch?

in the vehicle, what way do you have it facing?

[Alex K]

oh god...

[Rebel4055]

Well the apps and such you tried it on won't tell you the correct thing, only a termlab would do. Plus you have them in a sealed box.

And for your amp to cut into protect sometimes could mean that the subs are wired wrong, bad ground, or you just set the gains a bit too high.

Or a coil is going bad on one of the subs.

[dugee81]

i wouldnt use any kind of laptop, iphone, ipad, etc for measuring Sound Pressure Levels. think about anything youve tried recording, how many DB's do you think youve produced into that little mic before it starts to distort? you should try to find a shop around your area that has something a little more accurate before you start putting yourself down

[rickyfromthe407]

what kinda car do you have? trunk suv or hatch?

in the vehicle, what way do you have it facing?

Car is a 95 Honda Civic EX 2Dr Coupe

I got two on a 45degree slant facing the rear when you open the trunk, as well as 2 facing the cab when you drop the rear seats.

oh god...

Thats right.

Well the apps and such you tried it on won't tell you the correct thing, only a termlab would do. Plus you have them in a sealed box.

And for your amp to cut into protect sometimes could mean that the subs are wired wrong, bad ground, or you just set the gains a bit too high.

Yeah, I didnt think my iPhone was too accurate. But even with a sealed box, i would think FOUR 10"s would hit pretty loud. I know I have heard some loud systems and I think mine is up there, I know its not near anything of meade's or most of the guys on the forum, but to me its pretty decent.

If the subs were wired wrong, wouldnt it be on whenever the subs hit? Bad ground for the amp, I just upgraded it to 1/0 grounded to my batt.

Could be my gains though.., Do you suggest just turning down the Level screw on my amp?

[rickyfromthe407]

i wouldnt use any kind of laptop, iphone, ipad, etc for measuring Sound Pressure Levels. think about anything youve tried recording, how many DB's do you think youve produced into that little mic before it starts to distort? you should try to find a shop around your area that has something a little more accurate before you start putting yourself down

Thanks Man! I appreciate the boost of confidence! Its been getting to me, spent all this money, time, labor etc trying to get everything perfect, seems nothins perfect! LOL.

[Rebel4055]

Yeah, I didnt think my iPhone was too accurate. But even with a sealed box, i would think FOUR 10"s would hit pretty loud. I know I have heard some loud systems and I think mine is up there, I know its not near anything of meade's or most of the guys on the forum, but to me its pretty decent.

If the subs were wired wrong, wouldnt it be on whenever the subs hit? Bad ground for the amp, I just upgraded it to 1/0 grounded to my batt.

Could be my gains though.., Do you suggest just turning down the Level screw on my amp?

How did you gain the amp to begin with?

[DC-Derrick]

naa, sealed box in a trunk car, it wont be that loud.. especially on 800w, but i would think it would be alittle more than 100 db.. its probably around 120-125ish if i had to guess..

but thats just a guess, if some one is in your area with a TL let them have at it and test it out

[rickyfromthe407]

Yeah, I didnt think my iPhone was too accurate. But even with a sealed box, i would think FOUR 10"s would hit pretty loud. I know I have heard some loud systems and I think mine is up there, I know its not near anything of meade's or most of the guys on the forum, but to me its pretty decent.

If the subs were wired wrong, wouldnt it be on whenever the subs hit? Bad ground for the amp, I just upgraded it to 1/0 grounded to my batt.

Could be my gains though.., Do you suggest just turning down the Level screw on my amp?

How did you gain the amp to begin with?

My amp doesn't have an exact Gain setting, the Gain setting for my amp is the Level screw. Have a look at the manual for the amp at this link:

http://www.soundstream.com/manuals/AMP/EDGE%20%20manual/EDGE%20%20manual/digital/Edge-Digital.pdf

naa, sealed box in a trunk car, it wont be that loud.. especially on 800w, but i would think it would be alittle more than 100 db.. its probably around 120-125ish if i had to guess..

but thats just a guess, if some one is in your area with a TL let them have at it and test it out

Even with the seats dropped though, I agree i think it should be around 120. I will look for someone with TL, theres a few Audio shops around, have to call em up, then look around on the forum for some guys in the area.