So i started to prep my corolla for sound off's and thought i'd do some testing in it to see how i am progressing, so retuned box for the corolla and put the T4-12 back in it and got with
900w 141.0db
3000w 143.0db
5000w 143.9db???????

any ideas with that last score, why did i only jump 0.9db, was expecting it to be 145ish, could the sub be starting to hold me back or could it be something else

what amp/s you running?

Jaycar @ 2ohms 900w
Earthquake phd5000 @ 2ohms 3000w
Epsilon ea5000d @ 0.5ohms 5000w

with 12v batteries, you're more likely looking at around 9-10v after voltage drop during the burp.
which in my experience (have owned both of these amps):

EQphd5000 will make less than 2000w at 2ohms (my D3 only started singing anywhere near 2800w at between 0.3-0.4ohms on 10v after drop) - when i burped it on 0.25ohm the output fuse blew - it was still a fairly new unit so i sold it rather than hardwire the thing and risk bigger damage.

EA5000d makes around 3000w at 0.5ohms (tested mine pulling just over 4kwrms at 0.25ohms with 10v) - these amps are more geared towards burping 16volt systems or daily driving music at 14+ volts, although they do go pretty darn well on 12v too.

realistically, your jump from PHD5k to EA5kD was around 1000watts, but when you count the efficiency of each amp (PHD around 80%, EA5KD with dual torroids at around 70%) you're talking barely 1000wrms difference. Your Voltage probably dropped alot harder on the EA5KD though.

I'd suggest try burping your PHD5k at 0.5ohm and see the difference between the two amps at the same impedance. you might be surprised to see your score won't be much different between the 2 of them because of the more efficient power supply in the PHD. However i don't recommend burping the PHD at anything below 2ohm if it's under warranty. If you're toying with old equipment that won't make you cry if you pop it, then do it.

battery voltage doesnt drop below 11.6volts, and in my puslar there is a 2.2db rise from the quake to the epsilon, was expecting the same not 0.9db, but thanks for your input.

spl is like that.

maybe the box is at its limits, or the subs....

power compression

moved the box around, tried it in about 10 different ways, score only went down.

Sub has found its power limits. You could try retuning the box to suit the extra 5x power you're now running..

dumb question, i thought when you tuned a box you tuned it to the car, never new power had anything to do with tuning a box

normally when you add power, tuning will go up. i went from 49hz with the D3 to 52hz with the EA5Kd

Was that voltage 11.6v at the battery or at the amp?

sub has probably reached its limit

My Seca works best with subs forward port up.

Click to view attachment

ok what model rolla is it and what frequency are you peaking at?
if it is an ae92 then aim to peak around 56 57 hz as that seems to be where they like it alot. i have found this from many hours of testing loudrolla before she was so cruely ripped from the road lol .

smaller box if your going to run more power.

^


yep.


also sounds like the sub has reached its limits as far as power handling.

I found with my old Fusion setup single 12" in my SSS with my Fusion 9001d amp it maxxed at about 140-141db, i then got rid of the 9001d and got myself a DEI 2400D over twice the power and the max i hit with it no matter what i tried to do was 142.6db there was point were turning it up did nothing so i left it at the max point as i didnt want to blow the sub.

Then took same box and amp but put in a DD 3512c and jumped straight to 145's then sold it all dammit....

miss my gear......


As already stated the freq will be different with the diff amps and power wouldnt be much only a few hertz different but it will be different.


SSS_Hoon

Was that voltage 11.6v at the battery or at the amp?

At the amp

My Seca works best with subs forward port up.

May have to build a new box and try it in my corolla, what model is your corolla???

ok what model rolla is it and what frequency are you peaking at?
if it is an ae92 then aim to peak around 56 57 hz as that seems to be where they like it alot. i have found this from many hours of testing loudrolla before she was so cruely ripped from the road lol .

I'm peaking aat 65hz and i have a 1988 ae82 rolla.

smaller box if your going to run more power.

box is 2.1cuft before port ans sub volume, i am looking at droping that 2 or even 1.9cuft.

a single 12 i would go 1.8-2 cube.

as for it reaching its Xmax. i far from think that is the case. i have seen 2x T4 10's doing 146's in a swift off only 3Kw and a little red top battery that ran only 2 runs of 0awg.

so off your single 12'' i cant see why 146's cant be achieved off 3kw also.

having it tuned to 65Hz is more likely your problem thats to high.

tune it down so it peaks at around 55-57 Hz and see the difference then. i reckon just a retune in its current box would see a 2db gain minimum out of it. retune first and see how you go.

then build a box about 1.8 cube tune it to the same frequency of the other box and see the difference then if you gain you stay with the smaller box if you drop then you stay with the bigger box. and then try more tunning on the box that turns out the best.

but yeah re tune test the current box first until you cant get any more gains from it.

thats what i would be doing anyway.

My Seca is a AE92 and with 10s it hit at 57hz, with 12s 56hz and now with the 15s its at 52hz but all worked best forward.

with more power, the sub moves more, so (in theory) you would need a bit bigger box, or try a different frequency.

I was getting 3dB for each double of power right up to 4kW in my old system. then the subs' coils let go.

Im amazed with your box George... Really different design with the woofers so far off the back gate... Really impresive.

What id try is a smaller box for you Khorne. With abit of mucking round with boxes 146s should be do able.

yeah thats in a 92 seca it is a totally different shape to the 92 corolla the only time they come close to being the same car is from the b pillar forward go b pillar back and they are 2 different cars, so what works for you may not work in another car. bear in mind that a seca has a bigger interior volume compared to the hatch edition which is what im sure he is working with.

but i do agree with bringing the frequency down by at least 8 or 9 hz and see how you go. cause nearly every COROLLA not seca ive seen run has peaked in the mid to high 50's area

the car is a ae82 seca, the rf is 65hz the box is tuned to 55hz, both sub and port firing to the back, about 1 foot off the tale gate, and if it helps i burp the car at 64hz

the best way is to tune the box to the rf of the car and go from there. if the box is tuned to 55hz and your going at 64 then i doubt that you are yet to see what it has really got. also try subs and port firing up it may get louder again.

how did you find the rf of the car by the way ?

used a sub in a sealed box and burped it, thats how i have been shown to find the rf is there another/better way.

well major problem number 1 has been solved, it was the termlab, i was running a old version of it termlab so it was reading low, a big thanks to angelo for installing the new version and doing the testing on it while runing the comp yesterday, the difference
jaycar @ 2ohms before 141.0db
after 142.8db

earthquake phd5000 @ 2ohms before 143.0db
after 144.4db

but thankyou to all for all your input and please keep more coming as i have lernt so much in this thred,
things that i will do now:
1. i will also be reducing the the volume of box and retune
2. build some new boxes with ports in different locations
3. finish all the work that is left to do on the corolla.

if there is anything else i should try please mention it as i will try it to see if it works.

so a guess, with my epsilon the sub should be in the 145's would this be pushing the sub's limits, also when i burp it with the epsilon i can smell voice coil.

id say you have pushed it too hard and any longer on that burp and it would have been bye bye t4 lol

if that happens that would make it 2 i would have killed

im yet to kill a sub LoL.


i was putting 2000+ into a 12" fusion powerplant sub rated at a few hundred watts and hitting 142's with it and lasted.

miss the smell of voice coil though lol.

SSS_Hoon

i was talking to somebody the other day about the ratings on my new sub and when i asked how much power i could cram into it he just replied if your not poleing it you don't have enough power...