Hi all.

My name is Marcos Barnes and I`m the owner of.

www.globalstreetbassers.com and www.streetbassers.co.uk NOTE: GLOBAL is Under Construction

Some of you may already know me becuse of the Monsterous Purple Escort that does over 150.0dB @ 20Hz and 155.3dB @ 30Hz

Anyway.

I`ve had these 187 10" subs since they were released.

Somebody has just purchased these and I`m building the box for them.

It`s not finished as it need filling and spraying etc.

Here`s the SPL results using the ((((Propper Droppers)))) SPL format.

The following text has been taken from my forum:

Link: or look below: http://streetbassers.co.uk/forum/index.php?topic=2248.0

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Remember this is a box I`d made up for "Halfpintbasser"

Contains two 10" Incriminator Audio subs and 800wrms of power

The following scores were done without the port blockers. In the boot of my Focus.

Only 1dB down from my RF12" with 400wrms less power too, and louder at 20Hz

Average=135.0dB

40Hz=137.9dB

33Hz=135.1dB

25Hz=132.3dB

20Hz=132.0dB

I had to take off 2" off each end of the box to get it to fit in his car. Chevrolet Laccetti 1.8 Sport.

We powered it up, we didn`t use any port blockers, I`m really happy with the scores.

Total Average= 136.4dB + 1.4dB

Peak=138.7dB @ 49Hz +0.8dB

40Hz=136.7dB - 1.3dB

33Hz=136.1dB + 1.0dB

25Hz=134.9dB + 2.6dB

20Hz=136.0dB + 4.0dB (This is louder than my single 12" and with 400wrms less power)

It plays very well.

The car needs to be seriously sound deadened though. It rattles like a bag of bones and tin cans

I was expecting the scores to drop with the smaller box. But it has increased at nearly every frequency, which surprised me.

Makes me want to try the 12" Incriminator Audio 187 series subs. To drop this low in a small box without the use of a port blocker :thumbsup:

BTW: We tested using dB drag Rules.

Remember this is 800wrms in a 30Hz tuned box.

This system hit 140.0dB @52Hz

My 12" 2003 Series RF with 1200wrms could only manage 136dB Pooo!

nice scores

btw. do u know the RESONANT FREQUENCY of the Focus ..

- what r the dimensions of the box and what is the biggest box(WxHxD) u could put in (i am goin to buy a Focus 99) ...

Edited November 16, 200816 yr by Tyan

If you were impressed with those scores, wait until the new 187's are released!!!

Nice job!!

nice scores

btw. do u know the RESONANT FREQUENCY of the Focus ..

I don`t know the resonant frequency of the Focus and I wouldn`t bother either as I`m not into building SPL boxes which take into account the peak resonant cabin gain in which to get high SPL readings.

I build my boxes to have an extended low frequency response which is always at the expense of a drop in dB.

Most focus seem to peak at between 48Hz to 52Hz though. So if you built a box that is tuned to around 35Hz+ that should do quite well in the SPL side of things.

To find out what your cabin gain is you can do this:

1:Plot out a graph. 30Hz to 55Hz / 100dB to 130dB

2:Place the sub in a sealed box. In a large open space. (Beside your car will do)

Get an SPL meter and place it 1 meter or so away infront of the cone.

3:Play the test tones from 30Hz to 55Hz and plot the spl positions, making sure that you keep the volume settings the same.

4:Now place the sub into the car. Close all doors etc and then test in the same way again.

5:You will notice that at a certain frequency the dB levels will be matched with the outside readings and the inside readings. It`s this reading that should be the resonant frequency of your car.

Now you`ve got this frequency you`ll have to build a suitable box to take advantage of this cabin gain as you will not know what to tune to, to get the best out of it.

I used to tune 10Hz below the resonant frequency. Test and then cut 1" of the port length and test again. As you keep doing this you`ll reach a peak at which the spl frequency score (your cars resonant frequency)is the loudest.

There you go. Hopefully the loudest possible SPL box which takes advantage of your cars resonant frequency.

And If like me, you like to drop low bass, then you can always try a port blocker to fill up half the port volume which will tune the box lower and allow the subs cone to be controlled by the port at the lower frequencies.

nice scores

- what r the dimensions of the box and what is the biggest box(WxHxD) u could put in (i am goin to buy a Focus 99) ...

Here`s the box details.

I`ve used 18mm or 3/4" MDF for the box construction.

The box is 3.0 Cu.Ft Tuned to 30Hz

The port including the wall thicknes takes up 0.16 Cu.ft.

The port size is 12" high x 1" wide and is 11" deep with both ends being gradually flared. This port is finished flush with the front baffle which is two layers of 3/4" MDF thick.

BOX Sizes / Internal Sizes.

NOTE: Don`t forget I`ve added another layer of MDF to the speaker mounting face, this allows the speakers to look flush fit and also allows a little more length for the port.

35" Long x 12" high x 12 3/4" deep

BTW: I tend to keep my ports with as little bends as possible or none. I try to balance my ports so that there`s the best possible port area alongside the best length in which to tune low and still have an extremely good transient response.

In your case, if you want SPL you should make the port area as large as possible. By doing this you`ll be tuning the box higher.

You can probably widen the port by an inch, keeping the port length the same and see what happens.

Bearing in mind that the larger your port the less box volume for your subs.

nice scores

...and what is the biggest box(WxHxD) u could put in (i am goin to buy a Focus 99) ...

Funny you should ask that.

I`ve been toying with two box sizes for the Focus.

I`m sticking with this one for my bigger box.

The following box fits in between the parcel shelf and underneath it.

There will be approx 2" gap either side of the box between the suspension pillars.

These are overal sizes using an 18mm or 3/4" thick wall.

35" wide x 21" high x 17" deep.

Giving you a 5.8 Cu.Ft. Box - I`m fitting the amp in the triangular space between the seat back and the box.

You can go even bigger though if you mount the amp on the front of the box, facing the tailgate and building into the angled space as well.

Edited November 16, 200816 yr by Mega Heavy Bass

Hey. About the resonant frequency of the car.

I don`t think it`s worth bothering with. Is it? I`ve been out of the PEAK SPL thing for a while so I`m quite rusty.

I`m not sure if the resonant frequency of the car may be the loudest frequency at the point where the mic is positioned.

If I was to do an SPL box I`d get a sealed box - Play a frequency sweep and see what frequency the cars highest dB reading is.

Then I`d build a ported box to take advantage of the peak frequency based on the results of the sealed box.

The reason I`m saying this is because if you did use the method that I told you about earlier. Your graph within the car will more than likely show a higher dB reading above the cars resonant frequency point.

Not sure if you tune to the resonant frequency or tune lower to take advantage of the resonant frequency peak?

But if you do the Sealed Sweep test I don`t think you can go wrong...

If you were impressed with those scores, wait until the new 187's are released!!!

I`d love to try some of these out.

Do you have the TS parameters for them.

I`m only interested in a few things.

Fs

Vas

Qts

X-max

Coil configuration and power handling.

Sensitivity

^^^^^What`s that supposed to mean then?^^^^^

I'm more impressed with doing more down low, like 30hz and down. popcorn is for i'm tuned in for this topic

Thanks mate

We don`t have these smileys or icons on the U.K. forums. (Not the ones I visit, anyway)

So it was a bit weird for me seing it there.

Good to see other people like to drop low bass

We have a guy over here who is hitting 152.2dB @20Hz with 10x 12" subs in a ported tunnel (6th Order bandpass).

Yet to test another guy called "ICEMAN" (Ian Pinder) apparently his system has been measured in the dB drag position hitting over 155dB @25Hz !!!

WOW!! Just looked at all the smileys for this forum. This set is crazy (in a good way).