Shop system

I am finally getting my new workshop set up and completed! Just need to get the metal lathe and mill in and i wil be set!!!!!!!

But this last week, I have been getting the audio sytem set up. What a fun time! i built 2 enclosures for a set of orion xtr 6.5 inchers and a pair of Vifa 1 inch soft domes. 18 dB at 3kHz on the tweets and a 6 dB roll off at 2.5 kHz for the 6 inchers. they are actively crossed over at 100 Hz using an old soundstream SX 2 . I lisrened to the sattelites first with some good quality source music and dialed in the right sound with an old audio control 10 band per channel home EQ. (shop acoustics SUCK!) once they had a very nice and smooth sound that really was impressive being run off an old 60 watt per channel onkyo reciever, i moved onto the sub.

Years ago i built an enclosure. it was an dual reflex bandpass for one 12. I remeberd that the gain on this thing was in the area of 7 or 8 dB from about 40-95 Hz. wih a smooth roll off at the lower end. i looked around in my papers for the info on the damn thing and finaly found it (the box design) Well, I built another one. using an old scholl xtr 12 dvc. The end result is KILLER! the enclosure was originally meant for a soundstream ss12 if I remember right, but the orion 12 performs flawlessly. Not sure of the displacement limited power handling on it, but it is handling the 800 watts from the old sony ES amp without a problem.

Played some depche mode, warrant, dream theater , clint black,Time warp (which shook the HELL out of the tools in the toll box!) and some various other personal referance music. The overall sound was rather impressive. Very nice upper frequency response with no serious peaks or dips, and the sub bass rolls in like it should, tight fast and accurate with low end extension that would put 1000 dollar home sub to shame.

still need to do some fine tuning and some sattelite placement corrections for smoother respose, but hell, when your under a truck or running a peice of equipment, i guess it aint that critacal!


this just goes to show what can be done with a combination of 12volt audio and home audio, all of it it least 10 years old (some of it over 25 years old) !!!!!!!

 

Hmmmmm, there is only one dual reflex design that i am aware of. Some folks incorectly refer to it as a 7th order enclosure. It is a enclsure with the woofer mounted internally and the front half is tuned to one frequency, and the back half is tuned to another. Thats the only dual reflex design i am aware of.

But, you want the specs for the box, no problem!

total volume for the back side of the woofer is 2.36 cubic feet, with a port that is 50 square inches in area, and @ 4 inches long

The front side of the enclsure is 2.79 cubic feet with a vent that is 20 square inches in area and @ 26 inches long.

I dont recall the exact tuning frequencies of the box, I did not log that info for some odd reason, perhaps someone who has a program can run the numbers and get a rough idea. But i think it was in the area of 40Hz and 87 Hz

A few suggestions here. I made all the vents rectangular.
The outside dimensions of my enclosure are 27.5x21.5x18, using .75 inch stock. The back side of the woofer has the removable top to access the sub.

Thats the basics of it. I will try and get a pic on here sometime, if i can find my damned camera!

As far as this box goes running other subs in it, you will be taking a chance on launching your woofer if it does not agree with the box!!!!!! As a matter of fact, now that i think about it, this box was NOT designed for the SS12 soundstream, It was for the Xtr 12 SVC. I am running a DVC XTR in it, which has different parqmeters than the single VC version. So I am careful! thats the thing about bandpass enclosures, they can make or literally break a woofer if they are not designed properly!

 

the enclosure design you posted a link too is in fact a bandpass desogn. BUT! it is using the terms "order" which is decieving and not accurate. Anytime a x-over is imposed upon the design, you add another "order". although it is a dual bandpass design in theory, it is not of the most efficient tye either. I have constructed literally hundreds of bandpass enclosures over the years, and the design you posted is rather limiting, due to the size of the enclosure to gain any efficiency, not good for the mobile enviorment, but OK in home use. The vent that radiates into the enviorment is one that must be rather large, due to the air velociy from the woofer and its associated port. Just my two cents on the subject......


But anyway, tonight i run a frequency sweep , unfortuantly I dont have a spl meter or miced spectrum anylzer, but at 45 Hz, the freeking sheet metal on the building was ready to shake itself loose !!!!!

Didnt do it too long cause of the neibghors down the road (I am in the country, but this type of sound travels quite a ways!) Wish i had a tef meter or even the ol audio control rta .....**** I miss them tools.

 

SUNUVABITCH!!!!!!


Got hit by lightning the other night!!!!!!!!!!!!!!!!!!!!!!!!!! could tell by the charred tree next to the shop!!!!!!!took out my sx-2 and appears that I have lost only one channel of my sony amp. the left channel still works , but the right one has no output, period. I had to remove the outputs and the driver for the amp to get it too work!!! LOL!!! Gunna try and get some new ones ordered one of these days

I rewired everything with passive x-overs. threw on a couple of 6.6 mh coils on the sub, wired it up to the good channel of the amp at 2 ohm, tossed a set of 200uF caps onto the sattelites. Still sounds great, and actually the midbass sounds better. but the 6dB roll off on the highs works the satelites pretty hard! those xtr 6 inchers can really move some air!

Lost a little in the spl dept., but I dont crank it that loud very much anyway.so I really dont notice the change.