bracing volume difference

[kanemack]

so this one should be pretty easy for you guys. i built a center channel tritrix at 23L and ported it. i never really gave the bracing much thought, as i didn't think it was gonna be as great as it is. i did 3 windows, and man this thing has huge bass. so then i decided to build 2 more same box size, but i got fancy with the bracing. i went with 3 round cutouts rounded over. the bass isn't where it should be on the 2 newer ones. the calc says that the square brace is 44.803 inches cubed. the round one is 77.09. would this make that much difference? if so how do i gain the space back? more fill? oh well the sound great as is, just wish i could get a little more bass out of them. any help, as always, is appreciated.

[joeybutts]

Re: bracing volume difference

have you swapped the speaker in place of the one you enjoy to see if it is a placement issue? Do the new braces impede the port at all or the back of the woofers? Did you place the stuffing in a different manner?

There are lots of variables that could lead to this perceived/measured difference.

[kanemack]

Re: bracing volume difference

have you swapped the speaker in place of the one you enjoy to see if it is a placement issue? Do the new braces impede the port at all or the back of the woofers? Did you place the stuffing in a different manner?

There are lots of variables that could lead to this perceived/measured difference.

all 3 speakers are in freespace with at least 5 feet to a wall. i weighed the fill so they are fairly even there. i had about 9 ounces in each cab. the odd thing is they sound the same with or without fill. that's how i came to the assumption that they need more.the port is dead center of a cutout in the middle of the back of the box. thanks for the help

[PWR RYD]

Re: bracing volume difference

Based on the math you have less than a 3% difference in net volume between the two different enclosures. That's not really too much.

Just stab in the dark... could it be that the older ones have been playing for a while (broken in drivers) and the newer ones still have factory fresh stiff spiders? Or maybe the older drivers and newer drivers are from a different batch run and have significantly different T/S parameters?

[kanemack]

Re: bracing volume difference

Based on the math you have less than a 3% difference in net volume between the two different enclosures. That's not really too much.

Just stab in the dark... could it be that the older ones have been playing for a while (broken in drivers) and the newer ones still have factory fresh stiff spiders? Or maybe the older drivers and newer drivers are from a different batch run and have significantly different T/S parameters?

thought about age also. it is a possibility. the first set was given to me new for helping mike220 build his tarkus cabs. they have the super sticky tweeter. the new ones i ordered, the tweet does not draw as mush dust. so it's not outside the realm that the drivers are different. as far as burn in, unless they are known for extremely long time frames, they both have a good deal of hours on them. over 50 at least.

[Paul K.]

Re: bracing volume difference

In my many modelings of ML-TLs, I've found that a difference in cabinet volume, either larger or smaller, of up to 5% is essentially negligible in terms of affecting bass response (F3, for instance).
Paul

[kanemack]

Re: bracing volume difference

checked the impedance all right where they should be.

[GTPlus]

Re: bracing volume difference

Maybe a drawing of the braces/enclosure might help. Is it possible the round cutouts on your braces are too small?

[djg]

Re: bracing volume difference

Swap the drivers you like with the ones you don't. That should tell you what you need to know. If your "fancy" bracing restricts the airflow from woofers to the center port it could affect the sound. There are 3 different 5 1/4" classic speakers, one is a pincushion frame so that shouldn't be a problem, there are 4 and 8 ohm variations. I know you said resistance is the same, just mentioning it.

[PWR RYD]

Re: bracing volume difference

That's a great idea djg. That way you will know if it's the drivers or enclosure.

[djg]

Re: bracing volume difference

Everything I know about speaker building I learned here.

[Mike220]

Re: bracing volume difference

The tritrix I donated were all new. I might have used them to verify fitment but thats it. So they should all have been new. You did mention they had some "updates" hopefully nothing else internally changed. Did you do the AA battery test to verify both speakers move the same direction? Here is a pic of the one you helped me with.

[kanemack]

Re: bracing volume difference

it's not your fault mike you just gave me an older version it looks like. i swapped the CC drivers to the right channel, and it was just louder. bass wise anyways. when i get a decent amp setup i will be able to attenuate the CC. they are still spectacular speakers. i added about 4 ozs more fill. it seems to help, but still gotta mess with it. could all be in my head. have you fired up all 7 at once yet?

[joeybutts]

Re: bracing volume difference

didn't think about that mike.....maybe woofers are out of phase.

[kanemack]

Re: bracing volume difference

didn't think about that mike.....maybe woofers are out of phase.

has it ever happened with dayton before? what i mean is two identical woofers wired backwards?