Round over bit to make an aeroport flared?

[Quentin Jarrell 671]

Port compression is completely different than port noise. Minimum port area formula is for port compression.

I have 6th order bandpass on a ten inch driver that does 150 on 1,000 watts but that says nothing about the quality of the sound reproduction being produced.

[skittlesRgood 3]

Port compression is completely different than port noise. Minimum port area formula is for port compression.

I have 6th order bandpass on a ten inch driver that does 150 on 1,000 watts but that says nothing about the quality of the sound reproduction being produced.

ok, I got an 82.75 in MECA SQ with that same box in the car.

[Quentin Jarrell 671]

@150db you didn't.

[supragod98 4]

I would flare it as much as you can.  It does make a difference.  I use a 1.5" round over for anything bigger than 6".

[skittlesRgood 3]

@150db you didn't.

of course not. but it does show that the box performed well under both criteria. you seemed to want something measurable on the "quality of the sound" so now I've provided my numbers for SPL and SQ with the same box and still stand by two 6" aero ports as being enough. I'd never go so small with a slot port, but aeros are different. if you believe differently then post results on a box you made with two 6" aeros for a pair of 12"s that didn't perform well.

 

But you do point out one beliefe of mine: that it's stupid to think about SQ at SPL volumes.

Edited August 30, 2013 by SkittlesRgood

[EPerez 236]

Does anyone know how much the x 12s need at 29hz? I got around 90 at 17 m/s port Mach speed.

I don't see why 2 6" aeros wouldn't work. Jacob was using 1 6" with the z v.4. Also I see people doing great with 1 8".

[S.DeYoung 967]

What do you consider doing great?

[S.DeYoung 967]

Doing the formula, recommended minimum is an 11" round port

[S.DeYoung 967]

http://www.carstereo.com/help/Articles.cfm?id=21

[Quentin Jarrell 671]

Doing the formula, recommended minimum is an 11" round port

The definition for xmax is coil overhang, not the typical 70% BL figure posted.

[S.DeYoung 967]

Doing the formula, recommended minimum is an 11" round port

The definition for xmax is coil overhang, not the typical 70% BL figure posted.

Yes I know that, isn't posted xmax 30?

[Quentin Jarrell 671]

If posted xmax is 30, then depending on the strength of the stray flux field, coil overhang would be 20mm give or take a couple mm

[S.DeYoung 967]

If posted xmax is 30, then depending on the strength of the stray flux field, coil overhang would be 20mm give or take a couple mm

 

Very good information Quentin, thank you.

[EPerez 236]

By doing great, I mean by numbers. They put up good numbers with the size ports I would use.

Edited August 30, 2013 by Bassink

[Quentin Jarrell 671]

.

Edited August 30, 2013 by Quentin Jarrell

[EPerez 236]

Quentin, if the coil overhang is around ~20 then it would need a lot less port area then what we thought right?

http://www.carstereo.com/help/Articles.cfm?id=31

I used this and put in 2 for amount of subs, 22 for xmax, and 29 for tuning and it came out to 9.43" diameter or 69in2 of port area. Why is that so low??

[Quentin Jarrell 671]

Well there you go. Now you see why Jacob has success with a 6 inch port.

The problem people are having is they do not have a basic understanding of what they are doing.

I have said it time and time again. The loudspeaker cookbook is a tiny fraction of the amount of money people spend on their product.

[EPerez 236]

I'm definitely going to buy that book. Thanks Quentin.