Surround Speakers

[Higo]

Hello,
I finished to design my surrond speakers and I appreciated if some of You give me your opinnion:

2 Way system in sealed box:

-MiddWoofer: 6" Made in Argentina with:
Qms 2.29 / Qes 0.73 /Qts 0.55 /Vas 4.23
-Tweeter: Audax AW010E1

Box volume 8 lt (MDF of 9mm 19x31x17 (WxHxD) with a 3mm MDF with finish foil in cedar colour.
Better than fiber glass..acustic foam...www. sonoflex.com
I `ll use 35mm with the following coefficient of sound absoption:
125Hz ----0.1
250Hz-----0.19
500Hz-----0.39
1K----------0.82
2K----------0.97
NRC 0.59 (what`s this? )

XOP:
-Low pass: first order fc=6Khz, L=172uHy
-Zobel net :R= 8.2 ohms and C= 5.6uF
-High pass: Second order fc=6khz, L=120UHy asnd C=3.3uF

Any comments?

Thanks,
Marcelo

 

[7V]

"There is no emotion; there is peace.There is no ignorance; there is knowledge.There is no passion; there is serenity.There is no death; there is the Force."

I won't comment on your 2-way except to wish you luck with it. Other members are better qualified than I am on that one.

I just had to say, reading your signature quote, you haven't been on the forum recently, have you?

 

[Higo]

Not. The true is that I`m member since last year but I posted a little.. . I just married, bought a house, well a lot of things... I didn`t too much free time..
Why the question? Is it not allow SW frases ?
Marcelo

 

[faustian bargin]

i think 7v was tongue-in-cheekily referring to the apparent lack of peace, knowledge, serenity, and in general 'Force', present in the forums of late.

although everyone knows the Force has both dark and light sides...like a halibut. ('duct tape' is so passé.)

/andrew

 

[7V]

I was just kidding. In reality this is the most helpful and friendliest forum I've found.

Now is someone going to look into Marcelo's surround speakers or what?

 

[pinkmouse]

Hi Higo

Is there a reason for the crossover point being so high? Most 6" drivers will be getting fairly directional by that point, and you might also have problems with lobing with the tweeter.

 

[purplepeople]

As these are surround speakers and need to be directional, I can understand why you're XO at 6 KHz, especially since the mix is done in a studio with special attention paid to the directionality of surround sounds.

But, how will the LF driver handle the freq from 3 to 6 KHz? If it cannot do this well, should you then consider using a 4" LF driver instead?

To correlate with postings in another thread, you seem to be XO at freq that are higher than most factory made speakers, never mind other DIYs. I don't understand, are the tweeters not capable of lower?

ensen.

 

[Higo]

Thanks fot your comments, guys.

Jensen: Unfortunatly my country is not a good market in tweeter area. I mean you can not find good tweeters. I think that I was lucky when I found these Audax. Anyway if you look into the data sheet of Audax you see that they recommended fc at 5khz.. if you need 50w and I have a 80W amplifier .
I measure the frecuency response of the mid woofer and It has good response beetween 3-5K. Then start some kind of ripple...
Marcelo

 

[Higo]

Have you been using acustic foam in your proyects, like I posted? I`m not pretty sure about the amount that I have to use. I know, that It`s reccomendable to leave one of the faces without over (standing wave problem). Is It right?
Marcelo

 

[pinkmouse]

I measure the frecuency response of the mid woofer and It has good response beetween 3-5K. Then start some kind of ripple...

Marcelo

If your driver's response curve starts getting lumpy at 5k then you will need to roll off it's response a lot lower, or use a very high order crossover, or these ripples will come through in the final box response curve.

As for the foam question, some people say that a box can be overdamped if damping is put on every wall. I personally have never had this problem, but it's something you can tweak when the boxes are finished. I wouldn't worry about it for now, just get as much as you need, and any extra left over at the end could be saved for another project.