Paradox in HIVI M4N's Qts.

[bigcatdairy]

Ladies(if there is any & Gentlemen:

I've got a pair of HIVI M4N and wanna build a pair of sealed box, but when i input the parameters into winISD then I've got a 121l of box volume, it seemed something wrong, I input the params into a web calculator, I got negative box volume, is there anybody can tell me why?

BTW: I think those results were caused by the Qts which as 1.08, is it wright? what can I do for calculate the correct box volume?

Any feedback will be great appreciated, thanks for reading.

FYI:
HIVI M4N: http://www.hiviresearch.com/driver/h...st.php?type=11
Web cauculator which gave me negative box volume(not the calculator's fault): Speaker Box Calculations

[sreten]

Hi,

You will get a negative box volume if driver Qts is higher that the box Q target.
with a Vas of ~ 4.5L your looking at a sealed box around 6L or some pretty
wacky vented alignments up to 9L.
Typical calculators go for Qbox of 0.7, your looking at =1.4 6L, =1.3 9L.
TBH there not a lot of real difference between the two, both bass peak.

6L sealed gives you a 3 dB hump around 100Hz. 9L vented at 50Hz gives
loads more bass and will probably works best as a power handling alignment
combined with the 80Hz setting of an AV amplifier (small).

Without AV a bass bump can compensate for no bass lower down.

rgds, sreten.

[bigcatdairy]

HI Sreten:

Originally Posted by sreten

Hi,

You will get a negative box volume if driver Qts is higher that the box Q target.
with a Vas of ~ 4.5L your looking at a sealed box around 6L or some pretty
wacky vented alignments up to 9L.
Typical calculators go for Qbox of 0.7, your looking at =1.4 6L, =1.3 9L.
TBH there not a lot of real difference between the two, both bass peak.

for here understood, so can i ask you what sounds different for a speaker system at a 0.7 and 1.x in Qtc?

And here can i do anything to reduce the Qtc down to 0.7 for the enclosure?
Wht the manufacturer design those drivers on such a high Qts? What's the advantage of such a high Q drivers?

Originally Posted by sreten

6L sealed gives you a 3 dB hump around 100Hz. 9L vented at 50Hz gives
loads more bass and will probably works best as a power handling alignment
combined with the 80Hz setting of an AV amplifier (small).

Without AV a bass bump can compensate for no bass lower down.

rgds, sreten.

Unfortunately i don't have any AV amp, i drive my bookshelves on a DIY LM1875 amp.

Thank you very much for your reply

[sreten]

Hi,

The easiest way of making a high Q driver is taking a decent driver
and fitting it with an undersized magnet, its cheap and cheerful.

I suspect the driver is developed for HT systems.
Used as a mid only the bass peak would be less troublesome.

The B4N seems a decent driver, but needs a clever crossover :
https://sites.google.com/site/undefi...ightsensations

One approach would be undersize your amplifiers input capacitor,
set it for 100Hz, i.e. -3dB at 100Hz. This would combine with
the driver to be flat to 100Hz, and then a 3rd order roll-off
below that, but you ideally need a sub for real bass.

rgds, sreten,

[bigcatdairy]

Hi Sreten:

please tell me undersize to what criteria? undersize to the suggested 5l box? or what?

and the like you quoted was unreachable here, was it hivi b4n?

thanks.

[sreten]

Hi,

At Parte Express the B4N is the same price as the M4N and seems in all respects
a better choice than the M4N, especially regarding published designs for it.

Compare the weights of the 2 drivers, the M4N must have smaller fitted magnets.

The tricky c/o used on the B4N implies something similar is needed for the M4N.

M4N : http://www.parts-express.com/pdf/297-434.pdf

TBH if building something I'd bite the bullet and go for the B4N, lower Fs,
lower Qts, higher sensitivity (+ 3dB) all add up to a much better driver.

Both drivers need clever work in the crossover to work properly.

rgds, sreten.

[bigcatdairy]

Sreten:

Thank you very much for your advise, I'll try accordingly.
have a nice weekend.

[bigcatdairy]

Sreten:

Thank you very much for your advise, I'll try accordingly.
have a nice weekend.

[sreten]

Hi,

I have to repost : https://sites.google.com/site/undefi...ightsensations

Lots of information ; Lots of options ; Great $24 cabinet options ; You can't go wrong.

Even on PE there are loads more actually useful files on the B4N for rolling your own.

The c/o is so tricky for both IMO you might as well give up on the M4N, go for the B4N.

In terms of time, effort, confusion and being happy I highly recommend this action.

rgds, sreten.