Mark's proto 6.5" Woofer, 1" silk Tweet combo

[markaudio]

Hi H,
I've got a series of projects in progress (too many really). Here's pics of Tweeter No 1 and woofer No 10. For the woofs I'm sort of going on size, No.6 is 6", No 10 is 10"(25-cm) and so on but naming is not fixed as yet.

Cheers

Mark

[markaudio]

Hi PeteMcK,
Thanks for your input. Along with some direct email feedback, the thinking is the Total Q of the 6.5" woof is too high. For guys wanting large sealed boxes (60 litres up) it's potentially a nice driver. But for most applications, the larger box volumes aren't practical.

Suggestions I'm getting are in the region of 0.4 to 0.6 for the Qts. This should allow the driver to operate more effectively in vented or sealed volumes in the range of 14 to 30 litres.

Please feel free to feedback on parameters. This is the time when I change the design of the components and do some tweaking. The challenge is to make changes without adding cost........ummmmmph.

Cheers,

Mark.

[human.bin]

wow, that blue is so nice

[markaudio]

More work on the Woofer. After some tweaking, here's the latest set of parameters. Briefly, Qts is reduced to 0.37. Resonance frequency is lowered to 40-Hz, Vas is up to +30 litres. SPL is also increased to 88dB. This should make the driver more practical for most box designs.

I only had 4 Ohm coils in stock so hope to wind a 6 Ohm unit next week.

Comments appreciated

Revc= 3.600 Ohm
Fo= 39.534 Hz
Sd= 12.868K mm
Vas= 30.033 Ltr
Cms= 1.277 mm/N
Mmd= 11.849 g
Mms= 12.688 g
BL= 4.960 T
Qms= 1.818
Qes= 0.461
Qts= 0.368
Levc= 223.069u H
No= 0.400 %
SPLo= 87.919 dB

Cheers,

Mark.

[markaudio]

Hi Guys,
The woofer's performance has been revised, see details on this thread:

Mark's proto 6.5" Woofer, 1" silk Tweet combo

suggestions and comments appreciated.

Thanks

Mark.

[gooki]

The drivers have a lot of potential if you can get the prices right (i.e. low).

I'm always on the look out for a low cost woofer tweeter combo to recommend to friends who want to get into DIY, but don't want to spend a lot on raw driver and then screw it up. And at the same time want something of quality that will work with various crossover and enclosure designs.

PS I'm not a fan of the cone/dustcap colour vatiation. I'd personally prefer all black cones or possibly your trademark copper/gold colour (which works well contrasted to a black tweeter).

[event horizon]

Originally Posted by markaudio

suggestions and comments appreciated.

Total Q has been designed to be high to assist in LF delivery, especially in BR boxes.

QTS 0.823

Hi Mark, isn't that total Q rather high for a bass reflex? Sorry, i'm assuming that's what you mean by "BR" box. Only reason i ask is that in effect the amplifier needs more control over the cone than it would in a sealed box (where the box can help control the cone motion).

You have gotten me interested as i happen to have some (what i regard as high Q) bass drivers that are of a similar Q to yours. Admittedly these haven't been run in so the Q may lower & VAS increase, however they are still a nightmare in a reflex enclosure

Transient response suffers & damping from the amplifier is less than with a low QTS driver, i'd expect the things (mine) to have a rather boomy & uncontrolled bass.

Perhaps i'm missing something? Please feel free to fill me in & this post is in no way meant to p*ss on your fire so to speak

Another Mark.

[markaudio]

Hi Mark (another),
How's like in UK?
Many thanks for your suggestions. Agreed, I over cooked the Qts in the first proto. Thinking guys like to build big boxes but times are changing. Did you the end of the thread? I've changed the driver's damping and coil to get these results:

Revc= 3.600 Ohm
Fo= 39.534 Hz
Sd= 12.868K mm
Vas= 30.033 Ltr
Cms= 1.277 mm/N
Mmd= 11.849 g
Mms= 12.688 g
BL= 4.960 T
Qms= 1.818
Qes= 0.461
Qts= 0.368
Levc= 223.069u H
No= 0.400 %
SPLo= 87.919 dB

Might be interesting to produce two driver types - high Q for those who want to make a large classic sealed, lower Q for BR's and alike. Ummmmph...... will be be enough demand for both types?

Cheers,

Mark (HK)

[markaudio]

Hi Gooki,
Thanks for comments. Agreed, my thinking also. Basically, I'm attempting to make:

1 - a low cost woof-tweet combination
2 - with a wide near flat combined frequency range
3 - easy to design a cross
4 - and various box type friendly

I know there's allot of drivers out there but I'd lke to have a go because many guys know me for my work on full range. I enjoy tweaking drivers to extract extra performance.

Re cone colours, I'm thinking of offering 2 colour choices, including an all-black cone/cap.

Cheers,

Mark.

[DcibeL]

This looks quite interesting. I understand that the tweeter is to come in around USD$10, do you have an expected price (or range) for the woofer?

I really like the look of the woofer, apart from the frame, specifically where the frame meets the driver surround. This ends up not looking very attractive when mounting the driver on the front of the baffle, and I'm not really a fan of mounting on the back side of the baffle, but if the price is right it may be a worthwhile compromise.