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

[markaudio]

Hi DecibeL

Yep, the tweet should sell around the US$10. The woof should sell under US$30. I reasonably confident of achieving this. I'm still tweaking so there's always a compromise to be made on price V performance.

I'm supplying black coated Hex head screws that look quite nice with this frame. I'd like to use this frame as its well designed for the price. 6 screws will give a more "built" look when mounting on the front of the baffle. The rear of the frame is vented which helps me lower the cost on the rear suspension with no compromise on the performance of this component.

Cheers,

Mark

[gfiandy]

Hi, looks like a very interesting driver set for DIY projects on a budget. Is it at all possible to lower the Fs of the tweeter to make it easier to use a series cap as a xover.

Regards,
Andrew

[markaudio]

Hi Gf,
Many thanks for your suggestion but difficult to do for the price. I'll have to give up some of the extended high range to do what you ask. There's allot of tweets in this price range operating around 1500 to 20-kHz, whereas my No.3 tweet is good to 30-kHz. The extra 10-kHz may be worth keeping in this budget tweet.

The cross range is 2 to 5-kHz, a wide choice. I am working on another tweeter with an Fo of 650-Hz but it won't be budget.

Thanks
Mark.

[gooki]

I tend to agree with DcibeL on the frame comments.

If the target is people getting into DIY not the long term DIYers, they'll be less likely to be prepared to go to the effort of mounting the driver from the back of the baffle.

However I'm not sure if a more ascetically appealing frame is do-able within the price range. Your suggest price range is a good target.

PS the tweeter mold/mount looks suitably swank.

And since I'm commenting on your speakers Mark, I'd like to say my initial impressions on your Alpair 5's is they're a nice upgrade over the stock drivers in the Morel Soundspot speakers.

[J.R.Freeman]

Hi Mark,

Great work! Those look like impressive drivers. I am particularly impressed with the smoothness of the impedance plots for both, and the HF extension of your tweeter. The white cone of the woofer is nice - you don't see too many these days. It kind of reminds me of a studio monitor mid-bass.

I must say I am impressed that you trade ideas so openly with prospective customers. Having been interested in loudspeakers for years and years now, it's interesting to get a glimpse into the design process of actual drivers! As an aside, your website looks great. For those of you who haven't taken a look it can be found here: http://www.markaudio.com/

Keep up the good work,

Jim

[markaudio]

I understand having some reservations about this style of frame.

The reason this frame caught my eye was its looks and versatility. Its got a nice powder coat finish. Its easy to front mount and/or recess into the front of the baffle. The lip is wide and flat making it easy to seal. Using some nice black or silver Hex head screws gives a nice look.

Technically, its a reasonable frame to work with. The vents behind the spider mount help with the selection of damping material. I can fully align and tightly secure the magnet system to this frame (many cheap frames can be an alignment/mounting pain during assembly...urrrrrgh!).

Overall, I think this frame offer allot of choice and an easy fit.

Cheers,

Mark.

[markaudio]

Thanks Gooki for your comments on the Alpair 5. Glad they are working well.

Here's a pic of the latest sample set of tweets.

Mark.

[event horizon]

Originally Posted by 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

Hi Mark, things aren't too bad here in the UK - well for me at least I just wish my back wasn't messed up, but i've been living with it like this for nearly 20 years so i should be used to it

The new specs look vastly better for a bass reflex enclosure Improved efficiency & an almost ideal total Q to get a nice flat response, which i should imagine would extend to the drivers resonant frequency. I haven't run it through WinISD but i should hazard a guess & say it should work nicely down to about 40Hz.

Nicely done that man! I'd have thought that this driver spec would be a more popular buy that the earlier version tbh

All the best

Mark.

[gfiandy]

Hi Mark,

Thanks for the reply, its kind of what I expected, if you could have done it you would have. But if you don't ask!

Personally I would rather have 1K - 20K over 1.5K to 30K however I realise many people belive the extra 10K at the top is more significant.

Regards,
Andrew

[markaudio]

Hi Mark (another)
Hope you're back improves as best it can. I know the feeling, I injured my lower back some years ago so I manage by regular trips to the gym for stretching.

Thanks for your comments. I'm still in need of taking the time to tweak further. The new specs are encouraging but the down-side of softer mechanical damping is power-handling. I'm currently running a 100 hour power test and think the driver won't make it all the way through the run. If this is the case and we get a failure in either suspension, then I'll have to re-work the design. No free lunch when it comes to designing drivers sadly.

Cheers,

Mark.