BetsyK ML-TL and TQWT

[nesha]

I was terrible lazy and innert, and instead of apology let's go on with projects...
I had the same thread in diyaudio.rs , and ZM and couple of friends moddeled ML-TL, and TQWT for me. Strangely , wifey voted for toller and bigger ML-TL...

 

[nesha]

So,question is : can I change (slightly) depth of the box , provided top and bottom remains the same (sq in)?

 

[pjanda1]

That is a nice looking alignment! Given that the line is tapered, changing the depth will change the expansion a bit, if I'm not mistaken. But assuming the change isn't huge, I don't expect that it would make a big difference in the response. Maybe somebody that knows more will chime in. Also, you may have it all planned out, but given the width, a little bracing would be a good idea.

I really like the look of that cabinet. I'm personally amused by how similar the dimensions are to my current open baffle setup! I look forward to seeing your build!

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

 

[nesha]

A friend also did some mesurement (with 'fresh", unbroken-in driver) and this is the result, litle different from published specc. Great guys on diyaudio.rs made tqwt project, with new speccifications. I've been told that mesured Fs would eventualy go down with beaking-in ... Mabye other parameters would change?

Vas test completed: Tue Jul 13 14:10:33 2010
Vas drive current 2393.92 uA
B k, 3 novcica
;------------------------------------------------------------------
Revc = 5.8235 ohms
Fms = 58.1394 Hz
Zmax = 34.8162 ohms
Qes = 0.6529
Qms = 3.2507
Qts = 0.5437
Le = 0.4044 mH (at 1 kHz)
Diam = 165.0000 mm ( 6.4961 in )
Sd =21382.4660 mm^2( 33.1429 in^2)
Vas = 48.9494 L ( 1.7286 ft^3)
BL = 5.6918 N/A
Mms = 9.9433 g
Cms = 753.6449 uM/N
Kms = 1326.8848 N/M
Rms = 1.1174 R mechanical
Efficiency = 1.3844 %
Sensitivity= 93.4305 dB @1W/1m
Sensitivity= 94.8095 dB @2.83Vrms/1m
;------------------------------------------------------------------
; When testing drivers with an up/down radiation (cone motion)
; enough weight should be used to get a decent resonance change
; without significantly altering the drivers suspension zero point.
; A typically good configuration is when Fs/Fsa=1.25.
; Horizontally mounted drivers are less susceptable but require
; a clay or soft caulk mass. The following may be of help
;------------------------------------------------------------------
Fms= 58.1394 Mms = 9.9433 g
Fsa= 38.2079 Mms+Ma= 23.0233 g
Fs/Fsa = 1.5217
Ideal Test Mass = 5.5931 g
Test Mass used = 13.0800 g
Missed ideal by = 7.4869 g (too heavy)
Nickels used = 2.6160
;--- Impedance Fitting Constants ---
Krm 977.166E-06 ohms Freq dependent resistance
Erm 814.437E-03 Rem=Krm*(2*pi*f)^Erm
Kxm 14.118E-03 Henries Freq dependent reactance
Exm 616.299E-03 Xem=Kxm*(2*pi*f)^Exm, Lem=Kxm*(2*pi*f)^(Exm-1)

 

[pjanda1]

A friend also did some mesurement (with 'fresh", unbroken-in driver) and this is the result, litle different from published specc. Great guys on diyaudio.rs made tqwt project, with new speccifications. I've been told that mesured Fs would eventualy go down with beaking-in ... Mabye other parameters would change?

Yup, VAS should go up, Qts down. I don't know that it'll make a giant difference to the box tuning, but were I you, I'd model with the published specs before cutting wood. Or, break them in with some low frequency sine waves (don't break them, of course) and remeasure. For most of us that don't build a box a week, its good to get them right!

Looking good though. We're you originally thinking Onken? These are going to be much easier to move!

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

 

[nesha]

Thaks PJ. I've got tqwt simm with published spec as well, slightly bigger.Compact and nice,I thought, but my better half sead nope, go for pyramide...

 

[nesha]

I finaly started cutting and glueing.One side panel will stay unglued for change in damping of the box, and in few months, I'll glue 10mm plywood
from outside, for aestetics an dampening of the panels.

 

[pjanda1]

Those look great!

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

 

[nesha]

And - ... it works! The box is glued with Titebond, one side panel just screwed, inside few sheets of sponge (temporarely, till I get syntetic wool) ... but - it works!!! I mean, there is bass, without any filter. My room is 5x4m (15x12ft), and boxes are about 1 foot from the wall, and 2m between them. I'm pleased with sound, there is no rough peaks, Wild Burro BetsyK is easely better than my old Heybrook HB1. I'll post more pistures ind listening impressions. I'm thinking now what wire to use and how to finish boxes.

 

[nesha]

Sorry about bad pictures , I don't have camera right now, an I'll post some "proper" pictures soon...

 

[nesha]

Legs (distance from the floor) are 10cm (4") , an I'll try 15 or 20 cm , for more clear bass...

 

[nesha]

Start amount of wool, 200gr/box

 

[nesha]

He, he..I had a visite yesterday, a friend who's been listening B&W CDM2 monitors for last 10 years. We listened K Melua and M Gardot, and his comment was - This is so much better than my speakers, smooth but goes deeper into the recording...-
But we did hear a boomy bass sometimes... Lazy that I am, haven't tried taller legs...

 

[pjanda1]

Nesha,

That's great! Getting boxes and rooms to get along can be tough. You might try experimenting with placement in addition to legs, and/or it could be that you need to alter the stuffing. Often it is all just a matter of experimenting until you get it right. I'm glad you are enjoying them so much overall!

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

 

[nesha]

Yam-yam!

 

[glt]

Port

This looks like an easy enclosure to build. Does the port run along the width of the cabinet?
Thanks....

 

[nesha]

Port is round, simple circle onthe bottom, 8" (20cm) in diameter.I'm sorry I haven't built them with BBplywood in the first place...

 

[nesha]

Ups, my mistake, port is 24 cm diameter, as on diagram.