Hi I broke my ankle and dislocated my foot so I am down for at least 10 weeks. so I am trying to figure out how to plan my next speaker. I want to downsize the excellent small thors. I already have switched to the nextel drivers and with a lot of help got them working pretty well in the old boxes. I rarely listen to them as they are downstairs and I really want to move the music party upstairs. So this is an opportunity to design and build the boxes. Attempt to mimic the small thor design making it smaller sacrificing bass. I would like to stay with the mltl style but there is very little information on how to do that. the fs is 40 on the woofers and the quarter wave would be just over 84 inches. the thors have a fs of 34 so they need 102 inches so I am pretty sure this will not work but can I change the length of the speaker by 83%? At this time here is my plan
design and build the boxes
use the current crossovers and measure
replace the parts in the crossover to get a slightly decreasing fr.
put is all together and live in musical bliss. here is a rough drawing of my plan for the boxes.
design and build the boxes
use the current crossovers and measure
replace the parts in the crossover to get a slightly decreasing fr.
put is all together and live in musical bliss. here is a rough drawing of my plan for the boxes.
Attachments
8ntractor,
Sorry to hear about your accident. Wish you a smooth recovery, and may you have lots of fun planning the next speaker project, and then building it when you're back on your feet again!
Sorry to hear about your accident. Wish you a smooth recovery, and may you have lots of fun planning the next speaker project, and then building it when you're back on your feet again!
If the Thors midwoofers have an fs of 40 Hz, a line length of 102" would only be correct if their Qts was equal or close to 0.40 (with the effects on Qts of resistance in series with them, like from a crossover inductor taken into account). Also, if the line has a negative taper, its actual length will be shorter. For instance, if the line is tapered at 10:1, the line's physical length would need to be only ~60" long for its effective length to be 102" long and have a 1/4-wavelength resonant frequency of 40 Hz.
Paul
Paul
Hi thank you for the well wishes things happen in fast.
pkitt - the thors have a fs of 34. I had to replace them with non magnesium cone and now have the nextels which have a fs of 40. sorry I did not explain myself well. the small thors are a straight line. I will add a drawing of the small thors. for clarity I am changing the woofers to the w18nx001 from the w18e001. Here is also the data sheet for the woofers I will be using.
pkitt - the thors have a fs of 34. I had to replace them with non magnesium cone and now have the nextels which have a fs of 40. sorry I did not explain myself well. the small thors are a straight line. I will add a drawing of the small thors. for clarity I am changing the woofers to the w18nx001 from the w18e001. Here is also the data sheet for the woofers I will be using.
So I looked at Zaphs website and the free air resonance for the w18nx001as measured is 46 of which a 1/4 wave 34.6 inches which would equate to 72% of the small thor size. So a 35" tall cabinet. There is just not much info but it looks like the drivers need to be placed 1/4 of the way from the top of the line? so that would put the drivers at about 26"
I found the least confusing calculation for t lines so far
Mysteries of TL Design
I found the least confusing calculation for t lines so far
Mysteries of TL Design
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It's a moderately forced mass-loaded quarter-wave so the physical length of the enclosure / longitudinal eigenmode does not correspond to the QW length of a simple open-ended pipe, and is not a fixed percentage thereof. MLTLs / MLQWs can vary somewhat in proportions depending on design goal and the amount of forcing applied.
Thank you Scottmoose, I had only a small hope that doing a ratio based on fs would work. I guess if I build a internal 6.5 x 38.5 x11 with a holey braces like the small thor the worst that could happen is I will have a well braced ported cabinet. The small thor was the best sounding speaker I ever owned. Even when I put the nextel f46 drivers in the small thor the bass in room was in the low 30s I would be happy to replicate the same quality of sound with less base.
I read an article called alpha transmission line speakers but it is focused on stuffing integrated in the calculations and Martin King has said that the stuffing impact has been misinterpreted in a different article I read. Is there reference material for forced mass -loaded quarter-wave calculations? Bailey seems to be dated.
I read an article called alpha transmission line speakers but it is focused on stuffing integrated in the calculations and Martin King has said that the stuffing impact has been misinterpreted in a different article I read. Is there reference material for forced mass -loaded quarter-wave calculations? Bailey seems to be dated.
Off topic, but when you have a cast on your foot, it might twist your foot when you sleep on your back. So care might be wise to avoid that. Just not nice to walk after recovery with one foot slightly twisted! Myofascial trigger point therapy helps if you can find such a therapist.
Simon7000 I thought I had to sleep on my back very difficult to do for me anyway as I am normally a side sleeper. I was able to get a little sleep last night but am not getting much. It is actually my first broken bone so I am not sure what to expect. I had surgery last thursday so almost a week. I will try side sleeping tonight as that would help me sleep greatly. When they relocated my foot the doctor said ankles are hard to get correct unlike a shoulder or knee there is no socket to fall into. Ironically 2 weeks before I broke it we bought a treadmill and running shoes. I guess I was meant to be 60 lbs overweight.
FWIW, with several different hip/knee/ankle/foot injuries I slept seated ~upright propped up', braced' in the corner of a 'love seat' with king size pillows.
Thank you GM I have my foot and head up but I seem to be a creature of habit and unless I am really tired sleeping in a chair or even just on my back is difficult.
Dont do what I did after a broken arm.
I started doing bits of electronic bench work fairly soon after the break.
After 2 months I thought I would be ok so had a go at driving the car and the arm snapped again.
I started doing bits of electronic bench work fairly soon after the break.
After 2 months I thought I would be ok so had a go at driving the car and the arm snapped again.
Thats terrible. thank you for the advice It has been 12 days since the break I am having a hard time with 10 weeks off my foot but I am sure that if I am my usual self and hurry it a bad result will happen. I just have to not think about all the things I had planed to get done.
It does require good lumbar, neck support with head ideally tilted slightly down, not to mention a very 'cushy' seat cushion.
Regardless, hope you mend well with no [long term] complications! Mine are all long ago now, but recently they've been 'coming home to roost' now that old age is wasting away good bones in between, forcing bracing whatever limb
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