I am currently building this same box. I have escewed internal bracing for 2 reasons- to save weight, and it's too hard/complex for me. B/C of my situation I will have to slide them around regularly. The owner at Madisound talked me out out of the treble attenuator sold by Seas for the F8. I guess Seas made the x-over ( treble killer) because so many people complained(?). I have a question about batting. Trol Graven said he used 15gr/liter of batting, the box is 60 liters so using advanced econometrics I came up with 2 lbs of batting per box!? Really? I am using real wool batting, soo much better that that cheap polyester stuff, maybe. So how much batting did you use. If you already wrote it in the dialogue sorry to not have read it. I am using 3/4" Baltic Birch which is actually 19mm which caused slight adjustments for the guy building them for me. I am using what I call frame bracing. All edges get 1 1/4 inch dowling. How about internal wiring. I intend to use single strand pure silver wire. Also single strand pure silver soeaker wire. I am taking my cue from Gaincard owners single strand copper wire. Also in addition to the batting I intend to line all internal sides with 100% 1/4" wool felt b/c I see Phy HP use it in their speaker design. Finally Tried & True varnish for finish, though Danish Oil looks good on the samples I made.
joh-fosse I'm pleased to hear you are building the SEAS speaker and hope you will be delighted with them. I did use double thickness front and back panels, and add some varied material and deflex pads to the sides. Internal volume is a little over 60L. I added a good inch of polyester fibre wadding round the sides and to the baffles. I did not want it too heavily damped. I feel that the bass performance is very good. As for the rising frequency response, I haven’t used the external L/R/C circuits since I built the switchable circuit described above. The speaker terminals on the back are on removable airtight mini-panels so I could take them out and change the wiring if desired.
I am surprised by your complex pursuit of frequency manipulation in the widebander design. I thought the whole point was to get a pure unadulterated signal from the amp to the speaker. Are you using tube amps? I note that my German Rike Class A2 has much nicer less screechy treble compared to my Job/Goldmund amp. When I read Six Moons on the issue of widebanders I note that Ebaen shows that all the wide bander makers, Eg Zu, all end up adding a sub & treble which seems to make the issue of widebander mute. So I do understand your pursuit in making the F8 actually work for you as a single standalone speaker. I would be grateful to know what freq attenuation you end up with so can try it. Like I posted before, Seas actually sells what looks like a really basic treble rolloff board for pretty cheap.
I screwed up. New posted mistake. Sorry. Re batting. yes, 2 lbs sounds like too much, one pound sounds more reasonable to me. I thought batting was suppose to be loose fluffy stuffing, but main thread guy says he lined his box with batting. My wool batting actually comes almost like the wool felt, but I have been teasing it apart and using it as fluffy stuffing. I have to admit that I really have no idea how batting changes bass response. Honestly I don't understand why alot of this stuff works. Thank goodness for the goodwill of the community and my enjoyment of reading.
I use very clean tube and SS amps. LTA, SX class A, and KT150 SET. None introduce any harshness. The speaker is connected directly to the output of the amplifier. The control box goes between the DAC and the input of the amp, it does not cause any audible degradation, but it is very useful as a variable treble cut. I switch it to a greater cut if a recording is too bright or poorly recorded. Good quality recordings sound particularly awesome!
BTW have you seen this opinion, https://www.tnt-audio.com/casse/seas_exotic_e.html
regards
BTW have you seen this opinion, https://www.tnt-audio.com/casse/seas_exotic_e.html
regards
Now I enjoy this SEAS build on a daily basis and enjoy making things as much as using them, so I am curious to hear how they would sound in another type of enclosure. What I have in mind is what seems to be called a mass loaded tapered quarter wave pipe. (ML-TQWP).
I have read up what I can find so far but do not have any simulation software for them apart from the simple online calculators.
As mentioned my den is a small room so high power and very low notes are not needed.
Using mh-audio.nl calculator with SEAS data; Fs 32Hz, cone area 222 cm², Qts 0.44, suggests a folded design 132H x 25.3W x 37D (cm) with a line length of 259 cm. port tuned to 32Hz.
This would be a bit taller than I had in mind and I sketched a possible starting point which has an estimated L of 206 cm. The pipe starts same area as the cone 222 cm²and expands to 666 cm².
I’d be grateful if anyone knowledgeable on these comment on the soundness or otherwise of this.
I have read up what I can find so far but do not have any simulation software for them apart from the simple online calculators.
As mentioned my den is a small room so high power and very low notes are not needed.
Using mh-audio.nl calculator with SEAS data; Fs 32Hz, cone area 222 cm², Qts 0.44, suggests a folded design 132H x 25.3W x 37D (cm) with a line length of 259 cm. port tuned to 32Hz.
This would be a bit taller than I had in mind and I sketched a possible starting point which has an estimated L of 206 cm. The pipe starts same area as the cone 222 cm²and expands to 666 cm².
I’d be grateful if anyone knowledgeable on these comment on the soundness or otherwise of this.
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That simulator will not do the ML-Voigt you ar elooking to do.
To know what the box does you need a proper modeler. MJK (NLA), HornResp, or this https://www.diyaudio.com/community/threads/transmission-line-modelling-software.220421/
dave
Thank you for pointing me in the right direction. Using hornresp I have simulated a horn with mass loading tube, It looks promising (am I doing something wrong!)
I was wondering if it's useful to attach an elliptical shaped sub baffle to smooth baffle edge effects. I see this on some of the posted designs. Would be grateful for your thoughts.
I was wondering if it's useful to attach an elliptical shaped sub baffle to smooth baffle edge effects. I see this on some of the posted designs. Would be grateful for your thoughts.
There was a mistake in that simulation – I’d forgotten to put in the area of the port. I have since spent hours becoming familiar with hornresp (fun!) simulating various tapers and pipe lengths. Have concluded that a 2m line with suitable damping will give a useful extension of bass while hopefully keeping control of the cone movement.
So now I have a bit of a dilemma. The existing speaker is a great success. I am not particularly in need of changing anything. I small repositioning in the room has given a well-balanced sound. Wondering how much can I improve on it. It is an experiment with some cost and effort to build a new enclosure, and I don’t know how much it will improve the speaker.
So now I have a bit of a dilemma. The existing speaker is a great success. I am not particularly in need of changing anything. I small repositioning in the room has given a well-balanced sound. Wondering how much can I improve on it. It is an experiment with some cost and effort to build a new enclosure, and I don’t know how much it will improve the speaker.
what is the benefit of the sealed half wave resonant line compared to a sealed of the same volume ?
I think people mention standing waves when using a mltl (where basically a long shoe box) ..........
Granted, this is a tapered pipe...............
the tnt article had the f8 in a (seas recommended) sealed driver at top of the pipe (no taper, not middle of a pipe).
https://www.tnt-audio.com/casse/seas_exotic_e.html
http://www.seas.no/images/stories/exotic/pdf_datasheet/f8-appnote.pdf
I think people mention standing waves when using a mltl (where basically a long shoe box) ..........
Granted, this is a tapered pipe...............
the tnt article had the f8 in a (seas recommended) sealed driver at top of the pipe (no taper, not middle of a pipe).
https://www.tnt-audio.com/casse/seas_exotic_e.html
http://www.seas.no/images/stories/exotic/pdf_datasheet/f8-appnote.pdf
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I remember larryldspkr having a (mltl ?) in a 10" x 10" x 44".
"Rear 4 inch vent close to the bottom, internal walls are damped with memory foam mattress pad."
"I don't have a drawing but the inside dims are 10” X 10” X 44” inches, driver is 10 inches down from inside top. Port is 4 inch diameter, 2 inch long centered 5 inches up from inside bottom."
"There is a pipe harmonic at 150hz which I was able to damp out with hollowfill stuffing but after careful listening all the stuffing was removed!"
Well, according to my math, 1129 / [(44” / 12”) x 2] = 153hz
I can see how it is nice to get the drivers higher up off the floor compared to a squat box.
"Rear 4 inch vent close to the bottom, internal walls are damped with memory foam mattress pad."
"I don't have a drawing but the inside dims are 10” X 10” X 44” inches, driver is 10 inches down from inside top. Port is 4 inch diameter, 2 inch long centered 5 inches up from inside bottom."
"There is a pipe harmonic at 150hz which I was able to damp out with hollowfill stuffing but after careful listening all the stuffing was removed!"
Well, according to my math, 1129 / [(44” / 12”) x 2] = 153hz
I can see how it is nice to get the drivers higher up off the floor compared to a squat box.
The current enclosure is 60L sealed built very close to SEAS application note.
http://www.seas.no/images/stories/exotic/pdf_datasheet/f8-appnote.pdf
It is so engaging I don't need to change it, yet the curiosity remains - could it sound better?
http://www.seas.no/images/stories/exotic/pdf_datasheet/f8-appnote.pdf
It is so engaging I don't need to change it, yet the curiosity remains - could it sound better?