I'm planning to make some loudspeakers for my GF,
at first I was thinking needles, but right now I've ordered a pair of W4-1320,
I haven't seen much TL projects for it except for TABAQ.
back loaded horn enclosure appears to be very large (or I'm using HornResp incorrectly)
Right now I'm constraining on geometrical dimensions, lets say max 15x15x140cm and planning to hit atleast 65Hz (55 ?), most likely speakers will be against a wall.
I have a few questions regarding this endeavor:
1) Can 65-55-45Hz produced with a reasonable listening levels ?
2) Can I simulate TL's with HornResp or I'm better with dedicated spreadsheet for them ?
3) I'm getting ripples in my Hornresp response, what can I do about them, can they be damped - lining the horn with absorbent material? More to that - why are they present in the first place, increasing horn size reduces ripples though.
4) Back loaded horn is effectively a comb filter, how do you reduce this effect ?
5) Is my dimension constrain unreasonable ?
6) I can machine my enclosures on CNC, what neat tricks I can use in my case (smooth contours and bends are included), like things to reduce internal reflections and whatnot ?
7) Placing horn's mouth near the floor effectively enlarges the mouth, by how much, can any mouth contouring improve this ?
at first I was thinking needles, but right now I've ordered a pair of W4-1320,
I haven't seen much TL projects for it except for TABAQ.
back loaded horn enclosure appears to be very large (or I'm using HornResp incorrectly)
Right now I'm constraining on geometrical dimensions, lets say max 15x15x140cm and planning to hit atleast 65Hz (55 ?), most likely speakers will be against a wall.
I have a few questions regarding this endeavor:
1) Can 65-55-45Hz produced with a reasonable listening levels ?
2) Can I simulate TL's with HornResp or I'm better with dedicated spreadsheet for them ?
3) I'm getting ripples in my Hornresp response, what can I do about them, can they be damped - lining the horn with absorbent material? More to that - why are they present in the first place, increasing horn size reduces ripples though.
4) Back loaded horn is effectively a comb filter, how do you reduce this effect ?
5) Is my dimension constrain unreasonable ?
6) I can machine my enclosures on CNC, what neat tricks I can use in my case (smooth contours and bends are included), like things to reduce internal reflections and whatnot ?
7) Placing horn's mouth near the floor effectively enlarges the mouth, by how much, can any mouth contouring improve this ?
1/ Depends what you call 'reasonable.'
2/ No (unless David has added a damping facility), but you can simulate an undamped QW pipe. For TLs, you're better off with Martin King's MathCAD worksheets.
3/ Yes, you can attenuate them to a greater or lesser extent by strategic damping. If a horn is undersized for the nominal tuning frequency you have an acoustic impedance mismatch at the terminus, and a standing wave reflected back along the horn.
4/ See above.
5/ Dpends on how stringent your (or rather your GF's) performance criteria are for the speakers.
6/ Depends on the box. I generally avoid smooth internal contours for back-horns, since they promote greater efficiency at the top of the cabinet BW, while having relatively little effect lower down. Decent external roundovers rarely go amiss though.
7/ Depends on what other reflection boundaries are nearby. Assuming 1/2 radiation space, i.e. a floor & no other boundaries, it's doubled the size of the terminus.
2/ No (unless David has added a damping facility), but you can simulate an undamped QW pipe. For TLs, you're better off with Martin King's MathCAD worksheets.
3/ Yes, you can attenuate them to a greater or lesser extent by strategic damping. If a horn is undersized for the nominal tuning frequency you have an acoustic impedance mismatch at the terminus, and a standing wave reflected back along the horn.
4/ See above.
5/ Dpends on how stringent your (or rather your GF's) performance criteria are for the speakers.
6/ Depends on the box. I generally avoid smooth internal contours for back-horns, since they promote greater efficiency at the top of the cabinet BW, while having relatively little effect lower down. Decent external roundovers rarely go amiss though.
7/ Depends on what other reflection boundaries are nearby. Assuming 1/2 radiation space, i.e. a floor & no other boundaries, it's doubled the size of the terminus.
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I had a pair of them in a MLTL that I was using for a 2.1 system for my TV, they sounded fine, went down to ~ 60 Hz. Eventually I put them in much smalled sealed boxes crossed to the sub because of size constraints and thought they sounded better sealed when relieved of the bottom octave. Better mids and highs. Still using them for my TV, sound way better than they should for the cost.
PJN
PJN
Thanks Scottmoose, this is what I was hoping to hear.
1) Reasonable as in loud enough for some relaxed listening.
2) Thought so.
3) In other words it isn't woth it, you can't urge (trade sensitivity for extension) an undesized horn to play correctly. Oh and if I do want to damp it, how should it be done ? For example some zig-zagging on the surface or some solid absorbent material ?
4) Check.
5) Hehe, just trying to sqeeze the best performance and learning what else is out there.
6) That makes sense.
7) I guess it all has to do with acoustic impedance again.
The only issue I see with TABAQ - if I build them taller - that means raising the port from the floor and loosing some extension, perhaps moving the port to the back and placing them near the wall will help ?
1) Reasonable as in loud enough for some relaxed listening.
2) Thought so.
3) In other words it isn't woth it, you can't urge (trade sensitivity for extension) an undesized horn to play correctly. Oh and if I do want to damp it, how should it be done ? For example some zig-zagging on the surface or some solid absorbent material ?
4) Check.
5) Hehe, just trying to sqeeze the best performance and learning what else is out there.
6) That makes sense.
7) I guess it all has to do with acoustic impedance again.
The only issue I see with TABAQ - if I build them taller - that means raising the port from the floor and loosing some extension, perhaps moving the port to the back and placing them near the wall will help ?
Not a problem.
Still doesn't really mean much as everyone has different definitions of relaxed listening (some find Metallica's live S&M album relaxing), & the space comes into play. Winging it to assume you mean relatively undemanding material without large LF dynamic swings & the room isn't a barn, probably.
I didn't say that. Most back-horns are compromised & rely on QW action to prop up the LF below the point at which they are impedance matched. Done carefully, many people are happy with the results, especially if they are designed to use the room's reflection boundary conditions (1/8 space & 1/4 space loading). They just aren't impedance matched down to Fo, & therefore you need to pay attention to damping them, or reducing these effects in other ways. How you would damp it, as you would expect, depends on the specific design, so there is no one-size-fits-all answer to that I'm afraid. Would that there were. Usually I would suggest avoiding overly rigid materials since their absorbant properties are insufficient. I'm not too keen on foam either. Acoustic fiberglass, dacron, thick carpet underlay, ultratouch etc. are all effective when used sensibly.
Re the TABAQ, I presume you mean add a cavity under it to lift them up, right? Shouldn't be too much of an issue. I doubt you'd loose much in the way of LF gain per se, but the details of the response will alter somewhat. Exact cabinet location is usually a matter of experimentation, since the room dominates below ~300Hz (give or take).
Still doesn't really mean much as everyone has different definitions of relaxed listening (some find Metallica's live S&M album relaxing), & the space comes into play. Winging it to assume you mean relatively undemanding material without large LF dynamic swings & the room isn't a barn, probably.
I didn't say that. Most back-horns are compromised & rely on QW action to prop up the LF below the point at which they are impedance matched. Done carefully, many people are happy with the results, especially if they are designed to use the room's reflection boundary conditions (1/8 space & 1/4 space loading). They just aren't impedance matched down to Fo, & therefore you need to pay attention to damping them, or reducing these effects in other ways. How you would damp it, as you would expect, depends on the specific design, so there is no one-size-fits-all answer to that I'm afraid. Would that there were. Usually I would suggest avoiding overly rigid materials since their absorbant properties are insufficient. I'm not too keen on foam either. Acoustic fiberglass, dacron, thick carpet underlay, ultratouch etc. are all effective when used sensibly.
Re the TABAQ, I presume you mean add a cavity under it to lift them up, right? Shouldn't be too much of an issue. I doubt you'd loose much in the way of LF gain per se, but the details of the response will alter somewhat. Exact cabinet location is usually a matter of experimentation, since the room dominates below ~300Hz (give or take).
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By relaxed listening I mean some bossa-nova, lounge and what not, room is roughly 5 by 6m.
For now my interest in horns had subsided, its a bit too broad topic, I just don't have the time to invest in it right now.
As for TABAQ - yes I'm planning on making them a bit taller.
My W4-1320 have arrived yesterday so its time to burn them in a bit.
For now my interest in horns had subsided, its a bit too broad topic, I just don't have the time to invest in it right now.
As for TABAQ - yes I'm planning on making them a bit taller.
My W4-1320 have arrived yesterday so its time to burn them in a bit.
It does with TABAQ, long time since a messured it but look at post #30 here.
http://www.diyaudio.com/forums/full-range/88787-tabaq-tl-tang-band-3.html
If you look at the red line, its messured from the port and if i understand the
discussion after my messurements you should lower that -7,35DB to get it right.It sounds pretty low for me.
Solve
http://www.diyaudio.com/forums/full-range/88787-tabaq-tl-tang-band-3.html
If you look at the red line, its messured from the port and if i understand the
discussion after my messurements you should lower that -7,35DB to get it right.It sounds pretty low for me.
Solve
Do you have any idea what is the low end extension (-3db) of TABAQ with w4 1320?
Do they do synthetic bass kicks (wall trembling sound = about 55hz)?
I am skeptical because the original TABAQ started to rolloff at 53 in simulation but that was for a driver with a much lower Vas then the w4 1320.
The real question is how low will the w4 1320 go without the help of a horn. A 10 liter TABAQ sounds to me like a very strict diet for this driver... the BIB is 34.5 liters... somewhere in between there is a down to earth TL that should work as low as who knows ... I suspect not lower than 45hz. Somebody who worked with the driver might know more about the low end extension.
Do they do synthetic bass kicks (wall trembling sound = about 55hz)?
I am skeptical because the original TABAQ started to rolloff at 53 in simulation but that was for a driver with a much lower Vas then the w4 1320.
The real question is how low will the w4 1320 go without the help of a horn. A 10 liter TABAQ sounds to me like a very strict diet for this driver... the BIB is 34.5 liters... somewhere in between there is a down to earth TL that should work as low as who knows ... I suspect not lower than 45hz. Somebody who worked with the driver might know more about the low end extension.
lol, wasn't there a message somewhere about a guy who said the sheetrock in his house started to seperate from the joints with speakers that go down to (can't remember exactly) either 16hz or 14hz?
Weird thing I noticed on the apple website: they stated the range for the Creative T12 as being 20-20,000hz. The ones I bought I think go down to 45hz. So I don't know if that was a typo. I still don't understand the bassflex technology. It looks a little like a passive radiator?
Weird thing I noticed on the apple website: they stated the range for the Creative T12 as being 20-20,000hz. The ones I bought I think go down to 45hz. So I don't know if that was a typo. I still don't understand the bassflex technology. It looks a little like a passive radiator?
Hi
My original TABAQ har been updated with W4-1320SA. Same cabintet, same BSC - no changes. The sound is very clean - just like it should be. You could, however, reduce the damping with a third. This gives a more lively bass, but it is not neutral any more. I use the 100g damping as the original TABAQ.
I do not have advanced measuring tools, but TABAQ with this 4" driver has useful output down to 35 - 40 Hz when placed against the wall.
The driver would probably do better in a cabinet with more volum, but that is not the intention of TABAQ.
Regards
Bjorn Johannesen
My original TABAQ har been updated with W4-1320SA. Same cabintet, same BSC - no changes. The sound is very clean - just like it should be. You could, however, reduce the damping with a third. This gives a more lively bass, but it is not neutral any more. I use the 100g damping as the original TABAQ.
I do not have advanced measuring tools, but TABAQ with this 4" driver has useful output down to 35 - 40 Hz when placed against the wall.
The driver would probably do better in a cabinet with more volum, but that is not the intention of TABAQ.
Regards
Bjorn Johannesen
.
Thank you for your answers, and for designing the TABAQ in the first place. You have answered my question and probably the one for VEC7OR. 35-40 Hz is a surprise for me, I didn't expect it to go that low, this is probably due to Xmax; the driver looks bass thin in hornresp below Fs, probably due to low Qts. Did you design the TABAQ with a gradual rolloff to get good extension bellow 55hz?
One more thing for the record: if GM is generous enough to shine the light on this one - what would be the optimum volume for an enclosure tuned to 0.707Fs (=53hz) for the w4 1320? ... the down to earth TL I was talking about earlier. I think it's going to be above 20 liters (compared with only 10 of the TABAQ).
Thank you for your answers, and for designing the TABAQ in the first place. You have answered my question and probably the one for VEC7OR. 35-40 Hz is a surprise for me, I didn't expect it to go that low, this is probably due to Xmax; the driver looks bass thin in hornresp below Fs, probably due to low Qts. Did you design the TABAQ with a gradual rolloff to get good extension bellow 55hz?
One more thing for the record: if GM is generous enough to shine the light on this one - what would be the optimum volume for an enclosure tuned to 0.707Fs (=53hz) for the w4 1320? ... the down to earth TL I was talking about earlier. I think it's going to be above 20 liters (compared with only 10 of the TABAQ).
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