Only for those who insist on modeling a max-flat alignment. The boost at the bottom is unaccounted for room lift. If you design with the room in mind, a BR have give very nice smooth bass with out a hint of boom
Bob
I am sure you are aware that this is derivation of project with OB and open backpack. I am trying to modify that with sealed box and the reason is simple. My living room is not particularly HAF friendly (WAF-HusbandAF). Hence the need for sealed box (the least troublesome for positioning in the room). If you think TL could do that without problems I am not running away from that either...just don't know to calculate this.
My idea was to let that woofer go to 400Hz but on the other forum they started to object (phase shift etc. not familiar with that) and suggested to me 200Hz.
So if this is the concept, what should be the volume of the sealed box?
Or the box with variovent?
Or TL?
What should be the elements for Xover for 400Hz?
My idea was to let that woofer go to 400Hz but on the other forum they started to object (phase shift etc. not familiar with that) and suggested to me 200Hz.
So if this is the concept, what should be the volume of the sealed box?
Or the box with variovent?
Or TL?
What should be the elements for Xover for 400Hz?
Baffle step compensation is possible with a shelf filter, I do use a coil with a resistor for that, I am now busy to make two closed boxes with variovents to look of this do work fine, it has to go to 60 hz, I do use the natural fall off to calculate crossover, (crossover points on fall off point box of baffle).
I do use the AD 8066 phillips old speaker 1972, she sound very well when compensated, I do use the tweeter crossover point on the high fall off of bass speaker (4000 hz in my case), to simplify things and free extra section, 6 dB gets 12 Db when speaker has 6 dB fall of for example whithout fase error (if I right afcourse)...
Hope the aperiodic approach works for you. Please report back with your results.
There are good resources on aperiodic box stuffing, but a brief summery is line the box with acoustic stuffing but leave a clear path between the driver and the vent. The vent is tuned by varying the vent stuffing until you get the sound you want. Blotting paper or even kitchen roll paper makes good vent stuffing material and allows for very precise stuffing.
Shoog
There are good resources on aperiodic box stuffing, but a brief summery is line the box with acoustic stuffing but leave a clear path between the driver and the vent. The vent is tuned by varying the vent stuffing until you get the sound you want. Blotting paper or even kitchen roll paper makes good vent stuffing material and allows for very precise stuffing.
Shoog
Hi,
While this may give an idea ..
My small OB with FE126eN and DT300 Monacor. Tweeter is optional, because Fostex works well without.
Xover is near 190 hz, 12 db, add a BSC and a cap in //
Sub is MLTL Bipole with two 8 pouces (TB Speaker)
I am not comfortable with complex Xover, so I never "cut" bandwidth between 200 to 4000 hz.
I think ears (brain) are more sensitive in this area, with distorsion, of phase particularly.
near field response curve.
Phil.
While this may give an idea ..
My small OB with FE126eN and DT300 Monacor. Tweeter is optional, because Fostex works well without.
Xover is near 190 hz, 12 db, add a BSC and a cap in //
Sub is MLTL Bipole with two 8 pouces (TB Speaker)
I am not comfortable with complex Xover, so I never "cut" bandwidth between 200 to 4000 hz.
I think ears (brain) are more sensitive in this area, with distorsion, of phase particularly.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
near field response curve.
Phil.
I did read the falloff is even 18 dB oct, with a 6 dB oct low pass I get a nice phase coherent system?, when I do let the crossover point do set on the low end where the subwoofer kicks in who is filtered to 60 hz (16Hz 60 Hz), and a high falloff 6dB to tweeter.
Bass speaker will be impedance corrected to smoot out mids.
philFR use the natural falloff in open baffles to the wideband speaker on this point you can high pass to fostex and have extra section for free, (6dB( I do not now if every speaker can be used this way, I have to try myself the sound of it, maybe the woofer gets in fase trouble when not low pass it and use the speaker own 6 dB falloff as a extra filter section, so a 5 dB filter gets 12 dB without the extra fase errors.
regards
Bass speaker will be impedance corrected to smoot out mids.
philFR use the natural falloff in open baffles to the wideband speaker on this point you can high pass to fostex and have extra section for free, (6dB( I do not now if every speaker can be used this way, I have to try myself the sound of it, maybe the woofer gets in fase trouble when not low pass it and use the speaker own 6 dB falloff as a extra filter section, so a 5 dB filter gets 12 dB without the extra fase errors.
regards
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This is my open baffle measurement I use open baffle with subwoofer T_TQWT isobaric wsp26 s visaton woofers (xmax 22 mm).
I do remove the two baffles and make two 18 liter Aperiodic ones who has 60 hz highpass filter (6dB) as test.
But I want in future make horns, a tapped horn with two little horns who go to 60 a 80 hz, best for sub is 50 a 60 Hz bt this is offtopic now.
I do remove the two baffles and make two 18 liter Aperiodic ones who has 60 hz highpass filter (6dB) as test.
But I want in future make horns, a tapped horn with two little horns who go to 60 a 80 hz, best for sub is 50 a 60 Hz bt this is offtopic now.
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this is not meant for me i presume.
I go make sawdust and make a variovent let you all now how that 1972 phillips woofer do, nice a speaker of sustainable quality and still working fine, all producs has to be this way good for nature and sources, bad for people who want to get rich fast...
Last time I auditioned my vintage German field coil speakers from the 1940's with their Goodman 10" woofers from the 70's - the audience simply couldn't believe that vintage drivers could deliver such a fantastically alive and natural sound.
Shoog
A spiral sealed TL has same freq response as OB
If you are looking for clean dynamics and flat freq response of an OB but don't care for the back wave ambience or how it causes bass to fall off at -12dB then the spiral sealed TL is a good alternative. In the Nautaloss Ref Speaker thread I demonstrated that it works for both the full range (200 Hz to 20kHz) and the bass (50 Hz and up to XO point - as high as you want up to 3kHz). The idea is that a tapering TL that is sealed and stuffed acts as an acoustic black hole to absorb the back wave without any reflections. http://www.diyaudio.com/forums/full-range/247598-nautaloss-ref-monitor.html
Here is comparison of Nautaloss and OB for the full range. The sharp drop at 300 Hz is a room effect - removed later with room treatment and placement.
If you are looking for clean dynamics and flat freq response of an OB but don't care for the back wave ambience or how it causes bass to fall off at -12dB then the spiral sealed TL is a good alternative. In the Nautaloss Ref Speaker thread I demonstrated that it works for both the full range (200 Hz to 20kHz) and the bass (50 Hz and up to XO point - as high as you want up to 3kHz). The idea is that a tapering TL that is sealed and stuffed acts as an acoustic black hole to absorb the back wave without any reflections. http://www.diyaudio.com/forums/full-range/247598-nautaloss-ref-monitor.html
Here is comparison of Nautaloss and OB for the full range. The sharp drop at 300 Hz is a room effect - removed later with room treatment and placement.
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Last time I auditioned my vintage German field coil speakers from the 1940's with their Goodman 10" woofers from the 70's - the audience simply couldn't believe that vintage drivers could deliver such a fantastically alive and natural sound.
Recently I bought vintage pair of 3way speakers made in Yugoslavia by 'Iskra' from Kranj, present Slovenia. Model GK 40 from 1979 I believe. Two identical drivers side by side and below is 8incher midwoofer. Paper membranes of course. 'As is' they play almost great. With some tweakin' (remove back wall of the box, plug midwoofer directly to speakers contacts and add conds on tweeter (from 1.5 to 3.0 uF) and they do sing.
But not all vintage drivers sing good. Friends of mine tested that so called midwoofer which is really broadbend, against 'GREENs' and it beated them. Or we had extra good ISKRA driver and ruinned SABA?
Recently I bought vintage pair of 3way speakers made in Yugoslavia by 'Iskra' from Kranj, present Slovenia. Model GK 40 from 1979 I believe. Two identical drivers side by side and below is 8incher midwoofer. Paper membranes of course. 'As is' they play almost great. With some tweakin' (remove back wall of the box, plug midwoofer directly to speakers contacts and add conds on tweeter (from 1.5 to 3.0 uF) and they do sing.
But not all vintage drivers sing good. Friends of mine tested that so called midwoofer which is really broadbend, against 'GREENs' and it beated them. Or we had extra good ISKRA driver and ruinned SABA?
SABA's are reputed to be bright and ragged due to air been trapped behind the dusty cap which behaves in an uncontrolled vway and causes a midrange peak. The solution is to remove the dustcap. I have removed the dustcaps from all my speakers and added simple phase plugs and this significantly cleans up the top end.
My current Graetz Field coil drivers have bicones (an annular ring mid way up the cone designed to allow the middle to move more freely than the outer) and these have a significant upper midrange peak as a consequence. I had to treat them with rubber solution on the annular ring to calm this down. They are still not as refined as my Isophon's, which use a curved cone profile to achieve the same result.
it is rare that these vintage drivers don't benefit from a bit of judicious cone treatment.
Shoog
But there is something else better in these vintage speakers, and even more in their enclosures.
I think we all more or less forget to listen the music and we all search for something that we perhaps arteficialy created all these years. These old ISKRAs ('Sparkles') were really discovery for me after all these years. They play almost everything...C string on the cello goes really low and it is there. Just not that intensity we are looking today.
Dunno why I am so sentimental...just thoughts...but it can't hurt?
Cheers
branko
I think we all more or less forget to listen the music and we all search for something that we perhaps arteficialy created all these years. These old ISKRAs ('Sparkles') were really discovery for me after all these years. They play almost everything...C string on the cello goes really low and it is there. Just not that intensity we are looking today.
Dunno why I am so sentimental...just thoughts...but it can't hurt?
Cheers
branko
Last time I auditioned my vintage German field coil speakers from the 1940's with their Goodman 10" woofers from the 70's - the audience simply couldn't believe that vintage drivers could deliver such a fantastically alive and natural sound.
Shoog
Maybe because in these days there more natural sources for the speaker parts.
And afcourse everything that get old, get also the history of live it lived, like houses, I like old houses like castels of middle ages for example, it has such beautifull energy I can feel, same with speakers, a voice coil of paper is such natural part who give such nice sound..
regards
short offtopic but do know someone or this speaker is available in europe?
MCM Audio Select 8'' High Excursion Woofer - 120W RMS 4ohm | 55-2421 (552421) | MCM Audio Select
fantastic candidate for tapped horn when I get there some day.
unkwown speaker.
MCM Audio Select 8'' High Excursion Woofer - 120W RMS 4ohm | 55-2421 (552421) | MCM Audio Select
fantastic candidate for tapped horn when I get there some day.
unkwown speaker.
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