One question about the TBs
Timn8ter and others,
One question which bothers me about the TB drivers is their low rated power output. Do you get adequate SPL levels for using them as your main stereo speakers with just one driver per channel? Their sensitivity is middle of the road, and their power rating (e.g. for the 871) is just 15W.
Does this mean that anyone planning to build their main stereo speakers (as against surrounds and the like) using these drivers will have to commit to something like a line array? Is a single driver used as a wide-range midrange per channel an option at all? I don't mind adding a tweeter and a large woofer to strengthen the extremities, but will a single TB871 used as wide-range midrange deliver enough SPL for "normal" loud listening? (I guess we're talking of transient peaks of 110dB?)
I have a pair of JX92S which I'm very impressed with. I've been really tempted to buy a pair of the TB 871 for my next pair because of their prices and reported very nice sound. But this is the only thing that holds me back. Any comments from the experienced ones here will be greatly useful.
regards,
Tarun
Timn8ter and others,
One question which bothers me about the TB drivers is their low rated power output. Do you get adequate SPL levels for using them as your main stereo speakers with just one driver per channel? Their sensitivity is middle of the road, and their power rating (e.g. for the 871) is just 15W.
Does this mean that anyone planning to build their main stereo speakers (as against surrounds and the like) using these drivers will have to commit to something like a line array? Is a single driver used as a wide-range midrange per channel an option at all? I don't mind adding a tweeter and a large woofer to strengthen the extremities, but will a single TB871 used as wide-range midrange deliver enough SPL for "normal" loud listening? (I guess we're talking of transient peaks of 110dB?)
I have a pair of JX92S which I'm very impressed with. I've been really tempted to buy a pair of the TB 871 for my next pair because of their prices and reported very nice sound. But this is the only thing that holds me back. Any comments from the experienced ones here will be greatly useful.
regards,
Tarun
Re: Re: Re: Do I let the Jordan go down full-depth?
I run the Nonsuch 4s full-range, without any filtering. I prefer this. I've tried active high-pass filters at low frequencies but the main audible difference is a loss of clarity. Better to drive them 'neat' (this may not be true for Tangband drivers, I don't know).
The bass enclosures are driven via a 24dB per octave valve low-pass filter - it was designed for Seventh Veil by Chris Found of CF Media and sounds beautiful.
In truth I don't think of the Little Awesomes as subwoofers, more as bass enclosures. The system was designed as a 2 way (1 1/2 way really as the full-rangers are unfiltered). However, achieving a low enough crossover frequency gives the freedom to separate the bass from the rest. This gives benefits in room set-up and aesthetics.
tcpip said:
I run the Nonsuch 4s full-range, without any filtering. I prefer this. I've tried active high-pass filters at low frequencies but the main audible difference is a loss of clarity. Better to drive them 'neat' (this may not be true for Tangband drivers, I don't know).
The bass enclosures are driven via a 24dB per octave valve low-pass filter - it was designed for Seventh Veil by Chris Found of CF Media and sounds beautiful.
In truth I don't think of the Little Awesomes as subwoofers, more as bass enclosures. The system was designed as a 2 way (1 1/2 way really as the full-rangers are unfiltered). However, achieving a low enough crossover frequency gives the freedom to separate the bass from the rest. This gives benefits in room set-up and aesthetics.
How loud do you need it?
Admittedly I have a tiny audio room so the TB 871 is fine. They do not handle LOUD very well and probably would not fill a large room. They are best for acoustic music and I do not think they are that good at rock music. But I am getting annoyed by most anything but late '50s jazz and barouque (French esp.) these days so they are perfect.
Admittedly I have a tiny audio room so the TB 871 is fine. They do not handle LOUD very well and probably would not fill a large room. They are best for acoustic music and I do not think they are that good at rock music. But I am getting annoyed by most anything but late '50s jazz and barouque (French esp.) these days so they are perfect.
Re: What about the Jordan JX92S?
Nope, it's not true at all. Quite the opposite is true. I've got a tline that doesn't go super deep, but it has truly remarkable good and tight bass - a Lynn Olson "Ariel." http://www.aloha-audio.com/Arieltxt1.html Perhaps your friend heard a TL system that used bad bass drivers or something.
If you don't use enough stuffing, there will be a boom at 3X the tuned frequency. In that case, I wouldn't say it sounds slow -- just wrong. If you use too much stuffing, bass will suffer, but it will sound too tight, not slow.
The drawbacks to t-lines are 1) large size and 2) relatively difficult to build. Also, until recently there was no good theory to guide in the design.
tcpip said:
Nope, it's not true at all. Quite the opposite is true. I've got a tline that doesn't go super deep, but it has truly remarkable good and tight bass - a Lynn Olson "Ariel." http://www.aloha-audio.com/Arieltxt1.html Perhaps your friend heard a TL system that used bad bass drivers or something.
If you don't use enough stuffing, there will be a boom at 3X the tuned frequency. In that case, I wouldn't say it sounds slow -- just wrong. If you use too much stuffing, bass will suffer, but it will sound too tight, not slow.
The drawbacks to t-lines are 1) large size and 2) relatively difficult to build. Also, until recently there was no good theory to guide in the design.
>I thought that the zig-zagging of the frequency response towards the top end was more a result of distortion and cone breakup and resonances and the like. I don't know enough to know whether I was right...
====
I said audible...... It does get nasty when pushed though.
====
>YES!!!! This has been my theory too, ever since I read Lynn Olson's Ariel pages where he said that only valve amps seem to sound good with the Ariel. Basically, I suspect he's designed his crossover completely taking for granted that the source impedance (i.e. the amp's output impedance) is of the kind that valve amps give you. That must be throwing the crossover off balance when faced with a very-low-Z SS amp. Does this make sense?
====
Only in that he 'voiced' them with tubes, so either some series resistance or an impedance matching transformer would be required if SS driven.
====
> Does this mean that most speakers with passive XOs are either going to give off their best with SS or valve but not both?
====
For a given XO design, it's true for all speakers AFAIK. Frankly, since most of the time an SS amp is just idling along down where its non-linear, I believe all except the most inefficient systems using SS amps should have enough series resistance added to keep it in its linear power BW.
====
>I was thinking of putting a stiffer vibration-absorbing sheet or pad on the inner rear wall, directly behind the driver, to absorb as much as possible of the rear wave. Something like a homegrown composite-sandwich version of a Deflex pad (I can't buy those in India). Do you think something like that would help?
====
From a strictly technical POV, I think it's a waste of time/materials with this particular design, but not having tried it I can't say for sure, so if you try it let us know if you think it's worth doing.
====
>Tell me, where do you think I should place the tweeter? Above the box on a small open baffle, or inside the box as close to the JX92S as possible, as conventional theory dictates? Any suggestions?
====
Frankly, I don't know why you would want a tweeter as it sounds fine if listened to slightly off axis, but it depends on the XO order as to the best placement.
GM
====
I said audible......
It does get nasty when pushed though.====
>YES!!!! This has been my theory too, ever since I read Lynn Olson's Ariel pages where he said that only valve amps seem to sound good with the Ariel. Basically, I suspect he's designed his crossover completely taking for granted that the source impedance (i.e. the amp's output impedance) is of the kind that valve amps give you. That must be throwing the crossover off balance when faced with a very-low-Z SS amp. Does this make sense?
====
Only in that he 'voiced' them with tubes, so either some series resistance or an impedance matching transformer would be required if SS driven.
====
> Does this mean that most speakers with passive XOs are either going to give off their best with SS or valve but not both?
====
For a given XO design, it's true for all speakers AFAIK. Frankly, since most of the time an SS amp is just idling along down where its non-linear, I believe all except the most inefficient systems using SS amps should have enough series resistance added to keep it in its linear power BW.
====
>I was thinking of putting a stiffer vibration-absorbing sheet or pad on the inner rear wall, directly behind the driver, to absorb as much as possible of the rear wave. Something like a homegrown composite-sandwich version of a Deflex pad (I can't buy those in India). Do you think something like that would help?
====
From a strictly technical POV, I think it's a waste of time/materials with this particular design, but not having tried it I can't say for sure, so if you try it let us know if you think it's worth doing.
====
>Tell me, where do you think I should place the tweeter? Above the box on a small open baffle, or inside the box as close to the JX92S as possible, as conventional theory dictates? Any suggestions?
====
Frankly, I don't know why you would want a tweeter as it sounds fine if listened to slightly off axis, but it depends on the XO order as to the best placement.
GM
Re: ML TL idea...
I first tried driving my Ariels with a solid state Hardon Karmon home theater amp, and they sounded good, but I suspected they could do better. I also tried a Dynakit 70 amp. Simply pitiful. (That amp might have need new tubes or something.) Then I tried a Rotel RA-02, a 40 watt solid state unit. BINGO!! Ooo. My ears threw a party for my brain. If you see Mr. Olson, you might let him know.
tcpip said:
I first tried driving my Ariels with a solid state Hardon Karmon home theater amp, and they sounded good, but I suspected they could do better. I also tried a Dynakit 70 amp. Simply pitiful. (That amp might have need new tubes or something.) Then I tried a Rotel RA-02, a 40 watt solid state unit. BINGO!! Ooo. My ears threw a party for my brain. If you see Mr. Olson, you might let him know.
GM said:>I thought that the zig-zagging of the frequency response towards the top end was more a result of distortion and cone breakup and resonances and the like. I don't know enough to know whether I was right...
====
I said audible......
====
>YES!!!! This has been my theory too, ever since I read Lynn Olson's Ariel pages where he said that only valve amps seem to sound good with the Ariel. Basically, I suspect he's designed his crossover completely taking for granted that the source impedance (i.e. the amp's output impedance) is of the kind that valve amps give you. That must be throwing the crossover off balance when faced with a very-low-Z SS amp. Does this make sense?
====
Only in that he 'voiced' them with tubes, so either some series resistance or an impedance matching transformer would be required if SS driven.GM
This is probably a naive question, but how would one add series resistance? Where would you put the resistors and how would you choose the values?
[Added a bit later...] Google is a wonder! Look what I found: http://www.trueaudio.com/post_013.htm
Real Bass from TB W3871-S
GringoAudio,
just to go back to your poston 10/17: yes i get real bass. could i ask a suppose type question?
suppose the purpose was home theater (and in this suppose, the home theater doesn't need to get too loud - i can't put that in spl terms, since i guess this is a matter of taste). and suppose the room was set up as follows:
about 15ft wide by 22ft long.
the front, side and rear pairs of speakers are in the ceiling.
there is a center channel, and it sits on top of a 36"tv.
there is a pair of sunfire subs with the crossover set at 120hz.
i use a lexicon dc-1 where the front/side/rear ceiling speakers are modeled as 'small', so they don't get a full bass feed.
the current setup uses a basic 6" ceiling speaker with a concentric 1/2" dome tweeter. since all speakers are the same, the sound is actually quite good. (an engineer from lexicon suggested that just to get started, with a tight 'budget', keep all the speakers the same and you will get good results -- and he was right).
given you had a box volume of 360cu in, i could fit a w3871-s in the ceiling cutouts and have room for a port behind the fascia grille.
think this would work? you did your design with a 300hz low pass, that's a bit more than an octave higher than the 120hz. did you pick it because of clipping experiences? or because you had a good clean subwoofer that could go to 300hz. what was the slope (6 or 12 db/octave)? think i could get away with 120hz and a 24db/octave slope?
the amps will be the mini-aleph designs from the pass forum, probably built for 10watts and no more. so i don't think i can damage the tangband units -- but i might be able to bottom them out.
anyone else tried this type of setup? is it unreasonable to think that you coud fill a room with 6 of these drivers and a center channel? perhaps the way to go is keep them at 120hz/24db per octave, and let the subwoofers roll over at no more than 12db/octave? or perhaps change the crossover point to 150 or 180hz? i think if it goes much higher, then the subwoofers can be 'found' and that's not a good thing.
anyway, nice work you did. thought i'd ask if this has been tried.
thanks, ron
GringoAudio,
just to go back to your poston 10/17: yes i get real bass. could i ask a suppose type question?
suppose the purpose was home theater (and in this suppose, the home theater doesn't need to get too loud - i can't put that in spl terms, since i guess this is a matter of taste). and suppose the room was set up as follows:
about 15ft wide by 22ft long.
the front, side and rear pairs of speakers are in the ceiling.
there is a center channel, and it sits on top of a 36"tv.
there is a pair of sunfire subs with the crossover set at 120hz.
i use a lexicon dc-1 where the front/side/rear ceiling speakers are modeled as 'small', so they don't get a full bass feed.
the current setup uses a basic 6" ceiling speaker with a concentric 1/2" dome tweeter. since all speakers are the same, the sound is actually quite good. (an engineer from lexicon suggested that just to get started, with a tight 'budget', keep all the speakers the same and you will get good results -- and he was right).
given you had a box volume of 360cu in, i could fit a w3871-s in the ceiling cutouts and have room for a port behind the fascia grille.
think this would work? you did your design with a 300hz low pass, that's a bit more than an octave higher than the 120hz. did you pick it because of clipping experiences? or because you had a good clean subwoofer that could go to 300hz. what was the slope (6 or 12 db/octave)? think i could get away with 120hz and a 24db/octave slope?
the amps will be the mini-aleph designs from the pass forum, probably built for 10watts and no more. so i don't think i can damage the tangband units -- but i might be able to bottom them out.
anyone else tried this type of setup? is it unreasonable to think that you coud fill a room with 6 of these drivers and a center channel? perhaps the way to go is keep them at 120hz/24db per octave, and let the subwoofers roll over at no more than 12db/octave? or perhaps change the crossover point to 150 or 180hz? i think if it goes much higher, then the subwoofers can be 'found' and that's not a good thing.
anyway, nice work you did. thought i'd ask if this has been tried.
thanks, ron
No sorry......
I used the 3" TB 871 Full range and used 4" TB drivers to augment the bass. THESE 4" units (TB654 I believe from Parts Express) were crossed over at 300 HZ. These 4" boxes have an F# point of 55HZ (I think.. can't remember exactly) so I definitely have better bass now. Although I must admit it was just fine for classical music without the 4" units. I cannot tell you if these units would fill your space but I tend to think they would. I would protect them from the big unmusical excursions Home Theatre appllications create with Hi Pass filter caps. I have yet to get another amp to drive my Mission Isobaric subwoofer($50 Cdn at a pawnshop) but i look forward to even lower bass then for the Theatre soundtracks!!
871 T/S specs. from Creative Sound
http://www.creativesound.ca/details.php?model=W3871S
871 specs from TB through Nuera (this speaker is and exclusive design by and for Nuera who distributes to Creative Sound only so these are he only two sources anywhere)
http://www.nuera-acoustic.ca/products/datasheets/w3-871s.jpg
I used the 3" TB 871 Full range and used 4" TB drivers to augment the bass. THESE 4" units (TB654 I believe from Parts Express) were crossed over at 300 HZ. These 4" boxes have an F# point of 55HZ (I think.. can't remember exactly) so I definitely have better bass now. Although I must admit it was just fine for classical music without the 4" units. I cannot tell you if these units would fill your space but I tend to think they would. I would protect them from the big unmusical excursions Home Theatre appllications create with Hi Pass filter caps. I have yet to get another amp to drive my Mission Isobaric subwoofer($50 Cdn at a pawnshop) but i look forward to even lower bass then for the Theatre soundtracks!!
871 T/S specs. from Creative Sound
http://www.creativesound.ca/details.php?model=W3871S
871 specs from TB through Nuera (this speaker is and exclusive design by and for Nuera who distributes to Creative Sound only so these are he only two sources anywhere)
http://www.nuera-acoustic.ca/products/datasheets/w3-871s.jpg
>ML TL photos I've seen seem to place the vent at the very bottom of the enclosure. Is this the rule to follow?
====
The sim program assumes a big round pipe with a little round pipe sticking out the bottom, so as long as the big pipe is acoustically large WRT its dims it can be any width:depth ratio you want it to be within reason, ditto the vent as long as it's somewhere near/at the bottom. If the driver(s) are used up into the BW where the cab appears acoustically large, then more care should be taken in choosing a width:depth ratio to minimize reflections back through the diaphragm(s).
====
>Anything else I need to keep in mind?
====
Nothing comes to mind beyond what I've already listed.
GM
====
The sim program assumes a big round pipe with a little round pipe sticking out the bottom, so as long as the big pipe is acoustically large WRT its dims it can be any width:depth ratio you want it to be within reason, ditto the vent as long as it's somewhere near/at the bottom. If the driver(s) are used up into the BW where the cab appears acoustically large, then more care should be taken in choosing a width:depth ratio to minimize reflections back through the diaphragm(s).
====
>Anything else I need to keep in mind?
====
Nothing comes to mind beyond what I've already listed.
GM
I did it
i built them as GringoAudio did shown in the beginning of this thread - i�Lm amazed ! don�Lt expect to get ever more for my money. they just smoke my fe103‡” in solo tqwt, filter isn�Lt necessary anyway. soundstage is wide open and away from the speakers. and yes, they do bass ... 
i built them as GringoAudio did shown in the beginning of this thread - i�Lm amazed ! don�Lt expect to get ever more for my money. they just smoke my fe103‡” in solo tqwt, filter isn�Lt necessary anyway. soundstage is wide open and away from the speakers. and yes, they do bass ... Attachments
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