godzilla,
You have to try an open baffle.
The larger the better and offset the driver so no equal distances.
I've wanted to try something on a 4' x 6'.
Driver 18 1/3" from left, 29 2/3" from right, 48" from top.
True 1 : 1.618 ratio.
Using a b20 I'd expect it'll go below to a bit below 200hz.
You may want to cover the front with felt or something because it is a whole lot of reflective surface. Slide it up against the front wall for more bass or make a foam box to enclose the backside of the driver. That way you get the "un boxy sound" without the artificial front wall dipole bounce.
It's hard to then put any midrange driver into a box, and if you did you will wonder if it would have sounded better open baffle. You'll wonder forever.
Qts near 1 ?
yea, open baffle it.
Norman
You have to try an open baffle.
The larger the better and offset the driver so no equal distances.
I've wanted to try something on a 4' x 6'.
Driver 18 1/3" from left, 29 2/3" from right, 48" from top.
True 1 : 1.618 ratio.
Using a b20 I'd expect it'll go below to a bit below 200hz.
You may want to cover the front with felt or something because it is a whole lot of reflective surface. Slide it up against the front wall for more bass or make a foam box to enclose the backside of the driver. That way you get the "un boxy sound" without the artificial front wall dipole bounce.
It's hard to then put any midrange driver into a box, and if you did you will wonder if it would have sounded better open baffle. You'll wonder forever.
Qts near 1 ?
yea, open baffle it.
Norman
There is a guy whose moto is "I write and read English like Tarzan"
I was his teacher! Ok , I ll try in half chang forum again, to find out if ch252 is good candidate for BVR. What I really wanted is OB ch250, but I triggered negative WAF response(J Esmilla Ob project, I tried to bribe her with generous offer to dress baffles in some nice thick felt by her choice, and to kill some bad baffle reflectons, didn t work), somehow that big half chang box didnt look so bad for her. Hay, seems like good tactics, try something really horrendous just to make pass to what yau really want... So its half-succses for me with half-changs
I was his teacher! Ok , I ll try in half chang forum again, to find out if ch252 is good candidate for BVR. What I really wanted is OB ch250, but I triggered negative WAF response(J Esmilla Ob project, I tried to bribe her with generous offer to dress baffles in some nice thick felt by her choice, and to kill some bad baffle reflectons, didn t work), somehow that big half chang box didnt look so bad for her. Hay, seems like good tactics, try something really horrendous just to make pass to what yau really want... So its half-succses for me with half-changs
>>> regularly come into the house dripping with sweat...
I did that for about a month until wifey found out what i was doing... i had secretly joined an Aikido school. She was relieved that's all it was.
The other day i enjoyed EQ'ing my sealed cabinet Pioneer B20/piezo speakers. For a while i began to question how much better other drivers really were. Distortion ruined my fun ultimately. I am wondering now if higher eff drivers like the Eminence 12lta would respond better to EQ with a small amp like the Sonic Impact. I wonder if distortion would rear its ugly head at louder volumes than the B20. Or will i face the same fate? To enjoy EQ i think i need a more powerful amp.
Godzilla
I did that for about a month until wifey found out what i was doing... i had secretly joined an Aikido school. She was relieved that's all it was.
The other day i enjoyed EQ'ing my sealed cabinet Pioneer B20/piezo speakers. For a while i began to question how much better other drivers really were. Distortion ruined my fun ultimately. I am wondering now if higher eff drivers like the Eminence 12lta would respond better to EQ with a small amp like the Sonic Impact. I wonder if distortion would rear its ugly head at louder volumes than the B20. Or will i face the same fate? To enjoy EQ i think i need a more powerful amp.
Godzilla
EQ'd B20
Godzilla,
Unless there is a need for the small size box, why not let a larger, vented box do the bass EQing? For fun I tried the B20 in a 3cf vented box, similar to your own design (used a 3" dia tube vent). For me there was absolutely no need for bass EQing. Response was strong down to about 30Hz, with usable response to the mid 20's. There was still a loudness (excursion) limit, and that might be a bit low for some. I tried them with a number of bass 'challenges' (music and movies) and heard bass I didn't even know was there. They were a lot of fun, but ultimately too limited in spl capability - you hear that kind of bass and you really want to turn it up just a bit more. In a smaller room a person might not need any more than the B20 in a 3 cf vented box and a tweeter (to balance the extended bass).
The Eminence Beta 12LTA will do about the same thing in a box twice the size (about 6cf) and at 7-8db higher efficiency.
Bob
Godzilla,
Unless there is a need for the small size box, why not let a larger, vented box do the bass EQing? For fun I tried the B20 in a 3cf vented box, similar to your own design (used a 3" dia tube vent). For me there was absolutely no need for bass EQing. Response was strong down to about 30Hz, with usable response to the mid 20's. There was still a loudness (excursion) limit, and that might be a bit low for some. I tried them with a number of bass 'challenges' (music and movies) and heard bass I didn't even know was there. They were a lot of fun, but ultimately too limited in spl capability - you hear that kind of bass and you really want to turn it up just a bit more. In a smaller room a person might not need any more than the B20 in a 3 cf vented box and a tweeter (to balance the extended bass).
The Eminence Beta 12LTA will do about the same thing in a box twice the size (about 6cf) and at 7-8db higher efficiency.
Bob
12LTA in 3cf EQ'd
Godzilla,
Using the Eminence in 3cf with EQ is a good idea. The Eminence has nearly the same Xmax as the B20 (3.2 vs 3 mm), but a much larger cone area. Using it in the 3 cf box with EQ would get you a several more db of bass output, along with more overall headroom due to its much higher sensitivity.
An alternative is to use the B20 in the 3cf box. You would only need to EQ the mids and HF, freeing up the power that went into the bass EQ. This might be a useful gain if you are using the SI amp. I wonder if the distortion you heard with the EQ'd B20 was more amplifier or speaker related? If it was mainly the amp, then freeing up that power might get the spls you are looking for with the B20.
What EQ settings did you use with the b20 in the mids and HF?
Bob
Godzilla,
Using the Eminence in 3cf with EQ is a good idea. The Eminence has nearly the same Xmax as the B20 (3.2 vs 3 mm), but a much larger cone area. Using it in the 3 cf box with EQ would get you a several more db of bass output, along with more overall headroom due to its much higher sensitivity.
An alternative is to use the B20 in the 3cf box. You would only need to EQ the mids and HF, freeing up the power that went into the bass EQ. This might be a useful gain if you are using the SI amp. I wonder if the distortion you heard with the EQ'd B20 was more amplifier or speaker related? If it was mainly the amp, then freeing up that power might get the spls you are looking for with the B20.
What EQ settings did you use with the b20 in the mids and HF?
Bob
>>> I wonder if the distortion you heard with the EQ'd B20 was more amplifier or speaker related?
It is amp related. I slid the EQ up at 62hz +8 and it sounded great on jazz. On rock it distorted badly at medium to loud volumes. 1, 2 and 4k were set - 1 or -2. Eight and 16 were +1 so the upper mids were slightly depressed. I could have adjusted the highs with a different capacitor or a twist of the Lpad. But the bass boost produced a very nice bounce to the sound! I know what solid state sounds like and always preferred tubes (my main rig is tube) and i like the sound of the sonic impact digital amp but am wondering now if the sound of cheap solid state plus a 31 band graphic EQ can sound good too? I worry things will dry out.
I like the idea of an EQ'd Beta 12lta and also like the idea of a simple large ported box for the B20 with slight EQ for the mids. I don't know to build another speaker using the 12lta or keeping my B20s (in smaller 1.3 cubic foot boxes) and buying some cheap SS and an EQ. Fun troubles to ponder certainly. Things could be much worse.
Anyone have any thoughts comparing the B20 to the 12lta? My sites are on those drivers right now for purchase this coming holiday season. Especially since i see the Fostex 207e is up to $90!
>>>> Using the Eminence in 3cf with EQ is a good idea. The Eminence has nearly the same Xmax as the B20 (3.2 vs 3 mm), but a much larger cone area. Using it in the 3 cf box with EQ would get you a several more db of bass output, along with more overall headroom due to its much higher sensitivity.
Thanks for the input Bob! I am thinking of a poor man's Klipsch Heresy or sorts using the 12lta with an inexpensive compression tweeter.
It is amp related. I slid the EQ up at 62hz +8 and it sounded great on jazz. On rock it distorted badly at medium to loud volumes. 1, 2 and 4k were set - 1 or -2. Eight and 16 were +1 so the upper mids were slightly depressed. I could have adjusted the highs with a different capacitor or a twist of the Lpad. But the bass boost produced a very nice bounce to the sound! I know what solid state sounds like and always preferred tubes (my main rig is tube) and i like the sound of the sonic impact digital amp but am wondering now if the sound of cheap solid state plus a 31 band graphic EQ can sound good too? I worry things will dry out.
I like the idea of an EQ'd Beta 12lta and also like the idea of a simple large ported box for the B20 with slight EQ for the mids. I don't know to build another speaker using the 12lta or keeping my B20s (in smaller 1.3 cubic foot boxes) and buying some cheap SS and an EQ. Fun troubles to ponder certainly. Things could be much worse.
Anyone have any thoughts comparing the B20 to the 12lta? My sites are on those drivers right now for purchase this coming holiday season. Especially since i see the Fostex 207e is up to $90!
>>>> Using the Eminence in 3cf with EQ is a good idea. The Eminence has nearly the same Xmax as the B20 (3.2 vs 3 mm), but a much larger cone area. Using it in the 3 cf box with EQ would get you a several more db of bass output, along with more overall headroom due to its much higher sensitivity.
Thanks for the input Bob! I am thinking of a poor man's Klipsch Heresy or sorts using the 12lta with an inexpensive compression tweeter.
I've not heard the 12lta............................
but I remember someone comparing it to the 8" pioneer b20 "cut from the same cloth" very similar sound.
"Eminence made probably at least a dozend versions of the 12" Dual Cone since the 1980's and many before. I used to use earlier versions in Floor Wedge monitors, where they did fine when combined with a tweeter."
"12LT already shows nearly +6db boost to start with and a very ragged frequency response. "
"dunno -- Eminence 12LTA sounds "cleaner" in vocal region than some 8" - but I usually have some sort of box/pipe which is adding coloration reflections back to cone and out vent."
Maybe you should do the afterburner design, seems many like it.
"The Beta 12LTA can make a very, very good midrange on OB."
"and keep in mind ....the LTA has a nasty rising response... like 5 + db or so starting just above 1K.. and one way other you have to deal with that...."
from ron brady
"Hi Bob---Freddy created an intro for me so how could I not respond. I have created my own version of the "Afterburner Project". It is inspired by John Wyckoff's Hammer Dynamics Super 12 speakers using the eminence beta 12lta driver. The super 12 is a customized version of the 12lta using parts provided by eminence for Hammer Dynamics. Because the 12lta has different t/s parameters a different enclosure was used. I used a 5.1 cu. ft. MLTL design to mate with the 12lta. The speakers produce plenty of deep bass and good slam if you have enough power to drive them. They quit at about 10kHz so a supertweeter is needed and because of a 6db rising response at about 3kHz a parallel notch filter is required. Without the notch filter I can guarantee you that you would not like the driver very much-- it is much too shouty. The enclosures are big and quite heavy but they are about as small as you can go with this driver and still have good performance to about 35Hz. Finished spl is about 95-96. They have a very nice midrange and do well with vocals and they have plenty of weight for large orchestrals. I listen mostly to rock and pop music and they do this genre quite well. The human voice is probably the most difficult sounds to reproduce and the 12lt will faithfully reproduce them if the above mentioned mods and eq are installed. If you don't want to design and build your own system you may want to look at Hammer Dynamics. I believe that they are still being sold. I would be happy to send you a copy of my design if you are serious about it. Send me an e-mail if you are.
Good luck with your search.
ron brady"
but I also read "Fostex's own FT17H horn tweeter left me cold; it measures well, but lacks speed and resolution." on the review of the The BassZilla Leopard: Open Baffle.
Norman
but I remember someone comparing it to the 8" pioneer b20 "cut from the same cloth" very similar sound.
"Eminence made probably at least a dozend versions of the 12" Dual Cone since the 1980's and many before. I used to use earlier versions in Floor Wedge monitors, where they did fine when combined with a tweeter."
"12LT already shows nearly +6db boost to start with and a very ragged frequency response. "
"dunno -- Eminence 12LTA sounds "cleaner" in vocal region than some 8" - but I usually have some sort of box/pipe which is adding coloration reflections back to cone and out vent."
Maybe you should do the afterburner design, seems many like it.
"The Beta 12LTA can make a very, very good midrange on OB."
"and keep in mind ....the LTA has a nasty rising response... like 5 + db or so starting just above 1K.. and one way other you have to deal with that...."
from ron brady
"Hi Bob---Freddy created an intro for me so how could I not respond. I have created my own version of the "Afterburner Project". It is inspired by John Wyckoff's Hammer Dynamics Super 12 speakers using the eminence beta 12lta driver. The super 12 is a customized version of the 12lta using parts provided by eminence for Hammer Dynamics. Because the 12lta has different t/s parameters a different enclosure was used. I used a 5.1 cu. ft. MLTL design to mate with the 12lta. The speakers produce plenty of deep bass and good slam if you have enough power to drive them. They quit at about 10kHz so a supertweeter is needed and because of a 6db rising response at about 3kHz a parallel notch filter is required. Without the notch filter I can guarantee you that you would not like the driver very much-- it is much too shouty. The enclosures are big and quite heavy but they are about as small as you can go with this driver and still have good performance to about 35Hz. Finished spl is about 95-96. They have a very nice midrange and do well with vocals and they have plenty of weight for large orchestrals. I listen mostly to rock and pop music and they do this genre quite well. The human voice is probably the most difficult sounds to reproduce and the 12lt will faithfully reproduce them if the above mentioned mods and eq are installed. If you don't want to design and build your own system you may want to look at Hammer Dynamics. I believe that they are still being sold. I would be happy to send you a copy of my design if you are serious about it. Send me an e-mail if you are.
Good luck with your search.
ron brady"
but I also read "Fostex's own FT17H horn tweeter left me cold; it measures well, but lacks speed and resolution." on the review of the The BassZilla Leopard: Open Baffle.
Norman
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.