How I came to this point is a bit of a long story but I really want to make the best of my Eminence Beta 12LTA using an existing enclosure.
What do I have so far?
- A brand new pair of Eminence Beta 12LTA 8Ohms (no filter)
- I have a 114-litre enclosure with a single port 10.3cm diameter and 2.14cm (ish) length, which gives 83.32cm2.This port length came from an online calculator; the port diameter was already there.
- The enclosure is lined with 1.2 cm of felt (except for the baffle)
- As a tweeter I use a Philips RT8 band (circular)tweeter with a 2,2uF capacitor, I used a smaller value (1.0 / 1.5) at the start but I really thought the sound was missing something (gap?).
How does it sound?
It sounds beyond expectation! There is a lot of sound. There are nice highs and surprising lows and I like the “Live” sound. But if I am being critical it sometimes sounds a bit hollow in the mid’s and low’s. And although there is a lot of sound in the low section it sometimes lacks of pressure (I hope that is a right assumption).
What are the worries?
In the Eminence design sheet I see the use of a 30Hz Highpass filter. On the Internet I see a lot of different passive filtering going on and a lot people use DSP (which I don’t have) to control this driver.
What do I hope for?
Nirvana would be nice… ☺ but if someone says “this is it” that would also be fine but a “simple/cheap” tweak to bring this driver in this setting to a slightly higher/next level would be very nice.
R
What do I have so far?
- A brand new pair of Eminence Beta 12LTA 8Ohms (no filter)
- I have a 114-litre enclosure with a single port 10.3cm diameter and 2.14cm (ish) length, which gives 83.32cm2.This port length came from an online calculator; the port diameter was already there.
- The enclosure is lined with 1.2 cm of felt (except for the baffle)
- As a tweeter I use a Philips RT8 band (circular)tweeter with a 2,2uF capacitor, I used a smaller value (1.0 / 1.5) at the start but I really thought the sound was missing something (gap?).
How does it sound?
It sounds beyond expectation! There is a lot of sound. There are nice highs and surprising lows and I like the “Live” sound. But if I am being critical it sometimes sounds a bit hollow in the mid’s and low’s. And although there is a lot of sound in the low section it sometimes lacks of pressure (I hope that is a right assumption).
What are the worries?
In the Eminence design sheet I see the use of a 30Hz Highpass filter. On the Internet I see a lot of different passive filtering going on and a lot people use DSP (which I don’t have) to control this driver.
What do I hope for?
Nirvana would be nice… ☺ but if someone says “this is it” that would also be fine but a “simple/cheap” tweak to bring this driver in this setting to a slightly higher/next level would be very nice.
R
as long as the enclosure is tuned "just right" to your ears - not weak - not bloated in the upper bass with the music you enjoy, then that seems pretty reasonable and a ribbon tweeter a good thing.
You can experiment with damping material placement. The classic way for a reflex would be to have the damping on just three walls - such as one sidewall, the bottom, and the back panel. You might play with a small bypass capacitor across the 2uF tweeter cap. With the tweeter being a ribbon, you don\t have the potential nasty interaction of varying input inpedance.
adding bracing to the cabinet - if needed can sometimes help things.
if not intending to ever sell or trade the drivers, then you might experiment with damping the steel basket
with typical foil backed car damping or sticky roofing material - -I don't know how that might affect the way 12LTA sounds. Its basket
isn't as thin as say a Nirvana. Some steel baskets are better than some cast.
there's cone treatments - somewhat controversial and subjective in outcome. Bastanis used small round felt pads on his Emiennce
speakers. Planet10 experimented for years and settled on the Enabl method. A thinned Modpodge coat alone will alter things. If nothing else, it makes a thin paper cone less likely to rip if something pokes it.
re:30Hz highpass filter - can\t imagine needing that in home use even with 12LTA on en open baffle. That would be so called pro-use, 12LTA is barely a "pro" driver. If you see the cone moving more than 1/4" peak to peak then its probably running out of steam. I think the physical overhang for the voice coil on 12LTA is 0.08 inches despite a large rated xmax, so it tends to sound compressed or lacking "kick" vs a speaker with more xmax with BL reasonably constant.
some folks remove the dustcap and put a so-called "phase plug" on the pole piece. That can remove a cavity resonance between the pole piece and dustcap but don\t know if really worth the hassle.
I think the "helper tweeter" is a prime determiner of how well 12LTA is perceived. For myself, the old Selenium slot loaded tweeters with wide horizontal dispersion work.
Here's an image that was once on Photobucket - the damping pads are large so might give an idea how one 12LTA user tweaked their speaker -- is that weather stripping? what does it look like to you guyz?
AH - "Legis" is the one who did this mod and it successfully tamed a 2K5 peak - so its worth asking him about the damping material
http://www.diyaudio.com/forums/full-range/179161-beta-12lta-3cf-box-port-size-38.html#post3559610
You can experiment with damping material placement. The classic way for a reflex would be to have the damping on just three walls - such as one sidewall, the bottom, and the back panel. You might play with a small bypass capacitor across the 2uF tweeter cap. With the tweeter being a ribbon, you don\t have the potential nasty interaction of varying input inpedance.
adding bracing to the cabinet - if needed can sometimes help things.
if not intending to ever sell or trade the drivers, then you might experiment with damping the steel basket
with typical foil backed car damping or sticky roofing material - -I don't know how that might affect the way 12LTA sounds. Its basket
isn't as thin as say a Nirvana. Some steel baskets are better than some cast.
there's cone treatments - somewhat controversial and subjective in outcome. Bastanis used small round felt pads on his Emiennce
speakers. Planet10 experimented for years and settled on the Enabl method. A thinned Modpodge coat alone will alter things. If nothing else, it makes a thin paper cone less likely to rip if something pokes it.
re:30Hz highpass filter - can\t imagine needing that in home use even with 12LTA on en open baffle. That would be so called pro-use, 12LTA is barely a "pro" driver. If you see the cone moving more than 1/4" peak to peak then its probably running out of steam. I think the physical overhang for the voice coil on 12LTA is 0.08 inches despite a large rated xmax, so it tends to sound compressed or lacking "kick" vs a speaker with more xmax with BL reasonably constant.
some folks remove the dustcap and put a so-called "phase plug" on the pole piece. That can remove a cavity resonance between the pole piece and dustcap but don\t know if really worth the hassle.
I think the "helper tweeter" is a prime determiner of how well 12LTA is perceived. For myself, the old Selenium slot loaded tweeters with wide horizontal dispersion work.
Here's an image that was once on Photobucket - the damping pads are large so might give an idea how one 12LTA user tweaked their speaker -- is that weather stripping? what does it look like to you guyz?
AH - "Legis" is the one who did this mod and it successfully tamed a 2K5 peak - so its worth asking him about the damping material
http://www.diyaudio.com/forums/full-range/179161-beta-12lta-3cf-box-port-size-38.html#post3559610
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The Eminence 12lta is a really nice wide range driver. Here's my take on improving it.
https://speakerprojects.wordpress.com/2016/08/29/eminence-beta-12lta-on-open-baffle/
https://speakerprojects.wordpress.com/2016/08/29/eminence-beta-12lta-on-open-baffle/
It's the Eminence 1001 and this horn.
Dayton Audio H45E 4.5" x 4.5" Elliptical Waveguide 1-3/8"- 18 TPI
I'm just using a cap on the tweeter (1.5uf I think - certainly something close). Try a few different ones and keep us posted if you do. Upon critical listening, the tweeter might like a bit of an upward lift. Maybe an L-pad?
Dayton Audio H45E 4.5" x 4.5" Elliptical Waveguide 1-3/8"- 18 TPI
I'm just using a cap on the tweeter (1.5uf I think - certainly something close). Try a few different ones and keep us posted if you do. Upon critical listening, the tweeter might like a bit of an upward lift. Maybe an L-pad?
Zilla,
I have red your page many times. And I was tempted to go open baffle, I will certainly try that in the (near) future. But I really wanted to use this enclosure (I like the looks). When I have gathered all my nerves I will remove the dust cap!.
In the meanwhile I have added the damping mentioned earlier, I did not had the time to listen carefully.
R.
I have red your page many times. And I was tempted to go open baffle, I will certainly try that in the (near) future. But I really wanted to use this enclosure (I like the looks). When I have gathered all my nerves I will remove the dust cap!.
In the meanwhile I have added the damping mentioned earlier, I did not had the time to listen carefully.
R.
i might be late to the party but i have a very similar set up and i cant tell you how happy i am. For the tweeter though i used a super tweeter (Realistic Super Tweeter 40-1310). The super tweets just blend so well and create just a mesmerizing impact. Love the setup, just doesnt have the form and the WAF for the living room. Had to go with SL's Lxmini to get anything closer from an imaging and dynamics perspective. If any one is on the edge, just do it, you will be hard pressed to hear something better for even 10k
Hey everyone, just FYI - the BETA 12LTA is back:
SA Beta-12LTA 12 Inch full Range Woofer Speaker for DIY Infinite Baffl – SpeakerAddict
SA Beta-12LTA 12 Inch full Range Woofer Speaker for DIY Infinite Baffl – SpeakerAddict
hi speakas -
if you have contact with Speaker Addict please suggest the idea of marketing a limited run of 12LTA-type (perhaps "Super-12LTA") with a larger magnet (56 oz ballpark should work w/o serious re-workting) to lower qts and allow operation in smaller reflex and BLH. The engineers at Eminence should be able to make some tradeoffs to have a good sounding product and perhaps sell to the public for around "$100" each. An extra 2mm of coil height might help with dynamic compression issues of the stock model. (? - Eminence can model it for sure)
if you have contact with Speaker Addict please suggest the idea of marketing a limited run of 12LTA-type (perhaps "Super-12LTA") with a larger magnet (56 oz ballpark should work w/o serious re-workting) to lower qts and allow operation in smaller reflex and BLH. The engineers at Eminence should be able to make some tradeoffs to have a good sounding product and perhaps sell to the public for around "$100" each. An extra 2mm of coil height might help with dynamic compression issues of the stock model. (? - Eminence can model it for sure)
Not bad, qts close to .4 can be nice.
Copper cap or shorting ring would be nice, but swapping out the magnet for a stronger one, there will be more climb past 1khz..........
Too bad there isn't much demand for a double whizzer driver (fane 250tc).
The hammer 12 kit was nice with the tweet (super?).
Copper cap or shorting ring would be nice, but swapping out the magnet for a stronger one, there will be more climb past 1khz..........
Too bad there isn't much demand for a double whizzer driver (fane 250tc).
The hammer 12 kit was nice with the tweet (super?).
- briefly had.a defective Hammer 12 fullrange - same little magnet (its enough for Beta 8cx) - maybe more refined than 12LTA with a working example(?).
12-250TC is advanced in comparison as goes an octave higher (dead on-axis) - but again, Qes is high.
A rising response is welcomed with my toys
12-250TC is advanced in comparison as goes an octave higher (dead on-axis) - but again, Qes is high.
A rising response is welcomed with my toys
Hi guys, I'm going to be building a pair of big vented cabinets using the beta 12ltas, the Eminence ADS100Ss. I already have a tweeter cap and a notch filter for the 12ltas. What I've been struggling to find is any examples of the cabinets to use as a starting point. I know these speakers are not the best for bass, but from what I've read, they can sound good in the bass arena using a larger ported or vented cabinet. Could someone please point me in the right direction? Thanks... Bob
Hmmmm.......
My take on a mltl is you double the area needed for a standard 4th ported, but it has to be long based on transmission line theory.
I don't think I'm right though.
My 2x15's, i had them in a box half as small as it should be still porting at recommended 4th (30hz), worked fine.
12" full range wide open, you can get nice deep bass, just don't expect overall to be too loud without warbling. .
My take on a mltl is you double the area needed for a standard 4th ported, but it has to be long based on transmission line theory.
I don't think I'm right though.
My 2x15's, i had them in a box half as small as it should be still porting at recommended 4th (30hz), worked fine.
12" full range wide open, you can get nice deep bass, just don't expect overall to be too loud without warbling. .
(Hammer had the same feeble magnet as stock 12LTA) re:88 liter - just something I would build 4ft tall and with Zu style. Dunno if a gaped base would tune to 28Hz but maybe (?)
There was no fill in this pipe so more ripple than would be if properly damped. The bottom of the column is fully open - the full cross sectional area letting the base do the tuning.
There was no fill in this pipe so more ripple than would be if properly damped. The bottom of the column is fully open - the full cross sectional area letting the base do the tuning.
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