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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Karl Avila on February 03, 2012, 09:56:17 am

Title: EV T18 subs
Post by: Karl Avila on February 03, 2012, 09:56:17 am
I just got some of these subs used and noticed in all the pics that the speaker magnets face out. Mine aren't like that. They are facing down. They sound awesome but was there some made this way or do you think they may have have been changed? Also should I turn them back around the way I see in the pics?
Title: Re: EV T18 subs
Post by: Ivan Beaver on February 03, 2012, 11:55:43 am
I just got some of these subs used and noticed in all the pics that the speaker magnets face out. Mine aren't like that. They are facing down. They sound awesome but was there some made this way or do you think they may have have been changed? Also should I turn them back around the way I see in the pics?
If they are used, I would think that somebody "thought" the drivers should be the other way-so they changed it.

I would go with the way they were designed.
Title: Re: EV T18 subs
Post by: Iain.Macdonald on February 04, 2012, 11:27:20 am
I just got some of these subs used and noticed in all the pics that the speaker magnets face out. Mine aren't like that. They are facing down. They sound awesome but was there some made this way or do you think they may have have been changed? Also should I turn them back around the way I see in the pics?

Karl,

The driver should be magnet out. Otherwise you are changing the volume of the rear chamber. Are these genuine, or are they copies like these ones (http://www.nrgrecording.de/html/t18.html). Is the driver a real 18MT? If it isn't, that could be the reason for the non standard orientation. Check the data sheet pdf (http://www.electrovoice.com/downloadfile.php?i=1780) on the EV web site.

Iain.
Title: Re: EV T18 subs
Post by: Paul G. OBrien on February 04, 2012, 12:11:55 pm
Box response changes slightly with the two driver orientations, a little more extension with one and a little more midband gain with the other. That said these boxes are hardly "subs" by todays standards with a response that falls off the cliff at 50hz and is anything but flat from there up so the rated -3db point of 45hz is creative writing at it's best. If these cabs are reproductions and you don't have original DL18MT drivers consider your lucky because some of these copies work better and just about any driver built in the last 20yrs is an improvement over the original EV.
Title: Re: EV T18 subs
Post by: Karl Avila on February 05, 2012, 11:10:51 am
Ok, I am going to open them up. How will if I know if these are genuine mt's? And if they are not, should I still reverse the speakers with the magnet out?

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Title: Re: EV T18 subs
Post by: Karl Avila on February 05, 2012, 09:51:33 pm
I opened them up and the speaker says JBL and a sticker that says 88k-JBE on them. I tried googling them but nothing comes up. I flipped them around but now am curious what speakers these are. What are the original ones that  came with?

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Title: Re: EV T18 subs
Post by: Karl Avila on February 05, 2012, 10:19:24 pm
Ok, maybe I dont know how to read the speakers right cuz the other one says jbl with a sricker that says 98t-jbe. The only markings that both have is stamped 3 06 108. Any clues?

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Title: Re: EV T18 subs
Post by: Nick Enright on February 05, 2012, 11:37:52 pm
Ok, maybe I dont know how to read the speakers right cuz the other one says jbl with a sricker that says 98t-jbe. The only markings that both have is stamped 3 06 108. Any clues?

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photos please...

most definately the EV-t18 did not come with JBL drivers.
Title: Re: EV T18 subs
Post by: Paul G. OBrien on February 06, 2012, 11:27:50 pm
EV also made a sub called the SH1800 which looks just like the T18 except that the driver is mounted "normally"...

Title: Re: EV T18 subs
Post by: Karl Avila on February 07, 2012, 05:36:47 pm
They dont look like those. We play tonight so I will post pics of the speakers in the next day or so when I open them up again.

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Title: Re: EV T18 subs
Post by: Chris Carpenter on March 22, 2012, 04:54:17 pm
They dont look like those. We play tonight so I will post pics of the speakers in the next day or so when I open them up again.
While we're waiting, you reminded me of something I've always wondered. On the magnet-out speakers, what stops audience members from poking the driver cone during shows? Is their a grill on the frame?
Title: Re: EV T18 subs
Post by: Paul G. OBrien on March 22, 2012, 10:27:04 pm
While we're waiting, you reminded me of something I've always wondered. On the magnet-out speakers, what stops audience members from poking the driver cone during shows? Is their a grill on the frame?

The cabinet should have a grill covering the "horn mouth" area.

Title: Re: EV T18 subs
Post by: Chris Carpenter on March 23, 2012, 03:33:52 pm
The cabinet should have a grill covering the "horn mouth" area.
Ah, well, there's that.
Title: Re: EV T18 subs
Post by: Rory Buszka on April 29, 2012, 05:45:42 pm
Box response changes slightly with the two driver orientations, a little more extension with one and a little more midband gain with the other. That said these boxes are hardly "subs" by todays standards with a response that falls off the cliff at 50hz and is anything but flat from there up so the rated -3db point of 45hz is creative writing at it's best. If these cabs are reproductions and you don't have original DL18MT drivers consider your lucky because some of these copies work better and just about any driver built in the last 20yrs is an improvement over the original EV.

These subs are an interesting case. If you can find a driver with a very large and powerful motor structure and load it into your T18, you can then use DSP and powerful amplification to overcome one of the common problems with conventional low-tuned reflex boxes, which is that cone excursion is at a maximum about half an octave above the tuning frequency of the box. In the case of the T18, just above the tuning frequency of the reflex loading is the efficient range of the horn itself, and that helps cut down on the cone excursion, but the horn loading is also more efficient than the reflex loading, which leads to the very distinct character of these boxes. If you use DSP to linearize the response of the enclosure and then provide an HPF just below the tuning frequency, the cone excursion stays low over the entire low-frequency passband. The trouble is the EV driver probably isn't up to the task, so you'd need to practically re-engineer the thing in order to find another suitable driver to try in this experiment.

The EV Phoenix PX2181 subs use the same loading principle, but it looks like they're using stronger drivers so there isn't quite as pronounced of a midbass 'bump' in the response curve, and they may also have a larger chamber volume to boost efficiency at the low end. I've heard the Phoenix subs and they weren't bad at all.
Title: Re: EV T18 subs
Post by: Marc Platt on June 08, 2012, 09:34:39 am
These subs are an interesting case. If you can find a driver with a very large and powerful motor structure and load it into your T18, you can then use DSP and powerful amplification to overcome one of the common problems with conventional low-tuned reflex boxes, which is that cone excursion is at a maximum about half an octave above the tuning frequency of the box. In the case of the T18, just above the tuning frequency of the reflex loading is the efficient range of the horn itself, and that helps cut down on the cone excursion, but the horn loading is also more efficient than the reflex loading, which leads to the very distinct character of these boxes. If you use DSP to linearize the response of the enclosure and then provide an HPF just below the tuning frequency, the cone excursion stays low over the entire low-frequency passband. The trouble is the EV driver probably isn't up to the task, so you'd need to practically re-engineer the thing in order to find another suitable driver to try in this experiment.
I have several T18's and I have some experience with different driver loading in the T18.
 When I first bought 4x t18's used a long time ago, 2 came loaded w/orig drivers, 2 had Peavey BW Low Riders installed.
 I replaced the BW's with OEM ev's and after an EV "jumped the Gap" (blew out) I temporarily put a BW in place.
 This led to an "A/B session" with the EV vs Peavey and to my surprise the peavey sounded better all around and took more pwr.
 I ended up using Black Widow Peaveys (replaced evs as they went) for several years with great success and I never   once had a peavey fail.
  This was a "pot luck" kind of thing and it went my way.
 Eventually I had some Evx180B drivers fall in my lap and that is what I have in them to this day.
  The EVX180 is the driver to have for the T18's and I have used them in my T's for a few yrs and never a failure. They seem to like some power though.
  I have never heard a single 18 FL sub that will compare to the T18's w/evx180
 
Title: Re: EV T18 subs
Post by: Marc Platt on June 08, 2012, 10:10:46 am
I just got some of these subs used and noticed in all the pics that the speaker magnets face out. Mine aren't like that. They are facing down. They sound awesome but was there some made this way or do you think they may have have been changed? Also should I turn them back around the way I see in the pics?
When you turn them (if you decide to) important note, when the drivers are mounted magnet out, the driver should be wired reverse so that positive voltage applied to the red or + terminal shall move the cone away from the box which means your jack plate "+" will be wired to the Black speaker terminal and "-" will be wired to the red.
Title: Re: EV T18 subs
Post by: eric wong on June 23, 2012, 02:56:12 pm
I have several T18's and I have some experience with different driver loading in the T18.
 When I first bought 4x t18's used a long time ago, 2 came loaded w/orig drivers, 2 had Peavey BW Low Riders installed.
 I replaced the BW's with OEM ev's and after an EV "jumped the Gap" (blew out) I temporarily put a BW in place.
 This led to an "A/B session" with the EV vs Peavey and to my surprise the peavey sounded better all around and took more pwr.
 I ended up using Black Widow Peaveys (replaced evs as they went) for several years with great success and I never   once had a peavey fail.
  This was a "pot luck" kind of thing and it went my way.
 Eventually I had some Evx180B drivers fall in my lap and that is what I have in them to this day.
  The EVX180 is the driver to have for the T18's and I have used them in my T's for a few yrs and never a failure. They seem to like some power though.
  I have never heard a single 18 FL sub that will compare to the T18's w/evx180
 

There was an EV "subscoop" single 18" sub with the EVX180B- it's called the Sb180. I got these when a local music chain went out of business almost 10 years ago and still use them to this day. I don't think they were too popular as I hardly hear about them. They have great frequency response and extension (-3 dB at 40 Hz, -10 at 31 Hz) and so far haven't blown up, though admittedly I don't use them at high volumes too often. They're fairly compact too. Just had to cross them over <100 Hz to avoid their mid-bass boom from the cabinet design.

Remember the "double" version of the T18 was the MTL1 (DL18MT loaded) and the MTL1x (EVX180B loaded)? The MTL1x's low frequency response was quite limited (-3dB at 52 Hz and -10 at 45) compared to the sb180.

(http://www.durc.com.mx/data/images/2150_11.JPG)

Title: Re: EV T18 subs
Post by: Marc Platt on June 24, 2012, 08:31:44 pm
There was an EV "subscoop" single 18" sub with the EVX180B- it's called the Sb180. I got these when a local music chain went out of business almost 10 years ago and still use them to this day. I don't think they were too popular as I hardly hear about them. They have great frequency response and extension (-3 dB at 40 Hz, -10 at 31 Hz) and so far haven't blown up, though admittedly I don't use them at high volumes too often. They're fairly compact too. Just had to cross them over <100 Hz to avoid their mid-bass boom from the cabinet design.

Remember the "double" version of the T18 was the MTL1 (DL18MT loaded) and the MTL1x (EVX180B loaded)? The MTL1x's low frequency response was quite limited (-3dB at 52 Hz and -10 at 45) compared to the sb180.

(http://www.durc.com.mx/data/images/2150_11.JPG)
The mtl1x's I used yrs ago would put a serious hurtin on the sb180's but obviously thats not a fair comparison being a double18 and all.