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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 => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Ben Lawrence on February 24, 2010, 05:12:42 pm

Title: Beater Sub
Post by: Ben Lawrence on February 24, 2010, 05:12:42 pm
Hello,
I purchased a set of EAW tops and these what appear to be diy made subs as a set. Anyhow the carpet job on them was looking pretty bad so I am just trying to clean them up a bit. They are loaded with EVM 18b drivers which are stamped as 200w@8 ohm. Some of you may be familiar with these. Anyhow I was wondering if it might be worth looking into updating the drivers. I have received some pretty good advice here in the past and am just seeing what a few of you think.

intereior box dimensions.
46"height
22"wide
27"deep

Sorry for the cell phone pic.
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Title: Re: Beater Sub
Post by: Elliot Thompson on February 24, 2010, 10:29:14 pm
The box resembles an old W bin cabinet that someone converted into what appears (the photos are very dark) to be a double eighteen reflex cabinet. The drivers should date back to the late 1970’s to early 1980’s when 200 watts was considered a lot of power.

If the cabinet is still solid, you could replace the drivers and, re-tune the cabinet to achieve optimum performance for whatever woofers you are eyeing.  Only you can determine if the upgrade, or buying possibly a used JBL 728 would be a better investment.

Best Regards,
Title: Re: Beater Sub
Post by: Paul O'Brien on February 24, 2010, 11:16:36 pm
Ben Lawrence wrote on Wed, 24 February 2010 17:12

 They are loaded with EVM 18b drivers which are stamped as 200w@8 ohm. Some of you may be familiar with these. Anyhow I was wondering if it might be worth looking into updating the drivers.


If the cabs are solid then yes newer drivers will make them usefull, the 18b can't even be considered a true "suwoofer" by todays standards so pretty much anything will be an upgrade.

Realistic options would start with PV Lowriders I think, you need this much driver to get something that can actually handle it's rated power, but the Definimax 18LF and B&C TBX series would also be good choices if your budget is a little richer. Stepping up to the JBL drivers doesn't buy you any more power handling or output and the newer EV drivers would actually be a step down so these last two aren't the best value.
Title: Re: Beater Sub
Post by: Ben Lawrence on February 25, 2010, 09:43:55 am
I cant seem to find the PV Lowrider in the drivers listed on WinISD.
Title: Re: Beater Sub
Post by: Paul O'Brien on February 25, 2010, 01:45:08 pm
It's not you will have to add it.
Title: Re: Beater Sub
Post by: Rik Turner on February 25, 2010, 03:26:50 pm
whats the size of the box, inside dims at front lip and depth? looks like something I've seen before but nothing to reference size in the picture
Title: Re: Beater Sub
Post by: Ben Lawrence on February 25, 2010, 03:40:40 pm
I posted the internal dimensions above in my original post. Im not sure what you are referring to the lip. I will take another couple of pics when I get a chance.
Title: Re: Beater Sub
Post by: Gene Hardage on February 27, 2010, 07:38:39 pm
Scrape the carpet off and paint the cabs.
Put some speaker dope goo on the surrounds of the old EV 18s.
Install speakers - fire them up and listen for rattles.
If they work OK use them 'till they blow and if you really like them you can then recone them to the current 400 watt type.
While you're using them save your pennies for something better.
Title: Re: Beater Sub
Post by: Art Welter on February 28, 2010, 03:46:22 pm
Gene Hardage wrote on Sat, 27 February 2010 17:38

Scrape the carpet off and paint the cabs.
Put some speaker dope goo on the surrounds of the old EV 18s.
Install speakers - fire them up and listen for rattles.
If they work OK use them 'till they blow and if you really like them you can then recone them to the current 400 watt type.
While you're using them save your pennies for something better.

The 400 watt voice coil is 3 dB less efficient, a waste of power.
The limitation of the 18B speaker is it has fairly little X max.

That said, if you aren't looking for pant leg fluttering lows, the 18B does a good job.
Title: Re: Beater Sub
Post by: Gene Hardage on February 28, 2010, 10:54:04 pm
Art Welter wrote on Sun, 28 February 2010 15:46

Gene Hardage wrote on Sat, 27 February 2010 17:38

Scrape the carpet off and paint the cabs.
Put some speaker dope goo on the surrounds of the old EV 18s.
Install speakers - fire them up and listen for rattles.
If they work OK use them 'till they blow and if you really like them you can then recone them to the current 400 watt type.
While you're using them save your pennies for something better.

The 400 watt voice coil is 3 dB less efficient, a waste of power.
The limitation of the 18B speaker is it has fairly little X max.

That said, if you aren't looking for pant leg fluttering lows, the 18B does a good job.


Very interesting - my speaker fixer never mentioned that.  He just said that the new cones are rated at 400 watts and presto your old 200 watt frame becomes a new 400 watt speaker.  It's been a long time since my last EV recone and it just happened to be an old 18 that we used the newer 400 watt kit and stuffed it back in the dinosaur EV 1803 cab with the aluminum edging.  Still makes a great keyboard monitor.
Title: Re: Beater Sub
Post by: Ben Lawrence on October 18, 2010, 09:35:53 pm
Ok so these appear to be modified w bins to a reflex bin. I have one stripped of the carpet and cleaned up decent. I am thinking of replacing the EV drivers with Lowriders. Although I just missed a deal on ebay for a lot of 4 for 600$ which Im pretty bummed about. So calculating cubic feet the cabinet appears to be. 46"x 22" x 27" / 1728 = 15.8125. Peavey lists the lowrider as 9 cubic feet for a single sub does this mean a dual sub should run 18 cubic feet. Also I am thinking of running a single rectangular vent in the center of the two drivers as I have seen other manufactureres do. Please advise if you feel inclined thanks. Where is Art Welter that guy knows his stuff.
Title: Re: Beater Sub
Post by: Duncan McLennan on October 18, 2010, 09:55:09 pm
Do you know what the cabinet is tuned to now? Why do you want to change the port, and do you know what effect that will have on the cabinet and the loading of the drivers?

A slightly small cabinet generally means you can't get quite as low. It can also mean the drivers are less likely to get cooked (large box means lots of excursion down low).
Title: Re: Beater Sub
Post by: Ben Lawrence on October 18, 2010, 10:14:07 pm
The front panel was kinda sloppy. Have the thing pretty much pulled apart just trying to tighten it up a bit. I do not know the exact effect of the loading which is why I am posting. I hate cooked drivers but I like to get low. So those Ev drivers were not cutting it. 3.3mm of xmax. It appears more modern subs have double that. I am def not claiming to be a sub master (no pun intended) but twice the xmax has got to push some more air.
Title: Re: Beater Sub
Post by: Art Welter on October 19, 2010, 04:35:56 pm
Ben Lawrence wrote on Mon, 18 October 2010 20:14

The front panel was kinda sloppy. Have the thing pretty much pulled apart just trying to tighten it up a bit. I do not know the exact effect of the loading which is why I am posting. I hate cooked drivers but I like to get low. So those Ev drivers were not cutting it. 3.3mm of xmax. It appears more modern subs have double that. I am def not claiming to be a sub master (no pun intended) but twice the xmax has got to push some more air.

The 9 cubic foot box runs out of Xmax 15% before running out of power.
Technically, you will rip the speakers first in a big box and cook them first in a small box, trying to get the LF the small box does not produce  Laughing .
It is all a continuum, these three alignments show how each "works", but you can choose things "in between".
Just make sure the box is well braced, try to make the ports closer to square (or triangular) rather than thin slots. And check the tuning to make sure it came out like you want it !
index.php/fa/33166/0/

If the old EVM 18s work, I may be interested in them.
I have lots of stuff to trade..

Art Welter
Title: Re: Beater Sub
Post by: Ben Lawrence on October 24, 2010, 08:46:24 pm
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Title: Re: Beater Sub
Post by: Ben Lawrence on October 24, 2010, 08:47:25 pm
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Title: Re: Beater Sub
Post by: Ben Lawrence on October 24, 2010, 08:49:07 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 11:52:36 am
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 11:53:05 am
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 11:53:26 am
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 11:53:55 am
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 11:55:12 am
The Sigma Pro 18 seems to suck in this box. I'd recommend the 40Hz tuning with a steep high pass. It's just not going to be able to do much low end.
Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:04:39 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:05:06 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:05:47 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:07:41 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:08:49 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:10:58 pm
The graphs tell the story here. The Delta Pro 18As offer the best response in the box tuned at 50Hz. With the 50Hz tuning, the box will be about 10dB down at 40Hz, which is usual for many subs.

The Sigma will win in outright output from a power standpoint, but the Delta will win from the sound quality standpoint. Neither goes really that low.

I'm plotting the Definimax now...
Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:18:08 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:18:43 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:19:49 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:22:51 pm
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Title: Re: Beater Sub
Post by: Silas Pradetto on October 25, 2010, 12:25:13 pm
I recommend a pair of Definimax tuned to 46Hz. This gives the lowest F3 of any combination.

Frequency and predicted F3:

43 50.67
44 50.82
45 51.02
46 42.22
47 42.6
48 43.01
49 43.45
50 43.9

Not sure why F3 drops so rapidly after hitting 46Hz...but it looks good on paper, anyway.

Title: Re: Beater Sub
Post by: Duane Silveira on October 26, 2010, 10:13:09 am
Silas, what does the Omega pro18a look like modelled in that same cab?
Title: Re: Beater Sub
Post by: Silas Pradetto on October 26, 2010, 10:30:49 am
Duane Silveira wrote on Tue, 26 October 2010 10:13

Silas, what does the Omega pro18a look like modelled in that same cab?


You're killing me Laughing

I'll see if I have time to plot it today. Any graphs in particular you want to see? I know the Omega drivers are low Xmax.
Title: Re: Beater Sub
Post by: Duane Silveira on October 26, 2010, 08:55:06 pm
My cabs are darn near exactly the same dimensions, i tuned mine to 40hz and dropped in the Omegas. Im happy with the performance, i realize im prob running out of xmax fairly early in relation to the thermal max. Nonetheless it would be nice to see the same plots compared to the deltas and the Sigmas.
Title: Re: Beater Sub
Post by: Silas Pradetto on October 27, 2010, 10:36:17 am
Merry Christmas. The Omega looks very nice in that box.

Unfortunately, at that power, the Omega is about DOUBLE Xmax, so it's not going to sound too good.

I had to bring power into the pair of woofers down to 400W to stay within Xmax.

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Title: Re: Beater Sub
Post by: Silas Pradetto on October 27, 2010, 10:37:52 am
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Title: Re: Beater Sub
Post by: Paul O'Brien on October 27, 2010, 11:16:46 am
The Lowriders produce an F3 of 35hz with a single 4.5" x 20" x 5.25" deep slot port between them(I don't know if there's room for that). I calculate internal volume is about 14.5 cu ft after subtracting the port and driver displacement. 1600w puts them just 1mm over Xmax at 55hz in this configuration and output is over 131db(calculated) from 50hz up. For the cost of these drivers that's outstanding performance.

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Title: Re: Beater Sub
Post by: Paul O'Brien on October 27, 2010, 11:19:12 am
Here's the excursion plot at 1600w with the addition of a 2nd order highpass filter at 30hz.

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Title: Re: Beater Sub
Post by: Silas Pradetto on October 27, 2010, 11:24:34 am
Dude, resize those please.
Title: Re: Beater Sub
Post by: Paul O'Brien on October 28, 2010, 03:26:53 pm
Yeah should have made them a bit smaller.. but can't edit the posts now.
Title: Screen size
Post by: Mac Kerr on October 28, 2010, 03:45:55 pm
Silas Pradetto { wrote on Wed, 27 October 2010 11:24

Dude, resize those please.


Resize what? I just looked at this whole thread in flat view on my laptop and there was not one image that went past the screen edge. What are you looking at them on VGA?

Mac
Title: Re: Screen size
Post by: Silas Pradetto on October 28, 2010, 08:00:04 pm
Mac Kerr wrote on Thu, 28 October 2010 15:45

Silas Pradetto { wrote on Wed, 27 October 2010 11:24

Dude, resize those please.


Resize what? I just looked at this whole thread in flat view on my laptop and there was not one image that went past the screen edge. What are you looking at them on VGA?

Mac



1280x1024 in Firefox beta fullscreen?
Title: Re: Beater Sub
Post by: Dave Junius on October 29, 2010, 07:34:14 am
Ben,
Not to hijack your thread, but how much of a pain was it to de-fuzz those boxes. I have contemplated doing the same with my subs. Also what did you use, lots of elbow grease and a little mineral spirits or toluene I presume.

Thanks,
Dave
Title: Re: Beater Sub
Post by: Ben Lawrence on October 29, 2010, 02:32:36 pm
These cabinets are pretty beat. I just used elbow grease to rip off the carpet and will sand down any remaining glue residue. A well applied carpet might be a little more difficult.