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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: Will Knight on July 15, 2013, 04:54:05 pm

Title: PRX718S vs. PRX 618s XLF
Post by: Will Knight on July 15, 2013, 04:54:05 pm
Hi All,
A couple of quick questions here.  Relatively new to the forum from a posting standpoint although I've been following ProSoundWeb for over a year now (Fantastic advice and commentary regardless of the subject).

I have 1 PRX 718S, brand new, never used for a gig, show etc.  Only had it "out for a walk" once to test it with my mains (got it last summer).
I have been looking for another one - expecting to be used but ever so slightly (certainly not one from a DJ) - so I can run, depending on the need 1 or 2 identical subs.

Given availability is scarce to say the least, would it more appropriate to:

a) sell the P718S and get 2 P618x Xlf's
or
b) get 1 618s-xlf and use both. 

Since they are practically the same driver (2268 FF vs. H) and have essentially the same capability from a bandwidth and power standpoint, I would imagine going the b) route would be feasible but not necessarily the best, long term path to take.

While I can readily afford option a) it's a matter of doing it now vs. later. 

Note, I'm not in a hurry to make the move.

Thanks

Bill
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Tim Weaver on July 15, 2013, 05:27:09 pm
Hi All,
A couple of quick questions here.  Relatively new to the forum from a posting standpoint although I've been following ProSoundWeb for over a year now (Fantastic advice and commentary regardless of the subject).

I have 1 PRX 718S, brand new, never used for a gig, show etc.  Only had it "out for a walk" once to test it with my mains (got it last summer).
I have been looking for another one - expecting to be used but ever so slightly (certainly not one from a DJ) - so I can run, depending on the need 1 or 2 identical subs.

Given availability is scarce to say the least, would it more appropriate to:

a) sell the P718S and get 2 P618x Xlf's
or
b) get 1 618s-xlf and use both. 

Since they are practically the same driver (2268 FF vs. H) and have essentially the same capability from a bandwidth and power standpoint, I would imagine going the b) route would be feasible but not necessarily the best, long term path to take.

While I can readily afford option a) it's a matter of doing it now vs. later. 

Note, I'm not in a hurry to make the move.

Thanks

Bill

I didn't really follow everything in that post, but I guess you are asking whether to get the 618 vs the XLF? Go with the XLF for sure. There is no comparison really. the 618 is kind of a wimp.

Also, they don't really play well together. If you had one of each, you would end up either A) effectively using the XLF by itself because the 618 can not contribute enough to couple effectively, or B) turning the XLF down to match the performance of the 618, in which case, why pay the extra money for the XLF.
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Will Knight on July 15, 2013, 08:40:41 pm
I didn't really follow everything in that post, but I guess you are asking whether to get the 618 vs the XLF? Go with the XLF for sure. There is no comparison really. the 618 is kind of a wimp.

Also, they don't really play well together. If you had one of each, you would end up either A) effectively using the XLF by itself because the 618 can not contribute enough to couple effectively, or B) turning the XLF down to match the performance of the 618, in which case, why pay the extra money for the XLF.

Thanks Tim for your comment.  More specifically though is understanding whether it makes sense to have 1 PRX 618s-xlf perform with 1 PRX 718s.

Would there be any issue with the above combination vs. 2 of PRX 718s (hard to find) vs. 2 618s-xlf?

Alternatively, I've come across an excellent pair of SRX718s subs (2) and wondered if it was more beneficial longer term to go with an all SRX platform vs. the PRX series...
BTW, my tops currently are passive M515's pushed by a QSC GX7..

Thanks

Bill
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Jonathan Ladner on July 16, 2013, 03:46:38 pm
Hi All,
A couple of quick questions here.  Relatively new to the forum from a posting standpoint although I've been following ProSoundWeb for over a year now (Fantastic advice and commentary regardless of the subject).

I have 1 PRX 718S, brand new, never used for a gig, show etc.  Only had it "out for a walk" once to test it with my mains (got it last summer).
I have been looking for another one - expecting to be used but ever so slightly (certainly not one from a DJ) - so I can run, depending on the need 1 or 2 identical subs.

Given availability is scarce to say the least, would it more appropriate to:

a) sell the P718S and get 2 P618x Xlf's
or
b) get 1 618s-xlf and use both. 

Since they are practically the same driver (2268 FF vs. H) and have essentially the same capability from a bandwidth and power standpoint, I would imagine going the b) route would be feasible but not necessarily the best, long term path to take.

While I can readily afford option a) it's a matter of doing it now vs. later. 

Note, I'm not in a hurry to make the move.

Thanks

Bill

I have 2 PRX 718s and have been very satisfied with them.  Luckily, I was able to buy the second one about the same time they introduced the 618xlf series and discontinued the prx718s (less than a year in production it seems).  Since they use the same driver, I would think they pair well together with the crossover point being the only exception.  The 618xlf is 90hz where the 718s is 120hz.  If you are using external crossover, this may not be a concern.

Jonathan
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Will Knight on July 16, 2013, 03:59:37 pm
I have 2 PRX 718s and have been very satisfied with them.  Luckily, I was able to buy the second one about the same time they introduced the 618xlf series and discontinued the prx718s (less than a year in production it seems).  Since they use the same driver, I would think they pair well together with the crossover point being the only exception.  The 618xlf is 90hz where the 718s is 120hz.  If you are using external crossover, this may not be a concern.

Jonathan

Jonathan,
I kinda thought would have been the only real issue.  I use a DRPA and will set XOVR at around 90hz due to the tops.

In the meantime, will continue to look out of a PRX718s.  The one I have is awesome just by itself...but I'm comparing that one to 2 MRX500 subs...
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Jonathan Ladner on July 16, 2013, 04:10:00 pm
Jonathan,
I kinda thought would have been the only real issue.  I use a DRPA and will set XOVR at around 90hz due to the tops.

In the meantime, will continue to look out of a PRX718s.  The one I have is awesome just by itself...but I'm comparing that one to 2 MRX500 subs...

I use a DRPA with mine as well; 120hz is too high and robs the sub of headroom for any "real" low end IMHO.  Since I am using prx515 for tops, I decided to dial my crossover at 80hz.  Been very happy with the results.

Good luck on finding a sibling to your sub... :D
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Cailen Waddell on July 16, 2013, 11:23:31 pm
Also don't forget the prx 600 series has been discontinued by JBL. Stock is limited to what dealers and distributors have on hand with the exception of the 625 I believe....  Doesn't make the 618  xlf any less of a cabinet, but you may not have the option to buy one now and one later.....
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Reggie Kendrick on July 28, 2013, 10:34:27 am
Also don't forget the prx 600 series has been discontinued by JBL. Stock is limited to what dealers and distributors have on hand with the exception of the 625 I believe....  Doesn't make the 618  xlf any less of a cabinet, but you may not have the option to buy one now and one later.....
Go with the new PRX718XLF.  It's only 1/2 lb heavier.
Title: Re: PRX718S vs. PRX 618s XLF
Post by: George Friedman-Jimenez on July 28, 2013, 11:50:46 am
Jonathan,
I kinda thought would have been the only real issue.  I use a DRPA and will set XOVR at around 90hz due to the tops.

In the meantime, will continue to look out of a PRX718s.  The one I have is awesome just by itself...but I'm comparing that one to 2 MRX500 subs...

The PRX618-XLF has a non-defeatable low pass filter at 90 Hz and needs to be fed full range signal, not signal that has already been low passed at 90 or 120. The sub is designed to receive full range signal, then it outputs a signal that is high passed at 90 Hz for the tops.

Not only don't you need an external crossover, using one for the subwoofer signal would put 2 LP filters in tandem and leave a big hole in the 80-100 Hz range. Not sure if the PRX718S crossover is defeatable, but it may be difficult to use 2 subs with different crossover frequencies in one system.
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Jonathan Ladner on July 28, 2013, 03:35:06 pm
The PRX618-XLF has a non-defeatable low pass filter at 90 Hz and needs to be fed full range signal, not signal that has already been low passed at 90 or 120. The sub is designed to receive full range signal, then it outputs a signal that is high passed at 90 Hz for the tops.

Not only don't you need an external crossover, using one for the subwoofer signal would put 2 LP filters in tandem and leave a big hole in the 80-100 Hz range. Not sure if the PRX718S crossover is defeatable, but it may be difficult to use 2 subs with different crossover frequencies in one system.

I use an external crossover to lower the crossover point from 120 to 80 on the 718s. 120 is too high when using with 15 tops. If one would need to move the crossover low pass point higher than 120, it would not be possible. It is not defeatable without a modification. Only the crossover output is defeatable to full range.
Title: Re: PRX718S vs. PRX 618s XLF
Post by: Tim Padrick on August 05, 2013, 01:42:58 am
There's a guy in Indy with:

2 Each JBL PRX 618s-XLF Powered Subwoofers
2 Each JBL SS4-BK Speaker Pole with Protective Sleeve
2 Each JBL Bags PRX618SXLF-CVR Padded Covers
$1850  Call or txt Brian @ 317-seven three zero-1315