Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Mark Wilkinson]

So my real question from all of this: do I keep my iTech 8000s and SRX728s ?
I am currently debating between buying another pair of 728s ....
I currently have 4 SRX728s and 3 iTech 8000s so I could easily add another pair of subs off of the 3rd iTech.

That's what I'd do, for sure....too easy and low $ vs cost of a lateral change...
I could see a jump to TH-118's or Orbit Shifters or something in that vein, but why spend very much money for any move less than that..

Here's a good review of the 800 series, that you'll need to put in google translate..http://www.production-partner.de/test/jbl-srx-800-im-test/
It's mostly about the 835 and 815, but it does provide some info about the 828..


edited for more clarity

[Andrew Brubaker]

That's what I'd do, for sure....too easy and low $ vs cost of a lateral change...
I could see a jump to TH-118's or Orbit Shifters or something in that vein, but why spend very much money for any move less than that..

Here's a good review of the 800 series, that you'll need to put in google translate..http://www.production-partner.de/test/jbl-srx-800-im-test/
It's mostly about the 835 and 815, but it does provide some info about the 828..


edited for more clarity

Thanks Art and Mark! I agree that I will probably just stick to the 728s and just add more.
Now to get the limiter settings dialed in! If anyone has any advice here, I would be very grateful. I've been reading a lot on the subject and scoured the Internet quite a bit and all I seem to find is conflicting information. I have even contacted JBL Pro and Crown to no avail. The person at JBL Pro gave me peak voltage based on the 3200 watt continuous rating and 3.1 min ohm and the outcome was very different than what was previously mentioned in this post and also was different than a post I found on a crown forum where the peak voltage was 140v (which would put peak wattage at 4900 if I am correct). I also found another Crown tech saying it should be 113v. Crown tech support has yet to contact me back from posts on their site and submitting contact forms. The same forum showed that the RMS limiter should be set to 400watts which doesn't make sense to me if the actual continuous rating is 1600watts. Another thing I am shaky on is the attack and release time for both peak voltage and RMS. Clearly I have a lot to learn. Any wisdom/clarification on the subject would be much appreciated.

[Ivan Beaver]

Thanks Art and Mark! I agree that I will probably just stick to the 728s and just add more.
Now to get the limiter settings dialed in! If anyone has any advice here, I would be very grateful. I've been reading a lot on the subject and scoured the Internet quite a bit and all I seem to find is conflicting information. I have even contacted JBL Pro and Crown to no avail. The person at JBL Pro gave me peak voltage based on the 3200 watt continuous rating and 3.1 min ohm and the outcome was very different than what was previously mentioned in this post and also was different than a post I found on a crown forum where the peak voltage was 140v (which would put peak wattage at 4900 if I am correct). I also found another Crown tech saying it should be 113v. Crown tech support has yet to contact me back from posts on their site and submitting contact forms. The same forum showed that the RMS limiter should be set to 400watts which doesn't make sense to me if the actual continuous rating is 1600watts. Another thing I am shaky on is the attack and release time for both peak voltage and RMS. Clearly I have a lot to learn. Any wisdom/clarification on the subject would be much appreciated.

There are a number of different "correct" limiter voltages.

Which one depends on how you run the system, type of music, how many limiters you have available, what parameter are available within the limiters etc.

Some times setting it for 1/4 continuous power is wise.  Other time setting it 8 times higher (peak power) is correct.

There is no simple single answer-but rather one that depends on a number of different variables.

Without knowing all the variables, it is nothing but a wild guess as to what would be proper for you.

[Andrew Brubaker]

There are a number of different "correct" limiter voltages.

Which one depends on how you run the system, type of music, how many limiters you have available, what parameter are available within the limiters etc.

Some times setting it for 1/4 continuous power is wise.  Other time setting it 8 times higher (peak power) is correct.

There is no simple single answer-but rather one that depends on a number of different variables.

Without knowing all the variables, it is nothing but a wild guess as to what would be proper for you.

Sorry, Ivan, I thought I had specified more. I am using Crown iTech 8000s (so limiters are peak voltage and RMS with attack and release times on each). Running 1 amp per 2 subs at 4ohms a channel. 4 subs total at present. I am either doing live music or EDM at most events these days. The specific event I am gearing up for is an EDM show and I want to make sure that I have my gear set to get the most out of it but also be protected. This will pretty much be my first gig using all 4 subs since having the iTechs and I previously had XTi amps which did not really have limiters worth using. So I am trying to make sure that I have the correct understanding of what I should expect to see from both the amps, speakers and limiters. Not really having used limiters before I am weary of how far to push things and if I am ok running into limit and if I do, how much is ok?

I hope this provides some more needed info! Any help on the subject is much appreciated

[Ivan Beaver]

Sorry, Ivan, I thought I had specified more. I am using Crown iTech 8000s (so limiters are peak voltage and RMS with attack and release times on each). Running 1 amp per 2 subs at 4ohms a channel. 4 subs total at present. I am either doing live music or EDM at most events these days. The specific event I am gearing up for is an EDM show and I want to make sure that I have my gear set to get the most out of it but also be protected. This will pretty much be my first gig using all 4 subs since having the iTechs and I previously had XTi amps which did not really have limiters worth using. So I am trying to make sure that I have the correct understanding of what I should expect to see from both the amps, speakers and limiters. Not really having used limiters before I am weary of how far to push things and if I am ok running into limit and if I do, how much is ok?

I hope this provides some more needed info! Any help on the subject is much appreciated

As a side note-I often respond with questions that may not be specific to the particular question, but rather so that others might learn as well and get a better understanding to their systems, which might be different than the actual system in question.

This forum is about learning and sharing information as well as getting specific answers.  At least I feel that way.


Anyway, Since you are using all Harmon gear-why no use their presets?  I would think that would be a good starting point.

But based on your answers, I would set the thermal limiter to around 1/4 to 1/3rd the continuous rated power.

I would set the continuous limiter for the continuous rated power.  This is not the "program" power rating.

The peak is up for debate, but in my opinion, especially with "abusive" music styles, I often set my peak power for either the limit of the amp or the program rating of the loudspeaker-whichever is lower.

The extra 3dB that you could possibly get is simply not noticeable and the average "event goer" will not realize it, but that extra power could put some additional strains on your speakers-not so much in term of power, but rather in terms of excursion.

I believe the Itechs also have a "amp clip eliminator" that is not located in the limiter sections, but rather in the "amp" section or an output block.  I don't remember exactly as it has been awhile since I was inside one.

I would always turn that ON (there are no adjustments-just on or off), no matter what.  The extra dB or so that you might get out of the amp with it off is simply not worth the possible extra distortion that you might get.

I am a firm believer that if any amp offers clip protection, then ALWAYS use it.

It offers one more level of protection.

[Andrew Brubaker]

As a side note-I often respond with questions that may not be specific to the particular question, but rather so that others might learn as well and get a better understanding to their systems, which might be different than the actual system in question.

This forum is about learning and sharing information as well as getting specific answers.  At least I feel that way.


Anyway, Since you are using all Harmon gear-why no use their presets?  I would think that would be a good starting point.

But based on your answers, I would set the thermal limiter to around 1/4 to 1/3rd the continuous rated power.

I would set the continuous limiter for the continuous rated power.  This is not the "program" power rating.

The peak is up for debate, but in my opinion, especially with "abusive" music styles, I often set my peak power for either the limit of the amp or the program rating of the loudspeaker-whichever is lower.

The extra 3dB that you could possibly get is simply not noticeable and the average "event goer" will not realize it, but that extra power could put some additional strains on your speakers-not so much in term of power, but rather in terms of excursion.

I believe the Itechs also have a "amp clip eliminator" that is not located in the limiter sections, but rather in the "amp" section or an output block.  I don't remember exactly as it has been awhile since I was inside one.

I would always turn that ON (there are no adjustments-just on or off), no matter what.  The extra dB or so that you might get out of the amp with it off is simply not worth the possible extra distortion that you might get.

I am a firm believer that if any amp offers clip protection, then ALWAYS use it.

It offers one more level of protection.

Thanks for the info! I didn't realize the iTechs had that clip protection. It is now enabled on all my amps.

As for the presets, I have yet to find a preset that actually includes limiter settings. I have only found tunings from JBL and the support person I spoke with didn't have any info limiter settings and said to contact Crown (whom I have yet to hear from).

I have not seen a thermal limiter in the 8000. Or least not one that can be set.
As for the continuous RMS limiter, I found that having it at 1600 watts (the continuous rating of the speaker) that I wasn't even hitting the limiter section but was clipping the input before the limiter on the output. (I had to put the sensitivity to the +37db if I recall correctly). When I put the RMS limiter to 800watts then it was actually doing some limiting. Am I missing something? Seems like I should be able to get more out of it than that.

I had the peak voltage set to the level I had seen posted on a Crown forum to 140v. From your recommendation it sounds like I should set it to 99.599v.

Attached is a formula I was provided on this forum. According to that, the Vrms is what you recommend for me to set the peak voltage to, correct?

Thanks again for all your wisdom and advice!

[David Sturzenbecher]

I have not seen a thermal limiter in the 8000. Or least not one that can be set.
As for the continuous RMS limiter, I found that having it at 1600 watts (the continuous rating of the speaker) that I wasn't even hitting the limiter section but was clipping the input before the limiter on the output. (I had to put the sensitivity to the +37db if I recall correctly). When I put the RMS limiter to 800watts then it was actually doing some limiting. Am I missing something? Seems like I should be able to get more out of it than that.

If you look closely at the "RMS Power" limiter in the original iTech, you will see that the shortest that the attack time can be set to is 1sec.    That is far too slow for an RMS limiter as talked about on this forum.    A limiter with an attack time of 1 second or longer really falls into the "thermal" limiting realm.

With an itech, it's a ok idea to ignore the peak limiter, as there is a good chance the peak power capability of the speaker is far above what the amp can produce (especially on subs), then place the itechs "peak voltage" limiter to cover what would typically be the RMS limiting functions, and then use the "RMS power" limiter for thermal limiter duties as described above. 

Another note, if you are clipping your amp input before reaching full amplifer output (common with internal amplifier crossovers)  simply add more "bandpass gain".   Don't be afraid to add 10dB or more if needed.

[Ivan Beaver]

 I would set the "long term" limiter (RMS or thermal or whatever it is called) at around 1/3rd the constant power.

I would set the "program or  average or whatever" at the constant power.

Then the peak at the peak-or a little lower.

As David said-don't be afraid to add some gain inside the amp.

I have noticed that often the input overloads before hitting the limiters-especially when used on subs

[Andrew Brubaker]

I would set the "long term" limiter (RMS or thermal or whatever it is called) at around 1/3rd the constant power.

I would set the "program or  average or whatever" at the constant power.

Then the peak at the peak-or a little lower.

As David said-don't be afraid to add some gain inside the amp.

I have noticed that often the input overloads before hitting the limiters-especially when used on subs

Thanks so much for the info! One question I have is if I take David's method of using the peak limiter in the iTech for RMS limiter and the RMS limiter for the thermal limiter, will that affect the actual peak output? (Because then the amp will only be giving 3200 watts max to the sub, right?) Please forgive my ignorance on the subject.

I am attaching a pic of what I believe would be the correct settings based on Ivan and David's info. The only question I now have is what I should be setting the attack and release times to (seeing as I am using the limiters for something differently than maybe initially intended). And what would I set the peak limiter to if I was still using the actual peak voltage of 140v? I have read some documentation from powersoft on limiter settings but am unsure of what to set attack and release time for the different types of limiters. Any help would be much appreciated!

[Ivan Beaver]

Thanks so much for the info! One question I have is if I take David's method of using the peak limiter in the iTech for RMS limiter and the RMS limiter for the thermal limiter, will that affect the actual peak output? (Because then the amp will only be giving 3200 watts max to the sub, right?) Please forgive my ignorance on the subject.

I am attaching a pic of what I believe would be the correct settings based on Ivan and David's info. The only question I now have is what I should be setting the attack and release times to (seeing as I am using the limiters for something differently than maybe initially intended). And what would I set the peak limiter to if I was still using the actual peak voltage of 140v? I have read some documentation from powersoft on limiter settings but am unsure of what to set attack and release time for the different types of limiters. Any help would be much appreciated!

I would use the 1600 watts at the continuous rating-NOT the program rating.

So that would be 80V.  I would also change the attack time to 20-30ms.

Remember that the peaks are generally short, so they will pass before the attack time start to dramatically limit them.

You MUST weigh getting that little extra dB or so out of a cabinet-vs burning them up.

What is most important?

To me-having the cabinet working at the end of the night is MUCH more important than trying to squeeze an extra dB or so out of the cabinet-that NOBODY would every notice.

[ProSoundWeb Community]