Finalizing plans for system upgrade, need input

[akillj]

So if any of you have read my past thread, i've started making plans for upgrading my system. As I previously stated, I do larger events (School dances in gyms). My two LS720P's and Rcf Art 312A's have barely cut it for this, but I get by with what I have.

I'm comfortable with the volume of my Rcf's during these events (Given, they're near-limiting), so I wanted to give them a little headroom and pick up another pair. So I'd be using 4 of them, and they can all have headroom.

As for bass, I wanted to upgrade to two 801P's coupled.

My budget is about $4,000 and I even managed to fit the other accessories into the budget (New Ultimate Support stands for the new tops, more Xlr's ect.)

I feel this is a great way to go with my budget, but as always, I wanted your guys' opinion.

[unsafe8989]

Are you good with wood? How about a DIY? Visit this site --> www.billfitzmaurice.com/

[Al Poulin]

Two pairs of 312As with a pair of 801Ps should work pretty nicely IMO. You will notice a dramatic increase in low frequency going from 720Ps to 801Ps... ;) Two pairs of 312As will certainly give you more coverage.

You could also consider upgrading your tops to some higher output tops such as EV ZX5As, but those are lots of $$$. FBT also makes some kick ass lightweight powered tops with larger exit horns that would help with throw. Even moving up to a set of Yamaha DSR 112s might give you that extra output you're looking for. I like the flexibility of two pairs of tops though and I do love the 312As...

Al

[akillj]

I wasn't really thinking of going the DIY direction but thanks :P

Al, Thanks for the input. I was looking around for tops with greater output (Some of the ones you mentioned). But they're very expensive and will blow my budget.

[Evil Steve]

Akillj
There is a sound artifact called "comb filtering". The short story is that audio comb filtering is caused by placing two audio sources in close proximity to each other, and aiming them in the same direction.
If you plan on owning four 312a's, if you plan on using all four at the same time, and if you plan on pointing all four at the same area, then your audience will experience comb filtering.
The 312a is intended to run one speaker reproducing the left side of the stereo signal, and one speaker producing the right. If you try to go two and two, it won't improve your sound.

If what you have already does what you need it to do, and sounds good doing it, then you should leave well enough alone.
If your problem is that your speakers aren't loud enough for your event, then you must either buy a single set of speakers that can go louder, or multiple sets of speakers that are designed to be arrayed.
There's a reason why either of those types of speaker are more expensive to buy. They are more expensive to build. The fact that it goes beyond your budget is unfortunate.

There are methods you can use to minimize comb filtering, if you decide that you absolutely MUST buy the wrong equipment for your purpose.
If what you've got works, then just keep going with that.

As far as more bass goes, if you have enough bass for your purposes with two ls720's you should stick with them. They are excellent subs. If you feel you need more bass, then you might consider buying a third ls720. That depends on your purposes, again.
In my opinion, a single ls801 will outrun a pair of 312's. A pair of 720's seems like a good match for a pair of 312's. If you wanted a little more emphasis in the bass department, I'd suggest using some of the tricks listed around this site, like corner loading your bass, and clustering the bass cabinets together. I'd even suggest going with three ls720's clustered in front of you booth, and the 312's on stands to either side, before I suggested going with a pair of 801's.

The whole solution for you will depend on what you want to do. You will want to factor in stuff like transport, and storage, as well as cost.
For reasons mentioned all over this site, it would be a very bad idea to try to run a single ls801 with a pair of ls720's.
There may be solutions out there but I think they might require more discussion.
You are finalizing your plans, and I don't want to rain on your parade, but if you're looking for informed opinions from others on this site, I think those others might need a little more information.
Cheers
Evil

[windspeed36]

http://forums.prosoundweb.com/index.php/topic,137295.0.html worth a look

[Al Poulin]

Akillj
There is a sound artifact called "comb filtering". The short story is that audio comb filtering is caused by placing two audio sources in close proximity to each other, and aiming them in the same direction.
If you plan on owning four 312a's, if you plan on using all four at the same time, and if you plan on pointing all four at the same area, then your audience will experience comb filtering.
The 312a is intended to run one speaker reproducing the left side of the stereo signal, and one speaker producing the right. If you try to go two and two, it won't improve your sound.

If what you have already does what you need it to do, and sounds good doing it, then you should leave well enough alone.
If your problem is that your speakers aren't loud enough for your event, then you must either buy a single set of speakers that can go louder, or multiple sets of speakers that are designed to be arrayed.
There's a reason why either of those types of speaker are more expensive to buy. They are more expensive to build. The fact that it goes beyond your budget is unfortunate.

There are methods you can use to minimize comb filtering, if you decide that you absolutely MUST buy the wrong equipment for your purpose.
If what you've got works, then just keep going with that.

As far as more bass goes, if you have enough bass for your purposes with two ls720's you should stick with them. They are excellent subs. If you feel you need more bass, then you might consider buying a third ls720. That depends on your purposes, again.
In my opinion, a single ls801 will outrun a pair of 312's. A pair of 720's seems like a good match for a pair of 312's. If you wanted a little more emphasis in the bass department, I'd suggest using some of the tricks listed around this site, like corner loading your bass, and clustering the bass cabinets together. I'd even suggest going with three ls720's clustered in front of you booth, and the 312's on stands to either side, before I suggested going with a pair of 801's.

The whole solution for you will depend on what you want to do. You will want to factor in stuff like transport, and storage, as well as cost.
For reasons mentioned all over this site, it would be a very bad idea to try to run a single ls801 with a pair of ls720's.
There may be solutions out there but I think they might require more discussion.
You are finalizing your plans, and I don't want to rain on your parade, but if you're looking for informed opinions from others on this site, I think those others might need a little more information.
Cheers
Evil

I like the idea of adding 720Ps, but adding a single one isn't going to help much. He would have to add a pair to make a noticeable difference - for a total of 4 720Ps. The output of four 720Ps won't be quite as much as a pair of 801Ps, but not too far off and MUCH easier to move and handle IMO.

As for comb filtering, I believe the extra tops and subs are for teen dance type events. Comb filtering is barely noticeable to the average person and will be even less so for a bunch of teenagers who just want to party. The low price of the 312As and the fact that the OP already has a pair might simply make them the better value. Having multiple similar tops and subs makes your system very flexible. If would be better if the tops had a tighter dispersion pattern making them better to array, but I really don't think it's a big deal most of the time.

Al

[Subzeero]

As wonderful a speaker as the RCF 312a is, the 90x60 degree horn flare does not lend itself for use in horizontal arrays that are side by side.

Comb filtering in side by side applications can be minimized by using speakers that have narrower horn projection patterns.

You really need to consider speakers with 65-75 degree horizontal dispersion patterns with waveguide or modified waveguide horn flares.

They will still require splaying, in order to minimize the effects.

I know that the JBL PRX612ms are suitable and I am sure that there are others.

[Incognito]

Considering the OP is looking at covering school gym gigs he can easily use four RCF 312a tops with a pair as FOH & the 2nd pair as remote delay tops. The plus to this is rather then just getting more powerful FOH speakers is that he can have even coverage over the entire venue without having to blast a single pair to be able to get SPL coverage to the rear, the down side is that it may require the addition of a processor to add the required delay such as a decent DSP (if the OP doesn't already have one & if he doesn't a decent DSP can be picked up on the cheap in today's market starting around $200). If the OP doesn't want to have to run extra cables all over the place he would still have the option of going wireless & there are factory systems already preconfigured to cover such applications to take the guess work out of the whole process (however again this will be an extra cost but these systems can be picked up starting around $300). Either way four distributed tops will offer great coverage for his intended applications & will give the OP greater flexibility in set up options & system configurations but will take up a little more room in transport, take about an extra 15 minutes to set up & require additional processing (if OP doesn't already have said processing).

[Al Poulin]

As wonderful a speaker as the RCF 312a is, the 90x60 degree horn flare does not lend itself for use in horizontal arrays that are side by side.

Comb filtering in side by side applications can be minimized by using speakers that have narrower horn projection patterns.

You really need to consider speakers with 65-75 degree horizontal dispersion patterns with waveguide or modified waveguide horn flares.



Pretty much what I was saying in my post just above, but the comb filtering thing really isn't the end of the world or all that noticeable - especially for a teen dance in a gym, where the acoustics are pretty much shit to start with and where kids could care less or have any knowledge of what comb filtering is. For smaller bookings, the OP will probably be using just one pair of the 312As.

Al

[Evil Steve]

As for comb filtering, I believe the extra tops and subs are for teen dance type events. Comb filtering is barely noticeable to the average person and will be even less so for a bunch of teenagers who just want to party. The low price of the 312As and the fact that the OP already has a pair might simply make them the better value. Having multiple similar tops and subs makes your system very flexible. If would be better if the tops had a tighter dispersion pattern making them better to array, but I really don't think it's a big deal most of the time.

Al

Al. To an extent I agree with you.
The fact that a school gym is a terrible acoustic environment to try to provide sound in, I couldn't agree more.
That comb filtering is barely noticeable to the average person, I would disagree to some extent. I think the average person notices it, but is too ignorant to care that they hear it, or too ignorant to realize that it's being caused by a fool providing/running the PA system. Let me just remind anyone reading, that ignorant doesn't mean stupid. It means they just don't know.
Causing problems right from the start of your PA system, by intentionally introducing comb filtering, is not going to help matters, or make matters better, when dealing with a crappy acoustic environment. On the other hand, it will probably only make matters marginally worse, so I agree there is money to be saved by buying the wrong gear (not the truly "right" gear) for the purpose. A person could definitely pay lots more money for a really slick PA system, and it could still sound crappy in a school gym. If the flexibility of being able to make the system "modular" is desirable for the OP, then the four 312a/ four ls720p solution might be a good one. The OP just has to make the decision with as many facts as possible.

Incognito. To an extent I agree with you.
Running a distributed PA can be a great idea. There are many applications where a distributed PA is the perfect solution, for all the reasons you mentioned. I think a second pair of those 312's would be excellent candidates for a distributed system. Some processing gear would be necessary to make the system work, but again, it would add some expense. The worry I always have, especially when a group of people are involved, is how to protect my gear from those people, and how to protect those people from my gear. Running cables (power and audio) any distance can introduce a hazard. The use of wireless technology definitely reduces those hazards. Nevertheless, The stands the speakers sit on and the speakers themselves are a hazard. All hazards must be eliminated or controlled before people are exposed to them. Most people are ignorant of the hazards. I agree a distributed system can be an excellent solution, but the cost of eliminating or controlling the hazards introduced might make other solutions more suitable. If you have any links to the wireless distribution systems you mentioned, could you share? I've been interested in going distributed, but the wiring has always been a deal breaker for me, and going wireless always seemed to be too much of a gamble. If there's something out there that's dependable and inexpensive, I want to get a look at it.

In the end, it's up to the guy spending the money. All we can do is provide our best advice. I gotta say, there's a lot of good discussion coming from this topic.
Cheers
Evil

[DYM]

I would say go for it.. I have a pair of 312As and a LS801PB. The sub is definitely huge and my partners and I wouldn't be able to manage more than one, but it is loud and boomy - what you want for these events.

Would it be terrible if he got 2 more 50' XLR cables and daisy chained the speakers together? 2 Left, 2 Right? Crossover and your done? Just have them a fair distance away from each other and at a different distribution angle?

[Incognito]

Would it be terrible if he got 2 more 50' XLR cables and daisy chained the speakers together? 2 Left, 2 Right? Crossover and your done? Just have them a fair distance away from each other and at a different distribution angle?

Not a terrible idea, he could have them evenly spanned out over the length of the gym playing towards the other wall but this will induce a bit of an issue with the sound rebounding off of the opposing wall thus not do much to improve the already compromised acoustics of the gym.

[DYM]

Not a terrible idea, he could have them evenly spanned out over the length of the gym playing towards the other wall but this will induce a bit of an issue with the sound rebounding off of the opposing wall thus not do much to improve the already compromised acoustics of the gym.

Ok that sounds like the easiest approach to me... have your two inner speakers angled towards the center of the gym to the main "dance area" and have your two outer speaker angled slightly off center facing outwards for the expanded coverage.

[akillj]

Ok that sounds like the easiest approach to me... have your two inner speakers angled towards the center of the gym to the main "dance area" and have your two outer speaker angled slightly off center facing outwards for the expanded coverage.


Great knowledge in this thread guys. Thank you to all who contributed so far. But to dumb it down, Al was right, i'm basically trying to expand coverage, more then volume. I know what comb filtering is, but I've never experienced it so I don't have much input on that. I was basically thinking of doing what DYM was saying above, two closest speakers angled in a little ( for dance floor ) and the other two aimed forward or outward to cover the rest of the gym using my 50 foot xlr's daisy chained to my closer tops. Would this be acceptable?

Also, a crossover was mentioned, is it necessary to have a crossover?

I usually run my input through my subs and out to my tops. ( For a while I falsely thought my 720P's had a high pass output until someone here told me otherwise ). So I never had my tops high-passed.

[windspeed36]

Great knowledge in this thread guys. Thank you to all who contributed so far. But to dumb it down, Al was right, i'm basically trying to expand coverage, more then volume. I know what comb filtering is, but I've never experienced it so I don't have much input on that. I was basically thinking of doing what DYM was saying above, two closest speakers angled in a little ( for dance floor ) and the other two aimed forward or outward to cover the rest of the gym using my 50 foot xlr's daisy chained to my closer tops. Would this be acceptable?

Also, a crossover was mentioned, is it necessary to have a crossover?

I usually run my input through my subs and out to my tops. ( For a while I falsely thought my 720P's had a high pass output until someone here told me otherwise ). So I never had my tops high-passed.
They would get louder if you used a crossover because you have cut off the bass from your tops so therefore it does not need to produce a full range signal

[DYM]

I use 2 312A's and a LS801PB through a crossover... the bass is perfect and the tops are loud because they are only playing anything above 120 hz... a crossover makes a dramatic difference in sound output. I would pick one up before you ever go for the system upgrade here... you will need it anyways. See if with just the crossover it makes the difference you are looking for, maybe you do want another complete system running but check out that crossover, glad I could help :tup: (DBX 234)

[Incognito]

I use 2 312A's and a LS801PB through a crossover... the bass is perfect and the tops are loud because they are only playing anything above 120 hz... a crossover makes a dramatic difference in sound output. I would pick one up before you ever go for the system upgrade here... you will need it anyways. See if with just the crossover it makes the difference you are looking for, maybe you do want another complete system running but check out that crossover, glad I could help :tup: (DBX 234)

For the average price of a DBX 234 crossover you can get a full featured DSP witch would give the OP a much more power processor.

[DYM]

True.. I got mine for free with this great bundle deal.. Incognito, if you ca post a DSP I think it would help :tup:

[Subzeero]

Pretty much what I was saying in my post just above, but the comb filtering thing really isn't the end of the world or all that noticeable - especially for a teen dance in a gym, where the acoustics are pretty much shit to start with and where kids could care less or have any knowledge of what comb filtering is. For smaller bookings, the OP will probably be using just one pair of the 312As.

Al

Yes you did Al.

I was typing when you posted at 8:49 and I was interupted by a phone call and posted at 8:57.

By the time I posted mine you had already posted.

I posted and bolted out the door because I was going to be late for Breakfast and Golf with a 10:00 Tee Off.

I did not get to read your response until hours later and figured I was not going to be able to change it.

We both made mention of how to minimize the pattern whether it is required or not.

You really post some nice reviews about equipment.....just count me as a fan.

Are you a full time DJ or are you a Journalist who dables in DJing?

[jayhwk]

As for comb filtering, I believe the extra tops and subs are for teen dance type events. Comb filtering is barely noticeable to the average person and will be even less so for a bunch of teenagers who just want to party. The low price of the 312As and the fact that the OP already has a pair might simply make them the better value. Having multiple similar tops and subs makes your system very flexible. If would be better if the tops had a tighter dispersion pattern making them better to array, but I really don't think it's a big deal most of the time.


Al, I really don't agree - comb filtering is a problem that can seriously affect vocal intelligibility, among other things, when designing a sound system. It's frequency dependent, too, so you will still be able to hear some sound come out of the speakers, but there can be a lot of places where say 1000 Hz is 6 or 8 dB down due to the cancellations. That might not be super noticeable as comb filtering, but it will sound bad. You won't hear the comb filtering if you're expecting a broadband reduction in sound. I'm not sure if RCF puts out data for computer modeling programs, but if they do and I have a free minute, I might be able to come up with a few pictures for you.

You'll never be able to make comb filtering go away when you're arraying speakers, but there are things you can do to minimize it. There aren't many 12" boxes that are have 60 degree horns because 60 degree horns are larger than 90 degree, but using more directional speakers helps a lot. Using a single louder speaker is also a good option.

The bad acoustic environment will only become worse with improperly deployed loudspeakers - I wouldn't trust it to cover up major problems.

[Incognito]

True.. I got mine for free with this great bundle deal.. Incognito, if you ca post a DSP I think it would help :tup:

http://www.ebay.com/itm/BBE-DS-24-DIGITAL-CROSSOVER-/150796078674?pt=LH_DefaultDomain_0&hash=item231c258e52#ht_500wt_1413

[Incognito]

Al, I really don't agree - comb filtering is a problem that can seriously affect vocal intelligibility, among other things, when designing a sound system. It's frequency dependent, too, so you will still be able to hear some sound come out of the speakers, but there can be a lot of places where say 1000 Hz is 6 or 8 dB down due to the cancellations. That might not be super noticeable as comb filtering, but it will sound bad. You won't hear the comb filtering if you're expecting a broadband reduction in sound. I'm not sure if RCF puts out data for computer modeling programs, but if they do and I have a free minute, I might be able to come up with a few pictures for you.

You'll never be able to make comb filtering go away when you're arraying speakers, but there are things you can do to minimize it. There aren't many 12" boxes that are have 60 degree horns because 60 degree horns are larger than 90 degree, but using more directional speakers helps a lot. Using a single louder speaker is also a good option.

The bad acoustic environment will only become worse with improperly deployed loudspeakers - I wouldn't trust it to cover up major problems.

:tup: I agree, if you can do something about it then you should. It's our job to provide the best service possible & this includes proper audio, we shouldn't be purposely introducing potential issues t an already bad issue to start with.

[audiopyle]

I haven't tried it with the 312As, but I have arrayed 2 ART325i cabs per side on occasion with good results. Some experimenting with cabinet splay angle has delivered very acceptable sound with minimal audible combing, and no problem with speech intelligibilty. In the end the cabinets were splayed much less than one would expect for a 90 degree horn.

[akillj]

After reading the replies, it seems like you guys highly recommend me getting a crossover, would a bbe ds24 be a good one to use as a crossover ?

[Subzeero]

Al, I really don't agree - comb filtering is a problem that can seriously affect vocal intelligibility, among other things, when designing a sound system. It's frequency dependent, too, so you will still be able to hear some sound come out of the speakers, but there can be a lot of places where say 1000 Hz is 6 or 8 dB down due to the cancellations. That might not be super noticeable as comb filtering, but it will sound bad. You won't hear the comb filtering if you're expecting a broadband reduction in sound. I'm not sure if RCF puts out data for computer modeling programs, but if they do and I have a free minute, I might be able to come up with a few pictures for you.

You'll never be able to make comb filtering go away when you're arraying speakers, but there are things you can do to minimize it. There aren't many 12" boxes that are have 60 degree horns because 60 degree horns are larger than 90 degree, but using more directional speakers helps a lot. Using a single louder speaker is also a good option.

The bad acoustic environment will only become worse with improperly deployed loudspeakers - I wouldn't trust it to cover up major problems.

It certainly seems that there are not many powered 12" speakers much below 90 degrees wide. The old EV SXA360 was a 65 x 65 CD horn flare.
On the passive side of things there are many more options. I have EV SX300s that are 65 x 65. The EV ZX3-60s are 60 x 60, and the JBL MRX512ms have a modified waveguide horn flare that is 70 x 70.

I have to agree with Incognito that it is a sound provider's responsibility to provide equipment suitable for the job. To do anything less borders on being a little unprofessional. In a pinch, I can see someone having to make the best of what is available under the circumstances, but i would not make a habit of it.

[Incognito]

After reading the replies, it seems like you guys highly recommend me getting a crossover, would a bbe ds24 be a good one to use as a crossover ?

The BBE DS24 is a DSP, it has a built in crossover as well as a few other goodies built into a single rack space that gives you more control over your over all system then what a crossover alone could.

[jayhwk]

It certainly seems that there are not many powered 12" speakers much below 90 degrees wide. The old EV SXA360 was a 65 x 65 CD horn flare.
On the passive side of things there are many more options. I have EV SX300s that are 65 x 65. The EV ZX3-60s are 60 x 60, and the JBL MRX512ms have a modified waveguide horn flare that is 70 x 70.


The problem is that the horn is just too small. Even though the ZX-3 is listed as a 60x60 horn, it's only holds its directivity down to 1.5kHz, whereas the 60x60 Zx5 with a bigger horn holds its pattern to 1kHz and looks much better even below that. At least EV gives good data for most loudspeakers - many manufacturers no longer provide directivity data - so that "60 degree nominal" is basically meaningless.

I have three Electro-Voice 60x40 stadium horns sitting around that will hold their pattern in both directions down to 500 Hz (plus, you can get like 133 dB at one meter with a DH1A driver and 100W power amplifier). I wish I could use them - they're just too big!

[Subzeero]

The problem is that the horn is just too small. Even though the ZX-3 is listed as a 60x60 horn, it's only holds its directivity down to 1.5kHz, whereas the 60x60 Zx5 with a bigger horn holds its pattern to 1kHz and looks much better even below that. At least EV gives good data for most loudspeakers - many manufacturers no longer provide directivity data - so that "60 degree nominal" is basically meaningless.

I have three Electro-Voice 60x40 stadium horns sitting around that will hold their pattern in both directions down to 500 Hz (plus, you can get like 133 dB at one meter with a DH1A driver and 100W power amplifier). I wish I could use them - they're just too big!

Are we talking medium format HP640s or large format HP6040s?

Those are a long time ago for me.:)

They have probably been replaced by more modern versions, of which I have no knowledge.

[Incognito]

True.. I got mine for free with this great bundle deal.. Incognito, if you ca post a DSP I think it would help :tup:

Here's another DSP option for the same going price as what the DBX 234 crossover goes for & the best part is it's designed for powered speakers. http://www.ebay.com/itm/DBX-DRIVERACK-PX-POWERED-SPEAKER-OPTIMIZER-W-MIC-/180861326653?_trksid=p3286.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D3%26po%3D LVI%26ps%3D63%26clkid%3D7782106343180371514#ht_822 wt_1396

[jayhwk]

Are we talking medium format HP640s or large format HP6040s?

Those are a long time ago for me.:)

They have probably been replaced by more modern versions, of which I have no knowledge.

HP6040s! The day the UPS freight truck showed up was the day I learned the difference between a 6040 and a 640... A friend wanted the DH1As and I wanted the low frequency speakers that came with the lot. I thought the horns were HP640s, and I was quite surprised when each horn was on its own pallet.

I think they were the end of the line for EV's big stadium horns... nowadays everything has to be in a box, even if it doesn't work as well as separate components. I think they might still produced for cinema, though.

[Subzeero]

HP6040s! The day the UPS freight truck showed up was the day I learned the difference between a 6040 and a 640... A friend wanted the DH1As and I wanted the low frequency speakers that came with the lot. I thought the horns were HP640s, and I was quite surprised when each horn was on its own pallet.

I think they were the end of the line for EV's big stadium horns... nowadays everything has to be in a box, even if it doesn't work as well as separate components. I think they might still produced for cinema, though.


9.5 lbs vs 20 lbs!


Thank God that they were not the not the 155 lb MH6040s used with the DL 10X-SH woofers!!!

:D