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Author Topic: factors to consider when replacing FOH speakers  (Read 1773 times)

Matt Greiner

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factors to consider when replacing FOH speakers
« on: August 06, 2018, 11:18:32 pm »

I saw an older thread on this subject, and decided to start a new thread instead of waking a zombie.  I'm trying to compare some newer speakers to what I currently have.  I'm not in an area where I can demo the gear, so before I make a 3-4 hr trip to demo, I'd like to try and narrow down my choices.

Here's what I currently use, and what I'm considering replacing them with.

Main reasons I am considering the switch -
Weight and age (feels like a shallow dating site now....  lol)  Cost is not a major factor in my decision.

I use 4 of the Peavey QW2F's for my mains for my larger shows, sometimes I run them full range, sometimes I biamp them.  The QW2F's come in right around 100 pounds each.  When I run them full range, add another 50 pounds per pair for an amp (another 35 for the HF amp).  I like their sound, and I don't push them near clipping, I've always had plenty of headroom with them.

Take the RCF ART 745-A MK4.  It's a powered speaker, coming in at a little over 41 pounds.  It has a 90x60 horn (the QW2 has a 90x40). Both use a 4" compression driver, and have similar peak SPL (Peavey 132, RCF 133).

Now I know that wattage is a bad measuring stick from reading these forums, but it seems a little crazy to me that there is such a difference in the ratings, when the specs are so similar.  The QW2F (full range) is rated at 800/1600/3200 watts continuous/program/peak, and the built in RCF amp (full range) is rated at 700/1400 watts RMS/peak.

I've always had the opinion that passive is better than powered, mainly because I like the flexibility of having spare gear around that can work with more than a single piece of gear.  Amp goes out, I can patch another in and get through the show.  Speaker goes, I carry replacement woofers and diaphragms with me.

Some people have recommended the QSC K12.2, but I don't think they'll be able to keep up.

Are there any other factors that I should be considering when comparing the 2?  Or any other options I should consider looking at?

Matt
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Caleb Dueck

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Re: factors to consider when replacing FOH speakers
« Reply #1 on: August 07, 2018, 12:05:25 am »

If you like passive and want some SPL, here are a few more options-
Danley SM80
JTR 3TX
Fulcrum DX1295(FP)
TW Audio T24N
Martin CDD 15
RCF TT5A (not passive)


Sent from my VS980 4G using Tapatalk

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Rick Powell

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Re: factors to consider when replacing FOH speakers
« Reply #2 on: August 07, 2018, 12:43:24 am »

Now I know that wattage is a bad measuring stick from reading these forums, but it seems a little crazy to me that there is such a difference in the ratings, when the specs are so similar.  The QW2F (full range) is rated at 800/1600/3200 watts continuous/program/peak, and the built in RCF amp (full range) is rated at 700/1400 watts RMS/peak.

Matt

A speaker that produces 98dBa/1 watt/1 meter will need a lot more wattage than a speaker that produces 108dBa/1 watt/1 meter at the same measured frequency range, to achieve the same volume under identical conditions. It's about efficiency as much as it is about watts.

Caleb's list above is a good bunch of candidates that are relatively efficient, can take a decent amount of power, and sound relatively good near the top end of their rated output (which some speakers never reach their theoretical output under real world conditions, others only meet it within a certain narrow frequency range, and others might "hit a number" but sound like dog doo-doo doing it).
« Last Edit: August 07, 2018, 12:52:23 am by Rick Powell »
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Chris Grimshaw

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Re: factors to consider when replacing FOH speakers
« Reply #3 on: August 07, 2018, 03:20:49 am »


Now I know that wattage is a bad measuring stick from reading these forums, but it seems a little crazy to me that there is such a difference in the ratings, when the specs are so similar.  The QW2F (full range) is rated at 800/1600/3200 watts continuous/program/peak, and the built in RCF amp (full range) is rated at 700/1400 watts RMS/peak.

Remember that the "peak" ratings on passive speakers are extremely short duration signals, and still on the edge of survivability.

The RCF ART boxes seem quite well-liked, although I haven't seen much about the Peavey cabs you've mentioned. Looks to me like they're both mid-power 15" two-way cabinets. The RCFs might sound a bit nicer as they'll have dedicated processing.

If you wanted to stay with 15" two-way speakers, a good compression driver is a must to make that format sound good - 15" cones don't do too well past 1kHz, so you need something reasonably hefty to take over from there.

FWIW, I used to work with SSE Betamax which weighed the same as your Peavey cabinets (43kg). If you've been getting those on to stands by yourself, I'm impressed.

Chris
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Alec Spence

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Re: factors to consider when replacing FOH speakers
« Reply #4 on: August 07, 2018, 08:40:32 am »

Now I know that wattage is a bad measuring stick from reading these forums, but it seems a little crazy to me that there is such a difference in the ratings, when the specs are so similar.  The QW2F (full range) is rated at 800/1600/3200 watts continuous/program/peak, and the built in RCF amp (full range) is rated at 700/1400 watts RMS/peak.
And you realise why comparing wattage is a bad measuring stick?  By itself it will tell you nothing about how loud a box will go, nor how gracefully it will get you there.  Comparing SPL levels gives you much more of an idea, but still won't tell you the whole story.

I've always had the opinion that passive is better than powered, mainly because I like the flexibility of having spare gear around that can work with more than a single piece of gear.  Amp goes out, I can patch another in and get through the show.  Speaker goes, I carry replacement woofers and diaphragms with me.
With the protection built into decent active speakers, you're much less likely to blow drivers.  And with a decent collection of matching/similar active cabs, you can always repurpose.

My small mobile rig is 2 x RCF ART 722 over ART 705, with 4 x ART 722 for monitors.  If I lose one of my FOH speakers, I'd run mono or steal a monitor, which would get me through a gig.  That said, after 10 years with this kit, it continues to work without a hitch.

Granted, passive makes cabling round the stage a little easier, but there's an extra amp rack to transport.  In the end, neither approach is "better" than the other.  And it's more than a bit daft to say that one sounds better than the other.
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Peter Morris

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Re: factors to consider when replacing FOH speakers
« Reply #5 on: August 07, 2018, 09:49:08 am »

I saw an older thread on this subject, and decided to start a new thread instead of waking a zombie.  I'm trying to compare some newer speakers to what I currently have.  I'm not in an area where I can demo the gear, so before I make a 3-4 hr trip to demo, I'd like to try and narrow down my choices.

Here's what I currently use, and what I'm considering replacing them with.

Main reasons I am considering the switch -
Weight and age (feels like a shallow dating site now....  lol)  Cost is not a major factor in my decision.

I use 4 of the Peavey QW2F's for my mains for my larger shows, sometimes I run them full range, sometimes I biamp them.  The QW2F's come in right around 100 pounds each.  When I run them full range, add another 50 pounds per pair for an amp (another 35 for the HF amp).  I like their sound, and I don't push them near clipping, I've always had plenty of headroom with them.

Take the RCF ART 745-A MK4.  It's a powered speaker, coming in at a little over 41 pounds.  It has a 90x60 horn (the QW2 has a 90x40). Both use a 4" compression driver, and have similar peak SPL (Peavey 132, RCF 133).

Now I know that wattage is a bad measuring stick from reading these forums, but it seems a little crazy to me that there is such a difference in the ratings, when the specs are so similar.  The QW2F (full range) is rated at 800/1600/3200 watts continuous/program/peak, and the built in RCF amp (full range) is rated at 700/1400 watts RMS/peak.

I've always had the opinion that passive is better than powered, mainly because I like the flexibility of having spare gear around that can work with more than a single piece of gear.  Amp goes out, I can patch another in and get through the show.  Speaker goes, I carry replacement woofers and diaphragms with me.

Some people have recommended the QSC K12.2, but I don't think they'll be able to keep up.

Are there any other factors that I should be considering when comparing the 2?  Or any other options I should consider looking at?

Matt

The  Peavey QW2F's you have are quite serious speakers. 

I would look at the RCF ART 745-A MK4 you mentioned or even better the RCF TT25a MK2.  Its never really a good idea to put 2 of these or your QW2F side by side to make it louder because of the comb filtering that happens. I think a better option would be to add an 18 inch sub such as the RCF SUB 8004-AS or maybe the  SUB 8003-AS II when you need more power.

The advantage of these speakers over the passive system is that they always operate bi-amped using advanced signal processing, especially the latest series from RCF with FIR Phase.

The QSC K12.2 is a very nice sounding speaker, but I don't think it will deliver the SPL you want.

Some of the speakers that Caleb mentioned are great, but many of them need to be used with a sub (SM80, 3TX & T24).

The SM80 + TH118 sub  or  3TX + CAPTIVATOR 118PRO / 218 sub would be a great solution, but you will always need to use a sub.
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Matt Greiner

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Re: factors to consider when replacing FOH speakers
« Reply #6 on: August 07, 2018, 03:13:31 pm »

A speaker that produces 98dBa/1 watt/1 meter will need a lot more wattage than a speaker that produces 108dBa/1 watt/1 meter at the same measured frequency range, to achieve the same volume under identical conditions. It's about efficiency as much as it is about watts.

Looking at my spec sheet, my QW2F's are listed as 97 dB SPL (2.83 V input) 1 watt/1 meter.  I looked and I couldn't find a similar spec for the 745's.  Perhaps someone knows it, or if I just overlooked it.  I looked on the spec sheet and manual, and all I could find was the peak number.  Or will it not exist since it's a powered speaker?
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Matt Greiner

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Re: factors to consider when replacing FOH speakers
« Reply #7 on: August 07, 2018, 03:16:05 pm »

Remember that the "peak" ratings on passive speakers are extremely short duration signals, and still on the edge of survivability.

Agreed.  I normally use the program rating for all of my calculations and when I match up amplifiers for my subs/lows/mids.  I use the peak rating for my highs though.
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Matt Greiner

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Re: factors to consider when replacing FOH speakers
« Reply #8 on: August 07, 2018, 03:34:26 pm »

The  Peavey QW2F's you have are quite serious speakers. 

I would look at the RCF ART 745-A MK4 you mentioned or even better the RCF TT25a MK2.  Its never really a good idea to put 2 of these or your QW2F side by side to make it louder because of the comb filtering that happens. I think a better option would be to add an 18 inch sub such as the RCF SUB 8004-AS or maybe the  SUB 8003-AS II when you need more power.

What I have been doing is putting 2 of the QW2's per side, stacked on top, and then invert the top cabinet so the horns can couple together and get a natural 3 dB boost.  I'll attach a photo.  I don't normally stack them like this, the single 18's usually stay in the shop.  I think I was trying out the system as a 4 way that day. (subs are under the trailer for this show)

I use VR218's for my subs, total of 4 boxes.  I could do a single QW118, then stack the QW2 on top of it.  The QW118 is a single 18, then I could raise my crossover frequency on the QW2's and let the 118 do some of the heavy lifting in the 100-250 Hz range.

So even if I switch to the ART 745's or something similar, I may still need a little extra help from a single 18.
« Last Edit: August 07, 2018, 03:40:23 pm by Matt Greiner »
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Matt Greiner

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Re: factors to consider when replacing FOH speakers
« Reply #9 on: August 07, 2018, 06:10:02 pm »

I don't know how much i am really gaining by running my tops this way.  If someone has an idea or a way for me to calculate that, it would be appreciated.  I mean, if I've been lugging them around for just 3 db extra headroom, not sure if thats worth it.
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Re: factors to consider when replacing FOH speakers
« Reply #9 on: August 07, 2018, 06:10:02 pm »


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