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QSC CP8 PA Speaker vs. 8" Studio Monitors

andreasmaaan

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I should have stated up front that over the years I've personally experienced both live and recorded music played through a variety of PA speakers in small venues. The best small venue pro sound I ever heard led me to walk up and ask the sound engineer what the tiny speakers were that were creating such a huge soundstage. He showed me that they were 8" active EV ZXA1-90 speakers and said they were his personal favorites. They had a clean, clear unstrained quality that I've never experienced with any of my home audio speakers.

That makes more sense now. You're set on buying PA speakers. I can understand that (I very much like, and used to design, PA speakers, and one thing I like about the 308P is that it has similar radiation to a classic PA speaker with a CD horn like the CP8, but also has the accuracy of a studio monitor, which is rare in budget PA gear).

I would be perfectly comfortable with EV ZXA1-90 speakers in my home. However, they cost $100 each more than the QSC CP8 and are an older design. Those who've compared the CP8 to the ZXA1-90 mostly agree that they are at least comparable in overall performance.

They are very similar. On the basis of the limited info we have, CP8 appears in fact to be a slightly better speaker :)

As for in room performance potentially extending the distance at which 85 dB continuously with 20 dB headroom can be achieved I had not previously seen this mentioned in any of my extensive reading so it doesn't seem to be a widely acknowledged feature.

It's not a "feature". It's just physics ;) Once you've passed the critical distance (the point at which the level of direct sound is equal to the level of reflections), the SPL doesn't really change much no matter how far from the speakers you go (except in corners, where bass will on average be louder).

What I have seen documented on other AV forums is measured real world performance that LP-8/308P class 8" active studio monitors fall short of achieving THX reference beyond 10 feet and sound strained and compressed trying to achieve it whereas active PA speakers in the same environments have achieved measured THX reference beyond 10 feet with no sign of strain or compression.

The max. SPL specs provided by companies like JBL or QSC (indeed, especially QSC, IME) are not necessarily accurate. My comments earlier are based on the assumption that JBL's specs are accurate, which may not be true.

Anyway, I'd be really interested in reading these AV forum links you mentioned. Would you mind sharing them?

So while I think I could be satisfied with something like the Kali or JBL 8" active studio monitors I believe the CP8 would come closer to capturing that special experience I had listening to the EV ZXA1-90 active PA speakers. My priority is effortlessly reaching THX reference at part throttle to use an automotive term. In either case I would be crossing at 80 Hz to a sub so bass performance is not an issue.

This goes to my previous question, actually. When you say people on AV forums have reported the 308P struggling to reach THX ref levels, was that with or without a + sub? (Again, I ask merely out of personal curiosity here.)
 

theyellowspecial

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If you're talking about the "direct sound dominance" chart, they have bookshelf sized monitors going up to 3m(S360A, 8361A), and main monitors going up to 5m(1236A).

Direct sound dominance is a studio monitoring preference for obvious reasons(you want to hear what you are putting on the track, not anything to do with your room), but that does not follow to it being a home listening preference. There it's really down to a matter of personal preference, room characteristics, etc.

There are very, very few speakers with narrow enough dispersion to be >3m on this chart. Most hi-fi floorstanders and bookshelves would not be.
Thank you. So their recommendations are just a matter of directivity. That clears up a lot and I can square it with the early reflections data in the speaker explorer and my experience with various speakers in my room.

I definitely forgot about the larger options on their chart. I think I just overlooked those due to the cost. I would definitely go for the more cost-effective Neumann KH120 if I went for an active monitor with narrow directivity.
 
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More Dynamics Please

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That makes more sense now. You're set on buying PA speakers. I can understand that (I very much like, and used to design, PA speakers, and one thing I like about the 308P is that it has similar radiation to a classic PA speaker with a CD horn like the CP8, but also has the accuracy of a studio monitor, which is rare in budget PA gear).

They are very similar. On the basis of the limited info we have, CP8 appears in fact to be a slightly better speaker :)

It's not a "feature". It's just physics ;) Once you've passed the critical distance (the point at which the level of direct sound is equal to the level of reflections), the SPL doesn't really change much no matter how far from the speakers you go (except in corners, where bass will on average be louder).

The max. SPL specs provided by companies like JBL or QSC (indeed, especially QSC, IME) are not necessarily accurate. My comments earlier are based on the assumption that JBL's specs are accurate, which may not be true.

Anyway, I'd be really interested in reading these AV forum links you mentioned. Would you mind sharing them?

This goes to my previous question, actually. When you say people on AV forums have reported the 308P struggling to reach THX ref levels, was that with or without a + sub? (Again, I ask merely out of personal curiosity here.)

Many thanks for your thoughtful and informative response. I do still waver back and forth a bit on the 8" active studio monitor vs. comparable PA speaker which is why I posted here to get the kind of educated feedback common to this forum. Finding the exact links I mentioned could be a challenge. I've been reading the speaker section at AVS Forum for more than 10 years and have a lot of accumulated memories. :)

There's a whole group of different people there who have experimented over the years with a variety of active studio monitors in their home theaters of varying sizes who ended up switching to PA speakers because they couldn't get clean reference levels to their satisfaction. In all cases they were using a sub or multiple subs with most crossing over at 80 Hz. These people taken together as a group probably have tens of thousands of posts on that forum.

Actually one of the more prolific posters in those AVS Forum discussions is also a member of this forum -- @Archaea . He tried Behringer Truth 2031A active monitors with 8.75" woofers that produce substantial SPL but which he found inadequate for reference levels in his home theater. He mentions this here on this forum at the following link which in turn has a link to his Behringer Truth experience on AVS Forum:

https://www.audiosciencereview.com/...tudio-monitor-review.17338/page-2#post-561657
 

turbotuff

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Many thanks for your thoughtful and informative response. I do still waver back and forth a bit on the 8" active studio monitor vs. comparable PA speaker which is why I posted here to get the kind of educated feedback common to this forum. Finding the exact links I mentioned could be a challenge. I've been reading the speaker section at AVS Forum for more than 10 years and have a lot of accumulated memories. :)

There's a whole group of different people there who have experimented over the years with a variety of active studio monitors in their home theaters of varying sizes who ended up switching to PA speakers because they couldn't get clean reference levels to their satisfaction. In all cases they were using a sub or multiple subs with most crossing over at 80 Hz. These people taken together as a group probably have tens of thousands of posts on that forum.

Actually one of the more prolific posters in those AVS Forum discussions is also a member of this forum -- @Archaea . He tried Behringer Truth 2031A active monitors with 8.75" woofers that produce substantial SPL but which he found inadequate for reference levels in his home theater. He mentions this here on this forum at the following link which in turn has a link to his Behringer Truth experience on AVS Forum:

https://www.audiosciencereview.com/...tudio-monitor-review.17338/page-2#post-561657
Look into used Mackie HR824
 

andreasmaaan

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Many thanks for your thoughtful and informative response. I do still waver back and forth a bit on the 8" active studio monitor vs. comparable PA speaker which is why I posted here to get the kind of educated feedback common to this forum. Finding the exact links I mentioned could be a challenge. I've been reading the speaker section at AVS Forum for more than 10 years and have a lot of accumulated memories. :)

There's a whole group of different people there who have experimented over the years with a variety of active studio monitors in their home theaters of varying sizes who ended up switching to PA speakers because they couldn't get clean reference levels to their satisfaction. In all cases they were using a sub or multiple subs with most crossing over at 80 Hz. These people taken together as a group probably have tens of thousands of posts on that forum.

Fair enough :)

Well, after reading what you wrote I tracked down Sound&Recording's measurements of the LSR 308 (predecessor of the 308P) because I wanted to see if it really was as SPL-limited as you recall reading on AVForum.

Turns out it falls short of published specs by quite a bit :

1605815189496.png


The QSC has around a 10dB advantage over it above 100Hz (as does the Mackie HR824 FWIW, although the QSC appears to me to be a better speaker overall, notwithstanding the Mackie's significantly greater bass extension - which is not going to matter much when used with subs anyway).

As to your broader question about whether to go with the QSC or an 8" studio monitor, I think the QSC looks like a good speaker, which could be made into a great speaker with a touch of EQ (if that's a possibility?). I'd think it a good value proposition in its class, whether compared to small PA speakers or larger studio monitors.

In terms of comparisons with other PA speakers, unfortunately few have detailed measurements published, so it's hard to say unequivocally that there's not a better alternative out there. But I do think it's possible to say that the CP8 is going to be among the better options (especially with EQ!).
 

turbotuff

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Also consider the JBL IRX108BT and IRX112BT if you want bluetooth steaming.
 
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More Dynamics Please

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It really helps to have someone who has designed PA speakers and who also appreciates active studio monitors confirm the results of my long research project that the QSC CP8 would probably make a good performing home speaker and even a great one with some EQ. I'm certainly willing to consider something like a miniDSP and UMIK-1 if I decide good isn't good enough. :)

I also appreciate the suggestions on the other speakers. No doubt the Mackie H824 is worth considering. But I've never been big on used equipment and have always preferred buying new. I also considered the new JBL IRX108BT even though I don't care about bluetooth streaming. One thing that bothered me is that JBL didn't list crossover frequency in any of their specs. I finally ended up contacting JBL tech support and they had to check with the designer to find out it had a 3kHz crossover. I thought that was a bit high to run an 8" driver and much prefer the 2.2kHz crossover of the QSC CP8.

I've really done a lot of research on the finer details of all potential active PA speakers selling for no more than $400 per unit. I focused in on 8" models as the sweet spot based on reading many different user experiences expressed on pro forums as well as my own experience hearing many different PA speakers in small venues and preferring the overall sound of the EV ZXA1-90, especially on vocals. Point by point, feature by feature the selection process slowly narrowed down to the CP8 coming out on top.
 

BDWoody

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Many thanks for your thoughtful and informative response. I do still waver back and forth a bit on the 8" active studio monitor vs. comparable PA speaker which is why I posted here to get the kind of educated feedback common to this forum.

I would also suggest that the JBL 708P, with 500wpc, has a whole different level of SPL capability than the lower level speakers. For room filling reference levels, you need more than most smaller speakers can deliver.

I can say at 14', I don't ever max these out, and I listen at a level most would consider loud.

Not all 8" monitors are created equal...
 
OP
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More Dynamics Please

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Among the dozens of speakers I considered, the KRK 10-3 G4 was among them. But KRK rates max SPL at only 112 dB. It seems they went for bass extension (26 Hz) over SPL, so for those who don't want to run a sub the 10" woofer gives it an advantage over 8" and smaller models. But the bass extension is wasted for those running a sub.

I will gladly jump on the JBL 708P the instant someone points me to a legitimate vendor offering them at my budget point of $400 each. :)
 

richard12511

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QSC generally makes excellent speakers IMO, usually very competitive in any given price/class.

However, I would just question one starting assumption you've made here, i.e. that a speaker like e.g. 308P will not produce 85dB continuous with 20dB of headroom at a distance of 12 feet or more in-room.

According to the 308P manual, it's rated at 102dB continuous / 112dB peak @1m.

I assume that you've calculated your SPL requirements based on the inverse square law, which would give you approx. 91dB continuous / 101dB peak @12 feet for the 308P. Is that correct?

If so, I think your failure to take into account the effects of reflections on SPL level mean that you are significantly underestimating the SPL your these speakers will actually produce at a listening distance of 12 feet.

I explained the reasons for this in some detail here.

THX reference levels are based on the SPL at the listening position in-room, not on the anechoic SPL capability of the speakers.

I think that you may be right that the 308p are capable of hitting reference level peaks in a real room, but I'd be concerned how good they would sound doing it. IME, most speakers start sounding "too loud" as you approach their limits. Some can handle it better, but the 308p was already starting to show heavy distortion at 96dB. Also, I generally like to have about 10dB headroom over the loudest levels I plan to listen out. This extra headroom helps to cover differing peaks in different content. 20dB peaks are the standard, but some movies might be +25, while others might be +15. Also, you're probably gonna lose a little headroom from EQing the speakers.

708p will definitely handle reference levels, though. I had the pleasure of hearing a 708/705p HT a few years ago, and it sounded fantastic! We pushed it to reference levels and even a little beyond, and it continued sounding great. Unfortunately, it's also much more expensive :(.
 
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