It puzzles me that they don't have any. How did they come up with the two figures they gave you? I assume the speaker went in an anechoic chamber for testing. Why shouldn't they share that graph with their customers? If the speaker is so flat as they claim they should share as many documents as possible to back their claims and show people how good their speakers are.
Posted by Mark Gulbrandsen (Member # 72) on 07-19-2015, 09:35 AM:
Not all manufacturers test in an anechoic chamber. We certainly don't listen in one. Some companies actually do testing out doors and in real life. Meyer Sound Labs is one that does that...
Mark
Posted by Steve Guttag (Member # 268) on 07-19-2015, 09:57 AM:
A VERY bad trend in speaker manufacturers that have their own DSP brand associated with them (like Harmon does with dbx and BSS ) is that they will come up with their own special DSP settings that may have been done in an anechoic chamber and may have even been done with their own super-duper testing that they think gives validity. As such, the specs are based on that and so long as you use their DSP, it should all work.
Mark brings up a valid point...anechoic chamber testing is but one sort of test to see how the components perform without outside influences...but how do they perform in their intended application? There are speakers that don't "look" so bad on their anechoic response but absolutely sound horrendous, particularly in theatrical environments.
I've found that factory settings don't always work the best in the world...I've really seen this on time delays for time alignment on multi-way systems. And if you aren't using the system that the speaker manufacturer tested it on, it definitely will be different due to the differing processing times.
I expect speaker manufacturers to provide frequency response curves and ideally polar plots on the horn loaded stuff but they rarely do. These give good indication as to what one can expect.
With the smaller "Economical" systems, one is less likely to get detailed information. It probably doesn't help their cause to publish them since it is less likely a value priced system is going to perform like a higher-end system. There is no "free" in this world. Using a -10dB response may be standard for the industry but it really doesn't tell you when it started to nose dive nor what sort of bouncy response it has in the pass-band.
Another thing to look out for in speaker specs is the sensitivity. The standard is 1-watt/1-meter. When one uses the voltage like 2.83V...they are likely hiding something because they want YOU to do the math (and it isn't hard...V^2/R = Watts)...Miss reading this spec will likely make you think it is more sensitive (needs less power) than it does.
Posted by Marco Giustini (Member # 4544) on 07-19-2015, 02:36 PM:
I firmly believe a speaker should be tested and that we should have the data.
Ok, the anechoic chamber may not be a real world test but I feel a professional manufacturer should test their speakers in the anechoic chamber and provide the data to their customers. After all, the anechoic chamber gives you some invaluable data and I don't see how a professionally designed speaker could be as such without that test.
Anyway, QSC said that the speaker is +/-2dB till 19K in an anechoic chamber. So, according to QSC, that speaker was tested in there. Then the datasheet says 19K -10dB. It seems that one of the statements is wrong here.
I am very sceptical of manufacturers that don't put attention on the datasheets. I choose my speakers based on them. A mistake on the datasheet is like a grammar mistake on a CV, it immediately spoils the general idea of the candidate.
Posted by Mark Gulbrandsen (Member # 72) on 07-19-2015, 05:47 PM:
Marco,
You should call John Meyer and talk with him. He gave a talk at one of the Dolby Training classes I went to back in the early 1980's that lasted over three hours. He was talking so far over everyone's head (physics) that it was almost unbelievable. He did talk at length about testing speakers outdoors vs. in a chamber and I know at that time he completely abandoned chambers. I think his products also speak for themselves... at least for those that can afford them.
Mark
Posted by Marco Giustini (Member # 4544) on 07-20-2015, 03:33 AM:
What I am saying is that I am expecting some kind of test results from a manufacturer and not just a listening test or inconsistent data.
I am happy to discuss the anechoic chamber topic but I am not ready to accept a datasheet that says "it just sounds great".
That is ok in the Hi-Fi world.
Posted by Gerald Dente (Member # 8927) on 07-20-2015, 11:32 AM:
We can assume they measured the speaker when they built it and that data should exist some place right? Or do people just throw together parts in a box, package it up and sell it without any testing? No, I think not.
All I would like is some of the data they had when testing out the speaker. Help me determine GENERALLY how it will sound and how it will be off axis. That's not asking for to much and a company like QSC I would expect a bit more in that regard.
Posted by Marco Giustini (Member # 4544) on 07-20-2015, 12:12 PM:
I second that.
Posted by Avi Bm (Member # 8776) on 07-20-2015, 02:23 PM:
I have the 3 qsc sc 1120 in a 2500 cubic ft room.
The are incredible. Vocals dynamic flat accurate. I also have 2 SB 1180 but it does seem an over kill. At least in my room. At the moment 1 sub sounds better than two. The qsc were good with or without a baffle wall.
2 jbl 8320 at the back adding more channels.
Wonder whether anyone can recommend qsc atmos ceiling spkrs(mounted) for a small room.
Posted by Gerald Dente (Member # 8927) on 07-20-2015, 03:07 PM:
You by chance havent taken any measurements of your speakers have you?
Posted by PoiNguan Goh (Member # 9184) on 11-27-2015, 07:26 PM:
@ Avi Bm
DO you have any measurement for the QSC SC 1120?
Anyone else in here have the 1150?
Posted by System Notices (Member # 2357) on 08-02-2017, 04:03 AM:
It has been 613 days since the last post.
Posted by Hans Van Meenen (Member # 10131) on 08-02-2017, 04:03 AM:
I ordered the QSC sc-1150 today. Hope I won't regret replacing my old but relative high end speakers. I just needed more dynamics and integration.
Anybody else who has them?
I will keep this post updated with my experience
Posted by Mark Gulbrandsen (Member # 72) on 08-02-2017, 02:25 PM:
I've installed lots of them in small cinemas. They are excellent sounding.
Mark
Posted by Jarod Reddig (Member # 6363) on 08-03-2017, 12:14 AM:
Congrats Hans! Looking forward to your opinion.
Posted by Hans Van Meenen (Member # 10131) on 08-03-2017, 05:16 AM:
yeah, very excited ![[Smile]](smile.gif)
It's thanks to this forum that I went to QSC, I was looking for the JBL 3677 first.
I hope this small horn will be up to its task.
I was a bit sceptical at first because compared to consumer hifi, these QSC's are really not expensive.
One thing I was wondering: did anybody try the better PA models like KW153, or would that be a stupid idea?
Thanks a lot
Posted by David Buckley (Member # 2600) on 08-03-2017, 04:23 PM:
![[Big Grin]](biggrin.gif)
but if its not worth over doing its not worth doing IMO.
![[beer]](graemlins/beer.gif)
