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Discussion Starter · #1 · (Edited)
Hi,

How I got here is, I started looking at getting some custom speakers built. Researching speaker builds, I got into passive vs active crossovers and how active crossovers are more efficient and split the frequencies better. So then I started looking at various active cross over designs to using DSP to split up the frequencies. Finally, I looked at some quality PA speakers from Yamaha, QSC and others and realized, they already built all the DSP and active crossovers stuff into their PA speakers. In the home use land, we are still dealing with passive crossovers - which - the internet tells me are mostly crappy until you pay really big bucks for quality components and complex designs.

So I started researching why do people put down PA speakers. Top reasons I came across were:
- "They are designed to be loud at the expense of fidelity/quality" - Sure, probably even a decade ago when Class D was a dirty word in the audio industry, manufacturers used Class D amplification in PA systems because it was cheap and plentiful, at the cost of clarity/distortion etc. Modern class D is a different story altogether, I believe. But old memories die hard especially in a hobby where there's so much snake oil. I think the whole argument on this point goes back to whether you still believe Class A/B is massively superior to modern Class D (reminds me of how diesel is still a dirty word in the US whereas rest of world has had CRDI or DI diesel motors for decades now)

- "They are designed to be loud" part 2 - There seems to be a notion that PA speakers are somehow designed to put out their power in a large room only and somehow, they would be awful at close quarters. To me, that is like saying, a car designed to go 250mph won't do 10mph so well. I don't have a lot of experience with audio speaker theory but I do have lots of experience with radio antenna design and a lot of principles are the same from wave theory. I cannot imagine how you would design an antenna that would dump all its power far away only and nothing in the near field (with due consideration to wavelengths since those are very different in radio vs audio). Any energy radiating device will dump most of it's power closest to the emitting component. Sure, like with antennas, you can play with directivity but not amplitude.

- "They are designed to be loud" part 3 - Sure, some PA speaker designs don't have dedicated HF/MF/LF woofers/drivers. Like the Yamaha DSR115 or 215 have dual woofers only apparently, no tweeter or mid-range woofer. But then there are designs like the QSC KW153 that is a 3-way design with one component for each range.

- "High end HiFi speakers are $$$ so they must be better than cheaper PA speakers" - No scientific theory here but my limited training in economics says the price differences are based on what the market will pay for a given product, not what it should or what is costs to produce the product. The PA market is price sensitive because artists/bands count equipment to be cost of doing business. The mid/high end audiophile market probably plays more to people's vanities than anything else (like speaker cabinet is made from the rare wood of a tree that grows once in 10 years in Siberia). So while you can sell a few pairs for $5k audiophile speakers, the vast majority of PA business, aka your neighbourhood starving artist, will bolt at those price tags.

- "that frequency response thing" - Actually, I didn't read much about it until I started writing this post and then I came across this article (warning, vendor written article but should be easy to cross check the content for errors):
https://www.prosoundweb.com/channels/av/3_db_or_-6_db_whats_the_difference/

^^ I think QSC is pointing at Klipsch :D Because coincidentally, as I was researching frequency response, I pulled specs for QSC KW153 and Klipsch RF-280F (ok, at this point, I should point out that I have no affiliation whatsoever with any audio vendor other than being the owner of a pair of Klipsch speakers and no QSC speakers).

Back the point about frequency response, another article informs me that "none of these frequency response ranges can be compared".
https://www.audioholics.com/loudspeaker-design/understanding-loudspeaker-frequency-response

So why aren't home audio manufacturers making more of the PA style speakers? I will hazard a guess:
- A lot of current ecosystem assumes you have passive speakers. For example, home audio receivers, except for mid-high end ones, do not even have preamp outs (warning: some like Yamaha's mid level have pre-outs but they aren't good enough to drive an amp as I found out, unfortunately).
- Manufacturers have production lines and marketing channels setup for passive speakers.
- Passive speakers probably cost a lot less than active speakers since passives do not have DSP or amplifiers so consequently have much higher margins. Why make less money when you can make more? lol

Maybe DSP driven speakers like Sonos that are eating the lunch of likes of JBL and Klipsch in the home enthusiast market will change that. I see most major brands have some powered speakers now but isn't clear if they are just amp+passive speaker in a box or actually individually DSP driven amp-ed speakers.

Yes, I know what the wise have to say and yes, I am headed to a Guitar center to see if I can audition a nice pair of PA speakers but I don't think I will ever get to audition a mid/high end HiFi speaker pair next to a PA speaker pair in A/B testing setup - hence this thread and the polite invitation to share your thoughts :D

So the big question: given the state of modern electronics, should there be a quality difference between so claimed HiFi speakers vs PA speakers?

Edit: The more I read on the topic, the more it seems to be about DSP - that is - modern PA speakers incorporate DSP (not sure to what extent though, depends on model/manufacturer) vs passive speaker setups usually lack any DSP provided benefits.
 

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So the big question: given the state of modern electronics, should there be a quality difference between so claimed HiFi speakers vs PA speakers?
Most of the 'quality' differences are more audiophile ignorance than actuality.
There have been lots of advances in driver and horn/WG design over the last couple of decades and they have been mainly driven by the pro end of the market who need to provide maximum SPL + SQ for the minimum price. One example is driver cooling. Up until recently hifi driver manufacturers showed no interest in it as they thought it was a non issue. In PA, having a speaker go into power compression of 3dB because of heating means both a loss of dynamic response and double the amplifier power to get the same SPL as a cool driver.


Home speakers suffer from another issue; WAF. If you look at almost all designs they're narrow and have relatively small drivers and are as small as possible. Good, easy sounding dynamics come from larger drivers loping along as well as the higher efficiency they generally bring. But they tend to be wide and large.



I don't buy pro systems, but have been designing and building speakers with predominantly pro drivers as well as DSP for about a decade and a half. With a few limitations, I won't go back to hifi gear, and I don't even bother with passive xovers anymore. DSP has completely changed the way it's possible to design; no longer are you limited by the driver, but in many cases you can bend it to your will to get the desired result. Audiophiles tend to be scared of DSP as they're concerned it will, to quote someone on another forum, "suck all the life out of the performance", even if they're speakers such as the Kii Three.


My synopsis, based upon engineering and experience, is that a well designed system designed around pro principles with quality drivers and DSP, will eat the lunch of any passive hifi speaker system I've ever heard. With economies of scale, they needn't even be expensive; the Behringer B215XL has a good following, as well as the similar Monoprice unit.


I could write for hours on this subject, but back to the grindstone....
 

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A few thoughts on that subject,

Very true that PA speakers are built to be as efficient as possible to be as loud as possible--no one can deny that! The other massive factor is they have to be reliable, take a beating both electrically and physically as they are moved from gig to gig. The other factor generally not thought of is the weight of the speakers--they have to be moved around gig to gig and 150 pound speakers get old quickly. (Ask me how I know!)

A good example to look at is JTR speakers, both the Neosis 3TX and the 212HTR use the exact same coaxial two-way compression driver but the Neosis is their PA speaker and the HTR is their HT speaker. The PA version crosses the two way compression driver at 450Hz while the HT version crosses lower at 360 Hz. The reasoning is the PA speaker will be driven with more power for much longer periods of time than the HT speaker will. To protect the $750 each compression driver, the PA version crosses over higher in frequency to prevent damage to it.

The PA version takes a small hit in sound quality to increase reliability at high (over 130dB) SPLs. A lot of people complain about the sound quality issues of 2-way 15 inch PA speakers--and they are right for the most part. Their issue is generally speaking, a 15" driver should not crossover higher than 1 KHz because the driver will beam (narrow the dispersion) and not match up with the dispersion of the horn dispersion. The size, weight and cost of a compression driver that can do 1 KHz at high power is quite pricey but if you cross at 1.6 KHz--it cuts the price by 2/3rds and is lighter. However, if you build something like the DIY Sound Group's Fusion 15 which IS a 15" two-way, it crosses over at 1 KHz and sounds incredible. The DNA-360/B&C DE250 is not rated to go down to 1 KHz but can with the proper loading from the 15" SEOS horn. I would not use Fusion 15's for full blast PA because it would probably blow the compression driver--but for HT use there will be no reliability problems.

With speakers, design matters a lot but people concentrate on the drivers. Generally speaking, you don't hear about threads on AVS discussing filter types or how steep of filters to use--that is more for actual speaker builders and not consumers. Take the most expensive drivers in the world, build a 3 inch thick cabinet out of baltic birch and rubber composite yet screw up the design, you have a pile of blown drivers and really expensive firewood for your efforts. The crossover is key with speaker designs, you ignore the rules and sound quality declines.

It is not the PA driver's "fault", it has to do with the design if they sacrifice sound quality for things like cost, durability and weight. The reason 15" two-ways are so popular is lower cost of two-ways, lighter weight and very high durability. If they drop the crossover from 2KHz or 1.6KHz down to 1KHz, they will need a very expensive 2" throat driver to handle the power. This can lead to issues above around 15KHz because of the size of the dome in the compression driver but such is the game. A lot of 15" three-ways would be cheaper than a perfectly designed 15" two-way. Some of those 2" compression drivers run $300 each and go much higher--you can get a really good $40 compression driver but it has to be crossed higher to maintain durability. You generally won't have feedback from mics in a home system but it happens with PA quite often.

A good compromise is use a 12" two-way with a 1.3KHz crossover point. Sure, the compression driver will cost double the price to handle 1.3 KHz but the 12" won't have issues with beaming either. You gain sound quality AND keep most of the durability while keeping the price reasonable. Sure, you HAVE to use subs with it but most decent PA systems run subs. Heck, a 10" two-way crossing at 1.5 to 1.6KHz would be even better--that cuts the price for the compression driver down and the 10 incher won't beam. You do lose something though, efficiency and maximum SPL capability and it has to be used with subs.

DSP and multiple amps is a great thing--but not the solution to all of the problems. It helps a lot, is much easier and can protect the drivers better than passive but you can't use DSP to cure inherent problems or limitations of the driver.

In consumer speaker marketing, it is a lot about style, fashion and whatever the consumer wants. They want pretty finishes, at this time really narrow cabinents, exotic cone materials and nothing to look "weird". PA speakers are wide, large and for the most part not easy to hide. They are the opposite of consumer fashion because they have to be to get the efficiency up. Yeah, there was a time when very large, very efficient speakers were used in the home but the 60/70's and into the 80's era is gone. The Bose AM-5 jewel cubes with cute little bass box came out in 1985 and the audio world changed--kicking and screaming but the big stuff went away. KEF used to make outstanding towers like the 104.2 three-way with tweeters, mids and woofers...in the early 90's they came out with the much smaller coaxials and stuck with them because of the "Bose AM-5 effect".

You can't really blame the speaker companies, they just make what people want. Once the DVD rolled out, the HT market took off and most people refused to have a pair of large speakers and forget about five of them!

What I do is use HT speakers that have pro sound drivers inside them. My LCR speakers are less than 2 cubic feet each and I get 98dB or higher at one watt but give up bass response. Funny to have a 54 pound speaker that dies below 60Hz but I give up bass for better efficiency. The subs take care of below 80Hz so anything below 60Hz is a waste of space.

You can get outstanding sound from PA drivers! Many people around the world build their own be it the Beyma pro sound ribbons, JBL compression drivers, BMS coaxial compression drivers, B&C, Eminence, Faital Pro and others. The consumer style is shiny, narrow towers with cones and domes--huge waveguides/horns, large drivers and wide cabinets are not considered "modern". :rolleyes: Some people get actual theater speakers and modify them to improve sound quality. The JBL 1722N is a good example, they pull the dome out of the compression driver and replace it with a BE piece and it crosses over to the dual 15's at 680Hz. Not something I would listen to at 3 or 4 meters but for very large basement theaters--they work well. Look at the JBL M2, it is related to pro sound speakers--that is who paid for the technology. People really like them and they better, they run about $20,000 a pair but include the outboard Crown amps. They look like PA speakers wrapped in pretty wood veneers but they sound great!

Sadly, not many speakers on the market are high efficiency--you figure they would make higher efficiency speakers for HT use with an AVR. You can get them, Power Sound Audio and Klipsch come to mind but they are the exception.

JBL/Harmon could easily come out with very well finished home speakers that have PA drivers in them. However, they need to sell tens of thousands of them to be worthwhile so it depends on demand. If the demand is not there, they won't become available because business is business! Considering that the sales of soundbars keeps increasing every year and "lifestyle" and automotive audio divisions make far more money than consumer audio, I don't expect the shiny cones and domes speakers to change any time soon. Luckily, the PA market has plenty of competition and parts are available so we can roll our own.

I was doing PA systems 25 years ago, I find the vast improvement in sound quality to be staggering as competition improves the breed. Synergy horns, Oblate Spheroid horns, coaxial compression drivers, neodymium magets, high power/high efficiency ribbons and software modeling sure has come a long way in 25 years. Back then, my Class D amp cost 25% MORE than Class A/B and we don't want to talk about DSP :eek:

The extra bonus when using pro sound drivers is much less snake oil, marketing, fan boys and mysticism are involved with pro gear--as it should be. Enjoy looking around at the pro gear, make sure to check the equipment specifically made for smaller theaters....it should be a better match for using in a home VS the ultra-durable PA stuff. Enjoy! :)
 

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A few thoughts on that subject,
Nice post!

- "that frequency response thing" - Actually, I didn't read much about it until I started writing this post and then I came across this article (warning, vendor written article but should be easy to cross check the content for errors):
https://www.prosoundweb.com/channels/av/3_db_or_-6_db_whats_the_difference/

^^ I think QSC is pointing at Klipsch :D Because coincidentally, as I was researching frequency response, I pulled specs for QSC KW153 and Klipsch RF-280F (ok, at this point, I should point out that I have no affiliation whatsoever with any audio vendor other than being the owner of a pair of Klipsch speakers and no QSC speakers).

Back the point about frequency response, another article informs me that "none of these frequency response ranges can be compared".
https://www.audioholics.com/loudspeaker-design/understanding-loudspeaker-frequency-response
Neither of those articles is helpful as to how FR relates to SQ. Simple on-axis FR measurements are incapable of providing the information necessary to speculate how they will sound in a room. Even if you COULD compare all those FR measurements talked about in that audioholics article, it wouldn't tell you want you want to know.

Dr. Floyd Toole has pulled together the most convincing scientific argument for how to utilize measurements that correlate to SQ. Determining listener preference, and then correlating that to measurements, Dr. Toole has developed the "spinorama" that combines many different anechoic measurements that were found to correlate to listener preference. These measurements can be compared and reasonable judgements can be made. They were adopted as a measurement standard: Consumer Electronics Association's “Standard Method of Measurement for In-Home Loudspeakers” (CEA-2034). If more companies adopt the standard, comparing loudspeakers will be much easier.

Bottom line though, is that behind an acoustically transparent wall, speakers can only be judged by their sound quality. Dr. Toole's research showed very clearly that labels, such as PA/Hifi/High-end, have nothing to do with SQ :).
 

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Speaking of sheep in a wolf's skin, Unison Research has some fancy PA speakers that are pretending to be HiFi, both by looks and price. :D:D
 

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Interesting discussion, but to put it bluntly, "never the twain shall meet". Consumer oriented speakers will always be about what the consumer wants. That ISN'T giant boxes in the living room!
 

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Discussion Starter · #7 ·
Thanks for the responses. Been meaning to post a more detailed response but thought I’d jump in and post a quick one (and show that I am keenly following the thread).

I went to Guitar Center and demo-ed the QSC KW153. Unfortunately, they had a single speakers for demo and the sales guy managed to hook up iPhone only, not the mixer or any quality source. And, the demo setup was less than ideal. Still, I could perceive it sounded very different from my pair of Cerwin Vega XLS215 that I have in my home theater and the Cambridge SoundWorks Towers that I have in the living room. Now, to be fair, all I could tell was they sounded different and definitely I could feel the audio, just at 8 feet distance even when they were at 1/4th output. I am probably going to rent them (nice thing with PA gear) to test them side by side with my current speakers since I don’t think there is any other good way of testing them in the store.

Why the QSC? There are few other big brand name 3-way PA speakers - Electric Voice and Presonus (JBL, Yamaha and others mostly I have 2-ways and not as modern in design, I believe). But after going over several forums, I deduced the QSC are as good as any, if not better. Couple of other dealers I contacted in the SF Bay Area didn’t even have any 3-ways for demo :(

While was walking out of Guitar Center, I tried the Adam A7x. And, I was really impressed - not necessarily by the sonic quality but by the virtual sound stage they created. Right before I tried the A7x, I tried the cheaper version T7V. The T7V were ok nothing special and they were placed right next to the A7x. Then the sales guy switched to the A7x (same song playing from his iPhone) and suddenly the music came alive. A virtual sound stage came up between the two speakers and I could “see” the two vocalists separate in the song, one at the center and the second a little off center. I imagine that’s all DSP at work. That set me thinking more about DSP and if I could add an external DSP module to my existing setup and improve imaging. After going over miniDSP and Dirac, currently looking at some open source dsp software to see if I can tweak or play with my current setup to produce a different outcome. End of “quick” update


Sent from my iPhone using Tapatalk
 

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^^ Post your impressions of the QSCs after you've tried them for a few days.
 

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Greetings,


This is my first post on this forum. Let me preface this by letting you know that I'm an audio professional. My company provides live sound production services as well as audio / visual design and installation services for churches, schools, theaters, etc... I also have many years of experience as a recording studio engineer, and as a touring musician, although my focus in now on live sound and system design. As I spend almost all of my time immersed in the "pro audio" world, I rarely have time to keep up with the rapidly changing world of home audio and home theater. I stumbled on to this forum a while back and found it not only informative and entertaining, but also a great way to keep up with the goings on in the consumer home theater world. While I certainly appreciate high quality audio production and reproduction, I will not refer to myself as an audiophile, because to be quite blunt, that label is not necessarily considered a "badge of honer" in the pro audio realm, if you know what I mean. :) That said, this thread caught my attention and compelled me to respond.



The OP mentioned that he curious as to why "pro" speakers get a bad rap among "audiophiles". A9X-308 responded that most of the quality differences are more audiophile ignorance than actuality and he couldn't have been more correct. For all practical purposes, speakers are speakers. they are transducers that convert one form of energy to a different form of energy. The basic principles of loudspeaker technology have been around for a very long time and haven't changed all that much. What has changed is the quality of materials being used, manufacturing techniques and of course computing power that allows for much more exacting measurements, sophisticated design criteria, experimentation and signal processing. There is more to it however.



When you go to a live concert (assuming everything is amplified), all the elements of the signal chain, from the instruments and amplifiers on stage, to the microphones and loudspeakers in use are all subject to the same laws of physics. As one could reasonably expect, the influence of a 2500 seat auditorium on how a sound system behaves, is considerably more drastic than the acoustic issues presented by a typical home theater or family room. Long decay times, reflective surfaces, high ambient noise levels and low frequency problems that only occur in very large rooms, all effect the performance of the sound system in use. Add in spill from the stage volume, stage monitors, multiple open microphones picking it all up and reintroducing it into the signal chain, etc and you can begin to see that it gets pretty messy, pretty quickly. Advances in speaker technology, and DSP have allowed for much higher quality sound in live performances, but understand that the recordings (both music and movie soundtracks) we all purchase, were produced in highly controlled environments, by highly skilled engineers using very sophisticated technology and massaged to within an inch of their lives before being released to the public. There is no bigger influence on the quality of sound being reproduced or amplified than the source itself, and you can't, for all practical purposes, separate the source from the acoustic environment it resides in. It's easy to blame the speakers for what someone perceives as mediocre or even bad sound, but the reality is that there are so many outliers in a concert sound environment, that to simply assign the blame for bad sound on "pro" speakers is a non starter. When the source is in an acoustically friendly recording studio or sound stage, it's much easier to maintain the integrity of the original sound of that source than when it's in a large concert venue. That said, we've all been victimized by bad live sound far too often. Yes, there are lots of bad sound engineers out there.



With regard to the QSC KW153 speakers mentioned by the OP, they are what's considered MI grade gear by pro standards. MI being short for "musical instrument"- as in available for purchase in music stores like Guitar Center, etc. This is not to say they aren't of good quality, many MI grade products are actually quite good. QSC makes very good MI grade products, but they also produce true pro grade equipment that you will not see in a music store. As with most manufacturers, the truly professional products are only available for purchase from factory authorized dealers. I am a QSC dealer (and many other brands as well) and have used KW153s in numerous situations. The KW153 is a good sounding loudspeaker. Personally, I wouldn't want it in my home theater for several reasons. It's really big, heavy and ugly (by HT standards) and it's got a bunch of features that are pointless for HT use. Could it be used? Certainly. Do I need the dual input channels and high pass outputs for HT? Nope. So why pay for it? Do I need handles? Nope. Do I need steel perforated grills? Nope. Will it make massive amounts of SPL? You bet. Do you really need a speaker with a maximum output of 134dB in your living room? I suppose some would say "Hell yes!" but not this guy. My hearing takes enough abuse as it is. I just want to enjoy the movie. When I purchase for my production inventory, there are many factors that I have to consider when deciding what to buy. First and foremost is return on investment. Will it make me money? How much truck space does it take up? How easy is it to deploy? Can I move it myself, or do I have to hire more crew? What are the dispersion characteristics? How much amperage does it draw? Is it loud enough? You get the idea


The ADAM A7X that was mentioned in the original post is an entirely different story. This is a high quality, pro level reference monitor designed for recording studio use. You could certainly achieve stunning sound if you built your HT around them, assuming they're set up correctly. Bear in mind that these are nearfield monitors intended to be used at close distances so your mileage may vary if you decide to use studio monitors in a larger HT room. Good studio monitors are designed from square one with one thing in mind. Accuracy and transparency. Recording studio engineers need to hear everything in it's purest form. Studio monitors take some time to get used to. They are not necessarily "fun" to listen to. They generally have a very flat frequency response and can sound sterile and too clinical for some people. Set up correctly however, they can reveal details that many speakers simply cannot. Adam makes (or at least they did at one point) home speakers that share the same components as their highly regarded studio monitors. I have not seen them for sale anywhere in the US, but I haven't actually looked that hard either. Not sure if they still make them or not.



DSP is certainly one of the most valuable tools used in setting up large scale concert sound systems. It has made the tasks of time alignment, phase alignment, gain shading, EQ, coverage parameters and system limiting a much more exact science. The DSP being used by HT equipment manufacturers has it's roots in the pro audio world. Much like racing technology eventually finds its way into the family car. The application of this technology in the HT market has been simplified, with good reason, so that the masses can have a stab at calibrating their systems for the acoustic environment that they are used in. For those that spend time in forums like this, you can likely never have too much access to the parameters used to set up your system to your liking, but for the masses that just want to watch movies with decent sound, it can be somewhat intimidating. I will say that when I purchased my first AVR (a Yamaha) with onboard DSP, I compared the data with my "pro" measurement rigs (Smaart and Spectrafoo) and was pleasantly surprised at how accurate it was.



Well, I just read through this and didn't realize it was turning into a novel, but hopefully readers here find these types of discussions as interesting as I do. I hope I'm not coming off as a "know it all" (I'm certainly not) or a "pro snob" but as someone that is lucky enough to make a living doing what I love to do. Make and reproduce music and sound for other peoples enjoyment. Lastly, I'll mention that for those interested, you should check out prosoundweb. It's a forum like this, frequented by some of the best professional sound engineers on the planet. You can peruse the forums without registering, but if you decide to register, you must use your real full name as the forum is strictly moderated to keep the content up to standards. It's a great source of advanced technical knowledge for all things audio.


Cheers.
 

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The ADAM A7X that was mentioned in the original post is an entirely different story. This is a high quality, pro level reference monitor designed for recording studio use. You could certainly achieve stunning sound if you built your HT around them, assuming they're set up correctly. Bear in mind that these are nearfield monitors intended to be used at close distances so your mileage may vary if you decide to use studio monitors in a larger HT room. Good studio monitors are designed from square one with one thing in mind. Accuracy and transparency. Recording studio engineers need to hear everything in it's purest form. Studio monitors take some time to get used to. They are not necessarily "fun" to listen to. They generally have a very flat frequency response and can sound sterile and too clinical for some people. Set up correctly however, they can reveal details that many speakers simply cannot. Adam makes (or at least they did at one point) home speakers that share the same components as their highly regarded studio monitors. I have not seen them for sale anywhere in the US, but I haven't actually looked that hard either. Not sure if they still make them or not.



DSP is certainly one of the most valuable tools used in setting up large scale concert sound systems. It has made the tasks of time alignment, phase alignment, gain shading, EQ, coverage parameters and system limiting a much more exact science. The DSP being used by HT equipment manufacturers has it's roots in the pro audio world. Much like racing technology eventually finds its way into the family car. The application of this technology in the HT market has been simplified, with good reason, so that the masses can have a stab at calibrating their systems for the acoustic environment that they are used in. For those that spend time in forums like this, you can likely never have too much access to the parameters used to set up your system to your liking, but for the masses that just want to watch movies with decent sound, it can be somewhat intimidating. I will say that when I purchased my first AVR (a Yamaha) with onboard DSP, I compared the data with my "pro" measurement rigs (Smaart and Spectrafoo) and was pleasantly surprised at how accurate it was.
Welcome to the forums! It's good to have folks with industry experience around here. This forum is one of the few consumer sites, on the whole, that is truly more science based than "audiophile".

The advantages of DSP for room correction, like in the Yamaha AVR you mentioned, is fairly ubiquitous in the consumer space these days. But the consumer side has not embraced DSP for active loudspeakers. As well, finding objectively accurate, reference capable loudspeakers is difficult on the consumer side. As a result, you'll find some members here with professional loudspeakers or that design their own(DIY).

As to SPL, I like significant headroom in my system and the effortlessness of very capable speakers is evident with even moderate SPL in my experience. I also like the fact that the chances of me ever blowing a driver is slim to none, so I personally use pro gear. But many find it overkill, and I can understand that. To each his own.
 

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Thanks for the welcome Goodoc. Much appreciated. I've been lurking around these forums for about a month and must say that I'm liking the general vibe of the forums. There are clearly a lot of knowledgeable folks offering good, solid advice and answers to many of the posted questions. Not nearly as much "voodoo magic audiophile nonsense" as I expected there would be.


One thing that I meant to address in my previous post and didn't was with regards to this, from the OP.


"While was walking out of Guitar Center, I tried the Adam A7x. And, I was really impressed - not necessarily by the sonic quality but by the virtual sound stage they created. Right before I tried the A7x, I tried the cheaper version T7V. The T7V were ok nothing special and they were placed right next to the A7x. Then the sales guy switched to the A7x (same song playing from his iPhone) and suddenly the music came alive. A virtual sound stage came up between the two speakers and I could “see” the two vocalists separate in the song, one at the center and the second a little off center. I imagine that’s all DSP at work. That set me thinking more about DSP and if I could add an external DSP module to my existing setup and improve imaging. "

The Adam A7X, while an active bi-amped speaker, does not have DSP onboard. It has physical controls for input sensitivity, a high shelf at 5k, a low shelf at 300hz and a tweeter gain adjustment. The crossover network is part of the internal electronics, and I assume limiters for driver protection (no info about limiters on Adam website), but no configurable onboard DSP.
The substantial differences you heard when switching between the A7X and the less expensive T7V could be chalked up to a number of factors, but remember, the T7V was built to get Adam into the home studio / prosumer markets. That's where the real money is. The A7X is a very refined design and is simply too expensive for that crowd.

As for onboard DSP, the most common parameters in pro level active speakers control high pass filter settings, phase (actually polarity), alignment delay, input sensitivity and preset EQ settings. The latest trend is the inclusion of FIR filters (finite impulse response) which allow for improved phase coherency in the crossover region. That said, stand alone system processors that can manage large multi element sound systems are the most commonly used in live sound applications of any appreciable scale.

DSP in line array systems gets more complex with control for mid and high frequency compensation based on the length (number of speakers) of the array and the spay angles in use, but this is well outside the scope of this thread.
 

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Welcome to the forums! It's good to have folks with industry experience around here. This forum is one of the few consumer sites, on the whole, that is truly more science based than "audiophile".

The advantages of DSP for room correction, like in the Yamaha AVR you mentioned, is fairly ubiquitous in the consumer space these days. But the consumer side has not embraced DSP for active loudspeakers. As well, finding objectively accurate, reference capable loudspeakers is difficult on the consumer side. As a result, you'll find some members here with professional loudspeakers or that design their own(DIY).

As to SPL, I like significant headroom in my system and the effortlessness of very capable speakers is evident with even moderate SPL in my experience. I also like the fact that the chances of me ever blowing a driver is slim to none, so I personally use pro gear. But many find it overkill, and I can understand that. To each his own.
Goodoc, I agree that headroom is crtical. High SPL is much more pleasing to listen to when the system isn't pushed to the extremes of it's performance limits. I routinely mix live shows at 95dB (a weighted/slow) 100' feet from the stage and having enough headroom left in the system to achieve clean transients of 100-105dBa makes all the difference. I'm not a "my way or the highway" kind of guy. To each his own for sure, but a living room full of KW153s might be considered bringing a bazooka to a knife fight for all practical purposes. But hey, who am I to judge practical? That dude from Stereophile spend 30 grand on a tone arm! Does that make his $4000 power cable seem like a bargain? Never mind that the same electricity just passed through the contractor grade wiring in his house.
 

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I Have hear some inexpensive as far as PA speakers go Technical Pro VRTX and VRTXL speakers and thought they sounded more than decent nough for home use. Yo'd have to be single or have a very understanding cohabitational partner to have them in a living room though.

TBH they reminded me of klipsch floorstanders in sound. Just bigger and more drivers and of course more bass.
 

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The latest trend is the inclusion of FIR filters (finite impulse response) which allow for improved phase coherency in the crossover region. That said, stand alone system processors that can manage large multi element sound systems are the most commonly used in live sound applications of any appreciable scale.
Come and visit the DIY section here and you might be surprised how many of us use DSP active systems and how complex some of them are. My 2ch/HT system has 6 active 3 way speakers all with DSP, and the 5 subs and shaker have their own DSP and the bedroom speakers I'm developing are also 3 way active. My study has LSR305s. I've been using DSP since 2001 or so, both live, my BG system and home. FIR has some benefits but the two main drawbacks are off axis performance and the processing lag for longer tap filters messing with V/A sync.

Many, many others here use DSP for multiple subs whether an outboard unit such as an MD or the integrated unit in some pro amps.


Anyway, welcome, you may find yourself among some nerds here.
 

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Come and visit the DIY section here and you might be surprised how many of us use DSP active systems and how complex some of them are. My 2ch/HT system has 6 active 3 way speakers all with DSP, and the 5 subs and shaker have their own DSP and the bedroom speakers I'm developing are also 3 way active. My study has LSR305s. I've been using DSP since 2001 or so, both live, my BG system and home. FIR has some benefits but the two main drawbacks are off axis performance and the processing lag for longer tap filters messing with V/A sync.

Many, many others here use DSP for multiple subs whether an outboard unit such as an MD or the integrated unit in some pro amps.


Anyway, welcome, you may find yourself among some nerds here.
Thanks for the welcome. High percentage of "nerds" on a site like this is to be expected. In fact, I'd be somewhat dissappointed if that weren't the case! I've been checking out posts all over the forums here including the DIY forums. As with any hobby, there are those who really enjoy diving into the deep end, so I'm not surprised at the complexity of some of the system folks put together. There also seems to be quite a bit of advanced knowledge coming from many of the forum members. That's awesome to see. While I'm a professional audio engineer, I come at the profession primarily from the music/creative side of the equation not the strictly technical / engineering side. While I certainly have technical knowledge, I get paid to deploy and operate the equipment, not design it, so I'm quite sure that there are many forum members here with much deeper knowledge of circuit design and other concepts that fall under the electrical engineering umbrella than I possess. I leave the number crunching to the high level nerds and concentrate on setting up systems in hostile acoustic environments and mixing music.



So far, I'm digging these forums. Lots of good questions, suggestions and sharing of ideas. Haven't seen any flaming, insults or comparing d*ck size yet. Refreshing!
 

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Haven't seen any flaming, insults or comparing d*ck size yet. Refreshing!
You will from time to time it just depends on the subject. There are a few "hot button" topics around here, but it almost always remains civil. I think most of the people here are just fans of the hobby, and frankly there are some members with truly CRAZY setup's or they would be to an outsider. What one member has 86Kw of burst power on tap for his room, there are professionals that have multi million dollar custom theaters, custom speaker designers, and of course all the DIY and DIYSG people. I got on here several years ago when I was looking to buy a TV and have been a daily visitor since then.
 

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Discussion Starter · #20 · (Edited)
Rented a pair of QSC KW153 for the weekend. Let me know if anyone has ideas on testing them side by side with my Cerwin Vega XLS 215.

My setup is:
Integra DHC 80.3 (XLR our) => Crown XLS 1500 => Cerwin Vegas

I have been testing/comparing the QSC with LF set to “Normal” and HF set to “Flat” and both gain knobs set to 0 dB.

On the Crown XLS 1500, gain is set to max.

For movies, I played “Battle LA” via BluRay and “Monsters vs Aliens” via Netflix.

For music, “Faith” by George Michael via CD and “Ave Maria” by Mary J Newman via iTunes (vbr mp3)

I turned off all other channels for testing by deleting the speakers from the AVR.

Tomorrow, I will get a XLR switch to do A/B switching without physical connecting/disconnecting cables.

Room Recording studio Audio equipment Loudspeaker Technology


Sent from my iPhone using Tapatalk
 
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