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Author Topic: Which subs to buy? Paralysis by analysis  (Read 19021 times)

Ivan Beaver

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Re: Which subs to buy? Paralysis by analysis
« Reply #20 on: October 05, 2014, 09:23:36 pm »

Agree, and FWIW I don’t think its good practice either, just about every other manufacture specifies 1 watt per meter referenced to the nominal impedance. E.g. - 2.83 volts for 8 ohms and 2.0 volts for 4 ohms.

We measure how powerful speakers (and amplifiers) are in watts, and it’s logical to compare their efficiency relative to watts.
 
I understand impedance, and all the issues Ivan discusses.  I just think what Danley is doing can be misleading, especially for those people who don’t fully understand the specifications.
I would argue that specs without measured responses are MUCH MORE misleading.

We state the measurement condition-the voltage-show the impedance curve-the freq response etc.

If somebody does not understand these simple things-then maybe they should-if they are going to be in this business.

Amps-speakers-impedance etc can be very intertwined and there are lots of things that can easily mislead people (such as stating the -3dB point that is no where near the actual freq stated-ora sensitivity measured outside of the intended bandwidth), but yet people just "swallow it hook line and sinker" without questioning it or actually measuring it.

Why does little or not data seem to impress people?  I would be more concerned about no specs-than specs that are stated pretty well.

But that is just me.
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Ivan Beaver
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Ray Aberle

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Re: Which subs to buy? Paralysis by analysis
« Reply #21 on: October 05, 2014, 09:24:18 pm »

I don't have anything "special" on my computer-just the normal stuff-whatever that is.

Are you trying to use something "special" or different"

It would be nice to know what operating system-what browser you are using so problems like this can be addressed.  without that knowledge-there is no way to even think about looking at the problem.
Just Apple Safari, v 5.1.10, Mac OSX 10.6.8, iMac G5, 2.4GHz Intel Core 2 Duo, 2GB RAM. Clicked on the link you posted, that screen shot is the result.
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Tom Danley

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Re: Which subs to buy? Paralysis by analysis
« Reply #22 on: October 05, 2014, 09:25:53 pm »

My classic rock band has been in the market for subs for the past 6 months, but every time we think we know what we want we find out about another sub that may work better for us.  We have Peavey QW4 for mains.  One of the main problems is that we can't find anywhere to listen to most of the subs, let alone A/B them.  We have looked at Peavey QW218, then VR 218, JBL SRX 728, STX 828, EV Qrx 218, Yorkville LS 1208, LS 2104 (which seems to be a real good sub on paper, but we can't find much information about it) Danley TH 118 and JTR Orbit Shifter.  My impression from reading comments on the internet is that the Danley may be a cut above the rest.  The sensitivity is listed at 108db 1w 1m.  Does this mean that it would take only 25% of the power to produce the same spl as a sub with 102db sensitivity? (or am I not understanding the 3db=2x the power rule).  Saving on power amps would certainly be a plus.  Right now we are leaning towards new VR 218 or used TH118.  We would appreciate some help from any of you who have heard these subs.

thank you

Hi Mark
Compare as many of your choices side by side if you can with the variety of music you will play. This is far and away the best way to get a feel for the differences in sound quality and output of your choices.               Be skeptical of spec sheets as some are more wishful marketing than technical information and ultimately it’s what something does in your application that matters. Bang for the buck.

Hi David
Yes we use 2.8V as it is easy to measure where 1 Watt (the engineering Watt a measure of power or work, not loudspeaker watt) is difficult and depends on the impedance at that frequency.  The rest of our audio chain from the microphone to amplifier gain is Voltage referenced system and so is a more logical choice in a Synaudcon / engineering frame of reference. 

“Most of my use for spec sheets anymore is to find out how much something weighs, so I can tell someone else how heavy it is so they can lift it for me... And to maybe get an idea of how to power something.”

This spec issue is exactly why I believe it’s important to have a more technical information, not just for how much it weighs but also what It does acoustically.     The idea is to use the same criteria one might find in the specification of a transistor or fastener where one can design something using that engineering information.       Sure there are companies that don’t supply anything other than size and weight, many don’t supply response curves, no impedance curve, some even over state the actual usable SPL by 10 or more times and so on.
     
Maybe that is “what we need to do” to be “comparable” in this market, but it is not something I want to do, I had been sure what we should do is provide more information and for those who can interpret it, even a response curve taken in repeatable conditions.

The point is being able to design based on that information, for example, if you measure a subwoofer at 10 meters and calculate the 1m sensitivity, you have a figure which will allow the SPL to predicted at say 50 or 100 meters while an actual sensitivity curve taken at 1 meter for a large subwoofer may be off at larger distances.
 
“But typically I already know that from the last job.”

And unless one has some kind of technical information regarding what the thing does, that only tells you about what was used in the last job, it does not allow one to compare one thing to another.  Unless one is spending some ones else’s money, somewhere close to the surface should be the bang for the buck concern.   Short of a side by side comparison of two choices, the technical data is the only thing one has.

“You can't tell how good a speaker sounds from a spec sheet. I have heard speakers with really good specs sound really bad.”

One of Richard Heysers lifelong goals was to tie what one measured to what one heard and he never arrived at the “transform” he was looking for.  Part of the problem there is our “sense of hearing” is also tied into what you see and what you know.   
There are also plenty of uses for loudspeakers that are not faithful but sound acceptable even right.     

On the other hand, if / when one is trying to find a signal faithful loudspeaker, the same approach that was used in the past will work here. Listen to a loudspeaker through a measurement grade microphone through good headphones or go a step farther and make a generation loss recording outdoors.  When you find a loudspeaker that can survive just two or three generations before sounding bad, you will have a fine sounding speaker for music and voice reproduction, “signal faithful”. 

 Ray, that is really weird, if you can tell me what you viewed that with, I would like to pass that on the the web site people, clearly that if funky.

Bob, if a single ended subjective assessment is “enough”, there is no need to compare to anything else. if not, then there might be a reason to compare to other possibilities some of which work on different principals and have different acoustic signatures and responses. 

Hi Peter
I am not sure you see what Ivan sees, he measures a lot of loudspeakers, has set up and tuned well over a thousand large installations with many brands of products and taken a bunch of Synaudcon / engineering classes and that is part of what drives him crazy about loudspeaker specs and stuff.  Be glad he can’t talk about specific cases he has run into.   Fwiw,  I have seen loudspeakers who’s impedances dip way below 5 Ohms and yet are still specified as a nominal 8 ohm impedance. 
What is more misleading supplying an impedance curve or saying a speaker that even touches 4 Ohms is an 8 ohm load?         
What conveys more engineering information an impedance curve showing the peaks and dips or a single number?
Given how few people measure anything nowadays, i wonder how important it is to provide engineering information?. 
Best,
Tom Danley
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Ray Aberle

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Re: Which subs to buy? Paralysis by analysis
« Reply #23 on: October 05, 2014, 09:27:18 pm »

I would argue that specs without measured responses are MUCH MORE misleading.

We state the measurement condition-the voltage-show the impedance curve-the freq response etc.

If somebody does not understand these simple things-then maybe they should-if they are going to be in this business.

Amps-speakers-impedance etc can be very intertwined and there are lots of things that can easily mislead people (such as stating the -3dB point that is no where near the actual freq stated-ora sensitivity measured outside of the intended bandwidth), but yet people just "swallow it hook line and sinker" without questioning it or actually measuring it.

Why does little or not data seem to impress people?  I would be more concerned about no specs-than specs that are stated pretty well.

But that is just me.

well, I think it could be likened to when you buy a car-- do you shop based on horsepower or MPG? Both measure the output or efficiency of the car's engine, just in different ways... they're both useful numbers, just not really interchangeable. MPG can vary based on external conditions, but horsepower is constant-- but people understand MPG better.

Tom, thanks for the shoutout (woo hoO!) -- see my post replying to Ivan. Not sure what happened. But those are my specs there-- nothing TOOO far out of date.
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Kelcema Audio
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Ivan Beaver

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Re: Which subs to buy? Paralysis by analysis
« Reply #24 on: October 05, 2014, 10:01:20 pm »

well, I think it could be likened to when you buy a car-- do you shop based on horsepower or MPG? Both measure the output or efficiency of the car's engine, just in different ways... they're both useful numbers, just not really interchangeable. MPG can vary based on external conditions, but horsepower is constant-- but people understand MPG better.


I would argue that many buy on horsepower alone.  It depends on what you are looking for and who you are looking to impress with the numbers.

And horsepower alone does not tell how fast a car will go.  It depends on many factors-the weight-aerodynamics-transmission just to name a few.

I would also argue that many people "talk" about watts-but really do not understand what they are saying (but they think they do).

The market just loves those people and they market based on watts.  How many times do you see adds talking about watts vs how many based on usable SPL?

And when I say "usable" I remember one product a few years ago that had a really really high SPL number as the main advertising item.  But the issue was that this figure came from a single peak in the response of the HF driver.  The woofers max SPL was something like 18dB lower.

YEAH-that is what I want-a HF that is 18dB louder than my woofers.  I guess if you have severe hearing loss----------Say what????????

And they are not the only company that does this type of marketing.  Yes they are probably "telling the truth" but not a "useful truth". 

But that does not keep "people who should know better" from going around stating these specs and not even listening to other products because "they can't get as loud".  Yeah-but neither can the product in question-in a "useful" way.

The market understands that most people are stupid when it comes to this-and they simply give them what they "want" to hear/believe.  That is not limited to our industry either.

That does not mean it is right-or useful-but it does help sell product and that is all they are looking for. 

I am sorry to rant about things like this-but it just CONSTANTLY amazes me the number of people that I talk to-see online etc that use these "useless or misleading numbers" as a means to attempt to compare product performance.

And they think they are being "smart" about it. :(  and they somehow convince others who further lower the overall knowledge level and understanding.

Together we can help "raise the bar" to hopefully improve the overall quality of sound and expectations.

But there will be people who still believe you can get a 2,000 watt sound system that runs off of 8 D cell batteries and has some 6" speakers-----------------

No wonder some manufacturers feel like this is "shooting fish in a barrel".
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Mark Monson

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Re: Which subs to buy? Paralysis by analysis
« Reply #25 on: October 05, 2014, 10:08:05 pm »

Really Ivan, WTF, does every reply have to be a sermon?

OP,
Any of the subs you listed will do a decent job for you. I would look towards the SRX728 which are obsolete, but can be found, and will do a very good job. The only thing you may not like about the 728 is the size and weight, but it is a formidable dual 18" cabinet that many of us rely on with great success and very, very few failures. The STX 828 is also a great sub with the same capabilities as the 728. The drivers are not the same, and the 2242 used in the 828 will produce good quality sound at slightly lower frequencies than the 728, but either sub will produce very high quality sound capable of rolling your socks up and down at high levels.


Bob - Thank you for the concise understandable reply.  Thanks to the rest of you for showing me that there is more to this than is first apparent.  It seems like rating subs is a little like religion.  Since I can't hear all of the subs I'm considering, I'll have to decide where to put my "faith"

After reading a lot of opinions regarding high end subs, my impression is that the ones I've listed fall into 3 categories

Good                   db/1w/1m
Peavey QW 218   100
EV QRX 218         102
Yorkville 1208      105

Better
Peavey VR 218   100
JBL SRX 728       98
JBL STX 828       98
Yorkville 2104     98

Best
Danley TH 118   108
JTR Orbit shifter  103

Could those of you who have heard these subs comment on my grouping?  I am leaning towards VR 218 or SRX 728 (If I can find some used).  If the Danley TH 118 is truly a significant step up and if it requires less w/spl (something that is suspect after reading the above posts) then we would probably buy one now and save up to purchase another later.

Again, I appreciate all of the knowledgeable people who are commenting on this

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Peter Morris

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Re: Which subs to buy? Paralysis by analysis
« Reply #26 on: October 05, 2014, 11:46:15 pm »

I would argue that specs without measured responses are MUCH MORE misleading.

We state the measurement condition-the voltage-show the impedance curve-the freq response etc.

If somebody does not understand these simple things-then maybe they should-if they are going to be in this business.

Amps-speakers-impedance etc can be very intertwined and there are lots of things that can easily mislead people (such as stating the -3dB point that is no where near the actual freq stated-ora sensitivity measured outside of the intended bandwidth), but yet people just "swallow it hook line and sinker" without questioning it or actually measuring it.

Why does little or not data seem to impress people?  I would be more concerned about no specs-than specs that are stated pretty well.

But that is just me.

Ivan, nobody is talking about your competition not supply all the information, why did you assume that; most supply frequency response, impedance curves and polar information etc etc.
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Peter Morris

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Re: Which subs to buy? Paralysis by analysis
« Reply #27 on: October 06, 2014, 12:45:58 am »

Hi Mark
Compare as many of your choices side by side if you can with the variety of music you will play. This is far and away the best way to get a feel for the differences in sound quality and output of your choices.               Be skeptical of spec sheets as some are more wishful marketing than technical information and ultimately it’s what something does in your application that matters. Bang for the buck.

Hi David
Yes we use 2.8V as it is easy to measure where 1 Watt (the engineering Watt a measure of power or work, not loudspeaker watt) is difficult and depends on the impedance at that frequency.  The rest of our audio chain from the microphone to amplifier gain is Voltage referenced system and so is a more logical choice in a Synaudcon / engineering frame of reference. 

“Most of my use for spec sheets anymore is to find out how much something weighs, so I can tell someone else how heavy it is so they can lift it for me... And to maybe get an idea of how to power something.”

This spec issue is exactly why I believe it’s important to have a more technical information, not just for how much it weighs but also what It does acoustically.     The idea is to use the same criteria one might find in the specification of a transistor or fastener where one can design something using that engineering information.       Sure there are companies that don’t supply anything other than size and weight, many don’t supply response curves, no impedance curve, some even over state the actual usable SPL by 10 or more times and so on.
     
Maybe that is “what we need to do” to be “comparable” in this market, but it is not something I want to do, I had been sure what we should do is provide more information and for those who can interpret it, even a response curve taken in repeatable conditions.

The point is being able to design based on that information, for example, if you measure a subwoofer at 10 meters and calculate the 1m sensitivity, you have a figure which will allow the SPL to predicted at say 50 or 100 meters while an actual sensitivity curve taken at 1 meter for a large subwoofer may be off at larger distances.
 
“But typically I already know that from the last job.”

And unless one has some kind of technical information regarding what the thing does, that only tells you about what was used in the last job, it does not allow one to compare one thing to another.  Unless one is spending some ones else’s money, somewhere close to the surface should be the bang for the buck concern.   Short of a side by side comparison of two choices, the technical data is the only thing one has.

“You can't tell how good a speaker sounds from a spec sheet. I have heard speakers with really good specs sound really bad.”

One of Richard Heysers lifelong goals was to tie what one measured to what one heard and he never arrived at the “transform” he was looking for.  Part of the problem there is our “sense of hearing” is also tied into what you see and what you know.   
There are also plenty of uses for loudspeakers that are not faithful but sound acceptable even right.     

On the other hand, if / when one is trying to find a signal faithful loudspeaker, the same approach that was used in the past will work here. Listen to a loudspeaker through a measurement grade microphone through good headphones or go a step farther and make a generation loss recording outdoors.  When you find a loudspeaker that can survive just two or three generations before sounding bad, you will have a fine sounding speaker for music and voice reproduction, “signal faithful”. 

 Ray, that is really weird, if you can tell me what you viewed that with, I would like to pass that on the the web site people, clearly that if funky.

Bob, if a single ended subjective assessment is “enough”, there is no need to compare to anything else. if not, then there might be a reason to compare to other possibilities some of which work on different principals and have different acoustic signatures and responses. 

Hi Peter
I am not sure you see what Ivan sees, he measures a lot of loudspeakers, has set up and tuned well over a thousand large installations with many brands of products and taken a bunch of Synaudcon / engineering classes and that is part of what drives him crazy about loudspeaker specs and stuff.  Be glad he can’t talk about specific cases he has run into.   Fwiw,  I have seen loudspeakers who’s impedances dip way below 5 Ohms and yet are still specified as a nominal 8 ohm impedance. 
What is more misleading supplying an impedance curve or saying a speaker that even touches 4 Ohms is an 8 ohm load?         
What conveys more engineering information an impedance curve showing the peaks and dips or a single number?
Given how few people measure anything nowadays, i wonder how important it is to provide engineering information?. 
Best,
Tom Danley

Hi Tom,

I understand all of that, but have a look at Marks post (25). He has assumed your TH118 is rated @ 108 1w/m - its not, its 105 w/m - ref 2 volts @ 4 ohm. The other boxes he is comparing them with are also 4 ohms ref. 2.0 volts. That happened even after David pointed how your boxes are measured.

... and that's an example of my point, and exactly why I think what you are doing with your specifications is misleading.

Don't get me wrong I'm not suggesting that these are not excellent products, in fact I would love some TH118s  :) and it does not change how they perform ... I believe you should specify your box efficiencies with respect to their nominal impedance like everyone else- i.e. 8 ohms ref. 2.83Volts -  4 ohms ref. 2.0 volts.
« Last Edit: October 06, 2014, 05:51:39 am by Peter Morris »
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Mario Pollio

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Re: Which subs to buy? Paralysis by analysis
« Reply #28 on: October 06, 2014, 06:34:10 am »


Not to mention it is difficult to look at spec sheets when they don't download properly. I wish website designers wouldn't require special "somethings" in order to use their sites.....

I have a macbook pro and it does the same thing also when clicking on spec sheets on Danley's website. If you google the product and click on the spec sheet through a google search, for some reason it works.
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Ivan Beaver

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Re: Which subs to buy? Paralysis by analysis
« Reply #29 on: October 06, 2014, 09:05:15 am »

Ivan, nobody is talking about your competition not supply all the information, why did you assume that; most supply frequency response, impedance curves and polar information etc etc.
Sorry, but I would argue that most don't supply that information.

Some do, but most-or at least many (I guess it depends on who falls into the "most" category) do not.

Or some may provide it for some models-but not others.

And we won't even go into how much smoothing and such is used---------------
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Ivan Beaver
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ProSoundWeb Community

Re: Which subs to buy? Paralysis by analysis
« Reply #29 on: October 06, 2014, 09:05:15 am »


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