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Church and H.O.W. – Forums for HOW Sound and AV - Your Displayed Name Must Be Your Real Full Name To Post In The Church and HOW Forums => Church Sound => Topic started by: Jacob Robinson on February 10, 2011, 02:38:42 pm

Title: Quality of Components?
Post by: Jacob Robinson on February 10, 2011, 02:38:42 pm
I am trying to persuade our church to do a PA overhaul so I have went out and gotten several quotes and the last one I got was almost 40% less than the others.  My question is what your opinion of the components that were chosen and the quality of the system as it might work together as a whole.  I know without more details about the acoustics of the church you cannot give too much feedback, but my question is more about the quality of products chosen.

Thank your for your opinions, (I hope this is allowed)

our church is approx.

30' x 75'
8' walls on sides, with gabled ceiling that are 14' in center
We have a full worship band and play a very wide variety of music

Here are the proposed components.

(1) Allen & Heath ZED-436  http://www.allen-heath.com/zed/zed436

(2) DAS Artec 28 (house speakers). . . . .http://www.dasaudio.com/index.asp?pagina=productos&subpagina=1&galeria=176&producto=476&numPagina=2&lang=en

(2) Bag End D10E-I (subs) http://www.fullcompass.com/common/files/2798-D10E-I%20Bag%20End%20specs.pdf

(2) FBT Verve 8M (stage monitors) http://www.fbtusa.net/FBTVerve8mmonitortc.html

(4) FBT Jolly 5RA (Monitors for instruments and individuals) http://www.fbtusa.net/jy5ra.html

(1) Bag End Infra  Processor http://www.bagend.com/bagend/downloads/inframxb.pdf

(1) Driverack PA+ http://www.dbxpro.com/PA+/

(3) Crown XTI-1000 amps http://www.sweetwater.com/store/detail/XTi1000/?gclid=COW3ufGq_qYCFcIKKgodIy-4Zg

(1) Furman PSPROII power manager http://www.furmansound.com/product.php?id=PS-PRO_II





Title: Re: Quality of Components?
Post by: John Fiorello on February 10, 2011, 03:08:56 pm
Hi Jacob!

Can you give us something to compare this list to, like what was suggested by other designers?

Also, did you specify what type of equipment was used or did each designer choose equipment based on their measurements of the space?


Thanks!


JF
Title: Re: Quality of Components?
Post by: Tom Young on February 10, 2011, 04:37:59 pm
I am trying to persuade our church to do a PA overhaul so I have went out and gotten several quotes and the last one I got was almost 40% less than the others.  My question is what your opinion of the components that were chosen and the quality of the system as it might work together as a whole.  I know without more details about the acoustics of the church you cannot give too much feedback, but my question is more about the quality of products chosen.

I'm curious about the services offered by the competing contractors.

Do any of them base their designs on room modeling and/or did any of them conduct a site visit and attend a service or two ?

Do they provide measurement and optimization as part of their installation and commissioning ?

How about sound checks, training and follow up hand-holding ?
Title: Re: Quality of Components?
Post by: Jacob Robinson on February 10, 2011, 10:23:34 pm
Here are the other two competing quotes, it seems that they are all offering very different products with estimates from $11,000 to 23,000

Phase I
OPTION 1
 $5189.93 – 10% church discount = $4670.94
MACKIE ONYX 32.4
FURMAN PS-8R II
ALTO MAXIDRIVE 3.4
BELDEN MIC CABLE
MIDDLE ATLANTIC WALL PLATE / RACK
NEUTRIK CONNECTORS
LABOR

OPTION 2
$5809.94 – 10% church discount = $5228.95
ALLEN & HEATH GL2400 32
FURMAN PS-PRO II
DRIVERACK 260
BELDEN MIC CABLE
MIDDLE ATLANTIC WALL PLATE
NEUTRIK CONNECTORS
LABOR

Phase II
OPTION 1
 $3072.00 – 10% church discount = $2764.80
Personal Monitoring System
Hear Technologies System with 4 Mixers
2 Yorkville YX15P floor Wedges for Singers
Stands for Mixers
Cat 5 Cabling
Connectors
6 25’ Mic Cables
4 15’ Mic Cables
2 10’ Mic Cables
4 20’ Inst Cables
2 10’ Inst Cables
Labor

OPTION 2
$4894.00 – 10% church discount = $4404.60
Personal Monitoring System
Aviom System with 4 Mixers
2 Yorkville YX15P floor Wedges for Singers
Stands for Mixers
Cat 5 Cabling
Connectors
6 20’ Mic Cables
4 15’ Mic Cables
2 10’ Mic Cables
4 20’ Inst Cables
2 10’ Inst Cables
Labor
If only floor wedges are to be used a minimum of 4 YX15P’s are needed along with an ART
Headphone Amp $1700.00 – 10% church discount = $1530.00
I would also recommend the floor boxes be installed to reduce breakage of cat lines across
the platform if personal listening system is used see phase V pricing

Phase III
OPTION 1
$2474.98 – 10% church discount = $2227.49
AUDIX D6 KICK MIC
KICK MIC STAND
WALL TREATMENT BEHIND DRUMS
2 AT 3000 HANDHELD MICS
1 GALAXY HEADSET FOR PASTOR(TO BE USED WITH EXISTING BODY PACK)
1 HEADSET MIC FOR KEYS VOCAL
4 HOSA OR EQUIVALENT DI’S
LABOR

OPTION 2
 $3003.99 – 10% church discount = $2703.60
AUDIX DP7 MIC KIT
ALL OTHER EQUIPMENT THE SAME
LABOR

Phase IV
OPTION 1
$4778.00 – 10% church discount = $4300.20
2 YORKVILLE NX750P SPEAKERS (FLOWN)
2 YORKVILLE NX720S SUBS (SET ON PLATFORM)
FLYWARE
RELAYS
CONNECTORS
LABOR

OPTION 2
$5558.00 – 10% church discount = 5002.20
2 QSC K SERIES TECHNOLOGY SPEAKERS
2 QSC K SERIES TECHNOLOGY SUBS
FLYWARE
RELAYS
CONNECTORS
LABOR

Phase V
OPTION 1
 $3683.90 – 10% church discount = $3315.51
8 Mystery Floor Boxes
2 Speakers for Perimeter w Volume Controls
70v Amp
Labor


OPTION 2
 $3953.90 – 10% church discount = $3558.51
8 Mystery Floor Boxes with Power
3 Speakers for Perimeter w Volume Controls
70v Amp
Labor

OPTION 1: $1869.87       OPTION 2: $2321.97
Title: Re: Quality of Components?
Post by: Brad Weber on February 11, 2011, 07:39:59 am
Tom beat me to it, but how they came up with the equipment listed and what they plan to offer beyond the equipment (testing and adjustments, training, documentation, system warranty, etc.) is part of the value represented by a bid.

The other aspect I often encounter is what the bidders were provided as input or direction.  It's interesting to talk to the bidders on a project and ask their impression of what is wanted, you can find that sometimes you'd think they're talking about totally different projects.  What happens is that the different bidders, depending on who they talk to and when, can get significantly different impressions of what is desired.  To get more of an 'apples-to-apples' comparison, it usually helps to do what you can to make sure that all bidders are working from the same information.  It also helps anyone reviewing the bids to have that same information.

That seems to potentially be a factor here.  I get the impression the list you noted with two options for each phase is actually from one bidder and I'm not sure what the phases represent since that does not seem to be reflected in the other bids.  However, I'm seeing is things like one bid with apprarently no wireless mics, one bid with two wireless mics and two lower cost headset mics and one bid with eight wireless mics including two Countryman E6s.  Some bids with speakers and amps and some with powered speakers, the latter of which seems to include no speaker processing and which would require power that you may have to provide at additional cost.  A CD recorder/player in one bid that does not appear in the others.  One bidder that addresse stage boxes when the others do not appear to.  And so on.  There seem to be a number of fairly significant differences but which is most 'right' or most responsive is impossible to assess without knowing the basis of the bids and what you want.

I've had several churches hire me to help them review the bids they received when situations like this arose.  I had one church where the bids included a simple equipment list and total price from one bidder and a complete and very thorough bid package from another with information on the proposed process, work schedule, payments schedule, qualifications, warranty, system concept and even predicted system performance.  The difference in price was not that great but as in probably the majority of these situations it turned out that what was really being asked was not which bid was the best value but rather could the low bid be absolutely ruled out or not.  Which are you really asking?
Title: Re: Quality of Components?
Post by: Jacob Robinson on February 11, 2011, 05:58:48 pm
Here is basically the story of how this process has went so far. . .In December of 09 I talked with the board of our church about getting a new PA system and they told me to get some bids, so I started in the yellow pages and scheduled a meeting with Sound Force the designer pushed wireless mics to clean up the stage area from cords and was using the Bose Speakers as mains and monitors simultaneously (I have never seen this type of design which made me skeptical)  approx $18,500


Then six months later I was given the name of the person who I met with and suggested the phases so that the budget could be swallowed a little easier.  I am not totally for "phases" because if some in the congregation are wondering why we need new equipment they may never notice much of a change in quality if it is introduced gradually over time.  This estimate seemed to be more involved from an installation standpoint with all of the floor boxes (those would be added when stage carpet is replaced) He also suggested personal monitoring system to keep stage volume down (but i am not sure how the band and vocalists will adapt to PMS and how to use them)  aprox $23,000+


Then about 3 months ago a gentle called me out of the blue and said he had heard that we were looking for a new PA and went on to tell me that he had an PhD in Acoustic Research (not sure if that was a salespitch or not, but I have seen some of his work in very large churches who seemed very pleased with their end product) He is the one who suggested putting the two DAS 28's in (I liked that idea because of their lower profile when flown horizontally)


With all three quotes training and and full installation was included beyond that they had a very vague ideas to work because I didn't want to restrict the system that could be designed.  I just basically told all three that we have a very contemporary worship band and that we wanted a 32 channel mixer and stay around 10 - 15 grand...I realize that all three quotes are very different, which makes it very hard to compare apples to apples.

I would love to do the install myself and save the church, but I have no experience in the design or initial setup portion of a complete overhaul like this. . . Does anybody have anyone have any suggestions of how we should progress from here?

I understand this is a difficult question to ask people who have never visited our church, but I appreciate any and all responses. 




Below I posted a picture of our current dinosaur of a mixer a Peavey MS 1621
Title: Re: Quality of Components?
Post by: Frank DeWitt on February 11, 2011, 07:35:39 pm
There has been some real good input here. especially Tom's questions.

Let me add, what are you trying to fix?  Are there parts of the room that can't hear, or cant understand the spoken word?  Is the stage volume to loud?  Is the mix bad? do you need more channels? 

Answers to these questions could have a big effect on what get's done, or on what get's done first.  For instance, lets say that spoken word sounds great, A CD sounds great, but there is way to much stage volume.  Then step one might be in ear monitors.  The IEMs might drive getting a new snake, and a new board,

OR

If a CD sounds bad, and a lot worse over here then right there, then maybe you need acoustic treatments or new speakers.

Frank

Title: Re: Quality of Components?
Post by: Jacob Robinson on February 11, 2011, 08:27:37 pm
Problems we currently have:

Only 2 monitor mixes
Two few channels; 16 inputs, but only 13 work
Outdated and low quality speakers produce lots of volume, but little clarity
Amps that choose when they want to work, you never know when one will cut out or it might work to perfection. 

all major components are 20+ yrs old, mics and CD recorder are new though
Title: Re: Quality of Components?
Post by: Frank DeWitt on February 12, 2011, 10:39:27 am
Problems we currently have:

Only 2 monitor mixes
Two few channels; 16 inputs, but only 13 work
Outdated and low quality speakers produce lots of volume, but little clarity
Amps that choose when they want to work, you never know when one will cut out or it might work to perfection. 

all major components are 20+ yrs old, mics and CD recorder are new though

OK with this info, you have a place to start.  But first, why am I going off in this direction.

You don't have a specification, therefor your quotes are all over.  That would be OK if you had one person you really trust, but you don't seem to have that either.

The first part is not to hard.  You want more monitor mixes and more auxes, so you need a new board and a new snake (To use with or instead of the old one.)

On the board you need to decide if you want to go analog or digital, and high end or low end.  You can get opinions on this forum or the lab lounge forum on boards.  There have been some good threads lately.

The speakers are much more difficult. They could lack clarity because they always did, or because one driver is blown, or because they are in the wrong place in the room, or because the room needs work.   I would start with these speakers and use this as a way to get some good sound fast, and a way to get to know an expert.

If there is one of the vendors you are leaning towards, you could ask them to rent you speakers (and amps) for one Sunday as a demo.  This would show you a few things. (assuming it results in good sound)  1 It's not the room. 2 The guy knows how to chose speakers.

If there isn't a vendor who will do this or you don't feel comfortable with this route then you really need to find an expert.  You can ask on this list (give your location) and on ChurchSoundCheck.com and see who you can find.

An expert will do the things Tom asked about.  They will base their designs on room modeling,  They will conduct a site visit and possibly attend a service or two.
They will provide measurement and optimization as part of their installation and commissioning. (Paraphrased from Tom)

Your quotes show 4 to 5K on speakers.  If you get them wrong, you need to start over.  I would start with the speakers (and amps) because you need them the most, but I would find and use an expert.

BTW  Amps usually work or they fail.  If they are going in and out, I suspect the speakers, or wiring.

Frank




Title: Re: Quality of Components?
Post by: Jacob Robinson on February 12, 2011, 11:56:07 am
I would love to find someone who I can trust.   Should i post my location in this thread, open a new topic, or a new topic and under a different section?


We are a smaller church in:

Germantown, OH (40 miles north of Cincinnati and 15 miles south of Dayton)
I am looking to get advice/a contractor to completely overhaul our PA $10,000 would be a target budget, but I do realize that that may not be feasible.

Thanks again,
Jake
Title: Re: Quality of Components?
Post by: Frank DeWitt on February 12, 2011, 03:13:54 pm
Perhaps the moderator will jump in on a new thread.  "Looking for a consultant" is difference then Quality of components.  Also, you may want to join Church sound check  http://www.churchsoundcheck.com/list.html just to get some more exposure.

Between Cincinnati and Dayton I bet there are some good Christian professionals and some satisfied customers who know they are good.  I am over in central NY so my contacts won't help.

Frank
Title: Re: Quality of Components?
Post by: chuck clark on February 14, 2011, 09:20:39 pm
Hi Jacb. The first system you list is pretty cool, with the following caveats.
The bag end woofers are a bit shy on max output capability. A general rule of thumb is if your going to put live kick through it, you'll want 15's.  2 10's is lovely for bass guitar but think "physics". If your total cone area is less than a kick drum head, how is it going to "re-inforce" kick drum?  Good luck.
The monitors don't have subs so you'll probly want at least a 10" there. (again, it can get ugly when you put kick thru an 8". Oh the humanity!)
Make the amps 2000's so you have a little overhead. 1000's tend to run out of gas a couple blocks from the gas station if you know what I mean, heh.
Chuck
Oh, a driverack is dandy for this system. I don't think you need the 260, your not tri-amping, so save some money there.
Title: Re: Quality of Components?
Post by: Matthias Heitzer on February 15, 2011, 06:04:02 am
Crown XTIs have their own dsp, so there is no real need for a driverack.
On the other hand, you could use normal amplifiers and a simple 2 way dsp controller.
Just do a bit of math and find out what's cheaper.

I've never seen nor heard that bagend woofer, but it seems to be made for other applications than a church. the bagend homepage list it under home/hifi speakers.

The already low sensitivity of 92db/1W/1m is at 80Hz, it is a small sealed woofer that reminds me of URPS (under resonance principle subwoofer, or something like that, i hate those abbreviations)

That means: below its resonace frequency, every CB has a steep but even roll-off. The cabinet is so small, that the resonance frequency is (or is above) the highest tone the sub is designed to reproduce. Now we take an EQ and create a filter that looks just the opposite of the frequencyresponse of the cabinet. Amp power is cheap and modern speakers can handle huge power.
That's an easy way to get a smooth sub response, but the cost is a ridiculously low sensitivity.
I know there are some people who implement this principle in live reinforcement systems, but then we talk about stacks of 32 or 64  10" or 12" drivers
Title: Re: Quality of Components?
Post by: Brad Weber on February 15, 2011, 08:22:06 am
I think the last couple of posts from Chuck and Matthias maybe unintentionally hit on an issue that hadn't been addressed.  If you go to a design/build firm they are going to put togther a system for you based on the equipment they sell.  They may spend time with you establishing your goals or they may feel they already know what you need.  They may be proposing a very good solution intended to serve you well or they may be proposing what they want to sell you.  However, they will be proposing whatever a solution and they may or may not be open to your wanting to change the design concept or specific products.  The reasons behind that may be that they don't sell the products involved or feel comfortable with anything new.  Or it may be because they have carefully thought everything through and put together what they really believe is the best possible solution.

The difference with a Consultant is that in theory they have no limitations in terms of products and have no financial interest in applying specific products.  It's not that they necessarily know more or don't have product preferences, it's supposed to be that their only interest is supporting you without influence from dealer agreements, potential product sales, profit margins on products, etc.  The tradeoff is that because these services are not related to product sales or the resulting profit, they have to be compensated for directly.  Quite frankly, the detailed design effort noted, such as computer modeling,  is often impractical with smaller budgets.

What you may want to do is to ask the vendors how the equipment translates into results.  I've run into very few churches for which the equipment used is the goal, they are usually thinking more in terms of functionality and performance.  So what are you getting for your money not in terms of an equipment list but rather in terms of the actual system performance and capabilities?  This is also another way I've worked as a Consultant with churches, not developing a full design but rather helping develop a package defining their overall goals and expectations, and also defining expectations such as testing, training, earranty, documentation and so on, that can then be provided to design/build companies and their responses assessed in terms of price and how well the proposed solutions appear to comply with the goals defined.  But if you are comfortable doing so that is something that can potentially be done in-house without any assistance.

As far as specifics, the first system you noted is definitely a compact system with dual 8" woofer mains, dual 10" subs, 8" woofer monitors, etc.  The Bag End DS10E-I is part of Bag End's pro series, although probably at the bottom of that series.  It does indeed operate under resonance, so the physics are a bit different.  And with the ELF Integrator it can provide broad, very low frequency response, they are actually quite amazing in terms of the low frequency response possible from a small box.  However, that extended low frequency response is typically achieved at the expense of output.  So while I would not generalize performance based solely on the size of the drivers as there are many other potential factors, the products listed for that system are going to relate to less system output and thus less level at the listeners.  I have to admit that I don't understand the DriveRack PA+ when the XTi amps have pretty much the same processing integrated into them.

I also agree with Frank's comment regarding focusing on the speaker system.  Speaker systems are usually one of the more difficult aspects of a sound system to get right as well as one of the more expensive and difficult to change, a combination that makes you want to get it right the first time.  Having a good speaker system is also more likely to let you immediately notice any other improvements to the system.

Title: Re: Quality of Components?
Post by: chuck clark on February 16, 2011, 10:02:43 pm
Gee, I knew the XTi amps had a crossover in them but the driverack has input compression, pink noise, pink noise measurement mic input, 3 way stereo crossover, output limiters, dual 1/3 octave eq, parametric eq and a lot of well known spkr. presets. What's in that XTi DSP these days? (I use powerlight amps and always look for infrasonic filtering and input clipping eliminaters on any amp I recommend)
Title: Re: Quality of Components?
Post by: Brad Weber on February 17, 2011, 07:40:00 am
Gee, I knew the XTi amps had a crossover in them but the driverack has input compression, pink noise, pink noise measurement mic input, 3 way stereo crossover, output limiters, dual 1/3 octave eq, parametric eq and a lot of well known spkr. presets. What's in that XTi DSP these days? (I use powerlight amps and always look for infrasonic filtering and input clipping eliminaters on any amp I recommend)
Keep in mind that Crown and dbx are both part of Harman, so guess where the XTi's DSP likely comes from?  It seems to make sense to use what you can from an existing Harman product, so I'll bet that the processing in the Crown XTi is based on the processing in products like the dbx PA+.

The XTi processing includes a stereo/parallel/summed mono mode selection, then for each channel there are six parametric filters, high and low pass filters with choice of Butterworth or L-R and slope, digital bandpass gain, limiter, delay (up to 50ms total), polarity and finally a digital attenuator.  And there are presets.  So while you don't have the compression, subharmonic synthesizer, AFS filters, graphic EQ or measurement function of the PA+, I personally would rarely use those functions in a system processor and the XTi probably provides all the processing needed for most typical applications of these products.

On more complex projects I often use dedicated speaker/array DSP processing and an overall system processor, the latter being user accessible for graphic EQ, different routing presets, etc. while the speaker/array processing remain untouched once set.

Another thing to consider in this particular application is that you have two channels of mains/subs and two channels of monitors, but the dbx PA+ has only two input channels.  So either the PA+ is assigned just to monitors or you are relying on just the processing in the monitor amp for the monitor processing, which for an installed system seems to be the processing one most likely needs to change on any regular basis.
Title: Re: Quality of Components?
Post by: Arnold B. Krueger on February 17, 2011, 07:55:53 am
Gee, I knew the XTi amps had a crossover in them but the driverack has input compression, pink noise, pink noise measurement mic input, 3 way stereo crossover, output limiters, dual 1/3 octave eq, parametric eq and a lot of well known spkr. presets. What's in that XTi DSP these days? (I use powerlight amps and always look for infrasonic filtering and input clipping eliminaters on any amp I recommend)

I guess google is broken on your computer, because the easy-to-find  XTi datasheet says that the XTi DSP provides:

"crossover,  EQ, limiting, delay, and a subharmonic synthesizer"
Title: Re: Quality of Components?
Post by: Michael Galica on February 17, 2011, 10:56:10 am
Hi Jacb. The first system you list is pretty cool, with the following caveats.
The bag end woofers are a bit shy on max output capability. A general rule of thumb is if your going to put live kick through it, you'll want 15's.  2 10's is lovely for bass guitar but think "physics". If your total cone area is less than a kick drum head, how is it going to "re-inforce" kick drum?  Good luck.

Umm, can you throw some math to back that up?  I've done just fine with a single 18" Mackie powered sub "reinforcing" a 22" kick drum.  Ditto with a single LA400, and that's a 12" driver.
Title: Re: Quality of Components?
Post by: Matthias Heitzer on February 18, 2011, 05:37:26 am
Pressure is force per area (thats were psi comes from), so you simply need more force if the area is smaller.
Since the air is a giant spring that affects both the drum and the subwoofer we can also look at the cone (head) traveldistance.

Bassdrums are partially comparable with dipole subs, there is an acoustic short circuit between the two heads (dependent on the tuning) that eats up parts of the emitted energy.

So don't worry to much about cone area, two 10" speakers have a similiar cone area as a 15", the only problem i see ist the low sensitivity of this 2x10" woofer.
Title: Re: Quality of Components?
Post by: Michael Galica on February 18, 2011, 09:50:52 am
Pressure is force per area (thats were psi comes from), so you simply need more force if the area is smaller.

Yes, that's what I was getting at.  When I read Clark's post it seemed he was leaving out the force component behind it.
Title: Re: Quality of Components?
Post by: Brad Weber on February 18, 2011, 10:02:48 am
A general rule of thumb is if your going to put live kick through it, you'll want 15's.  2 10's is lovely for bass guitar but think "physics". If your total cone area is less than a kick drum head, how is it going to "re-inforce" kick drum?  Good luck.
The monitors don't have subs so you'll probly want at least a 10" there. (again, it can get ugly when you put kick thru an 8". Oh the humanity!)
Directly equating the radiator surface areas might be more valid if one were also using the same kick drum and beater for the subwoofer, but you're probably not meaning that the physics involved is much more complex with multiple factors involved.  It's also not just the 'force' or energy of the driver but could also be things such as how effectively that mechanical energy is converted to acoustical energy.  That's why it is not viable to make absolute statements based solely on cone diameter.

Perhaps a bit ironically, years ago Bag End took a typical 8" ceiling speaker, mounted it in a standard shallow backcan and sealed it very well so that the assembly had a higher natural resonance frequency.  Then they ran it with a custom integrator.  As I recall, the resulting frequency response was almost flat down to below 20Hz but the output was extremely low.  They weren't trying to create a viable product but rather demonstrating their concept and the type of compromises and decisions that speaker designers often have to make or for which they must develop creative solutions.
Title: Re: Quality of Components?
Post by: John Fiorello on February 18, 2011, 02:48:40 pm
If you want to send me a PM, I'm about an hour north of you and I'd be glad to let you know who we are using for what with our current upgrades.


JF
Title: Re: Quality of Components?
Post by: Brian Ehlers on February 18, 2011, 05:23:25 pm
Perhaps a bit ironically, years ago Bag End took a typical 8" ceiling speaker, mounted it in a standard shallow backcan and sealed it very well so that the assembly had a higher natural resonance frequency.  Then they ran it with a custom integrator.  As I recall, the resulting frequency response was almost flat down to below 20Hz but the output was extremely low. 
And therein lies the problem with trying to make a loudspeaker do something it's not good at (such as producing frequencies below resonance).  It may work well under some circumstances (low power), but not under others.

My home loudspeakers used to be a full-size model of sealed-box design which used a manufacturer-provided line-level EQ to achieve flat response down to 20 Hz.  And it was flat, as I proved with measurements.  Sounded great, too -- as long as I didn't turn it up too loud.  Problem was, the EQ's 12 dB of boost at 20 Hz made the power amplifier quickly run out of headroom.  And even if a more powerful amp was used, the woofer quickly ran out of excursion room.  To top it off, with a first-order passive crossover design such as this, that 12 dB of boost meant that the midrange driver actually saw a level of 20Hz as if it weren't even high-passed.  You can guess which driver failed first.

Anyway, while having some potential in low-power applications, I'm not a fan of such "interesting" designs for Pro audio.
Title: Re: Quality of Components?
Post by: Arnold B. Krueger on February 22, 2011, 07:58:41 am
My home loudspeakers used to be a full-size model of sealed-box design which used a manufacturer-provided line-level EQ to achieve flat response down to 20 Hz.  And it was flat, as I proved with measurements.  Sounded great, too -- as long as I didn't turn it up too loud.  Problem was, the EQ's 12 dB of boost at 20 Hz made the power amplifier quickly run out of headroom.  And even if a more powerful amp was used, the woofer quickly ran out of excursion room.  To top it off, with a first-order passive crossover design such as this, that 12 dB of boost meant that the midrange driver actually saw a level of 20Hz as if it weren't even high-passed.  You can guess which driver failed first.

The above is an example of how to do it wrong. I can tell you how to do it right, with examples. I have a friend who is a well-known speaker designer - he's an AES Fellow of which there are precious few. He figured out the desired  parameters for a high-powered, high excursion driver that would work well in a minimial-sized box, and proceeded to house two of them back-to-back in an enclosure that was just barely big enough to hold the drivers. This resulted in a system that naturally rolled-off some place around 50 Hz.

He then lined up some amps that were so powerful that he had to run a 230 volt line dedicated to them, but were within the power ratings  of the speakers and drove them  to displacments that were clearly within their design limits.

A parametric eq was used to equalize response to 10 Hz, which required fairly massive amounts of eq. This system has been in daily use, driven hard from time to time, and has been reliable for a number of years. It sounds great. BTW, the upper range drivers were themselves nomiinally full range speakers and were used within specs.

My point is that if you know what you are doing and can apply proper engineering princlples , that this like many other seemingly radical approaches can work very well.  I had a 14 cubic foot subwoofer in my listening room for over a decade, and can thus appreciate the attraction of physically small speakers that haul the mail.