SHOOTOUT! Epik Empire vs HSU VTF-15H vs CHT CS18.1 vs Rythmik FV15 vs eD A7s-450 - Page 28 - AVS Forum
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post #811 of 1241 Old 03-10-2011, 07:43 AM
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Back on topic or you'll be removed and/or we'll shut down the thread.

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post #812 of 1241 Old 03-10-2011, 07:44 AM
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Is EVERY sub and driver for that matter going to follow WINISD or whatever modeling program every time?

Wouldn't we rather look at real life measurements? If people aren't exactly sure of WHAT driver it is, can modeling just based on box size and driver size and power, etc be right?

I really don't know, just asking.
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post #813 of 1241 Old 03-10-2011, 07:57 AM
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Back on topic or you'll be removed and/or we'll shut down the thread.

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what he said

Let me add that this thread is not for discussions about what goes on at another site:

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post #814 of 1241 Old 03-10-2011, 08:27 AM
 
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I've found pro reviews for the Hsu, the Rythmik, and the eD subs, but all I can find on the Epik is a Cnet blurb. Is there a real pro review available for the Empire yet?
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post #815 of 1241 Old 03-11-2011, 08:50 AM
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Here is the close mic graph I promised. Bass boost off, EQ defeated, no filters. My subs are in a corner and might be why I am getting that 40hz hump.

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post #816 of 1241 Old 03-11-2011, 09:12 AM
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Quote:
Originally Posted by MKtheater View Post

Here is the close mic graph I promised. Bass boost off, EQ defeated, no filters. My subs are in a corner and might be why I am getting that 40hz hump.


I'm certainly no expert, but your close mic and Craig's close mic look very similar to me.

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post #817 of 1241 Old 03-11-2011, 09:24 AM
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PLEASE READ:

Hi guys, as you've noticed (quicker than I thought) the mods were kind enough to unlock the thread. I am asking we leave the conversation from the past few pages where it is and move on.

If you own one of these subs and would like to contribute to the conversation by adding some insight into ownership for potential buyers, please feel free. If you are a potential buyer and have questions about how the subs compare not answered in the shootout, please feel free to post. There's plenty of owners besides ourselves that can answer your questions. We also encourage potential buyers to post in the official owner's threads and the forums on the ID company's websites.

Thanks guys,
below90hz and madaeel
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post #818 of 1241 Old 03-11-2011, 09:39 AM
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Quote:
Originally Posted by below90hz View Post

PLEASE READ:

Hi guys, as you've noticed (quicker than I thought) the mods were kind enough to unlock the thread. I am asking we leave the conversation from the past few pages where it is and move on.

If you own one of these subs and would like to contribute to the conversation by adding some insight into ownership for potential buyers, please feel free. If you are a potential buyer and have questions about how the subs compare not answered in the shootout, please feel free to post. There's plenty of owners besides ourselves that can answer your questions. We also encourage potential buyers to post in the official owner's threads and the forums on the ID company's websites.

Thanks guys,
below90hz and madaeel
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Good deal. I was worried that once locked, this thread would sink like Atlantis and the huge amount of work you guys put in here would not be seen by most casual posters and lurkers looking into ID subs.

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Holy smokes. A simple question turned into a buck wild display of thoughts, gazillion graphs, multiple interpretations, philosophies, and overall mayhem!!
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post #819 of 1241 Old 03-11-2011, 10:38 AM
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Thankfully it is reopened. After all the work you and your brother did it would have been a shame. Madaeel was very resourceful in helping me choose the HSU and I am really happy with my purchase.

Now if I could only get more insight into heights vs wides for my front setup I would be even a happier camper.

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PLEASE READ:

Hi guys, as you've noticed (quicker than I thought) the mods were kind enough to unlock the thread. I am asking we leave the conversation from the past few pages where it is and move on.

If you own one of these subs and would like to contribute to the conversation by adding some insight into ownership for potential buyers, please feel free. If you are a potential buyer and have questions about how the subs compare not answered in the shootout, please feel free to post. There's plenty of owners besides ourselves that can answer your questions. We also encourage potential buyers to post in the official owner's threads and the forums on the ID company's websites.

Thanks guys,
below90hz and madaeel
Ethan_________Adam
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post #820 of 1241 Old 03-11-2011, 10:50 AM
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Quote:
Originally Posted by MKtheater View Post
Here is the close mic graph I promised. Bass boost off, EQ defeated, no filters. My subs are in a corner and might be why I am getting that 40hz hump.

If I am reading all of the close mic graphs correct so far, here is what I see. I think both MKtheater and Lilgator used the RS SPL meter but don't know what compensation was used. Craig used a calibrated TEF mic.

MKtheater, ignoring the 40hz bump, baseline at 50hz, flat above 50hz
40hz: -1db
30hz: -2db
20hz: -4db
10hz: -23db

LilGator, baseline at 50hz, rising response between 50-90hz
40hz: -3db
30hz: -6db
20hz: -12db
10hz: -19db

Craigsub, baseline at 50hz.
40hz: -1db
30hz: -7db
20hz: -14db
10hz: -30db (this is a guess since 10hz was off cutoff)

My thoughts are some of the differences are caused by the mics, some because of the rooms and probably other reasons I don't know about.

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post #821 of 1241 Old 03-11-2011, 10:52 AM
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Maybe someone should start a "CS18.0 close-mic measurement discussion" thread or something along those lines given it wouldn't be "fair" to the OPs if their thread was locked due to discussion on the CS...

Admittedly, I don't recall this thread ever actually being locked, only that the mods said it would be if the discussion was way off topic.

 

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post #822 of 1241 Old 03-11-2011, 06:45 PM
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Quote:
Originally Posted by Gooddoc View Post

I'm certainly no expert, but your close mic and Craig's close mic look very similar to me.

Quote:
Originally Posted by pbc View Post

Maybe someone should start a "CS18.0 close-mic measurement discussion" thread or something along those lines given it wouldn't be "fair" to the OPs if their thread was locked due to discussion on the CS...

Admittedly, I don't recall this thread ever actually being locked, only that the mods said it would be if the discussion was way off topic.

Quote:
Originally Posted by tesseract67 View Post

There is a thread about this at the CHT forum.

Glad to see this thread back. Ethan and Adam, moving forward >>>

I would also like to see the close mic measurements and perhaps those that are posting on other forums can find the time to share their measurements here.

With respect to what you said, Gooddoc, about MK's close mic measurement looking similar to that of Craig's, I'll have to strongly disagree. As I look at the data with my detective in chief hat on, there are fundamental differences such that one set of data supports the behavior of a sealed sub while the other doesn't.

MK's measurements essentially confirm the presence of a sealed sub. If you look at the slope of the line you'll see it's pretty close to that of 12db/octave. An octave is a doubling of frequency 10-20 Hz, 12-24 Hz. You can calculate the slope by picking two points on the X axis where one is double the other and then reading the equivalent response on the Y axis. Subtracting the two Y axis values then tells you the slope. All sealed subs that don't have additional circuitry or filters will behave this way.

MK's also show an inductance hump.

However, when we examine the close mic graph that CHT provides and do the same sort of calculation, we find that the slope is about 18dB/octave.
  • 1st order - 6dB/octave
  • 2nd order - 12 dB/octave
  • 3rd order - 18 dB/octave
  • 4th order - 24 dB/octave
So, the question to my mind is, why does CHT's graph bear no resemblance whatsoever to a sealed sub whose slope is mandated by its design to be 12dB/octave?

Now, I have seen some meaurement graphs of subs that have exhibited a quasi-3rd order response but those have been of certain servo based units which have applied electronic equalization.

I am searching for explanations why CHT's close mic measurements not only don't reflect what users are getting but are not consistent with the predicted behavior of a sealed sub? If one of their products was in fact measured, then a possible explanation is that the extra 6dB of slope came from the addition of a 1st order filter, electronic or otherwise, along with some non-trivial electronic enhancements. CHT has been involved with subs, whether as a serious hobby and business enterprise long enough to recognize the data presented is most certainly not kosher.

Providing room responses can be informative. Bringing in other sub drivers or products from different manufacturers or DIY builds can be fun. But both of these excercises serve to divert attention from CHT's close mic measurements of one of their products. Having personal testimonials and addressing owner satisfaction or not is also informative but they too divert attention.

IMO, this dilemna is easily resolvable by CHT. Replicate the measurements. This could be done by Craig, and if memory serves me right, Edge, the CHT representative, is also capable of performing such measurements. AFAIK, they're not especially difficult or time consuming. So, what say you folks?

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post #823 of 1241 Old 03-11-2011, 08:25 PM
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Quote:
Originally Posted by Chu Gai View Post

MK's measurements essentially confirm the presence of a sealed sub. If you look at the slope of the line you'll see it's pretty close to that of 12db/octave. An octave is a doubling of frequency 10-20 Hz, 12-24 Hz. You can calculate the slope by picking two points on the X axis where one is double the other and then reading the equivalent response on the Y axis. Subtracting the two Y axis values then tells you the slope. All sealed subs that don't have additional circuitry or filters will behave this way.

MK's also show an inductance hump.

However, when we examine the close mic graph that CHT provides and do the same sort of calculation, we find that the slope is about 18dB/octave.
  • 1st order - 6dB/octave
  • 2nd order - 12 dB/octave
  • 3rd order - 18 dB/octave
  • 4th order - 24 dB/octave
So, the question to my mind is, why does CHT's graph bear no resemblance whatsoever to a sealed sub whose slope is mandated by its design to be 12dB/octave?

Thanks Chu. However, when I read MK's graph above I see exactly 18 dB from 20Hz-10Hz, not 12 dB. Why is that?

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post #824 of 1241 Old 03-12-2011, 12:38 PM
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Originally Posted by Gooddoc View Post

Thanks Chu. However, when I read MK's graph above I see exactly 18 dB from 20Hz-10Hz, not 12 dB. Why is that?

I agree, MK's graph from 10-20hz does have roughly an 18db slope.

So, I have a couple of questions (just trying to learn here...):

1. Wouldn't it be more preferable to have a 12db slope as opposed to an 18db slope? Why would an 18db slope be a good thing for a sealed design?

2. Is it theoretically impossible for sealed sub to have anything but a 'natural' 12db slope from a closed mic measurement? Is that the debate?
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post #825 of 1241 Old 03-12-2011, 02:13 PM
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Originally Posted by dominguez1 View Post


So, I have a couple of questions (just trying to learn here...):

1. Wouldn't it be more preferably to have a 12db slope as opposed to an 18db slope? Why would an 18db slope be a good thing for a sealed design?

2. Is it theoretically impossible for sealed sub to have anything but a 'natural' 12db slope from a closed mic measurement? Is that the debate?

1. See 2.

2. Yes, sealed subwoofers are 2nd order. If one is measured and the result is a 3rd order roll off, a manipulation of the signal is in line or the measurement procedure and/or measurement hardware is flawed.

Bosso
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post #826 of 1241 Old 03-12-2011, 02:40 PM
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Quote:
Originally Posted by bossobass View Post

1. See 2.

2. Yes, sealed subwoofers are 2nd order. If one is measured and the result is a 3rd order roll off, a manipulation of the signal is in line or the measurement procedure and/or measurement hardware is flawed.

Bosso

Thanks for your answer...and I understand that sealed subs are 2nd order.

Let me ask this in a different way:

If I were a CHT 18.1 owner and I measured the response closed mic and the resulting graph looked like MK's or CHT's posted graph, I would be concerned that something is wrong. Instead of a 12db slope, it's an 18db slope; meaning I'm not getting the full benefit of the 2nd order rolloff a sealed sub??

Isn't the 18db slope indicated by the graphs a bad thing?
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post #827 of 1241 Old 03-12-2011, 02:54 PM
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Originally Posted by HuskerOmaha View Post

Is EVERY sub and driver for that matter going to follow WINISD or whatever modeling program every time?

Wouldn't we rather look at real life measurements? If people aren't exactly sure of WHAT driver it is, can modeling just based on box size and driver size and power, etc be right?

I really don't know, just asking.

Modeling is more of a design tool. You are right about any design requiring real life measurements but two things need to be done.

1. Accurate measurement equipment is needed. Meaning calibrated mic, etc which is beyond using an RS meter.

2. Elimination of the room. This is the pretty hard for most people to do, close mic still has the room impacting the measurements.

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post #828 of 1241 Old 03-12-2011, 03:17 PM
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Quote:
Originally Posted by dominguez1 View Post

Thanks for your answer...and I understand that sealed subs are 2nd order.

Let me ask this in a different way:

If I were a CHT 18.1 owner and I measured the response closed mic and the resulting graph looked like MK's or CHT's posted graph, I would be concerned that something is wrong. Instead of a 12db slope, it's an 18db slope; meaning I'm not getting the full benefit of the 2nd order rolloff a sealed sub??

Isn't the 18db slope indicated by the graphs a bad thing?

No, any subwoofers final frequency response magnitude is not necessarily a bad thing. If the posted close mic is accurate, it is what it is and good or bad is for the owner to decide.

What would concern me as an owner would be 2 things:

1) The manufacturer's specification reads: Frequency Response: 23Hz – 200Hz +/- 3 dB, and the posted close mic is -3dB @ 36 Hz.

2) If the posted close mic response is in error, why can't the manufacturer post the correct response, and, if the posted close mic is accurate, how did the manufacturer come up with the published frequency response?

Bosso
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post #829 of 1241 Old 03-12-2011, 03:32 PM
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Quote:
Originally Posted by bossobass View Post

No, any subwoofers final frequency response magnitude is not necessarily a bad thing. If the posted close mic is accurate, it is what it is and good or bad is for the owner to decide.

What would concern me as an owner would be 2 things:

1) The manufacturer's specification reads: Frequency Response: 23Hz - 200Hz +/- 3 dB, and the posted close mic is -3dB @ 36 Hz.

2) If the posted close mic response is in error, why can't the manufacturer post the correct response, and, if the posted close mic is accurate, how did the manufacturer come up with the published frequency response?

Bosso

Since the spec is +/- 3db, the -6db point could be 23hz?

Kemper Holt
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post #830 of 1241 Old 03-12-2011, 03:51 PM
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Originally Posted by klh007 View Post

Since the spec is +/- 3db, the -6db point could be 23hz?

If one knows how to read a frequency response magnitude graph, there is no + on the posted graph. It is technically written: (as posted) 36-100 Hz, +0/-3dB.

Some engage in specsmanship by lowering the '0' point by -3dB and incorrectly posting the spec as +/-3dB, allowing the claimed -3dB point to actually be the -6dB point.

Even allowing for that, the posted close mic response has a -6dB point of 31Hz.

Bosso
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post #831 of 1241 Old 03-12-2011, 04:15 PM
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Quote:
Originally Posted by bossobass View Post

No, any subwoofers final frequency response magnitude is not necessarily a bad thing. If the posted close mic is accurate, it is what it is and good or bad is for the owner to decide.

Yes, but it the context of a sealed design, I would think an 18db slope when it supposed to be a 12db slope is a bad (e.g. something is wrong) thing...
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post #832 of 1241 Old 03-12-2011, 04:49 PM
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Originally Posted by dominguez1 View Post

Yes, but it the context of a sealed design, I would think an 18db slope when it supposed to be a 12db slope is a bad (e.g. something is wrong) thing...

Nah, that's the thing it really isn't important at all, once you put it in a room all bets are off. I think that's part of why Bosso's a bit defensive having been attacked for making an observation on something that's really not important
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post #833 of 1241 Old 03-12-2011, 08:30 PM
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Here is my natural, no dcx, no audyssey, no eq, close mic.

Using a Tascam US122, ECM 8000 calibrated.

Pictures of equipment used.

Picture of final position after EQ today, will post pictures and sequence of REW graphs in my build thread soon.

Pulled the sub out approx feet from wall, on side, holding ECM8000 <1 inch from cap. Other sub was off.

(I'm sure this doesn't look right, I might have time tomorrow to apply better limits and repost it)


EDIT: I think we might have left the bass boost on. We did this close mic after all of the other 5 hours of EQ with the DCX.
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post #834 of 1241 Old 03-12-2011, 08:32 PM
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Originally Posted by lennon_68 View Post

Nah, that's the thing it really isn't important at all, once you put it in a room all bets are off. I think that's part of why Bosso's a bit defensive having been attacked for making an observation on something that's really not important

Correct.

The problem I have with the whole affair is that CHT has posted data about the CS subs that doesn't jive with the actual evidence from this shootout and in the close mic measurements.

Chase has told me (and has posted this elsewhere):

Quote:


The CS-18.2 will have a response curve of +/- 3 dB from 23 to 200 Hz. The response curve is deliberately going to roll off at 12 dB per octave below 23 Hz to match the room gain of the intended room for a subwoofer in its size and price category.

The posted close-mic responses (both MKT's and Chase's reveal neither +/- 3dB from 23 to 200 Hz, nor a 12dB per octave slope.

As I mentioned earlier in the thread, most comments from owners confirm probability of a higher knee and steeper roll off, as does the shootout graphs of the FRs of the subs in the same room with the same sub location for each, showing the highest knee/steepest roll off is that of the CS sub.

For example, the Epik Empire claims a spec of: Frequency response : 20-300 Hz +/-3.5 dB anechoic, yet it was measured by the shootout team as having +15dB higher response at 20 Hz than the CS sub, same placement, same mic position, same calibration.

The published spec should be what the sub actually produces. That's a no-brainer.

Bosso
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post #835 of 1241 Old 03-12-2011, 08:40 PM
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Quote:
Originally Posted by HuskerOmaha View Post

Here is my natural, no dcx, no audyssey, no bass boost, no eq, close mic.

Using a Tascam US122, ECM 8000 calibrated.

Pictures of equipment used.

Picture of final position after EQ today, will post pictures and sequence of REW graphs in my build thread soon.

Pulled the sub out approx feet from wall, on side, holding ECM8000 <1 inch from cap. Other sub was off.

(I'm sure this doesn't look right, I might have time tomorrow to apply better limits and repost it)

Did you leave the sub down-firing and slide the mic underneath, or did you have the driver front-firing and put the mic on axis on a stand?

Thanks for the effort.

Bosso
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post #836 of 1241 Old 03-12-2011, 08:49 PM
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Quote:
Originally Posted by bossobass View Post

Did you leave the sub down-firing and slide the mic underneath, or did you have the driver front-firing and put the mic on axis on a stand?

Thanks for the effort.

Bosso


Driver was front firing. Mic on axis <1 inch from cap.

Like I said in my edit earlier, I believe bass boost was left on.
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post #837 of 1241 Old 03-13-2011, 04:39 PM
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Ethan and Adam,

I just got through the thread, great effort guys. Proceeding throughout the thread, a few things came to mind. First, and most obviously, is how incredibly dominating the room* is in the speaker/room equation. Many AVS contributers post about it frequently, myself included, but rarely is it been more evident than here. I also realize the vast majority of readers of this thread grasp this, however I felt it's so significant here, it was worthy of additional attention. Posters squabble over the minutia of other aspects, and split hairs over this and that, but the heavy hand of the acoustic transfer function trumps all.

Also, having a strong photography background I immediately noticed the lighting used in the production effort was largely superb. It doesn't take experience in this regard to notice this either....it's killer. Just a beautiful, soft, diffuse, large source allowed ideal exposure for highly resolving images. Hats off to you.

*By room, I mean everything...from LP, to PVG, boundary gain, diaphragmatic boundary losses, location of DUT, room appointments, the totality of it all just dominates the LF presentation.

Guys, good stuff. More entertaining threads are certainly welcome. Thank you very much for the effort.





Bosso;
Quote:


Multiplying the amount of drivers doesn't lower extension.

I take exception to this Bosso. I'm not sure this is the proper venue to discuss it fully. It's my understanding, utilizing multiple drivers is a design avenue for added extension.





Chu;
Quote:


Would you perhaps have a close mic'd graph of a sealed sub (underdamped?), either your own or that of somebody else, that you could post to illustrate what one should expect to see?

This is a near-field, naked, and sealed sub. And contained in the same graph, is the same sweep signal and drive voltage level, the only change is the mic location. One at the driver, one at the LP. This illustrates the onset of room gain at approx 23hz or so.

Regardless, the thin red trace is a typical sealed alignment actual measurement, not calculated.







Penn;
Quote:


There never be much objectivity in any forum from small ID companies

Penn, I peruse many forums, I frequent even fewer. That said, I frequent Seaton Sound's forum. Seaton's forum seems to contain a substantially higher level of objectivity than any mfr. forum I can think of. I'm sure there are examples to the contrary, but when you stated any forum, I feel as if I need to stick up for the contributions there. IMO,...It's solid.



Thank you

------------------------------------
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------------------------------------
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post #838 of 1241 Old 03-13-2011, 04:53 PM
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A better graph for how much sub location in my room varied is posted in the CHT thread.

I'll put a little better close mic graph in here.

Bass boost was accidentally left on, but everything else was defeated.
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post #839 of 1241 Old 03-15-2011, 04:11 PM
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Sorry been a few days since I got on here, been super busy. So I'd like to belatedly address a few comments:

Quote:
Originally Posted by pbc View Post

Maybe someone should start a "CS18.0 close-mic measurement discussion" thread or something along those lines given it wouldn't be "fair" to the OPs if their thread was locked due to discussion on the CS...

Admittedly, I don't recall this thread ever actually being locked, only that the mods said it would be if the discussion was way off topic.

Good idea about separate thread. Haven't looked but I guess someone will if they haven't already. Also, the thread was only locked for less than a day so that's probably why you might not have noticed.

Quit readin my signature ya stupid signature reader.
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post #840 of 1241 Old 03-15-2011, 04:12 PM
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Quote:
Originally Posted by Chu Gai View Post

...MK's measurements essentially confirm the presence of a sealed sub. If you look at the slope of the line you'll see it's pretty close to that of 12db/octave. ...

However, when we examine the close mic graph that CHT provides and do the same sort of calculation, we find that the slope is about 18dB/octave.

...So, the question to my mind is, why does CHT's graph bear no resemblance whatsoever to a sealed sub whose slope is mandated by its design to be 12dB/octave?

First off, thank you Chu for posting in a polite, non-accusatory manner. I found your post very informative, so thanks for that too.

My question - which I direct more at Bosso and Penngray since they seem to be making the biggest stink - is why are you accusing Craig of manipulating his FR charts to be worse than real-world measurements like its a bad thing? You do realize getting a product that performs better than what the manufacturer says it does is a GOOD thing right?

Quote:
Originally Posted by dominguez1 View Post

Yes, but it the context of a sealed design, I would think an 18db slope when it supposed to be a 12db slope is a bad (e.g. something is wrong) thing...

Chu Gai's post above seems correct to me, the CS18.X performs better than what Craig posted, not worse. I believe the reason you think its worse is because you are looking at 10-20hz slope, you should be looking at 20-50hz. Even the ported subs drop off pretty quick down to 10hz.

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