DIY 3 way main speaker with 15" drivers?? - Page 7 - AVS Forum
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post #181 of 862 Old 06-27-2008, 11:25 AM
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Quote:
Originally Posted by Looneybomber View Post

Google "Winisd"
Click the first link that pops up.
Eventually you get here -> http://www.linearteam.dk/default.asp...load=winisdpro
Download that.
Read the help file because it'll explain how you put in all the TSP's and in what order because it'll calculate some of the values for you. If a number is off by .001 it'll give you an error message and wont work. It's frustrating at first, but you'll get it down.


I feel bad for that amp.

Cool thanks
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post #182 of 862 Old 06-27-2008, 12:21 PM - Thread Starter
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WinISD etal works for Lambda woofer too.

Yes it does and I have been too lasy to input the numbers just yet.

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post #183 of 862 Old 07-01-2008, 08:02 PM
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For those anxiously waiting, I plan to put test cabinets together tomorrow for 2 different cabinets. One for the dual 12's with 6.5" mid and ribbon tweeter, the other for single 12" with 6.5" mid and the lower cost fountek ribbon. I'll have an interchangeable baffle so I can swap out the two different 6.5" options. Then I'll get some measurements and see where things are at. I want to get distortion measurements, etc but do it with the drivers over the needed operating range with levels matched, etc. And also do some subjective listening as well. I'll post up some cabinet pics, etc soon.

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post #184 of 862 Old 07-01-2008, 09:27 PM
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Hey John, what about those of us that want to use the TD15x? Or am I the only one?

YID DIY
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post #185 of 862 Old 07-01-2008, 10:41 PM
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Should be real similar to the 12x design I would think.

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post #186 of 862 Old 07-01-2008, 10:42 PM
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Sweet John can not wait to see what you think of the different drivers.

Nate

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post #187 of 862 Old 07-02-2008, 04:13 AM - Thread Starter
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John, that is awesome!

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post #188 of 862 Old 07-02-2008, 06:45 AM
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Quote:
Originally Posted by Looneybomber View Post

Hey John, what about those of us that want to use the TD15x? Or am I the only one?

You are not the only one. I plan on 'stimulating the economy' shortly with a pair of the TD15x's.
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post #189 of 862 Old 07-02-2008, 07:47 AM
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Originally Posted by chasw98 View Post

You are not the only one. I plan on 'stimulating the economy' shortly with a pair of the TD15x's.

Nice Are you planning on 3way active, passive, or a mix of both?

YID DIY
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post #190 of 862 Old 07-02-2008, 07:49 AM
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John....I emailed you before the TD12Ms to Singapore. If you have a good 3-way design at a good price i might as well get speakers from ya.

I am looking at the SA cabs....very expensive though, due to the ribbon which is out of this world.
http://www.stageaccompany.com/en/pro...ew.php?psid=13

Read your forum, its the same with the DDS horns. I have it with the Beyma CP380/M driven actively with single ended triode amp (18W SET 6C33CB) and EQed, it sounds really good. In fact I have this on play more often than the Beyma TPL-150 AMT.
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post #191 of 862 Old 07-02-2008, 09:18 AM
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Quote:
Originally Posted by Looneybomber View Post

Nice Are you planning on 3way active, passive, or a mix of both?


I just finished a 3 way active on the low/passive on the mid/hi. With the TD15X woofer having a very good frequency response, I am thinking of all passive, but I will test and design using active to run some "what if" scenario's. Not sure how it will end up.
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post #192 of 862 Old 07-02-2008, 02:02 PM
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Quote:
Originally Posted by chasw98 View Post

I just finished a 3 way active on the low/passive on the mid/hi. With the TD15X woofer having a very good frequency response, I am thinking of all passive, but I will test and design using active to run some "what if" scenario's. Not sure how it will end up.

I think many DIYers haven't taken the time to do accurate model on this. If you are going to cross to the mid above 400-600Hz, it's pretty simple. Crossing lower than that passively gets tricky very fast, especially if your amplifier doesn't like 2 Ohm loads. It is most certainly possible to do, but there's nothing textbook about it.

Active will be the most flexible and the highest confidence solution for most DIYers. This allows you to quickly adjust most any of John's woofer solutions to the mid-high section with just a little more power and some EQ. It would be possible for John to provide a target near field or outdoor response from the woofers to use as a target response for the crossover integration. Having cheap DSP like the DCX available makes these more complex designs much more accessable and easier to implement and modify for different form factors. I'd say don't fight it.

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post #193 of 862 Old 07-02-2008, 03:20 PM
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Quote:
Originally Posted by Mark Seaton View Post

I think many DIYers haven't taken the time to do accurate model on this. If you are going to cross to the mid above 400-600Hz, it's pretty simple. Crossing lower than that passively gets tricky very fast, especially if your amplifier doesn't like 2 Ohm loads. It is most certainly possible to do, but there's nothing textbook about it.

Active will be the most flexible and the highest confidence solution for most DIYers. This allows you to quickly adjust most any of John's woofer solutions to the mid-high section with just a little more power and some EQ. It would be possible for John to provide a target near field or outdoor response from the woofers to use as a target response for the crossover integration. Having cheap DSP like the DCX available makes these more complex designs much more accessable and easier to implement and modify for different form factors. I'd say don't fight it.


Mark:
I agree with you about an accurate model not having been done (or not being publicly available yet). From what I have seen (not heard or measured) these woofers can go to 2K which would mean a target point between 500 and 1K is feasible. I learned on my previous 3 way project that a passive xover on the bottom is not feasible in todays economy. The copper and the losses in the huge inductors needed is not worth the money. You can get an adequate amp and electronic crossover for what you might put into parts for a passive. But a 400 to 800 Hz or so might have possibilities.

If and when I get some TD15's I will definitely post my measurements of the raw driver so that we can at least have a comparison to go by.

Chuck
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post #194 of 862 Old 07-02-2008, 03:34 PM
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Hey chuck, I have heard that with the apollo upgrades, you can cross these over even higher, you would be solely limited by your c-c spacing, I have heard that even first order slopes are possible with fairly high crossover points on these drivers.
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post #195 of 862 Old 07-02-2008, 04:11 PM
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Originally Posted by armystud0911 View Post

Hey chuck, I have heard that with the apollo upgrades, you can cross these over even higher, you would be solely limited by your c-c spacing, I have heard that even first order slopes are possible with fairly high crossover points on these drivers.

See, that is the problem "I have heard" and not "Here is a graph, or I used it and this is the measurement". John is very busy just getting AE running smoothly and keeping his head on straight that having the time to take accurate measurements in not in the cards right now. Now, I believe, that these are superior drivers but I have no real numbers to go on until I get a pair in my hot little hands and measure.
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post #196 of 862 Old 07-03-2008, 07:43 AM
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Quote:
Originally Posted by chasw98 View Post

Mark:
I agree with you about an accurate model not having been done (or not being publicly available yet). From what I have seen (not heard or measured) these woofers can go to 2K which would mean a target point between 500 and 1K is feasible. I learned on my previous 3 way project that a passive xover on the bottom is not feasible in todays economy. The copper and the losses in the huge inductors needed is not worth the money. You can get an adequate amp and electronic crossover for what you might put into parts for a passive. But a 400 to 800 Hz or so might have possibilities.

If and when I get some TD15's I will definitely post my measurements of the raw driver so that we can at least have a comparison to go by.

Chuck

Hi Chuck,

As most know, I prefer to throw "convention" out the window and go with what has scientific basis and agrees with how/what we hear. My point here was more that we are talking about 3 way designs, and while a 2 way passive crossover is a very managable task, many more things interact if you add a high pass on the midrange, and target a lower frequency crossover on a woofer.

The hurdles I'm hinting at are entirely separate from the component values. This is related to the low pass proximity and interaction with the LF corner of the woofer being used. I would say the impedance minimum just below the inductive rise is about the range where things get complicated. Complications are two fold. First you have the matter of getting a smooth response that is close to the target without peaking or other oddities in the response. Secondly, you have to keep the minimum impedance above an acceptable minimum. There are a few brute force means, which will involve lots of big and expensive components, but some departure from common targets in woofer alignment intended to beneficially combine with the passive crossover can make a 12 component solution turn into a 2-4 component solution. In effect this is a bandpass system involving electrical and acoustic filters, not just acoustic like some of the subwoofers I've been designing. Just as with bandpass designs, you can't take either the high or low pass in isolation and expect accurate results.

If you are after easy intergration and smooth on/off axis response, crossovers below 500Hz are required, desireable, and easily accomidated by midranges currently available. Jeff Bagby had noted on HT Guide that his free software would allow you to import the impedance of a measured or modeled woofer to design the crossover around. I suggest that some invest the time to attempt a 2nd, 3rd or 4th order crossover on the woofers they have in mind with the modeled impedance of the alignment they intend.

I have a handful of models for the 10, 12, & 15" TD drivers that will work nicely for very high sensitivty, vented bass alignments which will nicely cross in the 200-350Hz range. Low frequency extension is limited, but that's what subwoofers and kWs of power are for. 96-103dB @ 2.8V @1m is not all that hard, and can be had in anywhere from 60-260L depending on how low you really want to go. Since there is a lot of interest outside of the DIY world, I'm looking at such a configuration to allow a passive variation on my Catalyst, which John's drivers do a nice job of enabling.

Mark Seaton
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post #197 of 862 Old 07-03-2008, 08:13 AM
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How hard would it bet to compose a crossover for a TD15M sealed from 80hz to say 400hz, handing off to a B&C 8PE 21 and lastly to an Altec 902A on a B&C ME10 horn ?
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post #198 of 862 Old 07-03-2008, 09:11 AM
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...... nuke



The storm was gone, but dark clouds still hung around
The perfect setting for things to come......

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post #199 of 862 Old 07-03-2008, 09:15 AM
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Quote:
Originally Posted by gpmbc View Post

How hard would it bet to compose a crossover for a TD15M sealed from 80hz to say 400hz, handing off to a B&C 8PE 21 and lastly to an Altec 902A on a B&C ME10 horn ?

Not too hard if you are ok with a 3-4 Ohm minimum and assuming you have the 400Hz high pass on the B&C figured out.

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post #200 of 862 Old 07-03-2008, 09:39 AM
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The reason I sent a couple mids up to John for listening and some testing for crossover solutions and will be getting them back here shortly for some listening tests of my own. Thanks for all the help thy. And I hope to have some serious speakers for my theater soon.

Nate

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post #201 of 862 Old 07-03-2008, 10:24 AM
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Quote:
Originally Posted by Mark Seaton View Post

The hurdles I'm hinting at are entirely separate from the component values. This is related to the low pass proximity and interaction with the LF corner of the woofer being used. I would say the impedance minimum just below the inductive rise is about the range where things get complicated. Complications are two fold. First you have the matter of getting a smooth response that is close to the target without peaking or other oddities in the response. Secondly, you have to keep the minimum impedance above an acceptable minimum. There are a few brute force means, which will involve lots of big and expensive components, but some departure from common targets in woofer alignment intended to beneficially combine with the passive crossover can make a 12 component solution turn into a 2-4 component solution. In effect this is a bandpass system involving electrical and acoustic filters, not just acoustic like some of the subwoofers I've been designing. Just as with bandpass designs, you can't take either the high or low pass in isolation and expect accurate results.

I am starting to grasp where you are coming from.

Quote:
Originally Posted by Mark Seaton View Post

If you are after easy intergration and smooth on/off axis response, crossovers below 500Hz are required, desireable, and easily accomidated by midranges currently available. Jeff Bagby had noted on HT Guide that his free software would allow you to import the impedance of a measured or modeled woofer to design the crossover around. I suggest that some invest the time to attempt a 2nd, 3rd or 4th order crossover on the woofers they have in mind with the modeled impedance of the alignment they intend.

I agree with you about trying and attempting different alignments to see what happens and what the results are. I prefer to have the woofer or driver in hand to measure or model its characteristics. Since I can't afford to buy 3 or 4 varieties of different drivers to test, measure, and model, I must rely on preliminary graphs or charts to make a decision. Without these preliminary graphs or charts, a builder is somewhat flying blind and throwing caution to the wind to decide what to buy.

Quote:
Originally Posted by Mark Seaton View Post

I have a handful of models for the 10, 12, & 15" TD drivers that will work nicely for very high sensitivty, vented bass alignments which will nicely cross in the 200-350Hz range. Low frequency extension is limited, but that's what subwoofers and kWs of power are for. 96-103dB @ 2.8V @1m is not all that hard, and can be had in anywhere from 60-260L depending on how low you really want to go. Since there is a lot of interest outside of the DIY world, I'm looking at such a configuration to allow a passive variation on my Catalyst, which John's drivers do a nice job of enabling.

I would love to see your models. I will PM you shortly. Thanks for the response, I appreciate it greatly.

Chuck
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post #202 of 862 Old 07-03-2008, 12:20 PM
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Quote:
Originally Posted by chasw98 View Post

I am starting to grasp where you are coming from.

Good to hear. I don't want to come off implying this is way beyond anyone's abilities, as that is not really what I'm saying. I'm simply stating that the old-school "convention" makes many assumptions which are no longer true in these cases. There are tools that can easily model this. It just takes a few more steps and involves more variables to design the system rather than just one part. Note many who cling to the idea that a sealed box must have a Qts of 0.5 to possibly sound good would have a coronary over where most of my designs start.

Of course it's the sum of the parts that I'm interested, and often the end result is closer to those same ideals than the measured reality of the designs touting it.


Quote:


I agree with you about trying and attempting different alignments to see what happens and what the results are. I prefer to have the woofer or driver in hand to measure or model its characteristics. Since I can't afford to buy 3 or 4 varieties of different drivers to test, measure, and model, I must rely on preliminary graphs or charts to make a decision. Without these preliminary graphs or charts, a builder is somewhat flying blind and throwing caution to the wind to decide what to buy.

That is in fact my point. You can model this. Most don't or won't. Some tools allow you to more quickly view and adjust the interaction of the parts, but it can be done. Below 200Hz, the models are plenty accurate enough that you can almost always adjust for common variances found in real parts. Likewise, if you focus on the frequency response and impedance, you will find that the changes often have a much less significant impact than the alignment quantifications might suggest.

Start by modeling a driver in a program you can export both the magnitude and impedance data from. Now import that to a crossover program the same as you would your measured data, and start working through what range of crossover slopes you might need in your design. Take a look at baffle simulations and transpose some of that into the plan as well. As soon as you start modeling, what I'm referring to should become readily apparent.

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post #203 of 862 Old 07-03-2008, 01:21 PM - Thread Starter
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I get the feeling that many people are waiting for
the 'others' to do some work before they take the plunge
on the 3 way loudspeaker.

Im honestly just waiting until I actually finish my HT Room and then I will start my 3 way project.

First will be just building the TD12S sealed boxes and I will use them with my existing speakers....crossed over at around 500Hz. Then continue to upgrade from there.

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post #204 of 862 Old 07-05-2008, 08:45 PM - Thread Starter
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Quote:


I have a handful of models for the 10, 12, & 15" TD drivers that will work nicely for very high sensitivty, vented bass alignments which will nicely cross in the 200-350Hz range. Low frequency extension is limited, but that's what subwoofers and kWs of power are for.

Mark, did you model any sealed designs?

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post #205 of 862 Old 07-05-2008, 09:38 PM
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I don't have much of anything at home here for measured response curves. Here is a curve from the pair of TD15M apollo's and a pic of the cabinet. Mic was at 2m away, height at the center of the horn between the TD15M's. Things are time gated and using the praxis "flex window" so data below 250Hz is not accurate. Above there is fine though. No smoothing applied. The scale is quite large, but it should give you an idea of the extension of the TD15M.





I'll have some good data on several of the drivers soon. I planned to have the baffles cut this week but my CNC had a bad Geckodrive. Replacement came in thursday so it's up and running again. Next week I can knock out some cabinets.

John

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post #206 of 862 Old 07-06-2008, 09:55 AM - Thread Starter
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What kind of power should I give the TD12s drivers??

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post #207 of 862 Old 07-06-2008, 08:57 PM
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why are folks shooting for a 3-way, when the ae drivers are so capable? (actually a number of 15" drivers seem capable up to around 1.2khz or so these days).

seems like any td15 mated to a good compression driver-horn/waveguide around ~1.5khz would work just fine. geddes pushes the little b&c compression driver down to around 1khz. parham runs the same down to 1.6khz. the slightly more expensive bms (4550/4552nd) would seem fine as well down to 1.5khz or so. the 1086 horn seems to do quite nice off-axis as does the jbl waveguide (the $10 replacement part, i forget the number). the dds-eng90 pics posted by jj were a total disappointment, as that waveguide looked quite promising.

as most folks know, a big benefit of the two-way is the controlled directivity. a 90degree horn is down 6db the same as the td15 inch drivers in the 1.5khz (crossover) region or 1.1 khz for typical 15's. a good compression driver will hit 110db with a single watt, so 120db headroom is within practical limits. the omni-directional midrange idea would just seem to create floor/ceiling/wall reflection problems, added expense in driver and amplifier, added complexity, etc.

so, given that much is lost in going to a three way design, what is gained?

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post #208 of 862 Old 07-07-2008, 12:39 AM
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Turns out the TD15m isn't quite the miracle worker I initially thought. It is still very clean up to and well past 2khz, however, the off axis response in these uppermost registers leaves some to be benefited from with a smaller driver, such as a 6"er, also, the ribbon tweeter, being the current weak point in the system could also benefit from a higher crossover, such as 3Khz. I think this is the idea behind the current new wave of design ideas.

Many people do not like the use of horn loaded compression drivers in home environments, hence the use of the ribbon here. Of course, if he were to start using horn loaded drivers, a number of different designs become possible here because they are about the only tweeters truly suited for this application.
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post #209 of 862 Old 07-07-2008, 09:00 AM
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Originally Posted by armystud0911 View Post

Turns out the TD15m isn't quite the miracle worker I initially thought. It is still very clean up to and well past 2khz, however, the off axis response in these uppermost registers leaves some to be benefited from with a smaller driver, such as a 6"er, also, the ribbon tweeter, being the current weak point in the system could also benefit from a higher crossover, such as 3Khz. I think this is the idea behind the current new wave of design ideas.

Many people do not like the use of horn loaded compression drivers in home environments, hence the use of the ribbon here. Of course, if he were to start using horn loaded drivers, a number of different designs become possible here because they are about the only tweeters truly suited for this application.

One guy on AE speaker's forum is doing a 3 way with the Altec 902a for the top end on a B&C ME10 horn. It's something I was interested in due to reasonable cost, small size regarding horn, and seemingly good match with sensitivity as well. He reported 3D sound on the highs.
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post #210 of 862 Old 07-07-2008, 09:35 AM
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Guess directionality at the top of the working range of the driver is to be expected. Heck few complain that most ribbons even top dollar ones get only about +/- 5 deg working vertical range. (so you can't stand up). I'll just aim the darn thing directly at me since its for music.
If you are 3m or more away it prob would be of no issue. 90 deg @ 1.5k polar response for TD15 would be super excellent (matches my DDS horn which i plan cross at 1.7k). Remember reading Geddes saying something like 800-900Hz for his 15s speakers. I intend to play around and hope to reach 2k, 2.5k if possible and see if i can squeeze more quality treble out of the CD + horn combo.

I just hope it will be very high in midrange resolution for the 15 incher. I'll be very happy if it can come close to the top stuff from Scanspeak/Skanning etc.
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