Lilmike's Cinema T-6 - Page 2 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #31 of 192 Old 09-05-2011, 10:36 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by LTD02 View Post

"Even with my new ewaves..."

what woof are you running, what amp?

Amp is my Denon 988.

I know where the problem is...

I'm running really cheap midbasses - MCMs discontinued 55-1740 10. The one with the self-demagnetizing motor (it's a feature....). Seriously - I've measured a drop of over one unit of BL on these since I purchased them. They aren't really even worth the $15 each I spent. Funny - you do get what you pay for. Who knew??

I just don't have the funding to purchase proper midbass drivers at the moment, so I used what I had on the shelf. Truth be told, they belong in a landfill, but that costs money too, so I'll just listen to them for now.

Not really that big a deal to be honest - I can now hit reference levels cleanly, they're a huge improvement over the MTMs that I was using. They're not "that" bad, they just don't have that last bit of impact I want when they're getting pushed hard. When they can't deliver any more, they just start to sound harsh, this is up near +10 dB on the volume knob territory though. Compared to my old MTMs, they just sound so much cleaner and clearer in my room. Controlled directivity for the win.

Like the rest of the system - this is all temporary. In addition to several new sub designs, I am playing around with some new ideas for mains, just need to get from the "hornresp simulations" phase to the "dimensioned plan" phase.
lilmike is offline  
Sponsored Links
Advertisement
 
post #32 of 192 Old 09-05-2011, 10:37 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by iGuitar93 View Post

Thanks!

Would this work as a high pass?
http://www.parts-express.com/pe/show...number=266-246

And is a dayton 240 a good amp to use?

Some folks have used the Fmods successfully. I have not used them since my car stereo days. The Dayton amp should be OK, which driver are you planning to use?
lilmike is offline  
post #33 of 192 Old 09-05-2011, 10:45 AM
Member
 
iGuitar93's Avatar
 
Join Date: Aug 2011
Posts: 61
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by lilmike View Post


Some folks have used the Fmods successfully. I have not used them since my car stereo days. The Dayton amp should be OK, which driver are you planning to use?

A dayton classic 10. Is there an amp that would be better that wouldn't cost $200?
iGuitar93 is offline  
post #34 of 192 Old 09-05-2011, 11:32 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
That is a fine combination, but be aware that the DCS255-4 driver (Dayton Classic 10 Subwoofer) can be driven past xmax in this box with that amp.

It is only a 200 watt driver, but it reaches xmax in this box with 100 watts. It hits 115 dBs at that point too, so I wouldn't worry too much, in my opinion you would not want to push a single ten much farther.

Be sure to get the amp without bass boost, and if you're comfortable changing resistors, you can swap two resistors to set your highpass where it needs to be. Instructions are here.
lilmike is offline  
post #35 of 192 Old 09-05-2011, 11:37 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,904
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 111 Post(s)
Liked: 831
"I'm running really cheap midbasses..."

ah man lilmike, you deserve better! put a $20 spot on your plans and nobody will complain, they are all good...if i built one of your horn subs, i'd have zero issues shooting you a $50 spot (well, that is because i would build multiples...:-))

for a good main, check this out:
http://www.avsforum.com/avs-vb/showt...6#post20908406

Listen. It's All Good.
LTD02 is online now  
post #36 of 192 Old 09-05-2011, 11:41 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Saw those. I'm exploring things that are somewhat similar, but have a few more drivers attached.

Oh, I'll get better stuff, rest assured. This is all temporary, all my spare change is going into the remodel the house so I can have my own theater fund....

Right now the room has all it needs.

When I get my theater built - it's gonna get interesting. Might not get the extension MK and Not have, but I will hit the SPLs that Not does....
lilmike is offline  
post #37 of 192 Old 09-05-2011, 09:40 PM
Senior Member
 
paulspencer's Avatar
 
Join Date: Feb 2004
Location: Melbourne, Australia
Posts: 424
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by lilmike View Post

Regarding the comparisons:

The W8-740 is an 84 dB driver at a watt per Tang Band's specifications. A sealed or vented box with the driver as a direct radiator will produce that 84 dB with a watt, provided the cabinet loading allows it.

The T-6 makes ~92 dB at that same watt in above 30 Hz. That's an increase of 8 dB, which is pretty significant. When I model the driver in a ported cabinet with a 30 Hz tune, I get about 86 dB at a watt, and the driver reaches excursion limits/thermal limits at 128 watts, same as in the T-6, which yields about 108 dB at a meter.

When I was pushing things, I've measured peak SPLs of 117 dB 1M groundplane at ~25% THD from one T-6 loaded with the W8-740C. Though I was definitely into power compression at this point, the driver was not complaining.

For plotting, I export the SPL from HornResp, then import it into REW.

Thanks for the reply. Is that 8 db based on a hornresp sim or actual measurements? I ask because I have wondered how accurate the sims are in terms of efficiency. I recall someone saying it over-estimated efficiency, not sure where. Might have been volvotreter. When I simulate a driver without a horn in hornresp (0.1cm long horn matching driver SD), it seems to be a bit optimistic on 1w1m. I would like it to be right, but is it?
paulspencer is offline  
post #38 of 192 Old 09-06-2011, 12:32 AM
AVS Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia; now run by adults.
Posts: 5,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Liked: 42
Did you enter the correct voltage?
A9X-308 is offline  
post #39 of 192 Old 09-06-2011, 06:11 AM
Member
 
jbelljbell's Avatar
 
Join Date: May 2009
Posts: 190
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
applause from me.... I only stop by on occasion and saw this thread.

way to go mike...

Yea, I remember you buying out the last of the 55-1740's. Not bad for what they are, I think I've gotten my $15 out of each one.
jbelljbell is offline  
post #40 of 192 Old 09-06-2011, 09:29 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by paulspencer View Post

Thanks for the reply. Is that 8 db based on a hornresp sim or actual measurements? I ask because I have wondered how accurate the sims are in terms of efficiency. I recall someone saying it over-estimated efficiency, not sure where. Might have been volvotreter. When I simulate a driver without a horn in hornresp (0.1cm long horn matching driver SD), it seems to be a bit optimistic on 1w1m. I would like it to be right, but is it?

The 92 dBs was measured with relatively accurate gear, the 86 dB was a simulated number from a simple ported box with the same tune. The 92 dB is real, and should actually be stated as 93 dB now that I've done the math. I'm not gonna cut open one of the T-6s, pull a driver out, and build a poorer-performing ported box as a science experiment - I'll leave that for someone else to do.

During groundplane testing of one of the T-6s, I measured an average SPL of 92.68 dB between 27 Hz and 105 Hz at one meter, groundplane with 2.02 volts of drive.

That data is presented in post 1, and is plotted with a comparison to the model at 2.00V.

The hornresp simulation at 2.00 V indicates an average SPL of 92.67 dB through this same range.

As far as I am concerned - round this to 93 dBs and they match. This is well within the error bounds of my measuring instrumentation.

If you measure what you're working with, model what you've measured, then build what you've modeled, the results will be quite close to the predictions.

My T-6 model could actually be tweaked a bit to more accurately represent what I actually built (side mouth), but it is definitely in the ballpark.
lilmike is offline  
post #41 of 192 Old 09-06-2011, 09:32 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by jbelljbell View Post

applause from me.... I only stop by on occasion and saw this thread.

way to go mike...

Thanks. It's actually your fault - you put the single sheet idea into my head over at DIY. I hate wasting plywood.

Yea, I remember you buying out the last of the 55-1740's. Not bad for what they are, I think I've gotten my $15 out of each one.

Me too, just bummed that mine have shifted as much as they have. Essentially unusable in anything other than a sealed box now.

Thanks for stopping by Jim.
lilmike is offline  
post #42 of 192 Old 09-06-2011, 10:51 AM
AVS Special Member
 
Kimeran's Avatar
 
Join Date: Sep 2009
Posts: 1,201
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 114
hey mike,
I am having a problem finding the w8-740c but I have found the w8-740P and didnt know if that would work as I do not know the difference between the two.

I have also found plenty of dayton 8" drivers and the classic is a little cheaper so I may go that route.

However, I still may go with a 10" as there are some that are in the same price range as some of the 8s and if that gets 6db more than what I have already that could really rattle the bones...

This is the 10 i was looking at,
http://www.parts-express.com/pe/show...number=295-202

Trying to enjoy the simple things in life.

 

Steam: madbrayniak

Kimeran is offline  
post #43 of 192 Old 09-06-2011, 11:05 AM
Advanced Member
 
blackoper's Avatar
 
Join Date: Sep 2006
Location: Louisville, KY
Posts: 553
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 23
what do we have for good 100wattx2 pro audio amps for using two of the DCS255-4 on the cheap? I guess I could always use an old receiver and use direct inputs to drive the subs as this would provide 100 watts to both easy enough.

Also since this is a much cheaper build, would we be able to use a car audio type inline high pass instead of having to go the minidsp route like I did with the F20s or should I just bite the bullet and get a 2x4 minidsp for eq and highpass, etc
blackoper is online now  
post #44 of 192 Old 09-06-2011, 11:49 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by Kimeran View Post

hey mike,
I am having a problem finding the w8-740c but I have found the w8-740P and didnt know if that would work as I do not know the difference between the two.

I have also found plenty of dayton 8" drivers and the classic is a little cheaper so I may go that route.

However, I still may go with a 10" as there are some that are in the same price range as some of the 8s and if that gets 6db more than what I have already that could really rattle the bones...

This is the 10 i was looking at,
http://www.parts-express.com/pe/show...number=295-202

Get the 10. I recommended it here, and discussed it a little more here.

Of course - one of these is a bit cheaper than a pair of those, and will make the same amount of noise from a single cabinet.

I'd still suggest a pair....
lilmike is offline  
post #45 of 192 Old 09-06-2011, 11:57 AM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by blackoper View Post

what do we have for good 100wattx2 pro audio amps for using two of the DCS255-4 on the cheap? I guess I could always use an old receiver and use direct inputs to drive the subs as this would provide 100 watts to both easy enough.

Also since this is a much cheaper build, would we be able to use a car audio type inline high pass instead of having to go the minidsp route like I did with the F20s or should I just bite the bullet and get a 2x4 minidsp for eq and highpass, etc

I'd just use a plate amp and mod the built-in filter to get the highpass right. It will be good enough. Fmods might work OK, I don't use them so I don't know.

If you have to have rackable gear, the Behringer A500 is a little too big, the Audiosource Amp100 is a little too small. PE is supposedly going to sell a rack-sized 230 watt sub amp one of these days, though the ETA is in October now.
lilmike is offline  
post #46 of 192 Old 09-06-2011, 02:47 PM
AVS Special Member
 
Kimeran's Avatar
 
Join Date: Sep 2009
Posts: 1,201
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 114
Quote:
Originally Posted by lilmike View Post

Get the 10. I recommended it here, and discussed it a little more here.

Of course - one of these is a bit cheaper than a pair of those, and will make the same amount of noise from a single cabinet.

I'd still suggest a pair....

Yea that is what my goal is to have 2 to start out with and maybe add a third in a back corner. Hence I am on the fence about starting with 10s or 8s as the 8s will be slightly cheaper. However, I can say that i have narrowed it down between the two dayton classic drivers.

Trying to enjoy the simple things in life.

 

Steam: madbrayniak

Kimeran is offline  
post #47 of 192 Old 09-06-2011, 06:55 PM
Senior Member
 
paulspencer's Avatar
 
Join Date: Feb 2004
Location: Melbourne, Australia
Posts: 424
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by lilmike View Post

The 92 dBs was measured with relatively accurate gear, the 86 dB was a simulated number from a simple ported box with the same tune. The 92 dB is real, and should actually be stated as 93 dB now that I've done the math. I'm not gonna cut open one of the T-6s, pull a driver out, and build a poorer-performing ported box as a science experiment - I'll leave that for someone else to do.

I certainly don't expect it.

That's a good result in terms of the accuracy of the sims vs measurements. Good to know. I have some builds coming up at some point that will be large, too big to do test boxes. I'd hate to expect 96 db then actually get 91! Some Rythmik 20 Hz tapped horns under the floor coming in through corner openings, dual 12" drivers. Planned for a long time, still need to get around to it.
paulspencer is offline  
post #48 of 192 Old 09-06-2011, 07:41 PM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by Kimeran View Post

Yea that is what my goal is to have 2 to start out with and maybe add a third in a back corner. Hence I am on the fence about starting with 10s or 8s as the 8s will be slightly cheaper. However, I can say that i have narrowed it down between the two dayton classic drivers.

Use the 10s.

Seriously.

The 8s take less power and make less noise, and they both use the same size cabinet.
lilmike is offline  
post #49 of 192 Old 09-20-2011, 04:59 PM
AVS Special Member
 
cubdenno's Avatar
 
Join Date: Dec 2008
Location: Cham-Bana Illinois
Posts: 1,436
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 54
So the JBL GTO 10" will work in this enclosure? Just alter the width?

Great plans by the way!

XBL-Steelhouse1

"No one wants to fight the naked guy."
cubdenno is offline  
post #50 of 192 Old 09-21-2011, 12:09 PM
Advanced Member
 
javygonx's Avatar
 
Join Date: Jul 2010
Location: Puerto Rico
Posts: 904
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Question.. Is this Cinema T-6 a little version of the Cinema T-20?
javygonx is offline  
post #51 of 192 Old 09-21-2011, 12:43 PM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by javygonx View Post

Question.. Is this Cinema T-6 a little version of the Cinema T-20?

Not at all, there isn't a T-20 (yet).

The F-20 is a 20 cubic foot, front-loaded horn that uses a 15" driver. It has a measured ~19 Hz -3 dB corner in a 2pi setting.

The T-6 is a 6 cubic foot tapped horn that can be loaded with an 8" or 10" driver. Widths can be varied to better match the horn to the driver in some cases. It has a measured ~27 Hz -3 dB corner in a 2pi setting. Though it may look like it is a bigger version of the tapped Insubnia, it was actually a complete refold.
lilmike is offline  
post #52 of 192 Old 09-21-2011, 12:46 PM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by cubdenno View Post

So the JBL GTO 10" will work in this enclosure? Just alter the width?

Great plans by the way!

Thanks.

With the GTO 10, I'd suggest 11.75" wide internally. I modeled with the manufacturer-supplied specs, so of they are accurate, it should work OK.

Smaller is not better with the larger drivers, compression gets pretty high. Some drivers may benefit from higher compression to flatten the peaks in the response a bit.
lilmike is offline  
post #53 of 192 Old 10-01-2011, 09:54 AM
AVS Special Member
 
mynym's Avatar
 
Join Date: Nov 2004
Location: Columbus, OH
Posts: 1,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 14
With the higher tuning of this enclosure I bet this would make for a great Car Audio sub.

Thanks for documenting this. I posted a reply in Erich's flat pack thread wondering if we could get this flatpacked.
mynym is online now  
post #54 of 192 Old 10-14-2011, 04:29 PM
Newbie
 
emax's Avatar
 
Join Date: Dec 2005
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
This is my very first post. I'll keep it brief:

Lurking here for a few months, lilmike has taught me most of what I know about tapped horns.

This design has finally provoked me to cut wood.

I modeled most of the 10in drivers on the list in post #2, and chose the Fi Audio X10 both for price ($109 direct) and because it looked the flattest in hornresp.

While I'll probably go with this driver anyway, the flat response was due to entering Sd incorrectly (338 vs 310cm2) and for lack of an Le spec, using 3.2mH instead of the real spec (which I got from them via email) of 1.75mH.

Plugging in the real specs, this driver looks pretty much the same as the rest of the 10s.

HOWEVER, adding an extra 3-4mH and an extra 0.05Ohms impedance per mH, makes this look SUPER-flat.

This begs a question for the advanced Hornresp user, and anyone who's compared actual measurements with modeled response:

Since the added 4mH series coil is essentially a 159Hz low-pass filter, (assuming average 4Ohm impedance for the driver,) and this resulted in a MUCH flatter response at the low end, will using a 1st order low-pass filter in the real world, in lieu of this inductor (via DSP, etc,) similarly flatten the response???

Will using a "serious" low-pass filter further flatten the response down low? (18 or 24db/octave via DSP)

Have I been overly critical and nit-picky looking for a VERY flat response down low in hornresp models, or is the roughly +/- 3db waviness most of these 10's show in lilmike's T-6 good enough to flatten out provided the finished cabinet is fed signal only in the pass band?

Short of stepping up the the complexity of akabak, is there any way to coax hornresp to model anything but a full-range signal?

Any guidance appreciated.

THANKYOU LILMIKE for all of your hard work, encouraging MANY people like myself to get into this hobby.

Eric.
emax is offline  
post #55 of 192 Old 10-15-2011, 01:18 PM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by emax View Post

This is my very first post. I'll keep it brief:

Lurking here for a few months, lilmike has taught me most of what I know about tapped horns.

This design has finally provoked me to cut wood.

I modeled most of the 10in drivers on the list in post #2, and chose the Fi Audio X10 both for price ($109 direct) and because it looked the flattest in hornresp.

While I'll probably go with this driver anyway, the flat response was due to entering Sd incorrectly (338 vs 310cm2) and for lack of an Le spec, using 3.2mH instead of the real spec (which I got from them via email) of 1.75mH.

Plugging in the real specs, this driver looks pretty much the same as the rest of the 10s.

HOWEVER, adding an extra 3-4mH and an extra 0.05Ohms impedance per mH, makes this look SUPER-flat.

This begs a question for the advanced Hornresp user, and anyone who's compared actual measurements with modeled response:

Since the added 4mH series coil is essentially a 159Hz low-pass filter, (assuming average 4Ohm impedance for the driver,) and this resulted in a MUCH flatter response at the low end, will using a 1st order low-pass filter in the real world, in lieu of this inductor (via DSP, etc,) similarly flatten the response???

Will using a "serious" low-pass filter further flatten the response down low? (18 or 24db/octave via DSP)

Have I been overly critical and nit-picky looking for a VERY flat response down low in hornresp models, or is the roughly +/- 3db waviness most of these 10's show in lilmike's T-6 good enough to flatten out provided the finished cabinet is fed signal only in the pass band?

Short of stepping up the the complexity of akabak, is there any way to coax hornresp to model anything but a full-range signal?

Any guidance appreciated.

THANKYOU LILMIKE for all of your hard work, encouraging MANY people like myself to get into this hobby.

Eric.

Best.
First.
Post.
Evar.

And not just cause you said thanks. Seriously - thanks for taking the time to learn. Questions are always welcome, but it is SOOO much easier to answer things when there is a foundation present to work with.

Remember that your room will ruin that ruler flat response. I wouldn't sweat it. You can add the inductor outside the box easy enough. I've tested with and without them - there is an impact, but I am of the opinion that there is more going on there than a simple 159 Hz lowpass. Remember - impedance is not at all a constant in a resonant enclosure like a tapped horn.



Todd's 38 Hz tapped horn - design by Volvotreter.
Blue = no inductor, red = with inductor, same amp/drive level, same distance, same setting.

I think that we're seeing the inductor work to trim the peaks in the response, because I see more getting cut at the peaks than in the saddle, as well as the SPL decrease with higher frequency due to the lowpass. As I understand it ( and - I don't fully...), inductors don't like to see changes in current. Low impedance = high current. Impedance minima are close to (but not exactly) where I see the most impact from the coil on the above measurement. The lag may be due to phase.

Use the inductor if you want, they do work like Hornresp says they will. The additional resistance is not that big of a deal and they don't cost that much. In my opinion, worrying about a dead-flat 2pi response is silly if you plan on listening to it in a typical room. The room will ruin that ruler-flat response, unless you are super lucky, use multiple subs, or both....

If you do elect to build the T-6 with the Fi X-10 driver, please let me know the accurate specs, as well as how it works. Actual measurements would be great. I will definitely include it in the tested and verified drivers list if it works.
lilmike is offline  
post #56 of 192 Old 10-16-2011, 07:35 PM
Advanced Member
 
Audiophile34's Avatar
 
Join Date: Apr 2011
Location: Detriot Mi area
Posts: 561
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Would the kicker 10" in this add work for this enclosure?


http://app.streamsend.com/c/14849105...eCarStereo.com



Considering 2 to supplement my current set up..
And at 80 bucks seems like a great deal...

My first DIY project. A dual, dual opposed setup

www.avsforum.com/avs-vb/showthread.php?t=1345494
Audiophile34 is offline  
post #57 of 192 Old 10-16-2011, 11:34 PM
Newbie
 
emax's Avatar
 
Join Date: Dec 2005
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
lilmike, thanks for the reply! This is fun.

I gather several kernels from your thorough response:

1. Most importantly, given the plot attached, as well as your observations thereof, adding a low-pass filter, in this case an actual inductor, has a frequency-dependent response, attenuating where's it's supposed to (above the pass-band) and not so much where it's not (quite a bit of loss there too it seems,) but doesn't alter the basic "shape" of the response anywhere.

2. The question still stands as to whether there is a way to feed hornresp models a limited frequency band for modeling.

3. The standing question may be moot, given the uniform behavior of the model lilmike posted in the pass band, with a real low-pass filter.

4. Stop asking questions, order the drivers, cut wood, smile.

Edit: Sun pm: I wasted a trip across town to wheel a backup sub cabinet into place... It seems it's possible to fry a "4000W RMS" driver with ****** dj signal when driven by 1600W RMS. Nearly $300 each to have original EV MTL-1x drivers re-coned, (parts + labor,) $800 for a new pair, or another $250 for a pair of crappy Chinese 18in subwoofers, which lasted a whopping 4 months. I'm ready to kick them to the curb (they never did anything south of about 45Hz) and go with 4x lilmike's T-6 cabinets. The 3 hours it took me to shave the speaker reliefs, (manually, with a utility knife,) and grind the pole plates (!!) to fit the Chinese pair into the MTL-1x cabinets, would have been MUCH better spent cutting new wood for a new alternative.
emax is offline  
post #58 of 192 Old 10-17-2011, 01:08 PM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by emax View Post

lilmike, thanks for the reply! This is fun.

I gather several kernels from your thorough response:

1. Most importantly, given the plot attached, as well as your observations thereof, adding a low-pass filter, in this case an actual inductor, has a frequency-dependent response, attenuating where's it's supposed to (above the pass-band) and not so much where it's not (quite a bit of loss there too it seems,) but doesn't alter the basic "shape" of the response anywhere.

As the behavior of the inductor is heavily dependent on the impedance, and impedance varies - it is not that simple. The inductor acts as more than a simple low-pass filter. Part of the losses were undoubtedly a result of the clip-leads I used to jumper the inductor into the circuit. The separated traces make it a little easier to see what is going on in my opinion, so I did not worry about correcting the drive levels.

Quote:
Originally Posted by emax View Post

2. The question still stands as to whether there is a way to feed hornresp models a limited frequency band for modeling.

Not that I am aware of.

Quote:
Originally Posted by emax View Post

3. The standing question may be moot, given the uniform behavior of the model lilmike posted in the pass band, with a real low-pass filter.

They work according to the model.

Quote:
Originally Posted by emax View Post

4. Stop asking questions, order the drivers, cut wood, smile.

Well said. No model will ever trump a real measurement. Sawdust FTW.

Quote:
Originally Posted by emax View Post

Edit: Sun pm: I wasted a trip across town to wheel a backup sub cabinet into place... It seems it's possible to fry a "4000W RMS" driver with ****** dj signal when driven by 1600W RMS. Nearly $300 each to have original EV MTL-1x drivers re-coned, (parts + labor,) $800 for a new pair, or another $250 for a pair of crappy Chinese 18in subwoofers, which lasted a whopping 4 months. I'm ready to kick them to the curb (they never did anything south of about 45Hz) and go with 4x lilmike's T-6 cabinets. The 3 hours it took me to shave the speaker reliefs, (manually, with a utility knife,) and grind the pole plates (!!) to fit the Chinese pair into the MTL-1x cabinets, would have been MUCH better spent cutting new wood for a new alternative.

It is always possible to kill drivers.....if you try hard enough.

Not sure the T-6 is that great for a PA sub - they are great with music and movies though. Even with a 10, they are small drivers, with small coils and small limits....

I guess if you used enough of them, and highpassed them to avoid damage, they should work OK. There are some good DIY PA designs out there - lots of discussion over at DIYAudio, there is only a little bit here. I drew up a 33 Hz PA-oriented tapped horn that used the Dayton PA380-8 15 a while back, it turned out OK, but there is a bit of room for improvement on that one (namely - I'd use 3/4" ply...or better bracing, or both). Waiting on some SPL and impedance measurements to see if anything else needs to be fixed.
lilmike is offline  
post #59 of 192 Old 10-17-2011, 01:18 PM - Thread Starter
AVS Special Member
 
lilmike's Avatar
 
Join Date: Dec 2009
Location: Pacific Northwest
Posts: 2,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 73
Quote:
Originally Posted by Audiophile34 View Post

Would the kicker 10" in this add work for this enclosure?


http://app.streamsend.com/c/14849105...eCarStereo.com



Considering 2 to supplement my current set up..
And at 80 bucks seems like a great deal...

While both work OK, the 2010 Comp VT 10" 4-ohm version is a better fit than the 10" 2-ohm one.

If you build with these - let me know which one you used and how they work, I'll update the lists. Measurements would be great if possible.
lilmike is offline  
post #60 of 192 Old 10-18-2011, 12:55 AM
Newbie
 
emax's Avatar
 
Join Date: Dec 2005
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The EV MTL-1x is well-regarded as a good "PA" sub. Maybe it's good for live sound reinforcement, but it's awful for recorded music, ala DJ's spinning.

I thought I recalled being disappointed south of 45Hz, but it looks more like 55Hz from EV's published response plot for these. (attached, if I can do so with a post count of TWO.)

While there are few ways to make live sound south of 60Hz, (harmonics of a bass guitar, pipe organs, synth bass are clear exceptions,) playing recorded music, in a DJ setting, calls for the same class of gear we enjoy at home... just able to play much louder. I see no reason why a great design like the T-6, which makes the most of a single sheet of wood, and a class of driver that's readily available, cheap, and handles huge power (relatively speaking) can't make an excellent "PA" sub for DJ'ed music.

Four of these cabinets, given thermal and excursion limits, seems to blow even a pair of EV MTL-1x cabinets, (which I can't fit into the corner I need to fill,) out of the water, while extending usefully 25Hz farther south. Instead of driving a single cabinet with TWO nice Crown MA2402's bridged mono, (1600W at 8ohms to each driver,) I'll use one amp to drive all 4 cabinets, (800W at 8ohms for each pair,) cranking out the same SPL, with MUCH lower extension. If I fry drivers, I'll replace, or even recone them... I'm still waiting for an answer from Fi about what re-coning costs for these, their cheapest product. (BTW, while these amps are capable of driving a lower impedance load, with more power, listening proved they sounded best with an easy 8ohm load. Damping factor increase responsible?)

An added benefit to likmike's T-6 design, using the side-mouth variant, is that the gang of 4 cabinets fits into a very small space (72h x 48w x as shallow as possible... 12-13in) under existing flown cabinets, and allows all 4 mouths to be ganged together at gut-height for woofer surfing, a popular sport on any club dance floor.

Again, these seem to offer a very good compromise of low build effort, low extension, max output, efficiency, value. I've been trying to fill this magic corner, (in which I'll also experiment with corner-loading, but this doesn't offer much "surfing" potential,) for 6 months, and this is the first design where I could achieve the SPL I'm looking for in the alotted corner space within a reasonable budget. Just like Danley designs his cabinets to be an integer divisor of a semi truck load for efficient transportation between gigs, a stack of 4 of these T-6 cabinets fills my corner perfectly, with no wasted space. Plenty of other designs discussed here, and on other DIY forums looked great, but I couldn't fit enough of them in this corner to fulfill my design goals. (I even considered stacking 8-9 Insubnia Anarchy boxes!)

4 of these, built with the Fi X10, model with an efficiency of about 97dB/1W, which pretty much exactly matches my top boxes.

I've yet to find anyone back the idea up with a credible study, but "rumor" has it that juicy sub-bass, south of 50Hz, makes bar patrons want to drink more, whereas sparking highs make bar patrons want to urinate more. Our top boxes run out of gas at 16khz, and I'm fine with that

The last benefit of this experiment is that if they don't work out at the club, just like a retired draft animal, these will find their way home to pasture, where they can retire comfortably on a diet of mildly-amplified vinyl, and the occasional action movie.
LL
emax is offline  
Reply DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off