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4 cinema F-20's - Page 3

post #61 of 661
Thread Starter 
Quote:
Originally Posted by chrapladm View Post

Congrats on the new boy!!

Are you going to watch the tumbler scene in Batman perhaps?

I remember you commenting a while ago on that scene shaking you pretty well so I wondered how these will do.

I sure will.

Hey guys, I also noticed that when I ran a 115 db sine wave at 10hz with 15% distortion it was much more pleasant to listen to than before, Reason? Meaning I have no problem running 15% distortion with these subs as the sound was still good(with sine waves).

Basically I could run any 10hz movie scene at reference in my room with this system and have awesome bass from 20hz and above.
post #62 of 661
correct me if I misunderstand. but isn't the ability of these f 20's to suck up driver distortion one of there strongest assets? or is it just the absurd SPL at low power? or maybe the sq? jeez the way I look at it, the only thing that could be a negative about these cinemas, is the size.. so if that isn't a problem you are going to be happy with these...
post #63 of 661
Thread Starter 
Quote:
Originally Posted by Audiophile34 View Post

correct me if I misunderstand. but isn't the ability of these f 20's to suck up driver distortion one of there strongest assets? or is it just the absurd SPL at low power? or maybe the sq? jeez the way I look at it, the only thing that could be a negative about these cinemas, is the size.. so if that isn't a problem you are going to be happy with these...

We shall see, they measure better than expected for a horn in my room. Tomorrow I get a chance to listen to them carefully. They are big.
post #64 of 661
Congrats for the boy and new toys.

I wonder how pulse lab scene sounds now?
post #65 of 661
horns dont suck up distortion, they load a driver more than other enclosures (rather, impedance match the cone to the air) so there is less excursion therefore less distortion, but below the knee (tuning so to speak) excursion sky rockets therefore distortion does (no more loading) so the horn amplifies the distortion as well as everything else.

I hope there is more truth to that than misperceptions, I am not very knowledgeable on them but believe the above to be accurate.
post #66 of 661
Quote:
Originally Posted by MKtheater View Post

OK, did some more measuring. Here are some distortion graphs and a compression sweep. I stopped due to the wife yelling upstairs. The 10hz and 15hz distortion tests are at 10% and the 20hz is at 4.58%.

Winner, winner, chicken dinner....

Impressive the amt of clean spl below tuning point.....

The drivers don't have incredible excursion below tune in a sealed rear chamber, front loaded horn (flh); the horn 'amplifies' distortion products.

I bet you never exceed 500w to all four....

Glad to hear they perform well...i was present for the initial fire-up and testing of the prototype. It is the BEST bang for buck enclosure available. Lilmike has done an uncredible job of designing an easy to build, powerful enclosure.

JSS
post #67 of 661
Thread Starter 
Quote:
Originally Posted by kryptonitewhite View Post

horns dont suck up distortion, they load a driver more than other enclosures (rather, impedance match the cone to the air) so there is less excursion therefore less distortion, but below the knee (tuning so to speak) excursion sky rockets therefore distortion does (no more loading) so the horn amplifies the distortion as well as everything else.

I hope there is more truth to that than misperceptions, I am not very knowledgeable on them but believe the above to be accurate.

That sounds about right to me.
post #68 of 661
MK,

How did you do this part "compression sweep"? Thanks.

James
post #69 of 661
Thread Starter 
Quote:
Originally Posted by exojam View Post

MK,

How did you do this part "compression sweep"? Thanks.

James

I just ran a sweep, then turned the MV up 5 db's, then did it again, and again. I then just clicked all spl or something like that which shows all the measurements at once.
post #70 of 661
Quote:
Originally Posted by MKtheater View Post

I just ran a sweep, then turned the MV up 5 db's, then did it again, and again. I then just clicked all spl or something like that which shows all the measurements at once.

But how than do you see when compression is taking place? Thanks.

James
post #71 of 661
Thread Starter 
Quote:
Originally Posted by exojam View Post

But how than do you see when compression is taking place? Thanks.

James

As I turn it up the response will change and not get the full db I input. I did not get any compression within the range I was looking but that last sweep is where 10% distortion hits 10hz and 15hz. Below the knee distortion rises before compression in my room. Of course above 15hz the distortion gets low with no compression. When I ran 15% distortion at 10hz and 15 hz it sound like louder bass where when I ran the CS subs above 10% THD sound was aweful, any ideas why? I never tried 15% THD at 20hz as it would have been much too loud.
post #72 of 661
MK,

Thanks for the response. I thought that was how to tell when compression set in (since I actually think I asked someone else that before). It stinks getting old and forgetting things.

As for your question, I would not be able to answer that. I still remember ol Chuck (amp testing Chas) telling me if I ever had bass questions to go to Bosso for help.

James
post #73 of 661
WOW! 1 day and this thread has grown 3 pages already!

Looking good as always MK! Can't wait to "hear" your impressions fully dialed in.

EDIT: Congrats on the boy too!!!!

dbl
post #74 of 661
Thread Starter 
Quote:
Originally Posted by dbldare View Post

WOW! 1 day and this thread has grown 3 pages already!

Looking good as always MK! Can't wait to "hear" your impressions fully dialed in.

EDIT: Congrats on the boy too!!!!

dbl

Thanks.
post #75 of 661
Quote:
Originally Posted by MKtheater View Post


As I turn it up the response will change and not get the full db I input. I did not get any compression within the range I was looking but that last sweep is where 10% distortion hits 10hz and 15hz. Below the knee distortion rises before compression in my room. Of course above 15hz the distortion gets low with no compression. When I ran 15% distortion at 10hz and 15 hz it sound like louder bass where when I ran the CS subs above 10% THD sound was aweful, any ideas why? I never tried 15% THD at 20hz as it would have been much too loud.

MK,

The reason for the 'not so bad sound' is the decreased excursion of the drivers. They are actually moving less in the horn. The horn itself is amplifying the distortion components.

If the horn weren't there, the drivers would be at a far lower thd for the same amount of power input.

I hope that makes sense...

JSS
post #76 of 661
Thread Starter 
Quote:
Originally Posted by maxmercy View Post

MK,

The reason for the 'not so bad sound' is the decreased excursion of the drivers. They are actually moving less in the horn. The horn itself is amplifying the distortion components.

If the horn weren't there, the drivers would be at a far lower thd for the same amount of power input.

I hope that makes sense...

JSS

Makes sense to me.
post #77 of 661
Quote:
Originally Posted by MKtheater View Post

I used to have a DIY screen with the center XD material. I now have a complete seymour screen that is 10 inches bigger in diagonal and it is huge. It covers the front stage!! I love it! Very nice screen and worth every penny, matches great with my pioneer elite projector.

Just read the thread through again and holy cow that's a large screen! What model projector are you running. You say the Pioneer Elite but what model? I know you have complete control of lighting, but does it put out enough brightness (especially with an AT screen) for you?


dbl
post #78 of 661
Thread Starter 
Quote:
Originally Posted by dbldare View Post

Just read the thread through again and holy cow that's a large screen! What model projector are you running. You say the Pioneer Elite but what model? I know you have complete control of lighting, but does it put out enough brightness (especially with an AT screen) for you?


dbl

pro-fpj1 or JVC RS2 clone. The picture is amazing!!!
post #79 of 661
...and a smokin' deal when they were being clearanced! I missed that one, damn.
post #80 of 661
Quote:
Originally Posted by MKtheater View Post

pro-fpj1 or JVC RS2 clone. The picture is amazing!!!

Sorry off topic, and thanks again.


dbl
post #81 of 661
Thread Starter 
Quote:
Originally Posted by dbldare View Post

Sorry off topic, and thanks again.


dbl

No problem.
post #82 of 661
Quote:
Originally Posted by MKtheater View Post

I am not sure what I want but a RE-XXX 18 IB has been on my mind as well. I want to see where these take me as the look is just damn cool with that giant horn mouth. No drivers seen.

Ive seen pics and layouts of your room before but dont have them comitted to memory. Have you scratched down any idea how you would set up an IB in there?
post #83 of 661
Thread Starter 
Quote:
Originally Posted by kryptonitewhite View Post

Ive seen pics and layouts of your room before but dont have them comitted to memory. Have you scratched down any idea how you would set up an IB in there?

I would build a false wall.
post #84 of 661
how much space would that cut you down to? Manifolds or like Brian's IB3 wall? Did you sell all your EO2500s...what would you power them with?
post #85 of 661
Thread Starter 
If I were to buy the RE-XXX's I would buy the LG 14000 clones. I really don't know if I need them with my room gain.
post #86 of 661
I just KNEW you were gonna say that! Ya, you have me sitting here wishing I was in a concrete bunker "hmm, would I be over 130dB if I were?" Not just the listening room but the enclosure room as well, force a lot more through the port instead of mostly lost.
post #87 of 661
Quote:
Originally Posted by MKtheater View Post
OK, did some more measuring.
This is considered +/- 5db from 20-80hz?
post #88 of 661
Thread Starter 
Quote:
Originally Posted by CZ Eddie View Post
This is considered +/- 5db from 20-80hz?
The top sweep is +/- 5 db's from 11-80hz.
post #89 of 661
Quote:
Originally Posted by kryptonitewhite View Post
I just KNEW you were gonna say that! Ya, you have me sitting here wishing I was in a concrete bunker "hmm, would I be over 130dB if I were?" Not just the listening room but the enclosure room as well, force a lot more through the port instead of mostly lost.
Great thread, those things are monsters.

Does anyone on here have an all concrete room (including ceiling)? Next house to do list.
post #90 of 661
This looks insane. My current room is 20x26. 3 of the 4 walls have concrete behind them. My only issue is my ceilings, there is nothing covering them its just the frame. I am considering covering it with drywall but its a ton of work and more money than I wanted to spend. Will I see any gain from putting one up? I plan on having 2 thts in the front corners and the f20s in the rear corners.
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