Sonosub + RL-p15 - Design confirmation - Page 13 - AVS Forum
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post #361 of 401 Old 03-16-2007, 01:34 AM
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Oh sorry, I guess I missed the back thing. Definitely take it easy then. Hope you feel better soon.

That last graph with the port/driver graphs averaged, looks ok to me.
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post #362 of 401 Old 03-16-2007, 01:50 AM - Thread Starter
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Quote:
Originally Posted by Willd View Post

Oh sorry, I guess I missed the back thing. Definitely take it easy then. Hope you feel better soon.

Haven't mentioned it, so how could you have known? I've been trhough it before, so I know it's going to be ok again (eventually ).

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Originally Posted by Willd View Post

That last graph with the port/driver graphs averaged, looks ok to me.

That's good to know

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #363 of 401 Old 03-16-2007, 01:58 AM
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Yeah, when you consider the relative inaccuracies of the measurements (not your fault) and the effects of the room, it looks like a good FR.
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post #364 of 401 Old 03-16-2007, 02:58 AM - Thread Starter
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Quote:
Originally Posted by Willd View Post

Yeah, when you consider the relative inaccuracies of the measurements (not your fault) and the effects of the room, it looks like a good FR.




Now that the snow is finally gone, I'll soon enough take the sub outside. Then we can get some real measurements.

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #365 of 401 Old 03-16-2007, 06:42 AM
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Rune,

You can't get an accurate measurement with the RS meter, IMO. You also can't average the port/driver measurement curves to get an approximation of the overall FR.

At least, one would hope that your port graph isn't accurate, or that it won't have as much influence on the overall response as the avreaged graph shows.

The trouble with such a big sub is that an outdoors measurement is the only way you'll be able to see what's happening, anechoically, and I even doubt that a 2 meter distance will be enough at that.

So far, no one has done an accurate ground plane measurement of the alignment you've built, so it would be very interesting to see one.

Hope you're feeling well soon...then git yer butt outside and measure those things!

Bosso
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post #366 of 401 Old 03-16-2007, 07:16 AM - Thread Starter
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Quote:
Originally Posted by bossobass View Post

Rune,

You can't get an accurate measurement with the RS meter, IMO. You also can't average the port/driver measurement curves to get an approximation of the overall FR.

Do you say so? Well I'm totally green in this measurement game, so I'm just sucking up all tips/info I can get. I imagined that the total output from a sub was driver+port, but there's obviously not as easy as that.

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Originally Posted by bossobass View Post

At least, one would hope that your port graph isn't accurate, or that it won't have as much influence on the overall response as the avreaged graph shows.

Yes, it is maybe a little odd (too little pronounced at the tuning frequency?)...

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Originally Posted by bossobass View Post

The trouble with such a big sub is that an outdoors measurement is the only way you'll be able to see what's happening, anechoically, and I even doubt that a 2 meter distance will be enough at that.

So far, no one has done an accurate ground plane measurement of the alignment you've built, so it would be very interesting to see one.

Here I go again... I'm not sure what a "ground plane measurement" is...

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Originally Posted by bossobass View Post

Hope you're feeling well soon...then git yer butt outside and measure those things!

Bosso

My back is feeling better already!

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #367 of 401 Old 03-16-2007, 07:21 AM
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Hey Rune,

Grounplane measurements are taken with the mic at gound level at whatever distance is required, 1M or 2M typically. You can check the AV Talk subwoofer tests for some good picutres of this technique....

http://www.subwoofertests.com/testresults.html

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post #368 of 401 Old 03-16-2007, 02:57 PM
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Considering that these measurements were taken in doors, that summed response looks pretty close to what it should. The sub is definitely operating correctly, now you just have to worry about proper placement and perhaps some EQ to get your at the seat response flat when your room is finished and everything is set up.
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post #369 of 401 Old 03-16-2007, 03:07 PM - Thread Starter
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Originally Posted by SteveCallas View Post

Considering that these measurements were taken in doors, that summed response looks pretty close to what it should. The sub is definitely operating correctly, now you just have to worry about proper placement and perhaps some EQ to get your at the seat response flat when your room is finished and everything is set up.

I'm really glad to hear that, Steve!

Too bad I've already blown my EP2500 The clip light for channel 1 is constantly on and from output 1 there's only distorted garbage.

If it hadn't been for my fan mod I could have gotten it replaced, but of course now the warranty is non-existent... well, well - it's only money! Better the amp thatn my subs, I say

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #370 of 401 Old 03-16-2007, 03:15 PM
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Bummer! I have not heard of many failures, but I guess they do happen.

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post #371 of 401 Old 03-17-2007, 02:47 AM - Thread Starter
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Quote:
Originally Posted by jpmst3 View Post

Hey Rune,

Grounplane measurements are taken with the mic at gound level at whatever distance is required, 1M or 2M typically. You can check the AV Talk subwoofer tests for some good picutres of this technique....

http://www.subwoofertests.com/testresults.html

OK. Thanks for the info

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #372 of 401 Old 03-17-2007, 05:50 AM
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Quote:


Too bad I've already blown my EP2500 The clip light for channel 1 is constantly on and from output 1 there's only distorted garbage.

Well that ain't no good! Sorry about that

Klipsch RB-75
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On-going SW management class
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post #373 of 401 Old 03-18-2007, 08:23 AM - Thread Starter
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empty

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #374 of 401 Old 03-18-2007, 08:24 AM - Thread Starter
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Quote:
Originally Posted by jpmst3 View Post

Hey Rune,

Grounplane measurements are taken with the mic at gound level at whatever distance is required, 1M or 2M typically. You can check the AV Talk subwoofer tests for some good picutres of this technique....

http://www.subwoofertests.com/testresults.html

I forgot to mention it: Why measure at ground level? I usually have my ears a little higher above ground than that...

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #375 of 401 Old 03-18-2007, 08:41 AM
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Quote:
Originally Posted by RuneW View Post

I forgot to mention it: Why measure at ground level? I usually have my ears a little higher above ground than that...

When the mic is at ground level, you don't get an instant reflection from the ground Quite brilliant when you think about it
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post #376 of 401 Old 03-18-2007, 08:43 AM
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Quote:
Originally Posted by RuneW View Post

I forgot to mention it: Why measure at ground level? I usually have my ears a little higher above ground than that...

Rune, here is what I got from AV Talk as an explanation:

"Of course, being a hard surface, there are reflections from the ground itself but because the sub and microphone are placed directly on the ground the difference in path lengths is minimised so the phase effect is small. In fact the microphone 'hears' two versions of the sub, the real one and its virtual image reflected in the ground which is why a ground plane measurement made at 2m is 6dB higher than it would be if you measured at 2m with the sub somehow floating in free space. "

I am not sure if that helps, but I often wondered that myself.

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post #377 of 401 Old 03-18-2007, 09:30 AM
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> the microphone 'hears' two versions of the sub, the real one and its virtual image reflected in the ground

Sorry if I intruded your thread RuneW!

Do you think a conical defector attached would rid of the "reflected" sound? I posted this question before, but no replies...

http://www.avsforum.com/avs-vb/showt...&&#post8003152

Inspired by many here (many thanks to Steve) I'll start to build a sono here soon, my TC-2000 arrived Thursday (3-15). It will have the added conical deflector on the bottom & top (which raises the height to about 78"!
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post #378 of 401 Old 03-18-2007, 09:44 AM - Thread Starter
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Quote:
Originally Posted by layertone View Post

> the microphone 'hears' two versions of the sub, the real one and its virtual image reflected in the ground

Sorry if I intruded your thread RuneW!

Do you think a conical defector attached would rid of the "reflected" sound? I posted this question before, but no replies...

http://www.avsforum.com/avs-vb/showt...&&#post8003152

Inspired by many here (many thanks to Steve) I'll start to build a sono here soon, my TC-2000 arrived Thursday (3-15). It will have the added conical deflector on the bottom & top (which raises the height to about 78"!

Do you have a drawing of these conical deflectors attached to the sub?

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #379 of 401 Old 03-18-2007, 10:10 AM
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I'm actually working on the drawing right now. To keep things simple & prototype, i'll just do a straight 45 angle...

Duevels actually have the "deflector" turned with Plywood

http://www.cd-konzert.de/details/EBLSchnitt.shtml


This was a previous PM...

I'm still thinking about doing the conical deflector on the base just like the Duevel Jupiter...

http://www.6moons.com/audioreviews/duevel3/jupiter.html


Really wanted to impliment this deflector based on what I learned from building the Austin II horns; credit goes to Ron Clarke, the designer as he states here:

"The deflector is a necessary as it prevents the wave front from being sent back to the mouth as well as providing the final wave expansion which allows a more spherical front to develop.
The SB will allow a lower diffraction wave launch as well as providing frequency support from the roll off of the horn action.

Combing both will give a flatter FR curve with a lower Fc.

ron"
Link:
http://http://www.diyaudio.com/forum...77#post1153777

I built the black Austins horns here shown with the rear deflector behind the mouth of the horn

http://www.frugal-horn.com/ronhorns.html
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post #380 of 401 Old 03-18-2007, 11:44 AM - Thread Starter
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Originally Posted by layertone View Post

I'm actually working on the drawing right now. To keep things simple & prototype, i'll just do a straight 45 angle...

I started a separate thread about "sonosub bottom cone". As you can read from that thread, the avs forum users weren't overly enthusiastic about the idea... (but I still think that a bottom cone feels right )

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #381 of 401 Old 03-18-2007, 11:51 AM
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Hmmm. That is interesting. I wish someone had some data to support or denounce the use of a cone. It sounds logical (pun intended) but might not translate into practicallity.

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post #382 of 401 Old 03-18-2007, 11:53 AM
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Quote:
Originally Posted by RuneW View Post

I started a separate thread about "sonosub bottom cone". As you can read from that thread, the avs forum users weren't overly enthusiastic about the idea... (but I still think that a bottom cone feels right )

Wow, we have the same idea! I think it would have benefits. Imagine if you were to shine a flashlight directly perpendicular to a mirror - the light would just reflect right back (distortion). If the mirror was folded, the light would dispurse away.

You're right. Forum users are not enthusiastic about it, so let's start a STORM! I will impliment the bottom cone (maybe on top as well) on my sonosub DARE to be different!

BTW, how are your sonos, any new pictures?
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post #383 of 401 Old 03-18-2007, 11:54 AM - Thread Starter
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Want to see something funny?

A few people were skeptical about my my DIY-port-grille (which was attached to the sub with magnets) - you were right

I was doing some serious break in with 20-64Hz pink noise when this happened:


(klikk på bildet for video)

Too bad I didn't get the fun part, because for a while the grille was suspended 4-6 cm over the port like an UFO. I guess I was playing even louder then...

Guess I'll have to look for some other kind of grille. I'm thinking about replacing the fabric with some kind of black (painted) mosquito net thingie, and screw the damned thing in place instead of using magnets...

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #384 of 401 Old 03-18-2007, 05:00 PM
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Originally Posted by RuneW View Post

Want to see something funny?

A few people were skeptical about my my DIY-port-grille (which was attached to the sub with magnets) - you were right

I was doing some serious break in with 20-64Hz pink noise when this happened:


(klikk på bildet for video)

Too bad I didn't get the fun part, because for a while the grille was suspended 4-6 cm over the port like an UFO. I guess I was playing even louder then...

Guess I'll have to look for some other kind of grille. I'm thinking about replacing the fabric with some kind of black (painted) mosquito net thingie, and screw the damned thing in place instead of using magnets...

Cool picture Rune! At least you know you are movin' some air!

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post #385 of 401 Old 03-23-2007, 04:30 AM - Thread Starter
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After quite some weeks of back problems and general inactivity, I finally managed to finish the twins!

Here's the baseplate mirrors that I've waited for for so long:

(Ø40cm)

Here in place in the recession:


The Sonosub in the usual "cannon-position", while the base plate is screwed on:

(The "cannon-position" is when the sub is gently laid across a whold package of Rockwool with one end higher than the other, so that I can work on it. It's the only way to handle the beast singlehandedly...)

Here with both mirrors in place:

(try to imagine them without the dust & dirt from the basement environment )

Unfortunately there is a gap of about 2-3mm between the mirror and the recession wall. It's quite visible with a strong back light like below, but in normal light conditions (like in the cannon picture above) it looks alright:

(maybe I'll fill the gap with black silicon later on. We'll see...)



And here (after about 5 months of work - between family life and house refurbishing)

The TC-2000 Sonosubs finally finished:



I want to thank all of you that have bothered to follow this thread. Thank you so much for your insight, help and moral support!

-Rune Winsevik,
NORWAY

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #386 of 401 Old 03-23-2007, 05:44 AM
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OUTSTANDING Rune.....they look awesome and you should be proud!

great craftsmanship, excellent attention to detail, and a very good implementation overall. You did a good job, and I enjoyed following this thread in parallel with my own!

did you ever correct the measurements and that nasty dip and rolloff? lets see the measurements of these bad boys next, ok?

welcome to the club
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post #387 of 401 Old 03-23-2007, 06:09 AM - Thread Starter
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Originally Posted by ssabripo View Post

OUTSTANDING Rune.....they look awesome and you should be proud!

great craftsmanship, excellent attention to detail, and a very good implementation overall. You did a good job, and I enjoyed following this thread in parallel with my own!

Thanks! And the same goes to you!

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did you ever correct the measurements and that nasty dip and rolloff? lets see the measurements of these bad boys next, ok?

welcome to the club

That dip was certainly the room. It only snowed a little today ( ), so I'll soon be able to take the twins outdoors. Then I can do some proper measurements.

My sonosub project pictures all in one place (PS! Norwegian text!)
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post #388 of 401 Old 03-23-2007, 06:25 AM
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GOOD JOB Rune!!!!!

Those are some fine examples of sonosubs. Great work!

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post #389 of 401 Old 03-23-2007, 06:38 AM
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Congratulations Rune! Your thread has been a wonderful read. When is your HT room ready?
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post #390 of 401 Old 03-23-2007, 06:49 AM - Thread Starter
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Quote:
Originally Posted by jpmst3 View Post

GOOD JOB Rune!!!!!

Those are some fine examples of sonosubs. Great work!

Thanks

Quote:
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Congratulations Rune! Your thread has been a wonderful read. When is your HT room ready?

Oh boy... If I use 5 months building a pair of subs, how long do you think I'll spend on a complete HT?

Jokes aside - I've got only ONE bathroom to refurbish before the HT project is greenlighted by the authorities (or should I say "authority"...).

We're probably talking of starting this summer. I hope to be ready (sort of) before this winter. Maybe I'll start another build thread for that project...

My sonosub project pictures all in one place (PS! Norwegian text!)
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