Novice stereo subs project with stereo amp.

[planet10]

I'd take the little fillet out, and it should be good to go... but it would be more faithful to the original if mutated so that you had something like the attched

dave

 

[PJeff]

Great! Thank's David,
I'll modify it as you're suggesting...
Can you please tell me a bit more about the Shadow enclosure principle... How would you call it?... Ported+Horn?... What's the advantages of that enclosure with the TRIO12 over a ported box, a tapped horn or a transmission line? What's your experience with it?

Cheers
PJeff

 

[planet10]

It is called a BVR -- Big Vent Reflex. The addition of the high aspect slot vent adds some R to the vent to help combat the drift in tuning inherent in a no-flat T/S curve.

dave

 

[PJeff]

It is called a BVR -- Big Vent Reflex. The addition of the high aspect slot vent adds some R to the vent to help combat the drift in tuning inherent in a no-flat T/S curve.

dave

Humm!!! Let's see..... Does that mean the frequency responce curve of just the reflex part isn't flat and the ''high aspect slot vent''(horn part) helps flattening it? (Sorry but I'm very novice at this.).
I've tried modeling just the reflex part with the Trio12 driver in WinISD and I get a box tuning frequency of 23.2Hz, a RED value of ''Vent mach'' which is 0.17, a frequency curve with a top spl value of +1.4dB at 56.5Hz and a -3dB at 31Hz.
-I'm at my very first experience with WinISD so am I correct with those values?
-Should I worry with the RED ''Vent mach'' value?
-Can I hope for a flatter response and a better lower extension with the added ''high aspect slot vent'' and the room gain.

I would like to have a better understanding and a better idea what to expect from this Trio12/Shadow design.

PJeff

 

[planet10]

WinISD is incapable of modeling this. Actually i don't think anything can ... maybe Akabak.

One uses the tools at his disposal to model something, knowing, broadly what will happen when it is morphed into what is intended. These are Scott's designs, he has a range of tools, some he has written himself, and a whack of experience.

The closest you'll find to a general tutorial is the thread on Replikons (not to be confused with decepticons)

dave

 

[PJeff]

WinISD is incapable of modeling this. Actually i don't think anything can ... maybe Akabak.

One uses the tools at his disposal to model something, knowing, broadly what will happen when it is morphed into what is intended. These are Scott's designs, he has a range of tools, some he has written himself, and a whack of experience.

The closest you'll find to a general tutorial is the thread on Replikons (not to be confused with decepticons)

dave

Thank's Dave,
I found the thread and will have a look at it when I'll have a few minutes to focus on this..

PJeff

 

[PJeff]

I would like to have a better understanding and a better idea what to expect from this Trio12/Shadow design.

Dave,
Could you please elaborate on what's your experience with the shadow enclosure with the Trio12 driver for me to have a better understanding of what I would be getting regarding performance?

To anyone interested,
To get the best performance for music reproduction, do you recommend a preferable firing position for the driver and the mouth in relation with the monitors? Right now, my variation is a front firing driver with a rear mouth but that's a first idea we can elaborate from... In my room, my actual monitors(9''Wx12''Dx16''H) have about 30'' free space from the front wall and 36'' from the side walls. What's your opinions?

PJeff

 

[planet10]

Could you please elaborate on what's your experience with the shadow enclosure with the Trio12 driver for me to have a better understanding of what I would be getting regarding performance?

I have no direct experience, so no. It should give good, deep, controlled bass. On course room positioning is critical. Usually not the same place as the mains.

Floyd Toole and Sean Olive have a number of downloadable papers on the subject, but even all of those don't cover things as well as Floyd's book.

dave

 

[PJeff]

Do you think I would get any advantage going with a front or side firing Mouth instead of a rear firing one?

PJeff

 

[planet10]

Bass is omnidirectional. as long as a wall does not obscure the driver or opening you be fine. For max versalility make a mirror imaged pair with side firing vents.

dave

 

[PJeff]

First, I'm thinking that a front mouth might be a little more flexible for positioning experimentation allowing the cabinet to be closer to the front wall ''if necessary'' cause it's of course not my preferred location.

Secondly, Last night I did a bunch of simulation with different drivers(in WinISD) and the Trio12 looks excellent, quite versatile and great value versus drivers like Dayton RSS and Titanic and several Eminence drivers for exemple. So, so far, I'm leaning towards the Trio12 to be my driver of choice...( impressive lower extension in a vented 115L box tuned to 21Hz) but... I'm a little unsure about the enclosure. The Shadow enclosure seams a little different in design from the Replikon so I do not have much to refer to to figure out how the Shadow enclosure will perform... Lower frequencies extension? Dynamics? Accuracy? And even though I am confident in it's doability, it's not the simplest enclosure for so little info on how it will sound... and lets not forget that I want to build a couple of them.

Any opinion/suggestion to help me ?

PJeff

 

[PJeff]

First, I'm thinking that a front mouth might be a little more flexible for positioning experimentation allowing the cabinet to be closer to the front wall ''if necessary'' cause it's of course not my preferred location.

Secondly, ...

Any opinion/suggestion to help me ?

PJeff

Here's a pic to illustrate the first point of my previous post.

 

[planet10]

You get even more versatility by doing mirror pairs of the 1st one with side firing mouths.

dave

 

[PJeff]

You get even more versatility by doing mirror pairs of the 1st one with side firing mouths.

dave

I will play around with that idea... thanks!

PJeff

 

[PJeff]

I have no direct experience, so no. It should give good, deep, controlled bass. On course room positioning is critical. Usually not the same place as the mains.

Floyd Toole and Sean Olive have a number of downloadable papers on the subject, but even all of those don't cover things as well as Floyd's book.

dave

As a newbie, I think I just need a little confidence boost with this project here... I'm asking you cause you guys have a lot more hands on experience than I do.

So, let's start with the basics... do you think the Trio12 is a good value driver choice for what I want to do in it's price range(139$)?
(Reckhorn F-1 stereo to a 100w/8ohm integrated amp driving a couple subs, seeking clear, good transient sound to complement stereo monitors, lower extension 30Hz flat, at least 95dB, for music+movies)

PJeff

 

[planet10]

yes, yes, yes... go for it.

dave

 

[tb46]

Simulating PJeff's Shadow variant 1.2

Hi PJeff,

This may be as good a project as any for getting into Hornresp . Here is one way this can be simulated in Hornresp. Basically as a back-loaded horn with a large throat chamber, a short coupling section to the straight duct, and a second coupler to the port horn. After hitting calculate you must use the combined response button to see the in-room total, the path length is probably in the neighbourhood of about minus 45cm. You can also use the sliders in the Horn Loudspeaker Wizard to modify the individual dimensions.

Regards,

 

[PJeff]

yes, yes, yes... go for it.

dave

Thank you for the words of encouragement Dave... my mind is set on the Trio12... just need to decide on the enclose now...

PJeff

 

[PJeff]

Hi PJeff,

This may be as good a project as any for getting into Hornresp . Here is one way this can be simulated in Hornresp. Basically as a back-loaded horn with a large throat chamber, a short coupling section to the straight duct, and a second coupler to the port horn. After hitting calculate you must use the combined response button to see the in-room total, the path length is probably in the neighbourhood of about minus 45cm. You can also use the sliders in the Horn Loudspeaker Wizard to modify the individual dimensions.

Regards,

Thank you for this tb46,
I've played around with that and what i've noticed, with my limited knowledge, is that the extension is somewhat limited in the Shadow enclosure compared to something like a ported 119L box tuned to 20.6Hz(see attachments). Do you see any advantage the Shadow has in other areas? Dave any thoughts?

I need help here!!!!

How can I get the cleanest reproduction and best transient with a decent lower extension with a stereo installation(two seperate enclosures) with the Trio12(flat to 30Hz in room if possible) without much calibration other than placement?

PJeff

 

[PJeff]

Thank you for this tb46,
I've played around with that and what i've noticed, with my limited knowledge, is that the extension is somewhat limited in the Shadow enclosure compared to something like a ported 119L box tuned to 20.6Hz(see attachments). Do you see any advantage the Shadow has in other areas? Dave any thoughts?

I need help here!!!!

How can I get the cleanest reproduction and best transient with a decent lower extension with a stereo installation(two seperate enclosures) with the Trio12(flat to 30Hz in room if possible) without much calibration other than placement?

PJeff

Sorry, forgot the attachments... Here they are...