Danley DTS20 anyone build one?

[dave 111]

Anyone build a clone of the DTS20 or hear an actual one?

It seems like with a little space and some wood this would be an economical way to get some great, efficient, bass from 20-100.

Does anyone know what driver would work in it?

Reason for asking:
I have a 25x33 long listening room with 10 foot ceilings.
Upfront is an unfinished niche for an entertainment center that currently houses two 15's infinite baffle and my favorite full range drivers in a box pointed at my head. They are sealed , play down to about 100.

I'm going to build out the niche and when I do I'm planning on going to 4 15's or 8 12's with more excursion. The current 15's aren't ideal, they're PRV so they have QTS of .62 but only about 6mm's of excursion. Still the most engaging best bass I've ever had domestically. The 1611's are going in the wall, again, pointed at my head.

So bass array or DTS20? Maybe something else but I'm most interested in these two options right now.

Factor that I am decent at math but computer challenged in your responses. My system consists of a Denon audio video receiver with a Dayton 250 plate amp ran to my subs. I know I will need a new amp for the new 15's if I go that route.

Thx

 

[dave 111]

Also, the listening position is 12" away give or take a little. If I do the horizontal bass array do you think it will dump more of the bass right in my lap? I get a decent amount now.

My concern is for music only not theater.

I've heard horns need some space to develop the bass (I assume the DTS20 is some kind of horn).

 

[kipman725]

I haven't heard one. I have built similar tapped horns before (simpler design only one fold - no stub). The mouth is very small with respect to the wavelengths that the horn produces so you would not expect behaviour in a room to be any different to a direct radiator. A lot of rules of thumb that would apply to a traditional front loaded horn speaker do not carry over to tapped horns.
http://www.danleysoundlabs.com/wp-content/uploads/2012/01/The-Tapped-Horn.pdf

My personal experience is that to get even bass throughout a room you need multiple subs and equalisation to reduce the effect of the modal behaviour of a room. Before you build new stuff you should look at how the response of what you have varies through your room:
Room Measurement Tutorial for Dummies Part 1 | Audio Science Review (ASR) Forum
In terms of driver size 18" usually gives you the most output per unit money if you can cope with the cab size (assuming simple box designs).

 

[dave 111]

If I go through the trouble of building the monster I'm gonna build two!
It would be much easier to just throw 4-18's in the wall

 

[Brian Steele]

The mouth is very small with respect to the wavelengths that the horn produces

THs are not really "horns". Like most bass "horns", they're more like 1/4 wave resonators, e.g. TLs.

 

[TBTL]

Here are some more 12" tapped horns: Lab12 - Tapped Horn -

 

[kipman725]

If I go through the trouble of building the monster I'm gonna build two!
It would be much easier to just throw 4-18's in the wall

If on or in wall mounting is possible and your room has the correct dimensions you might consider a double bass array:
Double bass array - Wikipedia

I have also seen this work without the rear array and instead using a (very large) acoustic absorber on the rear wall.

 

[dave 111]

The opposite side has kitchen cabinets on an exterior wall. Build a soffit and vent into the crawl space I guess but hard to get waf on that I think. I'm happy she lets me build ugly speakers that sound good though.

 

[dave 111]

Would one of you be kind enough to calculate for me what four of these Image Dynamic 12's could do infinite baffle. Woofers etc has them and strangely though a car sub 8 ohms. And only $89

Qts .56
Fs. 23
Vas 131
85 db and 16 mms of excursion

Edit: 85.8 db to be precise and rms of 175 with peak of 350

 

[kipman725]

the important parameters are the xmax and cone diameter for IB, it doesn't take much power to hit xmax:
Piston Excursion calculator

to get decent bass low in frequency your looking at many larger woofers

 

[GM]

Anyone build a clone of the DTS20 or hear an actual one?

So bass array or DTS20? Maybe something else but I'm most interested in these two options right now.

Auditioned a pair as part of a huge HT system up at DSL /Gainesville, Ga. back when they were finishing the Matterhorn.

The performance was small scale IMAX quality/intensity, nearest to live I've ever experienced with a recording [don't recall which Diana Krall BD] and especially the thunderstorm in Spider-man 3?, but then the room was so 'live' it's not surprising, plus was connected to mass quantities of top end pro electronics, so about all I can say is that short of maybe the best pipe organ symphonies that requires its big brother [DTS10], can't imagine needing more than a pair WRT peak SPL for a typical analog/digital music system once dialed in with DSP/TD.

Frankly, if going to DIY a TH and got the space, a single DTS10 goes lower, louder, then use smaller/cheaper subs spread around the room for modes 'fill' per Dr. Geddes as my answer to 'TH Vs [cheap] sealed array' : Danley DTS-10 "Super Spud" DIY kit - Page 346 - AVS Forum | Home Theater Discussions And Reviews

Lots of placement, fine tuning, upgraded woofers, etc., info even if you still prefer a ~DTS20 clone.

GM

 

[dave 111]

Thank you.
If I did it right it looks like 110db at 20hz.
That seems like a lot

 

[GM]

Image Dynamic 12

Link? Google only returns $$ high end subwoofers.

GM

 

[dave 111]

CTX128 - Image Dynamics 12" CTX 8 ohm Subwoofer

 

[GM]

Thanks! I've noticed quite a change recently in what Google Search returns and not for the better!

Regardless, HR IB sim [10x Vas = ~1310 L] @ 20 Hz/2 pi = ~100 dB/m/20 W/16 mm. ~110 dB/m would be hard into a corner's apex to get max room boundary loading [0.5 pi] with ~105 dB/m/1 pi.

GM

edit: [4] subs in series-parallel = ~110 dB/m/80 W/20 Hz.

 

[dave 111]

Not too sure what all that means.
I will say doing a dts10 sounds like a cool idea and the output looks insane. Biggest reservation is I'm not proficient at dsp or crossovers. I've been relying on full range drivers and a sub amp. It's easy to plug something in and turn a few dials to dial in the bass.

Could I run the dts10 on a sub amp even though it is a 12 db roll off I think? I could do what you said and utilize 2 more subs on another one. The dts works well up to 70 right?

When I started the thread I was unaware of the "special" requirements of the Danley beasts.

 

[GM]

Also, the listening position is 12" away give or take a little. If I do the horizontal bass array do you think it will dump more of the bass right in my lap? I get a decent amount now.

My concern is for music only not theater.

I've heard horns need some space to develop the bass (I assume the DTS20 is some kind of horn).

Missed this...........

Yeah, even a TH [6th order BP] has bit of directivity due to the long expanding duct/vent, so would need to sit back some to get the full impact.

Need to consider the size of the WLs involved. Consider an 80 Hz wavelength is ~169" long with a ~54" diameter, growing exponentially larger with decreasing frequency, so at ~12" away, then as long as it's a sub woofer [<80 Hz] it doesn't much matter where it is vertically other than for room boundary loading purposes.

GM

 

[dave 111]

That should be 12' away. Typing error