New Approach for an Outline from a DIY Subwoofer - Precision Devices PD2150 inside

[tiefbassuebertr]

Here a bass transmission project, equipped with PD2150, mounted on a closed cabinet of 1800 liters (main part of cabinet is in the attic) - together with the vintage loudspeakers DQ10 (DQ-10) from Dahlquist - go to
Dahlquist DQ-10 flashback
Power amp for the PD2150 is the already present power amp Quad 405, for the Dahlquist is in use the Italian Brand "AES", model TWO and the preamp is the Quad 33 - I think. Compact Disc Player is the Denon DCD 1520 - go to
http://lh5.ggpht.com/-w43d5UwMN3A/Rw...nonDCD1520.jpg

[ßart West-VL.]

You don't often see that kind of subs. Very nice!
Any comment on the SQ?

[1audiohack]

My first question is how in the hell did you get them up there?!? I have a new pair of them that I am still moving around and working to integrate into my main system and they are heavy!!! I don't have a firm opinion of mine yet but they are authoritative for sure.

How do you like yours?

[epa]

0,5 space indeed

[tiefbassuebertr]

Originally Posted by 1audiohack

My first question is how in the hell did you get them up there?!? I have a new pair of them that I am still moving around and working to integrate into my main system and they are heavy!!! I don't have a firm opinion of mine yet but they are authoritative for sure.
How do you like yours?

four guys was helping for getting up there. Please note: this isn't my own audio system (go to my website for more examples).
And in this attachement an other sub woofer project with two of this transducers in a common chamber.

Originally Posted by ßart West-VL.

You don't often see that kind of subs. Very nice!
Any comment on the SQ?

What means the abbreviation "SQ" ?

[m R g S r]

^wow your wife must love you! lol

thats awesome!


and SQ is Sound Quality

[tiefbassuebertr]

Originally Posted by m R g S r

^wow your wife must love you! lol
thats awesome!
and SQ is Sound Quality

.... and must love music (you mean the wife of the user).
By post #1 about
Ultimate Solution for an User with already present "InWall" Subwoofer:ESL or dynamicL
(image number 1) you will find a solution, developed/decided by the wife of it's user.

[kipman725]

wow I had a look at your site; very impressive subwoofers!

[fireworks]

Any measurements, especially on the one in the attic ?
How low can they go ?

[tiefbassuebertr]

Originally Posted by fireworks

Any measurements, especially on the one in the attic ?
How low can they go ?

Because I get still similar curvatures by all projects in this sizes (nearly perfect bandpass character) I don't save the acoustical measurement results in the last years.
The two cascaded subwoofer high-pass filter (subsonic) of the actice crossover unit (12db/oct) is adjustable between 10Hz and 30Hz (also adjustable between Tschebyscheff and Bessel), and the follow three cascaded 12 db Sallen-Key lowpass units are independend adjustable between 30Hz and 140 Hz.
This condition allows it, to get in most cases the wanted acoustical bandpass character.
By the system from post #1 the -6db cutoff frequencies are 18 Hz and 90Hz (acoustical slope at each roll-off end: 36db/oct).
When the acoustic environment is problematic (e. g. unwanted interfering peaks) an additional notch filter is necessary.
But until now I don't need such a thing.
BTW - I use since approximately 1993 until now the acoustical measuring system DAAS32NT from
http://www.adm-engineering.homepage.t-online.de/
Very important is the perfect designing of the high pass filter for the present loudspeakers (mostly passive, basicly two resistors, an inductor and 1-2 MKP capacitors). With help of my universal high pass filter and the CAD software "Bassyst" for me an easy task by all loudspeaker models, even large versions.
After doing this, you only need yet the mirror-image low-pass filter curvature adjust