Forums - Print Page

Forums
https://www.decware.com/cgi-bin/yabb22/YaBB.pl
SPEAKER FORUMS >> DNA Horn >> The Current R&D I heard at Bob Z's
https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1363172589

Message started by MikeZ@turningpointaudio on 03/13/13 at 12:03:08

Title: The Current R&D I heard at Bob Z's
Post by MikeZ@turningpointaudio on 03/13/13 at 12:03:08

Morning!
I thought I would pop over here and let you know what Bob is up too.
Last Thursday I took a trip over to his shop to visit. He started to talk about his DNA's he had and the driver situation that had been an issue. Then he said, "Well come in and take a seat, listen and tell me what you think." Started with my eyes closed as to not give an opinion before hearing anything. The music of Klaus Badelt came on with a small marching snare in the dead center of the music and I thought well that's nice. Then the roar of timpani come out from behind me, the blast of a trombonist's lips from the right of the room, a french horn crawling up the left side, and all the while the snare drum marching beat sitting where it did in the beginning. Now it got loud, I like it to be dynamic, but all the details were there. The snare never faded, the flutes and clarinets were not depressed by the brass section, and yet all of this sound just filling the room so precise. Like most on these forums I know the lingo, but rarely do I truly get the goose bumps from hearing it delivered.
I think Bob is on to something here.
Mike Z ;)

Title: Re: The Current R&D I heard at Bob Z's
Post by 4krow on 03/13/13 at 22:49:20

Now exactly which drivers is he using now? And what did you think of the bass impact?

Title: Re: The Current R&D I heard at Bob Z's
Post by will on 03/14/13 at 01:01:53

Quote:

the roar of timpani come out from behind me

Holy shit!

Do tell more.

Title: Re: The Current R&D I heard at Bob Z's
Post by Palomino on 04/04/13 at 23:33:51

As a test, Bob relayed the drivers and Xover specs to me and I picked them up for less than $200 delivered from Madisound. It also requires some modifications to the cabinet, but these can easily be done to an already built enclosure.

My impression of this configuration mirrors what Mike has said. Bob is on to something here. I think you get a fuller sound, better (insane) imaging, just as deep or deeper bass and great detail.

The crossover design does require a leap of faith in that the expected frequency response is not flat, but rather it has a dip in the midrange. The theory is that the human ear over-emphasizes this part of the response curve and equalizes the sound to a flat response curve in your head. So if you are a numbers guy and model this out and can't live with that dip, then this is not for you.

Bob relayed all this to me prior to the test and I decided to trust him and his ears versus what a simulation program would tell me.

I like the W5 driver and have used it in 3 different cabinets so far, but now I have Zygi-fied my speakers and won't be looking back.

You could PM Bob or with his permission I can relay the secret sauce.

Title: Re: The Current R&D I heard at Bob Z's
Post by 4krow on 04/05/13 at 03:42:42

I got the plans for the original cabinet, and I don't want to buy drivers twice, and modify the cabinet. I am hoping that the 'secret sauce' will be given now that the original drivers are no longer available.

Title: Re: The Current R&D I heard at Bob Z's
Post by Palomino on 04/05/13 at 04:33:52

I'm pretty sure Bob will share. He seems very open on the DIY stuff. It's just not my sauce so I'm not sure I have to right to share it.

I just saw Steve's thread on the replacement DNA driver. At that price, I'd be tempted to try it as well. Both options need a tweeter. And it looks like both woofer options will fit the W5 hole.

For the test, I took out the W5, wired up the new woofer and coil to the internal wiring, wired up the tweeter and cap to the binding posts and actually taped the tweeter just above the woofer with painters tape. Then I put in the material to reduce the size of the compression chamber and stuck the new woofer in. It did require I drill new holes.

I have been running like this for a couple weeks during the evaluation. When I get time, I will drill a new hole for the tweeter and rewire it to the internal wiring and be done.

I just finished three hours of listening. Blues mostly with a heavy bass line. The bass was superb.

Title: Re: The Current R&D I heard at Bob Z's
Post by Palomino on 04/05/13 at 04:42:16

Also, Mike, if you know what disc that track came off of, I'd like to get it and see if I get the same kind of imaging. I don't recall which disc I was listening to, but I also had a "sound from behind me experience" with these speakers.

Title: Re: The Current R&D I heard at Bob Z's
Post by Palomino on 04/05/13 at 17:02:25

I PM'd Bob and he said let er rip...

Here are the instructions I worked from:

The drivers are SB acoustics...sb15nrxc30-4
Vifa...xt25sc90
Coils are 0.1 16 gauge sidewinder
Caps are 4.7 I would start with the PX4.7 Clarity Cap (Personally I like, for a cheap cap, the Jenzens from Parts Express there next up from the cheapest. If you like what you hear and they work, I would then proceed to the Mundorf Supreme, not worth while unless you like the system as a whole.

Note: Cap is on the tweeter, coil on the woofer. The tweeter is wired out of phase. Hole for the W5 is 122mm and the hole for the SB is 123mm (or vice versa) so it will fit if you have already made the hole in your baffle. I had to re-drill the mounting holes because I couldn't get the new driver to line up with the W5 holes.

Go to your local Home Depot/ Lowes and buy some fiber board (Cylotex) like they use for house wrap. It's black on one side and natural on the other side. This was what I used, from the outside to cut my inclosed volume down to almost half.

Note: I cut two peices of material slightly wider than the chamber width and put them in through the existing hole, then wedged them against each side to form an upside down V and pushed them down into place. Then I taped the seams. You want the new floor of the chamber to be just below the driver.

For the tweeter hole, Bob suggested 1/2" distance between the flange of the tweeter and the flange of the woofer.

If you are interested in the theory behind the crossover, the white paper is available from this guy: http://howtodesignaspeaker.com/

BTW, this theory was dissed by the regulars on at least one of the other forums. Coincidently, the same crew that dissed the DNA. That thread got me interested in the DNA and lead me to Decware. I can't thank them enough.