V2 Update - When It All Comes Together (Updated 4/21/2011)

Tyson · « **Reply #40 on:** 3 Mar 2011, 05:17 pm »

Quote from: rajacat on 2 Mar 2011, 06:30 am

When you get it right have you considered taking the settings and building a regular passive crossover again? Does the DCX extract a price i.e. a slight negative impact on sound quality when compared to an optimized passive crossover.

It certainly seems that an active crossover is a tweakers dream. Let's say you change the position of a large object such as a couch, you can then go to the DCX and make an adjustment to put things back into balance.

Maybe those last little adjustments compensate for your individual hearing preferences brought about by the shape of your ears, compensation for hearing loss in certain frequencies, etc. Actually ears are like little horns that take in the sound and no two are alike. The last adjustments make the FR flat subjectively whereas
the DCX does it objectively.
-Roy

The DCX even lets you control each speaker individually. Let's say you have one speaker in a corner, and the other speaker in an open area (such as in my L-shaped living/dining area). One speaker will load the room with a lot more bass than the other, due to corner loading. With the DCX you can EQ each speaker independently of the other, so you get the precise settings needed for each acoustic space it sits in. You simply cannot do that with a passive crossover.

You can also individually control phase and delay for every driver individually. Some recordings are recorded out of phase, so being able to change phase settings on the fly can be very useful. You can even save these different settings in the DCX for instant recall based on need/whim. Same with EQ and other things that affect tonal balance, all can be saved individually.

It is, indeed, a tweakers dream. On the other hand, you can simply dial in what you feel are "optimal" parameters and simply set-and-forget it, like you would with a passive crossover, it's completely up to you....

jtwrace · « **Reply #41 on:** 3 Mar 2011, 06:17 pm »

Quote from: Tyson on 3 Mar 2011, 05:17 pm

You can also individually control phase and delay

It's great isn't it!? My two rear subs are different distances from me so I've got them dialed in perfectly with delay. Works Awesome!

rajacat · « **Reply #42 on:** 3 Mar 2011, 06:28 pm »

Soon I will be building some speakers using a OSWG and I'll probably go with the active option. I'll probably use the Mini DSP @ $125 would be not that much more expensive then using and experimenting with a passive crossover.

-Roy

Tyson · « **Reply #43 on:** 3 Apr 2011, 08:22 pm »

Learned a few more interesting lessons with the V2's in active mode, and updated the first post of this thread with details in red.

rajacat · « **Reply #44 on:** 3 Apr 2011, 09:17 pm »

Quote from: Tyson on 3 Apr 2011, 08:22 pm

Learned a few more interesting lessons with the V2's in active mode, and updated the first post of this thread with details in red.

Thanks for the update.

-Roy

Tyson · « **Reply #45 on:** 4 Apr 2011, 08:45 pm »

You're welcome - I also cleaned up the first post a bit so it's more coherent to read through it from beginning to end.

JohnR · « **Reply #46 on:** 5 Apr 2011, 02:55 am »

Great! Very interesting to read your findings

Quote from: Tyson on 28 Feb 2011, 07:44 am

The lack of consistency of radiating patterns between the mids and tweets was a far bigger deal than the acoustics of my room. Or, rather, the difference in radiating patterns seemed to make my room problems worse!

I'm wondering then - what are your thoughts on the need for (or lack of) acoustic treatment with the speaker as it is currently?

Quote

Also, if you are using LR48 crossover slopes, you must invert the output of the tweeter or you will get a deep null at the crossover point.

Are you sure about this? As I understand it the outputs should be in phase.

Thanks

Tyson · « **Reply #47 on:** 5 Apr 2011, 04:02 am »

For the lows, the V2's don't need much treatment, OB bass is pretty good at dealing with room modes effectively. For the mids/highs, there's even more room interaction than with a box speaker. There are gains, of course (soundstage depth), and challenges (wraparound cancellations and re-inforcements). Overall, OB probably makes room treatment even more critical in the mids/highs, but alas I am stuck with no ability to do any treatments....

On the other hand, I have come to believe that coax drivers (when done well as in the V2's), are an inherently superior solution to physically separated mids/highs that most speakers employ.

Dunno what to say about the LR48 phase issues, the measurements are pretty clear. I did them at 6 inches, 1 foot, and 2 feet, and the result was always the same.

Tyson · « **Reply #48 on:** 9 Apr 2011, 03:21 am »

Today has been very interesting. I generally like shallow slopes better than steep slopes, they sound more natural to me. And so it was with the V2's, playing around with the crossovers. But the problem is that I could never get them to sound completely natural in the mids with the shallow slope. I thought it might be some artifact of running OB speakers with no room treatment behind them.

But, today my wife and daughter left for several hours to run errands, so I moved all the furniture out of my living/dining room and did some elevated measurements of the V2's at 1 meter. Very interesting - I found out that the tweeter measures the same as my previous attempts (non elevated), but the midrange does not. With the mids I now see a sharp drop at 1.3khz, and then a nasty, nasty peak at 3.5khz and another at 4.5khz.

So I set my crossover to Butterworth 1st order, and moved my crossover point to 1.2khz. Next I notch filtered out the 3.5khz and 4.5khz peaks on the midrange driver. Ahhhh, MUCH better!! Now I'm getting that more musical overall sound that low order crossovers allow, and also avoiding the hollow/scratchy character that the midrange driver peaks were introducing.

It's a PITA to move everything to get a decent measurement (quasi-anechoic), but its worth it!

cleestedwood · « **Reply #49 on:** 9 Apr 2011, 03:26 pm »

Quote from: Danny on 28 Feb 2011, 08:51 pm

Funny, the passive network is asymmetrical too.

That's true.

Interestingly though, I do have some colleges working on some full digital crossovers to be used on a commercial speaker that is in the works. I can't really go into the details of it, but we are going to use the Super-V for concept testing and development work. It will basically do what the DEQX system will but with an I2S input to a much higher quality DAC and analog output stage. Nothing is currently available like it.

My issue with the current digital crossovers was and still is the D/A conversion, and output stages. All of them that I have heard have been analytical, sterol, and not musical in comparison to what I am used to. Now if you compare them to an average or comparable DAC then the current digital crossovers win every time. But when you compare them to the passive crossover and a really high quality DAC, like the Tranquility SE DAC that I am using, then the passive crossover and Tranquility DAC really eats it up.

I have some V-1 drivers in stock and as soon as time allows I will try the open backed tweeter on the 8" coaxial used in the V-2 and design a passive crossover for it. Clearly it will step it up a notch.

Danny, have you had a chance yet to work on this upgrade yet? I would like to use that open backed tweeter in my build.

Danny Richie · « **Reply #50 on:** 9 Apr 2011, 08:16 pm »

Quote from: cleestedwood on 9 Apr 2011, 03:26 pm

Danny, have you had a chance yet to work on this upgrade yet? I would like to use that open backed tweeter in my build.

Not yet. I for sure won't get to it for at least a week after the show in Atlanta.

Donald · « **Reply #51 on:** 13 Apr 2011, 01:33 am »

Danny,

Are you going to be at the show in Atlanta. I did not see GR listed as an exibitor? If so, what speaker are you going to have singing?

HAL · « **Reply #52 on:** 13 Apr 2011, 01:35 am »

From what I read Danny is on the road to Axpona at this time.

He will be with Carnegie Acoustics. Not sure what speakers he will be demoing for them.

jtwrace · « **Reply #53 on:** 13 Apr 2011, 01:39 am »

Quote from: HAL on 13 Apr 2011, 01:35 am

From what I read Danny is on the road to Axpona at this time.

He will be with Carnegie Acoustics. Not sure what speakers he will be demoing for them.

http://www.carnegieacoustics.com/pdfs/CAAXPONA.pdf

Rocket_Ronny · « **Reply #54 on:** 13 Apr 2011, 02:54 am »

Carnegie will be showing the new CST-2. Here is a sneak peek I have on our site. This was before drivers installed. They will be showing the black ones I believe. It is a wwmtmwwww design with the BG Neo 3 tweeter and 5.5 inch paper woofs. Top crossover parts, etc.

http://www.hdaudio.ca/HDAudio/Speakers_1.html

Rocket_Ronny

jimdgoulding · « **Reply #55 on:** 13 Apr 2011, 05:03 am »

Tyson- Damn, son, workin as hard as you have and puttin it on the line like that deserves some serious appreciation. You have mine, most seriously.

Tyson · « **Reply #56 on:** 21 Apr 2011, 06:55 pm »

Thanks Jim!

Updated the first post with the following info:

Try, try, try to get these puppies more than 3 feet into the room. Read up on the AudioKinesis site about why this is important. In summary, it's due to the rear signal not being delayed long enough, which causes two bad problems - 1st, image smear, things tend to run together more than they should, optimally. 2nd, it causes tonal shifts that make it necessary to use more EQ than you would otherwise. By pulling them out to about 4 feet (measured from the front baffle, so not as far as you might imagine), you get a much smoother tonal balance and better imaging by default, so less messing around in the DCX. Always a good thing.

Since my upper mids are less re-inforced by the room now, I can also lower the point that I bring the bottom woofers in. I went from 200hz, to 150, to 120, to 100, finally to 80. Since the midrange driver goes down to 90 hz strong, I can use the bottom woofers at 80hz w/a shallow slope of 6db and get VERY strong mid/low bass now without it touching the midrange at all. The subjective result is that the presentation has change from a "lower midrange centered" presentation, a bit laid back, to one that is not mountain-stream clear, with tensile strength, jackhammer dynamics, and center-of-the-earth explosive bass. D@mn, and I thought it couldn't get any better!

jtwrace · « **Reply #57 on:** 21 Apr 2011, 06:58 pm »

Tyson,

Are you running a stock DCX?

Tyson · « **Reply #58 on:** 21 Apr 2011, 07:34 pm »

Yep, a stock DCX. I'm thinking about changing over to the new 2x8 miniDSP, but I might wait for them to come out with one that has a case. I like that it's able to use an external (linear) power supply, and doesn't need the XLR/RCA converters I have to use with the DCX. Also, the miniDSP is set to interface with consumer voltages, rather than pro voltages, which should allow me to get rid of these converters and isomax conversion boxes.

I'd consider modding the DCX, but it just seems pointless with the miniDSP having these advantages out of the box. Plus the DCX has so little space and mostly SMD architecture, so bleh.

jtwrace · « **Reply #59 on:** 21 Apr 2011, 07:37 pm »

Quote from: Tyson on 21 Apr 2011, 07:34 pm

Yep, a stock DCX. I'm thinking about changing over to the new 2x8 miniDSP, but I might wait for them to come out with one that has a case. I like that it's able to use an external (linear) power supply, and doesn't need the XLR/RCA converters I have to use with the DCX. Also, the miniDSP is set to interface with consumer voltages, rather than pro voltages, which should allow me to get rid of these converters and isomax conversion boxes.

I'd consider modding the DCX, but it just seems pointless with the miniDSP having these advantages out of the box. Plus the DCX has so little space and mostly SMD architecture, so bleh.

Gotcha. Do you use the converters and isomax stuff because otherwise you will get noise or just to make all the gains correct?

From what you describe it sounds like it will be hard to beat the DSP.