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07-07-2005 Post does not mapped to Knowledge Tree
skushino
Seattle, WA
Posts 85
Joined on 07-07-2004

Post #: 1
Post ID: 1155
Reply to: 1155
Making it sing...
All-

I'm optimizing new speakers, but the deep subject matter is a little new to me.  Will this work?

Using a pair of Welborne Labs DRD300B SET amps (tapped 8ohms) with a 3-way passive crossover to integrate these drivers.  Here is the "default" crossover set-up, as supplied by the designer:

-Electro Voice EVM15L woofer, 8ohms, 80Hz horn, 1.5mH coil
-Vitavox S2 midrange, 15ohms, 350Hz horn, 5uf cap, 2.5dB L-pad
-Fane ST5022 bullet tweeter, 8 ohms, 1 uf cap, 2.8dB L-pad
-There is also a subwoofer that rolls in beginning ~70Hz using an active 4th order low-pass filter and 5-6dB bass boost ~30Hz

I want to "optimize" this crossover network to extract the best these drivers have to offer, and remove components where it will do no harm:

- Remove L-pads from mid and tweeter (sounds a little brighter, yet "more pure" and "better" to my ears)
- Remove the 1.5mH coil from the woofer.  Again, sounds clearer w/o the coil to me.  Any adverse impedance matching issues?
- Add a 80Hz 1st order high-pass filter before the amps. The Welbornes have 100k input Z, preamp has 130ohm output Z. Install a .02uf cap at the amp inputs or pre outs.
- Use the S2 lower ~1100Hz replacing 5uf cap with 10uf cap
- Still working with the Fane, but want to experiment with other tweeters like Fostex, Raven or EV T350 (never heard these but interested enough to listen).

Does this sound like a good idea?

Thanks much.
scott

07-07-2005 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,767
Joined on 05-27-2004

Post #: 2
Post ID: 1157
Reply to: 1155
I do not think I said a lot….

Scott,

 skushino wrote:
- Remove L-pads from mid and tweeter (sounds a little brighter, yet "more pure" and "better" to my ears)

Lpad sets the attenuation and this is the parameter that should be tuned without fantasizes and subjectivism. Get RTA and set the band-pass of acoustic pressure form the channel identical. In context of 4-chanal installation the canals do affect and do mask each other but still to set them evenly is the very basic and very essential think to do. Later on when you get some experience between what you do and what you hear then you might bend the rules and shape the sound in the way you wish (and I do not think that it would be correct thing to do) but nor now set them evenly.
 skushino wrote:
- - Remove the 1.5mH coil from the woofer.  Again, sounds clearer w/o the coil to me.  Any adverse impedance matching issues?

This coil is low pass filter over 1K and it has nothing to do with “impedance matching”. The necessity of this coil is subject of VERY many valuables: how the coil of the MF can scent it electrically, what the design of the woofer in this horns, the design of the horn, and in the end of the ends: how you upperbass channel sounds at it higher knee…. With some woofer and with deep enough harms you might not use this filter at all… it all depends….
 skushino wrote:
- - - Add a 80Hz 1st order high-pass filter before the amps. The Welbornes have 100k input Z, preamp has 130ohm output Z. Install a .02uf cap at the amp inputs or pre outs.

If your horn has 80Hz flare rates (or least what Bruce states) then 80Hz order high-pass it too high. I would start form ~40Hz to unload the LF form it. However, I would be questioning if it really were necessary. First of all this horn has back chamber that changes the rules of the game and marks the horn less sensitive to the overload the flare with LF.  Second, Bruce used the fairly low Fs driver in there with large trout that makes them to act at lowest cut off as the direct radiators…. I very much doubt the it would be necessary.
 skushino wrote:
- - - - Use the S2 lower ~1100Hz replacing 5uf cap with 10uf cap

Are you saying that S2 has not as good lower mid range than heavy and dirty EVM15L? Well, I disagree and at my taste you cut S2 too abrupt. Not to mention that you have it sitting in the 330hx horn…
 skushino wrote:
- - - - -Fane ST5022 bullet tweeter, 8 ohms, 1 uf cap, 2.8dB L-pad

Get rid the L-pad and move the Fane up on the slope. Try to run it with ~ 0.3uF

Rgs,
The caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-07-2005 Post does not mapped to Knowledge Tree
skushino
Seattle, WA
Posts 85
Joined on 07-07-2004

Post #: 3
Post ID: 1158
Reply to: 1157
Re: I do not think I said a lot….
 Romy the Cat wrote:

Get RTA and set the band-pass of acoustic pressure form the channel identical.


Yes, I need to get one!  Although Bruce and my tech guy both advise that the RTA may cause more problems than it solves, without proper interpretation. 

 Romy the Cat wrote:

This coil is low pass filter over 1K and it has nothing to do with “impedance matching”.


Impedance matching is Bruce's description, not mine.  The crossover F is ~850Hz.

 Romy the Cat wrote:

If your horn has 80Hz flare rates (or least what Bruce states) then 80Hz order high-pass it too high. I would start form ~40Hz to unload the LF form it. However, I would be questioning if it really were necessary. First of all this horn has back chamber that changes the rules of the game and marks the horn less sensitive to the overload the flare with LF.  Second, Bruce used the fairly low Fs driver in there with large trout that makes them to act at lowest cut off as the direct radiators…. I very much doubt the it would be necessary.


I was thinking that beginning the rolloff an octacve lower is better.  This confirms.  I will try both ways over the weekend. 

 Romy the Cat wrote:

 skushino wrote:
- - - - Use the S2 lower ~1100Hz replacing 5uf cap with 10uf cap

Are you saying that S2 has not as good lower mid range than heavy and dirty EVM15L? Well, I disagree and at my taste you cut S2 too abrupt. Not to mention that you have it sitting in the 330hx horn…


One of my S2s is sick, and not singing.  There is resonance / buzzing around 1k.  Still working on fixing it.  So for me, the EV woofer really does sound better than the S2 in this range.  I am looking forward to fixing this driver, and hear what it's capable of.

[quote user="Romy the Cat]
 skushino wrote:
- - - - -Fane ST5022 bullet tweeter, 8 ohms, 1 uf cap, 2.8dB L-pad

Get rid the L-pad and move the Fane up on the slope. Try to run it with ~ 0.3uF

Rgs,
The Cat


Great - I will try.

Thanks a million for the feedback.  It will keep me busy this weekend ;-)

Scott
07-07-2005 Post does not mapped to Knowledge Tree
skushino
Seattle, WA
Posts 85
Joined on 07-07-2004

Post #: 4
Post ID: 1159
Reply to: 1157
Hot rod x-over

Somehow I massacered the formatting of the last reply. 

The past days I was listening to the speakers in every imaginable configuration.  Sometimes I based my changes on "accepted theory" of crossovers and math, other times I just made changes in component values to gain a feeling of how I can affect the sound.

The version I always came back to, and am listening to now, is bare bones: nothing on the upper bass, 5uf cap on the mid range, 1uf cap on the tweeter, and 4th order low-pass on the sub. 

Yes, it is too bright.  But not unlistenable.  It's kind of like moving up 15 rows at the symphony.  More importantly, there's a "cleanness" to the sound.  It is pure and uncorrupted and more free.  I like it. 

So, the challange seems to be balancing the result, while minimizing the pollution from the components.

07-07-2005 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,767
Joined on 05-27-2004

Post #: 5
Post ID: 1160
Reply to: 1159
Tell me "as is".
Ok, can you in subjective trims describe what do you feel is wrong with your sound. disregard the speakers and channels, tell juts your pure reaction to what it is.

The cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-07-2005 Post does not mapped to Knowledge Tree
skushino
Seattle, WA
Posts 85
Joined on 07-07-2004

Post #: 6
Post ID: 1161
Reply to: 1160
Re: The problems

Romy, I'll limit my answer to only speaker-related problems. 

1) Still too bright sound.  Not hard or edgy, just too much top end.  My local guy suggested trying a single resistor in series, rather than an L-pad, to tone down the tweeter.

2) Mid-band presence ~1k - 1500Hz.  The upper bass mass roll-off is around 850Hz, and the mid driver is x-overed ~2100Hz, so on some music it sounds like some energy (presence) is missing in this range.  Removing the coil from the woofer helps, as it should.  Fixing the S2 and running it down to ~800 should help, too.

3) Sub integration.  Still a moving target.  Trying to balance too much overlap between subs and main, and control quality of bass.  I'm seeking toneful, colorful and balanced bass, that sounds big and round, consistent throughout my room.

4) Acoustic space.  Recreating a sense of place and scale for individual instruments and musical notes.  Specifically, layers and layers of depth, and the number and concentration of musicians.  The side to side lateral space is not a big challenge, but getting the other parts right is more interesting.

On the first two, I have some clear ideas to make progress, and am confident that over time they will be solved.  The second two are a bigger challenge for me.  I believe the solution will take much longer (probably months at least), and only become known after much positioning and repositioning of the speakers and sub.

Too bad we aren't neighbors.  I would invite you and your RTA over for some sushi and music.  In the meantime, I'm figuring things out on my own, one day at a time.

Best,
Scott

07-07-2005 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,767
Joined on 05-27-2004

Post #: 7
Post ID: 1162
Reply to: 1161
The problem is not THE problem.

Scott, you see, this is the problem. You do not talk about the problems “as is”. All what I was asking was the acknowledgment/recognition/identification without context of loudspeakers. Your listening/assessment awareness is completely grounded to the porpoises and the means of reproduction. The practice of listening the loudspeakers  (or any other element) is the very first thing that should be discarded as with this practice any attempts to build a proper music reproduction system are condemned to fail.

 skushino wrote:
1) Still too bright sound.  Not hard or edgy, just too much top end.  My local guy suggested trying a single resistor in series, rather than an L-pad, to tone down the tweeter.

Forget about the tweeter. You should make the system sound properly without the tweeter. Do not use it until the system sound perfectly acceptable.

 skushino wrote:
2) Mid-band presence ~1k - 1500Hz.  The upper bass mass roll-off is around 850Hz, and the mid driver is x-overed ~2100Hz, so on some music it sounds like some energy (presence) is missing in this range.  Removing the coil from the woofer helps, as it should.  Fixing the S2 and running it down to ~800 should help, too.

You have to clearly undusted that without the actual RTA measurements what you say and what calculations indicate are juts shaking air and have no purpose. Why, when you bring 1/12dB RTA along with a phase tester and run some sweeps you will see why. So, sorry, I will not be commenting on it … and I would suggest do not waste your time and do not even to think about it until you have an objective tools to control what you do.

 skushino wrote:
3) Sub integration.  Still a moving target.  Trying to balance too much overlap between subs and main, and control quality of bass.  I'm seeking toneful, colorful and balanced bass, that sounds big and round, consistent throughout my room

The same as above.

Anyhow, while you are straggling with Bruce foolish advice do not use analyzer “because it creates problems” I would suggest you stop visiting the “full of wisdom internet sites” and go for a rehearsal of your local Chorus Society. You might discover much more about speakers in there then during a conversation with Mike Lavigne-like idiots and perhaps you might develop some vocabulary that your help you to identify for yourself the problems with Sound instand the problems with a playback.

Rgs,
The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-07-2005 Post does not mapped to Knowledge Tree
skushino
Seattle, WA
Posts 85
Joined on 07-07-2004

Post #: 8
Post ID: 1168
Reply to: 1160
Re: "as is".
 Romy the Cat wrote:
Ok, can you in subjective trims describe what do you feel is wrong with your sound. disregard the speakers and channels, tell juts your pure reaction to what it is.

The cat


Romy, I now see you were asking a totally different question.  But, I'm still not fully understanding your meaning.  This thread was originally written for input about bringing a pile of horns, drivers and wires to life, to make it sing and come alive.  They are Bruce's product, but not fully his, because it differs from his stock product.  He did not assume full ownership and responsibility of the design, and consequently I feel like I took delivery of an incomplete product.  After my initial order, it took 7 months to finally receive all the parts from Bruce.  During that time, he listened to the new drivers for an hour or two, in one afternoon, and then shipped them to me.  He was probably tired of talking to me everyday for two months, asking him when he was going to ship.  He basically said "Scott, I am not familiar with this driver, and I made a crossover you can start with.  You might want to do further work yourself."  I'm kind of paraphrasing him, but that was the general message.

My goal was to retain the best of the sound from my old speakers, which I enjoyed in many ways, and also gain a freer sense of dynamics.  Not so much loud and soft, but the ability to move quickly and gracefully from soft to loud and back again.  First and foremost, I wanted to "do no harm" to my exisiting sound.  I want to retain the gentle, round shape of notes, even when music is violent (I think you describe this as the slope of transition?) and the wonderful sense of acoustical space they (old speakers) are capable of.  The biggest problem was a sense of constricted dynamics.  Not bad per se, but still kind of constipated-sounding, that sucked energy and life out of music, whether large or small scale.  What else to expect with 87dB speakers!
07-07-2005 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,767
Joined on 05-27-2004

Post #: 9
Post ID: 1169
Reply to: 1161
Do NOT even touch the woofer and tweeter!

 skushino wrote:
Romy, I now see you were asking a totally different question. 

Disconnect tweeter and woofer and connect juts MF channel with 3uF and upperbass channel with whatever low pass you wiling to use. Listen music on this two-channel setup at least for a month. Set the output of both channels at identical volume and those two channels should sound perfect “as is”.  In fact with this 2-chanls setup you will be able to adjust the only one parameter – the low-path at midbass… if you need to. In fact I would start with the listening juts the upperbass channel….

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
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