Which Components Should I Use?

[Wonderboy]

Hello Ian

I'm glad you approve of my using the 2012 and the 2226 together. The "peaky response" of the 2012 has generated a lot of interest on this thread, it's been kinda cool watching you guys go at it.

You are not the first to suggest going with three 2397 horns, Mr. Widget suggested the same earlier on another thread. Guess it makes good sense to use the same horns in the front on a HT system, to keep the timbre etc. the same. These 2397 horns seem hard to come by, guess there is not to many around. Personally, I like the look of those nice wooden horns, like the one in your picture of the speaker on the left that comes up when you make a post. I like wood, to me it's kinda like eating "comfort food" like mashed potatoes, but instead it's "comfort for the eyes" guess that must be instilled in us from back in the days before man invented concrete and plastic. Anyhow, I'm getting off topic, typical me (to much coffee), those S/H 2" TAD 4001's sound interesting and expensive, they must be good, are they not made by Pioneer?

Kevin.

[Wonderboy]

Hi Ian

I was just wondering, with your measurements a few posts earlier, you achieved an 18dB slope with a second order xover, is that common?

Kevin.

[Ian Mackenzie]

Because I am a Time Lord I can pull those tricks.

(Its has to do with the Q of the filter and its interaction with the driver natural response. The inital rolloff matches and 18 db slope but the ultimate slope is a wee bit softer)

The idea being that if the inital slopes are known it makes the power response and summing on axis more predictable. Sharper slopes tend to be better at these frequencies where the cone transducer is crossing over the a horn or a wave guide that may be not aligned with the woofer.

[Wonderboy]

Ok "Time Lord", so all I need with for my low pass on the 2012 is 1.38Mh and a 49uF?

Kevin

P.S. Is that you selling the wooden TAD horns on ebay?

[Ian Mackenzie]

I hope you are not making fun of me?

I take my job very seriously.

To answer your question no. Selling tad horn my ass.

[Ian Mackenzie]

Ok "Time Lord", so all I need with for my low pass on the 2012 is 1.38Mh and a 49uF?

Kevin

What did I say earlier??

http://www.audioheritage.org/vbullet...3&postcount=27

I hope your not a Zilch Clone.

[Wonderboy]

I would never make fun of a "Time Lord" , I know what's good for me! (I have a big smile on my face, just try'n to get ya going, haha!) I do respect you, anyone who can eat pasta and figure this stuff out at the same time, I RESPECT! (just don't let it go to your head).

I never figured out how to use the "quote" thing, but never tried yet. But I must apologize I was scanning through the posts and guess I missed that one you quoted, that one you said earlier about needing actual driver data etc and focused on the measurement graph one.

What's wrong with selling TAD horns, they look nice and the price is right?

Don't pick on Zilch, he's been good to me, I think, little short bursts of info, but good info.

After seeing those TAD horns for sale and your offer on the TAD drivers (after having a couple beers) I was very tempted to go for it, thought about selling my wedding ring, which might not have been such a bad idea but I don't think I would live long enough to enjoy the music.

Kev.

[Ian Mackenzie]

I think selling the ring could be a bad omen!!

No problems

You could try those values just for grins but it is not like a piece meal thing.

You need to properly mount and load the driver on a baffle and do some realistic measurements.

I was tempted to buy a pair but they are very pricey.

I dont know what end of Canada you are in but yo might want to talk to Earl or meet up with a local group of dudes who can steer you the right passage.

The thing is the 2012H is a world class driver and nothing less than perfect would be right.

[Baron030]

There are other considerations such as what baffle is the driver on and what is the voice coil x, y, z orientation as well as the mic distance and drive voltage but that's out of scope in this particular instance.

Thinking about I think, I have tested this driver hundreds of times proto typing various EQ circuits. Well, here are the latest and greatest test results that I have been able to come up with on the 2012H driver. Since, some people prefer closed boxes over bass-reflex enclosure for their mid-bass/mid-range drivers. I decided to run two complete sets of tests. So, one set was done with my ports plugged. In any case, the enclosure has a net internal volume of 0.5 cu ft. The front of my enclosure is 26.5” wide and 46.5” high. And the distances between the center of the 2012 driver and each edge are as follows 24.5”, 22.0”, 14.75” and 11.75”. So, I hope that covers all the baffle details. The mic distance was 1 meter from the 2012H driver and it was placed at the same height as the driver. Since, the center of the voice coil is only 24.5 inches above the floor a layer of R11 fiberglass was placed on the floor to reduce its reflection. And the next closest reflecting surface is a concrete ceiling, and it is just 10.56 milliseconds away. For charting purposes, I used the MLS processing tools and db shifted the all of the outputs to 0.00 dBV @ 1,000Hz. And other then gating to remove room reflections, no other processing was done.
By normalizing the data this why, it is then possible to make comparisons between each of the charts. The first chart shows the closed box and ported enclosure impedances of my right driver. The second chart shows the response of two drivers when each is mounted in a closed box. And the third charts, shows the drivers when each is mounted in a bass reflex enclosure. The forth chart shows how a 1.5mH coil can be used to flatten the response. And the final chart shows what my 0.3mH, 82.01uF, 10ohm, LRC EQ circuit can do.

And for anyone that is interested, I will be happy to post the CLIO MLS and SINI files or I can even export the data and post it as ANSII text files.

Baron030

[johnaec]

It's almost gotten to the point of complication that I'm almost thinking I should just sell these NIB 2012H and other drivers and start working towards some pre-built ___________________funds... Realistically, a pair of PS1400's to go with my PT800's would probably keep me happy right now.

Unfortunately, much as I've wanted to work towards some kind of dream system, I'm dealing with some medical issues right now where it's getting too hard for me to try reaching any of the even lower goals much of the time. Hopefully, things may change... In the meantime, I'm still watching, but may not have as much active input as I'd like.

John

[Baron030]

Well, I tried something new today.
Other than uploading some Jpeg photos, I have never tried uploading data files before.
The attachment is pretty much self explanatory.
Unfortunately, the CLIO files appear to be too large to post, even when zipped.

Baron030

[Ian Mackenzie]

Baron Von Clio Nicemeister,

Can you take a pic and attach of the baffle and measurement set -up please.

Ian

[Baron030]

Hi Ian

Doh!
Somehow, I just knew that I should have pulled out a camera and taken a few pictures while running these tests. And I just got through putting everything back in its place. Every time I do these tests, it like ripping up my living room. Well, I try to follow all of the procedures in Joseph D’Appolito’s book on testing loudspeakers. So, the enclosures are pulled towards the center of the room away from all of the walls. The biggest challenge is the slap echo off of the ceiling. There is nothing I can do other then limit the time domain of the measurement, which in this case was started at 2.90ms and stopped at 7.50ms before the slap echo could arrive. I wish the weather was not so cold. Otherwise, I would have done these measurements outdoors, terrorizing my entire apartment complex 120db MLS impulses. And I am just kidding about running tests at 120db.

The drivers were tested in the DIY enclosure pictured in my Avatar. And I simply measured all of the distances between the center of the 2012H driver and the edges of the enclosure, which I assumed would describe the baffle adequately.

Is there something that looks really wrong or very odd with my results? In a way, I am still learning the fine points of this software package. So, I would appreciate your input.

Baron030

[Ian Mackenzie]

Hi Ian

Doh!
Somehow, I just knew that I should have pulled out a camera and taken a few pictures while running these tests. And I just got through putting everything back in its place. Every time I do these tests, it like ripping up my living room. Well, I try to follow all of the procedures in Joseph D’Appolito’s book on testing loudspeakers. So, the enclosures are pulled towards the center of the room away from all of the walls. The biggest challenge is the slap echo off of the ceiling. There is nothing I can do other then limit the time domain of the measurement, which in this case was started at 2.90ms and stopped at 7.50ms before the slap echo could arrive. I wish the weather was not so cold. Otherwise, I would have done these measurements outdoors, terrorizing my entire apartment complex 120db MLS impulses. And I am just kidding about running tests at 120db.

The drivers were tested in the DIY enclosure pictured in my Avatar. And I simply measured all of the distances between the center of the 2012H driver and the edges of the enclosure, which I assumed would describe the baffle adequately.

Is there something that looks really wrong or very odd with my results? In a way, I am still learning the fine points of this software package. So, I would appreciate your input.

Baron030

Hey,

I have the same problem doing tests, my favourite is the sweep.

Sorrry I did not twig it was your avatar.

Cool system

Nothing wrong but the peak at 1 k hertz is off.

I saw from measurements of another tightly packed baffle recently and the proximity of the ports made quite a different. Nothing you can do about that as its all about what happens on your baffle. The horn immediately above could also have an effect. They are really touchy frequencies.

You have probably aleady tried this but I would try just covering the ports and trial more fibre glass inside.

http://www.trueaudio.com/st_diff1.htm
http://www.frazierspeakers.com/download/bounds.pdf

http://www.pvconsultants.com/audio/d...ownloadbds.htm

[Wonderboy]

Interesting stuff guys, Baron and Ian, I have been doing some reading on crossovers and think I might go back to the active crossover, seems to have WAY less complications, not sure if I can swing it or not but it might be worth a try.

To bad that Johneac sounds like he is losing interest, I know how you feel John, it sounds pretty complicated but don't give up on your dream system, you might never forgive yourself. It's not as complicated as it sounds, even if you don't do it perfect, I don't think people will notice or measure it.

Thanks again for all your advice guys it is much appreciated. Just for the record, I was not making fun of you Ian, I kid around a lot, maybe to much at times, I was laughing with you, not at you.... Ahhh, now that I got that off my chest, I'll go back to my reading, catch ya's later!

Kevin