WMTMW Open Baffle project - so far so good

JohnH12 · « **Reply #20 on:** 16 Jun 2016, 05:24 pm »

Quote from: brad944911 on 16 Jun 2016, 01:28 pm

I already have the Behringer ECM8000 mic(solid enough?) that I use with the DEQ-2496 to help equalize the room, but no software...got a suggestion?

I like ARTA, it's free and some pretty good tutorials on line.

mresseguie · « **Reply #21 on:** 16 Jun 2016, 05:43 pm »

Very cool looking, Brad!

Kudos to you and your project.

To my low carpentry skills viewpoint, the baffle appears almost flimsy compared to the various drivers it must support, but I'm guessing this isn't an issue(?).

Michael

brad944911 · « **Reply #22 on:** 16 Jun 2016, 07:41 pm »

John,
Thanks man, I'll give that a shot!

Michael,
Thanks man! Yea, it is a bit flimsy on its own, but once the 10's are bolted to the spine then secured to the "baffle" it's actually quite solid. Almost all the rigidity comes from the spine while the "baffle" is mostly to give a place to bolt the mids and tweet.

Take care guys,
Brad

nicoch · « **Reply #23 on:** 20 Jun 2016, 09:46 pm »

great work !

brad944911 · « **Reply #24 on:** 22 Jul 2016, 07:45 pm »

JohnH12,
I think I finally had that "AH-HA" moment. I just started experimenting with OB and coming from a closed box mindset(no pun intended), I've only really ever been worried about the effects of beaming...that doesn't really apply to dipoles!!! From all the info I got, it's actually quite opposite, as the frequency approaches the cone's diameter, an ON axis null is produced. It took me much reading and looking at plots to get it and understand why in an earlier post you said I didn't need to worry about beaming as much as the dipole nulls! I'm pretty sure I have it under control now and am already planning version 2 to this speaker. Feel free to correct me if I'm wrong.
Sorry I'm so thick skulled and thanks for hangin' in there.
Brad

JohnH12 · « **Reply #25 on:** 23 Jul 2016, 01:19 am »

Brad sounds close. The dipole null is a function of the baffle with. There no actual "on axis" null as that's filled in with the rear wave, but it's important to recognize you have lost constant directivity above this frequency. Meaning as you move off axis there will be drop outs or nulls. I'm no expert though, I still learn something with every build. In this last build I learned not to discount beaming. When I measured the Titan OB build I found the off axis response fell off sharply. The 2 inch TB full range just could not produce the off axis response a 1 inch tweeter can.

brad944911 · « **Reply #26 on:** 25 Jul 2016, 02:02 pm »

Hmmmmmmm....interesting. I based a lot of this current direction on the dipole model on the Linkwitz site. I know it's an ideal model, but it's giving me a chance to try something new. In particular, I'm trying to keep the pattern uniform by keeping each speaker playing from approx .17 to .5 of their wavelengths based on diameter of the speaker, still being mindful of the Center to Center spacing of the like speakers. Based on what you and Ed (Matavena) have given me so far, I think I'm gonna get rid of the XT19 and use 2 of the Aurasound 1" speakers in each channel from 2.5K & up. This has led me to the following freqs - 10's = 95-700Hz/ 4's = 700-2.25K/ 1's = 2.25K-20K. The characteristics that stood out to me were 1) the size for broad dispersion 2) the fact that it APPEARS to have an open back which would be great for increasing the dipolar response without having to use a rear facing tweeter and 3) the cost...not too bad.
Any thing here that you guys have tried and can ward me away from?
Thanks,
Brad

matevana · « **Reply #27 on:** 25 Jul 2016, 04:44 pm »

Quote from: brad944911 on 25 Jul 2016, 02:02 pm

This has led me to the following freqs - 10's = 95-700Hz/ 4's = 700-2.25K/ 1's = 2.25K-20K.

Hey Bradley!

I would suggest taking the RS100-8's up to about 4K, and having the Aurasounds take it from there. This way you can probably get by with only one Aura per side based on power handling, etc. I've never had luck with two "tweeters" placed close together; probably why you don't see this in many designs.

AJinFLA · « **Reply #28 on:** 25 Jul 2016, 04:49 pm »

When can we come hear them?
There is a nearly 100 member audiophile club in town, several DIYers. Just this past weekend, monthly meet was to listen to a pair of DIY horn speakers.

cheers,

AJ

JohnR · « **Reply #29 on:** 25 Jul 2016, 04:50 pm »

Hi, the Aurasounds (assuming you mean the NSW1) are very inefficient. Something to be aware of

brad944911 · « **Reply #30 on:** 25 Jul 2016, 05:35 pm »

Ed,
I may try running them up a bit higher when finished with the remodel, just because I see what you're saying. I really don't know if going any higher will cause issues, though. I want to avoid lobing in that range and the mids are at 6.5" apart so I'm trying to keep them below 2.5K. I took your comment on higher range dipolar response seriously and it led me to these little Aurasounds. Since they can handle the lower crossover but have extended response, I figured they would be worth a try. The biggest reason for running 2 of them is, as John notes, they are very inefficient. I regularly listen at higher volumes, so SPL is still a consideration, but NOT at the sacrifice of accuracy or quality. I'm hoping there will be no noticeable lobing since their CTC spacing will push that effect up to about 14K from my figures.

AJ,
No kiddin! I'd love to join in sometime. Is there a website? If not, can you IM me for the next time? I'd be glad to have some folks listen to these and better yet measure them to expose issues. I still don't have any software...been slacking!

John,
I saw your posts on these speakers a while back and that's how I confirmed they could be used as a dipole upper mid/tweet. I kinda figured on their inefficiency and that's why I'm thinking 2 of them. Luckily I have more than enough power to push them.

Thanks for the input guys and keep it coming! I've learned A LOT already and can't wait to try all this!

AJinFLA · « **Reply #31 on:** 25 Jul 2016, 06:53 pm »

Quote from: brad944911 on 25 Jul 2016, 05:35 pm

AJ,
No kiddin! I'd love to join in sometime. Is there a website?

http://www.meetup.com/Suncoast-Audiophile-Society/

brad944911 · « **Reply #32 on:** 25 Jul 2016, 07:19 pm »

AJ,
Thanks! Looks pretty cool

Brad

JohnR · « **Reply #33 on:** 30 Jul 2016, 03:36 pm »

Quote from: brad944911 on 25 Jul 2016, 05:35 pm

John,
I saw your posts on these speakers a while back and that's how I confirmed they could be used as a dipole upper mid/tweet. I kinda figured on their inefficiency and that's why I'm thinking 2 of them. Luckily I have more than enough power to push them.

Hi, but they only have about 5W power handling (from memory). With 2 you will get lobing at high frequencies. Probably not that bad considering how small they are. I would be inclined to consider going back to back to back tweeters. (Sorry if I mixed this thread up with something else).

brad944911 · « **Reply #34 on:** 30 Jul 2016, 08:49 pm »

John,
I went ahead and bit the bullet on 4 of these and got them installed. I shaved about 1/8 inch off on one side of each of these which allowed me to get them at 1-3/8 center to center so lobing will be real high up. I got them all integrated and I must say that I do like the sound of them in the system. They are still breaking in, so I'll try and get some pics and maybe some listening impressions soon. What I've noticed so far is that the speakers are not as easy to localize from a few positions on the couch, so maybe I have achieved my goal...to be continued. The thing that scares me most is, like you noted, their low power handling. I don't want to fall in love with them then continually kill them.
Brad

brad944911 · « **Reply #35 on:** 1 Aug 2016, 04:19 pm »

So I've been breaking these in and I really must say that you guys were right on with the suggestion to get more dipolar response up higher in the range than the original design. There is definitely an openness of the sound now. The "sweet spot" is much wider and doesn't collapse with moving over just one cushion's width on the sofa. They also sound very coherent, even without EQ'ing and so far no audible lobing. Overall I'm pretty happy. Here are a couple pics of the modified baffle. I will eventually redo them to a one piece design, but for now , this will have to do. It's summer in sunny FL and the islands are calling!! Thanks for all the guidance guys. I learned a lot on this project.

JohnH12 · « **Reply #36 on:** 2 Aug 2016, 01:11 am »

These just look great

JohnR · « **Reply #37 on:** 2 Aug 2016, 07:00 pm »

Nice (and fast!!) work! Look forward to hearing more.

brad944911 · « **Reply #38 on:** 2 Aug 2016, 07:00 pm »

Thanks man! I'm happier with the sound of this version, too. BTW I looked at that ARTA software and it's like 75 pounds....no longer free

When it's all said and done, I like the engineering and building challenge almost as much as anything, but I'd like to see whether the principles and ideas I learned and implemented really worked. Got any other suggestions? Right now I just turn on the Behringer and run the Auto Eq and it clears most things up, but I'd like to see what's REALLY going on.
Thanks again,
Brad

JohnH12 · « **Reply #39 on:** 3 Aug 2016, 10:47 am »

I used it in the demo mode

Ordering

ARTA Software is classified as "shareware". To use it you have to pay for the user license key. If you have no license key, you can freely use this software only in a demo mode. The demo mode of programs is fully functional except loading and saving of files.