[Chops]

Hello everybody!

So it's been about 3.5 years since I've been on here! WOW, a lot has changed since then. I no longer have my dipole subs or anything. In fact, everything in my system has changed. The ONLY thing that has remained the same is my trusty and faithful Panamax MAX 1000 power conditioner.

Anyway, as the title tells it, I have built an open baffle verion of the Usher D2 loudspeakers. Originally, I had all intentions of building near exact clones of the D2's. Ported enclosures tuned to 27Hz, a dedicated enclosure for the horns, even the exact same Usher 15HM 15" drivers. Well, that's kind of what I ended up with, minus the enclosures. This is what happened.

I was waiting a while to start this project mainly because I was still researching the detailed specs of the D2 enclosures. In the meantime, instead of having the Usher 15HM drivers sit in their shipping boxes in my bedroom for months doing nothing, I decided to build simple OB's to get the drivers up and running just to break them in. Well, that was the mistake I made in the whole "D2 cloning" project. It was rather late at night when I got the OB's completed, around midnight IIRC. I couldn't wait till the next morning to hear them, so I insisted on firing them up and playing them at whisper levels while the rest of the family was asleep. Performing a couple of really quick tweaks to the EQ (less than a minute), I had some decent sound coming from them. I must of sat there on the couch for about an hour or more just listening to them! That was about 3 months ago.

To make a long story short, I have since upgraded/replaced my Rane AC22B crossover and Behringer DEQ1024 to the Behringer DCX2496. This unit has full control of the front three channels of my system. The center channel uses an Usher 15PA, all three channels use an Altec 511B horn. The mains use Altec 902-8B drivers while the center channel uses a 902-8T. I first had the DCX set to Linkwitz 48dB per/octave, but today I switched to Butterworth 48dB per/octave. With all the dealy and EQ settings remaining the same, I think that the Butterworth setting sounds better, but will still play around with it some more.

BTW, I know that the 511B for the center channel isn't in the best position for dispersion and such, but it actually sounds pretty darn good at the moment. Of course, the DCX2496 helps out a lot in tuning it to blend in well with the mains.

I'll go on a bit more about the setup later, but it's late now and I've gotta hit the sack. Anyway, here's a few pics of the current setup. Please feel free to ask questions or make comments. 

[Chops]

Today I spent 4 hours tuning the front three channels (about 3 hours alone just on the mains). Before I did anything, I took some measurements of everything as is, then I set all of the previous EQ settings back to flat and started over from scratch. Actually, they are still saved to memory under a seperate file. I also repositioned the center channel back to the way it was, with the enclosure on its side and the 511B centered on top, but after I took the initial measurements. The horn was putting out some nasty peaks and dips all over the place due to the vertical position, which I was already warned about. but hey, I wanted to try it just for poops and giggles. 

Just a quick FYI, from all the previous EQ settings on the DCX2496, I still had 13% processor power left. After doing things differently today and getting a finer tune done, I am now down to only 5% processor power!

Oh, and something I realised today while tuning, I ended up having to use totally different xover points for all three channels in order to have them match on SynRTA and to my ears. When I tune the system, I normally tune the woofers first one at a time. Once they are done, I mute them and tune the horns one at a time. Well, a few days ago, I was running out of time and just did a quickie tune with SynRTA and each channel seperately but with both the woofers and horns running together.

I'm guessing that due to the room acoustics and how everything is laid out in the room is what caused the differences in xover frequencies needed. For example, the left channel is set to 754Hz, the right channel is set to 738Hz, and the center which is not only a different driver, but also in a sealed enclosure, is set to 722Hz. For whatever reason, this is the only way I could get the woofers to match up by ear and measured. The same thing holds true with the horns. Now they all sound even and correct and their roll-offs are at the same frequencies. Odd, huh?

The EQ setting for each channel are all totally different, except for the horns for the mains. Those two are just about identical with a slight HP filter boost around 7.8kHz, about 2dB max. The center channel horn is a little different with no HP filter needed but a BP filter with a small amount of boost around 3.5dB at 1.25kHz. The woofers on the other hand are a totally different story. These are also what took up all that extra processing power and time!

The good news about all of this is that everything finally sounds the way it should. The mains sound is very coherent, life-like and natural with plenty of imaging and soundstaging to spare. It's definately the best sound that's ever been in this house! And talk about slammin' bass in your chest! Holy cow, these things hit hard. They have very natural, very solid, very usable output down to 35Hz, maybe a little closer to 30Hz. Bass drums are reproduced with a very realistic impact like the things are right there in the room with you. And those Usher 15HM drivers are only soaking up a peak of 30 watts to reproduce those bass drums at nearly 105dB at my sweet spot. I could have easily gone louder, but it was already getting too loud and I value my hearing very much. And just think, I still have another 140 watts just sitting there waiting to be used, but they never will be with these OB monsters.

Anyway, here's a few plots that were taken today. They are as follows:

1) Left Channel


2) Right Channel


3) Left + Right Channel



And here's one of the center channel. Please note that this is with the 50Hz internal xover active in my Pioneer Elite reveiver.

[Chops]

Wow, this is a really helpful crowd here. Two totally different threads and not one single comment or anything on either one!


Now I know why I stopped coming here. 

[ooheadsoo]

What can I say...your project is overwhelming!

You know...it does seem halfway like a Emerald Physics CS2 "based" speaker.

I like the second pic, btw.

[zipidachimp]

  as someone who's dealing with 8" woofers and 3" FRs, your project appears over the top. I really appreciate the effort though and I bet it sounds good.
just not in my league. carry on!

[Bemopti123]

Cheer up Chops, when I saw your post and your set up, my jaws just dropped.  Although I have seen other sites with pictures of the very same type of set ups like you have, your story and the way you describe your set up sound makes me drool.  Just 30 watts to run those woofers?  That is great.  Although I do not have nearly the space you do, you got me thinking. 

Keep the developments coming. 

BTW: people might not have replied to your post because they might have had a long night and it is Saturday morning.   aa

[mcgsxr]

Over the top, what IS that?

Y'all might not be aware, but Chops is the guy who years ago posted about H frame OB subs using 4x15 inch Pyramid drivers...

Love his input!

[Chops]

Over the top, what IS that?

Y'all might not be aware, but Chops is the guy who years ago posted about H frame OB subs using 4x15 inch Pyramid drivers...

Love his input!

You seriously remember that?! Wow!

Speaking of "over the top", I am planning on designing and building an all new subwoofer system. Yes, a system.

/It will consist of no less than eight GR Research SW-12B drivers in two seperate enclosures on either side of the center channel. Each enclosure will be roughly 8cf sealed with four 2cf sealed sub-chambers. Obviously, each chamber will house its own SW-12B driver, and after driver displacement should be somewhere near 1.8cf, which is more than enough for these drivers. An all new center channel enclosure will be built and all three enclosures will be tied together to form a small "stage" in front of the projection screen. I'll then use a Behringer FBQ2496 to dial it in, and still power them with my Crown XTi 1000. They will be wired to 4 ohms mono so the XTi 1000 will provide them with 1400 watts. Even with 1000 watts input, these drivers should be only reaching an Xmax of about 12mm at 20Hz! Of course, I will never use nowhere near that amount of power with them.

The reason for such an "over the top" subwoofer system?

Well, multiple 12" drivers in small, sealed enclosures working together will be very fast and accurate and clean because they will be operating well below their limits, will provide very tight and punchy bass as well as be able to reproduce detailed bass down well below 20Hz. I'm shooting for a nice, flat response down close to 10Hz. Even at very high output levels, they will be working well within their operating range. This translates into low noise, distorsion, etc, etc with plenty of room, excursion and power left over for transients. I believe this will be the most cost effective, realistic way of matching the performance of my OB's and getting that much closer to the real deal (actual performance).

[JANDG]

Yep, I been eyeballing your horn/OB rig since you posted it a while back. I suspect it is wonderull in everything I would want out of such a speaker gig. I am a tube guy so I would be in heaven. The subs system you propose is "NUTS",, very cool but you are going to break your house Chops..10hz of the real deal would be a experience for sure. Check you foundation & substructure from time to time..just kiddin man..When I go for another OB system for larger scale it will be along very similar lines. The servo sub drivers are now avalible from GR..? I can  say your OB/hybrid's would stomp the crap out of all my OB's & easily.NICE......

[JimJ]

Very cool idea, and nice pictures

[SET Man]

Wow, this is a really helpful crowd here. Two totally different threads and not one single comment or anything on either one!


Now I know why I stopped coming here. 

Hey!

   Easy there Chops We could be a bit slow here sometime 

   Anyway, that is one interesting home brew speaker there. Would love to see impressions of people especially non-audiophile when they walk in and see your system!

Take care,
Buddy

[mcgsxr]

Over the top, what IS that?

Y'all might not be aware, but Chops is the guy who years ago posted about H frame OB subs using 4x15 inch Pyramid drivers...

Love his input!

You seriously remember that?! Wow!

Oh yes my friend, part of the ritual of becoming a moderator here on AC is to memorize all usernames, posts, and general information related to the forum one is to be responsible for!   

OK, so the reality is that I am an OB bass junkie, and so your work on another forum really caught my attention, as I clearly value the ROI of DIY!

Looking forward to hearing about how that bass build goes... I need to stay in touch with you, you seem to go through bass drivers over time, and I am always looking for the perfect sub.

I do see that Kevin has created a doozy, over in the DIY Cable forum, for excellent OB or IB bass on the cheap!  http://www.audiocircle.com/index.php?topic=50353.0

[ttan98]

10hz of the real deal would be a experience for sure. Check you foundation & substructure from time to time..just kiddin man..

Just like having a windmill(wind powered generator) next to your house or a few doors down the street...

[Bemopti123]

Over the top, what IS that?

Y'all might not be aware, but Chops is the guy who years ago posted about H frame OB subs using 4x15 inch Pyramid drivers...

Love his input!

You seriously remember that?! Wow!

Oh yes my friend, part of the ritual of becoming a moderator here on AC is to memorize all usernames, posts, and general information related to the forum one is to be responsible for!   

OK, so the reality is that I am an OB bass junkie, and so your work on another forum really caught my attention, as I clearly value the ROI of DIY!

Looking forward to hearing about how that bass build goes... I need to stay in touch with you, you seem to go through bass drivers over time, and I am always looking for the perfect sub.

I do see that Kevin has created a doozy, over in the DIY Cable forum, for excellent OB or IB bass on the cheap!  http://www.audiocircle.com/index.php?topic=50353.0

Although I read that thread, I did not realize that Kevin's woofer would be suitable for OB applications.  That is great.  The price cannot be beaten.  I was also wondering what woofer would be suitable for OB applications, and the woofers that Chops uses were great for it, but perhaps these new woofers might be better and for the price, it is a bargain.   

[Chops]

Although I read that thread, I did not realize that Kevin's woofer would be suitable for OB applications.  That is great.  The price cannot be beaten.  I was also wondering what woofer would be suitable for OB applications, and the woofers that Chops uses were great for it, but perhaps these new woofers might be better and for the price, it is a bargain.   

Although those new drivers would definately be better than mine in the bass department, I doubt they would sound good up to nearly 800Hz like I am running my Ushers. Unless of course you are referring to my old dipole sub setup.

BTW, sorry for the really long delay on this thread. I kinda forgot about it.