Open Baffle Epiphany!

[jelly_bean]

Just wondering if anyone out there has used the Eminence Beta 12LTA on their baffle for any length of time? I followed the blog post from Godzilla (https://speakerprojects.wordpress.com) and built them with the same compression driver/waveguide combo on top of the H-frame along with a 1uf cap as the crossover. I've got about 15 hours on them and they sound pretty good, but I can't seem to get them to image or sound as smooth as I would have hoped. I have removed the dust cap and made my own phase plugs which did give a noticeable improvement.

Do these drivers open up more after more time playing? How does the imaging and soundstage compare with other drivers you have used, does this change over time as well?
FWIW, I built floor to ceiling corner bass traps, 4 wall panels.

till then, I'll play with placement and try to hang something in front of the giant sliding glass door on the "front" wall.

 

[Poultrygeist]

I enjoyed these Beta 12LTA's for a number of years. Hard to beat their grand sense of scale and efficiency. They don't image like smaller drivers and lack the refinement of the Zenith Alnico's which are also 12 inches. I sold mine recently to a friend and he loves them. I would have kept them but the Zeniths now occupy their baffle. The Emerald Physics of a few years ago used the 12LTA with a compression driver riding piggy back and firing through the Beta's throat.

 

[Poultrygeist]

Here's the Emerald Physics with the compression driver mounted to the rear of the Beta 12LTA with two Eminence Alphas 15's on bottom.

 

[Poultrygeist]

The reason I don't use bass traps with OB's is I don't want any absorption of the rear waves. My OB's sound better pulled out into the room with some distance from the rear and side walls. OB's are less room dependent than box speakers and should not be treated the same. Linkwitz has a lot to say on the subject.

 

[jelly_bean]

Thanks for the help. I will continue to enjoy them, but am building another baffle or two that allow me to mount 8" and 10" drivers. - because, why not? It takes about 5 minutes to swap them.

I do want to try those Tang Bands people rave about.

One other question about the Yung SD200 Plate amp (just confirming I have it set correctly): What do you have your volume set at? I have to keep it almost off or else it gets extremely boomy, and overpowering. I keep thinking I have something set up wrong. But everything seems to check out ok. FWIW, I haven't messed with the phase knob, and I adjust the crossover as I see fit.

Thanks for helping this newbie.

 

[Poultrygeist]

With the Zenith system I use a single SD100 which has plenty of power for two Alpha 15A ( 91+ dbs? ) and have it on the first mark above minimum. I don't care to hear much bass and would only want to recognize that it's missing when it's turned off. With a pair of bucket subs powered by an SD300 and a sealed sub also powered by an SD300 in the same system with the H-frames I keep all volume controls at very low settings.

You shouldn't see any movement of the Alphas when they're playing. I often touch them to make sure they're powered up.

I'm currently using a single Dayton APA150 to drive four Alphas in the Lowther system. To get adequate bass the Dayton stays at 3:00. Before switching to Yung Plate amps it took two APA150's bridged to power two H-frames.

 

[mkane]

Looking at 100's of pic's and plenty of reading is seems as though many have no scientific way of configuring speaker placement on the baffle am I correct. I'm obsessing over this and of the design. I have a wife to deal with.

 

[jelly_bean]

No need to really obsess over the baffle. I did for a while and made a few of them before I found that I couldn't really tell much of a difference. If you are using a tweeter, one thing I found beneficial was to place the tweeter close to the mid/full range driver on the baffle (and mirror imaged). I don't know if it was just my brain telling me it was better, but my idea was that the closer they are to each other, the closer they are to a point source.

Plus, I sit fairly close to them when I pull them from the walls.

 

[mkane]

starting here, sort of

 

[mkane]

And what to do with all my room treatments. My research tells me OB like reflective surfaces.

 

[evsentry3]

And what to do with all my room treatments. My research tells me OB like reflective surfaces.

I use room treatments with my OB. The question is how many & where?

I do not try to do a total absorbing thing behind. I find that further off to the sides behind, towards the corners, works well. And I've always tried to have nothing in the center for equipment and instead use a single panel to the middle. Something soft center instead of reflective really helps open up the soundstage. Try something temporary if necessary to experiment. So I've found on a wide enough front wall that about three 2 X 4 ft OC panels work well.

All that said, the way I'm setup now and for the foreseeable future, I've got a bank of window behind. I use normal blinds behind, turned partway closed and partway down and use a heavy curtains pulled to the sides. Three side by side windows framed by curtains. So effectively four curtains bunched up columns to about 7ft high and the header across. So that adds some absorbing and some form of diffraction from what would otherwise be highly reflective glass surfaces.

The rest of the room I use good 2 X 4 ft absorbers to break up wall surfaces and some corner treatments. The trick as always is to use enough and not too much. Not all the same everywhere is good. And in normal OB dipolar fashion, get those speakers out and away from that front of the wall.

EV3

 

[mkane]

Here's where I'm at for treatments. Bass traps and 1- 2x4 in between. Side walls have 2 - 2x4's. Room is 17x27. I'll give my son the Cornwalls and take the Heresy's back. These Cornwalls are going to be a tough act to follow. All the Crites mods and Athelia Audio crossovers. They are quite nice and don't mind volume.

 

[Poultrygeist]

starting here, sort of

Those look great.

 

[Poultrygeist]

A new option for driving my H-frames is this mono TPA3116 sub amp. With a 24v 3 amp power brick it makes plenty of power for two Alpha 15 woofers. How the Chinese can come up with a great sounding amp with built in crossover ( knob on the right ) for $12 is amazing. The power brick cost $10 and the Ikea picture frame case cost $1.99. What great times we live in for inexpensive audio.

 

[mkane]

Those look great but wait until I do my rendition. I kind of a wood hack but I try. the local cabinet guy has been a great help with some of my wood projects. Usually 3rd time's a charm or I've run out of patience.

 

[jelly_bean]

"starting here, sort of"

Those are the Musical Affairs open baffles. Check them out on YouTube. They have a ton of videos with different drivers. Big money stuff in somewhat simple baffles. I did the JE Labs (almost the same design) as my first go with a pair of 10 dollar 10" RCA AlNiCos. You could spend a lot more money and not be as happy as I was.

And what to do with all my room treatments. My research tells me OB like reflective surfaces.

I have floor to ceiling DIY super chunk bass traps in my smallish room and 4 DIY broadband absorbers on the first and second reflection points (found using the mirror method). I MUCH prefer the sound with my panels up. I spent a week with panels down and panels up listening to the same music. The difference in the tightness and control of the sound with the panels up was staggering. Even my wife sat down and raised her eyebrows. She never does that...She mostly rolls her eyes. Next, I'll making a "cloud" for the reflections off the ceiling and putting in a larger rug.

the wall behind the speakers is a big sliding glass door that I don't really know what to do with. I tried putting temporary panels there but thought that it killed the 3D magic I loved so much. I'll probably just hang some curtains knowing they won't really do a whole lot- Something is better than nothing I guess.

Experimenting is half the fun.

 

[jelly_bean]

A new option for driving my H-frames is this mono TPA3116 sub amp. With a 24v 3 amp power brick it makes plenty of power for two Alpha 15 woofers. How the Chinese can come up with a great sounding amp with built in crossover ( knob on the right ) for $12 is amazing. The power brick cost $10 and the Ikea picture frame case cost $1.99. What great times we live in for inexpensive audio.

I've got a TPA3116 that is supposed to show up today for me to play with when I'm home from work. Can't wait to see what all the fuss is about.

 

[Descartridge]

Hey Poultry,
I just picked up a pair of WHARFEDALE 12/FS/AL drivers.
What would you suggest as a baffle design?
Thanks.

 

[pboser]

A new option for driving my H-frames is this mono TPA3116 sub amp. With a 24v 3 amp power brick it makes plenty of power for two Alpha 15 woofers. How the Chinese can come up with a great sounding amp with built in crossover ( knob on the right ) for $12 is amazing. The power brick cost $10 and the Ikea picture frame case cost $1.99. What great times we live in for inexpensive audio.

Did it come as a mono amp with crossover, or is it your own creation?
Thanks!

 

[mkane]

My enthusiasm got the best of me, again. Got ahead of myself with a few new tools and put a 45 on the 2 - 10" holes. I was going to mount the full rangers from the front but since I have made these holes like this does it matter if there rear mounted. That chamfer was destined for the Woofers.