OB Visaton B200 + Eminence Alpha 15s

[luigi]

Just wondering whether anyone on this forum has messed around with this combination, which has proved popular overseas?

Im thinking of getting some of the Alphas in to see how well they mate with the Visatons. If anyone has already had a lash (or tried other 15-inch drivers suitable for OB) I'd be keen to hear about their experiences.

I realise there has been a lot of info regarding Visatons in boxes here, but for DIY folk with limited tools and skills, OBs are a much simpler way of skinning the feline

Luigi

[Omegaspeedy]

luigi, I'd been keen to see how it goes for you. I love my B-200's (back in original configuration) but have also been curious of how the two way OB setup would sound. That 6moon article was good to read also.

 

Cheers James.

[luigi]

James

Which 6moons article are you referring to here?

[Omegaspeedy]

This one.......

 

http://www.6moons.com/audioreviews/ob/ob.html

 

and this one..

 

http://www.6moons.com/audioreviews/ob2/1.html

 

 

Nice reading with written findings.

 

Cheers James.

[enzedone]

Luigi

 

Did you manage to get your lightspeed up and running?

 

I have the Hawthorne Audio Augies, 15inch. not running yet.

Have you looked into those?

 

Brett

[luigi]

Hi Brett

 

No to the Lightspeed. Gave up on that.

Already have the Alpha 15s now. Just having trouble finding crossover details on the net. Looks like a cap and inductor might do it but values a bit hard to nail down.

Have some ideas about what to do with baffles, but just experimental stuff really.

Just wanted to see if I could get the 15s reasonably mated with the B200s before taking it further.

 

Cheers

 

Luigi

[enzedone]

Have you looked at Martin J Kings site.

 

I have actually emailed him regarding mine, nice guy. He was quick to answer and gave good advice. Throw him an email with your specs and see what he suggest.

 

 

 

http://www.quarter-wave.com/OBs/OB_Theory.html

 

 

Brett.

 

He has some info regarding Alpha 15A

 

I would love to hear these if you get them up and running....

[luigi]

Yup

 

Had a gander at all that OB theory. The problem is the projects mentioned all use full rangers other than the B200s so the crossover values for the low pass filter are meaningless. But I will find the data somewhere. It just means doing a lot of trolling through threads that are upwards of 200pages long...

[enzedone]

Something I have contemplated, and others have tried. Is letting them both roll off naturally.

No crossovers, but of course this brings into play other issues.

I don't know much, but was told that anything above 150hz is able to be distinguished as stereo (if you now what I mean?). Anything below that and you may as well have a mono sub setup......as your hearing want pick it up?

Maybe someone else could expand on that?

[luigi]

I believe that below about 80Hz you're not meant to be able to determine where bass is coming from, so you can park your subwoofer more or less wherever you want to and it will still seem as though it's output is coming from between the speakers. Certainly, that's how it appears in my system, despite the sub sitting jammed into a corner, to the left of the right speaker.

It is an OB 15-inch sub; these are excellent for not exciting room modes too much; ie, it doesn't seem to load up the room so the whole house is hearing the bass. Better WAF than the actual sub itself, if you ask me.

 

Dont want to try running the Alphas up too high, so will begin by using a 2.3mH coil in series and see how that pans out. I just happen to have a couple hanging around so they will do for starters. Also have some 0.8mH inductors so might try these too. I believe you can also use them together (paralleled) to get about 1.5mH, which is the value many people seem to use to get the Alphas to low pass at about 275Hz. Either way, Im in for a whole lot more noise by the sound of it; the system should be up by about 6dB overall, someone reckoned.

Luigi

[enzedone]

You must have quite a stash.........parts everywhere.

 

You are lucky with your setup, you have a nice place for your gear.

It will interesting to see how they work out for you.

[luigi]

Brett: A race to see who gets their 15s up and running first then? Heh heh. The Augies are meant to be excellent, but they're a bit too low in sensitivity for what Im wanting. MK reckons high sens woofers are a must in the OB application if you're mating them with high sens full rangers.

[enzedone]

Yes you are correct, and that is funny how Hawthorne sells them both. You would have thought that they would have matched them more closely.

7dB is a hell of a difference, which means there's a lot of playing around. That's why I went and built an active crossover. But need a decent amp around 150Watts. And that's why I'm selling my Image 416's, so I can afford to buy an amp (maybe), which still leaves me short (1 x pre-amp).

You will leave me for dead.....................:0

 

It will be interesting to here the two setups, I feel yours will sound better than my 15in duals as opposed to your B200's

[foveaux]

Hi Luigi and Enzedone

I run Hawthorne OBs with the Augies powered by a Keiga Plate amp

 

The Hawthorne coaxials are driven by my Mapltetree KT88 monoblocks PP 40w (see signature).

The sound is very 'live/organic/natural/musical' across all frequencies cf studio monitors (say) which may be more accurate (if measured) and very revealing/clinical but less involving emotionally.

My hearing cannot differentiate crossovers peaks, dips etc (age is cruel sometimes); but for me these OBs are better sounding than any of my former 'box' speakers.

Sadly, the OBs are in a small room presently, so compromised. However with plenty of space around and in front of them they get you there...every genre: rock, classical, folk, jazz, acoustic etc. and the critical midrange is terrific.

I also looked very closely at Visaton B200s when assessing OBs - they have a superb reputation for musicality too. Will follow your experiences with interest.:cool:

[enzedone]

Frankly, I think your on a win,win......

 

Luigi's current ones sound very nice indeed.

 

I too would never go back to boxed speakers.

[Owen Y]

luigi;129525 wrote:

Dont want to try running the Alphas up too high, so will begin by using a 2.3mH coil in series and see how that pans out. I just happen to have a couple hanging around so they will do for starters. Also have some 0.8mH inductors so might try these too.

Can you wind your own coils? Perhaps you can make up a multi tapped job & experiment from there. Big LF jobs of course.

[luigi]

Hi Guys

 

Well, they Visatons might have sounded nice enough then, but with the Alphas they are in a whole new league now.

 

I managed to sneak the new drivers into the house "under the radar", whipped the old 15s out of a couple of U frames, and inserted the Alphas right into the vacant spaces, same screw holes and all.

 

Cobbled up the 2.3mH inductors and all was up and running within an evening. Aint OB just the greatest?

 

Well, except for the bass.

 

Kidding; this is a blast compared with the B200s; dramatic improvement. Much more body, better defined midbass. Easier imaging. All good, and I expect this will be better in a hundred or so hours.

 

I will continue to use 15 inch sonosub OB bass for subwoofing as this means I wont have to go to dual Alphas; couldn't stand the final speaker being even bigger than it already is.

 

To my mind that's the one drawback of the dual 15 designs - its like having one, er two actually, of those temporary changing room walls in the middle of your listening room.

 

At present the U boxes sit alongside the existing baffle so this weekend will get the skill saw out and chop the existing baffles below the B200 cutout so they can sit atop the U baffles. That way I can get a grip on how to design the final solution baffle for the B200 and Alpha.

 

 

Will probably just do it simple, in a large isoceles triangle about 10 inches at the top and maybe 18 inches at the bottom. With maybe a couple of wings to support the whole thing.

 

Looking forward to listening to the new speaker. As you OB converts have already noted; there aint no going back to boxes once you've been turned.

 

Sure, bass and size are an issue, but the first is easy to sort (OB subwoofer) and there are ways around the second issue if you're prepared to mess with an OB subwoofer in the first instance.

 

Cheers

 

Luigi

[enzedone]

Dammmmm,

 

You always give a nice write up.

 

That's what I found, 15's just seem to sound 'bigger'. Compared to my Image, which I thought were great, the 15's just opened up so much more music and created more sound stage(does that sound right........I'm no writer )

[luigi]

Yes, I think you're right Brett. It's like the old saying with cars; aint no substitute for cubic inches.

 

Of course, that no longer holds true; low capacity 1.4l engines with supercharger and turbocharger bolted on now producing as much snot as a 2.5L four.

 

But we digress. It would appear that the soundstage is simply bigger in proportion to the increased area of the cones, and the midbass enhancement is the result of more air being moved.

 

It will be interesting to see how imaging changes once I get the Alpha and the B200 on one baffle. That is the one area that has been a bit of a challenge to date - pinpoint imaging requires a head in the vice seating position with the existing baffle - but the addition of the Alphas seems to have changed this already; there's a much bigger sweet spot.

 

Anyway, it's all early days yet. I really need to get my head around what will be the best (which for me means the smallest) baffle design I can come up with that works. Im in the happy position of not needing a big baffle for bass output as the separate sub covers that off anyway.

 

Luigi

[Owen Y]

Pics?

 

Please.

[luigi]

Owen

 

You jest, of course.

These are just roughies, to prove whether or not it's even worth continuing.

The Alphas are housed in two roughly made boxes with open backs.

The B200s are simply housed in a wooden baffle with a couple of wings to hold them up. they actually do look okay, from a distance.

However, I intend shortly to put B200s and Alphas in a single baffle, and I can throwup a pic of those once done. Hopefully they will be a bit better than barf worthy.

L

[luigi]

Things have progressed apace.

ditched my old OB frame and cut out a couple of circles in some new baffles I found in a furniture factory bin.

 

Had problems with imaging that was head in a vice stuff with the old baffle. turns out it was the baffle causing this- duh, what else would it have been? - because the new baffle, which is essentially just a piece of MDF with a finish you'd find inside of any kitchen cupboard (flat white plastic).

 

Popped these on top of the OB boxes housing the 15 inch Alphas, messed around with a few new inductor values and good god, they're good.

 

Never heard OB so natural and musical. The imaging is ideal, the staging huge and the system actually sounds like a system, doing a very decent rendition of bass as well. Dont need the sub except for films. Happy, oh yes, we are. She's not but then never is. A proper baffle next.

Luigi

[Papa Hemi]

Didn't happen unless we see the pics bay!

[luigi]

Picture a box with a 15 inch driver in it, and a piece of wood sitting on top, with an 8 inch full range driver. That's it; you just don't need photos for this.

Besides, its proto only, just to test that the system actually works. The final bit involves building a proper baffle, that will house both drivers. This will for sure include a couple of H frame boxes for the 15s; they sound good in the boxes they're in so Im not going to mess with that. The H frame offers slightly better protection for the 15 inch driver than a U frame, which has the driver out the front. They're only about 5 inches off the floor, so any stray feet could easily take out the cone. In an H frame, the drivers sit back inside the box, right in the middle, making them less vulnerable.

Once the baffles are done, then some pics, for sure. Right now, Im just enjoying how good the things sound. They're the kind of speakers that just seem to kind of get out of their own way and play music. Now I see what everyone meant about the synergy between the B200 and the Alpha 15s.

Luigi

[luigi]

Foveaux

Those coaxial Hawthornes look almost identical to the Eminence Alphas Im using. What is the tweeter they use?