[Browntrout]

Hello, I wish to start experimenting with making my own speakers and in particular an open baffle design. Where should I begin?
  I presume the simpler the better for I have not heard an open baffle nor am I likely to get to hear some at any point. I was thinking Lowthers in a simple but large piece of wood reaching from just above the floor to just below the ceiling so the drivers would be equal distance from the floor and the ceiling. Any and all suggestions welcome. ( I have 13 Watts of SET power to play with.)

[MJK]

Where should I begin?

Simulations. In an afternoon you can run enough experimental configurations and eliminate a large number of options helping you focus on something that will have a chance of working. Don't spend any money on drivers until you have a plan and an expected result.

Martin

[Browntrout]

Hello MJK and thankyou for the reply. I have just read some of your website relating to open-baffle design, the two way passive section and found it very interesting and well written.
   Would I be correct that the actual physical size of the baffle is the limiting factor in a design? (If I wish to obtain the greatest realism across the widest frequency range).
   The largest baffle I could accomadate in my listening room (also my lounge) would be  around 40" wide and 90" tall (height being limited by the ceiling but the width could be increased by six inches or so if needed).
    My current speakers are 93db efficiency (Cabasse Farella 401) and I would like to hear what my system can do with a higher efficiency speaker say 95db, 97db or more. Which other parameters do I need to set before I begin simulations? Thanks.

[MJK]

I think you really want to go with a two way. I do not believe a single driver will meet your expectations. At those efficiency levels I would look at two Eminence Alpha 15A drivers up to 100 or 200 Hz and then a full range driver for approximately 200 Hz and above. If you want to use a Lowther there is a thread below which discussed just such a design.

[Browntrout]

Thanks again for the information. I was hoping to start as simple as possible to hear what a full range open-baffle speaker sounded like then possibly use the same full range driver in other more complicated designs as I learned about the sound of things and improved my woodworking skills.
   If I was to start with the simplest type of speaker which driver would you recommend? I just feel multiple drivers and a crossover might be a bit too much for a first build/learning exercise.

[gooberdude]

I agree with MJK that a quality 2 way system might give you the best initial experience...  Otherwise, you might get trapped
with a sound that always leaves you craving for more and wondering what you are missing.   This gets frustrating and expensive quickly.


You won't go wrong digesting and following the good advice of folks around here, we've all been where you are now.

[Russell Dawkins]

MJK, I am curious at to why you would recommend the Eminence Alpha 15As in this case instead of the Goldwood 18s you use in your 20-20k design.

Russell

[MJK]

MJK, I am curious at to why you would recommend the Eminence Alpha 15As in this case instead of the Goldwood 18s you use in your 20-20k design.

The original question concerned a flat OB of some width up to 40 inches. For an OB the higher Qts of the Eminence Alpha 15A is more important then the lower fs of the Goldwood GW-1858. Both will start rolling off at 100 Hz and the Goldwood will be down quite a bit at 50 Hz even in a fairly wide baffle. The higher Qts of the Eminence will offset some of the OB roll-off so that the bass will be stronger at 50 Hz. In either case, you will not get bass to go much below 50 Hz.

Martin

[dewar]

Brountrout,

You will not need to go near a crossover. A plate amp or Reckhorn with built in XO can drive your Alpha/Augie, and you will can run your Lowther/Visaton B200/ Forstex etc without any crossover.

If you want to play around with OB then the above are good choices, they are all good drivers but not so good that after a while you wont be tempted to try improve them somehow. If you want your first fullrange OB to be your last I would volunteer the Bastanis Prometheus with Hawthorne Augie in the bass, the end of the road for me I think.

[TerryO]

Hello, I wish to start experimenting with making my own speakers and in particular an open baffle design. Where should I begin?
  I presume the simpler the better for I have not heard an open baffle nor am I likely to get to hear some at any point. I was thinking Lowthers in a simple but large piece of wood reaching from just above the floor to just below the ceiling so the drivers would be equal distance from the floor and the ceiling. Any and all suggestions welcome. ( I have 13 Watts of SET power to play with.)

Trout,
I'll leave the final word on drivers to those that have used them, BUT whatever you end up with, do not place them equal distance between the floor and the ceiling as you'll be creating some real problems with both floor and ceiling bounce combining for some exaggerated room modes that will affect the sound within your room. In fact, you want to avoid "even multiples" of the distances. You might try placing the midrange/tweeter at approximately your seated ear level and calculate the relative distances from there, adjusting them slightly to achieve an odd ratio.
I'm pretty tired tonight, so I hope this makes sense

Best Regards,
TerryO

[Browntrout]

Once again thankyou for your relies. I think I have enough to be going on with, plenty of websites to read and frequency graphs to peer at. After speaking with a chap at Supravox, who has recommneded one of their drivers (which is designed for open-baffle use) and given dimensions for the baffle (1.6m wide by 2m high) I might well go with this as a single driver open-baffle start then perhaps add a tweeter/supertweeter later.
   I have often wondered why speakers were set up to be symetrical in the horizontal plane but not in the vertical, hence the thinking about placing the drivers at the mid point between floor and ceiling. Thanks for clearing that up for me TerryO.