Bottleneck speaker competition (MD/VA/DC/DE/PA)

[dbishopbliss]

...I thought she sounded a bit like how a balloon sounds when you let the air out quickly.

She currently has a song on the radio that has so much auto-tune on it that it sounds like a video game.  Maybe that is what she is going for.

With regard to the rules... As long as its under the price limit, can you augment the driver with a woofer instead of a tweeter?  I have seen people doing this with full range drivers and was curious how it sounds.

And I vote for $150 cost limit.  This should give enough flexibility for a wide variety of designs while keeping out of the really exotic territory and also not having to bottom feed too much if someone decides to go with a multiple driver design.

[castlesteve]

  I have no problem with the woofer idea as long as a fullrange driver is kept in the mix. I vote for $175.00 as i`ve been looking at the fullrange prices and they have increased a lot due to the shortage of neo magnets.

[dbishopbliss]

Why not a nice round $200.  This will allow for all but the most exotic full range drivers, but still leave room for BSC filters, etc.

[castlesteve]

 

Why not a nice round $200.  This will allow for all but the most exotic full range drivers, but still leave room for BSC filters, etc.

  That's good with me. We should see a nice wide selection of drivers with that limit.

[RayP]

I'm a little puzzled by what is being proposed with the full range driver augmented by a separate woofer and or tweeter which to my mind turns into a three way. There's nothing wrong with that of course. I do this at home with the xovers at 80 hz  and 7 khz. However, I would prefer something simpler such as just a full rangers though I have something in mind that is a 3 way.

In our past two competitions, we have had constrictions (6V6, russian tube) as well as $$ limit and container that make the design process more challenging. So far I am only seeing the $$ limit as the constriction.

Two possible constrictions are to nominate the power rating of the amp to be used and which room we will hold the competition. Let's say it's Steve's room. I suspect you would need more amplifier power in it than Fritz's room. John's 45 amp would be out of the question for the inefficient entries, even the 6V6 would probably be marginal. So let's start thinking about the room and amp we will use before we go too much further.

Other ideas for constrictions would be welcome and something for us to think about.

ray

[Paul Joppa]

Not that there's more than the slimmest chance I'll be able to make it, but an idea would be to allow either a tweeter or a woofer but not both. A fullranger by itself is pretty constrained to the 6"-8" range if it is to have a balanced spectrum, and thousands of designs have been developed and are out there on the web. But making the choice between HF and LF augmentation is a more interesting design challenge which has not been much explored.

... Except of course for the standard 8"-12" woofer with 1" tweeter which s the conventional-wisdom standard in spite of the midrange compromises. Should there be a constraint on the crossover frequency to keep it to augmentation rather than an ordinary 2-way?

[castlesteve]

 Ray,
     I think David is proposing a small fullrange driver with a bass driver to supplement the low ranges. We could restrict the cabinetry to be an original design and not a copy of someone else`s design. That would present somewhat more of a challenge to all the builders. There are all sorts of online programs to help with box design. i think that $200.00 and requiring an original design would be a sufficient competition. i suspect that a good fullrange unit in a well designed box with correct damping will defeat a 2 driver version due to driver quality, but we`ll see!
  

[RayP]

I like Paul's idea of a max of one crossover and restricted xover ranges. I suppose we could just say the xover should not be in the 300 to 5000 range or whatever range we come up with.

I also like Steve's suggestion of an original design but I doubt that any of us could come up with a totally new design. Perhaps we could redefine the suggestion to 'a design that does not have a web site with plans that you just copy'. You could take the concept but use different speakers. For example, you could take the MLK open baffle on a H frame and use a different woofer and full ranger from what MLK has already used.
http://www.quarter-wave.com/Project08/Project08.html

ray

[dbishopbliss]

Ray just posted before me, but we were thinking along the same lines...

I was proposing either an added tweeter or woofer, but not both.  This would allow for something similar to the Jim Griffin Jordan/Aurum Cantus design or the Martin King Jordan/Goldwood design.  That said, I think that we should require entries to be an original design.  I don't think a Fostex speaker with Fountek tweeter is the same design as the Jordan/Aurum Cantus. 

I think requiring folks to build their own enclosure might put some people out of the competition so I think we should allow people to purchase pre-assembled cabinets.

So, how about this:

- full range driver 4" or smaller
- can be augmented on the high end or low end, but not both
- must be an original design
- pre-built enclosures are ok
- total cost of drivers, crossover components, damping material, input jacks must be less than $200

[castlesteve]

  Are we agreed on this yet? Does anyone else have any more input?

[RayP]

I'm fine with it and I know what I will attempt to build.

ray

[castlesteve]

I'm fine with it and I know what I will attempt to build.

ray

  Me too. I`m going with something simple but hopefully good sounding. i just ordered the drivers!

[dbishopbliss]

I think we are close enough... I'm not going to do anything that would be different from any of the guidelines that have been proposed.  Don't really know what I will build yet.  Right now, I'm building a 1960's Marshall 4x12 cabinet replica for a friend.

[castlesteve]

  Did we stipulate a meet date? Hopefully some time in September or later. Most of these fullrange drivers do sound better with some time on them. If you like we can do the meet at my place.

[dbishopbliss]

Are you suggesting September for the competition or for a meeting to finalize the rules?  I'm hoping to learn about box/baffle design, crossovers, etc.  I'm not sure how much I will really learn in such a short time.