Yet another 1st open baffle project

[markjandrews]

Hi, everyone. I did the politic thing and checked similar threads before starting a new one, but the old threads aren't quite like this.

I hope these words are not mutually-exclusive, but I'd like to create a pair of desktop, open-baffle loudspeakers. I'm using as many found-parts as possible - scrap lumber and a pair of woofers a buddy of mine gave me. The woofers, as fate usually has it, are new-old-stock and I can't find T/S parameters to save my life:

- Yamaha 8" 'sub woofer'
- Model number YCS-800
- Nominal input 100 watts (which I take to mean 50 watts RMS clean at best, probably less).
- 4 ohms

I can't find my trusty multimeter so I can't measure the actual DC resistance or inductance. These drivers are 8 inches in diameter, but in an oval frame - for a car, don't ya know. I might try and take a couple snapshots and upload them if that's helpful. Beats me what I'll drive them with. I have an old, but servicable KLH Model 51 at the office that I use for a headphone amp. I'd eventually like to hook these up to one of those nifty 50 watt, Class T amps from Parts Express.

As for a baffle, I thought I'd start w/1 ft wide by 2 ft tall. And what the heck to use for a full range driver? I have no idea where to start except that I favor something I can salvage and re-cycle into a new project.

Just to be completely dangerous I found, downloaded and have installed "The Edge" by Tolvan Data. I'm a long ways away from knowing how to use this software, and a long way away from designing a Zobel, baffle step and bass drop compensation filters.

Thanks in advance for your time and help. If your best advice is "Scrap those old car subs" I'm totally okay with that. So, for that matter, is The Funding Committee (aka my wife).

[chris661]

Old car subs could well be designed for free-air use (ie, leaky door panels etc), so they could be worth a go.

Apart from that, I'd tend to agree that desktop and open baffle are almost exclusive. You could use the sledgehammer approach and eq the bass back in that will be lost by the small baffles. For nearfield use, that should be sufficient...

For something wide-band, try bidding on older drivers on ebay - you can get some reasonable 6" widebands for very little cash.

Photos of the drivers you have so far would be great,

- Chris.

[Nelson Pass]

Originally Posted by markjandrews

Hi, everyone.

[jrenkin]

8" - open baffle - desktop - ?
Must have a big desk....

[eyoung]

I think the 8 incher is the sub... I was thinking about using 2 4" hi-vi B4N and a small dome tweeter in a dipole arangement as a center channel (sub crossed over ~220hz)I have not done the math. As you I have a convenient piece of wood and some small speakers to rob crossovers from. The math is for baffle dimentions as there is a correlation between baffle size and frequency to prevent what is termed beaming. Sometimes you can just build it and its sounds OK, and will get you to the next level in the never ending spiral into DIY. So , just build it and if it sounds OK then great,and if it don't do the math and build something else..

BTW Welcome, Elwood

[gainphile]

I use 3" TB Fullrange.

Bookshelf open baffle with Seas 8" and Tangband Full-range

My desk is not that big.

[CLS]

For used on desk top, I suppose it's very nearfield and limited SPL. So, why not starting with naked driver? 8" might work OK within that short distance with help of the desk surface (just like floor). Of course severe EQ is still inevitable.

Please refer to my previous post here: Even Cheaper and Faster OB Trial

Don't be scared by the looks and that current feedback sort of things. I started that trial project by naked driver and EQ. A pair of 8" drivers can have basic tonal balance up to conversation level or slightly more than that (with the cones dancing hard in front of you, though ). I think this is sufficient for nearfield desk top usage.

If the SPL or bass is still not enough, then you may add any mockup baffles you want before building the final version.

[markjandrews]

I tried uploading some pictures to diyaudio, but I can't see them, even though the 'board says it got them. Instead here is a link to a photo on PicasaWeb.

Picasa Web Albums - Mark Andrews