BillFitzmaurice.info

Going to be building some sla
LR and curved center and surrounds soon. Looking at the recommended drivers and was wondering if there's any difference between the pioneer and goldwood driver other than about $8.00 a driver? I am also interested in using the Dayton driver that is about the same price as the pioneer driver. Any recommendations?

The specs matter, the price and brand doesn't. Don't be afraid to search around for other options as well. I built the originals with NSB (no stinking badges!) drivers of unknown origin that cost around a dollar each.

At $4.90 each, I've been considering these.

Those look very good, and the price is right. I'd scoop those up if I was considering a build.

Bill Fitzmaurice wrote: ↑Fri Jan 14, 2022 6:10 pm Those look very good, and the price is right. I'd scoop those up if I was considering a build.

No problem with 'em being 16ohm? Plans are pretty specific to use 8ohm. I couldn't figure out how to get 4 16ohm drivers down to an 8ohm load....

That's a good point Bruce, for a 4 driver SLA. Works out fine for an 8 driver center or TLAH. Not sure I'd be too-too worried about a 4ohm main. It is a valid point and consideration.

The slight hitch I saw was that their edge to edge diameter is 4.75" and the plans specify not more than 4.5" edge to edge.

Or better yet: floor to ceiling!

Bruce Weldy wrote: ↑Fri Jan 14, 2022 6:48 pm I couldn't figure out how to get 4 16ohm drivers down to an 8ohm load....

You can't. It would require recalculating the crossover component values to run at either 4 or 16 ohms, but that's not at all difficult. With respect to the low pass to go from 8 to 4 ohms you halve the coil values and double the cap value. To go from 8 to 16 ohms double the coil values and halve the cap value.

Bill, in looking at the Sketchup files, it looks as though those drivers 4¾" overall diameter could work okay for the SLA center with tweeters rear mounted, would probably work okay in a TLAH with 8 drivers, but the height of the SLA's wouldn't accommodate them without modifying the cab dimensions or trimming an eighth off the edges of the driver. Neither of those options seems like a deal breaker, I wouldn't think.

Would you recommend either of those options in particular over the other, or just suggest looking for a different driver of the correct dimensions?

I built my SLA's with 5" drivers similar in style and price to Seth's link. I didn't need to modify the crossovers, but I did have to redesign the cabs (which was against the plans). It was a total pain in the butt and I'll never do it again. At the time I was working with an extremely tight budget. My advice it to use the recommend parts or find some with the same specs as to not alter the plans any.

Making the box large enough to accommodate 4 3/4" diameter drivers is no biggy, since it's a sealed cab and you don't have to be concerned with upsetting the tuning. OTOH looking at the backside of those drivers I can see that it wouldn't be difficult to trim them with an abrasive blade, just being careful to wrap the motor well to keep metal sawdust off the magnet. I'd even use tin snips if using a grille.

Bill Fitzmaurice wrote: ↑Sat Jan 15, 2022 12:16 pm Making the box large enough to accommodate 4 3/4" diameter drivers is no biggy, since it's a sealed cab and you don't have to be concerned with upsetting the tuning. OTOH looking at the backside of those drivers I can see that it wouldn't be difficult to trim them with an abrasive blade, just being careful to wrap the motor well to keep metal sawdust off the magnet. I'd even use tin snips if using a grille.

Thanks for the feedback and great advice about wrapping the motor. I'd have definitely learned that the hard way.

Well, I'm adding 2 TLAH's, an 8 driver SLA center, and two SLA surrounds to my list of future builds. I went ahead, pulled the trigger, and ordered 36 of those drivers. 8 more drivers than the 28 I need for the project put me at the next qty price break and only cost an extra $20 ($2.50 per spare driver). I'm thinking I'd rather have them and not need them, than need them and not be able to find a matching replacement sometime down the road. Or maybe I'll make a pair of 4 driver SLA's with them. We'll see.

Sanity check. After these arrive, my parts shelf will have four Delta 12LFA's, four 3012LF's, four S2012's, eight PRV Neo 8's, two PRV Neo 6's, an Alpha 6A, a BP102, an MCM 8, a box of about 80 piezo's... and 36 4" drivers. I've really gotta stop buying and start building

Seth wrote: ↑Sat Jan 15, 2022 1:34 pm I've really gotta stop buying and start building

Yup.

I have used a ton of these drivers in other projects.

https://www.parts-express.com/4-Treated ... hm-299-320

These drivers perform very well.

The question is:

They are 16 ohm which work good in multiples of 2, 3, or 8 drivers with most HT amps but the curved SLA option would require 8 drivers to get to 8 ohms, but the curved SLA plans call for 9 drivers or 6 drivers. What difference in the angles of the front baffle sides would be required to only use 8 baffles in the front, instead of 9?

caddylackn wrote: ↑Tue Jan 18, 2022 2:00 pm What difference in the angles of the front baffle sides would be required to only use 8 baffles in the front, instead of 9?

A post made in another thread...

Bill Fitzmaurice wrote: ↑Sun Jul 18, 2021 3:01 pm Use 8 drivers. Wiring four 16 ohm drivers in parallel is 4 ohms, wiring two sets of those in series gives you 8 ohms. To make an 8 driver curve array make the top and bottom 42 inches wide, the back is 41 inches wide. The baffle end segments are still 2" wide but the end angle is 12 degrees. Otherwise everything else is the same as the 9 driver version.