Completed 10" Mid-Range Driver from Previous Post

[Mark DeArman]

Well I have completed the 10" mid-range driver I spoke about in the previous post I made. The post was regarding three way and four way systems.

Prelim testing shows 700W AES 250-2kHz for 24Hr and 100dBSPL@1000Hz sensitivity 1W@1M adjusted for Z. Not sure what the actual power handling is yet, it could be much greater than 700W, I just chose that as a starting place and didn't do a incremental test.

The goal was sub 1% THD+n over the operating range at 6dbV above sensitivity voltage. And that goal was achieved. Plus the better pattern control by having the diaphragm made of a high stiffness composite.

Not really sure what great use there is for a 10" mid-range, any thoughts? Personally I think an 8" mid high is the best.

EDIT.

Well after looking at the LG fp2600 docs it looks like @8Ohm nominal bridged they were 1600W max. So the two ~16Ohm drivers would have been more about 800W a piece at 0dB on the amp. during my test. I do have a I-V monitor which I will put on them later on and run a better test.

 

[Tim Weaver]

Re: Completed 10" Mid-Range Driver from Previous Post

Is the cone flat or cone shaped? It's hard to tell in the pic. Also what is it made of?


Cool project!

 

[Mark DeArman]

Re: Completed 10" Mid-Range Driver from Previous Post

It's a hyperbola made of UV resistant flexible epoxy resin coated Kevlar sheets with a closed cell foam core. The cone weight is about 9g. Total Mms was 20g including the spider and surround and coil. The one in the picture is a prototype, the final has a much smaller magnet structure and shorter coil. The cold measurement on the new magnet was 16000 Gauss. The shorter coil I had made from Aluminum and smaller wire gauge to make it 16Ohm and up the BL product.

It has been an interesting 2 year project experimenting with materials which keep the distortion low, but I'm sure there is a lot more to to be discovered. Aerospace products are just such a pain to get a hold of in small enough quantities to experiment with.

EDIT... Mms is 30g, Hah I wish it was 20g that would be awesome! I need some of those carbon nano-tubes or something to wind the coil with.

 

[Kevin Unger]

Re: Completed 10" Mid-Range Driver from Previous Post

It's a hyperbola made of UV resistant flexible epoxy resin coated Kevlar sheets with a closed cell foam core. The cone weight is about 9g. Total Mms was 20g including the spider and surround and coil. The one in the picture is a prototype, the final has a much smaller magnet structure and shorter coil. The cold measurement on the new magnet was 16000 Gauss. The shorter coil I had made from Aluminum and smaller wire gauge to make it 16Ohm and up the BL product.

It has been an interesting 2 year project experimenting with materials which keep the distortion low, but I'm sure there is a lot more to to be discovered. Aerospace products are just such a pain to get a hold of in small enough quantities to experiment with.

EDIT... Mms is 30g, Hah I wish it was 20g that would be awesome! I need some of those carbon nano-tubes or something to wind the coil with.

Great project, DIY to the extreme.

I agree on the aerospace bit. I REALLY miss working in that particular industry, even just being a grunt. So much cool scrapes "thrown" out.

 

[Mark DeArman]

Re: Completed 10" Mid-Range Driver from Previous Post

Putting it all together. New woofer with the 10" and dual BC DE920. Everything is matched in SPL pretty good now. The next steps, the horn and phase plug/edge cover for the 10s. Ran the mid low for an hour with two channels of fp6400 0dB with 2.8Ohm DC load for the 15"s and 5.2Ohm for the 10". Typical danceclub music signal with no limiters. Nothing fell apart ;-), that's always good.

When I was testing the 15" before it was with a fp14000 and I couldn't get them to smoke in a parallel loading configuration with pink noise 80Hz-500Hz. It seemed that if the coil equilibrium temperature was around 200degC nothing really bad would happen. With the fp14000 in bridge mode edging the temp up to 220-240degC small defects could go hot and melt typical non-toxic solder joints. When I replaced it with Silver nickel cadmium solder this problem went away. Both the 10 and the 15 in the 24 hour bandlimited pinknoise test had a equilibrium temp of around 100degC in the box at full power. The voltage set points for the test were ~800W @ 1000Hz for for the 10" and ~2000W @ 200Hz for the 15". These power levels just chosen as good numbers.

I guess the garage project is getting to the point of designing a product.

 

[Chris Davis]

Re: Completed 10" Mid-Range Driver from Previous Post

Well I have completed the 10" mid-range driver I spoke about in the previous post I made. The post was regarding three way and four way systems.

Prelim testing shows 700W AES 250-2kHz for 24Hr and 100dBSPL@1000Hz sensitivity 1W@1M adjusted for Z. Not sure what the actual power handling is yet, it could be much greater than 700W, I just chose that as a starting place and didn't do a incremental test.

The goal was sub 1% THD+n over the operating range at 6dbV above sensitivity voltage. And that goal was achieved. Plus the better pattern control by having the diaphragm made of a high stiffness composite.

Not really sure what great use there is for a 10" mid-range, any thoughts? Personally I think an 8" mid high is the best.

EDIT.

Well after looking at the LG fp2600 docs it looks like @8Ohm nominal bridged they were 1600W max. So the two ~16Ohm drivers would have been more about 800W a piece at 0dB on the amp. during my test. I do have a I-V monitor which I will put on them later on and run a better test.

More surface area/more power handling? In the back of a large horn and behind a phase plug, like an older EAW KF series point source cab. Front loaded, a 10" would just be a bit more beamy and thus require the tweeter to go lower. Not as much of a deal-breaker as a 12" or 15" mid though. :twisted:
Looks neat!

 

[Mark DeArman]

Re: Completed 10" Mid-Range Driver from Previous Post

More surface area/more power handling? In the back of a large horn and behind a phase plug, like an older EAW KF series point source cab. Front loaded, a 10" would just be a bit more beamy and thus require the tweeter to go lower. Not as much of a deal-breaker as a 12" or 15" mid though. :twisted:
Looks neat!

Yeah I wish I could get down and plot these on the spherical plotter like I did with the 8"ers.

 

[Mark DeArman]

Re: Completed 10" Mid-Range Driver from Previous Post

I finally did a half-full setup with a revised version of the mid-range above. Was able to make some basket modifications to remove the hole in the response curve (700-900Hz) in the previous post. Worked pretty well, basic EQ didn't take long to get reasonable results with the 14 box array. Used an LM26 into six fp10000q. I'll post the measurements later on.