Grinnell or Bust

[Ron_E]

Re: Grinnell or Bust

I never had any doubt that you would finish.

Last night UE was whipping my but. It kind of fell together today. There is still some strangeness going on. The input signal is supposed to be coming in on inputs 1 & 2 but are showing up on 1 & 3 instead. I'm pretty sure they were right when I started but something changed. It will work but it's not quite right. Some settings will make the system have lots of digital hash. That's probably because I'm not doing something right.

This started Wednesday in front of our house and we're locked in from 8 to 6 every day. I'm not anywhere near ready to load tonight so I'll have to wait until they open up the street tomorrow afternoon before I can head to Grinnell.



Ron

[Ron_E]

Re: Grinnell or Bust

I thought I'd document the system I used to demo the speakers at DIY Iowa 2013 yesterday.

The computer was a system I built 4 years ago with an AMD Phenom II X4 940 Black Edition CPU, Asus M3A78-EM Motherboard, and 4GB of memory running Windows 7 with Bodzio Software's Ultimate Equalizer. The multichannel sound card was the M-Audio Delta 1010LT. There were a pair of 22 watt/channel Onkyo CR-325 compact system receivers driving the BG Neo8-S and Raal 10-70D drivers with a Crown DSi 1000 driving the Vifa NE225W-08 woofers. The source used was a Denon DVD 1920. Everything was running in analog mode. The sound card supports digital inputs but I didn't have time to set it up that way. The interconnects and speaker cable came from Lowes.

The UE was configured for crossover points at 400 and 4000 at 48db/oct LR. The woofers were high passed at 40 Hz at 18 db/oct. The F3 of the woofer was 50 Hz in the enclosure so setting the 40 Hz high pass in UE boosted the low end down to 40 and rolled it off at 18 db/oct.



This is a graph of the expected system response for each band.



I didn't have time to take real measurements of the system before I left for Grinnell but I did a rough check with some RTA software I have and when the drive levels were set relative to each other the response looked very flat up high and one speaker had a prominent null at the mid tweeter crossover point. Reversing the tweeter phase on that speaker flattened it right out. (Someone must have wired that one wrong.) Using the RTA the low end was very uneven which I attribute to room effects.

I'm thinking about calling these the cherry π's. That's supposed to be the symbol for Pi.

Someone asked if they were influenced by an early design by Infinity. They weren't. I actually took my design queues from early art deco radios.



Ron

[Ron_E]

Re: Grinnell or Bust

I managed to push the submit button before I finished my last post.

I'd like to thank everyone for all the interest in this project and all the appreciation shown for how it's turned out so far. It's been very gratifying.

If you're ever in central Iowa you're welcome to have a longer listen.

Ron

[Mark65]

Re: Grinnell or Bust

Whatever you call them, I call them AWESOME! I was absolutely floored by the sound coming out of those speakers. Great low end without being anything like boomy, crystal clear mids, and glassy, natural highs. Also, the build quality was absolutely STUNNING.

I won't feed the tag troll, but the tweeter was everything it's advertised to be, IMHO.


My hat is off to you, Sir!


Mark

[dcgold2000]

Re: Grinnell or Bust

Hi Ron,

I was at DIY and thought your speakers were phenominal. A quick check on Google shows the 1010lt sound card as unavailable. Is there an alternate that you know of?

[Ron_E]

Re: Grinnell or Bust

Hi Ron,

I was at DIY and thought your speakers were phenominal. A quick check on Google shows the 1010lt sound card as unavailable. Is there an alternate that you know of?

I got mine from Pitbull Audio. I thought they were unavailable too but Bohdan, the software author, sent me some links to vendors. http://www.pitbullaudio.com/m-audio-...al-studio.html

Ron

[dcgold2000]

Re: Grinnell or Bust

Pitbull shows out of stock as well. Is this the correct link to the software http://www.bodziosoftware.com.au/ ?

[Ron_E]

Re: Grinnell or Bust

Pitbull shows out of stock as well. Is this the correct link to the software http://www.bodziosoftware.com.au/ ?

That's the link. He gave me some Australian links but they're 50% higher than Pitbull.

http://www.velvetsystems.com/M.Audio.DELTA.1010LT.cfm

You might try E-bay.

Ron

[dcgold2000]

Re: Grinnell or Bust

Thanks Ron

[Ron_E]

Re: Grinnell or Bust

From Ebay. http://www.ebay.com/itm/M-AUDIO-DELT...item4acaf067de

Ron

[Ron_E]

Re: Grinnell or Bust

I'm finally back to working with the Cherry π's. I just took some measurements with TrueRTA of the whole system and the individual drivers.

Vifa Woofers


Neo8-s


Raal 70-10D


System


These are measured on the tweeter axis at a hair over 1M. They're doing road construction in front of our house so there's plenty of noise and room effects down low. It looks like UE is doing what it's supposed to. The high end roll off looks like the mic cal file isn't included. I'll find out when I do gated measurements later this weekend when they're not working on the street.

Ron

[[email protected]]

Re: Grinnell or Bust

that bottom one is what I heard Saturday. NICE>

[bkeane1259]

Re: Grinnell or Bust

That's a really good in-room RTA. The Cherry Pi system is the best I have heard at a DIY. It's definitely a last hurrah type of system. Will this be your new reference, Ron?

[Ron_E]

Re: Grinnell or Bust

that bottom one is what I heard Saturday. NICE>

I finally got around to making gated measurements. I can't be sure if this is what you heard but it is possible to do if the amplifier gains are set correctly. I'm not using the same amps for my measurements but I had tried to set the levels with the RTA measurements for the Grinnell demo. The gated measurements make it very easy to nail the levels precisely. The 1M measurements are good down to 250Hz with the window I used and there is no smoothing.

The acoustical distance setting is way out there in SE because of the digital delay from the UE program. I saw the same thing making measurements with Behringer's digital crossover and EQ. You have to search for the delayed impulse.

Near Field Woofer Measurement


1M System Measurement


Next up is trying to make UE more stable. It might be because i originally had a M-Audio Delta 410 card and had to switch to a Delta 1010LT card. Even though I uninstalled the 410 drivers there are 2 Delta setups in the Control Panel and UE looks like it thinks it has 2 cards.

Before I forget, I did have a 6db HP filter on the Raal comprised of a single 6.8Mf cap. I thought it wise to put some protection in front of it just in case the computer or amp tried to send some garbage it's way. I made my tweeter measurements for UE by setting the reference probe to include the filter.

:D:D:D
Ron

[Ron_E]

Re: Grinnell or Bust

That's a really good in-room RTA. The Cherry Pi system is the best I have heard at a DIY. It's definitely a last hurrah type of system. Will this be your new reference, Ron?

It is my new reference system and my last hurrah system. I bought the parts before I retired and became one of those fixed income guys. It's not cat food time but Raal's will probably be an extravagance in the future. Look for something smaller and more affordable next year.

Thanks for the compliment. Listening to them has been like having a new music collection.

Ron