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lets bring back sub testing - Page 2

post #31 of 479
Ed Mullen was the most structured and well versed reviewer I remember. Makes sense he's at SVSound.
post #32 of 479
Thread Starter 
Talking with Ricci some more looks like we are going to shoot for the weekend of October 9th for this. Anyone in the middle tn or Louisville area wants your stuff tested, I guess I will check with Josh, but maybe even commercially made subs, let us know and we will try and get them tested.
post #33 of 479
Depending on where it's held, I would be interested in being present. I have no knowledge, but could stand to learn from you guys. I'll be watching the thread. I think I'm about 4 hours from Murfreesboro.
post #34 of 479
Thread Starter 
Sorry Tony, will probably need to make that about 7 hours from you. It'll be in the Louisville area. I'm driving up to Ricci's area and he has a space picked out that will work.
post #35 of 479
ahh, okay. I'm out.
post #36 of 479
Quote:
Originally Posted by brandonnash View Post

Talking with Ricci some more looks like we are going to shoot for the weekend of October 9th for this. Anyone in the middle tn or Louisville area wants your stuff tested, I guess I will check with Josh, but maybe even commercially made subs, let us know and we will try and get them tested.

I've always wanted to see my RLp18 tested. Ilkka was supposed to do it but everyone wanted to see how great the 5400 is. Not sure how I'd get this to you all the way over there. Shipping would be expensive as all hell.
post #37 of 479
Brandon / Ricci: is this still on? I was thinking for some reason it was on the 7th.... but I will be down in Chicago the week of the 5th on- so I may be able to make it down, depending on how long I can take off of work.

Ricci, you have an email.
post #38 of 479
Yeah. I have a crazy amount of stuff going on right now but it will happen. Shooting for the 9th and maybe the 10th if another day is needed for the actual tests. Most of the gear is together and ready to go. The next week and a half is lining out the details.
post #39 of 479
Quote:
Originally Posted by brandonnash View Post

Its been way too long since illka has been out of picture and I believe we should bring back some sub testing. Let's try to find someone who has the equipment and space to do it. Volunteers? I know Ricci said something about trying to get the equipment together to do it but don't know how much space he has. So if anyone has any ideas just fire away.

If by space you mean a room in which to make measurements, you're not measuring the sub, but the room. It's better to measure subs without the room interfering, as Keith Yates has done, such as in this article. He's written extensively on the subject.
post #40 of 479
i don't have anything to bring, yeah that hurts but its job related. i'm game for helping out however i can. should i shoot down or would i just be a fifth wheel?
post #41 of 479
Quote:
Originally Posted by Roger Dressler View Post

If by space you mean a room in which to make measurements, you're not measuring the sub, but the room. It's better to measure subs without the room interfering, as Keith Yates has done, such as in this article. He's written extensively on the subject.

What Brandon is referring too is space as in open, outside area that will not be a problem with neighbors.
post #42 of 479
I have the space in an industrial area. I am slightly concerned with the amount of background noise though. I believe since most of the tests will be loud and pushing the subs quite hard that it should be fine. Might increase the apparent distortion levels a bit. I'm going to get a capture of the spectrum and level in the next few days.

I don't care if you guys want to try to be there. So far it looks like Brandon, possibly mjg100 and Mike Hurd. Ltd02 its up to you. I figure I'll be doing all of the running of things since I know what the plan is. Help moving around all of these cabs will be appreciated.
post #43 of 479
Have you guys posted in the subwoofer forum asking for comercial subs ? I would be awesome to get some new ones there.
post #44 of 479
Thread Starter 
Going to keep it local to what we have on hand unless something very good comes along. Ricci already has 10 or more subs he will test plus any that I may bring. If I can get a good design down and have some free time I am going to try and get a simple 25 hz horn done. But its close so I probably won't get around to it.


Ricci, will shoot you a text in a bit.
post #45 of 479
Whoops! The main testing is the 8th on Friday not the 9th. It's always been planned as Friday with a spill over into Saturday if needed. Hope I didn't confuse anyone.

Penn,
I was trying to keep this fairly covert as I didn't want too many more subs this time out. I'm not sure how much time each will take or what hiccups will occur throughout the day. I don't want to bite off more than I can chew. I would go for having a tht or a labsub there but I'm not worried about smaller commercial type subs for this round.
post #46 of 479
Quote:
Originally Posted by mjg100 View Post

What Brandon is referring too is space as in open, outside area that will not be a problem with neighbors.

Thanks for clarifying! Looking forward to the tests.
post #47 of 479
Great thread... Not sure how I can help but I'd definitely like to be part of it just for the learning process.
post #48 of 479
How did it go this weekend?
post #49 of 479
Thread Starter 
Unfortunately I didn't get to make it. I texted with Ricci a bit yesterday and he toughed it out alone and was still going late yesterday afternoon. I believe he started on Friday, or at least that was the plan. Sure we will have some updates soon but I have a feeling the amount of testing he was doing will take some time to compile all the info.
post #50 of 479
Yeah, he wanted to do the majority on Friday. I was more interested in how things went. It's too bad he had to tough it out alone.

I am well aware of the headache he is going to have when sorting all that info out. Making it all easily assessable will be a challenge itself. We have been talking about it for some time now, and I think he knew what he was stepping into.
post #51 of 479
Tests are done on the subs as of about 8pm Sunday. Started Friday at about 10:30am. There was definitely a learning and comfortability curve. By Sunday I started to get the flow of both setup and the various steps down to a much smoother process. If there is a next time I'll feel much more confident. There was a very hefty dose of Murphy's law in effect throughout the weekend. Too much to go into in detail. By Saturday night I was in the mindset of expecting problems. Worked well. Gotta roll with punches. BTW my respect level for those that take the time and effort to collect data to share with others in an endeavor such as this has been multiplied 12 fold. Its a LOT of work.

CEA2010 testing is a PITA! It probably takes roughly 2-3 hours to setup and complete a test for one sub and CEA2010 is a very large chunk of it. Bleck!

I have a huge amount of data to compile. It'll probably be weeks before I get that done, so anyone expecting to see anything soon... Sorry.


One more thing. I have officially broken my first heavy duty sub. The only casualty of the whole field. I made a XXX bottom the suspension so hard it broke the triple joint and ripped the vc leads. Off to the factory for a recone it goes. Ive never seen a cone move like that. I'd guess that the tech I talked to at RE was right and the suspension is fully stretched out at about 5.25" p2p. I sat there and watched it happen. Looked more like 6". Couldnt abort the sweep quick enough. It was horrible to behold. Amazingly the vc still didn't contact the back plate! This was completely my fault. It got ALL that a ballz out clipped to the max Crest 8002 has, below its tuning in the ported cab. Right about 8-9hz is where it went bad I believe. I saved a copy of the signal which I will post and explain tomorrow.

It might be hard to believe but I have never damaged a bass driver to where it was non operational before. I guess I'm either lucky or I just percieve the indicators well.
post #52 of 479
Crap, all weekend? Yeah, CEA is a pain.

I have a light week coming up. If there is any way I can help with the data shuffle/correlating let me know. If you are like me the data is all jumbled up, and no one but the one who made the mess could do anything with it.

Seriously though, if I can help let me know.
post #53 of 479
Crap dude, I would have loved to see that woofer launch. You gonna do another subwoofer marathon next weekend?

I'm looking forward to the data.
post #54 of 479
I appreciate the offer Soho but I'm not even exactly sure what all I have or how to best extract and present it yet. I think you would probably just see a random pile of measurements with cryptic labels and need a rosetta stone to decipher them.

I'm not even sure where the data will be presented yet. I'm working on that.
post #55 of 479
Thanks for all of your efforts Ricci. Sorry to hear about your mishap. That Crest definitely packs some heat. But I can help wit dat - if you want I'll trade you a Macro Tech with a couple hundred watts per channel fewer - it's a little easier on sub drivers....
post #56 of 479
Quote:
Originally Posted by villastrangiato View Post

That Crest definitely packs some heat. But I can help wit dat - if you want I'll trade you a Macro Tech with a couple hundred watts per channel fewer - it's a little easier on sub drivers....


Good luck with that offer - I can likely sum up both our feelings about the 8002's.... In 5 words !!!!





Good lord Josh, I thought I was bad.... sorry to hear about the XXX, and I thought they were indestructible....
post #57 of 479
LOL!!!

Hey, can't blame me for tryin'..........


I am curious though about the circuit topology of the 200 series though. I've never owned a Crest - have heard nothing but raves about them. They specify in their cut sheets the use of "high speed" mosfets in the finals. I was curious if this was also coupled with a wide bandwidth driver stage(s) and what kind of slewing rates are generated overall. I've had a fair amount of experience with early Kenwood high speed stuff (L07, L07M II, KA 907, and KR8050) which were great sounding but plagued with self destruction and stability issues as they got older.
post #58 of 479
blown motors are a common occurance at the track.

nobody likes to see one die, but as you know it is the price for pushing the limits of performance.

i'm very curious how your ported b&c's performed. given the amount of data...i suspect that i'll just have to sit on my hands for a while.
post #59 of 479
Quote:
Originally Posted by Warpdrv View Post

Good lord Josh, I thought I was bad.... sorry to hear about the XXX, and I thought they were indestructible....

Hey I was beginning to think they were too. Bosso had mentioned something about alien adhesives being used back long ago... Apparently after exposure to our earthly atmospheric conditions it will degrade over time. Seriously though this driver had been through the ringer so many times I'm surprised it was still alive anyway.

Que taps...











Here is the signal that got input which is below the port tuning.



Can't think of any sub that is going to survive that coming clipped out of a 4kw bridged pro amp.

Here's what happened. I had mistakenly assumed that I wouldn't need a hpf for this cab since it was tuned to 11hz and the tests would only be from 10hz up. What I didn't count on was that every program I was using to generate the compression and FR sweeps still starts the sweep down near 1-2hz even if only measuring from 10hz up, so all of that crazy below tuning sine content was limiting the compression sweep levels prematurely for this cab. I was trying to quickly rig up as low of a hpf in the DCX2496 as I could on the fly with various EQ functions and I had one down around 12hz worked up. I wanted it closer to 10hz as I was chopping off the low end a little prematurely so I was attempting to work towards that. Lets just say it involved a monumental amount of 20hz shelving boost combined with a Butterworth 48db octave hpf at 20hz, etc...Somehow I switched the 48db BW hpf to 24db on accident and it produced the purple trace in the above graph where what I had been using was similar to the green one. Started a sweep off and bbbbffffffFFFFF...whump...whuMP...WHUMP...WHUMP...SCRIITCHH!




Anyway I did work up an effective 12.5hz Butterworth 24db octave hpf with about 4 filters in the end.

post #60 of 479
So what subs were tested again?
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