Single sheet TH challenge

JBell
When you do your measurements are you using the driver stated 8 ohms as the reference or or you measuring the impedance of the particular driver?

I got my SS15 put together yesterday.
Turn'd it on today. (driver is from one of my Apaches so its broke in). Threw 2.83 volts
into it and measured @ 1M 110db at 100 hz. Forget which post has the results you got.
Course it is about to start raining so I probably wont get to really test it out any time soon.
 
JBell
When you do your measurements are you using the driver stated 8 ohms as the reference or or you measuring the impedance of the particular driver?

I got my SS15 put together yesterday.
Turn'd it on today. (driver is from one of my Apaches so its broke in). Threw 2.83 volts
into it and measured @ 1M 110db at 100 hz. Forget which post has the results you got.
Course it is about to start raining so I probably wont get to really test it out any time soon.

what kind meter you use to measure 2.83v? (I know my beckman isn't a "true" rms meter -- neither is fluke -- they don't deal with dc offset, but it's close)

I'm assuming you have a grin on your face right now?
 
Flip, here's my measurements and runrod's..

sounds like your 110 is between these 2??

yes, I assume nominal 8ohm and test either at 2.83v@1m or 28.3 volt@10m.

jbell measurement...Runrod1948 measurement

40hz 98.5.....40hz 101db
45hz 100.5...45hz 104db
50hz 102......50hz 108db
55hz 103.5...55hz 109db
60hz 105.....60hz 111db
65hz 105.....65hz 111db
70hz 105.....70hz 112db
75hz 104.5...75hz 112db
80hz 104.2...80hz 110db
85hz 104.....85hz 112db
90hz 104.....90hz 113db
95hz 104.....95hz 112db
100hz 104.5.100hz 113db
105hz 105....105hz 112db
110hz 105....110hz 112db
115hz 105.5.115hz 113db
120hz 106.5.120hz 113db
 
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Brand of my DMM =?
Not sure off top of my head. I just measure at the amp using a sine wave. Used my Radshack SPL meter for a quick check. My 50 Hz is right at yours at 104. But I just realized amp might have 50 hz cut on. Will have to remember to check for that.

I measured the resistance of the driver.
Though it first states 8 ohm it immediately goes down to 5. I will measure a few of the others when I get a chance.

I did smile at the sensitivity.
Though it doesn't go as low as the Apache is is definitely louder. With it being smaller that is a BIG plus. Weight seems to be less than 40lbs. I will weigh it tomorrow and see
(digital shipping scale)
 
Jim; I have finished the convershoin of your sub to 3/4" and removed all the restriction points. I did not have time to learn Sketchup so I did it by hand with a 1 to 1 drawing. The box is bigger. Still 22" wide outside but now 26" deep and almost 32" high. It simed just a littel higher in SPL than your box, but I could not figure out how to save the hornresp screens. Here is the data to enter if you what to see.

S1=462.90cm2, S2=512.37cm2, S3=793.55cm2, S4=1818.8cm2, and S5=2215.58cm2
L12=17.15cm, L23=128.9cm, L34=80.65cm, and L45=21.90cm

The over all path leght is about 97.875" long, but do you do the box resonance from S1 to S5 or S2 to S4 in a tapped horn.

I will post some drawings next week and have 25 sheets of BB 18mm 13 ply coming from Ohio.

Saw Dust soon!!!!!!!!!

Andy
 
Jim; I have finished the convershoin of your sub to 3/4" and removed all the restriction points. I did not have time to learn Sketchup so I did it by hand with a 1 to 1 drawing. The box is bigger. Still 22" wide outside but now 26" deep and almost 32" high. It simed just a littel higher in SPL than your box, but I could not figure out how to save the hornresp screens. Here is the data to enter if you what to see.

S1=462.90cm2, S2=512.37cm2, S3=793.55cm2, S4=1818.8cm2, and S5=2215.58cm2
L12=17.15cm, L23=128.9cm, L34=80.65cm, and L45=21.90cm

The over all path leght is about 97.875" long, but do you do the box resonance from S1 to S5 or S2 to S4 in a tapped horn.

I will post some drawings next week and have 25 sheets of BB 18mm 13 ply coming from Ohio.

Saw Dust soon!!!!!!!!!

Andy

Hey, it seems like you actually bettered a box that is already a winner.
 
Oh yes Jbell! My fluke 45 measures TRUE RMS from 20Hz-20Khz and audio power calculations from 1.6 to 16.4 Ohm. But it only measures correct with a single sine wave signal. (It also measures dB’s from 2 to 8000 Ohm impedances and frequencies from 5Hz-1Mhz). :p

Djim:

you have a very fine piece of test equipment that has the ac+dc function. I included the link since there had been discussion about 'true rms' in the recent past. I though it may be enlightening for some on how true rms meters work.

maybe some day I'll step up to a 'real' meter... till then, I suffer through with my 'poor mans fluke'
 
DIY highpass for making things idiot proof? That's what xti amps are for....
Crown XTi-1000 Stereo Power Amp

Ben/Scott, I appreciate the thought, and I've even considered a 500uf passive or other type of active protection for my subs... but I just can't beat the simple setup of the xti.


$329 for full '3yr no fault' warranty b-stock... delay, dsp, eq, highpass, limiter, amp... all in a password protected, front panel lock out, 17lb all digital chassis.... Runs a pair of tops and a pair of subs beautifully. And limits out WAY before 900 watts per driver is possible. Using the internal 'Y' so that there is only a single audio input, and a single volume control even keeps peoples hands off of the sub/top volume ratio, so things always sound the way you want them to sound. To top it off -- 2 channel speakon cables even prevent mis-wiring on setup.... just chain all the speakers together.. Start on the side/top, go to the 2 center clustered subs, and then on over to the other side top.... beautiful.

I've been using nothing else for my school installs.... which have to be idiot proof....

This has me very curious/interested..
1. Are you running only 1 XTi amp for all 4 cabs/feeding each SS15 w/only 250W?
2. Does the XTi have a 'brick-wall' limiter?

I'm looking for my best option for installs and a lot of them are for clubs. I worry, even w/proper gain structure, that a novice DJ will get too happy w/the channel gain and get well into the red. I understand there may not be anything to prevent this other than giving proper instructions to each DJ.

How have you found the XTi amps to do with the lows? Find any drawbacks yet?

Regards,
Justin
 
This has me very curious/interested..
1. Are you running only 1 XTi amp for all 4 cabs/feeding each SS15 w/only 250W?
2. Does the XTi have a 'brick-wall' limiter?

yes,and yes...

The xti1000 with the brick wall limiter engaged is monkey proof. The ONLY way a dj could disable or in any way defeat your settings would be to have access to the rear of the amp, have a usb cable and laptop running the bandmanager software and know your password.

For installs I like to limit at 1/2 PE of the drivers so I have 100% reliability no matter what, which is why the xti1000 fits exactly what I need. If you want a bit more bass for a DJ set up that is still monkey proof, run 3 ss15 cabinets, a pair of tops and step up to an xti2000.

As far as running subs with one channel of an xti -- I have had zero problems.
 
I've been looking for a name for my weekend hire company.

"Monkey proof systems" would be perfect. :D

yea, that's it.... and it fits. not even a monkey could jack this up...

eq -- crossover -- limiter -- amp, in a single chassis. The entire gain structure is your mixer and the amp... that's it. The only thing that works on the front is the power switch and channel one volume knob. And the volume knob only goes to 10, not to 11.... Channel 2 knob doesn't even do anything when the 'internal y' input selection is made.

You can limit in 3db increments each individual channel, so your tops can have a different limit than the subs. I mean..... it's MONKEY PROOF !!
 
I assume nominal 8ohm and test either at 2.83v@1m or 28.3 volt@10m.
Jim what signal are you using to set the 2.83 volts? IE can I set the gain of the amp to get 2.83 volts RMS using 60Hz and regular DVM and then do the SPL cheaks. Or do I have to readjust the gain of the amp for each frequency I test? I thought some said thare was a thred or a link for the testing setup and procedures?
Thanks Andy
 
yes,and yes...

The xti1000 with the brick wall limiter engaged is monkey proof. The ONLY way a dj could disable or in any way defeat your settings would be to have access to the rear of the amp, have a usb cable and laptop running the bandmanager software and know your password.

For installs I like to limit at 1/2 PE of the drivers so I have 100% reliability no matter what, which is why the xti1000 fits exactly what I need. If you want a bit more bass for a DJ set up that is still monkey proof, run 3 ss15 cabinets, a pair of tops and step up to an xti2000.

As far as running subs with one channel of an xti -- I have had zero problems.

Well, this answer is only....EXACTLY what I was looking for :p

So, with the system setup this way, will the drivers/amp not get damaged from under-powering and hitting the limiter constantly (IF the performer treats the mixer's output to do so)?

Using the SS15 as an example, how does this setup compare (other than dollars & cents) to a setup where the amp has 500W/63V to 1000W/89V rms available per driver with the brick wall limiter set to a few dB below 63V?

Last, but not least: I remember you speaking of going from the amp output to a top, that top to the subs and the subs to the other top. This is with using 12GA ext cord for speaker wire with speakons, right? Would you mind further explaining how this all works?

Regards,
Justin