Crown Power Base 2, Output Voltage Test

Is this amp OK?
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scornil01
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Crown Power Base 2, Output Voltage Test

#1 Post by scornil01 »

** I didn't want to flood the forum by starting a new thread regarding this amp as there is a lot of information regarding this amp already within this thread. the voltage test is a few posts down.**

Hello all,

I have an old Crown Power Base 2 amp will be creating a new PA system for DJ use. I will be mostly using this system for small weddings and small events.

Pair of rectangular TLAH. Each with 8 or 9 Goldwood GW-4028/S and 12 Goldwood GT-302/S. Maybe you guys can help with deciding between 8 or 9 woofers

Pair of Tuba18's with Tangband w8-740

Will my Amp suffice?

The Crown Powerbase 2 specs that I can find:

All specifications apply to units in Stereo mode with 8-ohm loads
and an input sensitivity of 26 dB unless otherwise specified.

Standard 1 kHz Power: refers to maximum average power in
watts at 1 kHz with 0.1% THD+noise.

Full Bandwidth Power: refers to maximum average power in
watts from 20 Hz to 20 kHz with 0.1% THD+noise.

120 VAC, 60 Hz Units: refers to amplifiers with dedicated transformers
for 120 VAC, 60 Hz power mains.

Performance:
Frequency Response: ±0.1 dB from 20 Hz to 20 kHz
at 1 watt.

Phase Response: ±10 degrees from 10 Hz to 20 kHz
at 1 watt.

Signal-to-Noise: A-weighted, better than 105 dB below
full bandwidth power. Better than 100 dB below full
bandwidth power from 20 Hz to 20 kHz.

Total Harmonic Distortion (THD): Less than 0.05%
at full bandwidth power from 20 Hz to 1 kHz increasing
linearly to 0.1% at 20 kHz.

Intermodulation Distortion (IMD): (60 Hz and 7 kHz
4:1) Less than 0.05% from less than 158 milliwatts to full
bandwidth power.

Damping Factor: Greater than 1,000 from 10 Hz to 400 Hz.

Cross Talk:
Greater than 90 dB below full bandwidth
power from 50 Hz to 2 kHz, rising linearly to
greater than 66 dB at 20 kHz.

Common Mode Regection: Better than 70 dB
below rated full bandwidth power from 20 Hz to 1 kHz
falling linearly to better than 50 dB at 20 kHz.

Controlled Slew Rate: Greater than 13 volts/ms.

Voltage Gain: 20:1 ±3% or 26 dB ±0.25 dB at the maximum
level setting (Input Sensitivity switch set to its 26
dB position).
Power Base-2 : 64:1 ±12% or 36.2 dB ±1 dB at 0.775
volt sensitivity; 35:1 ±12% or 31.0 dB ±1 dB at 1.4 volt
sensitivity.

Output Power: The following specifications are guaranteed
minimums for standard 1 kHz power. For more information,
see the power matrices in Figures 4.1 through 4.6
(maximum average power @ 0.1% THD + N).
Attachments
Table found in the owners manual
Table found in the owners manual
Last edited by scornil01 on Mon Mar 02, 2015 11:55 pm, edited 2 times in total.

Grant Bunter
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Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#2 Post by Grant Bunter »

Hi there,

Intrigued with your thoughts regarding cab selection.

The sales page suggests TLAH is perhaps better suited to installs than portable use. I think a lot of people would probably suggest the SLA pro.
Similarly, the T18 is designed for home use, where it will benefit from room gain, say in small home theatre.
With no setting of high pass etc (ie not for "pro" use) I would be leery of using that cab in a semi pro situation, driving it to hard, and blowing the driver(s).
Equipment failure (for whatever reason) will hurt your business.

So you perhaps need to be looking at at least the T24 with, say, BP102 drivers given your amp output.

I understand your choices may have been made on what you plan to carry the system in vehicle wise, but better to choose the correct cabs for the job at hand...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Tom Smit
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Location: Sarnia, Ont. Canada

Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#3 Post by Tom Smit »

The most power that you would want to put in a 9-driver TLAH would be 120w. Same for the T18/TBdriver. Having said that, you would need a hard-knee limiter in front of your amp.

Is this to be a multi-purpose build, ie, for HT and small PA?

+1 to Grant's advice.
TomS

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Bill Fitzmaurice
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Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#4 Post by Bill Fitzmaurice »

Tom Smit wrote:+1 to Grant's advice.
+2. If you're doing pro sound you need pro sound cabs. Even the smallest venue is at least four times the size of the largest living room.

scornil01
Posts: 77
Joined: Sun Mar 25, 2007 5:08 pm

Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#5 Post by scornil01 »

Thank you very much for the reply guys

My choices on the tlah and the tuba 18 were basically due to convenience and to not having a truck anymore. Currently driving a 2013 accord.

I've long sold my dr200's which were my favorite but I don't think I have the patience or time to build those myself again.

I've also sold my omni12's which were great too and I may just build a pair again since the tlah's aren't recommended. I think I may be able to stack a pair of omni12's in my backseat.

As for the tubas, I've made a pair of tuba 30's, 20-24 wide if i rememeber correctly, that were just way over kill for the gigs that I actually needed to bring a PA system. Even bringing along 1 was a hassle. I remember bringing my autotuba to smaller gigs that sounded nice to me. And I do have an unused w8 740 I purchased a long time ago to load into my autotuba but the McM sounded just fine. Which Is why I had the tuba 18's in mind

Since now I'm in a smaller apt I was thinking of making the tlah and use them for HT use and bring them along for wedding gigs. Dont really have the room for big cabs to stock. The majority of my gigs are at a bar or club where there is a house PA system and I just bring my laptop.

I have a 5 weddings so far this summer starting the end of may which Is why I'm planning to make some cabs instead of borrowing/renting some powered mackies from friends.

Do you guys think this crown amp can handle a pair of omni12's (deltalite 2512) and a single T24?

I do still have a pair of the kappa lite 3012LF's that I kept before selling my tuba30's. Can I apply those to the t24 with this amp?

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#6 Post by Grant Bunter »

Arrr things have become clearer lol

At least you already know you need to brick wall limit.

If it was me, I would build the TLAH's and leave them on the wall at home.
If a T30 and Otops 12's were way overkill, I can now see where you're coming from.
The 3012lf only fits from a T30 or T39 and up. Sell what you have to fund your latest build.
The latest plans for the T24 include the now newish 3010lf, with a voltage limit of 55V IIRC, way above your amps output capability.

What you could do, and would be within your amps capability, would be to build a single T24 with BP 102 (limit 35V) and 2 half size SLA pros. That would require the small SLA's to run in mono. The 2 half size SLA's could then double as surrounds at home, and the sub could also be used at home. That system should be adequate for your DJing needs, and really, can't get any smaller.

In output terms, a pair of Otops are going to way overun any single of the smaller subs, be it autotuba (which I wouldn't use anyway in DJing), T18, or T24.

Hoping this helps...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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whines
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Location: Austin, Texas

Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#7 Post by whines »

I personally think that slim t39's are easier to fit in a car than a t24. A t39 slim would go across a back seat with tops on top of it.
2xJ15, THT, 4xT39 3012 (2x15", 2x20"), 2xSLA Pro, 2x short SLA Pro (Dayton), W6

scornil01
Posts: 77
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Re: Crown Power Base 2, Output Voltage Test

#8 Post by scornil01 »

Hello All

i apologize for not thanking you all for the input in this thread. i completely forgot to update.

As of now Ive Just finished Building a pair Of SLA pros with the Dayton Speakers which i love!! Ive posted some pictures in the build thread. Im still deciding on a pair of Tuba24's or a single SlimT39's but i am leaning towards the t39. Regardless im going to have to update to a new amp

Ive just finished reading Lelands Sticky on testing the voltage Output and wanted to test This Crown Powerbase 2 amp.

Wondering if you guys can Check my work.

I acquired a 1khz signal from youtube:

http://youtu.be/oscE8Z5Zjjw

Hooked up My computer to my Behringer DDM400 mixer using a 3.5mm/rca adapter. used a xlr cableand hooked it up to a channel on the Powerbase Amp

Image

Set my mixer to reach 0db

Image

hooked up my multimeter and got a max result of 25-27v ac when i slowly turned up the gain knob on the amp.

Image

I Also have a Built in crossover in my Behringer Mixer. i dont know how good it is but i set it up like this:

Image

For some reason i had to adjust the balance more to the right for this test, it may have been the video i was using..

Image


Used this youtube video for a 200hz signal:

http://youtu.be/6E5XI3NL6QA

Hooked up an XLR from the SUBWOOFER output to a chanel on the AMP and i got an max output of around 4-5.5v

Image


i forgot to take pictures when i bridged mono, for the 1khz tone I think got around 60v
heres a pic of the bridged mono in the 200hz test:

Image


Did i do an accurate test? was it ok to use these videos from youtube?

Bruce Weldy
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Re: Crown Power Base 2, Output Voltage Test

#9 Post by Bruce Weldy »

Start over. Forget youtube for tones. Load audacity on your computer and create the tones there.

Turn everything off on your board relating to crossovers, limiters, feedback destroyer, or anything else. You want the pure signal with no processing. Use a mono out if there is one.

Crown has always been good about their numbers. Why are you testing the output? You can take the stated wattage and plug it into a calculator to give you the voltage.

According to the manual, this amp puts out 325 watts at 8 ohms. That's 51 volts.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

scornil01
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Re: Crown Power Base 2, Output Voltage Test

#10 Post by scornil01 »

Got it! Thanks I'll try again tomorrow

No reason really on why. I never hooked up a voltmeter to an amp before. After reading Leland's post on amp ratings I was just really curious. I guess now i want to see what I have to do to get it to show 51 volts for an output if it's possible.

I'm Trying to get at least half as knowledgable as all the people here! :fingers:

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Chris_Allen
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Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#11 Post by Chris_Allen »

Bill Fitzmaurice wrote:
Tom Smit wrote:+1 to Grant's advice.
+2. If you're doing pro sound you need pro sound cabs. Even the smallest venue is at least four times the size of the largest living room.
Unless you are in the UK where in some venues the playing area is actually smaller than your front room!
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

ripNdeb
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Re: Crown Power Base 2 for Pair TLAH and Pair of Tuba18

#12 Post by ripNdeb »

scornil01 wrote: I do still have a pair of the kappa lite 3012LF's that I kept before selling my tuba30's.
I could really use these if you don't end up using them. :)
2X OTop 112, 3012HO, melded - 2X T39, 27", Lab 12 - XF 212 - 4 DR250, 2 melded, 2 straight
2 20" T39 3012LF - WH10 - WH8 - in the shop - 2 more 20" T39s
http://saltandlighteureka.org still need a trailer :)

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escapemcp
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Re: Crown Power Base 2, Output Voltage Test

#13 Post by escapemcp »

2 things in your 200Hz test:

1) You have the xover set at 200Hz, so that means that it will be down by either 3dB or 6dB at the xover point. The 2 possible values (3 or 6dB) is because it depends on the type of crossover on the DDM (Butterworth/Bessel/etc or LR). I own a DDM4k also and have never found out what sort of crossover is in the units (I think I did find out that it is 12dB/oct though).

2) You only have the output set to -2dB on the 2nd test also. It is PEAKING at ~0dB, but your RMS output is -2dB
Image

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