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**dalbert02** · 01-05-2014, 07:53 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Originally posted by Brian Steele View Post

BTW - what are the internal dimensions of those boxes you've built?

They are internally 28" high X 17" wide X 9" deep = 4284 cu in - 120 cu in of bracing = 4164 cu in or 2.4L As you can see there is a 0.75" lip in the front that I thought would help protect the drivers but now (after reading so many posts) I think it may screw with the dispersion pattern.

I know I need to calculate and subtract the volume of the port(s), volume of the drivers and volume of the x-over, but even at 2.0L the above listed drivers (when modeled) do not seem to change their behavior all that much.

-dave

**Brian Steele** · 01-05-2014, 08:24 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Originally posted by dalbert02 View Post

They are internally 28" high X 17" wide X 9" deep = 4284 cu in - 120 cu in of bracing = 4164 cu in or 2.4L As you can see there is a 0.75" lip in the front that I thought would help protect the drivers but now (after reading so many posts) I think it may screw with the dispersion pattern.

I think you mean 2.4 cu.ft. instead of 2.4 liters

Any particular reason why you went with such a wide cabinet with shallow depth? With a 10" driver, I'd have probably opted for a cabinet that was narrower and deeper, to leave enough space for the vent's inside opening to be clear of the rear panel when the vent is mounted on the front baffle.

**dalbert02** · 01-05-2014, 08:44 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Ah, yes cu ft not Liters. Speaker dimensions chosen out of ignorance. I read long ago that speakers should follow the golden ratio, 0.6 depth 1 width 1.6 height. I can now see how this could be problematic. <sigh>

**zhillsguy** · 01-05-2014, 08:52 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Originally posted by Brian Steele View Post

Honestly, as you've already started to build the boxes, I suggest not worrying about it too much at this point. 80W power-handling in the pass-band really isn't that bad. Don't get caught up in "analysis paralysis"

. Every DIY speaker project is a learning experience to make your next DIY speaker project better

.

What's more important IMO at this point is if your new DIY speakers do not meet your requirements and/or don't perform well, you are able to quantify its deficiencies so if you have to modify and/or rebuild them, you'll have a pretty good idea of specifically where you have to focus your attention.

+1. It is a learning experience. It is up to you to decide if you have gone beyond the no-return point with this build.

Designing a full range speaker system with a crossover is not for the weak at heart, and I won't even attempt it. A simple sealed or ported subwoofer design/build is a little more forgiving, those are fairly easy. If you have read around on these forums then you know it is always recommended to build a ready made speaker design for the best results, and for good reason. When your first project comes out reasonably good and sounds great, nothing beats that feeling, and that provides high motivation for the next improvement. Everyone makes mistakes along the way....there are even threads dedicated to it.

I would still recommend going with one of the many designs available on these forums, following all recommendations from the designer.......they've done the heavy lifting for you, if you feel you can still turn back...... if not, there is always another build to do later.

**dalbert02** · 01-09-2014, 07:53 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

After much thought, I decided it would be best to build new cabinets. I will build a cabinet with the same dimensions as the JBL MP410 that uses the same driver 10" woofer and compression driver. However, will replace the 2412H compression driver with a Selenium D220Ti or a PVR D290Py whichever sounds best. I have read the D220Ti can replace a 2412H in several speaker but I also read the polyimide drivers sound better than titanium. My old boss used to say, "One carefully controlled experiment is worth a thousand expert opinions" so I am here to experiment. If the new cabs sound ok, will use the old cabs for a new build. I am thinking a B&C polyimide compression driver and QSC horn with an Eminence Kappalite 3015 as it models favorable in my 2.4 cu ft box. I would like to try active crossover and once I find a favorable crossover point, try my hand at building a passive crossover. I know everyone says it is difficult but I just gotta try! Worst case scenario, it sounds like garbage and I stick to active crossovers or sell the parts on eBay and lose a $100 or so. Thanks for all the advice, I'll keep you posted with the build. Attached is a pic of my first build, a subwoofer built with a Seas L26ROY driver. It gave me the inspiration to try to build/fix the PA speakers.
-dave

**67baja** · 01-12-2014, 02:45 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Sorry if I sound like a BFM fanboi, but I would build Jack 10s or 12s, or possibly one of Bill's new Simplexx designs. The Jacks are a very proven full range design and the Simplexx are his new easier-to-build line that should perform well. Ah, who am I kidding? I would (did) build Otop 12s and T30s.
Jack: http://billfitzmaurice.net/Jack.html
Simplexx: http://billfitzmaurice.net/Simplexx.html

**Sydney** · 01-13-2014, 09:27 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Originally posted by 67baja View Post

Sorry if I sound like a BFM fanboi, ...

No you're not - and yes you do :D

**dalbert02** · 01-21-2014, 06:51 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Update:
New cabs built mostly to the JBL MP410 spec but just a tad bigger as I used a 5 degree angle on my cuts. Some pics attached. Parts Express only shipped me one PRV compression driver (other is on back order) but first impression with just one speaker is rather impressive. I was listening to my first track, a track I know very well, and I heard a noise best described as static. I was ****** and thought it was something vibrating or ticking inside the cab. Come to discover it was the sound of the sampled vinyl in the music track, not the speaker, but sounded so real, I was looking for a loose connection.

Don't know why I never heard those particular ticks or pops before but I was impressed. Bass is a thousand times better than it was in the original plastic cabs, I could actually get by without a sub for rock music but it would be nice for hip-hop, rap, etc. Again, with just one speaker, I have been pleasantly surprised. I was listening to another track I know well and in a certain section is goes from rather quite to really loud. I know this. I expected this. But I was startled. It has a crispness / tightness to it that I have never experienced with any other speaker. The highs are now excellent. The lower mid-range to what I guess to be 40Hz bass is great. I am very pleased. If there is anything I could say negative about the sound at this point is the highs are a bit pronounced, but in a non-offensive way. Very articulate but an L-pad or resistor may be required for some.

Some notes on the construction: I painted the entire cab with clear polyurethane then painted the inside with rubberized automotive undercoating and the outside with truck bed liner. Both are Rust-o-leaum brand they had on sale at Harbor Freight for $5. I used Dayton handles on the top just like the 410's and there is only about 1/8" clearance between bottom of handle and the compression driver, that could have been a big mistake if there was not enough room. Home Depot sells 5 sq ft of 'small project' fiberglass for $6. I used a bag of glass in each cab.

I can't wait to get the other CD and do some real listening! Thanks for the advice to not build such a big cab, I can't imagine it could have been good!

-dave

**60CycleHumm** · 01-26-2014, 03:07 AM

Re: Need recommendation for outdoor block party speakers - build or buy?

These will do the trick -http://hornplans.free.fr/tl4050.html

**Brian Steele** · 01-26-2014, 08:53 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Nice work! To improve things, I think the next step you should be looking at is to find a way to measure what it is that you're hearing, so you'll have a better idea of not only where things may need to be improved, but how much they may need to be improved.

**dalbert02** · 01-27-2014, 07:50 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Originally posted by Brian Steele View Post

Nice work! To improve things, I think the next step you should be looking at is to find a way to measure what it is that you're hearing, so you'll have a better idea of not only where things may need to be improved, but how much they may need to be improved.

Thanks!
Any suggestions on test equipment? I downloaded a few apps for my iPhone, but they kinda suck in that they don't tell me much. I was hopeful to find a good RTA. The tone generator I found works well enough. I'd really like to get the Dayton audio analyzer but spending $300 to test speakers that cost me at most $200 is kinda silly. The really sad thing is I have access to a spectrum analyzer that goes all the way to 20Ghz but it can't go low enough for audio work. :(

-dave

**Brian Steele** · 01-27-2014, 07:58 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

Originally posted by dalbert02 View Post

Thanks!
Any suggestions on test equipment? I downloaded a few apps for my iPhone, but they kinda suck in that they don't tell me much. I was hopeful to find a good RTA. The tone generator I found works well enough. I'd really like to get the Dayton audio analyzer but spending $300 to test speakers that cost me at most $200 is kinda silly. The really sad thing is I have access to a spectrum analyzer that goes all the way to 20Ghz but it can't go low enough for audio work. :(

-dave

HolmImpulse an ECM 8000 mic and a decent mic/USB audio interface should do the trick. Shop around for other options. You're not looking for perfect 20-20KHz performance, but something with an in-band response that's flat enough for x-over duty.

**kblackmore** · 02-05-2014, 08:37 PM

Re: Need recommendation for outdoor block party speakers - build or buy?

The way I test is a ECM 8000 mic with a Behringer USB audio interface (cheap mixer I picked up in a pawn shop), Room EQ wizard software is free from www.hometheatershack.com/roomeq/ and very impressive with the results.

**Paul O** · 02-06-2014, 11:08 AM

Re: Need recommendation for outdoor block party speakers - build or buy?

I have to suggest PE's own EMM-6 measurement mic or if you want an all-in-1 solution the UMM-6 USB mic. I have the EMM-6 and use a small USB mixer and REW for a test system and it does a very good job.

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http://www.parts-express.com/dayton-audio-umm-6-usb-measurement-microphone--390-808

Dayton Audio UMM-6 USB Measurement MicrophoneThe Perfect Companion for Audio ProfessionalsThe Dayton Audio UMM-6 professional-quality USB measurement and recording microphone is designed to work with industry-standard third party recording and measurement software. The rugged construction and compact size make it the perfect companion for audio professionals who must work on-location performing acoustic analysis, monitoring audio levels, or recording. Each UMM-6 is calibrated individually using a laboratory-standard reference microphone, for consistent, repeatable PC measurements that match the level of precision offered previously only by expensive stand-alone microphones and measurement equipment. Works great with the Room EQ Wizard software. FeaturesPrecision condenser microphone for critical measurement and recording applicationsCompact, portable, accurate, affordableConnects to your PC or Mac via USB portRugged construction with high-quality componentsTrue omnidirectional pattern and calibrated flat frequency responseAccurate response from 5 to 20,000 Hz using the unique calibration filesFor professionals and hobbyists--design and tune speaker systems and arraysA carrying case with foam insert, 10 ft. USB connection cable, and a mini tripod mic stand are included with the UMM-6. MeasurementsCombining the UMM-6 and Room EQ Wizard provides you with an array of tools that are great for all audio engineers.Sound level meter with full integrating functionality including equivalent sound level and sound exposure level; mic/meter and soundcard calibration corrections applied; A, C or Z weightingReal Time Analyser with up to 1/48th octave resolutionFrequency response and distortion measurement using logarithmically swept sine signals for fast, accurate analysis of room acoustics and audio performanceTwo channel oscilloscope with a math channelHarmonic and intermodulation distortion measurement including harmonic phaseRT60 Decay plot using frequency domain analysis to provide decay data at much higher resolution and with narrower octave fractions than is possible with classical RT60 analysisImpulse Response delay calculation and adjustmentSpectral decay plots, waterfalls (Fourier and Burst Decay) and spectrograms (Fourier, Burst Decay and wavelet)Signal Generator with 11 different functionsClarity and definition parameters C50, C80 and D50 plus centre time TsImpedance measurement including Equivalent Peak Dissipation Resistance (EPDR) plot, component model for inductor and capacitor measurementsThiele-Small parameter calculation from sealed volume, added mass or dual added mass impedance measurementsAutomatic identification of peaks in the response, automatic assignment of EQ filters to peaks and optimisation of filter parameters to counter the peaks and track a desired target responseRoom Simulator supporting up to 8 subwoofersRoom resonance analysis to determine the frequencies and decay times of modal resonances with pole-zero plots of the response and any filters applied Frequency ResponseFrequency Response is a curve that shows how strongly an audio system reproduces different parts of the frequency range. A frequency response is related to its "impulse response" (the pressure signal that a speaker or sound system would make if it were fed by an extremely short pulse).Impulse ResponseThe purpose of a Impulse Response is to reveal how the frequency response of a loudspeaker is affected by the room at the location of the microphone. Harmonic DistortionHarmonic distortion is the unwanted addition of new tones to the original audio signal. These distortion products occur at multiples of the original frequency and are centered on the harmonics of the original. For example, a 1kHz fundamental that has been subjected to harmonic distortion will produce energy at 2kHz (2nd harmonic), 3kHz (3rd harmonic), 4kHz (4th harmonic), and so on.Cumulative Spectral DecayA waterfall (or CSD) illustrates, on a 3-D graph, how a speakers' energy decays or is radiated over a range of frequencies. Waterfall plots are used by driver and loudspeaker designers for driver selection, to identify resonances or reflections, and to view driver and waveguide behavior. Automatic EQThe EQ window allows you to customize and visualize the effects of filters based on the measurements taken with the UMM-6SPL Meter / Spectrum AnalyzerThe SPL (sound pressure level) meter allows you to measure how loud your source is while the spectrum analyzer shows you the relative SPL of frequency bands. OscilloscopeUse the Oscilloscope to view any sound waveforms. These might include music, your voice, or waveforms played by loudspeakers.RT60 AnalysisUse the Bass Decay analyzer to measure how bass notes decay in a room. This is a great measurement to understand how the room affects the low end. Calibrate Your UMM-6A unique serialized calibration .txt file will be available for your UMM-6. Once you receive your microphone, Visit the Dayton Audio calibration download tool where you will be prompted to enter the serial number found on the base of your calibrated UMM-6. After entering the serial number, your unique calibration .txt file will be available for you to download.cALibration Download tool Join Our Speaker Building Community Learn more about OmniMic from seasoned professionals

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http://www.parts-express.com/dayton-audio-emm-6-electret-measurement-microphone--390-801

Dayton Audio EMM-6 Electret Measurement MicrophoneThe Dayton Audio EMM-6 is a precision electret condenser microphone designed for measurement and critical recording applications. The extremely flat frequency response and true omni-directional polar pattern make it perfect for use with room acoustic analyzers and audio measurement systems. The EMM-6 microphone is individually hand calibrated using a laboratory standard Brüel & Kjær microphone in conjunction with a DAAS computer measuring system. Each microphone includes stand mount, foam windscreen, transport case, and its own unique printed and downloadable calibration response graph and .txt data file (see below).FREE! Download your unique calibration .txt file.A unique serialized calibration .txt file is available for the EMM-6. Once you receive your microphone, Visit the Dayton Audio calibration download tool where you will be prompted to enter the serial number found on the base of your EMM-6. After entering the serial number, your unique calibration .txt file will be available for you to download.Specifications: • Capsule type: 6 mm electret condenser • Polar pattern: omni-directional • Frequency response: 18 Hz - 20 kHz • Impedance: 200 ohms between pins 2 and 3 • Sensitivity at 1 kHz into 1K ohm: 10mV/Pa (-40 dBV, re. 0 dB = 1V/Pa) • Max SPL for 1% THD @ 1 kHz: 127 dB • S/N ratio: 70 dB A-weighted • Connector: gold plated XLR • Phantom power: +15V to +48V, 4 mA • Weight: 144 grams.

**dalbert02** · 02-09-2014, 10:24 AM

Re: Need recommendation for outdoor block party speakers - build or buy?

Thank you for the excellent suggestions. I will purchase a mic and see what I have!
-dave

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Need recommendation for outdoor block party speakers - build or buy?

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