What happens when Flint makes a Line Array?

[Flint]

Okay!!! Time for some measurements...

From the listening position placing the microphone so it is aimed at the left speaker from where my left ear is located while seated and listening for the left channel speaker, then placed where my right ear is for the right speaker, here are the two frequency response curves in the room:



Since these are line arrays and as such there is a ton of phase interaction between the drivers, I took 16 measurements, 8 for each speaker, at 8 locations across the overall listening area which consists of three smallish dining table chairs, then average all 16 curves together, this is what you get for an overall room curve:



In general, the overall response is +/- 3.5dB, 24 - 20,000Hz. Also, if you ignore the dip at 180Hz, you could say they are +/- 3dB, 25 - 17,000Hz. Either of those "specifications" is pretty darn good given what I paid for the components.

All in (drivers, wood, subwoofer amps, stuffing, pain/finishing, hardware, wire, crossover parts, etc.) these cost me about $970 for the ingredients. The value of the time I put into them is a different calculation.

 

[TitaniumTroy]

I call these the Flint Reference Standard, ala Infinity IRS. I think you call them Veronica or something like that?

 

[Flint]

I definitely do NOT consider them any "standard" I would put my name on. They are amazing, but not in the direction of reference accuracy and ideal reproduction.

 

[TitaniumTroy]

Not even El Cheapo SubPar Standard

 

[Flint]

Not even El Cheapo SubPar Standard

Ha! A shocking value.

 

[TitaniumTroy]

I want to see Flint build a Horn based system, followed up by an Electrostatic speaker one day. That would be really cool, just like this Limited Fund LineSource/sealed bass system is.

 

[Randy]

I want to see Flint build a Horn based system, followed up by an Electrostatic speaker one day. That would be really cool, just like this Limited Fund LineSource/sealed bass system is.

Well based on how that stuff works and how products are named we may have come up with something vernacular.

Flints new Limited Fund Line Source Sealed Bass (LFLS SB or sometimes referred to as Lifeless Sumbitches) speakers will be available for pre order soon. Make sure you are on the list to get yours.

I think the abbreviation works but we have to come up with a different trade name in order for them to sell.

And, @Flint don't fire me as your marketing director yet, it was my first try.

 

[Flint]

Ha!!! I sold my Monster Power unit to a guy who saw my on Craigslist and when he came to pick it up and pay he saw the line arrays and begged to let him listen to them. Of course I obliged and he was impressed. I think he was more impressed by their sheer size and the fact a 35 year old 5 watt Realistic (Radio Shack) amp was driving them. Like most audio nuts, he clearly believed that so many speakers would require a huge amp, bigger than normal, in order to play loud. We ended up talking for about 30 minutes, but he was struggling with the idea of a tiny POS amp making that much sound.

 

[Flint]

I've probably made my point with the 5 watt amp. It does reach its limits at the levels where I like to demo the line array system. So, I may put my old Berhinger A500 on them, which is capable of about 18dB more output before clipping. It is probably better in the top treble, anyway. But I've been impressed by the little Realistic amp.

Holy Smokes!!! When I looked up the photo I found the original specifications for the amp. It is actually a 2 watt amp!!! Moving to the Behringer A500 would get my a whole 20dB of increased output!!!

Realistic SA-150 Specifications:

Power output: 1.8 watts per channel into 8Ω (stereo)
Frequency response: 20Hz to 25kHz
Total harmonic distortion: 1%
Input sensitivity: 2.5mV (MM), 200mV (ceramic), 160mV (line)
Output: 150mV (line)
Speaker load impedance: 8Ω to 16Ω
Semiconductors: 4 x transistors, 2 x diodes, 1 x LED, 1 x IC
Dimensions: 89 x 236 x 175mm
Year: 1984​

 

[Flint]

I posted this in the Rocketman thread and wanted to include in this thread dedicated to the Line Array speakers.

I measured the THD with the subwoofer turned off. I based the levels on them being about 88dB SPL at the listening position, though the mic was closer (thus the higher SPL in the title).


Make note that comb-filter distortions cases by multiple drivers reproducing the exact same signal at the exact same voltage inputs will increase the harmonic distortion. So, at higher frequencies the harmonics increase as the wavelengths of the frequencies get shorter than the difference in distance between the speakers and the listener (or microphone).

What was impressive to me was that sixteen 4.25" mid-woofers were generating a tiny .01% THD in the range from 80Hz to 500Hz while producing 88dB SPL 14 feet away. I think that is incredible and worthy of a prize for the little speaker that could - at least when working in numbers.