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Old 20th March 2017, 10:27 PM   #1
Dr1v3n is offline Dr1v3n  United States
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Default Modified BK-12m BLH

Hello all, I would like to think I'm an audiophile. I still have reasonable hearing left although I'm 20yrs auto technician here in the US. I can hear up to 17kHz still, just tested yesterday with old school PAS audio software frequency generator (made for Win95) thru Creative headphones. So this reveals my age thereabouts...
I have built custom speakers in the past using Dynaudio tweeters and Morel 3" VC woofers with simple 3db or 6db butterworth crossovers? in a very small box...

Now onto the reason for posting!
I've assembled the BK-12m kit from madisound with the Fostek FE126En drivers. They sounded harsh to me. Hardly any bass and the mids were terrible, not to mention the more Amp I used the worse they sounded... Ok, let them break in you say? Ok, maybe I just didn't give them a chance then. Fair, but...

I've replaced the FE126En's with Vifa NE123W-08, and they sounded much better IMO from the getGO. No padding, no other mod's to the boxes other than screwing them together in order to take them apart and modify when necessary. More on that later!

Some other potential drivers I'm looking at for this enclosure are 2 of the Markaudio 4" drivers: The Pluvia 7 Gold or the Alpair 7.3

As an owner of pair of Inifinity RS-5's, I used to favor D'Appolito config. They still sound good, but I was amazed the Vifa's had more bass, from a single 4" driver in Scott's BLH enclosure and had the advantage of point source, which I remember this from the old days being the holy grail to speaker building.

So this is why I'm pursuing this modified design until it's end.

Currently I own 2 BK-12m's with the Vifas. 2 more boxes are on the way and I have 2 more Vifas ready to install. I intend to experiment: either stack 2 boxes driver to driver, or place them wide, i.e. 2 speakers on the left same plane separated. Identical for right channel.
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Old 20th March 2017, 11:31 PM   #2
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Quote:
Originally Posted by Dr1v3n View Post
I've assembled the BK-12m kit from madisound with the Fostex FE126En drivers. They sounded harsh to me. Hardly any bass and the mids were terrible, not to mention the more Amp I used the worse they sounded... Ok, let them break in you say? Ok, maybe I just didn't give them a chance then. Fair, but...
The 126's have a peak at ~6-8kHz, which makes them sound "shouty". You could try a notch filter to tame this peak.

Quote:
Originally Posted by Dr1v3n View Post
Some other potential drivers I'm looking at for this enclosure are 2 of the Markaudio 4" drivers: The Pluvia 7 Gold or the Alpair 7.3
FH3 (http://www.frugal-horn.com/FH3.html) would be a much better enclosure for either of these two drivers. Lots of builders enjoying their A7.3's in these horns.

jeff

Last edited by vinylkid58; 20th March 2017 at 11:38 PM.
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Old 21st March 2017, 02:29 AM   #3
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Quote:
Originally Posted by Dr1v3n View Post
!

As an owner of pair of Inifinity RS-5's, I used to favor D'Appolito config. They still sound good, but I was amazed the Vifa's had more bass, from a single 4" driver in Scott's BLH enclosure and had the advantage of point source, which I remember this from the old days being the holy grail to speaker building.
.
Things have changed. Line arrays, synergy horn, even open baffle have become interesting alternatives because of evolving technologies in driver designs.

Don't get stuck thinking there's only one way. Look around, peruse and don't be afraid to try something new. You might be pleasantly surprised.
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Old 21st March 2017, 05:50 AM   #4
chrisb is offline chrisb  Canada
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Sam - have fun with all your adventures, and FWIW - my association with the FH family aside - the A7.3 has long been my personal second favorite fullrange driver - the MAOP7 version thereof taking first place.

Not all will agree, and that's part of what makes this hobby so bloody much fun - just don't feel you need to constantly justify your preferences, or changes in mind along the journey to all - I certainly as fork don't

cheers, and laki maika'i

Yes, I'm sure you'll all be relieved when my current vacation is over I'm back to west coast Canuck vernacular
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Last edited by chrisb; 21st March 2017 at 05:59 AM.
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Old 21st March 2017, 10:25 PM   #5
Dr1v3n is offline Dr1v3n  United States
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Thanks guys and cheers Chris. Vaca in Hawaii eh? Have fun!
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Old 21st March 2017, 10:36 PM   #6
Dr1v3n is offline Dr1v3n  United States
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Yesterday, I got my Dayton iMM-6 calibrated mic for my droid phone using an app called Advanced Sprectrum Analyzer and did some quick measurements of both speakers using pink noise, on an Audiosource Amp 3 class A/B amp, without calibrating the mic. The first 2 pics are with the mic about 3ft away. The second are about 10 ft away aimed at the NE123-08. Definately shows a rolloff as it approaches 20kHz. Tonight I'll download the calibration info and retest tomorrow to see if there's any change. The yellow graph is when I used the peak hold function.
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Old 22nd March 2017, 06:03 PM   #7
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can we trust these measurements?
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Old 22nd March 2017, 06:20 PM   #8
Dr1v3n is offline Dr1v3n  United States
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At this point, consider them "relative" measurements... The Advanced Spectrum Analyzer App appears to work pretty good, but even in a "quiet room" has the same type of curve as above.

I'm looking into another Android App, called AudioTool. The previous app although free does not appear to accept external mic calibration data.
I'm having trouble making the Audiotool App accept my Dayton iMM-6 calibration data. This app however, does seem much more flatter with the external iMM-6 mic. I did pay the $8US for this app because it was advertised to work with this mic, along with the cal data...

Last edited by Dr1v3n; 22nd March 2017 at 06:23 PM.
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Old 22nd March 2017, 06:32 PM   #9
Dr1v3n is offline Dr1v3n  United States
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Also, for experimentation I got some Dayton mini-8 AMT tweeters, received today! Also, some Dayton 1% polypropylene crossover caps. 1.0uF, 1.5uF, and 2uF. Plan to put in parallel with the Vifa drivers and try placement in order to see if those cymbals sound better.
At least no inductors or resistors. Plan to put the tweeter Out Of Phase.
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Old 24th March 2017, 12:46 AM   #10
Dr1v3n is offline Dr1v3n  United States
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Quote:
Originally Posted by perempe20 View Post
can we trust these measurements?
Oh I think I see from your perspective now. That App has no resolution below about 80Hz... I never paid attention to any frequencies below 100Hz, obviously a critical measurement for these speakers. I'll take some new measurements with the new App called AudioTool. Still haven't figured out how to cal mic.
Also, instead of doing a distance test with the mic, I'll get close enough to where the Analyzer tool reads the Vifa driver SPL average, which is about 87dB abd report the distance.

EDIT: no tweeters in this test.

Last edited by Dr1v3n; 24th March 2017 at 12:50 AM.
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