Suggestions to "improve" Flamencos

[kwingylee]

Guys:
Recently, I was able to pick up a set of 416-8C woofers on the cheap to put into a set of woofer-less Flamenco cabinets (I took the original 416-8As from the Flamencos and put them into my 825s to make A7s). I also replaced the stock Flamenco's 807 symbotik drivers (I know these are weird Flamencos) with 902-8Bs that were sitting around. With the stock 809 crossovers and the midrange level turned down, the speakers sounded really good. As these are technically no longer Flamencos and closer to all ferrite model 19s, I am looking for ideas to improve them further. Some of my thoughts include using model 19 crossovers, as well as modifying the cabinets to increase the internal volume so its gets closer to the model 19's 9.5 ft**3. Level. I believe the current Flamencos internal volume is somewhere around 6.8 ft**3? I am thinking of replacing the back panel and building a stand beneath them ti gain the extra space. What do you guys think? Are my estimates of the internal volumes correct? Or should I just leave them alone and enjoy them as they are. I missed my model 19s (never should have sold them) and maybe this is my way of getting them back.

[kwingylee]

Additional searching online led me to a post by GM in the DIYaudio/Multi-way speakers forum from 2014:

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Don't know of any article, but Altec recommended <6 ft^3 for ducted port and >6 ft^3 for bass reflex. 7.5 ft^3 was optimum sealed.

The M19 is a ~ 8.35 ft^3 net BR, so not too large since a T/S max flat is around 12.3 ft^3 and the pioneer's so called 'ideal' alignment makes it ~18.38 ft^3 for a Fs tuning using the original T/S specs.

Note that the 416-8C was audibly under-damped in the M19 though, so this may be where the confusion lies.

I did two different downsized M19s for some folks; one that condensed it into a simple rectangular cab of the same net Vb rather than the three cab + base assembly and the other is downsized closer to a M14 with a slot duct vent, but if they got built I don?t remember them posting/PMing anything.

Regardless, it obviously can be shrunk quite a bit using ~aperiodic loading with the trade-off of course being a higher F3, etc..

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Which indicates a different path: instead of making the Flamenco cabinets into the equivalent model 19 cabinets (in terms of effective internal volume), may be the Flamenco cabinets fall into GM's second suggestion: A down size M19 cabinet closer to a M14. At this point, I have no idea what the internal volume of the model 14 is, but the Flamencos seem to fit the 6 cubit ft ideal recommended by Altec. May be I am already there...:-)

GM

[GM]

Hmm, 2014 was a very bad year for me and apparently I couldn't find my notes and memory failed me also on one minor spec; I'd done a very accurate calculation of an actual M19, so for the record it's net volume [Vb] was ~8.622152778 ft^3.

No M14 dims, they're on a damaged HD and maybe on another HD, but not really up to searching for it anytime soon, though was published here way back when IIRC, but can't remember when or what search description might work.

Anyway, the 846A = ~5.3776 ft^3 net, 846B = right at 5.5 ft^3 net.

GM

- - - Updated - - -

Which indicates a different path: instead of making the Flamenco cabinets into the equivalent model 19 cabinets (in terms of effective internal volume), may be the Flamenco cabinets fall into GM's second suggestion: A down size M19 cabinet closer to a M14. At this point, I have no idea what the internal volume of the model 14 is, but the Flamencos seem to fit the 6 cubit ft ideal recommended by Altec. May be I am already there...:-)

GM

Note the downsizing was for folks with space problems with the downside of less bass, which in smaller rooms with more room gain was an acceptable trade-off.

A stretched [48"] 846B: Altec 416-Z 48" 846B MLTL - diyAudio

If space, speaker size poses no problems, then to date no one TTBOMK are regretting building large MLTLs that are at least what the pioneers decreed was the optimum balance between box cushioning [control] Vs power handing or [Vas] 22.74 ft^3/1.44 = ~15.8 ft^3 net tuned to actual Fs and of course ideally need to use the driver's measured Vas to get max box efficiency. If driven with a high output impedance amp, then ideally may need to be as large as Vas and then some in rare cases.

In looking up links, I see you're already aware of this and some of the builds, so looking forward to seeing which way you go.

GM

[kwingylee]

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Note the downsizing was for folks with space problems with the downside of less bass, which in smaller rooms with more room gain was an acceptable trade-off.

A stretched [48"] 846B: Altec 416-Z 48" 846B MLTL - diyAudio

If space, speaker size poses no problems, then to date no one TTBOMK are regretting building large MLTLs that are at least what the pioneers decreed was the optimum balance between box cushioning [control] Vs power handing or [Vas] 22.74 ft^3/1.44 = ~15.8 ft^3 net tuned to actual Fs and of course ideally need to use the driver's measured Vas to get max box efficiency. If driven with a high output impedance amp, then ideally may need to be as large as Vas and then some in rare cases.

In looking up links, I see you're already aware of this and some of the builds, so looking forward to seeing which way you go.

GM

GM
Thanks for the response. I was hoping to make slight mods to the Flamenco cabinet, such as extending the base to gain a tad more volume and still make it look good. I am ok with the sound as is and might try the aperiodic approach this summer by adding more fill and closing the space around the horn.

For the MLTL approach as per the advice you provided to me earlier, but 15.8 ft^3 is very big. My fine woodworking skills are not good so I will have to hire someone to build the cabinets. Its just not in the cards right now. I dont want to get rid of my A7 (416-8A, 808-8A) yet. By the way, I am using with the so call HIRAGA A5 crossovers I built per one of my threads to good effect).

[GM]

You're welcome!

Yeah, in the last few years I've diminished to the point where there's no way I could safely build my ~20 ft^3 cabs that i barely broke into a sweat when I did them at 24 [actually were 30 Ft^3 originally, but changed drivers and app after a couple of years from mains to just 'sub' duty].

If you can handle adding a column tall enough to raise the horn's centerline up to seated/whatever ear height would add some worthwhile increase in bass, maybe even enough to tune all the way to Fs if there's some decent room/boundary gain. Ideally the vent would be located down at/below its new internal height [i.d.]*0.848 or even down-firing if you want to sacrifice a bit of net Vb for feet/whatever, otherwise you'll get the same mid-bass notch that Bill's Stonehenge V? has.

Cool! Have read mixed reviews and my only hands on experience with multi-cells were with the huge 'A' series horns. WRT XOs in general, my preference short of modern digital is strictly old school, as in pre ~1950, which nowadays is way too rich for my blood since most components have to be custom made.

GM