3 way active with real punch.. which way would you go.? Pro driver or .?

[Audionaut]

I was talking about times when men still wore hats on a daily basis. When "the 15" was the real thing, and all below a sad compromise

You've cleverly avoided the real question, but the fact is that no 8-inch speaker, no matter how good, can do the same job at the Low Frequencies as a 15-inch speaker of the same quality.

 

[crazycloud]

To do my wife a favor, I then built loudspeakers whose target description was somewhat different: As small as possible, as loud as possible, yet as clean and linear as possible.

The result was this little power dwarf, which doesn't show its capabilities above 80 Hz.
From 90 Hz, I coupled another Beyma 18 inch as active support.

Is that a B&C 8" coax? If so, which?

My German friends and acquaintances thought the speakers looked: “a bit big”, “completely oversized - where should you put them in normal living rooms?” “God, they're ugly!” “Interesting (that's what they say in Germany when you don't want to offend anyone)”

Big? My last surrounds (4x) were 15/10/1+WG and look about the same size as yours. In a 6x3.2x2.4m room.

 

[Audionaut]

Is that a B&C 8" coax? If so, which?

8FCX51 8Ω - Coaxials - B&C Speakers

www.bcspeakers.com

 

[Jaxjax]

What you're hoping to do is something I've been evolving for 30 years starting with passive components and 10+ with digital XO starting with a Minidsp 4x10 to do XO, time, EQ and SPL corrections to the diverse drivers involved in a 3-way XO + subs. FYI, Minidsp hardware Sharc processors are pretty limited with what you can do in bass frequencies and the basic Dirac they offer is also pretty crappy by comparison. I do it all via computer now which allows far greater flexibility.

I built these HUGE monkey coffins based on the "golden mean" dimensions in all the speaker building books back in the 80's following all the T/S guidance available at the time and they are dimensionally huge sealed enclosures (I'm committed, 180 liter, 6.4 cubic foot) to adequately cover the frequency range of 30-20kHz I was hoping for. In retrospect, in futility. The enclosures have remained huge but have undergone massive internal changes over the years as well as speaker drivers as I learned better practices, gained access to better software tools and trying to understand half of what some of the really smart people here know.

I know you're looking at 80-120Hz zone but if you want to activate the room and reinforce the presence in that frequency range get some subs. I'm in a 16x20x11', 3500 cubic foot space and XO my 15" woofers to two subs at 65Hz because it works better in MY space and speaker placement.

My goal has been to have an even sound throughout the room (it's my art studio, I move around) instead of a specific listening position so have added some absorption and diffusion for my specific needs.

Some things not mentioned often enough when going active. Sorry if obvious but I learned the hard way.

• Pay specific attention to the sensitivity of your W/M/T combination with the intent in advance that you're applying EQ and DSP which will automatically reduce your overall SPL.
• Also, very important, the input sensitivity and voltage gain for the amps you want to use for each driver speaker pair. No use really having a stellar SINAD for your tweeter amp if it only has 13dB of gain and now you have to pad down your 89dB sensitivity woofer to get to your 94 SPL/w/m tweeter audible.
• With larger midrange drivers (5" +) they start to beam at lower frequencies off axis. Be aware of this depending on the directivity you are hoping to achieve with your build.
• Impedance of driver selections in harmony with each other and the amplifiers that are driving them - voltage limited vs power limited.

Current configuration of drivers to fill in what's not in the sig:
GRS 15PT8 15" woofers
B&C 6md38 6.5" midrange
Audax two34xo 1.25" dome tweeters
15" Dayton rss390hf-4 sub + a SVS 12" SB1000 in opposite corners (not ideal but necessary)

currently using LR4 XO at 65, 350, 1500kHz but one of the subs uses a gentler slope on the HP because it integrates better somehow with MY room in SPL and phase.

Good luck! Have fun! I know you will, I have. It will, eventually, sound awesome!

It will definitely be fun as it's a no pressure affair. I'm definitely making the box with removable front baffle. I'm also going to make the tweeter recess @ 104.25mm to accept a very large number of different tweeters if wanted including the new Purifi. I am also heavily leaning towards a 6.5 Purifi mid if I can make it work.. That leaves the woofer & it's going to be either one of the 13" scan speaks or Pro. & hoping to use 15" Pro. We see what I can come up with. I already have the 3- Yamaha P2500S amps so might as well use em to start. I wish Sweetwater carried speaker building software.....

 

[Heinrich]

You've cleverly avoided the real question, but the fact is that no 8-inch speaker, no matter how good, can do the same job at the Low Frequencies as a 15-inch speaker of the same quality.

If so, not intentionally referring my answer to your question. My statement was not provable to begin with. I didn't tell the criteria. It was sloppy and eventually rhetorical.

Actually I wanted to convey that the 15" is a urban legend born in the 50s. Today you'll be better off to suplement a dedicated 8" bass with a dedicated 8" midrange. I can't imagine anyone to try it, though. Except for myself, of course. For instance, JBL's M2 is a fail, in my humble opinion.

That nearly brings me to rant about the lack of innovation. If people like to stick to what they know to be good for them, well, who am I to contradict. So I stop, before it even begins, my rant, which was meant as a reminder initially.

 

[Jaxjax]

8FCX51 8Ω - Coaxials - B&C Speakers

www.bcspeakers.com

View attachment 444583

View attachment 444584

How hard was it to get this driver to behave & XO .?, it's an interesting one w/ the Polyimide diaphragm.

 

[digitalfrost]

Not sure if it fits the bill. Chassis are slightly more than 1k per side:

1x KE 25 SC - 8 Ohm 171,15
2x AL 130 M - 8 Ohm 156,52
2x TIW 300 - 8 Ohm 304,27

1092.93€

Combine with 3-way active module of your choice.

Max level is above 110dB at all times, in bass ~114dB.

 

[Audionaut]

How hard was it to get this driver to behave & XO .?, it's an interesting one w/ the Polyimide diaphragm.

Not too difficult with active equalization.
It has very good omnidirectional behavior.

 

[DWPress]

It will definitely be fun as it's a no pressure affair. I'm definitely making the box with removable front baffle. I'm also going to make the tweeter recess @ 104.25mm to accept a very large number of different tweeters if wanted including the new Purifi. I am also heavily leaning towards a 6.5 Purifi mid if I can make it work.

Removable front baffle a good idea, mine is a double layer where the outer is heavily screwed in from the inside. I've redone my baffles 3 times over the years when driver arrangements and sizes fail to continue to be a good idea. I just recently replaced my mid with the B&C I listed earlier. I seriously considered the Purify drivers but they started off-axis beaming to early for my tweeter XO + that's a lot of money per driver. The B&C's weren't cheap either but more appropriate for my needs.

I've been remeasuring the system for days getting the new XO and gains set properly but here's the current working result from 10 feet back, more work to do on those decay times....

 

[Gibsonian]

I recently built some speakers using Faital Pro 12rs430. I really like them and can recommend them. High power handling, high Xmax, low Fs, efficiency not bad, I think 93db. Goes lower than most all 12 and 15" pro audio bass drivers. Bought them from European supplier to save bucks.

 

[Jaxjax]

I recently built some speakers using Faital Pro 12rs430. I really like them and can recommend them. High power handling, high Xmax, low Fs, efficiency not bad, I think 93db. Goes lower than most all 12 and 15" pro audio bass drivers. Bought them from European supplier to save bucks.

Nice driver..I just checked it out on US Speaker.

 

[Gibsonian]

In the pro audio driver world the Fs of this driver lower than most 18".

 

[Jaxjax]

In the pro audio driver world the Fs of this driver lower than most 18".

I bumped into Troels Gravesen build with the 12RS430. I think it might be advantageous for me to copy his build but w/ removable front & back & convert it to active dsp via Minidsp flex 8 balanced for easier hookup to my amps. His cabinet size I can deal with for measurements. Sure wish Troels was a full active fella.
His build uses
Faital 12RS430
Faital 6RS140
Scan Speak D3004-660000 or D3004-664000 Beryllium
His came out 90db total but i should gain a few db I suppose without the passive insertion loss, so maybe 92-93 db.?

 

[Heinrich]

I bumped into Troels Gravesen build with the 12RS430. I think it might be advantageous for me to copy his build but w/ removable front & back & convert it to active dsp via Minidsp flex 8 balanced for easier hookup to my amps. His cabinet size I can deal with for measurements. Sure wish Troels was a full active fella.
His build uses
Faital 12RS430
Faital 6RS140
Scan Speak D3004-660000 or D3004-664000 Beryllium
His came out 90db total but i should gain a few db I suppose without the passive insertion loss, so maybe 92-93 db.?

He only shows off-axis data in the lateral direction, no vertical, and only up to 30 degrees. I‘ve not found distortion, let alone intermodulation. The bracing scheme doesn‘t convince me, but it is quite elaborated with all the round-offs. The damping, well, there‘s no check if it is worthwhile for the money it takes. Finally it boils down to a lot of standardized rules followed, without scrutinizing them again, despite the cost and effort.

As you plan to drive the produce active, where‘s the point in replicating a passive design? You may chose asymmetrical position of mid/treble drivers, switch positioning top/down of mid and tweet, etc … squeeze 25 Hz out of it, because you just can, bigger volume as to dismiss the stands, equalizer substitutesThieleSmall alignment in full agreement with filter theory, etc … a waveguide for the tweeter might be in order too, etc … you‘re so much better off than a passive designer! Problem is, where to push the envelope, what is desirable other than sheer spl, and what isn‘t offered by the industry for cheaper yet?

 

[Roland68]

I bumped into Troels Gravesen build with the 12RS430. I think it might be advantageous for me to copy his build but w/ removable front & back & convert it to active dsp via Minidsp flex 8 balanced for easier hookup to my amps. His cabinet size I can deal with for measurements. Sure wish Troels was a full active fella.
His build uses
Faital 12RS430
Faital 6RS140
Scan Speak D3004-660000 or D3004-664000 Beryllium
His came out 90db total but i should gain a few db I suppose without the passive insertion loss, so maybe 92-93 db.?

Also check out the Visaton 890 MK III.
A very powerful speaker in all areas, also easy to activate.
Efficiency is approximately 94 dB; volumes above 120 dB are not a problem, but not recommended.

 

[Heinrich]

Also check out the Visaton 890 MK III.
A very powerful speaker in all areas, also easy to activate.
Efficiency is approximately 94 dB; volumes above 120 dB are not a problem, but not recommended.

Don‘t know if they sell this in large numbers still. The midrange horn is superseeded by constant directivity designs for literally decades now. Leaving the obvious problems with vertical radiation, and interferences from protruding edges alone, the group delay issues inherent to the design would spoil the exact target of the o/p‘s quest.

 

[Fledermaus]

Just in case, and FWIW - this is the way I'm currently attempting to achieve this purpose :

(More details following link above)

 

[dasdoing]

These aren't beauties

they are

 

[PB63]

Just in case, and FWIW - this is the way I'm currently attempting to achieve this purpose :

(More details following link above)

Audiohorn + PHL drivers?

 

[Fledermaus]

Audiohorn (X25 + BMS 1" driver), yes - below : B&C Speakers 8MBX51, SB Audience Nero 15SW800