big subs (18" +) for music only... driver recommendations

Looking to spend under $500 per driver. Haven't decided on cabinet yet. I have 2 full martys with dayton um18s that i love for my HT but I read that the pro audio drivers are better for music for their greater mid bass out put. The space is 32 x 34 x 8 feet. Looking to build 2 subs. As for why big subs I just like bigger subs but wouldn't be against 4 x 15 inch spread throughout my space.
I am in canada though so getting flatpacks is tough and I may have to get a speaker builder to make the cabinets for me.
Some of which you already know and have played with:

BMS 18n862
B&C 18TBW100
LaVoce SAN184.03

All are excellent. If you can do (4) 15 inch individual subs spread out, you can do the same with 18 inch sizes. Just do that instead. Tame the room modes, use EQ as needed, and be happy. Especially if you go sealed, you needn’t worry about max SPL capabilities for music performance. I would use Harman or Geddes’ recommendations, whichever fits your domicile. Minidsp has decent recommendations on multisub implementation.

Mid bass is indeed important, in fact more important for music. Use the UM18’s for your low bass and tie that in to midbass modules using the above drivers. You’ll enjoy it.

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I’m sure it’s quite good. But one of the reasons I recommended the BMS model and the B&C were the Klippel measurements I’ve seen. They are tried and true and come from Pro companies that have been at it for a while. The 18n862 is legendary and an excellent music maker!

The SAF version is probably heavier since it’s a ferrite magnet if that matters to you. But I have no experience with it directly. LaVoce is an excellent company as well.

I have a 20' x 30' x 25'ceiling room. I'm looking for bass from the 30's to 200-300 hz depending on which mid/comp driver I'll be using. I've always built vented designs for bass, but am interested in the "transient response" I've read about with the large pro woofers in sealed enclosures. I have plenty of power and will be running Audiolense in an all active PC environment to handle time delay, crossovers, and shaping the response. My choices of mid/high are either the horn loaded 8" and comp driver from my JBL CS3115A's for 300-350 and up, or a pair of P.Audio BM-12CXA Coaxes run open baffle to handle 200 and up. I'm leaning toward the P Audio's as it will keep the JBL's together as a set, and I have another location I'm considering them for later. I'm in the US, so I have access to and really want to use B&C woofers. What size sealed box would you recommend for the 18TBW100, and if I decided on a 15" woofer instead, which would you recommend and how big of enclosure. 4 ohm drivers would be nice as my amplifiers support 4 ohms, and it would basically be free power. I'm more interested in getting the 30's - 200 or 300 right than trying to squeeze 20hz flat out of them.


Regarding the B&C 18TBW100, an excellent woofer in its own right, I would start with 3-4 cubic feet (that seems to be a nice standard for many 18 inch woofers in sealed enclosures) but I would model it as well, just to play with how much low frequency extension. Bear in mind, that your room will help a great deal. Look at the Loudspeaker Database, great info there which you can import to your simulator of choice. It’s hard to go wrong with sealed setups, except if you use an incredibly small enclosure volume, like 1 cubic feet for an 18 inch woofer!

That’s a fairly large room, and I would use multiple 18 inch woofers (each in individual sealed boxes) instead of 15 inch woofers. For support down to 16Hz, I have a Funk Audio 21 inch woofer in about 5 cubic feet which gets the job done with some DSP at 20Hz. It’s a wonderful woofer, underhung, neodymium magnet, non changing inductances over the entire travel, but, but… expensive! Surprisingly, the Funk added tremendous detail and weight even at an octave greater than 50Hz in my music applications.

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I'll be using these for bass duty in a 3 way active stereo config. The woofers will have a separate enclosure but will also serve as the base for the mids and highs, so I really want to limit it to a left and right woofer enclosure. You were right about the Funk Audio $$$'s. A little rich for my blood, but beautiful woodwork. I've been messing around with WINISD and Loudspeaker Database. I've imported files on a few drivers. Right now, it's a decision between the 18TBW100-4 and the Lavoce 184.03. I'll probably buy the TBW's just because they're available in 4 ohm.
Is there a rough guideline as far as where the QTC of the box should end up. I think I've read somewhere between .55 and .6, but I've read a lot lately.

Should I chose .707 or .577 when modeling a sealed enclosure in Winisd?
Most of that is hogwash once you place the sub in a room. Your measurements with REW in room trump everything. Basically, you get a smidgen deeper extension with 0.577 (if you need it) and less pass band ripple with 0.7. Don’t sweat that detail. Sweat the in room measurements. And it’s not like 0.577 sounds super tight compared to 0.7. That’s all handwaving subjectivism folklore based on theoretical ideals (which don’t exist in a real room that has room modes, etc….).

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.7 is the maximally flat Q while .557 is the most extended bass response. If you are using DSP I would go for .7 and use the DSP to get lower. With no EQ the .577 gets lower but starts rolling off much higher but since the DSP can fill the lower end in use the .7 so you don’t waste power putting back what the .7 already has and just boost the ultra lows.


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Use sealed, system (whole finished speaker) Q=0,5 for critical damping (i.e. no ringing) and EQ to taste... system Q=0,5 means one can not chose a Qts driver > 0,5...

The BMS driver is a very low distortion, SPL monster - but don't meet your budget...

Most of that is hogwash once you place the sub in a room......... And it’s not like 0.577 sounds super tight compared to 0.7. That’s all handwaving subjectivism folklore based on theoretical ideals (which don’t exist in a real room that has room modes, etc….).

Nowadays, mostly yes, but those of us that mostly built corner loaded systems it can matter, though overall these charts are sufficient.


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