DIY 110 sub and 210 full range cabs

[Sundogue]

I have a Superfly amphead that puts out 250 watts per side into 4 ohms (each side)

I have an idea for 110 and 210 cabs with separate purposes. One 110 sub and one full range 210 with a tweeter. They would be stacked in a vertical alignment and built using 1/2" ply with bracing.

The 110 cab would be more like a sub using an Eminence BP102 - 4 ohm bass speaker built to maximize the capabilities of the BP102. There will be no crossover, just using the limited range of the BP102 for it's own purpose...the "sub" part of the cab. This will be driven by one side of my amp. I'm not looking for a really small cab...I want to make the cab as large as needed (and tuned) for the single BP102 to act like a sub.

The upper, 210 part of the cab would use two (more full range) Peavey 121-8 Sheffield 8 ohm bass speakers (wired to 4 ohm) in an ideal size/tuned cab, along with a tweeter (utilizing the existing crossover that came with the tweeter and speakers). I'd probably use the existing boat anchor Peavey cab for the dimensions but build it lighter. This cab would be driven by the other side of my amp.

This would give me a 110 sub under a 210 cab for three 10's on top of each other, but with each cab having a separate purpose.

I know there are more ideal cab designs out there. I'm just playing around with an idea for some small cabs using what I have lying around. Part of my reason for doing this is the BP102's really need more cab volume to shine and loading two in a cab makes for a much bigger cab, so why not just build a decent size 110 for a single BP102? I want to keep both cabs at 4 ohms.

This is just intended to be something fun in creating some smaller cabs that give me the most for their size.

Any thoughts or suggestions on this?

 

[billfitzmaurice]

You've got it backwards. A sub requires at least four times the power capability, Vd and cabinet size than the top above it. As for cab size, if it's going to go low and go loud it can't be small. There's no getting around that cold hard fact. The top can be small, and it absolutely must be sealed if you're running with no crossover, otherwise the top and sub will be out of phase below the top's tuning frequency and they'll cancel each other out.

 

[gerryjazzman]

I know there are more ideal cab designs out there. I'm just playing around with an idea for some small cabs using what I have lying around. Part of my reason for doing this is the BP102's really need more cab volume to shine and loading two in a cab makes for a much bigger cab, so why not just build a decent size 110 for a single BP102? I want to keep both cabs at 4 ohms.

What Bill said about the top. For the sub you might want to consider one of Bill's designs. Probably the best would be the T39: http://www.billfitzmaurice.com/T39.html. Not exactly small but quite manageable if you build it in the 14 inch width option. The BP102 is a recommended driver for the cab. Not sure about running that without a crossover though. Bill can chime in on that one. A T24 http://www.billfitzmaurice.com/T24.html is another option that is a bit smaller and trades off sensitivity for a bit more low end extension. Even though the T24 is recommended more for recorded music / DJ type of service a number of people have used them succesfully as a bass guitar sub for backline use. One of these two has an option for a passive crossover that is OK for backline use (forget which one, might be OK with either). Again Bill may put his two cents in here.

 

[Sundogue]

Perhaps using the term "sub" is a bit of a misnomer for what I'm intending.

Say I had the Peavey 210 cab with the tweeter already but it just really didn't give me as much lows as I wanted (which isn't to say I want huge thundering lows that knock me off the stage...just some added depth that the Peavey's don't give me).

How big of a cab would you recommend for a single BP102 to maximize it's low end capability (knowing it needs a mid range driver with it for a full range cab...but in this case not needed as I have the other 210 that fills that in).

I always hear about the BP102 and the comments always come in the way of..."You'll need a mid-range driver with it because it can only handle the low end."

Well, in this case I'm not adding a mid-range speaker to the BP102 cab...I'll be adding a whole 'nother 210 cab with mid range drivers that don't go as low as the BP102.

So, again...any thoughts on what the best size cab (cu. ft.) would be to maximize the low end? I'm thinking a 210 size cab, but just the one BP102 alone in it.

I should add...just because I want my "sub" (as it were) to be a 110 cab doesn't mean I want it to be some standard tiny 110 cab. I'd just like it's footprint to match the 210 on top.

 

[Sundogue]

You've got it backwards. A sub requires at least four times the power capability, Vd and cabinet size than the top above it. As for cab size, if it's going to go low and go loud it can't be small. There's no getting around that cold hard fact. The top can be small, and it absolutely must be sealed if you're running with no crossover, otherwise the top and sub will be out of phase below the top's tuning frequency and they'll cancel each other out.

Four times the cabinet size of my 210 cab would be 16 cubic feet!

I don't think so. I've read where the BP102 should have a 2.5 to 4.5 cu.ft. cab volume.

 

[alexclaber]

You could design a bandpass cab for the BP102 to give you a big hump in output around say 60Hz to fill in under the Peavey. That'll get you higher sensitivity than a ported cab from a smaller cab than a horn at the expense of bandwidth.

Alex

 

[gerryjazzman]

Also check the Eminence site for their suggested cabinet designs under their Resources section (I think). For each driver they have a PDF document with several designs, one of which might be close to what you're looking for. They would be just sealed or ported designs, nothing more exotic.

 

[Standalone]

wait... is there a crossover here? You're going to be sending the same frequencies to both cabs... bass and highs will be coming out of both, only governed by the particular response profile of the cabs and speakers. It might sound great, but it would not be a "sub..."

why not build two 110's and put a tweeter in one? There are many tweeter options-- you can put one in that isn't harsh. Or what about a 110 + 6" midrange and a 110 + tweeter? That's what I would do. Then you'd have two cool cabs with unique voices that could be useful in different situations on their own, depending.

edit: I have a 4 ohm yamaha 110 that has a great bass response (I think it uses the same driver you mention?) and an 8 ohm 2x6 flite cab with a dome tweeter. This is great for my 800RB which has two amps, one 300 watt 4 ohm amp and a 100 watt 8 ohm amp. I get a lot of different sounds, both running full range and running in biamp/crossed over mode.

here's a picture:

both cabs have a similar low level buzz that makes me think they have x-over issues, but once I replace the x-overs, I'll run it live to test it out. So far, I think it sounds best full range.

 

[billfitzmaurice]

Four times the cabinet size of my 210 cab would be 16 cubic feet!

For the above 150 Hz bandwith required you don't need two tens in a 4 cu ft reflex cab. One ten would do, and it would only need a one cubic foot sealed cab.
If you want a sub capable of keeping up with your two tens in their current cab there are two ways of doing so, either with one BP102 in a horn loaded cab of 10 to 12 cubic feet or two BP102s in a reflex cab of about 8 cu ft. Your current cab will still be twice the size it needs to be, though.

 

[bgavin]

Why not go 3015LF in a 5 cubic foot cab? It has an F3 of 43 Hz compared to 31 Hz for BP102, but makes a whole lot more noise.

 

[Sundogue]

Thanks for the comments/ideas guys.

I want to use what I have, so no other speakers exist for options at this time.

As far having to have a true dedicated sub, I really do not need that. I have a 210 cab that sounds great and is plenty loud for my needs. There are some gigs where I'd like to add another, preferably one that provides more bottom end.

Here's the scenario again. I have a Superfly which puts out 250 watts into a 4 ohm load (per side). I have two 4 ohm BP102's, so any cab that has that speaker in it, I want to only have one (4 ohm cab). The other speakers are Peavey Sheffields. They are 8 ohm and I want them in the top 210 (4 ohm cab).

I know some will say "most speakers today are 8 ohm", or "You don't need a 4 ohm cab as an 8 ohm cab will still be plenty loud". "Loud" is subjective, and I want two 4 ohm cabs.

So what I am left to work with is two 8 ohm Sheffields in one cab and one 4 ohm BP102. Now, I have had BP102's loaded in a tweeterless cab before. They are more of a "sub" speakers as they do not go above 2000Hz. So to my thinking, why not put one of those 4 ohm speakers in a cab without a tweeter and just let them be what they are...a speaker that handles 200 watts from 40Hz to 2000Hz?

What I find interesting is that if I had stated that I had a 210 cab that I wanted to keep using and just wanted to put a cab under that...only one that handled the bottom end more, so I had a small stack, I would have gotten tons of recommendations for a cab with a bigger bottom end to put under my 210. But I asked about building one myself using BP102's and suddenly I "can't" or "shouldn't" even consider putting a cab under my 210.

So, again...if I were to use a single BP102...what would you choose for cabinet volume or type to maximize the low end the BP102's handle? I'm not looking for terribly small...and really anything that would match the footprint of my 210 cab (vertical) would be ideal.

I'm thinking of building two lightweight cabs...one an exact copy (internal dimensions) of the boat anchor cab of the Peavey 210 for the top...and perhaps the same size cab for the single BP102 for the bottom. The outside dimensions of this cab is 24" high X 18" wide X 17" deep. Internal dimensions will be altered to gain the low end I want from the BP102.

So would a single BP102 in that size cab (tuned to 39Hz) be a good cab for more low end response to put under my 210 (more full range) cab? I just want to be able to add this "sub" to the 210 on bigger gigs where I may not be close enough to the PA sub that currently gives me all the low end I could want onstage. Just a little more bottom end. I'm not expecting it to match the volume of the 210, just give a bit more low end. I don't want a PA sized sub onstage and to me, a standard 210 cab is still small (and if I build it myself, it will most certainly be light!).

NOTE: Anyone who suggests another cab (i.e. - ACME, etc.) or speakers hasn't been following along. FOCUS people.

 

[Sundogue]

For the above 150 Hz bandwith required you don't need two tens in a 4 cu ft reflex cab. One ten would do, and it would only need a one cubic foot sealed cab.
If you want a sub capable of keeping up with your two tens in their current cab there are two ways of doing so, either with one BP102 in a horn loaded cab of 10 to 12 cubic feet or two BP102s in a reflex cab of about 8 cu ft. Your current cab will still be twice the size it needs to be, though.

I've noticed some people are building your Omni 10 in a "tall" version. Looks interesting. Do your plans include this mod, or are they just going off on their own? Also, I find it interesting that you no longer recommend BP102's in your Omni 10, yet the reviewer states that what he uses and loves it (subjective of course).

 

[alexclaber]

If you're willing to go bigger a 6th order bandpass cab with front chamber 2 cu.ft @ 70Hz and rear chamber 3 cu.ft @ 40Hz will get you 96dB sensitivity, F3 @ 43 and 88Hz.

Alex

 

[will33]

I'm thinking of building two lightweight cabs...one an exact copy (internal dimensions) of the boat anchor cab of the Peavey 210 for the top...and perhaps the same size cab for the single BP102 for the bottom. The outside dimensions of this cab is 24" high X 18" wide X 17" deep. Internal dimensions will be altered to gain the low end I want from the BP102.

So would a single BP102 in that size cab (tuned to 39Hz) be a good cab for more low end response to put under my 210 (more full range) cab? I just want to be able to add this "sub" to the 210 on bigger gigs where I may not be close enough to the PA sub that currently gives me all the low end I could want onstage. Just a little more bottom end. I'm not expecting it to match the volume of the 210, just give a bit more low end. I don't want a PA sized sub onstage and to me, a standard 210 cab is still small (and if I build it myself, it will most certainly be light!).

NOTE: Anyone who suggests another cab (i.e. - ACME, etc.) or speakers hasn't been following along. FOCUS people.

Those diminesions assuming 3/4" material and a 1" baffle recess works out to about 3.1cu.ft. before any bracing, driver or ports so maybe 2.8 or so net volume, maybe a little more using 1/2" material and keeping the outside dimensions the same. Your 39hz tuning keeps the midbass hump out of it and lets the BP102 easily hit 40hz according to WinISD. It will just do quietly compared to the peavey 210. I think the guys above are looking at it from the angle of getting the sub up to the SPL of the top, hence the pair of BP-102's and/or the horn loading and using a 110 top. Your way seems more akin to sticking a 15 under a loud 410 on a smaller scale. Doesn't add much volume to the rig but still sounds noticably deeper just because the bottom cab although much quieter is putting out lows the top doesn't have. Your rig should sound noticably deeper, just not much louder. You'd probably get some bass feeling through your feet if you're standing close to the rig. If you already have all this stuff on hand you wouldn't be out much to give it a shot, just don't expect much volume increase, just a deeper sound. I'd also layout the baffle so you could convert it to a more typical 210 if this ends up not being what you want. Just an idea.

The BP102's sensitivity is closer to a car audio or home theater sub than it is live sound so any change in sound would strictly be for yourself as a deep stage monitor but you're running with PA support anyway. Just don't know if it'd even be enough of a difference to justify the sweat equity.

 

[billfitzmaurice]

I've noticed some people are building your Omni 10 in a "tall" version. Looks interesting. Do your plans include this mod,

No. Being only 20 inches wide to begin with there's no need for a narrower/higher version IMO.

Also, I find it interesting that you no longer recommend BP102's in your Omni 10, yet the reviewer states that what he uses and loves it (subjective of course).

The original Omni 10 prototype was loaded with BP102s. That was about a year before the Deltalite II 2510 and S2010 became available, both of which work so much better that I removed the BP102 from the list of drivers recommended for that cab. I still recommend the BP102 but only in subs, not full range boxes.

The BP102's sensitivity is closer to a car audio or home theater sub than it is live sound

The low frequency sensitivity of the BP102 is higher than most tens, and its T/S specs bear no resemblance to autosound or HT woofers. The only reservation with the BP102 is that is has lower midrange sensitivity than typical tens, so it's best employed only up to 300 Hz or so.

 

[Sundogue]

If you're willing to go bigger a 6th order bandpass cab with front chamber 2 cu.ft @ 70Hz and rear chamber 3 cu.ft @ 40Hz will get you 96dB sensitivity, F3 @ 43 and 88Hz.

Alex

That looks interesting. So a 6th order bandpass essentially only has ports with no exposed speaker? I've never built one, but in WinISD it appears as if the back chamber is like a normal cab, but then the front chamber contains the sound from the speaker and only allowing it to come out another port. Is that correct?

 

[Sundogue]

No. Being only 20 inches wide to begin with there's no need for a narrower/higher version IMO. The original Omni 10 prototype was loaded with BP102s. That was about a year before the Deltalite II 2510 and S2010 became available, both of which work so much better that I removed the BP102 from the list of drivers recommended for that cab. I still recommend the BP102 but only in subs, not full range boxes.

The low frequency sensitivity of the BP102 is higher than most tens, and its T/S specs bear no resemblance to autosound or HT woofers. The only reservation with the BP102 is that is has lower midrange sensitivity than typical tens, so it's best employed only up to 300 Hz or so.

Good to know. Thanks.

The reason the "tall" Omni looked intriguing was that it was narrower and thus fit in the back seat of my car better (weird angle at the door).

 

[will33]

No. Being only 20 inches wide to begin with there's no need for a narrower/higher version IMO. The original Omni 10 prototype was loaded with BP102s. That was about a year before the Deltalite II 2510 and S2010 became available, both of which work so much better that I removed the BP102 from the list of drivers recommended for that cab. I still recommend the BP102 but only in subs, not full range boxes.

The low frequency sensitivity of the BP102 is higher than most tens, and its T/S specs bear no resemblance to autosound or HT woofers. The only reservation with the BP102 is that is has lower midrange sensitivity than typical tens, so it's best employed only up to 300 Hz or so.

Poor choice of words, just saying it trades SPL for playing deep, not sure if a single one in a regular ported box will get him what he wants. May need to put the same size/footprint deal further down the list of priorities. Crossing over would be optimal but might not get in the way if keeping everything aligned vertically. How much work/expense do you want to put into this? Bandpass or horn loading would bring the SPL, how's your carpentry skills?

 

[alexclaber]

That looks interesting. So a 6th order bandpass essentially only has ports with no exposed speaker? I've never built one, but in WinISD it appears as if the back chamber is like a normal cab, but then the front chamber contains the sound from the speaker and only allowing it to come out another port. Is that correct?

Yes. And by restricting the bandwidth you can increase both the sensitivty and the maximum output - the reference sensitivity of a BP102 is about 91Hz so the bandpass configuration is getting you another 5dB and the ports reduce cone excursion so the speaker can handle more power. Compared to a 3 cu.ft 40Hz reflex cab max SPL at 60Hz is more than 6dB higher.

Not something I'd normally consider but as you're looking for a cab to simply add bottom to your existing cab then this should do the job. The alternative would be a Titan 39 which has similar sensitivity (though wider bandwidth) but I don't know how well cone excursion (and thus power handling) is controlled with the relatively small mouth of a single slim horn cab.

Also the bandpass design acoustically filters the output so distortion should be lower and you can get away without a crossover (only for a bass rig though, not for hi-fi!)

Warwick has made bandpass bass cabs for a while, the latest being the Jonas Hellborg big cab.

Alex

 

[Sundogue]

Poor choice of words, just saying it trades SPL for playing deep, not sure if a single one in a regular ported box will get him what he wants. May need to put the same size/footprint deal further down the list of priorities. Crossing over would be optimal but might not get in the way if keeping everything aligned vertically. How much work/expense do you want to put into this? Bandpass or horn loading would bring the SPL, how's your carpentry skills?

My carpentry skills are excellent. I have all the materials I'd need lying around and this kind of thing is fun for me.