DIY 110 sub and 210 full range cabs

[Sundogue]

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

Thanks so much for the idea. I think I might try this.

 

[will33]

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

Then cool. A bandpass or a titan are going to be big boxes but will get you what you need. I was going to say a delta12LF in a box the size of your 210 would probably put in whatever bottom you're lacking but that wouldn't meet the goal of using the components you have on hand. I haven't had good luck finding those in 4ohm or 16ohm either.

 

[Sundogue]

Then cool. A bandpass or a titan are going to be big boxes but will get you what you need. I was going to say a delta12LF in a box the size of your 210 would probably put in whatever bottom you're lacking but that wouldn't meet the goal of using the components you have on hand. I haven't had good luck finding those in 4ohm or 16ohm either.

Well, big doesn't always translate into heavy. I'm very good at building light boxes that are braced.

I have two 115 neos that are only 27 lbs.each. I wanted to see what I could come up with using my tens.

 

[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

I assume I build the bandpass cab as if I were building two cabs...tune the front "cab" (chamber) to 70Hz and then the back "cab" (chamber) to 40 Hz.

I'm curious...how much low end "sound" comes out of those ports? I'm so used to front loaded ported cabs with resonant ports that have almost nothing coming out the port (as far as usable volume anyway).

This should be fun and interesting.

 

[will33]

Well, big doesn't always translate into heavy. I'm very good at building light boxes that are braced.

I have two 115 neos that are only 27 lbs.each. I wanted to see what I could come up with using my tens.

+1 on the weight. My homebrew cabs are a 210, 212, 115 and 118 and I'm slowly, a piece at a time on weekends rebuilding all but the 18 with braced 1/2" and making some ergonomic improvements after schlepping these around for a while. Be interested to know how this turns out for ya.

 

[Sundogue]

Well, it may be a while before I build this. Winter is the best time for me as I don't have any outdoor hobbies in the winter (unless you count shoveling and snowblowing hobbies).

I'm also going to look into bandpass cabs a bit more, so if anyone has built one before or anyone has any suggestions for a 6th order bandpass cab, feel free to share.

4th order cabs appear to be easier to build, but essentially a 6th order bandpass cab is like two cabs, each with their own tuning.

For anyone who might know, from what I understand of port tuning, only a specific frequency is coming out the port, so how does a bandpass cab give anyone a "range" of useable frequencies? Say, like from 40Hz to 90Hz for example, if you only have ports tuned to those frequencies?

 

[alexclaber]

For anyone who might know, from what I understand of port tuning, only a specific frequency is coming out the port, so how does a bandpass cab give anyone a "range" of useable frequencies? Say, like from 40Hz to 90Hz for example, if you only have ports tuned to those frequencies?

A tuned port provides a narrow band (about an octave at most) of output peaking at the tuning frequency. This design is tuned to 40Hz and 70Hz and the response is almost flat between these frequencies, so as the output from the 70Hz port drops so the output from the 40hz port makes that up.

Inspired by this I did some experimenting with the 3015LF driver I use in The Big One to see if I could design a bandpass sub with very high output. Not very successful! I think the BP102 performs well in a bandpass cab because it has quite low Fs and high Qts (so it isn't very damped at lower frequencies) and comparatively low Vd (so the reduced cone excursion is particularly beneficial).

Alex

 

[Sundogue]

A tuned port provides a narrow band (about an octave at most) of output peaking at the tuning frequency. This design is tuned to 40Hz and 70Hz and the response is almost flat between these frequencies, so as the output from the 70Hz port drops so the output from the 40hz port makes that up.

Inspired by this I did some experimenting with the 3015LF driver I use in The Big One to see if I could design a bandpass sub with very high output. Not very successful! I think the BP102 performs well in a bandpass cab because it has quite low Fs and high Qts (so it isn't very damped at lower frequencies) and comparatively low Vd (so the reduced cone excursion is particularly beneficial).

Alex

Let's say I forgo the bandpass cab and just build a front loaded cab for the single 4 ohm BP102. If it were sufficient size (which typically 110, or even 210 cabs are not), would it give the BP102 more low end? I do know that the BP102's like more room than they are usually given, but what would be an ideal cab size to maximize the BP102's low end features?

If you still think the bandpass is best, cool. But if I didn't go the bandpass route, what size cab/tuning would make the speaker work best?

I still am intrigued with the bandpass idea, but others in another thread bring up that it would be muddy. I don't know why if the ports were designed to accentuate the lows. I don't think of mids or highs as producing "mud".

 

[alexclaber]

Let's say I forgo the bandpass cab and just build a front loaded cab for the single 4 ohm BP102. If it were sufficient size (which typically 110, or even 210 cabs are not), would it give the BP102 more low end? I do know that the BP102's like more room than they are usually given, but what would be an ideal cab size to maximize the BP102's low end features?

I think you'd be best served by trying different designs in Win ISD Pro. Bear in mind that you have 250W available so you want to maximise both sensitivity and power handling below 100Hz. The best I could find was that bandpass design but I didn't spend that long fiddling.

Alex

 

[Sundogue]

I think you'd be best served by trying different designs in Win ISD Pro. Bear in mind that you have 250W available so you want to maximise both sensitivity and power handling below 100Hz. The best I could find was that bandpass design but I didn't spend that long fiddling.

Alex

Thanks. I've been playing around with WinISD and "Pro" a bit more of late.

 

[DBM]

I'm curious if you have made any progress on this project. I just joined this forum today and have been reading it all day long.
I noticed that back on 2006, you installed the two BP102's in the largish 210 cabinet and were very happy with the sound. Why are you not still running that 210 cab with the BP102's in it? Or did the low sensitivity drive you nuts?

I built a 6th order bandpass enclosure ~9 years ago using a single 10" driver. The enclosure was for an old coworker for use in his car. It indeed was very efficient over a narrow frequency range but was lacking definition. He ended up cooking the driver by pushing it too hard. Driver distortion is not easy to hear outside of a bandpass enclosure.

Anyways, I'm looking forward to hearing how this project is progressing....if it has progressed at all.

To the rest of the TB forum, my apologies for digging up a month old thread.

Regards,
-Dennis

 

[Sundogue]

I haven't done much with it as my gigging schedule picked up a lot.

I only mess around with cab builds in the winter when the band schedule it pretty light.

I also just got a new bass, and my current rig is still killer and working great for me (Superfly head with two 115 neo's that only weigh 27 lbs. each).

The 210 cab I put the BP102's in was just too heavy though it did sound great. Yes, I found that in the long run, the sensitivity was a bit too low for some gigs.

Now I'm just looking for a great practice rig I can leave at band practice. We'll see what happens with those BP102's.