Midbass horn: how to solve the range below it?

[LewinskiH01]

I really appreciate this discussion. Making me reconsider several angles. The last few posts are more geared towards the midrange horn discussion which is more in line with my other thread on the subject: http://www.diyaudio.com/forums/mult...-design-cone-driven-201-a-27.html#post5052692

Please let's continue the midrange discussion there. It is helpful for me to have one place to go back and re-read your posts regarding midrange, and another for the midbass to bass transition. Thank you!!

Regarding bass options below the midbass horn, IB is not an option in my room. Bass horn maybe, but I get the feeling it would end up being a very large horn and direct radiators below it...maybe cut the WAF talk an avoid the horn altogether?

So I'm probably down the path of stacking several 15" per side (4 or 5, maybe) either as direct radiators or have maybe 6 in SLOBs and play them up to about 150Hz. The midbass horn with the 8PE21 can go lower than 150Hz, but on Hornresp it looks like the throat impedance at around 130Hz will be generating large ripples, so maybe safer to assume a higher xo.

How much of an issue do you think it will be to xo at 150Hz to a separate tower sitting by the midbass horns?

As wheigher suggested earlier, sticking with the dual 10" sealed direct radiators per side xo at 80Hz plus a stack of 3 to 4 sealed subs per side is definitely a lot easier. Makes me wonder if the sound is going to be that much better.

 

[Scott L]

sad about your IB decision

Really to bad to hear about your I.B. decision. Really, is there no place to find the volume, as I suggested in my earlier post ?

A SLOB is probably much better at mid bass, then deep bass. Deep bass, that sounds natural, can only be done by moving lots of cone area, in an arrangement that avoids the short circuit of any kind of open baffle.

You might actually be better off just adding more of the Rythmic subs that you are already using. You might need 3 or 4 units to provide enough room pressure to sound balanced with the rest of the system.

 

[AllenB]

The midbass horn with the 8PE21 can go lower than 150Hz, but on Hornresp it looks like the throat impedance at around 130Hz will be generating large ripples, so maybe safer to assume a higher xo.

Bandwidth decisions are a complex part of designing with this driver. It works on a LeCleach style horn handling the lower end of the midrange where it loads well, and sounds good but narrows the higher frequencies so higher midrange might be asking for a different horn style, one where the pattern is better considered but the low end falls off..and the compromises begin..

 

[LewinskiH01]

Bandwidth decisions are a complex part of designing with this driver. It works on a LeCleach style horn handling the lower end of the midrange where it loads well, and sounds good but narrows the higher frequencies so higher midrange might be asking for a different horn style, one where the pattern is better considered but the low end falls off..and the compromises begin..

FWIW, for my planned system midbass would go up to 400 or 500Hz, then the midrange horn would take over. Sounds like the ideal bandwidth for this driver would be 200 to 700/800Hz...oh well. This is why I'm asking about bass solutions below this midbass horn. Alternatively I could go to a B&C 12", which models lower on the horn, but then I'm told the 8PE21 is MUCH better above 250Hz or so. Tradeoffs...of course.

 

[LewinskiH01]

Really to bad to hear about your I.B. decision. Really, is there no place to find the volume, as I suggested in my earlier post ?

A SLOB is probably much better at mid bass, then deep bass. Deep bass, that sounds natural, can only be done by moving lots of cone area, in an arrangement that avoids the short circuit of any kind of open baffle.

You might actually be better off just adding more of the Rythmic subs that you are already using. You might need 3 or 4 units to provide enough room pressure to sound balanced with the rest of the system.

Unfortunately I can't see making IB happen, unless I do major modifications which will trigger an argument I don't think is worth having. I live in an apartment and the system is in the living room...don't have as much freedom to modify as I wished.

OK, so SLOBs aren't a good idea. Maybe several subs in sealed boxes...adding up to a significant cone area...Have to say 3 or 4 units sounds less than what I was expecting. Simpler than I thought then.

 

[whgeiger]

Lease Breaker

Unfortunately I can't see making IB happen, unless I do major modifications which will trigger an argument I don't think is worth having. I live in an apartment and the system is in the living room...don't have as much freedom to modify as I wished.

OK, so SLOBs aren't a good idea. Maybe several subs in sealed boxes...adding up to a significant cone area...Have to say 3 or 4 units sounds less than what I was expecting. Simpler than I thought then.

describes the acoustic power capability of the system you are pursuing. When I turn up my two Velodynes, I get an unfriendly response from my neighbors and none of us are apartment dwellers. I suspect that in Argentina like in the US, there are legal covenants that prohibit generation of acoustic disturbances. Unless you plan on moving to a rural area, your acoustic nirvana is going to be civilly limited to an output that can be adequately provided by say two 15" servo controlled subwoofers.

WHG

 

[AllenB]

Sounds like the ideal bandwidth for this driver would be 200 to 700/800Hz...

I have used it to 1200Hz without issue. I suspect it could go another octave but my tweeters go down to 700Hz so it doesn't matter to me.

On the low side, JLH used the 8PE21 in a tapped horn sub to 40Hz and reported a good output level. Not likely in the circumstances you and I choose to use it and with low Xmax, not much chance of pushing it but it will play very loud all the same.

 

[SpeakerBob]

I'm currently using a pair of labhorns from 80Hz down, and am looking to downsize the system.

I've been considering a 2 way solution with a large ported box 'hidden' in the corner running 30Hz and below crossed to 3 small boxes placed around the room to smooth out room modes. If I had a larger budget I'd use 3x servo 12" subs. I'm probably going to end up using 2x10" per box PPSL.

Rob.