Hi,
This seems like a great forum.I've been reading lots of posts,and found a great deal of helpful information,especially on dipoles,which is just what I need.So,now that I'm looking for some advice,I thought I'd ask here.
I have a pair of Lowther PM6's,which I'd like to use in a dipole design,where they'd cover everything above,say 200hz,or whatever would be suitable in that range.
I'm trying to decide on a suitable driver to cover the frequency range up to this point,and would be very grateful for your opinions.
To clarify things a little -
This would be a "2-way",actively driven,and equalized,system,loosely based on the Pheonix project,at Linkwitzlabs.com.
I've been working my way through Linkwitzlabs' material,and searching the various 'speaker forums as I go,but there are a couple of things that I can't find answers to.
eg : The Lowthers are very fast drivers,famous for their speed,in fact,but they sound thin from 200/250hz,on down - possibly even higher - even in a back-loaded horn.This is why I don't want to crossover at,for example,100hz.I hope that the woofers will add some body in this region.However,there don't seem to be many 12",or 15",units that can handle these freqencies well,without a very steep xover,which I'd like to avoid,if possible.
Other than the Lambda's,are there any other good,reasonably priced,15" woofers that don't break up before 1 or 2 khz? I haven't been able to find any.
Also,I can't find anything definite about the "speed" of these large units - some say there's nothing can keep up with the Lowthers,others say that a good driver can handle it easily.( some *really* expensive diy horn systems use 15" TAD drive units,which can be even more expensive than the Lowthers,so I guess it can be made to work,if you've got loadsamoney).
How bad would it sound ? ,(ie:a woofer not keeping up).
I imagine similar "speed-matching" problems might arise in mating a bass unit(s) to a good ribbon tweeter,though I'm not certain about this.If so,that might be a guide.Anyone confirm this? Did you find a woofer that worked well,in the end?
I've heard good things about the Lambda Acoustics drivers,and could just about afford 2 of these,at the reduced prices.Are these really as exceptional as claimed ?
Aother,possibly better,alternative was to use several less expensive 10" woofers per side,to handle 40 hz to 200hz approx.I thought I'd found the answer in the MCM 55 - 1555's,till I discovered that they only have an xmax of 1.5mm.I doubt this would be enough unless I had about a dozen per side.MCM have an even cheaper Aluminum 10" with an xmax of 4.5mm.Four of these per side might do,but how to tame the ringing?One thing I thought of - slitting the cone,then glueing the slits,like Scan-Speak do with their Slit-paper woofers,which are supposed to be great.But I don't know if this would work with a metal cone. Any ideas?
sfdoddsy,
Hi.I visited your site - and jonmarsh's - among others.You guys have built some amazing speakers.It's very encouraging to see what can be done.Steve,could you tell me the xmax of the 10" Focals you initially used in "BOB",just as a guide.You said that they only occcaissionally bottomed out,when rolled off at 40 hz,if I remember correctly.That would be fine for now.
So,overall,anybody have any suggestions?
Anyway,I think that's enough for now.Sorry to be asking so many questions,but I've no idea how else to find this info.
Thanks in advance for any help you can give.
BigSky.
This seems like a great forum.I've been reading lots of posts,and found a great deal of helpful information,especially on dipoles,which is just what I need.So,now that I'm looking for some advice,I thought I'd ask here.
I have a pair of Lowther PM6's,which I'd like to use in a dipole design,where they'd cover everything above,say 200hz,or whatever would be suitable in that range.
I'm trying to decide on a suitable driver to cover the frequency range up to this point,and would be very grateful for your opinions.
To clarify things a little -
This would be a "2-way",actively driven,and equalized,system,loosely based on the Pheonix project,at Linkwitzlabs.com.
I've been working my way through Linkwitzlabs' material,and searching the various 'speaker forums as I go,but there are a couple of things that I can't find answers to.
eg : The Lowthers are very fast drivers,famous for their speed,in fact,but they sound thin from 200/250hz,on down - possibly even higher - even in a back-loaded horn.This is why I don't want to crossover at,for example,100hz.I hope that the woofers will add some body in this region.However,there don't seem to be many 12",or 15",units that can handle these freqencies well,without a very steep xover,which I'd like to avoid,if possible.
Other than the Lambda's,are there any other good,reasonably priced,15" woofers that don't break up before 1 or 2 khz? I haven't been able to find any.
Also,I can't find anything definite about the "speed" of these large units - some say there's nothing can keep up with the Lowthers,others say that a good driver can handle it easily.( some *really* expensive diy horn systems use 15" TAD drive units,which can be even more expensive than the Lowthers,so I guess it can be made to work,if you've got loadsamoney).
How bad would it sound ? ,(ie:a woofer not keeping up).
I imagine similar "speed-matching" problems might arise in mating a bass unit(s) to a good ribbon tweeter,though I'm not certain about this.If so,that might be a guide.Anyone confirm this? Did you find a woofer that worked well,in the end?
I've heard good things about the Lambda Acoustics drivers,and could just about afford 2 of these,at the reduced prices.Are these really as exceptional as claimed ?
Aother,possibly better,alternative was to use several less expensive 10" woofers per side,to handle 40 hz to 200hz approx.I thought I'd found the answer in the MCM 55 - 1555's,till I discovered that they only have an xmax of 1.5mm.I doubt this would be enough unless I had about a dozen per side.MCM have an even cheaper Aluminum 10" with an xmax of 4.5mm.Four of these per side might do,but how to tame the ringing?One thing I thought of - slitting the cone,then glueing the slits,like Scan-Speak do with their Slit-paper woofers,which are supposed to be great.But I don't know if this would work with a metal cone. Any ideas?
sfdoddsy,
Hi.I visited your site - and jonmarsh's - among others.You guys have built some amazing speakers.It's very encouraging to see what can be done.Steve,could you tell me the xmax of the 10" Focals you initially used in "BOB",just as a guide.You said that they only occcaissionally bottomed out,when rolled off at 40 hz,if I remember correctly.That would be fine for now.
So,overall,anybody have any suggestions?
Anyway,I think that's enough for now.Sorry to be asking so many questions,but I've no idea how else to find this info.
Thanks in advance for any help you can give.
BigSky.
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