I should be able to scare up all those out of my junk box.
In the end we will probably run them active most of the time.
dave
Was anybody sensible enough to save the original article, and have it available? I have the drivers and the crossover parts securely sequestered in the den, but the article no longer appears on Martin's site. TIA - Pat
Thanks, guys. As always, I could have looked a little harder, but I had followed my old link to the pdf, and that link no longer worked.
If your Mac has an Intel processor then you can use Vmware fusion to run Windows on it. Works a treat, I only use a Mac as well, but can still run all of the simulations on it under Fusion.
I've got an extra pair of ff85k's, and also a couple of plate amps... My main amp is low powered SET, so I think I'd have to use amps on the bass.
This looks like a cool project (since I have most of the parts). By amping the 15" speakers I'm going way off the original design this thread is about, but you might be able to answer this..
If going active for the bass, does all the resonance stuff for the bass speaker matter so much? (qts) Or is that more of a baffle geometry issue? I ask because a friend has a pair of 15" drivers w/ a big magnet, qts of .35, that I can have.
OTOH, those eminence are relatively inexpensive, so I can get them if needed...
I'd like to keep the baffle small (as small as the one the thread is about)
Thanks!
I'll add that what is confusing me, and I guess it's because it's OB specific, is the mention that the lower QTS drivers have a sharper low frequency roll off, when the specs for the drivers generally show the lower QTS drivers having a lower fs and frequency range. (at least for this speaker, and the other few datasheets I just looked at)
This looks like a cool project (since I have most of the parts). By amping the 15" speakers I'm going way off the original design this thread is about, but you might be able to answer this..
If going active for the bass, does all the resonance stuff for the bass speaker matter so much? (qts) Or is that more of a baffle geometry issue? I ask because a friend has a pair of 15" drivers w/ a big magnet, qts of .35, that I can have.
OTOH, those eminence are relatively inexpensive, so I can get them if needed...
I'd like to keep the baffle small (as small as the one the thread is about)
Thanks!
I'll add that what is confusing me, and I guess it's because it's OB specific, is the mention that the lower QTS drivers have a sharper low frequency roll off, when the specs for the drivers generally show the lower QTS drivers having a lower fs and frequency range. (at least for this speaker, and the other few datasheets I just looked at)
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The final response of an open baffle system is the convolution ogf the baffle response and the driver response... ie if the driver has a bump-up in response and the baffle is designed to have an equal & opposite bump-down, the combination will be flat.
dave
dave
is there a calculator around in which I can plug the speaker params, baffle size, etc?
I searched and found references to one, but can't find it.
I searched and found references to one, but can't find it.
Ive seen that, and it makes sense when you're using a passive xo... you'd need any help available to get that little boost at the low end. He also emphasizes several times, "when dealing with passive crossovers"
But, if you have power to spare with active, xover lower, turn up the power a little, I think you'd get a flat response to an even lower frequency.. (I'm just visualizing in my mind, based on the graphs on MJK's article)
Again, I know this thread is on passive, so I'm going a bit ot.. and maybe I'll just have to try for myself..
But, if anyone is experienced w/ active OB, let me know..
But, if you have power to spare with active, xover lower, turn up the power a little, I think you'd get a flat response to an even lower frequency.. (I'm just visualizing in my mind, based on the graphs on MJK's article)
Again, I know this thread is on passive, so I'm going a bit ot.. and maybe I'll just have to try for myself..
But, if anyone is experienced w/ active OB, let me know..
My answer was independent of active or passive. If you have a low Q woofer and a narrow baffle, then you get a rolled off response that needs LF boost (built into the hi-Q woofer). The best response you will get with a low Q woofer is the low Q woofer's natural response and to get that you need an "infinite" baffle.
Active with boost will work fine.
dave
Active with boost will work fine.
dave
I just finished this thread which covers exactly what I was wondering
http://www.diyaudio.com/forums/multi-way/152779-open-baffle-bass-dayton-ae-ib12.html
Im still thinking, for free (or maybe $20) for the low qts drivers, the foster plate amp has a little boost I can set (I'll have to see if it's enough to equalize things).
I guess it's worth a try.
http://www.diyaudio.com/forums/multi-way/152779-open-baffle-bass-dayton-ae-ib12.html
Im still thinking, for free (or maybe $20) for the low qts drivers, the foster plate amp has a little boost I can set (I'll have to see if it's enough to equalize things).
I guess it's worth a try.
The Foster plate amp also comes with all the instructions to do boost as you'd like. One of the plate amps we have used had 5 dB at 25 Hz which seemed to work well with 1/2 ft^3 (ignoring damping)/ Similar also seemed good to the measuring mic when i was using Beringer to experiment with Tysen XO
dave
dave
Hi. Guys. Quick question about plate amps. What would be the easiest way to match Tripath T-amp for Highs and mids and plate amps for lows.
Do I need a pre amp or is there a way to do the thing match volumes without it ?
Do I need a pre amp or is there a way to do the thing match volumes without it ?
You can wire up a resistor rig. You'd just need to find out the gain that your amps have, possibly adjust it a little, and then you can calculate a voltage divider network.
In theory at least 🙂 Should be cheap and cheerful anyways, so definitely worth a try.
So the idea is to connect one set of wires from T-amp to highs/mids and then attenuate the second set of wires and connect it to plate amps ?
PS. Would bass controll remain sufficient ?
PS. Would bass controll remain sufficient ?
That's what I would try. Something like that anyway. If you can keep the overall impedance to the source high enough, I am confident that the sound quality would be just fine.
Technically, if you match the voltage gain in the amps, you don't even need balancing resistors. I know that Tripath amp gain is pretty easy to change.
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