Answering my own question here, but who's counting?
Plugged into my PC, there's more gain on offer compared to my MP3, so the set up I have atm is loud enough.
Dave, you said at the start that you chose a HP filter for the FR drivers. Did you try it without a filter - I find it sounds better with my own - wondered if it applied to anyone else's??
Chris
Plugged into my PC, there's more gain on offer compared to my MP3, so the set up I have atm is loud enough.
Dave, you said at the start that you chose a HP filter for the FR drivers. Did you try it without a filter - I find it sounds better with my own - wondered if it applied to anyone else's??
Chris
anyone done an active FAST? I am experimenting with the Hypex AS2/100 modules and find them almost made for a high-end FAST. LR4 filtering wihout tons of copper, freedom in choosing the x-over without having o worry how to manage the baffle step, easy tuning of the character, Linkwitz Transform on the bass, etc. 1st tests are very impressive....
Yes we have. On occasion we still will use uFonken like this. It restricts dynamics and reduces the maximum levels you can play back up. Resistricting the bass the FF85 has to handle also improves its mid & top.
dave
Yes. Tysen is bi-amped. The UCD modules sound interesting, can you dial back the XO from LR? I am not a big fan of that topology.
dave
Ah yes, that's generally the trickiest part to get seamless - which is enough excuse for a lot of folks to avoid them altogether and just live with the "compromises" of limited bandwidth, frequency response linearity, SPL etc that go along with the single driver / wide-band ethos
A few years back, I built a couple of different 2 and 3-way systems with XO's designed via the whole LMS/LEAP routine. In the case of the 3-way (Heil AMT & stock woofer, Eminence Alpha 6" mid-range), the cost of only medium quality parts for the XO (Solen Hepta-Litz inductors / film caps, Mills non-inductive attenuation resistors) was greater than that of the mid-range driver. It modeled great on the 'puter and the customer was quite happy, but for my taste, there was something missing in terms of seamless coherency and transparency.
A couple of years later, a similar project with bipole Fostex FW227 woofers and AMT suffered much the same fate. When the original owner sold them back to me for parts cost, I tried to live with the full-zoot XO, and ultimately dialed it back to simple 2-way 1st order and notwithstanding obvious colourations, I found them much more dynamic and emotionally involving.
Back to something like the Tysen or any FAST system - there are probably more than a few ways to address the XO and amplification, much dependent on the selected drivers and synergy of /with amp(s) - particularly if actively bi-amping . Whatever works for you is obviously the right choice.
active FAST (er or semi-active )
Many could consider what I did if an active system is required.
Find a good quality plate amp with a good quality built-in X-over, and then buy two of them.
remember that 70% of the acoustic power of a full orchestra is in the timpani drum and the 2-sided bass drum.
If the plate amps can be set up for mono, then do that and run the X-over out to your main amp. It can be as little as 10 watts, assuming it is crossed high enough, and let plate amps do the rest. With the Jordan JX92S drivers in OB, I've had success with the X-over at (approx) 150 Hz, and a 180 watt (into 8 Ω) mono plate amp/ 10 watt per ch main amp. Way better than it should, given the relatively inefficient Jordans.
balance of the top end driver and sub are the toughest thing to get right,so I must be real lucky. I can't really answer how it almost always works out, but too many things generally worko out with not much thought , or else I have tin ears
.
Many could consider what I did if an active system is required.
Find a good quality plate amp with a good quality built-in X-over, and then buy two of them.
remember that 70% of the acoustic power of a full orchestra is in the timpani drum and the 2-sided bass drum.
If the plate amps can be set up for mono, then do that and run the X-over out to your main amp. It can be as little as 10 watts, assuming it is crossed high enough, and let plate amps do the rest. With the Jordan JX92S drivers in OB, I've had success with the X-over at (approx) 150 Hz, and a 180 watt (into 8 Ω) mono plate amp/ 10 watt per ch main amp. Way better than it should, given the relatively inefficient Jordans.
balance of the top end driver and sub are the toughest thing to get right,so I must be real lucky. I can't really answer how it almost always works out, but too many things generally worko out with not much thought , or else I have tin ears
.
Ahhhh - I think I understand where I went wrong when it sounded better without a HP filter.
I designed the filter (originally) for 8ohm speakers, but for the same frequency, so, too enthusiastic to think, I used the same components and made it from LP to HP, forgetting the impedance difference. This meant there's a gap between the woofers rolling off and the FRs comming in. I've (asked Dad to) order some XO parts, so I'll have them by Friday, then the real testing begins...
Chris
PS - the woofer I have chosen is the Visaton W130S 8ohm, which would give me an f3 of 42Hz in a 35L cab (for both speakers), and I'll mount them push-push. Frequency response attached.
I designed the filter (originally) for 8ohm speakers, but for the same frequency, so, too enthusiastic to think, I used the same components and made it from LP to HP, forgetting the impedance difference. This meant there's a gap between the woofers rolling off and the FRs comming in. I've (asked Dad to) order some XO parts, so I'll have them by Friday, then the real testing begins...
Chris
PS - the woofer I have chosen is the Visaton W130S 8ohm, which would give me an f3 of 42Hz in a 35L cab (for both speakers), and I'll mount them push-push. Frequency response attached.
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active filter or passive filter?
what do you mean with "dial back"? you can set the filter frequency and q in the DSP to anything you like. use 2 2nd order filters combined to obtain a 4th order. or use a 1st order filter. the nice thing is, that you can 1st correct with the DSP the response ot the driver to flat and do time allignment, and then apply a nice theoretical filterslope.
IINM, currently running passive line level on the Tysen (circa 330 Hz), and vintage active (Ace Audio) on a different bi-amped system.
It is actually more complex than that. You have to design with consideration of the impedance within a couple octaves of the XO point.
dave
We have tried active, passive LL, and buffered passive XOs in the active system.
The problem with active XOs is that you are introducing more active components into the signal chain. If you can get away with it, sneaking the filters in without adding any additional components leads to greater transparency.
the ability to set 1st, 2nd, or 3rd order filters.
dave
I might have a bit of an impedance problem.
The peak furthest right is the FR driver, and the large spike around 150Hz could cause trouble (an octave down on XO frequency). What might be done to sort this - I'd prefer to use a sealed box, but I'd be open to an MTL if this would help significantly.
Am I right in thinking that the two peaks furthest right (the woofer) will be OK for a LP filter at 300Hz?
I don't know a huge amount about crossovers
Thanks in advance
Chris
The peak furthest right is the FR driver, and the large spike around 150Hz could cause trouble (an octave down on XO frequency). What might be done to sort this - I'd prefer to use a sealed box, but I'd be open to an MTL if this would help significantly.
Am I right in thinking that the two peaks furthest right (the woofer) will be OK for a LP filter at 300Hz?
I don't know a huge amount about crossovers
Thanks in advance
Chris
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Yes. This is one part of why well-behaved drivers with flat impedance curves are highly desirable. They're much easier to get good crossover performance with. They also tend to be more stable in terms of Le(x), meaning that the crossover tuning doesn't change every time the cone moves.
Fair enough. I find the main problem is finances, and somewhere to get hold of the plate amps (almost none over here unless I pay import duties).
At the start of the thread, you suggested a MTL to flatten the impedance - would that help here? I noticed the impedance spike isn't as bad as with your driver, which goes past 80 ohms.
I have the option to bi-amp this set-up - should I try to go for active filtering aswell?
Chris
At the start of the thread, you suggested a MTL to flatten the impedance - would that help here? I noticed the impedance spike isn't as bad as with your driver, which goes past 80 ohms.
I have the option to bi-amp this set-up - should I try to go for active filtering aswell?
Chris
I've been thinking and talking to Dad about this - he has 3 options - new XO point, flatten impedance electronically, or just ignore the peak and hope it sounds good.
Revisions to the crossover can been made - the new XO will be around 400Hz, 2nd order for the woofer, 3rd order for the FR driver.
I checked the dispertion etc of the woofer, which is fine to 1kHz (2pi dispertion).
I've also considered an MTL system to sort out the impedance peak, but this would be a last resort really...
Any other ideas?
Chris
Revisions to the crossover can been made - the new XO will be around 400Hz, 2nd order for the woofer, 3rd order for the FR driver.
I checked the dispertion etc of the woofer, which is fine to 1kHz (2pi dispertion).
I've also considered an MTL system to sort out the impedance peak, but this would be a last resort really...
Any other ideas?
Chris
The red curve is unbaffled. The blue curve is in the aperiodic TL. Much flatter. I'm sure it could be flattened more, but we haven't taken the effort yet because we were bi-amping.
dave