Okay...back to LX5 and first impression is that the midrange balance is better and the lower bass has better presence, but there may be a slight upper mid-bass emphasis. I will report more on the tweaking. I await the L-pads to adjust the LE85 level more precisely and will compare the N1200S and the LX5 once that is in place.
Question for the crossover experts: Will the use of a Zobel (conjugate RC) designed for a particular bass driver with another bass driver change the frequency response curve of the crossover/driver combination? The Zobel in the LX5 (500Hz, designed for use with the LE15A) is a 13.5uF cap + 10 ohm resistor across the LF driver. The Zobel in the N1200S (1200Hz, designed for use with the D130) is a 12uF cap + 15 ohm resistor. What I notice is increased bass level using the LX5 with the D130, compared to the N1200S. Actually sounds better balanced and more extended with the LX5, despite the fact that it is the incorrect crossover.
I didn't try to simulate it, but I would expect the answer to be something like
"certainly, but not significantly."
...but the crossover change 500->1200, the spectral balance of just the 15"
driver will change... which could lead one to "hear" a change in bass
emphasis. If listening to the entire system (as opposed to just the bass
driver), the change in characteristics of a 15" driver vs. compression
driver/horn in the 500-1200Hz range could also change the perceived system
balance (e.g., more or less pronounced midrange emphasis).
Seems like you have a strong preference for the LX5 in this system. Unless
you have an interest in crossover design, I'd sell the 1200S and buy some
nice source material (CD/vinyl/whatever) to enjoy the speakers with.
ah... and I make no claim to being a "crossover expert"... there are folks
that have direct experience (some decades) and earn a living in that capacity.
...Over the years I have listened to two bass horn systems on many occassions and each produces great sound. These include:
1. Altec VOTT in bass horn trim with the cast HF horns mounted "nudie style" on top
2. Klipsch in the corner horn cabinet, which is similar to the one below except in a taller CAB, I believe
Obviously, the Klipsch style cabinet is more pleasing to the eye, so that might be one consideration if you are married to a person who HATES big speaker boxes in her (??? Huuu) home, for example.
Personnally, I think both designs are very distintive and provide an interesting showcase for discussion by visitors who might come to your home for a visit.
Thanks grumpy. I have lots of music to enjoy...was mostly interested in learning a bit more about the possible effects of the Zobel network. Yes, the perceived balance is affected by the characteristic of the D130 around the region of the higher crossover point. I seem to recall the D130 was originally designed for musical instrument reproduction (e.g. guitar) and perhaps the rising characteristic with a peak in the 1-3KHz region was to bring out the midrange presence in live performance. This is not quite what I want in a home system, so the LX5 may work better.Originally Posted by grumpy
I didn't try to simulate it, but I would expect the answer to be something like
"certainly, but not significantly."
...but the crossover change 500->1200, the spectral balance of just the 15"
driver will change... which could lead one to "hear" a change in bass
emphasis. If listening to the entire system (as opposed to just the bass
driver), the change in characteristics of a 15" driver vs. compression
driver/horn in the 500-1200Hz range could also change the perceived system
balance (e.g., more or less pronounced midrange emphasis).
Seems like you have a strong preference for the LX5 in this system. Unless
you have an interest in crossover design, I'd sell the 1200S and buy some
nice source material (CD/vinyl/whatever) to enjoy the speakers with.
ah... and I make no claim to being a "crossover expert"... there are folks
that have direct experience (some decades) and earn a living in that capacity.
Here's a pic of the system with the 2405H added. I like the look with the HF driver in the open, as does my wife. My wife was much more concerned (she is a musician) that I might prefer the higher crossover point as she did not like the imbalance resulting from greater midrange presence and lesser bass (perceived or actual not yet fully determined).
Well...I've done lots of reading through the forums, checking of specification sheets and calculations and have some questions before I lose my mind!
1. Is the LE85/2420 a negative polarity transducer (as in the diaphragm moves inwards in response to a positive going signal)? Both the D130 and the 2405H appear to be negative.
2. The LX5 and 3115 appear to be identical networks, however, the LX5 network service bulletin for the LX5 calls for a reversal of the leads to the HF driver, the bulletin for the 3115 does not? Which is correct? I've been using the HF reversed connection to the 3106 network and left the UHF 2405H connected in sync with the LE85. When I used the N1200S network, I did not reverse the HF connections and thus the 2405H was in a different phase relation to the D130 using the two networks (in phase with the N1200 and out of phase with the LX5) Also with the addition of the 3106, the phase of the LE85 gets a 2nd 180 degree filter...yes? no?! Don't worry about it?Help!
3. If a 2nd order crossover results in a 180 degree phase shift, why is it claimed that the HF driver should be connected in reverse to the LF driver to compensate specifically for this phase shift? Both drivers are fed by a 2nd order filter...would they not be therefore be in phase? Or is this due to different phase characteristics in the stopband of the LF and HF sections of the crossover?
4. Using the D130 and the LE85, the driver offset due to the HL91 horn is approximately 8". This would lead to a 180 degree phase difference a little above 800Hz, but does the horn length also affect the phase shift in addition to the driver offset?
5. The LX5/3115 crossover is spec'd at 500Hz, however the network service bulletin shows the response to be down 9dB (LX5) and 7.5dB (3115) at the crossover point and 18dB down at 300Hz, so it's clearly not a simple 12dB/octave rolloff from 500Hz and perhaps was adjusted to compensate for the use of the LE85/2420 down to the 500Hz crossover point with the HL91 horn. The 3dB point looks to be around 1000Hz as the network measures 5dB down at 900Hz for the HF section.
I know this is a lot of questions...but help on any would be appreciated...I'm even wondering if I should try the N1200S with the connections to the 3106 reversed as that midrange emphasis relative to the LX5 could have been a crossover point hump. I'm not just looking to optimize my driver interactions, I love to understand what's going on...so any education will be gratefully received.
Beowulf57
This stuff can drive you crazy.Well...I've done lots of reading through the forums, checking of specification sheets and calculations and have some questions before I lose my mind!
1. Is the LE85/2420 a negative polarity transducer (as in the diaphragm moves inwards in response to a positive going signal)? Both the D130 and the 2405H appear to be negative.
2. The LX5 and 3115 appear to be identical networks, however, the LX5 network service bulletin for the LX5 calls for a reversal of the leads to the HF driver, the bulletin for the 3115 does not? Which is correct? I've been using the HF reversed connection to the 3106 network and left the UHF 2405H connected in sync with the LE85. When I used the N1200S network, I did not reverse the HF connections and thus the 2405H was in a different phase relation to the D130 using the two networks (in phase with the N1200 and out of phase with the LX5) Also with the addition of the 3106, the phase of the LE85 gets a 2nd 180 degree filter...yes? no?! Don't worry about it?
3. If a 2nd order crossover results in a 180 degree phase shift, why is it claimed that the HF driver should be connected in reverse to the LF driver to compensate specifically for this phase shift? Both drivers are fed by a 2nd order filter...would they not be therefore be in phase? Or is this due to different phase characteristics in the stopband of the LF and HF sections of the crossover?
4. Using the D130 and the LE85, the driver offset due to the HL91 horn is approximately 8". This would lead to a 180 degree phase difference a little above 800Hz, but does the horn length also affect the phase shift in addition to the driver offset?
5. The LX5/3115 crossover is spec'd at 500Hz, however the network service bulletin shows the response to be down 9dB (LX5) and 7.5dB (3115) at the crossover point and 18dB down at 300Hz, so it's clearly not a simple 12dB/octave rolloff from 500Hz and perhaps was adjusted to compensate for the use of the LE85/2420 down to the 500Hz crossover point with the HL91 horn. The 3dB point looks to be around 1000Hz as the network measures 5dB down at 900Hz for the HF section.
I know this is a lot of questions...but help on any would be appreciated...I'm even wondering if I should try the N1200S with the connections to the 3106 reversed as that midrange emphasis relative to the LX5 could have been a crossover point hump. I'm not just looking to optimize my driver interactions, I love to understand what's going on...so any education will be gratefully received.
Beowulf57
I used to select a tone on an oscillator at the crossover frequency and using a sound level meter, determine which way was louder. This is usually the correct orientation. I'd do it for the mid relative to the woofer, then the tweeter relative to the mid.
After I got the Behringer, with 61 bands of real-time analysis, I determined that the above method may not be the best. Other portions of the band are also affected and other frequencies may be louder with the other orientation.
Ultimately, I just use the Behringer and determine which orientation gives the overall smoothest response in the room, which is also part of the equation that is typically not considered.
The Behringer cost ~$125 with the mic on the 'Bay and is definately a worthwile investment in sound.
And before I get flamed here, I only use it for measurement and the rest of the time it sits in the closet. It is nowhere to be found in the audio chain.
Hey, Todd,
What model of Behringer did you get? Thanks, and God Bless!
Every Good Wish,
Doc
The only thing that can never be taken away from you, is your honor. Cherish it, in yourself, and in others.
I use an Ultracurve DEQ 2496. Many of us use it on this forum..., probably lots people more than will admit to it.
For my ~$125 'Bay purchase, I also got the ECM8000 microphone.
http://www.enjoythemusic.com/magazin...acurve2496.htm
Thanks for the suggestion Toddalin.This stuff can drive you crazy.
I used to select a tone on an oscillator at the crossover frequency and using a sound level meter, determine which way was louder. This is usually the correct orientation. I'd do it for the mid relative to the woofer, then the tweeter relative to the mid.
After I got the Behringer, with 61 bands of real-time analysis, I determined that the above method may not be the best. Other portions of the band are also affected and other frequencies may be louder with the other orientation.
Ultimately, I just use the Behringer and determine which orientation gives the overall smoothest response in the room, which is also part of the equation that is typically not considered.
The Behringer cost ~$125 with the mic on the 'Bay and is definately a worthwile investment in sound.
And before I get flamed here, I only use it for measurement and the rest of the time it sits in the closet. It is nowhere to be found in the audio chain.Before I start spending more...any other responses to my queries
?
I've read this and your new thread with complete empathy.
Like Todd said, this stuff can drive a guy mad.
The last thing anyone wants is to have some little acoustic god come and clap your room and tell you everything thats wrong with everything you own!
That said, do you think there may be someone in your area with some measurement equipment?
I'm not sure about anything I don't own, CLIO or the like, I have TEF and a TEF unit, or something similar capable of TDS measurements in the hands of someone experienced with it could answer most all of your questions about the absolute polarity of your playback system from the preamp to the speaker components and leave you with graphed measurements of frequency response, magnitude, and phase.
If you set up in advance to be able to swap things around, like having the crossovers out of the cabinets, you could probably get it done in two or three hours, and at least know what you have to work with.
One of the first tools I bought was a Cricket. I was happy with it until I dicsovered that it really struggled with polarity with horns, many measurment systems do I believe due to the changing apparent apacey with changes in frequency. spelling? I have RTA as well, a good tool with limitations.
The TEF opened up a whole new world for me, I can make big system changes and get it close in very short order, electronic crossovers make it easy though.
Best of luck, it isn't easy unless your deaf.
Many thanks 1audiohack...I'll check out the possibilities in my area. With your help and that of the other great folks here, I'm beginning to get my head around the important parameters and how to approach the voicing/phasing issues for my system. Thus,led me closer to
!
If I used a signature, I'd change it to, "It ain't easy unless you're deaf."
I love that line... it is soooo true!
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If a pair of 2312's were available ...does anyone know from experience if this would make an improvement over my HL91's when crossed over at 500Hz?
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