timbley

---------------- On 4/20/2005 7:20:28 PM Dylanl wrote: Thats interesting. I have always wanted to try true bi-amping with an active crossover. Then eliminate the crossovers all together on my Khorns. From what I have found the process is expensive. You also need a good equalizer right? I like the thought of running the bass with SS and horns with tubes. ---------------- I first got interested in this idea reading about the DEQX, which is said to be a fantastic unit, but pretty darned expensive for my budget at 3 grand. I did a lot of reading about the Behringer DEQ and DCX units before I decided to give them a try. One guy who had used both said you got most of the benifit with the Behringer stuff that the DEQX could provide, he threw up a number like 70%. That was good enough for me. You can get a Behringer DEQ2496 equalizer, the calibrated microphone to go with it, and the DCX2496 crossover for about $600.00 total. Throw in a Panasonic or JVC digital receiver and you've got decent amp channels and coordinated volume control for under $1000.00!

Interesting post. I was just using the Panasonic SA-XR50 up until recently. Had the 25 before that. They're both great sounding units. I think the 50's just a little smoother and more refined. There's a new XR55 due out soon. The JVC F10 is another amazing sounding chip amp cheapy, which I'm using now. I'm so impressed with the sound of these little chip units, it's hard to even consider something more expensive. And, they've got 5 available amplifier channels for bi-amping!

That is high class. Some day I'm going to have to try the full horn route.

---------------- On 4/20/2005 9:24:02 AM Maron Horonzak wrote: After doing some calculations....Thats not mutch of a Track-Trix flair design, But closer to a squaired conicle design. ---------------- It does look like a straight squared conical flair for most of it's surface.

---------------- On 4/20/2005 2:29:38 PM Dylanl wrote: Timbley, I noticed your saying at the bottom of the thread Tri-amp and loving it. Can you explain to me how you are doing this with the RF7? ---------------- I have my system listed up to date under my info if you want more detailed info. I'm using a Behringer DCX active crossover with two JVC RX-f10 receivers. Each receiver uses 3 of it's 5 available amplifiers to power the tweeter and each mid-woofer. The DCX crossover has 3 analog outputs per stereo channel. I use one of them for the tweeter, and the other two for the woofers. The two woofer outputs are the same, so the woofers are moving together like usual, but they each have their own dedicated amplifier. I had to run one speaker cable in through the lower port to do this. The passive crossovers have been removed. I've been waiting to talk more about this set up. I've been working on it for a while, and I think I've finally reached a point where I'm very close to optimized with the EQ and crossover settings I want to listen for a good while and let my ears settle in before I rave it up too much. So far, I absolutely love it.

---------------- On 4/20/2005 9:28:22 AM jacksonbart wrote: How does it sound with the putty applied? ---------------- Mostly the same, but just a little more open. It's taken a sligth glare off that was affecting woodwinds particularly, and making some other instruments sound slightly hollow and wooden. That's been pretty much cleared up now. I'm not noticing it. My theory was that the 10" midwoofers might have been exciting the horn from inside the cabinet, making it amplify their frequencies a little, with the weird effect of trying to push a low frequency through too small of a horn. I've noticed a similar sound if I try to push the horn down to too low a crossover frequency. It gets that wooden "tock" effect with pink noise around 1.4kHz.

I haven't seen any other posts about damping the RF-7 tweeter, so I thought I'd share this. I've been noticing a slight coloration from the RF-7s that I'd best describe as a "tock", like a tick tock from a wooden cuckoo clock. If you tap the horn with your fingernail, you'll hear what I'm talking about. This tap test led me to try damping the horn I used removable contact putty and a bunch of yarn. I didn't realize until I was done that there was so much talk on these forums about the damping of horns, or I'd have known to buy rope caulk. Putty and yarn is effective. I don't know if the yarn was really necessary, but in any case I'm not hearing the "tock" effect any more, which makes me very happy. Here's a couple pictures. I forgot to take one with the yarn. It looks like it's wearing a nice thick sweater.

I used an SA-XR50 with my RF-7s until just recently. It's an impressively clean, detailed sounding receiver, especially when used through it's digital inputs. For two channel listening with my RF-7s, it was a little challenged in the bass department. I think it would do better with a little less demanding speaker, and better still with a powered subwoofer helping out. It's bass management only allows crossover points of 100, 150, or 200Hz though. I don't know anything about the Synergy's impedance curve, but I imagine it's easier on amps than the RF7 is. I actually had two of the SA-XR50s at one point, as well as an SA-XR25. I sold the extra 50 and the 25, and both buyers have reported back to me that they are very pleased. Another inexpensive receiver to consider is the JVC RX-F10. It has a warmer sound, and pushes out the lower frequencies with apparent ease on my RF-7s. It's also said to have better analog inputs. The Panasonic has to convert the analog inputs to digital before it can perform pre-amp and amplification functions, while the JVC doesn't since it uses analog control signals for it's amps. If you're going to be primarily supplying a digital signal out from your DVD/CD player or computer's optical or coaxial digital outputs, the general consensus is that the SA-XR50 is hard to beat. If you're primarily supplying analog signals, then the JVC is probably better. One last thing: neither the JVC or Panasonic have a phono input. So if you listen to records, you'll need an external phono stage.

---------------- On 4/15/2005 10:50:56 PM garymd wrote: I don't really know why it is but sometimes my system just sounds better to me than other times. ---------------- I'm convinced that humidity, temperature, and pressure have something to do with it too. I used to play the double bass. I noticed some nights it would be the most mellow sounding instrument you can imagine. Other nights, it'd have a harsh edge to the sound, a sort of raspy bass. No technique or change of rosin could help. Everybody else's bass would have the same problem on those nights. It was just one of those nights. Another thing that convinces me of this is that when my system starts to have a certain rough edge it, I notice people's voices in my house have a similar rough edge.

I've been waiting for them to do this. Panasonic bi-amps some of it's mini stereos, although I don't know if they're actually using an active crossover or not. It would be quite inexpensive these days.

---------------- On 4/12/2005 5:10:43 PM Fish wrote: JVC ? No offence but I would not hook a jvc to my rf7's,well maybe a very old one for a short time.The 7s are picky w/very good gear.---------------- I can see your point. The JVC brand name doesn't conjure much of an audiophile aura. But the RX-F10 is not your typical sounding JVC receiver. The Sonic Impact, Teac, and other digital amps are getting a lot of attention from audiophiles lately. This little JVC "digital" is also getting glowing reviews, especially for it's ability to drive difficult speakers. OTH, the mid-level receivers in the 500 to 1000 dollar range that use more traditional amplification don't seem to be generating much excitement. I don't see the point in forking out the extra cash for something that's temporary, and possibly not any better. I am currently using this little JVC receiver with my RF-7. It's smooth, detailed, warm, and extends down to lower bass tones than I previously thought the RF-7's could produce in my listening room. I haven't tried any really high end amps, so I'm not saying the JVC could compete head to head with the good stuff (although some folks do say that.) As for my limited experience, I've had a Parasound high current amp, a Sherwood tube integrated, a Creek integrated, a couple of Panasonic digital amps, a cheap RCA receiver, and a cheap Sony receiver on my RF-7s. Previous to the JVC, they ranked from best to worst as follows 1. Panasonic 2. Sherwood tube 3. Creek 4. Parasound. The RCA and Sony tied for a very distant 5th. They were hopeless. The Parasound was pretty strident and hashy, but at least it wasn't completely flat and lifeless. The Sherwood tube was full and warm sounding, but had vague imaging and loose bass. It was quite pleasant, but when I tried the Panasonic, I knew the Sherwood's time was over. The Pansonic really blew my mind, with splendid detail and clarity. Unfortunately, it had no real guts with the RF-7s, making the 7s sound a little brighter and lighter than they should. The bass was there, even annoying at times because of room modes, but it didn't fill out all the frequencies enough, or go down very far. I even tried passive biamping with a couple of Panasonics, but it didn't help. The JVC gives up little if anything in the way of detail and clarity to the Panasonic, and it's got some impressive guts for such a small package.

I must suggest the JVC RX-F10. jr.com sells them delivered for$229.00. I found two of them on close out at my local Video Only for $159.00 each. These little receivers use JVC's "digital hybrid feedback" amplifiers, which are well suited to handle the RF-7's impedance dips. They push out smooth, clean bass down as low as the 7 will go. I think you'll be happy with one of these, at least to hold you over until you get some killer seperates.

The manual says the analog XLR inputs and outputs are +12 or +22dbu, while the 1/4" are +12 only. The outputs are also +12 or +22 XLR. You can use an XLR to RCA adapter cable, and the unit will automatically detect that, adding 6db gain on the output, which isn't necessarily what you want. If you adjust your EQ to reduce peaks instead of boosting lows, you will effectively attenuate the output a bit. Also, there's a digital offset, so it's not too hard to get a reasonable output that will match your amp. The controls go from +15 to -15db. The lowest adjustable frequency is 20Hz. From what others have said, the analog input on the DEQ isn't great, but the analog out not too shabby. This is a somewhat complicated thing to install. Some people use it for it's rta functions to help get their room adjusted optimally, but then don't leave it in the signal path for regular listening.

You can get a DEQ2496 for about $300.00. I bought mine at the local Guitar Center. Samedaymusic.com also has them, and a number of other music supply sites. I'm using it with my RF-7s, which are currently biamped using the JVC RXF10 and a Behringer DCX as the active crossover. I'm not using the JVC's digital equalizer or any of it's digital processing features, I just noticed it had an EQ function with a few bands. Here's a link to a sight that sells autoformers: http://www.zeroimpedance.com/zero2x.html Anybody have any experience with using autoformers on speakers?

Well, I think highly of my Behringer DEQ2496. It's digital, but has analog inputs and outputs, so you could use it between the pre-amp and amp. It also has digital optical inputs and outputs, so you could use it between your CD transport and a high end DAC. It's really nice in that it has an RTA with microphone input. You can get the microphone for it for about 40 bucks. This would give you an idea of what the frequency response of the speakers and your room looks like, and how EQ settings effect the sound, and perhaps help you place the speakers and use room treatments more effectively. It'll give you a lot of EQ power, with 10 fully adjustable parametric bands per channel, and a 31 band graphic EQ on top of that. I think it has memory for 64 settings, which you can name, so you can compare different EQ settinngs easily. If you want to start simpler for experimenting, I have an old BiAmp brand 10 band / channel graphic EQ that my friend wants me to sell for him on Ebay. That would be quite inexpensive I'm sure. I've never listened to it, so I can't comment on it's sound quality. But at least you could put some EQ in. One other option, the JVC F10 reciever I'm playing with now has a simple digital EQ circuit in it. I think it only has 4 bands, but still it's better than just tone controls. This little receiver is noted to drive tough impedance loads well, and I think it does flesh out the bass in the RF7 pretty well. I read a little about the Forte amps, and someone on Audioasylum was suggesting that they didn't do well with low impedance. He was using an autoformer to increase the apparent impedance of the speaker to the amplifier, and said it made remarkable improvements in bass clarity and the overall quality of the sound. Interesting.

---------------- your amps cannot handle the impedance drop in the RF-7's at the lower frequencies... as has been pointed out in more than a few threads, the RF-7's impedance drops below 3 ohms in several areas in the bass frequencies.... it is pretty obvious that your amplifier(s) cannot handle this impedance drop get yourself a quality amp that has some guts to drive low impedance loads and you will get a ton of bass from the RF-7's for music applications (two channel) you should never need to use a sub with these speakers ---------------- You might want to look into this notion also. An amp can make a big difference, despite it's power rating. I just picked up another cheap digital receiver last night, a JVC F10 digital hybrid feedback design. TheChairGuy on audiocircle has been raving about it, claiming it sounds great through it's analog inputs and can handle difficult impedance loads. For 159 bucks, I figured it was worth a try. Sure enough, this little wonder fleshes out bass much better. It's rated at 100watts, just like my Panasonic was, but it digs way deeper. Playing pink noise and looking at the EQ, I can see that the bass doesn't look elevated or boosted. But the difference is obvious whenever some really deep bass gets going. It's really solid and deep with this amp. I thought a heavy truck was going outside at one point because I felt a powerful low frequency rumble. It was my RF-7s! The little JVC is really a sweet sounding thing. It's warmer and richer than the Panasonic. I think it's a good match for the Behringer crossover's analog outputs, and the RF-7s impedance issues. I know it's hard to believe that something with JVC on it could make good sound, but I challenge any of you to try the F10 with your RF7s, and tell me it doesn't sound smooth and sweet, and dig deep in the bass.

Hmm, I never had a problem with the RF-7s lacking bass. And that was running them with a little Panasonic SA-XR50! My girlfriend would ask me to turn down the thundering bass regularly. I now have an EQ, and the bass controls are notched down at a few room modes in the bass. Definitely no gain is needed. These speakers actually have good, flat response from about 17K to 35hz or so. The horn may be more directional than the 10's so it beams to your listening position better, making it seem too loud. Room acoustics are probably the primary culprit here. If you look at Klipsch's crossover circuit, you can see there's an attenuation circuit that cuts the horn way down at (I'm guessing) 9K. The speaker's impedance falls to 2.8 ohms around 9K, and that's probably because of this bypass circuit, which only presents a 1 ohm and a 2 ohm resistor as a load in parallel with the tweeter at that frequency. Messing with those resistor values could change everything. If you go with active crossovers, you'll need some kind of EQ for the tweeter to bring it down toward the middle of it's range, and boost it a bit toward 20K if you want your highs extended. My most aggressive EQ is on the tweeter, with about a 5db cut at 4.8k, and a 10db gain at 17k. I also have a 10 ohm resistor in series with the tweeter to bring it down a few db, although that could be done by controlling the gain output on the DCX crossover. I just happened to have those resistors, and they bring the tweeter pretty close to even with the woofers overall. Furthermore, after adjusting my speakers for flat response in the room, I've applied a gentle treble roll off using the graphic EQ function of the DEQ2496. I like doing it that way because I find the desired treble roll off is the main thing that differs between different recordings, and the graphic EQ makes it easy to change this without messing up everything else.

---------------- On 4/5/2005 1:01:57 PM Spkrdctr wrote: Hey guys, what are you doing for "passive Bi-amping?" Thanks for the info! ---------------- Hey Spkrdctr, I'm not sure I understand your question, but when I was "passive bi-amping" I was running two SA-XR50 recievers with cable splitters from the various devices feeding each receiver. The remote control kept the volumes synched. I ran one reciever's speaker cables to the HF terminals and the other to the LF terminals on the RF-7s.

That may all be true, but I coudn't hear it when I tried.

You already are doing this, or you are going to? I'm curious to find out if you think it makes an improvement from just using one amp. Those amps should be able to run the RF-7 handily without bi-amping, so I'll be a little suprised if you find a big improvement. But you never know until you try. I tried passive bi-amping with 2 Panasonic SA-XR50 receivers, figuring they'd benifit from sharing the current load a little. I thought I heard good things from time to time, but it always ended up being because of something other than the bi-amping, such as the tone controls being changed without me realizing it. In the end, that configuration really didn't amount to much. A single SA-XR50 running the whole speaker really sounded just as good, maybe even a little better. Right now I'm experimenting with a Behringer DCX2496 active crossover, bypassing the speaker's passive network. So far I'm really impressed with the sound. The bass is tighter, the mids sound clearer, the highs more extended and less edgy, and I get a much more convincing stereo image, especially with some careful attention to the EQ. Almost all my records and CDs sound better. A few of them don't for some reason, mostly electonic music. Kraftwerk's "Tour de France" sounds too smooth and laid back to me now. "Neu!" had sizzling energy and slam before, which I liked. It sounds like a poor recording now, with murky bass and slightly muffled highs. I'm at a loss to explain that when so many other recordings sound so much better. I'm going to put the passive crossovers back in at some point and listen to them again just to make sure I'm not delusional.

I think very interesting times are ahead, possibly within my lifetime. We are just like every other organism on the planet. When we come across a stockpiled natural rescource that has tremendous potential, we build on it until we use it up. At that point there is a massive overshoot from the normal rate at which the environment can supply our needs, and so we crash back down. Our latest progress seems long in our eyes, but 150 years really ain't much in the light of history, or even 2000 years in the light of natural history. I think this is an important mechanism of evolution. Natural selection occurs best from large population bases under very trying circumstances that allow only some to survive. We instinctively will make all the decisions neccessary to eventually bring us to that point. Free markets work perfectly that way. It's all about growth, growth, growth, right? Well, do you really think growth is going to go on for ever? That's just not possible, not for any system that uses matter to build itself. We will fall back, and build up, over, and over again. Me, I'm not worried about it. It's all good. It's just better if you can live during an upswing period, and I'm glad I do!

Thanks for all of your responses guys. I'm learning about a lot of stuff. I must admit, I know little about crossovers. I've heard of a Zobel before, but don't know what it is. I understand caps impede low frequencies and coils high, resistors everything. I'm starting to think that an emphasis in a certain frequency range can make the sound clearer. When EQ is applied to smooth out the response, the apparent clarity is reduced at first listen. It sounds more confused because you can hear more, not because the phase is messed with. That's what Ethan Whiner says. Looking at the RF-7 response with active crossovers, it really rolls off quite a bit in the bass and treble. The passive crossover accomplish a lot of EQ.

I experimented a little with shifting the phase on the tweeter using the Behringer. I could hear a little happen when listening to white noise, but very little if nothing when listening to music. I think the cancellation effects are minamal because the crossover slopes I'm using are pretty steep. But, that test was when I was using lots of EQ. Last night I tried listening with no EQ, just a pair of 10ohm resistors in series with the tweeters to bring them down to about the same level as the midrange, and hopefully flatten out their response a bit, (although that didn't appear to happen much looking at the RTA, they still roll off fairly sharply above about 7K.) The un-EQ'd balance was suprisingly listenable despite the response not looking all that flat. I moved the crossover point down a bit to a point with a smooth looking transition. The sound was very, very clear and non fatiguing, with a prominent midrange, giving vocals a lot of power. I listened until 1:00a.m., and wanted to crank it way up. Didn't want to go to bed. While listening, I tried to apply a litte EQ here and there, and I got the distinct impression that the clarity was reduced each time, somehow the sound had become a little confused. Switching the polarity on the tweeter wasn't good. Hmm, I'll have to listen some more.

Hey, all I can say is the Behringer gear is doing a nice job in my system, and it's inexpensive. The DCX certainly sounds better than my passive crossovers did. The DEQ made my speakers sound better when running my passive crossovers than when I bypassed it, night and day in my opinion. It may be a cheap knock off of something, but it does a decent job. Now that I'm biamping, I'm finding I don't need to EQ. I like the way the speaker sound "raw," although I have added 10ohm resistors in series with the tweeters to bring them in line with the woofers. Edit: While highly listenable without EQ, I still like some EQ after all. I may step out for more expensive gear some day. DEQX looks intriguing. Behringer is what I can afford right now. It's made it clear to me that I definitely want to continue to use active crossovers.

Al K, I was wondering about this because it was explained to me that my digital crossover and EQ emulate analog designes, with all of their phase shift issues included. More expensive digital crossovers and EQs are "phase coherent." Some people were making a big deal out of this, and I just started to wonder what I might be missing out on.