"drop-in" OK for 250ti ?

[SEAWOLF97]

is this a drop-in for classic 250ti ?

and

what would I gain besides "bi-ampability" ???

[Robh3606]

That's biwire not biamp. It might be a TBQ which is not the same crossover as the L250ti with the buss bars. It should work only issue could be the differences in the tweeters network. 044ti vs 035ti

Rob:)

[SEAWOLF97]

Rob ...thanx, I dont have experience with the newer variations and didnt know from whenst it camest... guess I'll pass, since the 044ti is doing just fine and no need to swap it out..:o: It also seems to have fewer profile choices than the "buss bars"

seemed interesting that it is marked "internally wired with Monster cable"

[BMWCCA]

So why does the seller think these crossovers are worth $400? I realize it's a make-an-offer auction but really!
I'd like to have the bus bars on these thought, since they fit the L7.

And, Robh, why aren't they bi-amp? If you remove the buss bar you're separating the low-frequency speaker from the rest of the system, just using the internal crossover. Same as the L7. Pull the bar, run two amps, and you're bi-amping. Bi-wiring is keeping the straps and running two wires, for whatever reason I've never figured out. (Yeah, I read the theory.)

http://ebayitem.com/ Item number:320320445242 (http://ebayitem.com/%20Item%20number:320320445242)

[Robh3606]

just using the internal crossover

That's not really biamping. To truely Biamp you need an active crossover to split the signal. What you are doing is running both amps with fullrange signals to drive the crossovers. When you do this you don't get the advantages of removing the passive network, and reducing the load on the amps.

Rob:)

[BMWCCA]

That's not really biamping. To truely Biamp you need an active crossover to split the signal. What you are doing is running both amps with fullrange signals to drive the crossovers. When you do this you don't get the advantages of removing the passive network, and reducing the load on the amps.OK :o:. But it has to have some advantage over just bi-wire, right? If I use one 200wpc amp for the low end and one 200wpc amp for the upper three drivers, is it absolutely no difference than if I'd just run one 200wpc amp bi-wired into both pairs of terminals? Does the crossover sap all he power that would have gone to the other driver set anyway? Or since there's no actual driver load other than the crossover, does it take some duty away from the amp? Probably off-topic for the thread but I'm curious.

Thanks.

[opimax]

BTW they do not fit w/o modifications. Screw holes do not line up and additional material is needed to fill the hole, they are not as big. It was a real PIA and not worth the effort except the new one were charge coupled. Since they aren't they same I can not really compare them exactly (original TI to TIBQ CC)

Mark

When researching the 250 speaker before purchase It was suggested that the original TI XO was the highest quality or at least that was the way I understood it :)

[Zilch]

Bi-wiring is keeping the straps and running two wires, for whatever reason I've never figured out. (Yeah, I read the theory.)But didn't get it, apparently.

You remove the straps for biwiring, also.

One wire caries the highs, the other the lows.

If you believe in the wire thing, you use the particular type best suited to the appropriate frequency range.... :yes:

[opimax]

If I have the straps off and only hook up 1 side I only hear from the that side (the 14 or the other 3 drivers) so if I do this w/2 amps instead of a single amp wouldn't this be a a true biamp??? Or does biamp have to have active XO to make the definition of biamp?

Does biamping this way do any improvement to sound quality (other than the same as adding a sub letting the drivers not work as hard analogy)or just let me add more power? IE 200 on bottom end 200 on top compared to 400 strapped? :blink::blink:

Thanks

Mark

[BMWCCA]

But didn't get it, apparently.

You remove the straps for biwiring, also.

One wire caries the highs, the other the lows.

If you believe in the wire thing, you use the particular type best suited to the appropriate frequency range.... :yes:

Yeah, I read about skin-effect, etc. But I think I misstated my question using clumsy verbiage. I meant to ask (and edited the post above) if using two 200wpc amps with each channel feeding one pair of speaker inputs has no advantage over bi-wiring with one 200wpc amp? Do the amps see same load running full range into a passive crossover which dead-ends the HF as it does running full-range bi-wired into both HF and LF speaker input pairs?

I also question why bother to remove the straps if you're only bi-wiring with one amp and both pairs of wires are carrying full-range signals? They're bridged at the amp output anyway and so it would seem both are carrying that unwanted treble modulation anyway? If simply bi-wiring cuts down on the intermodulation, then why aren't those same advantages achieved in passive bi-amp mode? Or something like that.

Oh, and thanks for taking the time to beat this into my reluctant brain! ;)

[hjames]

If I have the straps off and only hook up 1 side I only hear from the that side (the 14 or the other 3 drivers) so if I do this w/2 amps instead of a single amp wouldn't this be a a true biamp??? Or does biamp have to have active XO to make the definition of biamp?

Does biamping this way do any improvement to sound quality (other than the same as adding a sub letting the drivers not work as hard analogy)or just let me add more power? IE 200 on bottom end 200 on top compared to 400 strapped? :blink::blink:

Thanks

Mark

Yes, you have to have the active crossover involved to get the benefit of bi-amping.
On my system pulling the jumper means the low side terminals on the speaker go directly to the 2235 woofer - no other components in that path. The woofer amp gets just the low-lows (below 290 on my system) from the active crossover's low-split and that low-only signal goes to just the woofer. That way the woofer doesn't have any significant signal above 300 hz, and the woofer plays just what it does best.

Same thing with the high-split fed to the high side amp and the hi leg of the speaker system - it doesn't have to handle all the energy of bass note ... sound on the high side of the speaker is cleaner.

[BMWCCA]

Yes but . . . bear with me, please! :banghead:

I may have to start a new thread on this subtlety to expect a clear answer. At least from the standpoint of what penetrates my stubborn artistic brain. I was trying to determine the difference between bi-wiring and bi-amping specific the the L7s. Zilch (and the L7 supplement) say toss the jumpers for both. But if you're running both wire pairs off the same one pair of amp outputs, is the only benefit gained in bi-wiring simply the ability to use different types of wire for highs and lows? While they may be split at the speaker, they are certainly joined at the amp so both get the same amp output. The amp probably doesn't much care. It's not like the lows aren't being fed to the "high" wires, too. So what's with the intermodulation theory if the speaker wire "circuits" shares the same bus?

In the L7 bi-amp mode, which uses the L7 crossover's LF-cut circuit to shunt the input and feed only that materal below 180Hz to the 12", does the amp supplying the LF still "waste" power pushing everything above 180? Conversely, does the other amp supplying the HF section with three drivers "waste" power pushing signal below 180Hz to the HF section? Or is the amp power-draw based on what those speaker "motors" ask for on demand in electromotive power to convert it to kinetic energy? If I turn up my amp but connect no speakers, is the amp seeing a load? Infinity? When in bi-amp mode on the L7, are the components of the passive crossover eating up that power that would go to the unused frequency range and making the amp see a load that perhaps dissipated in heat energy, like an incandescent-lamp dimmer? Certainly an amp is producing whatever frequencies are being sent to it by the source, but if a tree falls in the woods . . .?

Obviously an active crossover is dealing with low line-level signal and a passive is dealing with high speaker-level signal. But does a 200wpc amp see the same load when bi-amping the L7 only below 180Hz with the straps off as it does when it runs direct through the whole crossover with the straps in place? It seems like that's what's being said here.

I'm not an engineer but I can draw a line connecting two points. It would seem the jumper wire inside the L7 crossover by-passes the LF crossover-point completely for true bi-amping using an active crossover (though that's not clear to me in the schematic). But is there no benefit to using the passive crossover in bi-amp mode with two amps beyond whatever gains are enjoyed in bi-wire mode using one?

[SEAWOLF97]

Oh no, once again I agree with BFDH,,, so then, what IS the reason to "bi-wire" ??

__________________________________________________ ______________

COMPLETELY DIFF SUBJECT (since this thread has morphed around, a bit)

did you know there is an "audio wiki" ??

http://audiophilewiki.org/

and no, the thread subject isnt in there ....:(

[hjames]

Okay - I checked the schematic for the L7 Speaker
http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L7%20ts.pdf

It looks like pulling one jumper leaves a portion of the crossover network between the Lo-F terminals and the woofer. If you pull the second jumper,
the only thing left in the LOF circuit is the woofer and L1 inductor.

In BiWire Mode I'm guessing this functions as a Low Pass network and effectively filters high frequency signal from reaching the woofer when used in that mode.





Yes but . . . bear with me, please! :banghead:


In the L7 bi-amp mode, which uses the L7 crossover's LF-cut circuit to shunt the input and feed only that materal below 180Hz to the 12", does the amp supplying the LF still "waste" power pushing everything above 180? Conversely, does the other amp supplying the HF section with three drivers "waste" power pushing signal below 180Hz to the HF section? Or is the amp power-draw based on what those speaker "motors" ask for on demand in electromotive power to convert it to kinetic energy? If I turn up my amp but connect no speakers, is the amp seeing a load? Infinity? When in bi-amp mode on the L7, are the components of the passive crossover eating up that power that would go to the unused frequency range and making the amp see a load that perhaps dissipated in heat energy, like an incandescent-lamp dimmer? Certainly an amp is producing whatever frequencies are being sent to it by the source, but if a tree falls in the woods . . .?

Obviously an active crossover is dealing with low line-level signal and a passive is dealing with high speaker-level signal. But does a 200wpc amp see the same load when bi-amping the L7 only below 180Hz with the straps off as it does when it runs direct through the whole crossover with the straps in place? It seems like that's what's being said here.

I'm not an engineer but I can draw a line connecting two points. It would seem the jumper wire inside the L7 crossover by-passes the LF crossover-point completely for true bi-amping using an active crossover (though that's not clear to me in the schematic). But is there no benefit to using the passive crossover in bi-amp mode with two amps beyond whatever gains are enjoyed in bi-wire mode using one?

[BMWCCA]

Okay - I checked the schematic for the L7 Speaker
http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L7%20ts.pdf

It looks like pulling one jumper leaves a portion of the crossover network between the Lo-F terminals and the woofer. If you pull the second jumper,
the only thing left in the LOF circuit is the woofer and L1 inductor.

In BiWire Mode I'm guessing this functions as a Low Pass network and effectively filters high frequency signal from reaching the woofer when used in that mode.
According to the L7 supplement, neither bi-wiring or bi-amping require removing the internal jumper, but only the external ones at the input terminals. The internal blue wire is (according to the L7 designer) supposed to be moved when used with an active crossover: http://www.audioheritage.org/vbulletin/showpost.php?p=178680&postcount=152

[hjames]

According to the L7 supplement, neither bi-wiring or bi-amping require removing the internal jumper, but only the external ones at the input terminals. The internal blue wire is (according to the L7 designer) supposed to be moved when used with an active crossover: http://www.audioheritage.org/vbulletin/showpost.php?p=178680&postcount=152

Well - how would you be biamping it without an external active crossover?

that would just be biwiring ...

heck, no WONDER its confusing!!

I guess it all depends on what the definition of is is ...!

[BMWCCA]

Well - how would you be biamping it without an external active crossover?

that would just be biwiring ...

heck, no WONDER its confusing!!

I guess it all depends on what the definition of is is ...!

The L7 has two pairs of input terminals joined via strapping bars, just like the crossover in the first post in this thread. (That's pretty much why we're stuck discussing this in this thread.) The L7 crossover is essentially two separate crossovers, each with its own part number. When you remove the external straps you separate the 12" from the other three drivers but you keep the high-cut so when you wire in two amps the LE120H-1 doesn't go full-range even without an active crossover. The question is why doesn't this gain you some power advantage if you use two amps and the suggestion was that you wouldn't because of the passive crossover. That's what's confusing. The L7 manual draws a distinction between bi-wiring with one amp per speaker and bi-wiring with two-amps per speaker. Perhaps the confusion is that I've been referring to the latter arrangement as bi-amping when they still call it bi-wiring. That might explain why all the intelligent members here bailed a while back on any attempt to beat some sense into me. :D Here's a sample of JBL's confusing language.

The manual says:

Drawings L-G and L-H show two bi-amplifìcation options: dual stereo amplifier and four-amplifier modes.

Bi-wiring also allows you the option of using separate stereo power amplifiers for left and right L7 loudspeakers or even four mono power amplifiers. Using two stereo amplifiers (drawing L-D) can not only add sonic improvements but upgrade convenience as well. From a sound standpoint dual amplifiers reduce intermodulation between left and right channels, since a complete set of input and power supply circuits are devoted to each speaker. Dual amps also provide an easy power upgrade path: you can start out w¡th one stereo amplifier; then add a second one later to quadruple power reserves. Three or four individual amplifiers provide even more possibilities, since you can use different brands and types of amps for HF and LF power. Many serious listeners prefer the midrange and treble sound quality produced by tube amplifiers. However, many tube designs do not provide as "tight" a bass sound as solid state models and often produce less power3. Bi-wiring with separate bass and treble amplifiers allows use of both tube and solid state designs, where each is most desirable.

Whether you are using two or four amplifiers, it is important to use the same brand and power rating to power like connections
on the L7's. ln fact, since the cross-over point for the L7's HF/LF connections is l50Hz (the specs say 180—pm), using amplifiers of the same power for both woofer and midbass/midrange/treble connections is recommended.Got that?? I'm assuming this is similar to the way the 250Ti crossover works, above, just to show that I'm sort of on topic!

Here's a link to the L7 supplement which talks about true bi-amping, as well: http://manuals.harman.com/JBL/HOM/Owner%27s%20Manual/L7%20om%20Supplement.pdf

[opimax]

Phil I am with you on what make sense to me about bi amping, 2 amps per speaker seem to be bi amped and again to me Bi amping w/active XO would be bi amping w/active XO.:applaud:

Now that I understand the definition

Please correct me if I am wrong

1) bi wiring w/2 amps(all the same make and model) per speaker will yield more power to the speaker (thus more DBs). 200 + 200
2) would this 200w + 200w = a single 400w I wouldn't think so but???
3)The amps will each see full range because of the XO and still will filter out the top end on the woofer and the lower end of "top half" , IE the amps don't get told to only produce part of the sound spectrum but the full range and the rest(highs from the low end and lows from the high end) are dissapated to heat (i guess??)

If the amps are producing full range what are the benefits of doing this?

Mark

[Robh3606]

You need to look at the Tech Sheet. It's really odd. There is a moveble 4" Blue jumper in the woofer section that if you move it takes out the lowpass filter. That said the bandpass filter on the 8" midbass driver looks like it has no such provisions for the highpass portion??? So if you moved the strap you could "biamp" the woofer but not the Midwoofer without extensive modifications. Or at least taking the 90uf out of the picture. Strange????

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L7%20ts.pdf

Rob:)

[BMWCCA]

That might explain why all the intelligent members here bailed a while back on any attempt to beat some sense into me. :D
That was not meant to imply that either Opi or Heather lack intelligence. They'll stay around to beat some sense into me because they know I'm nutz. I can't help but think the EEs here are just laughing at the basic theories we are ignoring so cavalierly out of pure ignorance.

That's OK. As Heather said, "The joy of the pie is in the eating .." I've got a pair of D150A-IIs, a pair of PS-200s, a pair of PS-400s, a pair of Pro-Control-Fours, a pair of DX-4200s . . . and two pairs of L7s. If I can't make a valid comparison of the wiring schemes with that pile of crap, I'd be pretty worthless. Yeah, I know . . . :yes:

[hjames]

That's OK. As Heather said, "The joy of the pie is in the eating .." . :yes:

Unless its hagis! :blink:

[BMWCCA]

It's really odd. There is a moveble 4" Blue jumper in the woofer section that if you move it takes out the lowpass filter.
Yep. Odd it is. But this is the best info we have to go on, including a photo of the blue jumper wire:

The internal blue wire is (according to the L7 designer) supposed to be moved when used with an active crossover: http://www.audioheritage.org/vbullet...&postcount=152 (http://www.audioheritage.org/vbulletin/showthread.php?p=178680#post178680)