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Steve Gonzales
04-11-2006, 12:52 AM
While I run my system in full triamp mode, I've often wondered what the effects of an electronic crossover being used in a biamp configuration are?. Here is an example: JBL 4343 in biamp configuration: Low pass into an amplifier, then into the LF input terminals of the 4343's crossover, then the HP is routed to an amplifier and then hooked to the top end terminals which then divides the signal passively. So what type of interaction between the electronic crossover and the passive is taking place?. If the electronic crossover has a 12db/oct slope and the passive circuit has a 12db/oct slope, what happens to the phase?. I have assumed, that since they add, a 24db/oct slope will be the outcome and remain in phase with the LP/LF section, assuming that the LP was an even order too?. What are the other effects going on here?. What can a pure passive crossover of high quality do better than a good electronic crossover and vice-versa? Another question I've wondered about is if a stock passive crossover can be easily modified to suit a completely different driver. Here is an example: An N220 passive is engineered to work with an LE5-9 midrange. Can just the midrange section of the network be modified to work with an LE85/H92 combo without touching the HP/LP filter sections in the network? It seems to me that it would effect the whole thing. Thank you for the information, Steve G.

Ian Mackenzie
04-11-2006, 01:53 AM
information overload.

in the case of biamping a JBL monitor, the woofer low pass passive filter is usual completely bypassed and the high pass filter to the mid/horn etc is also bypaased so you only get the slope of the active filter (the 4435/35 is the exeception where the active and passive high pass filters do combine

As a rule electronic active filter do intrude on the tonality of loudspeakers for hifi use with soe rare exceptions.

To be continued:

Steve Gonzales
04-11-2006, 02:03 AM
It seems to me that if a 4343's passive section was completely bypassed, the midbass,midrange and UHF wouldn't get filtered. Say you were to use an M552 and cross over at 250hz. I believe that the passive is still engaged because how else would the 10" midbass, 2307/2420 and 2405 "self filter" with respect to each other?.

Ian Mackenzie
04-11-2006, 04:55 AM
Sorry but only only had one minute to reply.

I don't have time to upload a schematic but what happens is the mid cone high pass passive filter elements are bypassed so there is no series capacitors or inductor shunted across the signal. Nor does the woofer have a series inductor or a capacitor shunted across the signal. Normally the horn and tweeter continue to use their passive filter elements. In the case of the 3143 network as I recall the horn and and uhf signals were via the mid filter to provide better protection from amplifier transients.

Getting back to your question.

In th case of JBL engineered systems, the filters are tailored especially for the system at hand so either active or passive will provide nearly identifcal acoustic response.

Note this is seldom the case when a diy person attempts to bi amp an existing passive crossover..

The prime benefit is better performance from the woofer in most home brew active systems. In professional applications like monitoring it results in greater dynamic range and reduces power loss in the use of passive networks.

Active crossovers however do not necessarily mean a handshake for improved fidelity for home listening. It depends on the standard of your other equipment and that of your speakers.

Sorry I do not have time to consider your other questions and i am not sure how you have your system currently arranged. This would require a complete re design of the crossover network and is best left to an experienced / qualified person with test equipment such as Clio / Leap

Robh3606
04-11-2006, 05:54 AM
Hello Steve

To keep it simple when you biamp a 4343/44 you remove the Low pass filter on the woofer and 1/2 of the bandpass filter on the 2121/22. You still have the other half of the bandpass filter in line for the 2121/2 to provide a smooth transition to the compression driver as well as the rest of the crossover.


Rob:)

Steve Gonzales
04-13-2006, 12:06 AM
Kinda already knew that stuff, gents, thanks anyway. I want to know what's going on between the passive and electronic, is there something special about the blending of them that gives the speaker it's tonal quality or a compromise for the obvious reasons?. I just used the 4343 as an example. What I should have asked was: is it that difficult to achieve the same tonal quality in a 4 way with an all electronic crossover? I've had great success with my triamped system, so it doesn't seem a stretch to do it with a four way, I need to hear from someone that has heard both, picked one, and why. There is not a bi-amp capable passive crossover in the JBL inventory that is exactly what I need. I've considered having some built but don't want to go through that much trouble if I can expect the same performance from a quality electronic. Is there something particularly better about the way a passive sounds vs. an electronic of equal quality?

Mr. Widget
04-13-2006, 01:26 AM
What I should have asked was: is it that difficult to achieve the same tonal quality in a 4 way with an all electronic crossover?That is a very broad question.

Let me try to explain. If the passive network has asymmetrical slopes, overlapping slopes, slopes that are not textbook for any other reason, additional filters to tame resonance, compensate for HF fall off or any other unusual aspects you may not be able to duplicate it with just any crossover. There are some that can be tailored to match most or all of these conditions, but if you don't FULLY understand what the passive network you are trying to emulate is doing, you will never really duplicate it's sound.



Is there something particularly better about the way a passive sounds vs. an electronic of equal quality?Not inherently, but... See above....

That said, I've posted this before but bear with me. Adding an active crossover is the same as adding a second preamp. If you have a good system (one that doesn't use ANY LSI chip based receiver, processor, or integrated) you should try to get one of the very few crossovers that are as good as your preamp. All of the affordable semi-pro and pro models that we are familiar with don't cut it. Some are better than others, but they all add a sonic signature that ideally wouldn't be there. Forget the subtlety of changing wires... we are talking sonic signature.

An example of whether or not it is possible to match the sound of an active and passive network. I use my active as a tool in designing my passive filters. I can quickly compare a 1st, 2nd, 3rd order etc. at any frequency with my digital active and when I hear what I like I build the passive... I build the passive for the actual impedance not the label and it sounds and measures surprisingly similar to the electronic one I liked.


Widget

Ian Mackenzie
04-13-2006, 01:44 AM
Steve,

In my view the most improvement comes from biamping.

To tri or quad amp addsa lot of complexity and issues of S/n ratio can arise with horns unless great care is taken.

For example you might have a nice SS amp for your woofers and a nice sweet SE Triode for your horns. Provided the active crossover is up to the task you will reap the rewards. In some cases where your Valve amp has a high input impediance say 1-2 megohms a simple high level passive RC network b/n the pre amp and the power amp is all that is required with a buffered low pass filter for the low end.

As Widget say, particularly if you are dealing with unknwn drivers some experiementation of slopes and crossover points is required for the best blend just asa designer would tailor a passive network. 9/10 times most drivers are not plug and play!

Ian

Robh3606
04-13-2006, 06:06 AM
There is tailoring in the passive neworks that an M552 or M553 cannot duplicate. One of the more flexible digital loudspeaker management systems can do tailoring like a passive network. I have an active 4 way and my biamped 4344's both sound great, well to me at least:). But like Widget and Ian say drivers are not plug and play. You may get a peak hear or there depending on where your crossover points are and what the individual driver responses are. With a typical active you don't have to worry about attenuation and you have flexabillity of moving the crossover point. In a simple analog 24db like the ones we are using you can't do different slopes or assymetrical ones. Your stuck with only those 2 variables. With a pasive network you have no limitations. As long as you recognize what you can and cannot do you should be fine using common sense your ears and some basic measurement tools.

Rob:)

Steve Gonzales
04-13-2006, 01:55 PM
Thank you all, for your opinions. Widget, what do you mean when you say that one of the reasons you use a passive is because of the impedence?. Is it not better to filter the signal, i.e, have the amp deal with the driver's reactive load than an LCR network?. Also, what experience do any of you have with electronic crossovers that manipulate the signal in the digital domain? I'm considering a JBL DSC 260 or 280, they have the ablilty to equalize and I believe time correction too. I realize that my M553 is not the end-all. What it has allowed me to do is get my feet wet and experience the ease and flexiblity an active crossover can offer. When I start upgrading things, I like to be informed about the choices and the pros and cons of those choices. Your answers will help, thank you.

Mr. Widget
04-13-2006, 02:19 PM
Widget, what do you mean when you say that one of the reasons you use a passive is because of the impedence?.I didn't say that! I said pay attention to what the impedance really is.

I'd avoid those two older JBL digital units... digital is changing fast... anything older than the last year or two isn't very good... yeah, that is a generalization, but reasonably true.


Widget

Steve Gonzales
04-13-2006, 02:25 PM
What is your active crossover of choice?

boputnam
04-13-2006, 02:50 PM
What is your active crossover of choice?Analogue, or digital...?

Steve Gonzales
04-13-2006, 02:59 PM
Since I'm gathering info for an upgrade, I'd love to have some recommendations. Maybe your take on what the best overall, as far as type, is.

BTW Bo, I've often wondered how the short conical 2307 w/2420 is so good in the 4345.

Mr. Widget
04-13-2006, 04:58 PM
BTW Bo, I've often wondered how the short conical 2307 w/2420 is so good in the 4345.Since Bo answered a question I thought was directed at me, I'll butt in and give an answer posed to him. :D

The 4345 uses the 2421 not 2420... that helps and the 1200Hz crossover also helps. In Bo's case he further helps out his 4345s with careful EQ.

As for the crossover question.

I really like the DEQX PDC 2.6P I am using. It is quite transparent and not at all digital sounding. If you do some searches we have discussed actives quite a bit... there are several that have been recommended.


Widget

Steve Gonzales
04-13-2006, 05:24 PM
Thanks Widget, I'll wade through the mass. As for the 2421, I stand corrected. I own both types myself. At the risk of going OT, I believe the benefit is extended HF response, and the cost power compression. How would they differ if the actual working bandwidth doesn't take advantage of that extended range?. Hell, I've heard phenolic diaphragmed drivers sound smoother when used in a narrow 800hz-6.5/7khz bandwidth, I know, 6.5khz is pushing it, but you get my drift. As for E.Q., I thought that that was a no-no around here, for the most part.

boputnam
04-13-2006, 05:31 PM
Since Bo answered a question I thought was directed at me, I'll butt in and give an answer posed to him. :D Dammit, bo!! :bash: Don't you know this is Widget's place!! :baby:

I guess if you want any other ideas, you have to pm me Steve - and I say it's OK... ;)

And...


As for E.Q., I thought that that was a no-no around here, for the most part.Wow, then this really must be Widget's place. Most of the rest of us think quite differently... :nutz: (Steve - You can put any question of that sort in the same pm...)

Robh3606
04-13-2006, 07:17 PM
As for the 2421, I stand corrected. I own both types myself. At the risk of going OT, I believe the benefit is extended HF response, and the cost power compression.

Huh????

The benefit is extended HF response that you would see in the 4430. In the 4345 with the 2405 any additional gain is moot. Power Compression??? I don't understand that??? It's the same motor same power handling. The difference is the diamond surround.



As for E.Q., I thought that that was a no-no around here, for the most part.

Double Huh????

Why on earth would you think that. These old monitors and 1/3 octave cut only EQ's were made for each other. If you were doing an authentic studio type installation with a 4343/4344/4345 do really think there would be no EQ???

Rob:)

Steve Gonzales
04-13-2006, 08:28 PM
I've read that the diamond surround diaphragmed drivers have extended range over their smooth roll counterparts, but have less power handling capabilities. Power Compression, to me, is when the sound gets harsh, with a distinct loss of resolution and dynamics, non linear, maybe that too was a bad choice of words, but I meant it as an all other things being equal comparison between the 2420/2421. I did address the "moot point" of the extended HF response in the very next sentence, read it. I don't believe Widget was even addressing that difference, he was correcting me about the actual driver model used in the 4345. As far as E.Q. is concerned, your response appears to be a " Duh, dummy, what rock did you crawl out from under". That's what it reads like. From what I read around here, it seems like the "straight wire" school of thought is dominant, that is just the way I see it, from what I read around here, not for testing, just for the actual 2 channel systems that members actually use to listen to music . Of course I know about the benefits of an E.Q., been using them for 25 years!. You could be a bit less Duh and Huh, and a bit more constructive in a straight forward way. I'd appreciate that much more. I've learned that there is no such thing as a stupid question. If my remarks seem uninformed to you, then inform.

Robh3606
04-13-2006, 08:41 PM
The difference between Huh!! and Duh!!

Huh is when you reading something that is from a guy who has been on this site for what 2 yrs. He knows the history and this site well.

He says this



As for E.Q., I thought that that was a no-no around here, for the most part.



So you think Huh!! He knows better. Why would he think that!! Eq was a way of life for these speakers, they all went into professional installations with EQ.

So why would he think most of us would think EQ is bad?????


Duh

What I came across as. This is a very hard media to communicate in.


Rob:)

Steve Gonzales
04-13-2006, 09:07 PM
No harm no foul Rob, I'm getting a little better about at least including the possiblity of a unintended negative interpetation on my part, no sweat. I guess I'd better go back over some threads and re-read what has been said about E.Q.'s around here. Thanks friend.

Mr. Widget
04-13-2006, 09:30 PM
2421... soooother and HF extension. In the case of the 4345, it's the smoother part that we enjoy.

EQ.
I think it is safe to say that we have all screwed up a system with their use at least once in the beginning. It is also safe to say that some of us currently have them in the system and those of us preferring a more neutral sound would probably enjoy the sound better sans EQ.

Proper EQ.
Try to cut only. Try to avoid the use of EQ any more than +/- 3dB.
An RTA certainly helps... don't blindly try to set it flat... that will probably never be the best sound... not because of room curve issues but because you will likely add and subtract from bands next to each other and create massive phase shifts... you may not hear it at first... but it does take away from the "realness" of the sound.

Room Curve.
I think we have all come to the conclusion that the ideal in-room final response for a music playback system be somewhat downward tilting with the bass being a few dB up relative the HF.

Widget

Mr. Widget
04-14-2006, 12:02 PM
In answer to the frequently asked question, what is a good sounding active crossover....

http://cgi.ebay.com/SYMMETRY-ACS-1-Audiophile-Crossover-by-John-Curl-SUPER_W0QQitemZ9712438990QQcategoryZ14977QQssPageN ameZWDVWQQrdZ1QQcmdZViewItem


Unfortunately they are fairly rare... and this is one of those auctions where the item is described as being in excellent cosmetic condition while the photos seem to dispute that.... all that said, you might contact the seller. If this unit is working properly, you will have a hard time finding a better sounding crossover. I'd expect to pay $300+... but it's eBay so who knows?


Widget

Mike Caldwell
04-14-2006, 03:37 PM
Steve
If you wanted to try a different flavor of crossover for a little while I could send you a TDM 24CX2. I always have extras for backups. The 24CX2 is a two way stereo unit, I use them on my monitor systems. If you wanted a three unit I have a TDM 24CX3 you could try. Inputs / outputs are all XLR balanced.

Mike Caldwell

boputnam
04-14-2006, 04:40 PM
Room Curve.
I think we have all come to the conclusion that the ideal in-room final response for a music playback system be somewhat downward tilting with the bass being a few dB up relative the HF.I know I'm not 'sposed to be here butt (sic)...

What Mr Widget describes is the result one gets using Pink noise to EQ to flat. The net result, seen on an RTA of real data/information, is a response curve that slopes gently off progressing through increasing frequency.

boputnam
04-14-2006, 04:54 PM
Steve
If you wanted to try a different flavor of crossover for a little while I could send you a TDM 24CX2. I always have extras for backups. And, there's some used one's floating about - variable age and condition.

Dave Rat has some here --> Rat's Used Stuff (http://www.ratsound.com/forsale.htm).

and on eBay item 7404922057 (http://cgi.ebay.com/TDM-Audio-Model-24CX-2-Stereo-2-Way-Crossover_W0QQitemZ7404922057QQcategoryZ23790QQcmd ZViewItem), but this is an earlier vintage, evidenced by the TRS jacks. Still balanced, but not the XLR Mike mentioned.

4313B
04-14-2006, 04:55 PM
I know I'm not 'sposed to be here butt (sic)...:rotfl:

Feel free to toss a grenade in anyway. ;)

boputnam
04-14-2006, 05:06 PM
Feel free to toss a grenade in anyway. ;) OK!!


...those of us preferring a more neutral sound would probably enjoy the sound better sans EQ.:bs:

If you don't correct for the room excitations, you are not hearing a "neutral" sound (assuming I understand what you mean by that... :p ). All rooms behave differently - one must make adjustments since the speakers were not designed for their room.

4313B
04-14-2006, 05:11 PM
It wasn't until I heard the 4315 in a small studio in L.A. that I gained a full appreciation for proper EQ.

I can still hear those things to this day and have to laugh every time someone has something bad to say about the 4315 or proper EQ. ;)

One definitely has to know what the hell they are doing that's for sure. :yes:

I've heard the 4315 sound dreadful in some environments. But then I've had that experience with countless JBL models. One can really kill a JBL with a "bad" room.

edgewound
04-14-2006, 05:14 PM
OK!!

:bs:

If you don't correct for the room excitations, you are not hearing a "neutral" sound (assuming I understand what you mean by that... :p ). All rooms behave differently - one must make adjustments since the speakers were not designed for their room.

I disagree Bo...

A real live orchestra does not use EQ...so why should precision monitors?
:duck: :duel: :bash: Uh oh...veering off topic.

4313B
04-14-2006, 05:20 PM
A real live orchestra does not use EQ...so why should precision monitors?:rotfl:

Is it live or is it Memorex? :barf:

I always get a kick out of those drips that think they can recreate an orchestra in their 20 x 14 x 9 :applaud:

boputnam
04-14-2006, 05:23 PM
Steve:

Here's two examples of home EQ.

First, is the 4345's. Measured at about 17.5-ft - not optimum for the cabinets, but it is the family room listening position. EQ is a Klark Teknik DN370. Channel 1 (upper) is L. The two knobs with glowing halos are -18dB notch filters (Q=32) at approx ~30Hz (upper knob on each) and ~165Hz (lower knob on each channel) - nodes of excitation in my room. I've been through four EQ's in this signal path over time - this EQ has the best sound, and requires the least correction (adjustment) in the fewest places (Hz), all else being unchanged. This has proportional Q - the Q increases (i.e., narrows) with increasing adjustment, focussing the affect of the adjustment.

I posted a review a year ago (Review: KlarkTeknik DN370 graphic equalizer), or so. I use this same EQ in my FX roadrack - it wields incredible control to the engineer...

Second, is the Alesis Monitor One's in my study. Measured at 4.5-ft. EQ is the Ashly GQX3102.

Both these curves were established using laptop with SmaartLIVE 5.0 and Pink Noise, and the Transfer function (FFT). We have posted on this elsewhere, but in-short, Smaart takes a signal BEFORE the EQ (the reference signal) and compares it to a measured signal from a mic (Earthworks M30BX (http://www.earthworksaudio.com/25.html)). In Smaart, the reference signal is time-delayed to synch with the measured signal. As a FFT, the two signals are subtracted, and the difference plotted as a line. Where there are peaks, the singal path / room has added dB / resonance; where there are troughs, the signal path / room has cut dB / absorbed.

boputnam
04-14-2006, 05:24 PM
I disagree Bo...

A real live orchestra does not use EQ...so why should precision monitors?Ah, but they do, man!! :yes:

Why do you think they ALWAYS spend such dough during construction, and then are often having to refurbish and add acoustic panels in those halls? They try (and try, and try...) and physically tame the room.

Take a look around any symphonic concert hall - those really interesting panels are not there for looks - they need to be there to improve the balance, reduce nodes, enhance dispersion, reduce resonance, etc.

edgewound
04-14-2006, 05:59 PM
I figured that would get a response.:p

boputnam
04-14-2006, 06:24 PM
I figured that would get a response.:pDammit, edgewound!! :bash:

I shoulda know you were just tossing a grenade... ;) How'd I do...?

Mr. Widget
04-14-2006, 06:42 PM
:bs:

If you don't correct for the room excitations, you are not hearing a "neutral" sound (assuming I understand what you mean by that... :p ). All rooms behave differently - one must make adjustments since the speakers were not designed for their room.Fix the room!

No, you missed the meaning of my comment... I was suggesting that most people who apply EQ to their systems probably screw up the sound more by "fixing" it.

Widget

boputnam
04-14-2006, 06:51 PM
Yea, I know. Just tossing a grenade, you know!!

But, you are exactly correct. To much fussing with EQ introduces hoards of undesireable (and unintended...!!) phase perturbations. Littlest is best.

Steve Gonzales
04-14-2006, 07:36 PM
Thanks for all the great info. You guys crack me up with the way you bust each others balls :argue: :bash: :cheers:

Mr. Widget
04-14-2006, 07:48 PM
I always get a kick out of those drips that think they can recreate an orchestra in their 20 x 14 x 9 :applaud:Damn! You mean I can't get the sound of a 75 piece orchestra in my apartment? Why did I buy all of this Stereophile recommended equipment?:D


Widget

Steve Gonzales
04-14-2006, 07:50 PM
Damn! You mean I can't get the sound of a 75 piece orchestra in my apartment?


Widget Not according to B*se;)

edgewound
04-14-2006, 09:51 PM
Damn! You mean I can't get the sound of a 75 piece orchestra in my apartment?
Widget

No...but it is possible to to get the sound of a guitar, piano, bass and drums....jazz club style;). But y'already knew that.:)

Ian Mackenzie
04-15-2006, 01:39 AM
What was this thread about?:offtopic:

Incidentally there is an outfit in the States marketing a switchable 3 way passive crossover for speaker builders. I understand they have been seen at the CES. That might give your more joy than screwing about with an active system if you are just trying out ideas for kicks. As I recall they are only $200-300 bucks and you can dial in 6/12/18 db slopes and a range of crossover points with quality parts. Sorry I don't recall the Brand.

I think Steve would do well to visit Elliotts Sound pages. There are some excellent articles on crossover network fundermentals right up to advanced passive and active systems.

About the 4345, its sounds better in the mids and upper mids not just because of the diamond surround diaphragm. The breakup modes of the 2122H are far less annoying than the 2121, the baffles are offset giving smoother response in the critical midrange and the 3145 crossover is miles better than the 3143.

I've heard the 4343 and it sounds harsh and strident in its original form, particularly if it has not been carefully set up. Come to think of it I could also say the same thing about any uncoated diaphragm

I don't think Eq is the answer to domestic listening room and loudspeaker design issues but if it makes you feel better use it. The devil is in the details and unless used by an expert they and a nightmare.

Meaning no disrespect but Bo's room is far from the ideal and yes the Eq he had in there when I heard it did help the balance and the imaging.
I understand he now uses less and better Eq. (Also never let visitors screw with your graphic..you'll be sorry!)

The bottom line is your system is ony has good as your room. If the room sucks your rooted. Sell the flaming house or get divorced or go buy some top of the range AKG headphones and a Benchmark headphone amp.

Of course how many really top notch HiFi's systems use or need a 1/3 active graphic? Sweet Bugger all. If your system sounds like a PA then its probably a good idea.:barf:

Perhaps we are not talking Hifi here.:blink:

edgewound
04-15-2006, 12:58 PM
Wow...BTW...Sorry to go OT Ian.

I didn't really toss a grenade Bo, I surely got your opinion, and that's cool.

From a hifi listening standpoint I've discovered throughout the years that my greatest satisfaction has come from the minimalist approach, equipment-wise. The more inherently accurate and natural sounding the speakers are, the less tweaking needs to be done with EQ. Honestly...I like no EQ, no preamp...just disc player through a volume control straight into a good amp and then the speakers. For me, that really uncovers good or bad recordings with less stuff in between the disc and the music.

I'm just talking 2 channel stereo, not home theater, but that might work well too...DVD direct from the analog outputs to amps...haven't tried that yet.

I think most home listening rooms that aren't dedicated would do fine with wall to wall carpeting and some drapes or other soft coverings to quell wall reflections in addition to upholstered sofas, chairs, etc.

Ok...that's my opinion...from the "less-is-more" school of thought...the speakers should required very little...if none at all...electronic "fixing".

Have a Happy Easter:)

Steve Gonzales
04-15-2006, 01:37 PM
Well, I've been running a tri-amped system for some time now, so I'm fairly familiar with the basics. I'm not doing this for kicks, I've got some 136a's that have been completely, professionally rebuilt, some 2123H's, 2397/2441's and about 4 pairs of 076's, so I'm serious about building a four way. I just wanted to get some advice about the crossover choices. I figured that I could go total active 4 way, tweeked bi-ampable 4way passive or custom 4 way passive. I admit that my questions are fuzzy but believe it or not, the answers would allow me to connect some dots about my final choice. I also might choose the 2235H for the bottom and I can get some 2122H's also, so I really need to figure this all out, looks like I'm leaning towards full active. Thank you, gentlemen, great info.

boputnam
04-15-2006, 01:55 PM
...I surely got your opinion...Wasn't so much opinion, as reality. I was classically trained on bass trombone, and my sister is an opera singer, so I've spent ample time in many halls, nationwide as many of us have.

Acoustic architecture is critical to allowing for a "natural" sound to be heard by both the audience and the artists. Many stages are dead - so dead the orchestra cannot hear themselves. Others are too loud.

Anyway, following are a few things to make the point.

First, the acoustic engineer who has done great things for the Boston Symphony Orchestra, Dr. Beranek, and second, a quote relating to renovations at Davies Symphony Hall in San Francisco - renovations that cost nearly half the original capital cost. But this problem is almost universal to big halls.

----------------------------

Louise M. Davies Symphony Hall, the concert hall (http://en.wikipedia.org/wiki/Concert_hall) component of the San Francisco War Memorial and Performing Arts Center (http://en.wikipedia.org/wiki/San_Francisco_War_Memorial_and_Performing_Arts_Cen ter), was built in 1980 at a cost of $28 million to give the San Francisco Symphony (http://en.wikipedia.org/wiki/San_Francisco_Symphony) a permanent home. Previously, the Symphony had shared the neighboring War Memorial Opera House (http://en.wikipedia.org/wiki/San_Francisco_War_Memorial_Opera_House) with the San Francisco Opera (http://en.wikipedia.org/wiki/San_Francisco_Opera) and San Francisco Ballet (http://en.wikipedia.org/wiki/San_Francisco_Ballet). Its construction allowed the symphony to expand to a full-time year-round schedule.

Designed by Skidmore, Owings & Merrill (http://en.wikipedia.org/wiki/Skidmore%2C_Owings_%26_Merrill) and Pietro Belluschi (http://en.wikipedia.org/wiki/Pietro_Belluschi) along with acoustical consultants Bolt, Beranek and Newman (http://en.wikipedia.org/wiki/Bolt%2C_Beranek_and_Newman), its modern design is visually elegant both inside and out. A "cloud" of movable convex acrylic reflecting panels over the stage enables the acoustic space to be adjusted to suit the size of the orchestra and audience, while adjustable fabric banners around the auditorium can alter the reverberation (http://en.wikipedia.org/wiki/Reverberation) time from approximately one to 2.5 seconds. Howevever, the hall's large volume and seating capacity (http://en.wikipedia.org/wiki/Seating_capacity) and the relatively immature knowledge of acoustics (http://en.wikipedia.org/wiki/Acoustics) at the time initially resulted in less than ideal results. Acoustical renovations under the direction of Kirkegaard Associates (http://en.wikipedia.org/wiki/Kirkegaard_Associates) were completed in 1992 at a cost of $10 million, resulting in substantial improvement.

The modifications included narrowing and shaping the walls above the stage to reduce the volume of space and increase useful reflections, replacing the cloud of reflector discs with a more effective array that covers a larger area and is computer adjustable, pulling in the walls of the floor-level seating to make the audience area narrower and more rectangular, adding aisles to replace the former continental seating, adding diffusing elements in various parts of the hall, and increasing the "rake" of the floor seating to provide better sightlines. In addition, risers were installed on stage to allow the musicians to both see and hear each other better. These and other improvements enhanced not only the acoustics but also the hall's beauty. The current seating capacity is 2,743.

--------------------------------

Support local music! :applaud:

boputnam
04-15-2006, 02:05 PM
...I figured that I could go total active 4 wayIf you do choose to get so complicated, Steve (and wanna spend all the dough needed on extra amps... :spin: ) you might consider trialing something like the BSS FDS-334T/336T MINIDRIVE (http://www.bss.co.uk/includes/product_sheet_include.aspx?product_id=28) or KT DN9848 (http://www.klarkteknik.com/DN9848E.htm) units. Their output channels have multi-point parametrics for fine tailored control, as well as delays for time-alingment, shelving filters, etc.

If you have, or can borrow the needed acoustic measurement gear, you might have a real interesting time seeing what you can hear...

Steve Gonzales
04-15-2006, 02:14 PM
Thanks Bo, I've got a tri-amped system already so it's not that much more complicated. I've got the midbass amp already too. What I need is the crossover and enclosure. I look at my system as an evolution in progress. BTW, that auditorium/concert hall is B-E-A-utiful!!!

edgewound
04-15-2006, 02:25 PM
Wasn't so much opinion, as reality. I was classically trained on bass trombone, and my sister is an opera singer, so I've spent ample time in many halls, nationwide as many of us have.

Support local music! :applaud:

Bravo to supporting local music.

Bo, I have utmost respect for your opinions and your technical knowledge of live sound and music...recorded or otherwise....and I'm not arguing your points.

My point is...if all that technical science on acoustic architecture and electronic tuning were mandatory in getting a satisfying musical listening experience at home....no one would ever do it. Thank God all those symphonic halls exist, and the geniouses that design and engineer them.

Most listeners are not going to... nor be able to afford...to build a money is no object listening room. I think great sound is do-able using minimalist approaches to system design...that's all.:)

And....most local music venues...bars, restaurants, nightclubs, city concerts in the park, are hardly designed from the ground up for great acoustics. That's not my opinion...it's my experience. Been there...still doing it:band: :)

Mr. Widget
04-15-2006, 02:28 PM
If you have, or can borrow the needed acoustic measurement gear, you might have a real interesting time seeing what you can hear...I have to say that without access to real measurement equipment you will be playing around in the dark. It is true that the ultimate judge for how successful you are will be you and your ears, but having set up quite a number of multi-amped systems, I know you will always be fiddling around with it because this or that recording doesn't sound quite right.

Even with the measurement equipment and the knowledge of how to use it properly, you will still need to tweak it a bit, but it will make your ultimate results so much more satisfying when your system is set up properly. I suppose this is why some think that a properly set up passive crossover sounds better than an active one.


Widget

edgewound
04-15-2006, 02:43 PM
I suppose this is why some think that a properly set up passive crossover sounds better than an active one.

Widget

Very valid point. Constantly tweaking the crossover or EQ doesn't strike me as being a rewarding listening experience. Some like to have more stuff to fiddle with...and there's some fun in that too.

Ian Mackenzie
04-15-2006, 04:11 PM
Well, I've been running a tri-amped system for some time now, so I'm fairly familiar with the basics. I'm not doing this for kicks, I've got some 136a's that have been completely, professionally rebuilt, some 2123H's, 2397/2441's and about 4 pairs of 076's, so I'm serious about building a four way. I just wanted to get some advice about the crossover choices. I figured that I could go total active 4 way, tweeked bi-ampable 4way passive or custom 4 way passive. I admit that my questions are fuzzy but believe it or not, the answers would allow me to connect some dots about my final choice. I also might choose the 2235H for the bottom and I can get some 2122H's also, so I really need to figure this all out, looks like I'm leaning towards full active. Thank you, gentlemen, great info.

The problem is you need to know how to go about it and that is why I refered to Elliotts Sound Pages and hence the hints from other posters in this thread. Quad amping isn't necessarily the answer nor the most practical way of going about it.

What you could do is buy a SH Driverack for experiementation and get it to give you a flat response. Then somehow measure the voltage drives to the components and then arrange a high quality work around. A better way is just a bunch of DEQX's .

hapy._.face
04-15-2006, 05:57 PM
Having a quad amp system could be heaven or hell- depending on the set up. If you give an average guy a few dozen knobs to turn- he will probably tweak to his satisfaction- even if that means the recording integrity gets tweaked, too. I (personally) would want to know what the room was doing (via software) before I introduced such a complex system.

Widget's notion of letting your ears be the ultimate judge (while correct) seems only valid if your ears have been trained to know proper sound. Most people don't know proper sound unless they have been in the industry, or associated with a proper system.

We all know that amps perform differently- depending on the volume. Now multiply that times four. Factor in the extra protection that a quad amp set up usually requires, the symbiotic relationship your preamp/amp takes on- and you might be so far removed form the original signal (sounding "good" prehaps) that nothing really matters.

I agree with the whole 'less can be more'. I prefer to introduce the least. Keep it simple. An excellent passive- made to the exacting specs of your drivers- is (IMO) the ultimate way to go. I can see biamping - but I would stay away from tri/quad with full active unless I really knew what I was doing.

Now I have a question - don't most (off the shelf) active Xovers only address slope and freq? How do they compensate for Fs? How can they perform as good as a custom passive if they are (indeed) this vague/general?

edgewound
04-15-2006, 06:12 PM
Now I have a question - don't most (off the shelf) active Xovers only address slope and freq? How do they compensate for Fs? How can they perform as good as a custom passive if they are (indeed) this vague/general?

Choose your crossover points well within the flatest, most well behaved response areas of each driver....then apply eq cut to the offending areas should there be any.

Robh3606
04-15-2006, 06:34 PM
Now I have a question - don't most (off the shelf) active Xovers only address slope and freq? How do they compensate for Fs? How can they perform as good as a custom passive if they are (indeed) this vague/general?

Your typical 24dB L-R analog crossover has two basic user controllable parameters. Attenuation and what the crossover frequency is. That's it. You are adjusting the over all level, the level in each passband and in a 2 way where the crossover point is between the drivers. Not sure what you mean about Fs?? If you mean the woofer well the box handles that. The rest of the drivers are wide open you can drop the crossover bellow Fs on a compression drivers rather easily.



Having a quad amp system could be heaven or hell- depending on the set up.

It's hell plain and simple. The more complexity you add the harder it is to make it sound right. Getting it balanced right even with an RTA, so it really sounds "right" is an exercise in real patience. I may take you a month before you finally have it dialed in where you want it. Chances are excellent it won't be the same curve you worked hours on with careful adjustment on levels and set-up when you started. When your all done you have to record all the settings and take a curve snap shot so you can get back there if anything gets changed. It sounds so simple just set-up the microphone watch the curve on the RTA when it looks good your done. Sure you are!

The one thing I have learned doing active is just how hard it is to design a really good crossover. There is a reason the passives have asymmetrical slopes and non textbook implementations. Some of these driver integrate best that way. That's why you always build the passive if for example you are going for a clone. You may never be satisfied with what you get using the fixed filters in these inexpensive crossovers. More importantly you may never get to hear the drivers integrated properly like a passive network can do.

Rob:)

Mr. Widget
04-15-2006, 07:30 PM
What he said...


Widget

Ducatista47
04-15-2006, 07:34 PM
Well, I've been running a tri-amped system for some time now, so I'm fairly familiar with the basics. I'm not doing this for kicks, I've got some 136a's that have been completely, professionally rebuilt, some 2123H's, 2397/2441's and about 4 pairs of 076's, so I'm serious about building a four way. I just wanted to get some advice about the crossover choices. I figured that I could go total active 4 way, tweeked bi-ampable 4way passive or custom 4 way passive. I admit that my questions are fuzzy but believe it or not, the answers would allow me to connect some dots about my final choice. I also might choose the 2235H for the bottom and I can get some 2122H's also, so I really need to figure this all out, looks like I'm leaning towards full active. Thank you, gentlemen, great info.
Steve, 2245H's are plentiful, new to basket cases. If it is experimenting you are after, nevermind. But you have most of a 4345 pair in hand. Go 18" instead of 15". Build those and biamp them, and you will create something more rewarding to listen to than any amount of experimentation will likely ever produce. Believe me, I know how rewarding listening to a biamped, four-way 2245H-based system done right is. Widget and Subwoof feel a 2" compression driver is preferable for high spl's, and crossover possibilities are quite open. Who knows, you might bring the 4345 sound to a new level and we will all beat a path to your door.:D

Personally, I wish someone would update the design with current (improved) JBL drivers that are here and now. Problem is, it would take Greg Timbers to design the crossovers and baffle. I hear he is future-looking and otherwise engaged.

But bottom line, I think you will like your project much better in the end if you use the 2245 and 2122 drivers. What a potent combo they are.

Clark in Peoria

Mr. Widget
04-15-2006, 07:42 PM
Widget and Subwoof feel a 2" compression driver is preferable for high spl's...I think 2" drivers are preferable at whispering low SPLs too... I am not really into really loud these days... getting older you know.;)


Widget

hapy._.face
04-15-2006, 07:48 PM
I think 2" drivers are preferable at whispering low SPLs too... I am not really into really loud these days... getting older you know.;)


Widget


This guy isn't into 'loud' either :p

http://i13.photobucket.com/albums/a253/ameristalgia/Mouse.jpg

4313B
04-15-2006, 08:13 PM
Personally, I wish someone would update the design with current (improved) JBL drivers that are here and now.Ok! That's easy! Shazam!

norealtalent
04-15-2006, 08:15 PM
You mind sending those over to my house for a while?

edgewound
04-15-2006, 08:17 PM
Ok! That's easy! Shazam!

Ahso....American market not worthy, Giskardsan:blink:

Ducatista47
04-15-2006, 08:18 PM
Sorry to have to ask, but I'm new at this, Giskard. What are they, are they available in North America and do they cost less than my house?

OK, the rest of the images have loaded and my ignorant questions have been answered. Thank you!

I suppose they have that darn oriental market bloated midrange.

Clark in Peoria

4313B
04-15-2006, 08:26 PM
I think they're like $7,000 each.

Ducatista47
04-15-2006, 08:31 PM
Hey, if those are current, Northridge has JBL blue paint they could sell us.
Sorry to go:offtopic:


Clark

Steve Gonzales
04-15-2006, 10:55 PM
I (personally) would want to know what the room was doing (via software) before I introduced such a complex system.
Widget's notion of letting your ears be the ultimate judge (while correct) seems only valid if your ears have been trained to know proper sound. How would you know what the room was doing without the system in the first place, you gotta have it first to measure what it's doing in the room?. Secondly, if you've got enough of an idea about what you want it to sound like, within the system's limitations, you aim for that. Ultimately, proper sound is what agrees with your own personal taste regardless if it satisfies strict professional set up protocal/ criteria or not. Am I saying that Joe Blose should go out and wing it, NO! I've had some good measure of sucess so far, I have Dave Brink in my corner and that accounts for a good portion of my success, combined with about 25-30years of experience with JBL systems and how they do and should sound - to me--.


We all know that amps perform differently- depending on the volume. Now multiply that times four. Factor in the extra protection that a quad amp set up usually requires, the symbiotic relationship your preamp/amp takes on- and you might be so far removed form the original signal (sounding "good" prehaps) that nothing really matters. I've found that an electronic crossover is extremely flexible when it comes to adjusting/matching the different output levels and the ability to adjust the crossover frequencies is outstanding also. Again,I am not promoting the idea that Joe Blose "wing it", I just want to respond to what I think is much too scary sounding for those also contemplating a fully active system.


I can see biamping - but I would stay away from tri/quad with full active unless I really knew what I was doing. While not as many amps are being used, I think that one should know just as much while contemplating a bi-amp system too. I don't really see that much difference. You still have to consider levels, the room and equipment, basically, just the same. We have the good fortune of expert advice and experience here to lean on and learn from, it's gonna be okay :D

Steve Gonzales
04-15-2006, 11:01 PM
Steve, 2245H's are plentiful, new to basket cases. If it is experimenting you are after, nevermind. But you have most of a 4345 pair in hand. Go 18" instead of 15".
But bottom line, I think you will like your project much better in the end if you use the 2245 and 2122 drivers. What a potent combo they are.

Clark in Peoria Thank you Clark, it has definately crossed my mind:D

Ian Mackenzie
04-16-2006, 12:26 AM
Steve,

Rob raises some good points.

This is not an exact science and in the end you have to trust the ears and not necessarily your own.

Most active analgue crossovers only give you one slope, typically 18 or 24 db these days and variable frequencies.

You really need to try 6/12/18 and if available vary the Q factor or knee if the corner frequency. I have built such a unit but it is very complex.

The point is though none of this is a plug and play situation like putting an LE85 into a L220 and expecting it to be quantum leap in improvement unless you strike it lucky. More likely the L220 sucked period and any change was a good change.

In my own experience what I first thought was perfection as a self designed crossover was finally proven to be crap compared to a professional effort from the likes of G.T. I mean even the drivers are carefully chosen to work together and some drivers like the 2122H in the 4345 were specifically engineered for the task at hand ..not a re worked LE10 like the 2121 in the 4343. Hence I don't waste my time pretending to be a loudspeaker designer but rather develop an appreciation for fine JBL vintage designs like the 4345.

I must admit though it is fun trying and that is where the satisfaction , the passion and enjoyment of rolling your own system comes into play. But don't kid yourself you have got it right first pop...particulary a 4 way.

If you could borrow a digital unit from a member and find the right mix of slope and crossover point then buy or make up a customised unit from Marchland that would make an excellent setup.

Steve Gonzales
04-16-2006, 01:00 AM
This is not an exact science and in the end you have to trust the ears and not necessarily your own.I'm trying to figure out what this means Ian. What I hope it means is that I might need someone else's opinion when diagnosing or tweaking the system initially, that may be, we'll see. I trust my own ears to tell me what I like with the final settings. I appreciate the advice, but have to admit that some of it sounds like preparing for a trip to Mars, rather than adding 10" woofer-etc, and I don't see it that way. I've now decided to go full active 4 way, from a full active 3way. Playing around with a mix of odd and even order slopes will probably not happen for a good long while, but it is nice to know that there are plenty of configurations to explore, thank you. There are known enclosure volumes/ construction techniques and T/S parameters for the drivers. I've got good baseline information, it should be fun.

P.S.-BTW, I've been very careful about my stated expectations, I want to reinforce the fact that I never implied or meant to imply that this is a cake walk.

Ian Mackenzie
04-16-2006, 02:44 AM
I appreciate the advice, but have to admit that some of it sounds like preparing for a trip to Mars, .

Actually Mars is one of my favourite gettaways and quite romantic..just ask Arny.(Total Recall)

Semi seriously, its all meant to be fun and of course it all depends how serious you wanna be. And another set of years and a glass of Red makes it all worthwhile!

hapy._.face
04-16-2006, 07:15 AM
How would you know what the room was doing without the system in the first place, you gotta have it first to measure what it's doing in the room?


There are acoustical properties already at work in the room before you put in a quad amp system or even pass gas. You can address the room- all by itself.



Secondly, if you've got enough of an idea about what you want it to sound like, within the system's limitations, you aim for that.


...if that's your goal. Great! :)
If your audio goals are to maintain the integrity of the original recording- you aim for that.




Ultimately, proper sound is what agrees with your own personal taste regardless if it satisfies strict professional set up protocal/ criteria or not.


...I guess. I know a few recording engineers that would vomit at hearing this. The imperical system of R&D employs guys with golden ears- trained pros. These guys get their hearing tested regularly- and know what to listen for- it's a full time occupation. You are totally right, though- it's ultimately the end user's choice should anyone choose to butcher a perfectly good recording in the interest of 'sounding good'. I don't think you'll be doing that- but this Joe Blose guy you refer too...

If I want to build my own house and maintain the architectural dicipline of the neighborhood- I should probably hire a pro. If I want to build a get away cottage in the sticks- I can draw up any plans I like. Both are functionable dwellings; One is certainly proper.





I've found that an electronic crossover is extremely flexible when it comes to adjusting/matching the different output levels and the ability to adjust the crossover frequencies is outstanding also. Again,I am not promoting the idea that Joe Blose "wing it", I just want to respond to what I think is much too scary sounding for those also contemplating a fully active system.


I think if you invest in the highest quality active xover you can financially stomach (probably should build it yourself) and integrate variable slope rates, model it to the drivers you are using (not a generic "off the shelf"), get some input on your room acoustics- set the knobs to compensate for it all- and keep it that way- you'll be lovin' life! In theory- an amp for each driver is ideal.



While not as many amps are being used, I think that one should know just as much while contemplating a bi-amp system too. I don't really see that much difference.



OK- perhaps for you. Most people don't understand that amps have unique personalities. Every position on the volume knob has an influence on that personality. The relationship the amp has with the load, and the variables of using four amps in a four way load all set to their respective levels- controlled by a main volume- gets infinately more complex with a quad system.

The cost of operating 4 amps gets expensive, too. I hope that for all the effort and expensive- you arrive at a point where you can say it was worth it. It is a big leap- but I know you can pull it off, Steve!



OK- now a point off topic:
Isn't it interesting how we need at least two additional posts just to explain what we meant in our first one? Isn't it also interesting the way we defend our positions- yet we come accross as attacking another's intentions? If this were speech- we would be making fun jabs and laughing. In text- it's like a gauntlet has been waved. Strange stuff this is...

norealtalent
04-16-2006, 07:44 AM
... More likely the L220 sucked period and any change was a good change.

In my own experience what I first thought was perfection as a self designed crossover was finally proven to be crap compared to a professional effort from the likes of G.T. I mean even the drivers are carefully chosen to work together and some drivers like the 2122H in the 4345 were specifically engineered for the task at hand ..not a re worked LE10 like the 2121 in the 4343. Hence I don't waste my time pretending to be a loudspeaker designer but rather develop an appreciation for fine JBL vintage designs like the 4345.

I must admit though it is fun trying and that is where the satisfaction , the passion and enjoyment of rolling your own system comes into play. But don't kid yourself you have got it right first pop...particulary a 4 way.



In contrast to the disregarded L220's that I have heard many pair of, the 4345 is one of the few pair of JBL's that I have not had the pleasure of auditioning, therefore, I will not be so arrogant as to speculatively commment on their overall sonic qualities or lack there of. Keeping on topic, the 4345 uses both active and passive crossover components to achieve such a revered status as a 4 way system. Like all vintage JBL's, it was designed and engineered by JBL professionals to perform a specific purpose, with specified reproductive accuracy. Granted, the L220 was "not in the same room" as the 4345, however, the primary design parameters were the same, to build the most excellent loudspeaker for the intended purpose as defined by production and marketing profitability. In the case of the 4345, it was obviously modeled on 4343 design parameters with improvements in driver selection, crossover topology and cabinetry design. Was this an improvement over the 4343? I imagine so. I've never been able to personally compare the two so I am not qualified to do anything more than speculate. What I can definitively state is that what I find to be the most offensive design falacy inherent to the 4343 was the 2307/2308 horn/lense. Although the offense is addressed in the 4345 crossover, the 2307/2308 was still chosen for use in the 4345.
I am sure JBL did not kid themselves into thinking they had it right the first time either. JBL has never built a perfect loudspeaker and never will. As we all know, there is no such thing. They did the best that they could do with what they had to work with (and they're still working on it.)

My point? Why would a curious mind be encouraged to do any less here?

Ian Mackenzie
04-16-2006, 08:11 AM
I without getting bogged down in the 2307 thing there are lots of reasons why the horn needed taming in the 4343. (see the 4343 upgrade thread ..incl looping it through a 52 uf capacitor!)

I never suggested the 4345 was the greatest thing since sliced bread but it is a good example of how well 4 drivers can be blended. But blending 4 drivers is much harder than 3 as you have no base line reference ..if you know what I mean and it is very confusing to adjust at the best of times.

As to ascribing to an active 4 way right off your pants, I think it's a great diy project and lot and lots of fun but totally false to lead anyone with the impression that you can sort it out with a handful of posts on a forum. I mean look at Kens Westies, he spent ages tweaking them and they were pre engineered from the ground up.

I mean imagine you build/ design/assemble model powered planes for a living and your pretty glued up. Its not quite the same as rolling a Concord off the production line (an oldie but a goodie but very carefully thought out.).

A 4 way is all about balance (as was the Concord) and that ain't easy. Anyone who thinks they can rack up a 4 way like a real JBL system and shoot the breeze before even starting is definately not talking about the classic JBL's we all love .

norealtalent
04-16-2006, 08:29 AM
If you're not making any mistakes, it's just because you're not doing anything...
(no wonder I'm soooo busy!):p

4313B
04-16-2006, 09:18 AM
Granted, the L220 was "not in the same room" as the 4345, however, the primary design parameters were the same, to build the most excellent loudspeaker for the intended purpose as defined by production and marketing profitability.I suspect Ian might have some information the general public isn't privy to. Suffice it to say the L220 never has been, currently isn't, and never will be very well regarded in certain circles.

PR15C, LE14H, LE5H, L94, 076, N220, C220 - what on earth could possibly have been the problem? Well, all I can say is it certainly wasn't the individual components. I simply cannot elaborate even after these 25 years have gone by. :no:

Regardless of any kind of negative light it's always existed in, it did have a 3 year run so there are still models out there and it was considered a "fun" or "acceptable" loudspeaker by some and that's perfectly fine. To each their own. I'm glad JBL was able to sell them. A few people built custom versions using the Loudspeaker Component Series before JBL came up with the first factory model back in '78. The network used was the LX30 and the 077 was used in place of the 076. The first custom iteration I saw was back in '76, two years before the factory model.


My point? Why would a curious mind be encouraged to do any less here?My point? Just do it. No real need to yammer on about it. If one posts about such stuff instead of just going out and doing it one is bound to get all kinds of input. I personally hear "won't work" fairly often, not so often these days as in days gone by. Sometimes I'll go ahead and do it anyway to find out why it won't work and sometimes I'll look at the cost involved and realize I simply don't care enough and bag the thought.

Robh3606
04-16-2006, 10:44 AM
Quote:
Originally Posted by Ian Mackenzie
This is not an exact science and in the end you have to trust the ears and not necessarily your own.

I'm trying to figure out what this means Ian. What I hope it means is that I might need someone else's opinion when diagnosing or tweaking the system initially, that may be, we'll see. I trust my own ears to tell me what I like with the final settings.


Hello Steve

I know exactly what he's talking about. The original designers as an example. If you were trying to build an all active 4345 you would need to hear a stock 4345 as a point of reference. I always build a DIY with a reference speaker I like as a baseline. I am essentially using the designers ears as my starting point. .


Again,I am not promoting the idea that Joe Blose "wing it", I just want to respond to what I think is much too scary sounding for those also contemplating a fully active system.



The comments are not to scare anyone just to let you know it's not as easy as it sounds. Giskards right Just Do It.


Rob:)

Zilch
04-16-2006, 12:23 PM
Steve, it's absolute lunacy to embark upon this without measurement instrumentation.

Do you have an RTA yet?

alskinner
04-16-2006, 02:43 PM
If your serious about building a 4 way active system similar to the 4345/4344 let me know. As stated in previous posts setting up a 4 way active is anything but quick and dirty. It took me almost 2 years to get the system exactly where I wanted it, but the sound, rewards and knowlege were defininitely worth it. I have the passive crossovers, but still prefer the active setup better. You can look at some of my previous posts and see some of the growing pains.

AL

Steve Gonzales
04-16-2006, 02:56 PM
If your serious about building a 4 way active system similar to the 4345/4344 let me know. As stated in previous posts setting up a 4 way active is anything but quick and dirty. It took me almost 2 years to get the system exactly where I wanted it, but the sound, rewards and knowlege were defininitely worth it. I have the passive crossovers, but still prefer the active setup better. You can look at some of my previous posts and see some of the growing pains.

AL Thanks AL, I will take a look. One thing I appreciate is that people that know me, know that I'm not just speculating about this project. It's taken some time, money and effort to gather the drivers and horns. Like Giskard said: "Just do it!". Thanks fella's.