Printable View
Vuki:waver:,Quote:
Originally Posted by vuki
Can you expand on how one should go about varying the inductor value for low/midrange for the 604k? Lets's say you start with inductor value of 1.7 mH (like in JM's filter I use) for the low pass part. What happens if you increase or reduce the values?
Regards/Naimare
It's quite a simplification but; in a 12dB/oct. lowpass filter by changing L value (up to +/-15%) you mostly change the the slope of bass/midrange; higher L value slope goes down, smaller L value slope goes up. By changing C value you mostly influence the "knee" of the lowpass; higher C value = sharper knee...Quote:
Originally Posted by Naimare
vuki :
I tried your hi pass XO section with my 605s , and it sounds great . What did you use for the coils ?
Todd:
Thank you for the Vocal Master plug . Limited BW, yes ," VOCAL " , everyone else has an amp and speakers. BTW to sound right they must be driven by a Shure : VA300, VA302 or PM300 , all of wich are current amplifiers. YES one VOLT in produces one AMP out. This makes the AMP into a equalizer, the output voltage follows the column impedance curve.
Don
Nice to hear you like it - probably it works on 605 too, but it is designed for mantaray type horn- IIRC 605 has old, multicell type horn? It could be that the responses are similar enough. I used aircore inductors. Since both inductors on highpass filter are in series with relatively high valued resistors, Rdc of inductor isn't important -the cheaper the better ;)Quote:
Originally Posted by donaldpatten
Hey Don,
Yeah, we used to call them the "VocalBlaster" - and the speakers "Sound Collyum's"... :)
Really quite inventive, though, wouldn't you say?
Quote:
Originally Posted by vuki
Vuki: I believe you mentioned that your XO was designed to address the rising output of the woofer at higher frequencies, which seems to be a primary cause of the "beaming" I'm experiencing...Is there a way to change any of the XO values to "control" the amount of output in the range of frequencies where the beaming occurs?
Hi Seadweller,
I don't understand your question, but using my crossover there shouldn't be any beaming.:confused:
Sorry, I know very little about crossovers, so my questions are probably strange, so I'll ask it in a different way; similar to changing R3 (4R7) on your XO to increase/decrease high frequency energy, is there a component in the bass driver section of the XO that could be changed to increase/decrease the amount of energy from the woofer near the crossover frequency?Quote:
Originally Posted by vuki
Hopefully, this makes more sense! :)
Quote:
Originally Posted by Seadweller
There are two aspects to your question here
1)-The energy coming out of the woofer & the tweeter need not be adjusted with two separate controls, as they are relative to each other, and by controlling only one of them does the job. As the woofer deals with most of the wattage involved, it is wiser and cheaper to control only the tweeter.
2)-The frequency respose pattern control of the woofer and tweeter at the cross-over-point, which is probabely the actual intention of your question, is a totally different thing. Here also mostly the choice of a contour control is usually given only for the tweeter, as our aural sensitivity usually is always in the area where the tweeter operates. The woofer is usually contoured/crossed-over in a fixed manner depending on the type of driver choice and type of application etc. etc. One can match and use any driver with another any other driver. But it is always better to have two units of similar sensitivity and a FR which is easily mate-able, otherwise one loses efficiency.
Now coming to "Vuki's" crossover, it has already taken care of the typical midrange brightness of the woofer, by reducing it and tapering it off with a slope starting much earlier in it's frequency response curve. This is done by the 3.6mH and 15mF. The tweeter also is similarly treated to dampen the brightness. So now only remains the choice of a HF control for the whole system. You can do that by varying the value of R3 between 3R3...to...6R8, as already suggested by him.
Aditya
Thanks Aditya! :)
Vuki:waver:,
I may try your filters as well!
Does your filter address the 604 "phase issue" as JM's filter is aimed at solving? What capacitors do you use? Paper-in-oil are exceedingly smooth sounding in my filter but lacks a bit in bite and excitement. I would like a more upfront presentation combined with the "naturalness" of PIO...(maybe you can't have it all).
Regards/Naimare
Naimare:
when designing crossover I'm not so much focused on any particular technical parameter - it has to measure correct and then, of course, it has to sound good. Usually it takes some time to get it right both ways.
There is no singular "perfect" solution: it is always bunch of compromises and designer's choices. That's why there are so many commercial loudspeakers that use same drivers but usually sound quite different.
So, regarding my crossover, as with any crossover you wanna try, I suggest you to build it with the cheapest parts available, and then, if you like it, swap those for high quality parts of your choice to "spice" the sound.
In this project I used Audyn MKP capacitors from german mannufacturer Intertechnik. When money is no object I like to use Mundorf's Supreme MKP's. IMO this are finesses - if the loudspeaker doesn't sound right with bipolar elcos even Duelunds won't make it better.
Hi,Quote:
Originally Posted by vuki
You are most welcome !:)
Thanks Aditya! Please forgive my ignorance; I have an additional question, but I'm not sure how to ask it...:)Quote:
Originally Posted by aditya
In Vuki's XO, is it possible to change the degree of the slope as it approaches the crossover point? In other words, can the response be tapered off more aggressively as the crossover point nears, by changing the capacitor value for example? I believe Vuki mentioned that you cannot control this with an L-Pad.
I'm still struggling to learn this stuff!
Seadweller:
You will change the quantity of the midrange (approx.400-2000Hz) by varying value of coil, and you will change the quantity of the narrow band in upper midrange (approx. 1000-2500Hz) around the crossover point by varying capacitor and by that you will also change the quality of overlap ("phasewise").
Hi Seadweller,Quote:
Originally Posted by Seadweller
First thing is ....you are most welcome to ask your doubts.:)
Coming back to your question..........
I am a little confused here as to what exactly you mean or want here.:)
Have you already tried this crossover and still find it shouty or it is just an academic question ?
B'coz this crossover of Vuki has already done a very aggressive cut at the area of that shouty-ness. It seems to me to be nearly (-)15dB around 2.5/3KHz area which creates that shoutyness. Any further cut is really not necessary.
Yes, you can adjust the slope by changing the caps, and I had suggested the same to you in my earlier post as a starter kind of a thing. But changing the caps alone also has its limitations unless you also change the coils. For the woofers caps change the 2nd slope and thus its angle/knee, whereas the coils set the first slope. In the case of tweeters the reverse happens.
I will suggest you to go ahead & try this crossover. It will do the job. Buy the cheapest components and assemble the whole thing on the floor with the wire-connections hand-twisted. Hear the results, and if necessary slightly fine tune it. Once confirmed about the results......replace with quality components.
But first confirm a leak-proof cabinet (it is VV important), and have/borrow a good amp/source setup.
Aditya
Hi aditya:waver:,
So for example, if I add a second coil of 1.9mH in series to the existing 1.7mH to get to Vuki's 3.6mH for the low-pass part in my Jeff Markwart crossover (but keep the capacitor value at 16microF) - what change would I experience with my 604k's (in theory that is)?
Regards/Naimare
Hi..:),Quote:
Originally Posted by Naimare
You will now get a total value of 3.6mH. So your 604K's behaviour now will be lot less shouty. But unless the slope of the tweeter also is matched properly/equally, you will hear a slight shelving kind of a bump around 1500Hz and onwards, b'coz the reduction in loading from the woofer's side forces some of this zone to be shared by the tweeter. Thus it will sound now tweeter-harshy. You can adjust it by reducing the value of the tweeter's series cap (it is always the 1st one incase there are many. I don't have the JM ckt with me. So guesstimating.:)
Thank you Aditya...Yes, my question is more academic at this point...The gentleman that has been building my XO's is actually building the HF section for me, because he wanted to test it on his own system (605's)...Evidently, he was pleased with the result...Quote:
Originally Posted by aditya
He already built an XO with separate HF and LF boards, so I'm going to try adding the HF circuit to his LF circuit...Then I'll try Vuki's LF circuit...
I'm trying to learn/understand what effect changing the values of certain XO components has, so I can experiment...It seems that through changes of this nature, a speaker/XO can be "tuned" in a sense, possibly to even a particular room...Once I understand what parts of the circuit server a particular function, I can experiment on my own...
As you mentioned, the first step will be to ensure I have an airtight seal around the driver and XO panel...I'm hoping to get that accomplished this weekend, as I'm dying to play with my new router!! :)
Thanks again for the immense help!
Quote:
Originally Posted by vuki
Thanks Vuki...The HF section of your XO was built by the gentleman that has been graciously making my other XO's, and he is going to be sending me a pair shortly...He has actually posted in this thread (Donald Patten), and seems to be pleased with the results...
The XO's he's already built have been a significant improvement over the stock XO's, and I really think he's on the verge of a breakthrough XO for these drivers...Perhaps the integration of your circuit topology will be just what's required to get everything situated!
Don actually came to my home, and measured the drivers to accurately calculate the delay between the horn and the woofer, so hopefully some final tweaks to the design will result in the ultimate XO for the 604!
Seadweller:
To get your enclosure resonably airtight you just need to put some form of the gasket between driver/enclosure and crossover panel/enclosure. The easiest way would be to buy window weatherstrip self adhesive tape (anything like this ) and use it as the gasket - it would probably take you less then an hour for both loudspeakers.
I also suggest you to try the crossover as it is posted (it was designed for GPA604-II in a 10cuft.) and then go for the adjustments, if necessary.
Now you're cooking... you couldn't be in better hands.:2thumbsup:Quote:
Originally Posted by Seadweller
I couldn't agree more...Don has a passion for this that is unending, and I'm truly humbled by his generosity...Quote:
Originally Posted by bfish
Thanks Vuki...You'd have to know me to understand my unwillingness to use weatherstrip... :)Quote:
Originally Posted by vuki
Oh no, I'm a perfectionist, so I'll route a channel in the XO panel and press fit a rubber gasket in place... :)
I'm pretty sure the drivers came with neoprene/rubber gaskets, but I'll have to double check to make sure they're in place...
Thanks again, everyone's input is priceless!!
Seadweller
I had to caulk all the inside joints of my Carmel cabs to get rid of the leaks.
The front baffel board leaked the most because the loose weave grill cloth was wrapped around the board with no provison for sealing.
You could try playing a low freq tone, say 30 Hz, and listen and feel for air leaks around the outside of your cabs.
Don
Ok, I confirmed today that there is in fact a rubber gasket on the woofer, so it's sealed tight...The next step is a modify the removable XO panel and install a rubber gasket in that, then I'll test the remainder of the cabinet...Quote:
Originally Posted by vuki
What is the best material for sealing a boxes' removable rear panel and retaining good rigidity? Thin rubber, neoprene, or?
I am finally about to start my MLTL project this week after a couple years of life getting in the way, and this thread has been quite timely.
Hi- back home and reading up. Lots going on.
What's the status? After sealing the (possible) leaks, are you going to try to build Vuki's crossover?
I can also see that tuning the port is going to make a difference. Are you going to do that?
Hi Panomaniac,Quote:
Originally Posted by Panomaniac
Yep, I'm in the process of sealing the leaks...I confirmed that there's a rubber gasket behind the driver, so it's sealed tight...While the cabinet and XO panel mating surfaces were milled to fit tightly, there's no seal, per se, so I'm going to install a gasket of some sort...I'll probably use some weather strip as an interim solution, as recommended by Vuki, and then follow up with a more "professional" looking solution later...
The parts for Vuki's XO have been ordered, and the gentleman that's been building all of my XO's will be assembling a set for me...Hopefully I'll have them in my hands in the next couple of weeks...
He's actually thinking about incorporating the ability to adjust the XO frequency for experimentation, and we're also putting an L-P in place of the 4R7 resistor for ease of adjustment...Once I find that proper value, I may install a fixed resistor...
I'm really hoping that this really accelerates my progress!! :)
And yes, once everything is in place, I'll begin trimming the port tube in 1" increments to see what effect it has on the bass performance....
That's great. Will be interesting to find out how the crossover works out.
Just a general note: I advise against the small 15W L-Pads such as these found at Parts Express. PE L-PAD
They are poorly made. I've had bad luck with any I've used.
Get the 50 watt version. You don't need it for the power, but they are much better constructed.
Thanks for the advice on the L-Pad's...I'll report back in a couple of weeks, as I've got two straight weeks of business travel ahead of me...Quote:
Originally Posted by Panomaniac
:waver:Seadweller,
Any progress with the new crossover?
Regards/Naimare
Well, I have the crossovers, and they're built to Don's usual standards, meaning they're works of art!
It'll take a couple of weeks before I can regroup and get everything hooked up for a meaningful test...Business travel is killing me! :)
:waver: Seadweller
Would be interesting to hear if you had time to compare?
Regards/Naimare
Any update? I have been reading with interest your trials and was wondering if anything developed since April. I hope things have turned out well with all of the work you have put in.
Cheers
Frank M
Thanks for the bump, Frank. Yeah, what's the progress?
I didn't have time to read all the posts in this discussion, so this answer may have already have been stated....
I have owned and listened to many tube amplifiers, and basically I have surmised that the bass sucks in most of them. It's the #1 problem I have by far in getting my systems to sound "good to me". I am currently running 604-8K's in 620 cabs, in one system, and 515B's in 828 cabs in another... the bass should be great in either, not earthshakingly low, but nice punchy midbass... Which is what I want. But unfortunately, about 75% or better of the tube amps I have tried fail miserably. Interestingly enough, the current incarnation of power for the 604-8k's (without mentioning brands) uses wee little el84's run in triode,class A,around 2 watts output, with the preamp using 6dj8 running full out in class A all the time. When I plugged this combo in, it was like I added a subwoofer!
So maybe it's not so much the speakers, but more of an Amp- Preamp problem......
Hope this helps.... Scott
Hi Dooey
As a lover of tube amps and a DIY builder for a few years now, I can understand your disapointment in what your Altecs should be doing.
I can say there is hope... New technuques in Class A SET and PP powersupply design is
on the verge of bringing that sound you want to your Altec systems without use of subs.
( OK along with a little EQ'ing for my taste).
But the fact remains, SET amps can be designed to be full bodied and full range, with dynamics and pace to satisfy the most demanding of listeners. The secret lies in the Simple signal curcuit design and a Superior power supply design all done with quality parts...
I'm there now , a 2 stage 2A3 Triode directly coupled 3 watt amplifier, that can take a 604 or 828 system and drive it to make it bounce, twist, turn, inside out , upside-down or any other trick music can do, and do it with the smoothnest and grace the music deserves.
Today ...this sound is possible you need only seek out the information.
Have fun!
Willie
Not by any means to speak for the man himself of course, but you may look up GM's posts, regarding (paraphrasing) "...period correct high output impedance..." amps. It may provide some insight, per the B's in 828 cabs.Quote:
Originally Posted by dooey263
Advance search for author GM and string 'output impedance' should do the trick.
- may not apply to your newer 604's, but may...
- does not explain the 75%/25% breakdown per se.
Sooner than later I hope to rewire my Almarro to run in SET and see... there's a decware on auction locally, but it's already TRFMB.
I've just spent some time reading the whole 16 pages of this thread & honestly I can't believe what is happening here.
You don't really expect high end, detailed, classic speakers to sound correctly by connecting them to 20 yo Cd players & non descript electronics.
You need to go back to basics here. Double check all your cabinet joints (I seal all the joints in my cabinets with a bead of silicone, regardless of who made them). Your cabinets appear to be very well made & I can't imagine they are contributing to the problems you are having, although I am a little dubious of the downward firing port.
It doesn't matter what your previous speakers sounded like with your current electronics, these Altecs will sound totally different with them.
Beg, borrow or steal some decent electronics, cables & source & you could end up saving yourself a whole lot of heartache.....not that you haven't gone through that already.
And whoever told you that your 20yo Cd player can't affect the sound....don't take any more advice from them.
Sorry to be so blatantly harsh here, but it really riles me that due to others advice you've been through this escapade & nearly sold a classic pair of speakers.
Please, please give them a fair chance to perform.
Remember....garbage in...garbage out.
Good luck.