immrridout
New Member
I need some input here folks. I have drawn up the tweeter leg of a 104T crossover with an L-pad in place of the 7.5ohm resister. This would be for b200Y tweeters. Will this work and give satisfactory results? Mick
Beat the Bozak 302 horse
- Thread starter immrridout
- Start date
I found some notes from when we were doing what you're attempting and it did not work. I uploaded a jpg, center of page. The implementation is straightforward: (1) go to (2). Somewhere on AK Retrovert figured out the math and shows exactly what we did wrong and why that mod didn't work. But go ahead and try it. At first you think you kinda did it. But after a bit, you realize something isn't right in Kansas City. That's when we pulled Tobins work out altogether. The 8uf cap and the L-pad is all you need. The less crap in your signal path is best.
Biggles
Biggles
Attachments
Found it, the reason why. July 25, 2019 in this post by Retrovert.
Bozak B-300 Urban's to 302's
Hey mang, I found that when I used the stock configuration for a single woofer Symphony it was a success. This is having the woofer mounted in the upper hole, the bottom cutout has a cover. I thought it'd mess with my low end, but it didn't. I wouldn't bother making a new baffle. And all...
audiokarma.org
immrridout
New Member
I ran across something and I would like to tell everyone who might be interested, but I cannot figure out where to post it. So I will just post it here and maybe it will get around.
Has anyone noticed that there is a single Bozak 302 listed on Ebay. It actually looks pretty nice. He has it listed for $179, but he sent me an offer for $100. I would certainly get it, but it is local pick up only in West Mifflin, Pennsylvania and I am in Texas. I'll be he will take the first $100 offer that comes along. Any of you guys up there might want to check it out. Mick
Has anyone noticed that there is a single Bozak 302 listed on Ebay. It actually looks pretty nice. He has it listed for $179, but he sent me an offer for $100. I would certainly get it, but it is local pick up only in West Mifflin, Pennsylvania and I am in Texas. I'll be he will take the first $100 offer that comes along. Any of you guys up there might want to check it out. Mick
immrridout
New Member
immrridout
New Member
I'm curious about what people do with their new found Bozak 302's. I am not really hearing about a definative upgrade. Once you change the woofer from 800 to 400 hertz and put in all new caps, What is the accepted thing to do with the crossovers. I get the impression that my idea of using an l-pad in the tweeter section is out in left field. I would like to see a schematic drawing of what is now the preferred crossover upgrades. Does anyone put in an L-pad? Are there any changes of caps, or does everyone just stick with the factory layout. I'm not interested in experimenting with lots of options. Tell me what makes the best sound, show me the schematic and I will do it that way. Mick
Hey Mick,
One of the many reasons Bozak owners chose Bozaks is that it's okay to experiment, modify, change any damn thing you want to. So, we've tried all kinds of things. Some worked out, some not so well. Which is why I, or we come by here to impart what we've learned with others. If you do a week or two worth of research here on AK, member Twiiii (not sure how many it's) has done some fancy stuff with his massive Bozaks and electronic crossovers. Others have tried second order crossovers, but didn't like the results. Rudy's drivers prefer simple first order. You could try crossing the woofer and a B209b over at 200hz. But I'm not sure how well the 209b would handle that. Most now run woofer mid at 400, Tobin cut mid at 1250, tweeter comes in at 2500. Tweeter with just a 8uf cap and the L-pad. The latest upgrade is the Morel tweeter addition. But that's a pricey one.
One of my personal favorite ideas, one I never got to, was a 302a, with the B800 driver instead of the B209b. Its an Bozak 8" aluminum cone midrange. Now THAT will go down to 200hz! I built my own Bozak Symphonys from parts and used the ultra rare B800A mids. Hands down one of the finest mids ever made. Lush, deep, detail like you've never experienced in your life.
One of my secret crossover upgrades is I've been buying Mundorf Electrolytic caps from Willys Hi-Fi Ltd out of the UK. Some now have the Jantzen name on them. Fine German caps meant for audio.
I've attached a jpg of the crossovers I used to build and sell. This was years ago when the Tobin mod was still a thing. Later it got removed and I added the L-pad instead.
Another crossover mod you can do, that I do with most all of mine is to run my crossovers externally. Buy a 3 way binding post wall plate, mount on the backs of your cabin. Mount the crossover on the backs of your cabinet or set on the tops. Easy access for changes, different caps.
Biggles
One of the many reasons Bozak owners chose Bozaks is that it's okay to experiment, modify, change any damn thing you want to. So, we've tried all kinds of things. Some worked out, some not so well. Which is why I, or we come by here to impart what we've learned with others. If you do a week or two worth of research here on AK, member Twiiii (not sure how many it's) has done some fancy stuff with his massive Bozaks and electronic crossovers. Others have tried second order crossovers, but didn't like the results. Rudy's drivers prefer simple first order. You could try crossing the woofer and a B209b over at 200hz. But I'm not sure how well the 209b would handle that. Most now run woofer mid at 400, Tobin cut mid at 1250, tweeter comes in at 2500. Tweeter with just a 8uf cap and the L-pad. The latest upgrade is the Morel tweeter addition. But that's a pricey one.
One of my personal favorite ideas, one I never got to, was a 302a, with the B800 driver instead of the B209b. Its an Bozak 8" aluminum cone midrange. Now THAT will go down to 200hz! I built my own Bozak Symphonys from parts and used the ultra rare B800A mids. Hands down one of the finest mids ever made. Lush, deep, detail like you've never experienced in your life.
One of my secret crossover upgrades is I've been buying Mundorf Electrolytic caps from Willys Hi-Fi Ltd out of the UK. Some now have the Jantzen name on them. Fine German caps meant for audio.
I've attached a jpg of the crossovers I used to build and sell. This was years ago when the Tobin mod was still a thing. Later it got removed and I added the L-pad instead.
Another crossover mod you can do, that I do with most all of mine is to run my crossovers externally. Buy a 3 way binding post wall plate, mount on the backs of your cabin. Mount the crossover on the backs of your cabinet or set on the tops. Easy access for changes, different caps.
Biggles
Attachments
immrridout
New Member
Thank you very much. I am pretty sure what I will do now. And it's pretty simple. All this is much clearer to me now. I expected others to chime in on these speakers. I am glad that you commented on all my questioning. I would have really been in the dark otherwise. BTW, on Facebook, I did get some info, but mostly a reference for me to get in touch with DrBiggles on AudioKarma. He's the man. Ha. Mick
immrridout
New Member
One other thing. I am as interested in maintaining the original MCM allure and quality. With that in mind, unless I can't do it any other way, I would keep the original components. The B200Y tweeters will look the same but be an improvement. I will re-cap into the original metal housing on those beautiful crossovers. Back in the sixties, I lusted after AR and KLH even though the crossovers were a piece of masonite with the caps glued down on it. These are cosmetically so much better. Even though no one will ever see them, I will know and enjoy that they are there. I want my cabinets to ooze MCM. It's part of the allure. Mick
twiiii
Lunatic Member
When Bozak went from the earlier 199's to the later 199 design the speakers were able to handle more power. 18 watts RMS 24/7 to 25 watts RMS. I drive my spekers, Concert grands tri amped. one channel for the woofers, another channel for the mid/tweeters using a N-107 passive crossover, and another channel for the tweeters. When the stereo system was tubed in was 275's, then to 2100's and a 250 when I added the super tweeters. Then to Crown DC 300'A's and a a D-150 A, then to PS2A, for the woofers. But sound was a bit on the austere side. So I went back to Mcintosh when they released there first direct coupled amps. two 7200's and then a 7100 for the super tweeters. When we up dated the system in the Early 2000's to a HT set up adding 3 4005 symphony speakers and two B-313's we changed to two MC 207 power amps.
I never seem to use more than 50 to 60 watts a channel for the front speakers and maybe 5 to 8 watts for the rear and sides.
Bozak speakers have pretty much the same sensitivity give or take a few DB. So matching woofers to midrange is very easy. I prefer either a 250 HZ crossoveer to 400 HZ crossover between the woofer and midrange and as the mids are already operated with the polarity reversed using a second or 3 rd ordered crossover makes the change easy and protects the mids. Adding super tweeters is for the young and most old guys wont hear the difference. Bozak Y tweeters can use a Tobin mod to fool the ear into thinking there are better highs when there aren't. Ceramic Bozaks have a clearer cleaner sound, which some like and other find less musical. I really don't like the ceramic midranges, but thats me. I bi amp my woofers to improve the transients and clean up some of the midbass which can really color the sound unless you voice your speakers or pull them away from the wall a bit. But if you do pull them
away you can loose any where between a half octave to 2/3 of an octave on the bottom end. Z tweeters use a different crossover set up and are flat to above 17.5 KHZ so a Tobin mod is not necessary. I chose to add super tweeters by Celestion way before the Z tweeters came along and preferred the result so I never changed from Y tweeters to Z tweeters. If you use the 8 tweeters in a line array then you should be good to go with any amp up to 150 watts or so as long as you don't clip the amp. Same goes if you have two mids. 4 woofers can take a bit more peak power. I have never lost a driver due to to much power with my Grands or Symphony Speakers. I currently use amps that can put out 250 watts per channel 24/7. But seldom see peaks of 100 watts. most of the time its around 20 to 30 watt peaks with 2 to 5 watt averages.
I don't care how many woofers you have if you want more extended bass you need a larger enclosure. I installed a few Symphony panels that backed into a closet or garage and the easily reached 25 hz. Concert Grands below 20 HZ. My Grands reach down to 23 HZ with a 3 to 4 db boost at 25 hz but a rapid roll off below that. I'm using a half octave parametric EQ with 10 bands for the Grands and Symphonies. My stereo system I use a parametric with 1/3 octave filters with Mcintosh speakers that are line arrays which are an advancement over the Symphony design that Roger Russell used as an inspiration.
There is a Bozak Group on Facebook you can join that has a wealth of information with diagrams and schematics on how to improve and get the best out of your Bozaks.
Only the 302's and smaller 313, 501 and 312 are point source speakers and can be listened to with relatively close listening distance of less thn 10 feet. Larger models you have to sit back further to allow the drivers coverage patterns to integrate properly. I prefer 16 to 20 feet for Grands with the line array and Symphony speakers with the line array. The 4005 with the spherical array and the 310 grands with the spherical arry if they have one midrange you can move slightly closer toward the speakers. The big mistake I see with Grands is the mids should have been stacked vertically and placed adjacent to each other to prevent beaming which is common with Grands with the mids placed side by side. I pefer Grands with the line array of tweeters in the middle as they integrate better with the two mids on either side close by. I prefer Symphony speakers with the line array on the side so you can choose how wide of a sound field you want. I preferred my Symphony speakers spread further apart with the tweeters being on the inside. This image was taken in 64 or 5. And, Yes, there is a 302 load in the TV speaker enclosure used as a center channel.
power by the MC 60. .
I never seem to use more than 50 to 60 watts a channel for the front speakers and maybe 5 to 8 watts for the rear and sides.
Bozak speakers have pretty much the same sensitivity give or take a few DB. So matching woofers to midrange is very easy. I prefer either a 250 HZ crossoveer to 400 HZ crossover between the woofer and midrange and as the mids are already operated with the polarity reversed using a second or 3 rd ordered crossover makes the change easy and protects the mids. Adding super tweeters is for the young and most old guys wont hear the difference. Bozak Y tweeters can use a Tobin mod to fool the ear into thinking there are better highs when there aren't. Ceramic Bozaks have a clearer cleaner sound, which some like and other find less musical. I really don't like the ceramic midranges, but thats me. I bi amp my woofers to improve the transients and clean up some of the midbass which can really color the sound unless you voice your speakers or pull them away from the wall a bit. But if you do pull them
away you can loose any where between a half octave to 2/3 of an octave on the bottom end. Z tweeters use a different crossover set up and are flat to above 17.5 KHZ so a Tobin mod is not necessary. I chose to add super tweeters by Celestion way before the Z tweeters came along and preferred the result so I never changed from Y tweeters to Z tweeters. If you use the 8 tweeters in a line array then you should be good to go with any amp up to 150 watts or so as long as you don't clip the amp. Same goes if you have two mids. 4 woofers can take a bit more peak power. I have never lost a driver due to to much power with my Grands or Symphony Speakers. I currently use amps that can put out 250 watts per channel 24/7. But seldom see peaks of 100 watts. most of the time its around 20 to 30 watt peaks with 2 to 5 watt averages.
I don't care how many woofers you have if you want more extended bass you need a larger enclosure. I installed a few Symphony panels that backed into a closet or garage and the easily reached 25 hz. Concert Grands below 20 HZ. My Grands reach down to 23 HZ with a 3 to 4 db boost at 25 hz but a rapid roll off below that. I'm using a half octave parametric EQ with 10 bands for the Grands and Symphonies. My stereo system I use a parametric with 1/3 octave filters with Mcintosh speakers that are line arrays which are an advancement over the Symphony design that Roger Russell used as an inspiration.
There is a Bozak Group on Facebook you can join that has a wealth of information with diagrams and schematics on how to improve and get the best out of your Bozaks.
Only the 302's and smaller 313, 501 and 312 are point source speakers and can be listened to with relatively close listening distance of less thn 10 feet. Larger models you have to sit back further to allow the drivers coverage patterns to integrate properly. I prefer 16 to 20 feet for Grands with the line array and Symphony speakers with the line array. The 4005 with the spherical array and the 310 grands with the spherical arry if they have one midrange you can move slightly closer toward the speakers. The big mistake I see with Grands is the mids should have been stacked vertically and placed adjacent to each other to prevent beaming which is common with Grands with the mids placed side by side. I pefer Grands with the line array of tweeters in the middle as they integrate better with the two mids on either side close by. I prefer Symphony speakers with the line array on the side so you can choose how wide of a sound field you want. I preferred my Symphony speakers spread further apart with the tweeters being on the inside. This image was taken in 64 or 5. And, Yes, there is a 302 load in the TV speaker enclosure used as a center channel.
power by the MC 60. .
Last edited:
Mick,
Heres a couple 302a's that I did years ago. Professionally built by a cabinet maker in the late 1950's or early 1960's I think. They were a mess when I got them. I used the existing cloth, maple top, and they had the 1960s drivers. Refinished the top, new maple edge banding, new maple trim top and bottom with new wood legs. Fiberglass removed, cotton batting with swinging curtain installed. Mid properly covered. Custom, proper Bozak 3way crossovers with bypass caps. Those damn things sound like a bloody finely tune surgical instrument of sound. Still, to this day I've not heard a pair of Bozaks beat these. Musical superiority. From Bach to Rammstein, they'll wear you the hell out and take you down town for ice cream.
Biggles
Attachments
Those look familiar...
Yes I know. Look closely at my avatar.
Huh, well ain't that something. They're IN YOUR LIVING ROOM MR. BERGER!!!! Ha! Gotta keep them in the family.
Biggles