Cerwin Vega speaker help needed
- Thread starter gagecalman
- Start date
Here's a quote from someone else who has given me some interesting "insight" recently, I have invited him to join in... "One of the best things to improve sound is brace the inside of the cabinets. I have a bunch of old oak hardwood floor boards I use for this. I use PL Polyeurathane and glue in cross braces and 45 degree angles everywhere inside the cabs. Seriously, it makes a big difference. Box resonance really slops up the sound. Get those boxes solid like concrete blocks, and you'll hear the difference!"
That is very true for larger cabs, especially tower speakers. That's why you do see internal bracing in the more "expensive" speakers, and sealed subwoofer enclosures. For smaller speakers though, there is a point of diminishing returns vs the cost of bracing.
7whales7
Addicted Member
The last set of speakers I recapped where some old Jensen's Pr200's I used Dayton Audio (Parts Express) Poly's, expensive and physically larger than the originals....but worth the extra money... They sound great! It's age and heat that kill caps, they don't last forever the values start to drift. Go online and look up how to read your Capacitors value and polarity. There are many less expensive options out there for caps. If your speakers sound good you ....leave them alone, and save some money. I have some Speakers that use Quality Caps originally that I have not changed.
Cerwin Junki
New Member
Hi. This is the guy you were talking to that talked about cabinet bracing. I use scrap oak flooring boards, so other than a tube of PL construction adhesive, bracing doesn't cost anything if you have some scrap wood. I've found it makes a big difference. As to some of the other comments: I agree you shouldn't add a resistor to modify driver impedance. I forget technically why, but I remember reading why and retaining that it won't work properly. I'd have to disagree that the dustcap size effects sound audibly, or effects cooling. I think it's just asthetics. As for driver resistance/impedance, resistance is what you measure with a meter (dc), but that goes up and down quite a bit based on frequency (ac). Impedance is kind of the average resistance the amp sees as it's driving the speaker. Usually measured resistance is about 3/4 of impedance, so if you measure 3 ohms resistance with a meter, it's considered a 4 ohm woofer. If you measure 6, it's an 8. Roughly. On frame sizes, cerwin mostly used the same frame sizes, but not all. There are two different 10" frames, and they were used on two different production runs of the same model woofer. I wish I could remember the model. Also, the new aluminum frames like the xls series are now different (larger) than the older frames (at,vs,ls, etc) As for amps handling lower impedances, mostly agree. However some amps, when using both A and B speakers, internally run them in series. You can tell if yours does this by switching in the B speakers (with no B speakers connected). If your A speakers turn off, it does this. Usually it was cheaper amps/receivers that did this. Doing this does protect the amp, although it also can limit the watts you get out of it. As for securing the T-nuts that fall out of the crumbling particle board. Put the t-nut in place. Then take a screw of the same thread size, coat it with grease, and thread it into the back of the nut a bit from inside the cabinet, then take PL construction adhesive and smear some on the back of the nut. Once it's dry, the greased screws will back out, leaving those t-nuts nicely glued in. And back to amp power, high watt (like over 150 wpc) "home" amplifiers get expensive. It's kind of another world switching to pro amplifiers, like Crown, or Behringer, etc. I still use a Nad for my "best" system, but I use pro amps for my "test" systems, and it's night and day. Pro amps, for the money, are incredible. More power than you can dream of. You can get this kind of amp WAY cheaper. And they are often 2 ohm stable. You have to make sure it accepts rca inputs (many don't, and many do but it's hard to tell because they have a "combination" input jack on the back that doesn't look like a rca jack but accepts an rca to 1/4 jack for unbalanced) The ONLY problem running this kind of amp, is that you're going to start blowing drivers. Really. These things have basically UNLIMITED clean power, and Cerwins will take it and sound amazing right up till PFFFTT! Recone time. Another good amp option are commercial power amps, like Biamp and Bogen. Made for like the ceiling speakers at JC Penny. But these amps are also often cheap (since no one knows what to do with them). Often you have to convert the terminal strip input to rca, but these things are tanks. I have a pair of Bogen 250's. Solid 250 watts, they weigh more than my car and are designed to run flat out full power till the sun burns out. Beefy stuff! Also have a Biamp CPA 650. 325 solid watts per channel, got it for $90. Cerwins do really well with a lot of power. Just be ready to do some reconing, especially if you drink. 
Hi. This is the guy you were talking to that talked about cabinet bracing. I use scrap oak flooring boards, so other than a tube of PL construction adhesive, bracing doesn't cost anything if you have some scrap wood. I've found it makes a big difference. As to some of the other comments: I agree you shouldn't add a resistor to modify driver impedance. I forget technically why, but I remember reading why and retaining that it won't work properly. I'd have to disagree that the dustcap size effects sound audibly, or effects cooling. I think it's just asthetics. As for driver resistance/impedance, resistance is what you measure with a meter (dc), but that goes up and down quite a bit based on frequency (ac). Impedance is kind of the average resistance the amp sees as it's driving the speaker. Usually measured resistance is about 3/4 of impedance, so if you measure 3 ohms resistance with a meter, it's considered a 4 ohm woofer. If you measure 6, it's an 8. Roughly. On frame sizes, cerwin mostly used the same frame sizes, but not all. There are two different 10" frames, and they were used on two different production runs of the same model woofer. I wish I could remember the model. Also, the new aluminum frames like the xls series are now different (larger) than the older frames (at,vs,ls, etc) As for amps handling lower impedances, mostly agree. However some amps, when using both A and B speakers, internally run them in series. You can tell if yours does this by switching in the B speakers (with no B speakers connected). If your A speakers turn off, it does this. Usually it was cheaper amps/receivers that did this. Doing this does protect the amp, although it also can limit the watts you get out of it. As for securing the T-nuts that fall out of the crumbling particle board. Put the t-nut in place. Then take a screw of the same thread size, coat it with grease, and thread it into the back of the nut a bit from inside the cabinet, then take PL construction adhesive and smear some on the back of the nut. Once it's dry, the greased screws will back out, leaving those t-nuts nicely glued in. And back to amp power, high watt (like over 150 wpc) "home" amplifiers get expensive. It's kind of another world switching to pro amplifiers, like Crown, or Behringer, etc. I still use a Nad for my "best" system, but I use pro amps for my "test" systems, and it's night and day. Pro amps, for the money, are incredible. More power than you can dream of. You can get this kind of amp WAY cheaper. And they are often 2 ohm stable. You have to make sure it accepts rca inputs (many don't, and many do but it's hard to tell because they have a "combination" input jack on the back that doesn't look like a rca jack but accepts an rca to 1/4 jack for unbalanced) The ONLY problem running this kind of amp, is that you're going to start blowing drivers. Really. These things have basically UNLIMITED clean power, and Cerwins will take it and sound amazing right up till PFFFTT! Recone time. Another good amp option are commercial power amps, like Biamp and Bogen. Made for like the ceiling speakers at JC Penny. But these amps are also often cheap (since no one knows what to do with them). Often you have to convert the terminal strip input to rca, but these things are tanks. I have a pair of Bogen 250's. Solid 250 watts, they weigh more than my car and are designed to run flat out full power till the sun burns out. Beefy stuff! Also have a Biamp CPA 650. 325 solid watts per channel, got it for $90. Cerwins do really well with a lot of power. Just be ready to do some reconing, especially if you drink.
Thanks CJ, great information to consider! I'm probably not going to get any more power through these than a Pioneer 1010 or Mcintosh MA5100 can put out, for now. I'll probably keep looking for a set of CV L121-4, or (1) L121-4 with a "rib cone" to match the one I have. I like the suggestion forbeefing up the cabs. I also read somewhere that there's a way to deaden the "ring" in the baskets. I want to try that with my steel basket Heppners in the Model 26 cabs I have.
Thanks for the T-nut/glue info, too!
Thanks for the T-nut/glue info, too!
Cerwin Junki
New Member
Hi. I've never seen a ribbed 121-4. I'll bet it was reconed with an ATW-12 kit (for the AT-12). They might have existed, but I've never seen them. You could always get one more and recone them both to match. The L121-4 came in both 4 and 8 ohm versions and you can still get recone kits for either.
I've never tried deadening steel baskets, but it makes sense. It might help, and (with one exception) it can't hurt. Basically you just need to add mass. Whether it's Dynamat, putty, epoxy, or gluing on chunks of car tire rubber. Just one thing, make sure it's on good. Imaging if you were jammin away and a chunk-o-somthin fell inbetween the cone/frame/spider. Ouch!
I've never tried deadening steel baskets, but it makes sense. It might help, and (with one exception) it can't hurt. Basically you just need to add mass. Whether it's Dynamat, putty, epoxy, or gluing on chunks of car tire rubber. Just one thing, make sure it's on good. Imaging if you were jammin away and a chunk-o-somthin fell inbetween the cone/frame/spider. Ouch!
The ATW-12 is a 2" voice coil. It will never work in the L121-4 which is a 1.5" voice coil. So you lost your bet.
That ribbed L121-4 was virgin when I got it a number of years ago. It had what was left of the original CV surround, which is completely different than the foam surrounds you can buy today. Though it is possible it had been reconed at one time, it would have been ages ago.I was planning on looking into deadening with the "Moongel" stuff. I've seen a few drummers use that stuff in their snare drums.
Well I received my "new" midrange FM-6 speakers today, and they are too big. I thought I read somewhere those were used in U123/321 1230???? These holes are 5 1/2" apart cross speaker, I need 4 1/2". Anybody have a suggestion what the correct midrange might be?
Well, now I have probably enough extra speakers to build a set of D5, just in case I find a set of empty cabs.
Well I received my "new" midrange FM-6 speakers today, and they are too big. I thought I read somewhere those were used in U123/321 1230???? These holes are 5 1/2" apart cross speaker, I need 4 1/2". Anybody have a suggestion what the correct midrange might be?
Well, now I have probably enough extra speakers to build a set of D5, just in case I find a set of empty cabs.
Hi. This is the guy you were talking to that talked about cabinet bracing. I use scrap oak flooring boards, so other than a tube of PL construction adhesive, bracing doesn't cost anything if you have some scrap wood. I've found it makes a big difference. As to some of the other comments: I agree you shouldn't add a resistor to modify driver impedance. I forget technically why, but I remember reading why and retaining that it won't work properly. I'd have to disagree that the dustcap size effects sound audibly, or effects cooling. I think it's just asthetics. As for driver resistance/impedance, resistance is what you measure with a meter (dc), but that goes up and down quite a bit based on frequency (ac). Impedance is kind of the average resistance the amp sees as it's driving the speaker. Usually measured resistance is about 3/4 of impedance, so if you measure 3 ohms resistance with a meter, it's considered a 4 ohm woofer. If you measure 6, it's an 8. Roughly. On frame sizes, cerwin mostly used the same frame sizes, but not all. There are two different 10" frames, and they were used on two different production runs of the same model woofer. I wish I could remember the model. Also, the new aluminum frames like the xls series are now different (larger) than the older frames (at,vs,ls, etc) As for amps handling lower impedances, mostly agree. However some amps, when using both A and B speakers, internally run them in series. You can tell if yours does this by switching in the B speakers (with no B speakers connected). If your A speakers turn off, it does this. Usually it was cheaper amps/receivers that did this. Doing this does protect the amp, although it also can limit the watts you get out of it. As for securing the T-nuts that fall out of the crumbling particle board. Put the t-nut in place. Then take a screw of the same thread size, coat it with grease, and thread it into the back of the nut a bit from inside the cabinet, then take PL construction adhesive and smear some on the back of the nut. Once it's dry, the greased screws will back out, leaving those t-nuts nicely glued in. And back to amp power, high watt (like over 150 wpc) "home" amplifiers get expensive. It's kind of another world switching to pro amplifiers, like Crown, or Behringer, etc. I still use a Nad for my "best" system, but I use pro amps for my "test" systems, and it's night and day. Pro amps, for the money, are incredible. More power than you can dream of. You can get this kind of amp WAY cheaper. And they are often 2 ohm stable. You have to make sure it accepts rca inputs (many don't, and many do but it's hard to tell because they have a "combination" input jack on the back that doesn't look like a rca jack but accepts an rca to 1/4 jack for unbalanced) The ONLY problem running this kind of amp, is that you're going to start blowing drivers. Really. These things have basically UNLIMITED clean power, and Cerwins will take it and sound amazing right up till PFFFTT! Recone time. Another good amp option are commercial power amps, like Biamp and Bogen. Made for like the ceiling speakers at JC Penny. But these amps are also often cheap (since no one knows what to do with them). Often you have to convert the terminal strip input to rca, but these things are tanks. I have a pair of Bogen 250's. Solid 250 watts, they weigh more than my car and are designed to run flat out full power till the sun burns out. Beefy stuff! Also have a Biamp CPA 650. 325 solid watts per channel, got it for $90. Cerwins do really well with a lot of power. Just be ready to do some reconing, especially if you drink.
Your assertion of switching A and B speakers to find out how they are wired is utter horse manure. Switching from A to B *will* turn off the A speakers! DuH! Unless someone has (wrongly) rewired the switch. Why in the world do you think there is an "A" *or* "B" selection??? The *only* way to know if A+B <- Got that? A PLUS B, are wired in parallel, or series, is to read the schematic. Or wait for the smoke to escape...
Dust caps do indeed have an influence on the sound. Sometimes virtually no effect, and sometimes a notable difference. Otherwise they would all be the same.. The same with cooling...
Commercial amps, such as PA amps, are not Hi-Fi. There is a huge difference in the quality of sound. I have Bogen amps, and Crown amps and they are nowhere near the quality of sound you get out of Hi-Fi amps. But at a loud party, who cares?
Right? T-nuts don't always fit. But with a little grinding, they hold much better than plastic inserts in particle board.
Not everybody has access to "scrap wood" so they have to purchase some. Just gluing a stick in does help, but properly designed cross-bracing done during construction is the best. And that's why you only see it on more expensive, commercially available speakers. It *costs* more, period.
What you need is what I asked before, is to know the size of the hole they fit in to. The "cutout" size. You could just open the holes up and install them. Just be sure they don't get in the way of the grilles, or get too close to the woofers and tweets.
Whoops, hole cutout is 3 5/8", probably exactly 1" less than needed for the FM6 I just got. I'm going to research the M5 now, I'm going to guess I need the 5" version in these cabs if I want to avoid cutting. So a 1230 (at least mine) has a 5" midrange, not the 6" the U123/321 seem to have (unless that varies, too??).Probably all 1" VC.
OK, I'll measure some mids I have. But they're not "round" (the black CV grilles are), but have a "round-ish" shape with the screw hole "ears".
SO...........
This is probably accurate for my 1230:
High Energy Design Cervin Vega HED U-1230 is a three-way rear-ported tuned bookshelf speaker system with 12-inch cast aluminium frame woofer, 5-inch cone midrange, and 1" inch voice coil horn tweeter; midrange and tweeter level controls.
Spec:
Frequency response 45-17,000 Hz +/- 4 dB;
Crossovers @ 700 and 4000 Hz;
Sensitivity 96 dB/W/m;
Input ranges 5-60 W continuous;
Impedance 8 ohm
Midrange and Tweeter Level Controls
25.5" H x 15.5 W x 11.5 D
37.5 Ibs
Now I just need to know which of the few 5" it is, and I'm guessing FM5, preferrably without the "Made in Taiwan" on the back.
This is probably accurate for my 1230:
High Energy Design Cervin Vega HED U-1230 is a three-way rear-ported tuned bookshelf speaker system with 12-inch cast aluminium frame woofer, 5-inch cone midrange, and 1" inch voice coil horn tweeter; midrange and tweeter level controls.
Spec:
Frequency response 45-17,000 Hz +/- 4 dB;
Crossovers @ 700 and 4000 Hz;
Sensitivity 96 dB/W/m;
Input ranges 5-60 W continuous;
Impedance 8 ohm
Midrange and Tweeter Level Controls
25.5" H x 15.5 W x 11.5 D
37.5 Ibs
Now I just need to know which of the few 5" it is, and I'm guessing FM5, preferrably without the "Made in Taiwan" on the back.