Bonder

Crash Test Dummies and my personal fav: Beat Farmers

Check that auction site for current prices on the SX 1250, the SX 5590 is very difficult to find given the number produced. There's a number of folks who would be willing to pay a premium over a SX-1250. The SX 1250 can sell from $500 to over $1,000 depending on condition. Alot of hardcore Pioneer experts feel the SX-1250 / SX - 5590 were the best receivers ever produced by Pioneer.

Absolutely nothing special about those, first time bidder, perhaps he/she got carried away? or it's simply a bogus buy.

This is just my opinion (everyone's got one)[] I'd change the caps on only one crossover to start and see if you can hear any difference by comparing with the other. At minimum this will give you a reference to the improvement the new caps will have. I've modded my Cornies a fair amount and for me the most noticeble improvement was changing the tweeter, if I have started with the tweeter change I may not have done anything else. Good luck

Seti, The rat shack SPL meter is pretty unreliable over 10,000 so my curves wouldn't be useful, I'm pretty sure I'll need to get a RTA to figure this out. Overall I'm happy with the 902, it's a great driver for it's price point. If I can't get it to get down to 500 hz then I'll just leave it and enjoy the music.

Thanks for your input Larry, I certainly need better testing equipment to validate what I'm seeing, perhaps the rat shack meter is off and I'm actually at or around 500 hz before it dives. I agree 600 hz is a preferred low end, just can't get my bass bins to reach that high. Good to hear your happy with a two way set up, I've tried this with my Cornwalls and with some music I thought I was missing some sparkle, I'm bringing the Beyma's in high and they do seem to integrate well to the point I'm very happy with the mid and top end. I have a K51 from my Cornwalls I could try to validate my readings at 500 hz, good suggestion, it's worth a try, thanks again.

Hi Terry, I haven't heard any buzzing or distortion at 90 - 95 db levels while listening to music, I don't want to play it any louder in my garage out of respect for my neighbors. My bigger concern at this time is whether the driver actually goes down to 500 hz, it seems to go down to about 750 hz but then takes a big dive. When you were running 3 way do you recall what size of cap you were running before your autotransformer (and the tap you were running to the mid). Overall it sounds very good, perhaps I'm getting too caught up in the numbers/measurements... occupational hazard being an accountant [] Thanks, Shayne

Been tinkering with the Sentry bass bins and crossover to my 902/CP25 combo. DJK: While the article states usable output to 850 HZ there's not much more than 550 hz before it starts to take a nose dive, I started with a 2.5 mH inductor but removed that to squeak a few more db's out. The 902 driver is another story, can't get it low enough to meet the bass bin at 500 hz, best I can do is about 750 hz(I started a new thread to see if there's anything I can do to get it to reach down any more). If possible I'd like to correct this even though I'm not sure I can hear this dip. I've played 90% test tones this week so I can't comment on the sound in detail, further listening is required. First impressions are good, the speakers are in the garage so I'm going to move them to the man cave after I'm back from vacation. Will report back in a few weeks.

Hello all, I'm an infrequent poster on the forum (but an avid reader!), I'm hoping someone can point me in the right direction with regards to my issue. I'm building new 1st order crossovers (similiar to a B-1 network) for my new Speaker project: EV Sentry IV bass bins crossed to a Altec 511B / GPA 902 mid driver and then a Beyma CP 25 tweeter. I'm trying to cross the Bass bins as high as possible which in this case looks to be 500 hz as the bass bins are down 8 db at 630 hz, my problem lies with crossing the GPA 902 driver (8 ohn version) at 500 hz, it just doesn't seem to want to reach that low. The Beyma is being crossed above 9- 10,000, I'm just letting the 902 run out as it starts to tail off over 12,000 (Edit, this likely isn't accurate as my meter isn't reliable over 10,000, in any event I'm very happy with the mid to tweet crossover, very smooth and integrated) I've read numerous posts about forum members crossing this driver as low as 400 hz, however it's not clear to me how they're doing this, I've tried a number of capacitor values (8 uf, 10 uf, 14 uf) and even ran them without caps (low levels) and am getting consistent results that say the driver won't go lower than 700 - 800 hz before it takes a dive. Additional background that likely is contributing to my problems: 1. I'm using a rat shack spl meter with a correction table 2. I'm assuming the reflected impedance to the Autotransformer (3636) is approximately 26 ohms (4 X the impedance of the driver) 4. Measurements are being taken 7 feet from speaker at listening positon in my Garage (24 ft x 24 ft), 3. I'm a noob when it comes to electronics Here's a table of my measurements GPA 902 (8 Ohm) - Reflected impedance ~ 26 Ohms (Taps 5/3 on 3636 Autotransfo rmer) DB's HZ 8uf 10 uf 14 uf No Cap 250 54 54 54 54 315 55 57 59 60 400 61 64 67 68 500 60 62 66 66 630 68 68 67 68 800 78 78 78 78 1000 80 80 80 80 Anything in the above surprising? For those running 902's are you getting stronger results at 500 hz? Again I'm not even trying to get to 400 hz, I'd be happy with 500 hz. All suggestions / comments welcome, thanks in advance!

Thanks for the update, I'm going to have some time next week to tinker with mine, I'm hoping the bass bin will reach up to 500 hz. Will share my findings once I've get them in sync. Bonder

Wrinkles, I purchased a pair of Sentry IV bass bins a month ago, I've had been searching for a pair for a number of years. I've refoamed 3 of the woofers and have sourced a reconed 4th that will be delivered over the next week or so. I'm going to slap my Altec 511/902 on top and give them a test drive shortly. I have fond memories of these speakers when I last heard them in 1980, very punchy, clear and loud, perfect for Rock and Roll. I'd be interested in your impressions as well as any crossover work you're doing to accomodate the K402s, I believe the Sentry IV crosses the midrange at 400HZ and the tweeter at 3500HZ Bonder

Last year I took my family on a camping trip to the Canadian Rockies.. On our way there we stayed / camped in Drumheller Alberta where they have an amazing Dinosaur museum. The campsite we stayed was very unremarkable except for their "Mobile Fire Pits"... one part Washing machine and one part lawn mower.... I still chuckle when I see this picture...[]

On Monday I saw: Lyle Lovett, John Hiatt, Joe Ely and Guy Clark perform their final show of a 40 city tour.... just 4 guys on stage with their acoustic guitars, no set lists, no attitudes, just 2+ hours of great music[Y]

"Could be an inadequacy in the amplifier as well. " Can you elaborate? I don't understand how an amplifier could contribute to a room node issue.... Thanks!

BG, I have a modest sub (Monitor Audio FB 210) running with my CW's to fix a big suck out from 40 - 90 HZ in my room... with the Sub on (and CW's set to large) I'm getting a flat response between 30 - 100 HZ. Some day I'll build some bass traps to try and fix the problem... I still might keep the sub connected as I'm a bit of a basshead.[]

Shawn, I'm interested in the 2404 tweets, will send a PM Shayne,

Thanks for the feedback Shawn, appreciate the comments.... I have 511B's I'm using so I'm going to give those a try with the 902's.... if and when I try a K510 I'll look for a different driver [Y]

That's a scary set up there Shawn (in a good way)!! I can almost feel my chest compress just looking at those subs... So how does the 902 compare? I've been trying to buy a pair of 902's on E-bay for the last month and keep getting shut out.... perhaps there's something better or easier to score?

Revjac, Just to give you some perspective from a fellow Canuck... I purchased my 82 Cornwalls (K51V driver and B-2 Network) less than a year ago for $750 Cdn from a local high end Hi fi shop ... they had been listed for $1,400 then reduced to $1,000... that's when I jumped on them. My speakers were in very good condition... 8.75 to 9.00 out of 10. Bring lots of your music and put them thru a good demo... Good Luck!!

You might also want to consider: Buddy Guy Stevie Ray Vaughan Keb Mo Johnny Winter Jimmy Thackery

I'd recommend Linda Ronstadt's Simple Dreams... not saying she's the best but she has quite the voice and the sound quality of the CD is quite good! Had a big crush on her in Junior High...

"Breaking Silence" by Janis Ian.... the production on this CD is impecable from the first to last cut... If only all artists demanded this type of sonic perfection for their recordings!!

My top 10: 1. Live with me 2. Miss You 3. Cant you hear me Knocking 4. You got the Silver 5. Country Honk 6. Brown Sugar 7. Dead Flowers 8. You Cant always get what you want 9. Its only Rock and Roll 10. Gimmie Shelter 5 of my top 10 come from Let it Bleed....hmmm best Stones Album IMHO...

Pioneer's biggest receiver was the SX-1980 rated at 270 wpc, this was the totl model from 1978 thru 80. This is typically the most expensive of the vintage pioneer receivers on e-bay. However, many Pioneer collectors feel the SX-1250 (totl model from 1976 thru 78) was the better sounding receiver, it's rated for 160 wpc and typically sells for much less than the SX-1980 (assuming similiar condition, etc). I have a SX-5580 (Black euro version of the SX-1050) rated at 120 wpc... it's more than enough for me...although I wouldn't pass on either of the above models if the price was right.[]

I've been fortunate to find 3 nice pieces at a couple of garage sales within the past 3 weeks (all within 1 mile of my home). Sony STR 6055 receiver (condition 9.5 / 10) Pioneer SX 650 receiver (condition 9.5 / 10) Pioneer PL 117D turntable (condition 9 / 10) All pieces were purchased from their original owners who obviously took care of them. None of these were totl but considering I paid a total of $50.00 I think I did pretty good... unfortunately now that winter is almost here I'll have to wait 7 months before I can see if my luck continues... it's always a hit or miss at garage sales.