High Efficiency Speaker Asylum

Need speakers that can rock with just one watt? You found da place.

Return to High Efficiency Speaker Asylum

Message Sort: Post Order or Asylum Reverse Threaded

My GPA 902's came in today....

68.8.134.175
Posted on July 24, 2015 at 17:36:41
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 Wow, that was fast. I ordered them on Tuesday and when I got home today they were sitting on the porch. Unpacked them and Hooked them up so now they are breaking in. Now I have to get to work on Zilch's Z19 Xover!

The build quality of the GPA 902's is top notch and some heavy suckers too. Way bigger than the Dayton D250P's.

I want to say a big Thank You to Bill over at Great Plains Audio for all his help and the fast shipping!

Now I will start saving up for the GPA 416 woofer.

thanks everyone!

 

Hide full thread outline!
    ...
20 hours of break in..., posted on July 26, 2015 at 13:33:53
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 and my GPA 902's are starting sound really nice. I know I still have a long ways to go but just wanted to post what is going on so far. This is with that same 1st order Xover that was @ 1.5Khz.

One thing I did notice right off the bat was how nicely the GPA 902's were on Sax, Piano, and guitars. There was more weight or thickness that made those instruments sound more real that on the Dayton D250P. I'm also hearing better bass notes now that before. I have just been having them as background music and at times I hear some tunes when there is a solo and I have to look over cause the sound is so nice that is grabs my attention.

I almost finished with the Z19 Xover which will be in a rough prototype, I'm in a hurry and see how it works with these GPA 902's, QSC horn, and the MCM 55-1880 woofers. I will be working on the finished Xover while this prototype is breaking in.

I will soon be ordering the GPA 416-8C woofers and then I should have something really special.

BTW, I noticed the GPA 902's have this braided mess over the exit hole. I don't remember my Altec Model 14's with 902's having this. If I'm remember correctly they had a black material across the exit/opening when I would look in there but I never took the drivers from off the horns. Has anyone removed this and what were the results?

So far it doesn't seem to affect the sound, it nice a clear with good reverb and depth to them.

 

RE: My GPA 902's came in today...., posted on July 26, 2015 at 16:18:03
PaulF70
Audiophile

Posts: 1423
Location: Midwest
Joined: June 30, 2006
 I don't know what the 902 is but I'e been enjoying my 604s on JE Labs baffles for a long time. I recently switched back to them. The best hi-eff driver in existence IMO for any kind of sane money.

 

RE: My GPA 902's came in today...., posted on July 26, 2015 at 16:38:54
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 The GPA 902's are a compression driver.

I was going to buy the GPA 604's a few years back but got side tracked. The GPA 604's may still be an option if this project doesn't work out but so far I'm liking what I'm hearing.

I just finished the Z19 xovers about an hour ago. So now it's breaking in along with the 902's

I've heard a lot about the 604's but I have never heard one in person yet. :(

 

RE: My GPA 902's came in today...., posted on July 28, 2015 at 08:00:18
geezerrocket



I bought the Alnico version (802-G) from Bill and love them.





 

RE: GPA 802, posted on July 28, 2015 at 08:51:12
deathtube 667
 What sort of crossover do you use with those GPA 802's and how far does the bandwidth extend in your listening room?

The 808-8A's I have are limited bandwidth, so a 2 way system is not really possible with those.

Been thinking about the GPA 802 or 902's as a upgrade.

 

RE: GPA 802, posted on July 28, 2015 at 12:30:51
geezerrocket
 I use a ALK ES-700 crossover.
The ALK is for Al Klappenburger, the ES is for extreme slope, the 700 is for 700 hz between the woofer and mid driver.

This crossover allows you to run them 2 or 3 way. It also allows you to boost the mid/tweeter (802-8g) if you wish. I like them both 2 and 3 way.

Go to the Web site linked, in the left column click on Klipsch upgrades (they are for Altecs as well), then extreme slope.

I chose the alnico (802-8g) over the ferrite (902), because I think there is a certain synergy between alnico magnets and tubes -but that's me. YMMV......


Good luck.












 

Me too, posted on July 30, 2015 at 14:25:27
Paully
Audiophile

Posts: 5909
Location: West Virginia
Joined: February 15, 2004
 Put Alnico GPA drivers in some vintage Altec Model 19 cabinets and built the Zilch 19 crossovers. Good stuff.

 

RE: how's the top end on the 902's?, posted on August 1, 2015 at 06:31:13
deathtube 667
 Do you like the high end on those 902'S?

No issues going full range with a 2 way setup?

I went back to the D250P in my system and I actually like how they sound crossing over at 1500 cycles up. Using 414-8B below the horn.

With some EQ, the top end is extended unlike the 808-8A with aftermarket titanium diaphragms. Still debating if GPA diaphragms would help those, but Bill did tell me that those drivers don't have much output beyond 10KHz.

If I would have been wise, I would have got the GPA 902 or 802-8G instead of that vintage Altec driver for a 2 way system.



 

Love the sound of the GPA 902's, posted on August 1, 2015 at 20:58:05
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 they have the sound I remember when I had my Altec Model 14's which had 902's in it. The difference that I have noticed is that the top end on the GPA 902's is more extended. The D250P were nice but didn't have that weight or meat in the midrange once compared to the GPA 902's had to give it that more like it's real/right here. The 902's were more real/lifelike.

The Dayton D250P sound really nice with a 1st order Xover with good caps. I never got around to trying a 2nd order Xover.

the GPA 902's with the Zilch's Z19 are just amazing. I really like this Xover. You can do so much with it. I highly recommend it with the GPA 902's. At first I thought the Z19 had a slight lightness to it but once I figured out how to set the Z19 I got that Altec sound back but with extended upper end. With that great midrange where vocals, strings, and horns sounds so real.

I'm really glad I bought the GPA 902's. The best thing I can say is that the GPA 902's are a step up from the original Altec 902's. They just built up on top of what Altec already had done but just took it to the next level up. :)

If you search you will find a econowave Xover that is designed for the Dayton D250P with QSC horn. I think it uses a Eminence woofer or Dayton 380 woofer. might be something to check out.

I think the GPA 902 would be a better match with those 414-8b.

I will be saving up for some GPA 416-8C's!

Also, remember the GPA 902's can be xovered down to 500hz with a Altec 511b horn. but Bill at GPA told me sounds best Xover at 1200hz. I agree!:)

Hope this helps.

 

RE: Love the sound of the GPA 902's, posted on August 2, 2015 at 12:08:33
deathtube 667
 Thanks for the report.

FWIW, I picked up a set of Dayton H812 horns to go with the D250P's.

They seem to be a better match for the D250P's than the 811B's , they sound really smooth.

I'm giving the 808's one last chance with a new set of aluminum diaphragm said to be similar to Altecs.

Not sure if removing the black plastic loading caps can improve the highs or not, I have read conflicting reports.

If that does not satisfy, then I will consider the GPA drivers or others.


 

You hould try the GPA or Radian, posted on August 2, 2015 at 15:02:00
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 replacement diaphragms. What brand are these replacements? No name After market diaphragms may not be the best for the Altec 808.

Hope you can get them to work like how you want.

 

RE: Love the sound of the GPA 902's, posted on August 3, 2015 at 07:41:34
Hornlover
Manufacturer

Posts: 2529
Joined: March 8, 2002
 I remember reading at one time that the 80X series of drivers were designed to roll off above 8k. They were designed for sound reproduction in movie theaters, and the optical sound tracks had no information above that. They designed them to roll off to reduce the noise above the optical tracks upper limit.

 

RE: Love the sound of the GPA 902's, posted on August 3, 2015 at 08:32:02
deathtube 667
 Bill at GPA told me the same thing.

Mine are dropping out a lot sooner in room, but I need to take some on-axis measurements to get a better idea.

If I could find a solution for the top octave, then I would probably be ok with the 808's.

 

Another route you can take is..., posted on August 3, 2015 at 18:46:03
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 use the 808's but add the Beyma CP25 Bi-radial horn that will cover the rest of the upper end. They say these match well with the Altecs and JBL's.

But if a true 2 way is what you want then maybe the 902's are the way to go!

 

RE: Another route you can take is..., posted on August 3, 2015 at 23:46:37
deathtube 667
 Yeah, it seems like a few people are using the Beyma tweeters.

PE also as a lot of high efficiency compression drivers, perhaps one of those and a small horn lens would be OK.

Or I could see how the H812/D250P works as a tweeter before laying out any more cash.

 

RE: Another route you can take is..., posted on August 4, 2015 at 23:25:27
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 The Daytons are nice sounding but I did experience something when I was evaluating those drivers. I was playing some Diana Krall and during the guitar solo I heard some break up from the guitar. At first I was like "wow, never heard that before" and thought the driver was just picking up something from the recording of the guitar amp breaking up. When I turn the volume down, the break up went away.

After I received the GPA 902's, I went back to the same recording and that break up was not there. So it turned out to be the Dayton D250P. This was Xover @ 1.5Khz so it should have been well within it's range of operation. This was a 1st order Xover that I was using with it. It could be that some compensation or different xover point could have fixed this. Other than that, I was happy with the sound of Dayton D250P just a thinner sounding CD compared to the GPA 902's.

 

Finally finished one of the Z19 Xovers., posted on August 11, 2015 at 20:32:24
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001



I still need to finish the box for this one and add the L-Pads. I will start on the other Xover for the other side.

 

RE: 20 hours of break in..., posted on September 15, 2015 at 18:29:19
Glenhorn
Audiophile

Posts: 2
Location: Minnesota
Joined: September 15, 2015
 "BTW, I noticed the GPA 902's have this braided mess over the exit hole. I don't remember my Altec Model 14's with 902's having this. If I'm remember correctly they had a black material across the exit/opening when I would look in there but I never took the drivers from off the horns. Has anyone removed this and what were the results?"

It sounds like you're talking about the bug screen on the exit hole that seem to come with all compression drivers. I read somewhere where someone claimed those screens can cause some sort of distortion and thus should be removed for home indoor use. I took the screens off as soon as I got my Selenium D250X drivers and I love the sound from them but I never did any A/B test comparing them with the screens on. But it was easy to take the screens off using needle nose pliers.

 

RE: 20 hours of break in..., posted on September 15, 2015 at 19:19:04
Glenhorn
Audiophile

Posts: 2
Location: Minnesota
Joined: September 15, 2015
 Edit to add: I have a pair of old Altec alnico drivers, 802-8d I think, that need work and are in storage. But back when they were working I left the bug screens on and they sounded great. In fact, it was those drivers attached to the 511b horns that got me hooked on horn loaded speakers.

 

RE: 20 hours of break in..., posted on September 20, 2015 at 08:06:07
Cougar
Audiophile

Posts: 4590
Location: SoCal
Joined: June 25, 2001
 "It sounds like you're talking about the bug screen on the exit hole that seem to come with all compression drivers. I read somewhere where someone claimed those screens can cause some sort of distortion and thus should be removed for home indoor use. I took the screens off as soon as I got my Selenium D250X drivers and I love the sound from them but I never did any A/B test comparing them with the screens on. But it was easy to take the screens off using needle nose pliers."

Glenhorn, Thank You for the replay. Sorry for the late reply, I just saw this post.

This braided mess looking screen is different from other screens i have seen on my Dayton's and on other CD drivers. My 902's sound good with them on but I will check with Bill @ GPA about removing them. I just wonder how much difference if any this will make in sound quality.

Thanks.

 

Page processed in 0.031 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]