Why do my 288-8Ks sound like cr@p?

[Coendert2011]

Hello Coen,

Well, more than 4 months have passed , so;

I'm wondering if you have any updates to share with us about your 288/511E setup ?

Did you receive those GPA diaphragms ( # 23763 ?? ) that you ordered & did you load them up & measure their performance ( etc. ) ?

Did you go back to listening to the 802/511 as your primary setup ? ( if so , why ? / if you don't mind me asking )



cheers <> EarlK

Hi Earl,

Thanks for the interest.
I have been very busy with my family during the summertime and left this project for rainy autumn and winter nights!

Being so busy I did not pay enough attention to an important lack. As a matter of fact I never received the GPA replacement diaphragms.
Worse, while slipping my attention repetetively, I did leave a few track and trace requests by mail at GPA without any reply. I planned to post about that in this forum.

I am really surprised about this since the service has been excellent so far.

Anyway, I made a new sealing ring (gasket?) to place between the units and the horn. When I resetup my setsystem I will measure with and without these.

Any information about the whereabouts of GPA would be welcome.

Regards, Coen

[Earl K]

Hi Earl,
<<SNIP>>

As a matter of fact I never received the GPA replacement diaphragms.

<<SNIP>>

Any information about the whereabouts of GPA would be welcome.

Regards, Coen

Sorry to hear about this . Maybe the diaphragms were simply never shipped .

- GPA is located at ;

GREAT PLAINS AUDIO ™
7127 NORTHWEST THIRD ST.
OKLAHOMA CITY, OKLAHOMA 73127

(405) 789-0221 or (405) 787-0987

- I'm not that surprised GPA didn't respond to your emails ( they're widely known for ignoring emails ) .
- ( It's said ) you have to telephone them to get their attention.

- If you can't get any action on your own , contact Todd White ( this forums webmaster ) and ask if he will intervene on your behalf ( alternately, Altec Best may want a crack at helping you out , so as to help maintain GPA's reputation ) .

<> EarlK

[Coendert2011]

Thanks for the information and tips!

i'm located in Europe so I'll try to phone them this afternoon or next week.

Regards, Coen

[Earl K]

Thanks for the information and tips!

i'm located in Europe so I'll try to phone them this afternoon or next week.

Regards, Coen

Coen, were you ever charged for these 2 diaphragms ?


If not, you may just want to leave "sleeping dogs lay" ( since I doubt you really need a new pair of diaphragms / all things considered ) .

I just ordered two new GPA diaphragms.

They were a bit hesitant to sell them to me, assuming I did not like the 288 character. Kudos to that attitude, wich I think is a good customer relation is all about!
<<SNIP>>

- As you previously stated ( from your first contact with them over this order from post# 81) GPA were hesitant to sell you new diaphragms fearing you may simply not enjoy the legacy sound of the 288 .

- Perhaps GPA figured they were doing you a favour by not shipping you superfluous parts .

<> EarlK

[stéphane Rame]

- I'm not that surprised GPA did not respond to your emails (they're Widely known for ignoring emails).


They have asked questions about their eBay store page.
They always respond.

St?phane

[Coendert2011]

Coen, were you ever charged for these 2 diaphragms ?


If not, you may just want to leave "sleeping dogs lay" ( since I doubt you really need a new pair of diaphragms / all things considered ) .



- As you previously stated ( from your first contact with them over this order from post# 81) GPA were hesitant to sell you new diaphragms fearing you may simply not enjoy the legacy sound of the 288 .

- Perhaps GPA figured they were doing you a favour by not shipping you superfluous parts .

<> EarlK

I just checked and I have been charged for the units conform the invoice. It is on my cc incoice of the end of June.


Regards, Coen

[Earl K]

I just checked and I have been charged for the units conform the invoice. It is on my cc incoice of the end of June.


Regards, Coen

Ahhh, okay . I guess you don't have any option but to pursue the issue with GPA .

<> EarlK

[Altec Best]

( alternately, Altec Best may want a crack at helping you out , so as to help maintain GPA's reputation ) .

You know Earl I'm always here to help anyone who asks for it..

FYI ~ Todd is taking a break from the daily duties.So I can pretty much help anyone with any issues they may have with the Altec User board.