Naim DBL - ATC revision/upgrade

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi

New here but have been DIYing for many years and have made (built) many speakers kits. Some 12 years ago ended up building a 3 way based on the Naim DBL, though successful I have always felt the mid range was lacking for such a hi end speaker. (IMO) For some reason I didn’t get on with these speakers (I was running them passive at the time with a Naim xover) I recall doing some measurements and found the xover points IIRC were 550&2k . And packed them up not to be used again…..but a rekindled interest in hi fi and the fact that I can now run them active could revive them from retirement.

An externally hosted image should be here but it was not working when we last tested it.


They are a SB type (separate box) mechanically decoupled speaker built on a 25mm square steel chassis. The bass enclosure is supported on spikes, which are coupled to the chassis, which in turn is spiked to the floor. The bass ‘chamber’ (L shaped) is fixed to the chassis. Between the Bass Box and the chamber is a mechanical restriction (filter) Similar to that used in the SBL. Thus allowing the bass driver to act as if it’s in a small box but allowing it to resonate into the chamber as if it was in a large box.
The Mid and High drivers are in one enclosure again decoupled from the main ‘L’ chamber via a spikes sub chassis. Each of these divers are mounted on a ‘suspension system’ ….to eliminate box interaction, not sure this works??? I was trying to replicate the Naims theory at the time.

The drivers are :-
ATC 100/375 not sure of the exact model till I get them apart.
Naims own MID, know idea of model or spec & no’s
Scanspeak 2010/851300 tweeter (non ferro)

The plan is to replace the mid….and revise the xover points. The mid is Naims own driver, looks like a KEF B110 but its not with the ATC 75-150 and maybe the tweeter. The easiest way is to make an all new mid high enclosure and to replicate the ATC off set baffle layout.

I’ve already had great info and advise from a member here and another forum (PFM) Thanks Colin but any further info regarding the ATC mid unit would be of help……IE 8 or 16ohms

Graham
 
Last edited:
Check Proac EBS (studio 3) crossover , I would start from there. I had this speaker for a while and It's a good allarounder, great with rock ,pop and competent with classical. Dome mid provides vivid. life like and very transparent (I don't like this word but it somehow describes ATC mid ) sound. Proac uses 16 Ohm version . You will probably have to adjust the tweeter level to your taste. Rgrds, L
 
Many thanks.....Thats looks almost bang on and as you say a good place to start. With luck I've got/hope to get a pair of ATC 75-150 drivers....in the next few days 16Ohm's which will fit the bill real nice> I've got a pair of Scanspeak 2008's so its may well be only the bass driver I might need to look at....:)
 
Hi

New here but have been DIYing for many years and have made (built) many speakers kits. Some 12 years ago ended up building a 3 way based on the Naim DBL, though successful I have always felt the mid range was lacking for such a hi end speaker. (IMO) For some reason I didn’t get on with these speakers (I was running them passive at the time with a Naim xover) I recall doing some measurements and found the xover points IIRC were 550&2k . And packed them up not to be used again…..but a rekindled interest in hi fi and the fact that I can now run them active could revive them from retirement.

An externally hosted image should be here but it was not working when we last tested it.


They are a SB type (separate box) mechanically decoupled speaker built on a 25mm square steel chassis. The bass enclosure is supported on spikes, which are coupled to the chassis, which in turn is spiked to the floor. The bass ‘chamber’ (L shaped) is fixed to the chassis. Between the Bass Box and the chamber is a mechanical restriction (filter) Similar to that used in the SBL. Thus allowing the bass driver to act as if it’s in a small box but allowing it to resonate into the chamber as if it was in a large box.
The Mid and High drivers are in one enclosure again decoupled from the main ‘L’ chamber via a spikes sub chassis. Each of these divers are mounted on a ‘suspension system’ ….to eliminate box interaction, not sure this works??? I was trying to replicate the Naims theory at the time.

The drivers are :-
ATC 100/375 not sure of the exact model till I get them apart.
Naims own MID, know idea of model or spec & no’s
Scanspeak 2010/851300 tweeter (non ferro)

The plan is to replace the mid….and revise the xover points. The mid is Naims own driver, looks like a KEF B110 but its not with the ATC 75-150 and maybe the tweeter. The easiest way is to make an all new mid high enclosure and to replicate the ATC off set baffle layout.

I’ve already had great info and advise from a member here and another forum (PFM) Thanks Colin but any further info regarding the ATC mid unit would be of help……IE 8 or 16ohms

Graham

Hi Graham,

Be interested to learn more about your project and how it has progressed over the last few years

ATB

Simon
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.