Add On Supertweeter For Hartsfield?

Hello!
I am new to this forum, and I just picked up a pair of fair condition JBL Hartsfield lately. I know the Hartsfield is limit on the high frequency and I am considering to add a supertweeter on the Hartsfield to extend the high end. However, I am not sure which supertweeter is going to track the character of the Hartsfield. These are the supertweeters I am thinking to put on the Hartsfield.

1) Decca DK30 Horm supertweeter
2) Tannoy ST-200 dome supertweeter
3) Sequerra T-1
4) JBL horn supertweeter made recently eg. UT045 Be

I have few more questions about the Hartsfield.

What is the frequency response of this speaker? Also what is the min and max impedance of this speaker? What about the sensitivity?

Is 2 watts Single Ended amplifier capable to drive this speaker?

Thanks in Advance!

The Hartsfield originaly was a two way. 150-4c woofer & 375 HF. Later a 075 tweeter was added. I would suggest replacing the 075 with the TAD 703. The upper HF would extend to 40K. A modification in crossover may be needed.

We are a Tannoy dealer where I work, so I've actually heard the Tannoy supertweeters... I can say, they definitely do work VERY well. With a Hartsfield, I'd guess you'd want the lowest frequency point on the ST200 (which should be ~12KHz), and the level set at the highest point (which is 93.5 dB, IIRC)... and it should do pretty well, as far as matching the system is concerned. The ST100 and ST200 have exhibited very good dynamic behaviour... they should have no problem working with horn drivers and efficient speakers, given that Tannoy used the same design unit in the Chuhchill and in the Kingdom/Prestige series speakers, which range up to around 100 dB sensitivity on the larger models.

Otherwise, if you wanted to keep it "in the family", I'd suggest using an 077/2405 slot tweeter, rather than an 075... much more HF extension. It'll usually work with the same crossover as the 075 (N7000/N8000 or whatnot) in the Hartsfield....

Regards,
Gordon.

the cts piezos really make guitars stand out

the jbl tweeter might be best

Congrats on your recent aquisition!:applaud:

Here is a photo (not mine) showing a Hartsfield with an 075 added to one side of the midrange horn. I don't know if this is a factory installation, but I think this is the way to go.

I'd be thinkin' about adding HF boost to the 375 first.

What's the driver impedances and XO frequency?

These maybe?

http://cgi.ebay.com/ws/eBayISAPI.dll...773317480&rd=1

http://cgi.ebay.com/ws/eBayISAPI.dll...772971890&rd=1

Gordon,
Thank you for your suggestion! I think the ST-200 should adjust up to 95db instead of 93.5db if not mistaken.

What I concern about the ST-200 and Hartsfield are their effiicency seem not track. I guess the Hartsfiled is extremely efficient, someone told me that it is 110db for sensitivity. however, the ST-200 can capable up to 95db only. As a result, the Hartsfield can play louder than the Tannoy ST-200 even the ST-200 at 95db setting. This is what I worry about putting the ST-200 on the Hartsfield.

What do you think?

Thanks Again!

Quote:

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Originally Posted by GordonW

We are a Tannoy dealer where I work, so I've actually heard the Tannoy supertweeters... I can say, they definitely do work VERY well. With a Hartsfield, I'd guess you'd want the lowest frequency point on the ST200 (which should be ~12KHz), and the level set at the highest point (which is 93.5 dB, IIRC)... and it should do pretty well, as far as matching the system is concerned. The ST100 and ST200 have exhibited very good dynamic behaviour... they should have no problem working with horn drivers and efficient speakers, given that Tannoy used the same design unit in the Chuhchill and in the Kingdom/Prestige series speakers, which range up to around 100 dB sensitivity on the larger models.

Otherwise, if you wanted to keep it "in the family", I'd suggest using an 077/2405 slot tweeter, rather than an 075... much more HF extension. It'll usually work with the same crossover as the 075 (N7000/N8000 or whatnot) in the Hartsfield....

Regards,
Gordon.

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Thanks Guys for all useful information!

Quote:

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Originally Posted by Tube747

Gordon,
Thank you for your suggestion! I think the ST-200 should adjust up to 95db instead of 93.5db if not mistaken.

What I concern about the ST-200 and Hartsfield are their effiicency seem not track. I guess the Hartsfiled is extremely efficient, someone told me that it is 110db for sensitivity. however, the ST-200 can capable up to 95db only. As a result, the Hartsfield can play louder than the Tannoy ST-200 even the ST-200 at 95db setting. This is what I worry about putting the ST-200 on the Hartsfield.

What do you think?

Thanks Again!

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Actually, that is correct. Just verified it with Tannoy, in Kirschner, Ont... their tech guy said that putting an ST200 would result in basically, not being able to hear the supertweeter at all... in it being "swamped" by the 100+ dB sensitivity of the Hartsfield. In his words, a "bad idea".

Regards,
Gordon.