Hartke B900

[Dave With The Blind Eye]

Newbie calling!

I have browsed this forum occasionally, and would like to start by thanking folks for the wealth of information and experience that they so readily share. I have learned much here that I was not taught in school!

I have not posted before, but am hoping that somebody on here has, or can provide information about the Hartke B900 bass combo (because Hartke can't or won't). I'm posting here because I don't think the B900 quite falls into the "vintage" amps category. If you want to move this question to a different heading feel free.

I have been given a Hartke 15" speaker, it is the 360069, the one that was used in the now discontinued B900 bass amp.

I would like to use the speaker to build a 1 x 15 cab, but drew a blank when searching for information about the speaker. Google eventually informed me that the speaker is 8ohm, but other than that I couldn't find any info.

I contacted Hartke and they kindly informed me that the speaker is no longer available (I had already told them this in my email asking whether they had an old data sheet kicking around).

Does anyone out there have one of these speakers or a Hartke B900? Can anyone give me any more information? Was the B900 ported or not? Any clues at all? I could just build a cab and pop it in but would like to know as much as possible about the speaker before I start cutting plywood.

Thanks again for all the shared expertise!

[Jazz P Bass]

The B900 is a 90 watt amplifier so I would not expect too much from the speaker (wattage capability)

The cabinet is sealed at the rear.
Here are some pics that show the two front ports.

[J M Fahey]

Agree and add, just an educated guess:

1) as mentioned above, if used in a 90W amp, it probably stands 100/120W and not more.

2) it looks like a decent generic 15" Bass speaker, so it should sound good in a decent cabinet.

3) without measuring anything, but knowing Bass combos are never optimum size because of portability needs, but "as small as possible", I guess building a cabinet some 50% larger capacity (in liters or cubic feet) would be fine, so based on B90 size (which should be available online) you can estimate your own cabinet size.

4) again without measuring, tuning your cabinet to 60/65Hz should work well.

Thiele-Small parameters let you calculate a "perfect" maximally flat cabinet; tuning I suggested above will work, but probably have some hump in the response.
No big deal, since this is a Bass Guitar cabinet, not a Studio Monitor or Hi Fi cabinet, a small hump in the Bass frequencies wonīt hurt and might in fact sound cool

After you build it, tells us how it sounds and maybe post a couple pictures

FWIW Korg UK sells them new in box for 20 GBP .
Which does not mean they are bad, at all, just that they have a small stock they donīt have use for.
https://www.ebay.co.uk/itm/Hartke-36...-/112801567216

[Dave With The Blind Eye]

Thank you for the useful information and encouragement!

I expected that the speaker would be "ok but not amazing" because otherwise it would not have landed with me as easily as it has!

Good to know that it was used in a ported design. I have never done a ported cab before and sooner or later you reach that point in life where you just have to take that step and build a ported cab.

I will see where I can get some plywood and make a start at the weekend.

Does anyone have a link to the Thiel / Small information or a pdf that they wouldn't mind sharing?

Thanks again!!