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Old 10th November 2005, 02:30 PM   #11
henkel is offline henkel  Malaysia
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The driver is a Scanspeak 18W/5535 7" mid. Not sure if it's 8ohms, as I can't find it on www.d-s-t.com

The nearest one I could see is 18W/8535 which is 8 ohms.

The reason is more for level matching between tweeter (Scanspeak 2904/6000) and mid. The mids don't seem to play loud enough. That's why. Both mid and tweeter is powered by a 60W x 4channel amp.
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Old 10th November 2005, 02:52 PM   #12
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The question is, what crossover are you using? IF you are using a purely active one, you need to attenuate it in the preamp.

Most all tweeters are more sensistive than the woofers.
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Old 11th November 2005, 03:45 AM   #13
henkel is offline henkel  Malaysia
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bjackson,

Wow! you are fast!

O.K. here's the full details of my ICE system,

HU- Alpine 7998R
AMPS- Sony SD 22X (for subs) & Sony SD 46 (for front stage)
2 x 200W RMS 4 x 60W RMS
Speakers- Tweeter Scanspeak 2904/6000
Mid Scanspeak 18W5535
Sub CDT MS 100, one pair 10".

The system is configured to run as active, High-Mid-Low. X-overs are used in the HU built-ins, as are the EQs(5 band parametric) and Time Alignment.

While I can use the output level of the HU to compensate for level matching, it did not turn out as well as I liked. I do not know how to tell you in writing how it sounds, but here's a try.

The level of sound coming from the mids while is suficient as matching the tweeters, does not provide the same energy or should I say "kick" enough to be coherent to the music as whole.

I was wondering if tricking the amp loads by lowering the ohm value of the mids would do it, and hence my original posting.

This should really be in the car audio section, but since this is the loudspeaker section of the forum, I'd thought I'd be more specific.

Just trying to see if there's another way, as I try to use what 've got. I hope you understand.

Thanks for looking and any more ideas are welcome.
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Old 11th November 2005, 03:56 AM   #14
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I think that you are experiancing bad car acoustics. You might want to try using the EQ, especially with a calibration microphone. You can pick up a Behringer ECM8000 mic for 30-40 and a preamp for 50-60 and use a computer RTA....

You gotta correct for car acoustics though. Best bet would be to use a Behringer DCX or DEQ 2496 but those are expensive (300 or so). Well worth it for such nice drivers though...
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Old 11th November 2005, 07:56 AM   #15
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for current scan drivers, the first 2 letters are the driver size in cm. 18W = 18 cm woofer (vs 18m would be 18 cm midrange). The next number is nominal impedance (15W/4531 is 4 ohm, 15W/8531 is 8 ohm). The rest of the numbers have meaning as well but I don't remember them by heart. There is a spec sheet on the d-s-t web site that has that information. Anyway if the 18W/5535 is similar to current drivers (which it may not be) then the nominal impedance is 5 ohms.

Your best bet is to buy a cheap 3-way outboard crossover with independent level controls and possibly a small 25-50W amp for your tweets, then bridge the 4x60 amp for the mids.
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Old 11th November 2005, 09:36 AM   #16
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All the advice is good but I'd like to clarify djackson's point that 3dB is the smallest change you can hear. That is simply not true, and I'm not a golden eared freak. You can hear 1dB change quite easily.
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Old 11th November 2005, 12:24 PM   #17
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I said smallest change easily heard. Under the right conditions, yes you can hear a difference.
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Old 1st March 2013, 07:15 AM   #18
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Hi,

I have an amplifier that gives 20W into 4ohm, 12W into 8 ohm, or 6W into 20 ohm. Now I have a Speaker that is 15W @20 Ohms. Now is there a way make full use of the speaker using the existing amplifier?

Would really appreciate if if someone could help me here.
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Old 1st March 2013, 08:22 AM   #19
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Ohm's law can't be defeated
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Old 1st March 2013, 08:42 AM   #20
PLB is offline PLB  United Kingdom
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Hi kbharaninath,

See post #7. Using a step-up autotransformer is the only way to solve your problem.

Regards

Peter

Quote:
Originally Posted by kbharaninath View Post
Hi,

I have an amplifier that gives 20W into 4ohm, 12W into 8 ohm, or 6W into 20 ohm. Now I have a Speaker that is 15W @20 Ohms. Now is there a way make full use of the speaker using the existing amplifier?

Would really appreciate if if someone could help me here.
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