In series/parallel raising sensitivity question

[bill poster]

Hi guys, I've forgotten how all this works.. :o
question is, if I have two full range drivers which are 8 ohm and 85 dB and two bass units which are 8 ohm and 88dB(per side), is there any way to raise the sensitivity of the small units and keep the impedance of all drivers the same? :confused:

[MGrant1957]

If you have to balance them, just slap an L-pad on the bass units, and adjust to taste. Quick, easy, and cheap.

[Servicetech]

Never attenuate bass units with an L-pad. 3db of Baffle Step will take care of the more sensitive bass unit.

[bill poster]

Never attenuate bass units with an L-pad. 3db of Baffle Step will take care of the more sensitive bass unit.

yes, I don't want to reduce sensitivity. So having 3dB higher in the bass is ok.. great, i didnt take into account baffle step. I will have to look at the frequency of each and work out where to cross over (1st order)
thanks !

[Chris Roemer]

yes, I don't want to reduce sensitivity. So having 3dB higher in the bass is ok.. great, i didnt take into account baffle step. I will have to look at the frequency of each and work out where to cross over (1st order)
thanks !

1st order crossovers don't work.

If you tell us exactly what you're up to, someone can probably help you.


Chris

[bill poster]

1st order crossovers don't work.

If you tell us exactly what you're up to, someone can probably help you.


Chris

Exactly?
I want to do this 2 way floorstander build in future, when the new gen 3 Mark Audio CHR 70 comes out in July.

2x chr70 per side 8 ohm 85.5dB approx
2x Fountek FW200 per side 8 ohm 88 dB approx
Hopefully the baffle step difference will mean that the extra sensitivity of the founteks is not a problem.

CHR70's in a sealed, Founteks in BR's (curved wall mdf/corian cabinet)

simple 1st order similar to some Jordan watts designs
Not sure what x/o point but around 400 hz or possibly a bit lower.
frequency response F3 25- 25000 hz

I'm thinking this should have very high sound quality, pretty cheap to build (UK money, around £400 for the drivers, and £900 total including the cabs etc.

[Servicetech]

I've had mixed results with 1st order crossovers. The drivers have to play nice together for it to work. At the price range your doing build a proven design. Experimenting is for buyout and other low cost drivers.

[bill poster]

I would call it a low budget high end build;) I've built speakers before, but I'm not really au fait with crossover design, hence the thread.
The CHR70 is one of the cheapest decent sounding units we can get in europe. The fountek is similar- if I went cheaper it would be a false economy imo. I'm deliberately going for drivers which should match, If a 1st order doesnt integrate, I will go 2nd or 3rd.

[fntn]

1st order crossovers don't work.

Chris

Really???

http://zaphaudio.com/Waveguidetmm.html

[Servicetech]

I would call it a low budget high end build;) I've built speakers before, but I'm not really au fait with crossover design, hence the thread.
The CHR70 is one of the cheapest decent sounding units we can get in europe. The fountek is similar- if I went cheaper it would be a false economy imo. I'm deliberately going for drivers which should match, If a 1st order doesnt integrate, I will go 2nd or 3rd.

UK money, around £400 for the drivers, and £900 total including the cabs etc. 650 pounds is about $1,000, not exactly low budget IMHO.

http://www.marketwatch.com/investing/currency/GBPUSD

[bill poster]

We can't get the same deals as you lucky guys in the states, so 400 quid/$650 dollars for 8 high quality drive units sounds very ok to me.

This hobby is about the pleasure of realising an idea, experimenting and taking some risks:cool: