A 604E in 828 cabinet horn loading question.

I think it?s time to try my 604Es as a duplex speaker in my 828 cabinets. Currently they are installed as I have been using the 604Es as a woofer only in the 828s. I have not tried them as duplex speakers in this cabinet. Will the 828 horn add additional loading to the duplex high frequency horn. Can I safely lower the crossover point below the 1200Hz that I believe was used for the 604Es to load the horn. I?m bi-amping using a Behringer DCX2496 so lots of options on slopes and cross points, and I thought it would be interesting to see how the crossover point effect the sound if it?s safe. I don?t play my music extremely loud. Any thoughts?

The 604E has a 1500 Hz XO, so no without significantly increasing the size of the HF waveguide [WG] and even then not a good plan going below ~900-1000 Hz where it would best blend to the woofer.

The 825/828 only loads over a narrow BW centered at ~175 Hz: http://2.bp.blogspot.com/-FhqQirgvf-...7-response.png

GM

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Originally Posted by GM

The 604E has a 1500 Hz XO, so no without significantly increasing the size of the HF waveguide [WG] and even then not a good plan going below ~900-1000 Hz where it would best blend to the woofer.

The 825/828 only loads over a narrow BW centered at ~175 Hz: http://2.bp.blogspot.com/-FhqQirgvf-...7-response.png

GM

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Thanks GM. I figured if you chimed in I would get the strait scope. I kinda figured that the 828 horn would not offer additional loading just based on its physical size. Yep, My mistake the 604e does use the N-1500 crossover. Had to pull them out of a box to confirm that's what mine came with. Going to go ahead and play around with them being careful not to cross them over to low. Should be interesting even though I don't think I will use them this way long term. Thanks again!

Your 604's fit in 828 cabs? Mine bolt up just fine but the woofer sticks out too much to put the back on the cabinet.

Running yours backless? :D

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Originally Posted by Elitopus1

Your 604's fit in 828 cabs? Mine bolt up just fine but the woofer sticks out too much to put the back on the cabinet.

Running yours backless? :D

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I thought maybe someone would ask this question. I took the attached picture before my original post and planned to include it as figured there was a good chance the question would come up, but figured why clutter things up. I basically cut a square hole in the back panel and added a box to provide room for the 604E.

Thats a good idea;)

Historically, recycling soup, peanut, cashew, etc., cans lined with damping and stuck on with elastic bathroom or similar caulk has been the most popular. I forget which Altec cab came with a screw on molded plastic cap [9848?].

GM

Barcelona has a coolwhip dish, they boxed in a 1 inch extension between the rear braces on the 9846.

http://www.hostboard.com/forums/hbmc.../2017/06/2.jpg

http://www.hostboard.com/forums/hbmc.../2017/06/3.jpg

And the Valencia has the cutout in the back that is baffle thickness. It would be pretty easy to build a little box to make room for an 802.

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Originally Posted by Elitopus1

And the Valencia has the cutout in the back that is baffle thickness. It would be pretty easy to build a little box to make room for an 802.

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Yes, correct on the Valencias.

The Valencia pair I bought for a friend in May, 2017, had a DIY MDF " box " added to a DIY rear cover, so it could fit an 802 instead of an 806. We added another 3/4 inch depth to the box, so my friend can run 802s or rebuilt Emilar EA175-8s, on his Valencias' 811 horns.


I finished building his SET amp for them, just yesterday, and am breaking his new "for ALTEC" amp in on my VOTTs, Uses Type 46 as a Final stage, direct coupled and only two stages. Am very pleased so far.


Jeff Medwin......Low Ohms

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Quote:

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Originally Posted by GM

The 604E has a 1500 Hz XO, so no without significantly increasing the size of the HF waveguide [WG] and even then not a good plan going below ~900-1000 Hz where it would best blend to the woofer.

The 825/828 only loads over a narrow BW centered at ~175 Hz: http://2.bp.blogspot.com/-FhqQirgvf-...7-response.png

GM

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Hello GM,

The response graph you show confuses me. It shows a green line adding response starting out about 1 kHZ. I see nothing showing the effect of a A7 bass horn, around 175 HZ, except a " bump" in the graph there. Is this the correct response chart you wanted to post?

What am I ( and perhaps others ) missing here ??

TIA.

Jeff Medwin.....Low Ohms.

The OP was asking if the 828 horn would help load the 604 horn enough for him to lower the xover point to 1200 cycles. I think GM was saying that with the 828 horn loading centered around 175 hz, this would not help load the duplex horn

Correct.

GM